| Message ID | a55dc5d1a9f02dc4d71d5c21064bffebe5a7b149.1467135898.git.moinejf@free.fr (mailing list archive) |
|---|---|
| State | Rejected |
| Headers | show |
On Tue, Jun 28, 2016 at 05:37:35PM +0200, Jean-Francois Moine wrote: > +/* --- prepare / enable --- */ > +int ccu_prepare(struct clk_hw *hw) > +{ > + struct ccu *ccu = hw2ccu(hw); > + > + if (!ccu->reset_reg && !ccu->bus_reg) > + return 0; > + > +#if CCU_DEBUG > + pr_info("** ccu %s prepare\n", clk_hw_get_name(&ccu->hw)); > +#endif > + spin_lock(&ccu_lock); > + if (ccu->reset_reg) > + writel(readl(ccu->base + ccu->reset_reg) | > + BIT(ccu->reset_bit), > + ccu->base + ccu->reset_reg); > + if (ccu->bus_reg) > + writel(readl(ccu->base + ccu->bus_reg) | BIT(ccu->bus_bit), > + ccu->base + ccu->bus_reg); Like I already said, this is a no-go. > + > +/* --- PLL --- */ > +static int ccu_pll_find_best(struct ccu *ccu, > + unsigned long rate, > + unsigned long parent_rate, > + struct values *p_v) > +{ > + int max_mul, max_div, mul, div, t; > + int n = 1, d1 = 1, k = 1, m = 1, p = 0; > + int max_n = 1 << ccu->n_width; > + int max_d1 = 1 << ccu->d1_width; > + int max_k = 1 << ccu->k_width; > + int max_m = 1 << ccu->m_width; > + int max_p = 1 << ccu->p_width; > + > + if (ccu->features & CCU_FEATURE_N0) > + max_n--; > + > + /* compute n */ > + if (max_n > 1) { > + max_mul = max_n * max_k; > + if (rate > parent_rate * max_mul) { > + pr_err("%s: Clock rate too high %ld > %ld * %d * %d\n", > + clk_hw_get_name(&ccu->hw), > + rate, parent_rate, max_n, max_k); > + return -EINVAL; > + } > + max_div = max_m * max_d1 << max_p; > + if (max_div > 1) { > + unsigned long lmul, ldiv; > + > + rational_best_approximation(rate, parent_rate, > + max_mul - 1, > + max_div - 1, > + &lmul, &ldiv); > + mul = lmul; > + div = ldiv; > + if (ccu->n_min && mul < ccu->n_min) { > + t = (ccu->n_min + mul - 1) / mul; > + mul *= t; > + div *= t; > + } > + } else { > + mul = (rate + parent_rate - 1) / parent_rate; > + div = 1; > + } > + > + /* compute k (present only when 'n' is present) */ > + if (max_k > 1) { > + int k_min, k_opt, delta_opt = 100, delta; > + > + k = (mul + max_n - 1) / max_n; > + k_opt = k_min = k; > + for (k = max_k; k > k_min; k--) { > + n = (mul + k - 1) / k; > + t = n * k; > + delta = t - mul; > + if (delta == 0) { > + k_opt = k; > + break; > + } > + if (delta < 0) > + delta = -delta; > + if (delta < delta_opt) { > + delta_opt = delta; > + k_opt = k; > + } > + } > + k = k_opt; > + n = (mul + k - 1) / k; > + } else { > + n = mul; > + } > + } else { > + div = (parent_rate + rate - 1) / rate; > + } > + > + /* compute d1 (value is only 1 or 2) */ > + if (max_d1 > 1) { > + if (div % 2 == 0) { > + d1 = 2; > + div /= 2; > + } > + } > + > + /* compute p */ > +/* p = 0; */ > + while (div % 2 == 0 && p <= max_p) { > + p++; > + div /= 2; > + } > + > + /* compute m */ > + if (max_m > 1) { > + if (div <= max_m) > + m = div; > + else > + m = max_m; > + div /= m; > + } > + > + /* adjust n */ > + n = DIV_ROUND_CLOSEST((rate << p) * m * d1, parent_rate); > + n = DIV_ROUND_CLOSEST(n, k); > + > + p_v->n = n; > + p_v->d1 = d1; > + p_v->k = k; > + p_v->m = m; > + p_v->p = p; > + > + return 0; > +} So. In order to move away from an unmaintainable mess, we create a new unmaintainable mess? Looks like the way to go. > +const struct clk_ops ccu_pll_ops = { > + .prepare = ccu_prepare, > + .unprepare = ccu_unprepare, > + .enable = ccu_enable, > + .disable = ccu_disable, > +/* .is_enabled = NULL; (don't disable the clocks at startup time) */ Why? > +/* --- mux --- */ > +static void ccu_mux_adjust_parent_for_prediv(struct ccu *ccu, > + int parent_index, > + unsigned long *parent_rate) > +{ > + const struct ccu_extra *extra = ccu->extra; > + int prediv = 1; > + u32 reg; > + > + if (!(extra && > + (ccu->features & (CCU_FEATURE_MUX_FIXED_PREDIV | > + CCU_FEATURE_MUX_VARIABLE_PREDIV)))) > + return; > + > + reg = readl(ccu->base + ccu->reg); > + if (parent_index < 0) > + parent_index = (reg >> ccu->mux_shift) & > + ((1 << ccu->mux_width) - 1); > + > + if (ccu->features & CCU_FEATURE_MUX_FIXED_PREDIV) > + prediv = extra->fixed_div[parent_index]; > + > + if (ccu->features & CCU_FEATURE_MUX_VARIABLE_PREDIV) > + if (parent_index == extra->variable_prediv.index) { > + u8 div; > + > + div = reg >> extra->variable_prediv.shift; > + div &= (1 << extra->variable_prediv.width) - 1; > + prediv = div + 1; > + } > + > + *parent_rate /= prediv; > +} > + > +/* --- periph --- */ > +static unsigned long ccu_m_round_rate(struct ccu *ccu, > + unsigned long rate, > + unsigned long parent_rate) > +{ > + int m; > + > + /* > + * We can't use divider_round_rate that assumes that there's > + * several parents, while we might be called to evaluate > + * several different parents. > + */ > + m = divider_get_val(rate, parent_rate, > + ccu->div_table, ccu->m_width, ccu->div_flags); > + > + return divider_recalc_rate(&ccu->hw, parent_rate, m, > + ccu->div_table, ccu->div_flags); > +} > + > +static unsigned long ccu_mp_round_rate(struct ccu *ccu, > + unsigned long rate, > + unsigned long parent_rate) > +{ > + struct values v; > + int ret; > + > + ret = ccu_pll_find_best(ccu, rate, parent_rate, &v); > + if (ret) > + return 0; > + > + return parent_rate / v.m >> v.p; > +} > + > +unsigned long ccu_periph_recalc_rate(struct clk_hw *hw, > + unsigned long parent_rate) > +{ > + struct ccu *ccu = hw2ccu(hw); > + int m, p; > + u32 reg; > + > + ccu_mux_adjust_parent_for_prediv(ccu, -1, &parent_rate); > + > + if (!ccu->m_width && !ccu->p_width) > + return parent_rate; > + > + reg = readl(ccu->base + ccu->reg); > + m = (reg >> ccu->m_shift) & ((1 << ccu->m_width) - 1); > + > + if (ccu->p_width) { > + reg = readl(ccu->base + ccu->reg); > + p = (reg >> ccu->p_shift) & ((1 << ccu->p_width) - 1); > + > + return parent_rate / (m + 1) >> p; > + } > + > + return divider_recalc_rate(hw, parent_rate, m, > + ccu->div_table, ccu->div_flags); > +} > + > +int ccu_periph_determine_rate(struct clk_hw *hw, > + struct clk_rate_request *req) > +{ > + struct ccu *ccu = hw2ccu(hw); > + > + unsigned long best_parent_rate = 0, best_rate = 0; > + struct clk_hw *best_parent; > + unsigned int i; > + unsigned long (*round)(struct ccu *, > + unsigned long, > + unsigned long); > + > + if (ccu->p_width) > + round = ccu_mp_round_rate; > + else if (ccu->m_width) > + round = ccu_m_round_rate; > + else > + return __clk_mux_determine_rate(hw, req); > + > + for (i = 0; i < clk_hw_get_num_parents(hw); i++) { > + unsigned long new_rate, parent_rate; > + struct clk_hw *parent; > + > + parent = clk_hw_get_parent_by_index(hw, i); > + if (!parent) > + continue; > + > + parent_rate = clk_hw_get_rate(parent); > + ccu_mux_adjust_parent_for_prediv(ccu, i, &parent_rate); > + new_rate = round(ccu, req->rate, parent_rate); > + > + if (new_rate == req->rate) { > + best_parent = parent; > + best_parent_rate = parent_rate; > + best_rate = new_rate; > + goto out; > + } > + > + if ((req->rate - new_rate) < (req->rate - best_rate)) { > + best_rate = new_rate; > + best_parent_rate = parent_rate; > + best_parent = parent; > + } > + } > + > + if (best_rate == 0) > + return -EINVAL; > + > +out: > + req->best_parent_hw = best_parent; > + req->best_parent_rate = best_parent_rate; > + req->rate = best_rate; > + > + return 0; > +} Sooo, basically my code. > +int ccu_periph_set_rate(struct clk_hw *hw, unsigned long rate, > + unsigned long parent_rate) > +{ > + struct ccu *ccu = hw2ccu(hw); > + const struct ccu_extra *extra = ccu->extra; > + struct values v; > + u32 mask; > + int ret; > + > + if (!ccu->m_width && !ccu->p_width) > + return 0; > + > + ccu_mux_adjust_parent_for_prediv(ccu, -1, &parent_rate); > + > + if (extra && (ccu->features & CCU_FEATURE_MODE_SELECT)) { > + /* fixme: should use new mode */ > + if (rate == extra->mode_select.rate) > + rate /= 2; > + } That needs synchronisation with the MMC driver. How are you dealing with this? > + > + if (ccu->p_width) { /* m and p */ > + ret = ccu_pll_find_best(ccu, rate, parent_rate, &v); > + if (ret) > + return ret; > + } else { /* m alone */ > + v.m = divider_get_val(rate, parent_rate, > + ccu->div_table, ccu->m_width, ccu->div_flags); > + v.p = 0; > + return 0; > + } > + > + mask = CCU_MASK(ccu->m_shift, ccu->m_width) | > + CCU_MASK(ccu->p_shift, ccu->p_width); > + > + if (ccu->features & CCU_FEATURE_SET_RATE_UNGATE) > + ccu_disable(hw); ungating means enable, and this is already dealt with by the core. > + > +/* --- fixed factor --- */ > +/* mul is n_width - div is m_width */ > +unsigned long ccu_fixed_factor_recalc_rate(struct clk_hw *hw, > + unsigned long parent_rate) > +{ > + struct ccu *ccu = hw2ccu(hw); > + > + return parent_rate / ccu->m_width * ccu->n_width; > +} > + > +long ccu_fixed_factor_round_rate(struct clk_hw *hw, > + unsigned long rate, > + unsigned long *parent_rate) > +{ > + struct ccu *ccu = hw2ccu(hw); > + > + if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) { > + unsigned long best_parent; > + > + best_parent = (rate / ccu->n_width) * ccu->m_width; > + *parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw), > + best_parent); > + } > + > + return *parent_rate / ccu->m_width * ccu->n_width; > +} > + > +int ccu_fixed_factor_set_rate(struct clk_hw *hw, unsigned long rate, > + unsigned long parent_rate) > +{ > + return 0; > +} > + > +const struct clk_ops ccu_fixed_factor_ops = { > + .disable = ccu_disable, > + .enable = ccu_enable, > +/* .is_enabled = NULL, */ > + > + .recalc_rate = ccu_fixed_factor_recalc_rate, > + .round_rate = ccu_fixed_factor_round_rate, > + .set_rate = ccu_fixed_factor_set_rate, > +}; This is redundant with the core. > +/* --- reset --- */ > +static inline > +struct ccu_reset *rcdev_to_ccu_reset(struct reset_controller_dev *rcdev) > +{ > + return container_of(rcdev, struct ccu_reset, rcdev); > +} > + > +static void ccu_set_reset_clock(struct ccu_reset *ccu_reset, > + int reg, int bit, int enable) > +{ > + u32 mask; > + > + if (!reg) /* compatibility */ > + return; > + > +#if CCU_DEBUG > + pr_info("** ccu reset %03x %d %sassert\n", > + reg, bit, enable ? "de-" : ""); > +#endif You have tracepoints for that. > + mask = BIT(bit); > + > + spin_lock(&ccu_lock); > + if (enable) > + writel(readl(ccu_reset->base + reg) | mask, > + ccu_reset->base + reg); > + else > + writel(readl(ccu_reset->base + reg) & ~mask, > + ccu_reset->base + reg); > + spin_unlock(&ccu_lock); > +} > + > +static int ccu_reset_assert(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + struct ccu_reset *ccu_reset = rcdev_to_ccu_reset(rcdev); > + const struct ccu_reset_map *map = &ccu_reset->reset_map[id]; > + > + ccu_set_reset_clock(ccu_reset, map->reg, map->bit, 0); > + > + return 0; > +} > + > +static int ccu_reset_deassert(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + struct ccu_reset *ccu_reset = rcdev_to_ccu_reset(rcdev); > + const struct ccu_reset_map *map = &ccu_reset->reset_map[id]; > + > + ccu_set_reset_clock(ccu_reset, map->reg, map->bit, 1); > + > + return 0; > +} > + > +const struct reset_control_ops ccu_reset_ops = { > + .assert = ccu_reset_assert, > + .deassert = ccu_reset_deassert, > +}; > + > +/* --- init --- */ > +int __init ccu_probe(struct device_node *node, > + struct clk_hw_onecell_data *data, > + struct ccu_reset *resets) > +{ > + struct clk_hw *hw; > + struct ccu *ccu; > + void __iomem *reg; > + int i, ret; > + > + reg = of_io_request_and_map(node, 0, of_node_full_name(node)); > + if (IS_ERR(reg)) { > + pr_err("%s: Clock mapping failed %d\n", > + of_node_full_name(node), (int) PTR_ERR(reg)); > + return PTR_ERR(reg); > + } > + > + /* register the clocks */ > + for (i = 0; i < data->num; i++) { > + hw = data->hws[i]; > +#if CCU_DEBUG > + if (!hw) { > + pr_err("%s: Bad number of clocks %d != %d\n", > + of_node_full_name(node), > + i + 1, data->num); > + data->num = i; > + break; > + } > +#endif > + ccu = hw2ccu(hw); > + ccu->base = reg; > + ret = clk_hw_register(NULL, hw); > + if (ret < 0) { > + pr_err("%s: Register clock %s failed %d\n", > + of_node_full_name(node), > + clk_hw_get_name(hw), ret); > + data->num = i; > + break; > + } > + } > + ret = of_clk_add_hw_provider(node, of_clk_hw_onecell_get, data); > + if (ret < 0) > + goto err; > + > + /* register the resets */ > + resets->rcdev.of_node = node; > + resets->base = reg; > + > + ret = reset_controller_register(&resets->rcdev); > + if (ret) { > + pr_err("%s: Reset register failed %d\n", > + of_node_full_name(node), ret); > + goto err; > + } > + > + return ret; What's the point of this, if we're not using (or exposing for that matter) any of it? I'm sorry, but the whole point of the initial serie was to rework and simplify things, precisely because dealing with the clk_factors code was just too difficult nowadays. And this doesn't solve anything on that aspect. We came with an approach that have all the maintainers involved agreeing on it, I don't see why we should start over. There's some useful features there (like tracing). But it's something that can be added, and should be done differently anyway. Maxime
Quoting Maxime Ripard (2016-06-28 13:45:02) > What's the point of this, if we're not using (or exposing for that > matter) any of it? > > I'm sorry, but the whole point of the initial serie was to rework and > simplify things, precisely because dealing with the clk_factors code > was just too difficult nowadays. And this doesn't solve anything on > that aspect. > > We came with an approach that have all the maintainers involved > agreeing on it, I don't see why we should start over. There's some > useful features there (like tracing). But it's something that can be > added, and should be done differently anyway. Yes, let's not delay Maxime's work any longer. Stephen and I have requested these changes to the sunxi clock drivers for a long time and now we have them. I intend to merge Maxime's v3 once it addresses the last round of review questions. Regards, Mike > > Maxime > > -- > Maxime Ripard, Free Electrons > Embedded Linux, Kernel and Android engineering > http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-clk" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, 28 Jun 2016 22:45:02 +0200 Maxime Ripard <maxime.ripard@free-electrons.com> wrote: > On Tue, Jun 28, 2016 at 05:37:35PM +0200, Jean-Francois Moine wrote: > > +/* --- prepare / enable --- */ > > +int ccu_prepare(struct clk_hw *hw) > > +{ > > + struct ccu *ccu = hw2ccu(hw); > > + > > + if (!ccu->reset_reg && !ccu->bus_reg) > > + return 0; > > + > > +#if CCU_DEBUG > > + pr_info("** ccu %s prepare\n", clk_hw_get_name(&ccu->hw)); > > +#endif > > + spin_lock(&ccu_lock); > > + if (ccu->reset_reg) > > + writel(readl(ccu->base + ccu->reset_reg) | > > + BIT(ccu->reset_bit), > > + ccu->base + ccu->reset_reg); > > + if (ccu->bus_reg) > > + writel(readl(ccu->base + ccu->bus_reg) | BIT(ccu->bus_bit), > > + ccu->base + ccu->bus_reg); > > Like I already said, this is a no-go. I don't see why: prepare/unprepare do the right job. > > + > > +/* --- PLL --- */ > > +static int ccu_pll_find_best(struct ccu *ccu, > > + unsigned long rate, > > + unsigned long parent_rate, > > + struct values *p_v) > > +{ > > + int max_mul, max_div, mul, div, t; > > + int n = 1, d1 = 1, k = 1, m = 1, p = 0; > > + int max_n = 1 << ccu->n_width; > > + int max_d1 = 1 << ccu->d1_width; > > + int max_k = 1 << ccu->k_width; > > + int max_m = 1 << ccu->m_width; > > + int max_p = 1 << ccu->p_width; > > + > > + if (ccu->features & CCU_FEATURE_N0) > > + max_n--; > > + > > + /* compute n */ > > + if (max_n > 1) { > > + max_mul = max_n * max_k; > > + if (rate > parent_rate * max_mul) { > > + pr_err("%s: Clock rate too high %ld > %ld * %d * %d\n", > > + clk_hw_get_name(&ccu->hw), > > + rate, parent_rate, max_n, max_k); > > + return -EINVAL; > > + } > > + max_div = max_m * max_d1 << max_p; > > + if (max_div > 1) { > > + unsigned long lmul, ldiv; > > + > > + rational_best_approximation(rate, parent_rate, > > + max_mul - 1, > > + max_div - 1, > > + &lmul, &ldiv); > > + mul = lmul; > > + div = ldiv; > > + if (ccu->n_min && mul < ccu->n_min) { > > + t = (ccu->n_min + mul - 1) / mul; > > + mul *= t; > > + div *= t; > > + } > > + } else { > > + mul = (rate + parent_rate - 1) / parent_rate; > > + div = 1; > > + } > > + > > + /* compute k (present only when 'n' is present) */ > > + if (max_k > 1) { > > + int k_min, k_opt, delta_opt = 100, delta; > > + > > + k = (mul + max_n - 1) / max_n; > > + k_opt = k_min = k; > > + for (k = max_k; k > k_min; k--) { > > + n = (mul + k - 1) / k; > > + t = n * k; > > + delta = t - mul; > > + if (delta == 0) { > > + k_opt = k; > > + break; > > + } > > + if (delta < 0) > > + delta = -delta; > > + if (delta < delta_opt) { > > + delta_opt = delta; > > + k_opt = k; > > + } > > + } > > + k = k_opt; > > + n = (mul + k - 1) / k; > > + } else { > > + n = mul; > > + } > > + } else { > > + div = (parent_rate + rate - 1) / rate; > > + } > > + > > + /* compute d1 (value is only 1 or 2) */ > > + if (max_d1 > 1) { > > + if (div % 2 == 0) { > > + d1 = 2; > > + div /= 2; > > + } > > + } > > + > > + /* compute p */ > > +/* p = 0; */ > > + while (div % 2 == 0 && p <= max_p) { > > + p++; > > + div /= 2; > > + } > > + > > + /* compute m */ > > + if (max_m > 1) { > > + if (div <= max_m) > > + m = div; > > + else > > + m = max_m; > > + div /= m; > > + } > > + > > + /* adjust n */ > > + n = DIV_ROUND_CLOSEST((rate << p) * m * d1, parent_rate); > > + n = DIV_ROUND_CLOSEST(n, k); > > + > > + p_v->n = n; > > + p_v->d1 = d1; > > + p_v->k = k; > > + p_v->m = m; > > + p_v->p = p; > > + > > + return 0; > > +} > > So. In order to move away from an unmaintainable mess, we create a new > unmaintainable mess? Looks like the way to go. Why is it unmaintainable? This routine should work fine for most Allwinner's SoCs. If it would not for some particular SoC, an other one could be written and called for this case. Maybe are you thinking about the pre/post-divider order. Yes, this routine should enhanced if some rounding problem would be found. > > +const struct clk_ops ccu_pll_ops = { > > + .prepare = ccu_prepare, > > + .unprepare = ccu_unprepare, > > + .enable = ccu_enable, > > + .disable = ccu_disable, > > +/* .is_enabled = NULL; (don't disable the clocks at startup time) */ > > Why? 3 reasons: - as the unused clocks are disabled at system startup time, all the critical clocks should be flagged as such. A problem exists when trying a new SoC: we may not know which clocks are critical, and we stay in front of a black screen when trying to boot. - the clocks may be enabled again when already enabled without any problem. So, it is not important to know if they are already enabled by hardware: the software enable counter is enough. - less code! > > +/* --- mux --- */ > > +static void ccu_mux_adjust_parent_for_prediv(struct ccu *ccu, > > + int parent_index, > > + unsigned long *parent_rate) > > +{ > > + const struct ccu_extra *extra = ccu->extra; > > + int prediv = 1; > > + u32 reg; > > + > > + if (!