| Message ID | Pine.LNX.4.64.1305211601180.2863@axis700.grange (mailing list archive) |
|---|---|
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On Tue, May 21, 2013 at 04:07:46PM +0200, Guennadi Liakhovetski wrote: > This patch adds support for the Z-clock on r8a7790 SoCs, which is driving > the Cortex A15 core, and a "cpufreq-cpu0" platform device. Adding an > "operating-points" property to the CPU0 DT node and a regulator, this > patch allows platforms to use the generic cpufreq-cpu0 driver to use > SoC's DVFS capabilities. > > Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com> > --- > > v2: > 1. a typo in the r8a7790 datasheet confused me to implement kick-bit > handling wrongly, this is fixed in this version > 2. patch 3 merged with this one > > Same comments, as to v1 of this series, apply. Magnus, could you please review this series? > > arch/arm/mach-shmobile/Kconfig | 2 + > arch/arm/mach-shmobile/clock-r8a7790.c | 129 ++++++++++++++++++++++++++++++++ > arch/arm/mach-shmobile/setup-r8a7790.c | 1 + > 3 files changed, 132 insertions(+), 0 deletions(-) > > diff --git a/arch/arm/mach-shmobile/Kconfig b/arch/arm/mach-shmobile/Kconfig > index 0319cf9..97bc6cf 100644 > --- a/arch/arm/mach-shmobile/Kconfig > +++ b/arch/arm/mach-shmobile/Kconfig > @@ -60,6 +60,8 @@ config ARCH_R8A7790 > select ARM_ARCH_TIMER > select SH_CLK_CPG > select RENESAS_IRQC > + select ARCH_HAS_CPUFREQ > + select ARCH_HAS_OPP > > config ARCH_EMEV2 > bool "Emma Mobile EV2" > diff --git a/arch/arm/mach-shmobile/clock-r8a7790.c b/arch/arm/mach-shmobile/clock-r8a7790.c > index 53a13b4..0f2aa68 100644 > --- a/arch/arm/mach-shmobile/clock-r8a7790.c > +++ b/arch/arm/mach-shmobile/clock-r8a7790.c > @@ -47,6 +47,9 @@ > #define CPG_BASE 0xe6150000 > #define CPG_LEN 0x1000 > > +#define FRQCRB 0xe6150004 > +#define FRQCRC 0xe61500e0 > + > #define SMSTPCR2 0xe6150138 > #define SMSTPCR3 0xe615013c > #define SMSTPCR7 0xe615014c > @@ -83,11 +86,132 @@ static struct clk main_clk = { > * clock ratio of these clock will be updated > * on r8a7790_clock_init() > */ > +SH_FIXED_RATIO_CLK_SET(pll0_clk, main_clk, 1, 1); > SH_FIXED_RATIO_CLK_SET(pll1_clk, main_clk, 1, 1); > SH_FIXED_RATIO_CLK_SET(pll3_clk, main_clk, 1, 1); > SH_FIXED_RATIO_CLK_SET(lb_clk, pll1_clk, 1, 1); > SH_FIXED_RATIO_CLK_SET(qspi_clk, pll1_clk, 1, 1); > > +/* If more clocks need to access FRQCRB, we'll have to lock eventually */ > +static int frqcr_kick_check(struct clk *clk) > +{ > + return ioread32(clk->mapped_reg) & BIT(31) ? -EBUSY : 0; > +} > + > +static int frqcr_kick_do(struct clk *clk) > +{ > + int i; > + > + /* set KICK bit in FRQCRB to update hardware setting, check success */ > + iowrite32(ioread32(clk->mapped_reg) | BIT(31), clk->mapped_reg); > + for (i = 1000; i; i--) > + if (ioread32(clk->mapped_reg) & BIT(31)) > + cpu_relax(); > + else > + return 0; > + > + return -ETIMEDOUT; > +} > + > +static int zclk_set_rate(struct clk *clk, unsigned long rate) > +{ > + void __iomem *frqcrc; > + int ret; > + unsigned long step, p_rate; > + u32 val; > + > + if (!clk->parent || !__clk_get(clk->parent)) > + return -ENODEV; > + > + ret = frqcr_kick_check(clk); > + if (ret < 0) > + goto done; > + > + frqcrc = clk->mapped_reg + (FRQCRC - (u32)clk->enable_reg); > + > + p_rate = clk_get_rate(clk->parent); > + if (rate == p_rate) { > + val = 0; > + } else { > + step = DIV_ROUND_CLOSEST(p_rate, 32); > + val = 32 - rate / step; > + } > + > + iowrite32((ioread32(frqcrc) & ~(clk->div_mask << clk->enable_bit)) | > + (val << clk->enable_bit), frqcrc); > + > + ret = frqcr_kick_do(clk); > + > +done: > + __clk_put(clk->parent); > + return ret; > +} > + > +static long zclk_round_rate(struct clk *clk, unsigned long rate) > +{ > + /* > + * theoretical rate = parent rate * multiplier / 32, > + * where 1 <= multiplier <= 32. Therefore we should do > + * multiplier = rate * 32 / parent rate > + * rounded rate = parent rate * multiplier / 32. > + * However, multiplication before division won't fit in 32 bits, so > + * we sacrifice some precision by first dividing and then multiplying. > + * To find the nearest divisor we calculate both and pick up the best > + * one. This avoids 64-bit arithmetics. > + */ > + unsigned long step, mul_min, mul_max, rate_min, rate_max; > + > + rate_max = clk_get_rate(clk->parent); > + > + /* output freq <= parent */ > + if (rate >= rate_max) > + return rate_max; > + > + step = DIV_ROUND_CLOSEST(rate_max, 32); > + /* output freq >= parent / 32 */ > + if (step >= rate) > + return step; > + > + mul_min = rate / step; > + mul_max = DIV_ROUND_UP(rate, step); > + rate_min = step * mul_min; > + if (mul_max == mul_min) > + return rate_min; > + > + rate_max = step * mul_max; > + > + if (rate_max - rate < rate - rate_min) > + return rate_max; > + > + return rate_min; > +} > + > +static unsigned long zclk_recalc(struct clk *clk) > +{ > + void __iomem *frqcrc = FRQCRC - (u32)clk->enable_reg + clk->mapped_reg; > + unsigned int max = clk->div_mask + 1; > + unsigned long val = ((ioread32(frqcrc) >> clk->enable_bit) & > + clk->div_mask); > + > + return DIV_ROUND_CLOSEST(clk_get_rate(clk->parent), max) * > + (max - val); > +} > + > +static struct sh_clk_ops zclk_ops = { > + .recalc = zclk_recalc, > + .set_rate = zclk