(extra && > > + (ccu->features & (CCU_FEATURE_MUX_FIXED_PREDIV | > > + CCU_FEATURE_MUX_VARIABLE_PREDIV)))) > > + return; > > + > > + reg = readl(ccu->base + ccu->reg); > > + if (parent_index < 0) > > + parent_index = (reg >> ccu->mux_shift) & > > + ((1 << ccu->mux_width) - 1); > > + > > + if (ccu->features & CCU_FEATURE_MUX_FIXED_PREDIV) > > + prediv = extra->fixed_div[parent_index]; > > + > > + if (ccu->features & CCU_FEATURE_MUX_VARIABLE_PREDIV) > > + if (parent_index == extra->variable_prediv.index) { > > + u8 div; > > + > > + div = reg >> extra->variable_prediv.shift; > > + div &= (1 << extra->variable_prediv.width) - 1; > > + prediv = div + 1; > > + } > > + > > + *parent_rate /= prediv; > > +} > > + > > +/* --- periph --- */ > > +static unsigned long ccu_m_round_rate(struct ccu *ccu, > > + unsigned long rate, > > + unsigned long parent_rate) > > +{ > > + int m; > > + > > + /* > > + * We can't use divider_round_rate that assumes that there's > > + * several parents, while we might be called to evaluate > > + * several different parents. > > + */ > > + m = divider_get_val(rate, parent_rate, > > + ccu->div_table, ccu->m_width, ccu->div_flags); > > + > > + return divider_recalc_rate(&ccu->hw, parent_rate, m, > > + ccu->div_table, ccu->div_flags); > > +} > > + > > +static unsigned long ccu_mp_round_rate(struct ccu *ccu, > > + unsigned long rate, > > + unsigned long parent_rate) > > +{ > > + struct values v; > > + int ret; > > + > > + ret = ccu_pll_find_best(ccu, rate, parent_rate, &v); > > + if (ret) > > + return 0; > > + > > + return parent_rate / v.m >> v.p; > > +} > > + > > +unsigned long ccu_periph_recalc_rate(struct clk_hw *hw, > > + unsigned long parent_rate) > > +{ > > + struct ccu *ccu = hw2ccu(hw); > > + int m, p; > > + u32 reg; > > + > > + ccu_mux_adjust_parent_for_prediv(ccu, -1, &parent_rate); > > + > > + if (!ccu->m_width && !ccu->p_width) > > + return parent_rate; > > + > > + reg = readl(ccu->base + ccu->reg); > > + m = (reg >> ccu->m_shift) & ((1 << ccu->m_width) - 1); > > + > > + if (ccu->p_width) { > > + reg = readl(ccu->base + ccu->reg); > > + p = (reg >> ccu->p_shift) & ((1 << ccu->p_width) - 1); > > + > > + return parent_rate / (m + 1) >> p; > > + } > > + > > + return divider_recalc_rate(hw, parent_rate, m, > > + ccu->div_table, ccu->div_flags); > > +} > > + > > +int ccu_periph_determine_rate(struct clk_hw *hw, > > + struct clk_rate_request *req) > > +{ > > + struct ccu *ccu = hw2ccu(hw); > > + > > + unsigned long best_parent_rate = 0, best_rate = 0; > > + struct clk_hw *best_parent; > > + unsigned int i; > > + unsigned long (*round)(struct ccu *, > > + unsigned long, > > + unsigned long); > > + > > + if (ccu->p_width) > > + round = ccu_mp_round_rate; > > + else if (ccu->m_width) > > + round = ccu_m_round_rate; > > + else > > + return __clk_mux_determine_rate(hw, req); > > + > > + for (i = 0; i < clk_hw_get_num_parents(hw); i++) { > > + unsigned long new_rate, parent_rate; > > + struct clk_hw *parent; > > + > > + parent = clk_hw_get_parent_by_index(hw, i); > > + if (!parent) > > + continue; > > + > > + parent_rate = clk_hw_get_rate(parent); > > + ccu_mux_adjust_parent_for_prediv(ccu, i, &parent_rate); > > + new_rate = round(ccu, req->rate, parent_rate); > > + > > + if (new_rate == req->rate) { > > + best_parent = parent; > > + best_parent_rate = parent_rate; > > + best_rate = new_rate; > > + goto out; > > + } > > + > > + if ((req->rate - new_rate) < (req->rate - best_rate)) { > > + best_rate = new_rate; > > + best_parent_rate = parent_rate; > > + best_parent = parent; > > + } > > + } > > + > > + if (best_rate == 0) > > + return -EINVAL; > > + > > +out: > > + req->best_parent_hw = best_parent; > > + req->best_parent_rate = best_parent_rate; > > + req->rate = best_rate; > > + > > + return 0; > > +} > > Sooo, basically my code. Absolutely. That is told in the header: + * Rewrite from 'sunxi-ng': + * Copyright (C) 2016 Maxime Ripard <maxime.ripard@free-electrons.com> Your code is good, not the structures. > > +int ccu_periph_set_rate(struct clk_hw *hw, unsigned long rate, > > + unsigned long parent_rate) > > +{ > > + struct ccu *ccu = hw2ccu(hw); > > + const struct ccu_extra *extra = ccu->extra; > > + struct values v; > > + u32 mask; > > + int ret; > > + > > + if (!ccu->m_width && !ccu->p_width) > > + return 0; > > + > > + ccu_mux_adjust_parent_for_prediv(ccu, -1, &parent_rate); > > + > > + if (extra && (ccu->features & CCU_FEATURE_MODE_SELECT)) { > > + /* fixme: should use new mode */ > > + if (rate == extra->mode_select.rate) > > + rate /= 2; > > + } > > That needs synchronisation with the MMC driver. How are you dealing > with this? I have problems with the MMCs. I will propose the necessary changes in both the clock and MMC drivers as soon as I have the 3 MMCs working (SDcard, wifi and eMMC) in the Banana Pi M3. > > + > > + if (ccu->p_width) { /* m and p */ > > + ret = ccu_pll_find_best(ccu, rate, parent_rate, &v); > > + if (ret) > > + return ret; > > + } else { /* m alone */ > > + v.m = divider_get_val(rate, parent_rate, > > + ccu->div_table, ccu->m_width, ccu->div_flags); > > + v.p = 0; > > + return 0; > > + } > > + > > + mask = CCU_MASK(ccu->m_shift, ccu->m_width) | > > + CCU_MASK(ccu->p_shift, ccu->p_width); > > + > > + if (ccu->features & CCU_FEATURE_SET_RATE_UNGATE) > > + ccu_disable(hw); > > ungating means enable, and this is already dealt with by the core. Right, the name is wrong. But nothing is done by the core: when CLK_SET_RATE_GATE is set, and when the gate is enabled, set_rate() fails. > > + > > +/* --- fixed factor --- */ > > +/* mul is n_width - div is m_width */ > > +unsigned long ccu_fixed_factor_recalc_rate(struct clk_hw *hw, > > + unsigned long parent_rate) > > +{ > > + struct ccu *ccu = hw2ccu(hw); > > + > > + return parent_rate / ccu->m_width * ccu->n_width; > > +} > > + > > +long ccu_fixed_factor_round_rate(struct clk_hw *hw, > > + unsigned long rate, > > + unsigned long *parent_rate) > > +{ > > + struct ccu *ccu = hw2ccu(hw); > > + > > + if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) { > > + unsigned long best_parent; > > + > > + best_parent = (rate / ccu->n_width) * ccu->m_width; > > + *parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw), > > + best_parent); > > + } > > + > > + return *parent_rate / ccu->m_width * ccu->n_width; > > +} > > + > > +int ccu_fixed_factor_set_rate(struct clk_hw *hw, unsigned long rate, > > + unsigned long parent_rate) > > +{ > > + return 0; > > +} > > + > > +const struct clk_ops ccu_fixed_factor_ops = { > > + .disable = ccu_disable, > > + .enable = ccu_enable, > > +/* .is_enabled = NULL, */ > > + > > + .recalc_rate = ccu_fixed_factor_recalc_rate, > > + .round_rate = ccu_fixed_factor_round_rate, > > + .set_rate = ccu_fixed_factor_set_rate, > > +}; > > This is redundant with the core. I don't see how: - the 'mul' and 'div' fields are not at the same offset - some fixed_factor clocks may have a gate. > > +/* --- reset --- */ > > +static inline > > +struct ccu_reset *rcdev_to_ccu_reset(struct reset_controller_dev *rcdev) > > +{ > > + return container_of(rcdev, struct ccu_reset, rcdev); > > +} > > + > > +static void ccu_set_reset_clock(struct ccu_reset *ccu_reset, > > + int reg, int bit, int enable) > > +{ > > + u32 mask; > > + > > + if (!reg) /* compatibility */ > > + return; > > + > > +#if CCU_DEBUG > > + pr_info("** ccu reset %03x %d %sassert\n", > > + reg, bit, enable ? "de-" : ""); > > +#endif > > You have tracepoints for that. Right. > > + mask = BIT(bit); > > + > > + spin_lock(&ccu_lock); > > + if (enable) > > + writel(readl(ccu_reset->base + reg) | mask, > > + ccu_reset->base + reg); > > + else > > + writel(readl(ccu_reset->base + reg) & ~mask, > > + ccu_reset->base + reg); > > + spin_unlock(&ccu_lock); > > +} > > + > > +static int ccu_reset_assert(struct reset_controller_dev *rcdev, > > + unsigned long id) > > +{ > > + struct ccu_reset *ccu_reset = rcdev_to_ccu_reset(rcdev); > > + const struct ccu_reset_map *map = &ccu_reset->reset_map[id]; > > + > > + ccu_set_reset_clock(ccu_reset, map->reg, map->bit, 0); > > + > > + return 0; > > +} > > + > > +static int ccu_reset_deassert(struct reset_controller_dev *rcdev, > > + unsigned long id) > > +{ > > + struct ccu_reset *ccu_reset = rcdev_to_ccu_reset(rcdev); > > + const struct ccu_reset_map *map = &ccu_reset->reset_map[id]; > > + > > + ccu_set_reset_clock(ccu_reset, map->reg, map->bit, 1); > > + > > + return 0; > > +} > > + > > +const struct reset_control_ops ccu_reset_ops = { > > + .assert = ccu_reset_assert, > > + .deassert = ccu_reset_deassert, > > +}; > > + > > +/* --- init --- */ > > +int __init ccu_probe(struct device_node *node, > > + struct clk_hw_onecell_data *data, > > + struct ccu_reset *resets) > > +{ > > + struct clk_hw *hw; > > + struct ccu *ccu; > > + void __iomem *reg; > > + int i, ret; > > + > > + reg = of_io_request_and_map(node, 0, of_node_full_name(node)); > > + if (IS_ERR(reg)) { > > + pr_err("%s: Clock mapping failed %d\n", > > + of_node_full_name(node), (int) PTR_ERR(reg)); > > + return PTR_ERR(reg); > > + } > > + > > + /* register the clocks */ > > + for (i = 0; i < data->num; i++) { > > + hw = data->hws[i]; > > +#if CCU_DEBUG > > + if (!hw) { > > + pr_err("%s: Bad number of clocks %d != %d\n", > > + of_node_full_name(node), > > + i + 1, data->num); > > + data->num = i; > > + break; > > + } > > +#endif > > + ccu = hw2ccu(hw); > > + ccu->base = reg; > > + ret = clk_hw_register(NULL, hw); > > + if (ret < 0) { > > + pr_err("%s: Register clock %s failed %d\n", > > + of_node_full_name(node), > > + clk_hw_get_name(hw), ret); > > + data->num = i; > > + break; > > + } > > + } > > + ret = of_clk_add_hw_provider(node, of_clk_hw_onecell_get, data); > > + if (ret < 0) > > + goto err; > > + > > + /* register the resets */ > > + resets->rcdev.of_node = node; > > + resets->base = reg; > > + > > + ret = reset_controller_register(&resets->rcdev); > > + if (ret) { > > + pr_err("%s: Reset register failed %d\n", > > + of_node_full_name(node), ret); > > + goto err; > > + } > > + > > + return ret; > > What's the point of this, if we're not using (or exposing for that > matter) any of it? Maybe I was misunderstood: - the control of the reset state may be needed for some clocks or by some drivers, but, - most clocks / drivers don't need it, so, it is possible to hide these resets inside the clock stuff. You may note that some drivers are already prepared to this fact. For example, in the sunxi MMC driver, the reset is optional. - in case a driver requests a reset, this last one should exist. But, this reset may point to a void one (reg = null) when the real reset has been moved to the prepare/unprepare of the associated clock. > > I'm sorry, but the whole point of the initial serie was to rework and > simplify things, precisely because dealing with the clk_factors code > was just too difficult nowadays. And this doesn't solve anything on > that aspect. In my code, all the clock factors I know about are handled. Basically, the requested and the parent rates give a multiplier and a divider. These ones are dispatched into the specific clock factors according to their constraints. If you better like your loops, there is only one place to do the change. > We came with an approach that have all the maintainers involved > agreeing on it, I don't see why we should start over. There's some > useful features there (like tracing). But it's something that can be > added, and should be done differently anyway. OK. I cannot force you.
On Wed, Jun 29, 2016 at 10:12:56AM +0200, Jean-Francois Moine wrote: > On Tue, 28 Jun 2016 22:45:02 +0200 > Maxime Ripard <maxime.ripard@free-electrons.com> wrote: > > > On Tue, Jun 28, 2016 at 05:37:35PM +0200, Jean-Francois Moine wrote: > > > +/* --- prepare / enable --- */ > > > +int ccu_prepare(struct clk_hw *hw) > > > +{ > > > + struct ccu *ccu = hw2ccu(hw); > > > + > > > + if (!ccu->reset_reg && !ccu->bus_reg) > > > + return 0; > > > + > > > +#if CCU_DEBUG > > > + pr_info("** ccu %s prepare\n", clk_hw_get_name(&ccu->hw)); > > > +#endif > > > + spin_lock(&ccu_lock); > > > + if (ccu->reset_reg) > > > + writel(readl(ccu->base + ccu->reset_reg) | > > > + BIT(ccu->reset_bit), > > > + ccu->base + ccu->reset_reg); > > > + if (ccu->bus_reg) > > > + writel(readl(ccu->base + ccu->bus_reg) | BIT(ccu->bus_bit), > > > + ccu->base + ccu->bus_reg); > > > > Like I already said, this is a no-go. > > I don't see why: prepare/unprepare do the right job. This is a huge hack. These clocks and reset lines are doing something different, should and can be enabled at totally different times, have different behaviour that is already relied on by the drivers. So we *need* to expose them as different clocks and reset lines, because they *are* different clocks and reset lines. Plus, I'd like to see the behaviour of that clocks when you call clk_set_rate or clk_set_parent. It's going to be interesting. > > > > + > > > +/* --- PLL --- */ > > > +static int ccu_pll_find_best(struct ccu *ccu, > > > + unsigned long rate, > > > + unsigned long parent_rate, > > > + struct values *p_v) > > > +{ > > > + int max_mul, max_div, mul, div, t; > > > + int n = 1, d1 = 1, k = 1, m = 1, p = 0; > > > + int max_n = 1 << ccu->n_width; > > > + int max_d1 = 1 << ccu->d1_width; > > > + int max_k = 1 << ccu->k_width; > > > + int max_m = 1 << ccu->m_width; > > > + int max_p = 1 << ccu->p_width; > > > + > > > + if (ccu->features & CCU_FEATURE_N0) > > > + max_n--; > > > + > > > + /* compute n */ > > > + if (max_n > 1) { > > > + max_mul = max_n * max_k; > > > + if (rate > parent_rate * max_mul) { > > > + pr_err("%s: Clock rate too high %ld > %ld * %d * %d\n", > > > + clk_hw_get_name(&ccu->hw), > > > + rate, parent_rate, max_n, max_k); > > > + return -EINVAL; > > > + } > > > + max_div = max_m * max_d1 << max_p; > > > + if (max_div > 1) { > > > + unsigned long lmul, ldiv; > > > + > > > + rational_best_approximation(rate, parent_rate, > > > + max_mul - 1, > > > + max_div - 1, > > > + &lmul, &ldiv); > > > + mul = lmul; > > > + div = ldiv; > > > + if (ccu->n_min && mul < ccu->n_min) { > > > + t = (ccu->n_min + mul - 1) / mul; > > > + mul *= t; > > > + div *= t; > > > + } > > > + } else { > > > + mul = (rate + parent_rate - 1) / parent_rate; > > > + div = 1; > > > + } > > > + > > > + /* compute k (present only when 'n' is present) */ > > > + if (max_k > 1) { > > > + int k_min, k_opt, delta_opt = 100, delta; > > > + > > > + k = (mul + max_n - 1) / max_n; > > > + k_opt = k_min = k; > > > + for (k = max_k; k > k_min; k--) { > > > + n = (mul + k - 1) / k; > > > + t = n * k; > > > + delta = t - mul; > > > + if (delta == 0) { > > > + k_opt = k; > > > + break; > > > + } > > > + if (delta < 0) > > > + delta = -delta; > > > + if (delta < delta_opt) { > > > + delta_opt = delta; > > > + k_opt = k; > > > + } > > > + } > > > + k = k_opt; > > > + n = (mul + k - 1) / k; > > > + } else { > > > + n = mul; > > > + } > > > + } else { > > > + div = (parent_rate + rate - 1) / rate; > > > + } > > > + > > > + /* compute d1 (value is only 1 or 2) */ > > > + if (max_d1 > 1) { > > > + if (div % 2 == 0) { > > > + d1 = 2; > > > + div /= 2; > > > + } > > > + } > > > + > > > + /* compute p */ > > > +/* p = 0; */ > > > + while (div % 2 == 0 && p <= max_p) { > > > + p++; > > > + div /= 2; > > > + } > > > + > > > + /* compute m */ > > > + if (max_m > 1) { > > > + if (div <= max_m) > > > + m = div; > > > + else > > > + m = max_m; > > > + div /= m; > > > + } > > > + > > > + /* adjust n */ > > > + n = DIV_ROUND_CLOSEST((rate << p) * m * d1, parent_rate); > > > + n = DIV_ROUND_CLOSEST(n, k); > > > + > > > + p_v->n = n; > > > + p_v->d1 = d1; > > > + p_v->k = k; > > > + p_v->m = m; > > > + p_v->p = p; > > > + > > > + return 0; > > > +} > > > > So. In order to move away from an unmaintainable mess, we create a new > > unmaintainable mess? Looks like the way to go. > > Why is it unmaintainable? This routine should work fine for most > Allwinner's SoCs. Define the algorithm used in three sentences. Maintainability is also about having code that is concise, clear and easy to debug and review. This functions fails in all four. > If it would not for some particular SoC, an other one could be written > and called for this case. The point is to have *common* code. > Maybe are you thinking about the pre/post-divider order. Yes, this > routine should enhanced if some rounding problem would be found. > > > > +const struct clk_ops ccu_pll_ops = { > > > + .prepare = ccu_prepare, > > > + .unprepare = ccu_unprepare, > > > + .enable = ccu_enable, > > > + .disable = ccu_disable, > > > +/* .is_enabled = NULL; (don't disable the clocks at startup time) */ > > > > Why? > > 3 reasons: > > - as the unused clocks are disabled at system startup time, all the > critical clocks should be flagged as such. A problem exists when > trying a new SoC: we may not know which clocks are critical, and > we stay in front of a black screen when trying to boot. Then we find which clock it is, and we flag it as such. That's actually quite easy to do, since the clocks very late in the boot process, way after your UART has been initialised, so this is totally something you can trace. > - the clocks may be enabled again when already enabled without any > problem. Indeed > So, it is not important to know if they are already enabled by > hardware: the software enable counter is enough. It is important to know it if we have some unused clock running, so that we can disable it. And disabling it has a bunch of side effects, most notably saving polar bears, and pointing out clocks that should be flagged as such. > - less code! I fail to see how that's an argument. > > > +int ccu_periph_set_rate(struct clk_hw *hw, unsigned long rate, > > > + unsigned long parent_rate) > > > +{ > > > + struct ccu *ccu = hw2ccu(hw); > > > + const struct ccu_extra *extra = ccu->extra; > > > + struct values v; > > > + u32 mask; > > > + int ret; > > > + > > > + if (!ccu->m_width && !ccu->p_width) > > > + return 0; > > > + > > > + ccu_mux_adjust_parent_for_prediv(ccu, -1, &parent_rate); > > > + > > > + if (extra && (ccu->features & CCU_FEATURE_MODE_SELECT)) { > > > + /* fixme: should use new mode */ > > > + if (rate == extra->mode_select.rate) > > > + rate /= 2; > > > + } > > > > That needs synchronisation with the MMC driver. How are you dealing > > with this? > > I have problems with the MMCs. I will propose the necessary changes in > both the clock and MMC drivers as soon as I have the 3 MMCs working > (SDcard, wifi and eMMC) in the Banana Pi M3. For the time being, that code is broken. And you are using it. > > > + > > > + if (ccu->p_width) { /* m and p */ > > > + ret = ccu_pll_find_best(ccu, rate, parent_rate, &v); > > > + if (ret) > > > + return ret; > > > + } else { /* m alone */ > > > + v.m = divider_get_val(rate, parent_rate, > > > + ccu->div_table, ccu->m_width, ccu->div_flags); > > > + v.p = 0; > > > + return 0; > > > + } > > > + > > > + mask = CCU_MASK(ccu->m_shift, ccu->m_width) | > > > + CCU_MASK(ccu->p_shift, ccu->p_width); > > > + > > > + if (ccu->features & CCU_FEATURE_SET_RATE_UNGATE) > > > + ccu_disable(hw); > > > > ungating means enable, and this is already dealt with by the core. > > Right, the name is wrong. > But nothing is done by the core: when CLK_SET_RATE_GATE is set, and > when the gate is enabled, set_rate() fails. I was talking about CLK_SET_RATE_UNGATE. > > > +const struct clk_ops ccu_fixed_factor_ops = { > > > + .disable = ccu_disable, > > > + .enable = ccu_enable, > > > +/* .is_enabled = NULL, */ > > > + > > > + .recalc_rate = ccu_fixed_factor_recalc_rate, > > > + .round_rate = ccu_fixed_factor_round_rate, > > > + .set_rate = ccu_fixed_factor_set_rate, > > > +}; > > > > This is redundant with the core. > > I don't see how: > - the 'mul' and 'div' fields are not at the same offset > - some fixed_factor clocks may have a gate. Which ones? > > > + mask = BIT(bit); > > > + > > > + spin_lock(&ccu_lock); > > > + if (enable) > > > + writel(readl(ccu_reset->base + reg) | mask, > > > + ccu_reset->base + reg); > > > + else > > > + writel(readl(ccu_reset->base + reg) & ~mask, > > > + ccu_reset->base + reg); > > > + spin_unlock(&ccu_lock); > > > +} > > > + > > > +static int ccu_reset_assert(struct reset_controller_dev *rcdev, > > > + unsigned long id) > > > +{ > > > + struct ccu_reset *ccu_reset = rcdev_to_ccu_reset(rcdev); > > > + const struct ccu_reset_map *map = &ccu_reset->reset_map[id]; > > > + > > > + ccu_set_reset_clock(ccu_reset, map->reg, map->bit, 0); > > > + > > > + return 0; > > > +} > > > + > > > +static int ccu_reset_deassert(struct reset_controller_dev *rcdev, > > > + unsigned long id) > > > +{ > > > + struct ccu_reset *ccu_reset = rcdev_to_ccu_reset(rcdev); > > > + const struct ccu_reset_map *map = &ccu_reset->reset_map[id]; > > > + > > > + ccu_set_reset_clock(ccu_reset, map->reg, map->bit, 1); > > > + > > > + return 0; > > > +} > > > + > > > +const struct reset_control_ops ccu_reset_ops = { > > > + .assert = ccu_reset_assert, > > > + .deassert = ccu_reset_deassert, > > > +}; > > > + > > > +/* --- init --- */ > > > +int __init ccu_probe(struct device_node *node, > > > + struct clk_hw_onecell_data *data, > > > + struct ccu_reset *resets) > > > +{ > > > + struct clk_hw *hw; > > > + struct ccu *ccu; > > > + void __iomem *reg; > > > + int i, ret; > > > + > > > + reg = of_io_request_and_map(node, 0, of_node_full_name(node)); > > > + if (IS_ERR(reg)) { > > > + pr_err("%s: Clock mapping failed %d\n", > > > + of_node_full_name(node), (int) PTR_ERR(reg)); > > > + return PTR_ERR(reg); > > > + } > > > + > > > + /* register the clocks */ > > > + for (i = 0; i < data->num; i++) { > > > + hw = data->hws[i]; > > > +#if CCU_DEBUG > > > + if (!hw) { > > > + pr_err("%s: Bad number of clocks %d != %d\n", > > > + of_node_full_name(node), > > > + i + 1, data->num); > > > + data->num = i; > > > + break; > > > + } > > > +#endif > > > + ccu = hw2ccu(hw); > > > + ccu->base = reg; > > > + ret = clk_hw_register(NULL, hw); > > > + if (ret < 0) { > > > + pr_err("%s: Register clock %s failed %d\n", > > > + of_node_full_name(node), > > > + clk_hw_get_name(hw), ret); > > > + data->num = i; > > > + break; > > > + } > > > + } > > > + ret = of_clk_add_hw_provider(node, of_clk_hw_onecell_get, data); > > > + if (ret < 0) > > > + goto err; > > > + > > > + /* register the resets */ > > > + resets->rcdev.of_node = node; > > > + resets->base = reg; > > > + > > > + ret = reset_controller_register(&resets->rcdev); > > > + if (ret) { > > > + pr_err("%s: Reset register failed %d\n", > > > + of_node_full_name(node), ret); > > > + goto err; > > > + } > > > + > > > + return ret; > > > > What's the point of this, if we're not using (or exposing for that > > matter) any of it? > > Maybe I was misunderstood: > - the control of the reset state may be needed for some clocks or by > some drivers, but, > - most clocks / drivers don't need it, so, it is possible to hide these > resets inside the clock stuff. You may note that some drivers are > already prepared to this fact. For example, in the sunxi MMC driver, > the reset is optional. Because you don't have a reset line on the first SoCs. This has nothing to do with our discussion. > - in case a driver requests a reset, this last one should exist. > But, this reset may point to a void one (reg = null) when the real > reset has been moved to the prepare/unprepare of the associated clock. And what if this driver wants to be reset, by calling reset_control_reset? You realize you're going against the semantics of the reset and clock APIs, and what the hardware expose here right? > > I'm sorry, but the whole point of the initial serie was to rework and > > simplify things, precisely because dealing with the clk_factors code > > was just too difficult nowadays. And this doesn't solve anything on > > that aspect. > > In my code, all the clock factors I know about are handled. > Basically, the requested and the parent rates give a multiplier and a > divider. These ones are dispatched into the specific clock factors > according to their constraints. You missed the "simplify" part. The other reason for this serie to exist was to be consistent with what the other architectures are doing, which is not the case here either. Maxime
On Thu, 30 Jun 2016 23:16:35 +0200 Maxime Ripard <maxime.ripard@free-electrons.com> wrote: > > - some fixed_factor clocks may have a gate. > > Which ones? I know only the "osc12M" in the A83T. It is used by the ehci1.
On Thu, 30 Jun 2016 23:16:35 +0200 Maxime Ripard <maxime.ripard@free-electrons.com> wrote: > > - in case a driver requests a reset, this last one should exist. > > But, this reset may point to a void one (reg = null) when the real > > reset has been moved to the prepare/unprepare of the associated clock. > > And what if this driver wants to be reset, by calling > reset_control_reset? You realize you're going against the semantics of > the reset and clock APIs, and what the hardware expose here right? If a driver really wants a reset, the reset stuff is not included in the clock prepare.
On Thu, 30 Jun 2016 23:16:35 +0200 Maxime Ripard <maxime.ripard@free-electrons.com> wrote: > > > I'm sorry, but the whole point of the initial serie was to rework and > > > simplify things, precisely because dealing with the clk_factors code > > > was just too difficult nowadays. And this doesn't solve anything on > > > that aspect. > > > > In my code, all the clock factors I know about are handled. > > Basically, the requested and the parent rates give a multiplier and a > > divider. These ones are dispatched into the specific clock factors > > according to their constraints. > > You missed the "simplify" part. The other reason for this serie to > exist was to be consistent with what the other architectures are > doing, which is not the case here either. The other architectures have not a so complex mechanism as Allwinner's. The 'divider'/'fractional-divider'/multiplier'/... "standard" functions cannot be used in ou case. Your 'sunxi-ng' just add new structures to replace them, and, in fact, you are building an other restricted composite clock system. which will be unusable when new SoCs will appear. Yes, I should not have include the reset/bus gate/factor computation stuff in my patch series. Because the only important part is to have a flat definition of all the parameters giving this more simplification: one structure and one source file.
diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile index 39d2044..b8ca3e2 100644 --- a/drivers/clk/sunxi/Makefile +++ b/drivers/clk/sunxi/Makefile @@ -26,3 +26,5 @@ obj-$(CONFIG_MACH_SUN9I) += clk-sun9i-cpus.o obj-$(CONFIG_MFD_SUN6I_PRCM) += \ clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o \ clk-sun8i-apb0.o + +obj-y += ccu.o diff --git a/drivers/clk/sunxi/ccu.c b/drivers/clk/sunxi/ccu.c new file mode 100644 index 0000000..5749f9c --- /dev/null +++ b/drivers/clk/sunxi/ccu.c @@ -0,0 +1,980 @@ +/* + * Allwinner system CCU + * + * Copyright (C) 2016 Jean-Francois Moine <moinejf@free.fr> + * Rewrite from 'sunxi-ng': + * Copyright (C) 2016 Maxime Ripard <maxime.ripard@free-electrons.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + */ + +#include <linux/clk-provider.h> +#include <linux/reset-controller.h> +#include <linux/iopoll.h> +#include <linux/slab.h> +#include <linux/rational.h> +#include <linux/of_address.h> + +#include "ccu.h" + +#define CCU_DEBUG 0 + +#define CCU_MASK(shift, width) (((1 << width) - 1) << shift) + +/* + * factors: + * n: multiplier (PLL) + * d1, d2: boolean dividers by 2 (d2 is p with 1 bit width - PLL) + * k: multiplier (PLL) + * m: divider + * p: divider by power of 2 + */ +struct values { + int n, d1, k, m, p; +}; + +static DEFINE_SPINLOCK(ccu_lock); + +void ccu_set_clock(struct ccu *ccu, int reg, u32 mask, u32 val) +{ + +#if CCU_DEBUG + pr_info("** ccu %s set %03x %08x\n", + clk_hw_get_name(&ccu->hw), reg, + (readl(ccu->base + reg) & ~mask) | val); +#endif + spin_lock(&ccu_lock); + writel((readl(ccu->base + reg) & ~mask) | val, ccu->base + reg); + spin_unlock(&ccu_lock); +} + +/* --- prepare / enable --- */ +int ccu_prepare(struct clk_hw *hw) +{ + struct ccu *ccu = hw2ccu(hw); + + if (!ccu->reset_reg && !ccu->bus_reg) + return 0; + +#if CCU_DEBUG + pr_info("** ccu %s prepare\n", clk_hw_get_name(&ccu->hw)); +#endif + spin_lock(&ccu_lock); + if (ccu->reset_reg) + writel(readl(ccu->base + ccu->reset_reg) | + BIT(ccu->reset_bit), + ccu->base + ccu->reset_reg); + if (ccu->bus_reg) + writel(readl(ccu->base + ccu->bus_reg) | BIT(ccu->bus_bit), + ccu->base + ccu->bus_reg); + spin_unlock(&ccu_lock); + + return 0; +} + +void ccu_unprepare(struct clk_hw *hw) +{ + struct ccu *ccu = hw2ccu(hw); + + if (!ccu->reset_reg && !ccu->bus_reg) + return; + +#if CCU_DEBUG + pr_info("** ccu %s unprepare\n", clk_hw_get_name(&ccu->hw)); +#endif + spin_lock(&ccu_lock); + if (ccu->bus_reg) + writel(readl(ccu->base + ccu->bus_reg) & ~BIT(ccu->bus_bit), + ccu->base + ccu->bus_reg); + if (ccu->reset_reg) + writel(readl(ccu->base + ccu->reset_reg) & + ~BIT(ccu->reset_bit), + ccu->base + ccu->reset_reg); + spin_unlock(&ccu_lock); +} + +int ccu_enable(struct clk_hw *hw) +{ + struct ccu *ccu = hw2ccu(hw); + + if (!ccu->has_gate) + return 0; + +#if CCU_DEBUG + pr_info("** ccu %s enable\n", clk_hw_get_name(&ccu->hw)); +#endif + spin_lock(&ccu_lock); + writel(readl(ccu->base + ccu->reg) | BIT(ccu->gate_bit), + ccu->base + ccu->reg); + spin_unlock(&ccu_lock); + + return 0; +} + +void ccu_disable(struct clk_hw *hw) +{ + struct ccu *ccu = hw2ccu(hw); + + if (!ccu->has_gate) + return; + +#if CCU_DEBUG + pr_info("** ccu %s disable\n", clk_hw_get_name(&ccu->hw)); +#endif + spin_lock(&ccu_lock); + writel(readl(ccu->base + ccu->reg) & ~BIT(ccu->gate_bit), + ccu->base + ccu->reg); + spin_unlock(&ccu_lock); +} + +/* --- PLL --- */ +static int ccu_pll_find_best(struct ccu *ccu, + unsigned long rate, + unsigned long parent_rate, + struct values *p_v) +{ + int max_mul, max_div, mul, div, t; + int n = 1, d1 = 1, k = 1, m = 1, p = 0; + int max_n = 1 << ccu->n_width; + int max_d1 = 1 << ccu->d1_width; + int max_k = 1 << ccu->k_width; + int max_m = 1 << ccu->m_width; + int max_p = 1 << ccu->p_width; + + if (ccu->features & CCU_FEATURE_N0) + max_n--; + + /* compute n */ + if (max_n > 1) { + max_mul = max_n * max_k; + if (rate > parent_rate * max_mul) { + pr_err("%s: Clock rate too high %ld > %ld * %d * %d\n", + clk_hw_get_name(&ccu->hw), + rate, parent_rate, max_n, max_k); + return -EINVAL; + } + max_div = max_m * max_d1 << max_p; + if (max_div > 1) { + unsigned long lmul, ldiv; + + rational_best_approximation(rate, parent_rate, + max_mul - 1, + max_div - 1, + &lmul, &ldiv); + mul = lmul; + div = ldiv; + if (ccu->n_min && mul < ccu->n_min) { + t = (ccu->n_min + mul - 1) / mul; + mul *= t; + div *= t; + } + } else { + mul = (rate + parent_rate - 1) / parent_rate; + div = 1; + } + + /* compute k (present only when 'n' is present) */ + if (max_k > 1) { + int k_min, k_opt, delta_opt = 100, delta; + + k = (mul + max_n - 1) / max_n; + k_opt = k_min = k; + for (k = max_k; k > k_min; k--) { + n = (mul + k - 1) / k; + t = n * k; + delta = t - mul; + if (delta == 0) { + k_opt = k; + break; + } + if (delta < 0) + delta = -delta; + if (delta < delta_opt) { + delta_opt = delta; + k_opt = k; + } + } + k = k_opt; + n = (mul + k - 1) / k; + } else { + n = mul; + } + } else { + div = (parent_rate + rate - 1) / rate; + } + + /* compute d1 (value is only 1 or 2) */ + if (max_d1 > 1) { + if (div % 2 == 0) { + d1 = 2; + div /= 2; + } + } + + /* compute p */ +/* p = 0; */ + while (div % 2 == 0 && p <= max_p) { + p++; + div /= 2; + } + + /* compute m */ + if (max_m > 1) { + if (div <= max_m) + m = div; + else + m = max_m; + div /= m; + } + + /* adjust n */ + n = DIV_ROUND_CLOSEST((rate << p) * m * d1, parent_rate); + n = DIV_ROUND_CLOSEST(n, k); + + p_v->n = n; + p_v->d1 = d1; + p_v->k = k; + p_v->m = m; + p_v->p = p; + + return 0; +} + +static unsigned long ccu_pll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct ccu *ccu = hw2ccu(hw); + const struct ccu_extra *extra = ccu->extra; + unsigned long rate; + int i, n, d1, m, k, p; + u32 reg; + + reg = readl(ccu->base + ccu->reg); + + if (extra) { + for (i = 0; i < extra->num_frac - 1; i++) { + if ((reg & extra->frac[i].mask) == extra->frac[i].val) + return rate = extra->frac[i].rate; + } + } + + rate = parent_rate; + + if (ccu->d1_width) { + d1 = reg >> ccu->d1_shift; + d1 &= (1 << ccu->d1_width) - 1; + rate /= (d1 + 1); + } + + if (ccu->n_width) { + n = reg >> ccu->n_shift; + n &= (1 << ccu->n_width) - 1; + if (!(ccu->features & CCU_FEATURE_N0)) + n++; + rate *= n; + } + + if (ccu->m_width) { + m = reg >> ccu->m_shift; + m &= (1 << ccu->m_width) - 1; + rate /= (m + 1); + } + + if (ccu->k_width) { + k = reg >> ccu->k_shift; + k &= (1 << ccu->k_width) - 1; + rate *= (k + 1); + } + + if (ccu->p_width) { + p = reg >> ccu->p_shift; + p &= (1 << ccu->p_width) - 1; + rate >>= p; + } + + if (extra && (ccu->features & CCU_FEATURE_FIXED_POSTDIV)) + rate /= extra->fixed_div[0]; + + return rate; +} + +static long ccu_pll_round_rate(struct clk_hw *hw, + unsigned long rate, + unsigned long *parent_rate) +{ + struct ccu *ccu = hw2ccu(hw); + const struct ccu_extra *extra = ccu->extra; + struct values v; + int i, ret; + + if (extra) { + for (i = 0; i < extra->num_frac - 1; i++) { + if (extra->frac[i].rate == rate) + return rate; + } + + if (ccu->features & CCU_FEATURE_FIXED_POSTDIV) + rate *= extra->fixed_div[0]; + } + + ret = ccu_pll_find_best(ccu, rate, *parent_rate, &v); + if (ret) + return ret; + + rate = *parent_rate / v.d1 * v.n / v.m * v.k >> v.p; + + if (extra && (ccu->features & CCU_FEATURE_FIXED_POSTDIV)) + rate /= extra->fixed_div[0]; + + return rate; +} + +static void ccu_pll_set_flat_factors(struct ccu *ccu, u32 mask, u32 val) +{ + u32 reg, m_val, p_val; + u32 m_mask = (1 << ccu->m_width) - 1; + u32 p_mask = (1 << ccu->p_width) - 1; + + reg = readl(ccu->base + ccu->reg); + m_val = reg & m_mask; + p_val = reg & p_mask; + + spin_lock(&ccu_lock); + + /* increase p, then m */ + if (ccu->p_width && p_val < (val & p_mask)) { + reg &= ~p_mask; + reg |= val & p_mask; + writel(reg, ccu->base + ccu->reg); + udelay(10); + } + if (ccu->m_width && m_val < (val & m_mask)) { + reg &= ~m_mask; + reg |= val & m_mask; + writel(reg, ccu->base + ccu->reg); + udelay(10); + } + + /* set other factors */ + reg &= ~(mask & ~(p_mask | m_mask)); + reg |= val & ~(p_mask | m_mask); + writel(reg, ccu->base + ccu->reg); + + /* decrease m */ + if (ccu->m_width && m_val > (val & m_mask)) { + reg &= ~m_mask; + reg |= val & m_mask; + writel(reg, ccu->base + ccu->reg); + udelay(10); + } + + /* wait for PLL stable */ + if (ccu->lock_reg) { + u32 lock; + + lock = BIT(ccu->lock_bit); + WARN_ON(readl_relaxed_poll_timeout(ccu->base + ccu->lock_reg, + reg, !(reg & lock), + 100, 70000)); + } + + /* decrease p */ + if (ccu->p_width && p_val > (val & p_mask)) { + reg &= ~p_mask; + reg |= val & p_mask; + writel(reg, ccu->base + ccu->reg); + udelay(10); + } + + spin_unlock(&ccu_lock); +} + +static int ccu_pll_set_rate(struct clk_hw *hw, + unsigned long rate, + unsigned long parent_rate) +{ + struct ccu *ccu = hw2ccu(hw); + const struct ccu_extra *extra = ccu->extra; + struct values v; + u32 mask, val; + int ret; + + mask = CCU_MASK(ccu->n_shift, ccu->n_width) | + CCU_MASK(ccu->d1_shift, ccu->d1_width) | + CCU_MASK(ccu->k_shift, ccu->k_width) | + CCU_MASK(ccu->m_shift, ccu->m_width) | + CCU_MASK(ccu->p_shift, ccu->p_width); + val = 0; + + if (extra && extra->num_frac) { + int i; + + for (i = 0; i < extra->num_frac - 1; i++) { + if (extra->frac[i].rate == rate) { + ccu_set_clock(ccu, ccu->reg, + extra->frac[i].mask, + extra->frac[i].val); + return 0; + } + } + mask |= extra->frac[i].mask; + val |= extra->frac[i].val; + } + + if (extra && (ccu->features & CCU_FEATURE_FIXED_POSTDIV)) + rate *= extra->fixed_div[0]; + + + ret = ccu_pll_find_best(ccu, rate, parent_rate, &v); + if (ret) + return ret; + + if (!(ccu->features & CCU_FEATURE_N0)) + v.n--; + + val |= (v.n << ccu->n_shift) | + ((v.d1 - 1) << ccu->d1_shift) | + ((v.k - 1) << ccu->k_shift) | + ((v.m - 1) << ccu->m_shift) | + (v.p << ccu->p_shift); + + if (ccu->upd_bit) /* cannot be 0 */ + val |= BIT(ccu->upd_bit); + + if (!(ccu->features & CCU_FEATURE_FLAT_FACTORS)) + ccu_set_clock(ccu, ccu->reg, mask, val); + else + ccu_pll_set_flat_factors(ccu, mask, val); + + /* wait for PLL stable */ + if (ccu->lock_reg) { + u32 lock, reg; + + lock = BIT(ccu->lock_bit); + WARN_ON(readl_relaxed_poll_timeout(ccu->base + ccu->lock_reg, + reg, !(reg & lock), + 100, 70000)); + } + + return 0; +} + +const struct clk_ops ccu_pll_ops = { + .prepare = ccu_prepare, + .unprepare = ccu_unprepare, + .enable = ccu_enable, + .disable = ccu_disable, +/* .is_enabled = NULL; (don't disable the clocks at startup time) */ + + .recalc_rate = ccu_pll_recalc_rate, + .round_rate = ccu_pll_round_rate, + .set_rate = ccu_pll_set_rate, +}; + +/* --- mux parent --- */ +u8 ccu_get_parent(struct clk_hw *hw) +{ + struct ccu *ccu = hw2ccu(hw); + + if (!ccu->mux_width) + return 0; + + return (readl(ccu->base + ccu->reg) >> ccu->mux_shift) & + ((1 << ccu->mux_width) - 1); +} + +int ccu_set_parent(struct clk_hw *hw, u8 index) +{ + struct ccu *ccu = hw2ccu(hw); + u32 mask; + + if (!ccu->mux_width) + return 0; + + mask = CCU_MASK(ccu->mux_shift, ccu->mux_width); + + ccu_set_clock(ccu, ccu->reg, mask, index << ccu->mux_shift); + + return 0; +} + +/* --- mux --- */ +static void ccu_mux_adjust_parent_for_prediv(struct ccu *ccu, + int parent_index, + unsigned long *parent_rate) +{ + const struct ccu_extra *extra = ccu->extra; + int prediv = 1; + u32 reg; + + if (!(extra && + (ccu->features & (CCU_FEATURE_MUX_FIXED_PREDIV | + CCU_FEATURE_MUX_VARIABLE_PREDIV)))) + return; + + reg = readl(ccu->base + ccu->reg); + if (parent_index < 0) + parent_index = (reg >> ccu->mux_shift) & + ((1 << ccu->mux_width) - 1); + + if (ccu->features & CCU_FEATURE_MUX_FIXED_PREDIV) + prediv = extra->fixed_div[parent_index]; + + if (ccu->features & CCU_FEATURE_MUX_VARIABLE_PREDIV) + if (parent_index == extra->variable_prediv.index) { + u8 div; + + div = reg >> extra->variable_prediv.shift; + div &= (1 << extra->variable_prediv.width) - 1; + prediv = div + 1; + } + + *parent_rate /= prediv; +} + +/* --- periph --- */ +static unsigned long ccu_m_round_rate(struct ccu *ccu, + unsigned long rate, + unsigned long parent_rate) +{ + int m; + + /* + * We can't use divider_round_rate that assumes that there's + * several parents, while we might be called to evaluate + * several different parents. + */ + m = divider_get_val(rate, parent_rate, + ccu->div_table, ccu->m_width, ccu->div_flags); + + return divider_recalc_rate(&ccu->hw, parent_rate, m, + ccu->div_table, ccu->div_flags); +} + +static unsigned long ccu_mp_round_rate(struct ccu *ccu, + unsigned long rate, + unsigned long parent_rate) +{ + struct values v; + int ret; + + ret = ccu_pll_find_best(ccu, rate, parent_rate, &v); + if (ret) + return 0; + + return parent_rate / v.m >> v.p; +} + +unsigned long ccu_periph_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct ccu *ccu = hw2ccu(hw); + int m, p; + u32 reg; + + ccu_mux_adjust_parent_for_prediv(ccu, -1, &parent_rate); + + if (!ccu->m_width && !ccu->p_width) + return parent_rate; + + reg = readl(ccu->base + ccu->reg); + m = (reg >> ccu->m_shift) & ((1 << ccu->m_width) - 1); + + if (ccu->p_width) { + reg = readl(ccu->base + ccu->reg); + p = (reg >> ccu->p_shift) & ((1 << ccu->p_width) - 1); + + return parent_rate / (m + 1) >> p; + } + + return divider_recalc_rate(hw, parent_rate, m, + ccu->div_table, ccu->div_flags); +} + +int ccu_periph_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) +{ + struct ccu *ccu = hw2ccu(hw); + + unsigned long best_parent_rate = 0, best_rate = 0; + struct clk_hw *best_parent; + unsigned int i; + unsigned long (*round)(struct ccu *, + unsigned long, + unsigned long); + + if (ccu->p_width) + round = ccu_mp_round_rate; + else if (ccu->m_width) + round = ccu_m_round_rate; + else + return __clk_mux_determine_rate(hw, req); + + for (i = 0; i < clk_hw_get_num_parents(hw); i++) { + unsigned long new_rate, parent_rate; + struct clk_hw *parent; + + parent = clk_hw_get_parent_by_index(hw, i); + if (!parent) + continue; + + parent_rate = clk_hw_get_rate(parent); + ccu_mux_adjust_parent_for_prediv(ccu, i, &parent_rate); + new_rate = round(ccu, req->rate, parent_rate); + + if (new_rate == req->rate) { + best_parent = parent; + best_parent_rate = parent_rate; + best_rate = new_rate; + goto out; + } + + if ((req->rate - new_rate) < (req->rate - best_rate)) { + best_rate = new_rate; + best_parent_rate = parent_rate; + best_parent = parent; + } + } + + if (best_rate == 0) + return -EINVAL; + +out: + req->best_parent_hw = best_parent; + req->best_parent_rate = best_parent_rate; + req->rate = best_rate; + + return 0; +} + +int ccu_periph_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct ccu *ccu = hw2ccu(hw); + const struct ccu_extra *extra = ccu->extra; + struct values v; + u32 mask; + int ret; + + if (!ccu->m_width && !ccu->p_width) + return 0; + + ccu_mux_adjust_parent_for_prediv(ccu, -1, &parent_rate); + + if (extra && (ccu->features & CCU_FEATURE_MODE_SELECT)) { + /* fixme: should use new mode */ + if (rate == extra->mode_select.rate) + rate /= 2; + } + + if (ccu->p_width) { /* m and p */ + ret = ccu_pll_find_best(ccu, rate, parent_rate, &v); + if (ret) + return ret; + } else { /* m alone */ + v.m = divider_get_val(rate, parent_rate, + ccu->div_table, ccu->m_width, ccu->div_flags); + v.p = 0; + return 0; + } + + mask = CCU_MASK(ccu->m_shift, ccu->m_width) | + CCU_MASK(ccu->p_shift, ccu->p_width); + + if (ccu->features & CCU_FEATURE_SET_RATE_UNGATE) + ccu_disable(hw); + ccu_set_clock(ccu, ccu->reg, mask, ((v.m - 1) << ccu->m_shift) | + (v.p << ccu->p_shift)); + if (ccu->features & CCU_FEATURE_SET_RATE_UNGATE) + ccu_enable(hw); + + return 0; +} + +const struct clk_ops ccu_periph_ops = { + .prepare = ccu_prepare, + .unprepare = ccu_unprepare, + .enable = ccu_enable, + .disable = ccu_disable, +/* .is_enabled = NULL; (don't disable the clocks at startup time) */ + + .get_parent = ccu_get_parent, + .set_parent = ccu_set_parent, + + .determine_rate = ccu_periph_determine_rate, + .recalc_rate = ccu_periph_recalc_rate, + .set_rate = ccu_periph_set_rate, +}; + +/* --- fixed factor --- */ +/* mul is n_width - div is m_width */ +unsigned long ccu_fixed_factor_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct ccu *ccu = hw2ccu(hw); + + return parent_rate / ccu->m_width * ccu->n_width; +} + +long ccu_fixed_factor_round_rate(struct clk_hw *hw, + unsigned long rate, + unsigned long *parent_rate) +{ + struct ccu *ccu = hw2ccu(hw); + + if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) { + unsigned long best_parent; + + best_parent = (rate / ccu->n_width) * ccu->m_width; + *parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw), + best_parent); + } + + return *parent_rate / ccu->m_width * ccu->n_width; +} + +int ccu_fixed_factor_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + return 0; +} + +const struct clk_ops ccu_fixed_factor_ops = { + .disable = ccu_disable, + .enable = ccu_enable, +/* .is_enabled = NULL, */ + + .recalc_rate = ccu_fixed_factor_recalc_rate, + .round_rate = ccu_fixed_factor_round_rate, + .set_rate = ccu_fixed_factor_set_rate, +}; + +/* --- phase --- */ +static int ccu_phase_get_phase(struct clk_hw *hw) +{ + struct ccu *ccu = hw2ccu(hw); + struct clk_hw *parent, *grandparent; + unsigned int parent_rate, grandparent_rate; + u16 step, parent_div; + u32 reg; + u8 delay; + + reg = readl(ccu->base + ccu->reg); + delay = (reg >> ccu->p_shift); + delay &= (1 << ccu->p_width) - 1; + + if (!delay) + return 180; + + /* Get our parent clock, it's the one that can adjust its rate */ + parent = clk_hw_get_parent(hw); + if (!parent) + return -EINVAL; + + /* And its rate */ + parent_rate = clk_hw_get_rate(parent); + if (!parent_rate) + return -EINVAL; + + /* Now, get our parent's parent (most likely some PLL) */ + grandparent = clk_hw_get_parent(parent); + if (!grandparent) + return -EINVAL; + + /* And its rate */ + grandparent_rate = clk_hw_get_rate(grandparent); + if (!grandparent_rate) + return -EINVAL; + + /* Get our parent clock divider */ + parent_div = grandparent_rate / parent_rate; + + step = DIV_ROUND_CLOSEST(360, parent_div); + return delay * step; +} + +static int ccu_phase_set_phase(struct clk_hw *hw, int degrees) +{ + struct ccu *ccu = hw2ccu(hw); + struct clk_hw *parent, *grandparent; + unsigned int parent_rate, grandparent_rate; + u32 mask; + u8 delay = 0; + u16 step, parent_div; + + if (degrees == 180) + goto set_phase; + + /* Get our parent clock, it's the one that can adjust its rate */ + parent = clk_hw_get_parent(hw); + if (!parent) + return -EINVAL; + + /* And its rate */ + parent_rate = clk_hw_get_rate(parent); + if (!parent_rate) + return -EINVAL; + + /* Now, get our parent's parent (most likely some PLL) */ + grandparent = clk_hw_get_parent(parent); + if (!grandparent) + return -EINVAL; + + /* And its rate */ + grandparent_rate = clk_hw_get_rate(grandparent); + if (!grandparent_rate) + return -EINVAL; + + /* Get our parent divider */ + parent_div = grandparent_rate / parent_rate; + + /* + * We can only outphase the clocks by multiple of the + * PLL's period. + * + * Since our parent clock is only a divider, and the + * formula to get the outphasing in degrees is deg = + * 360 * delta / period + * + * If we simplify this formula, we can see that the + * only thing that we're concerned about is the number + * of period we want to outphase our clock from, and + * the divider set by our parent clock. + */ + step = DIV_ROUND_CLOSEST(360, parent_div); + delay = DIV_ROUND_CLOSEST(degrees, step); + +set_phase: + mask = CCU_MASK(ccu->p_shift, ccu->p_width); + ccu_set_clock(ccu, ccu->reg, mask, delay << ccu->p_shift); + + return 0; +} + +const struct clk_ops ccu_phase_ops = { + .get_phase = ccu_phase_get_phase, + .set_phase = ccu_phase_set_phase, +}; + +/* --- reset --- */ +static inline +struct ccu_reset *rcdev_to_ccu_reset(struct reset_controller_dev *rcdev) +{ + return container_of(rcdev, struct ccu_reset, rcdev); +} + +static void ccu_set_reset_clock(struct ccu_reset *ccu_reset, + int reg, int bit, int enable) +{ + u32 mask; + + if (!reg) /* compatibility */ + return; + +#if CCU_DEBUG + pr_info("** ccu reset %03x %d %sassert\n", + reg, bit, enable ? "de-" : ""); +#endif + mask = BIT(bit); + + spin_lock(&ccu_lock); + if (enable) + writel(readl(ccu_reset->base + reg) | mask, + ccu_reset->base + reg); + else + writel(readl(ccu_reset->base + reg) & ~mask, + ccu_reset->base + reg); + spin_unlock(&ccu_lock); +} + +static int ccu_reset_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct ccu_reset *ccu_reset = rcdev_to_ccu_reset(rcdev); + const struct ccu_reset_map *map = &ccu_reset->reset_map[id]; + + ccu_set_reset_clock(ccu_reset, map->reg, map->bit, 0); + + return 0; +} + +static int ccu_reset_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct ccu_reset *ccu_reset = rcdev_to_ccu_reset(rcdev); + const struct ccu_reset_map *map = &ccu_reset->reset_map[id]; + + ccu_set_reset_clock(ccu_reset, map->reg, map->bit, 1); + + return 0; +} + +const struct reset_control_ops ccu_reset_ops = { + .assert = ccu_reset_assert, + .deassert = ccu_reset_deassert, +}; + +/* --- init --- */ +int __init ccu_probe(struct device_node *node, + struct clk_hw_onecell_data *data, + struct ccu_reset *resets) +{ + struct clk_hw *hw; + struct ccu *ccu; + void __iomem *reg; + int i, ret; + + reg = of_io_request_and_map(node, 0, of_node_full_name(node)); + if (IS_ERR(reg)) { + pr_err("%s: Clock mapping failed %d\n", + of_node_full_name(node), (int) PTR_ERR(reg)); + return PTR_ERR(reg); + } + + /* register the clocks */ + for (i = 0; i < data->num; i++) { + hw = data->hws[i]; +#if CCU_DEBUG + if (!hw) { + pr_err("%s: Bad number of clocks %d != %d\n", + of_node_full_name(node), + i + 1, data->num); + data->num = i; + break; + } +#endif + ccu = hw2ccu(hw); + ccu->base = reg; + ret = clk_hw_register(NULL, hw); + if (ret < 0) { + pr_err("%s: Register clock %s failed %d\n", + of_node_full_name(node), + clk_hw_get_name(hw), ret); + data->num = i; + break; + } + } + ret = of_clk_add_hw_provider(node, of_clk_hw_onecell_get, data); + if (ret < 0) + goto err; + + /* register the resets */ + resets->rcdev.of_node = node; + resets->base = reg; + + ret = reset_controller_register(&resets->rcdev); + if (ret) { + pr_err("%s: Reset register failed %d\n", + of_node_full_name(node), ret); + goto err; + } + + return ret; + +err: + /* don't do anything, otherwise no uart anymore */ + return ret; +} diff --git a/drivers/clk/sunxi/ccu.h b/drivers/clk/sunxi/ccu.h new file mode 100644 index 0000000..5597681 --- /dev/null +++ b/drivers/clk/sunxi/ccu.h @@ -0,0 +1,153 @@ +/* + * Copyright (C) 2016 Jean-Francois Moine <moinejf@free.fr> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + */ + +#ifndef _CCU_H_ +#define _CCU_H_ + +struct device_node; + +#define CCU_HW(_name, _parent, _ops, _flags) \ + .hw.init = &(struct clk_init_data) { \ + .flags = _flags, \ + .name = _name, \ + .parent_names = (const char *[]) { _parent }, \ + .num_parents = 1, \ + .ops = _ops, \ + } + +#define CCU_HW_PARENTS(_name, _parents, _ops, _flags) \ + .hw.init = &(struct clk_init_data) { \ + .flags = _flags, \ + .name = _name, \ + .parent_names = _parents, \ + .num_parents = ARRAY_SIZE(_parents), \ + .ops = _ops, \ + } + +#define CCU_REG(_reg) .reg = _reg +#define CCU_RESET(_reg, _bit) .reset_reg = _reg, .reset_bit = _bit +#define CCU_BUS(_reg, _bit) .bus_reg = _reg, .bus_bit = _bit +#define CCU_GATE(_bit) .has_gate = 1, .gate_bit = _bit +#define CCU_LOCK(_reg, _bit) .lock_reg = _reg, .lock_bit = _bit +#define CCU_MUX(_shift, _width) .mux_shift = _shift, .mux_width = _width +#define CCU_N(_shift, _width) .n_shift = _shift, .n_width = _width +#define CCU_D1(_shift, _width) .d1_shift = _shift, .d1_width = _width +#define CCU_D2(_shift, _width) .p_shift = _shift, .p_width = _width +#define CCU_K(_shift, _width) .k_shift = _shift, .k_width = _width +#define CCU_M(_shift, _width) .m_shift = _shift, .m_width = _width +#define CCU_P(_shift, _width) .p_shift = _shift, .p_width = _width +#define CCU_UPD(_bit) .upd_bit = _bit +/* with ccu_fixed_factor_ops */ +#define CCU_FIXED(_mul, _div) .n_width = _mul, .m_width = _div +/* with ccu_phase_ops */ +#define CCU_PHASE(_shift, _width) .p_shift = _shift, .p_width = _width + +#define CCU_FEATURE_FRACTIONAL BIT(0) +#define CCU_FEATURE_MUX_VARIABLE_PREDIV BIT(1) +#define CCU_FEATURE_MUX_FIXED_PREDIV BIT(2) +#define CCU_FEATURE_FIXED_POSTDIV BIT(3) +#define CCU_FEATURE_N0 BIT(4) +#define CCU_FEATURE_MODE_SELECT BIT(5) +#define CCU_FEATURE_FLAT_FACTORS BIT(6) +#define CCU_FEATURE_SET_RATE_UNGATE BIT(7) + +/* extra */ +#define CCU_EXTRA_FRAC(_frac) .frac = _frac, .num_frac = ARRAY_SIZE(_frac) +#define CCU_EXTRA_POST_DIV(_div) .fixed_div[0] = _div + +/* fractional values */ +struct frac { + unsigned long rate; + u32 mask; + u32 val; +}; + +/* extra features */ +struct ccu_extra { + const struct frac *frac; /* array - last is the fractional mask/value */ + u8 num_frac; + + u8 fixed_div[4]; + + struct { + u8 index; + u8 shift; + u8 width; + } variable_prediv; + + struct { + unsigned long rate; + u8 bit; + } mode_select; +}; + +struct ccu { + struct clk_hw hw; + + void __iomem *base; + u16 reg; + + u16 reset_reg, bus_reg, lock_reg; + u8 reset_bit, bus_bit, lock_bit; + u8 has_gate, gate_bit; + + u8 mux_shift, mux_width; + u8 n_shift, n_width, n_min; + u8 d1_shift, d1_width; + u8 k_shift, k_width; + u8 m_shift, m_width; + u8 p_shift, p_width; + + u8 upd_bit; + + u8 features; + + const struct clk_div_table *div_table; + u32 div_flags; + + const struct ccu_extra *extra; +}; + +struct ccu_reset_map { + u16 reg; + u16 bit; +}; + +struct ccu_reset { + void __iomem *base; + const struct ccu_reset_map *reset_map; + struct reset_controller_dev rcdev; +}; + +extern const struct clk_ops ccu_fixed_factor_ops; +extern const struct clk_ops ccu_periph_ops; +extern const struct clk_ops ccu_pll_ops; +extern const struct clk_ops ccu_phase_ops; +extern const struct reset_control_ops ccu_reset_ops; + +static inline struct ccu *hw2ccu(struct clk_hw *hw) +{ + return container_of(hw, struct ccu, hw); +} + +int ccu_probe(struct device_node *node, + struct clk_hw_onecell_data *data, + struct ccu_reset *resets); + +/* functions exported for specific features */ +void ccu_set_clock(struct ccu *ccu, int reg, u32 mask, u32 val); +unsigned long ccu_fixed_factor_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate); +long ccu_fixed_factor_round_rate(struct clk_hw *hw, + unsigned long rate, + unsigned long *parent_rate); +int ccu_fixed_factor_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate); + +#endif /* _CCU_H_ */
Most of the clocks in the Allwinner's SoCs are configured in the CCU (Clock Configuration Unit). The PLL clocks are driven from the main clock. Their rates are controlled by a set of multiply and divide factors, named from the Allwinner's documentation: - multipliers: 'n' and 'k' - dividers: 'd1', 'd2', 'm' and 'p' The peripheral clocks may receive their inputs from one or more parents, thanks to a mux. Their rates are controlled by a set of divide factors only, named 'm' and 'p'. This driver also handles: - fixed clocks, - the phase delays for the MMCs, - the clock gates, - the bus gates, - and the resets. Signed-off-by: Jean-Francois Moine <moinejf@free.fr> --- drivers/clk/sunxi/Makefile | 2 + drivers/clk/sunxi/ccu.c | 980 +++++++++++++++++++++++++++++++++++++++++++++ drivers/clk/sunxi/ccu.h | 153 +++++++ 3 files changed, 1135 insertions(+) create mode 100644 drivers/clk/sunxi/ccu.c create mode 100644 drivers/clk/sunxi/ccu.h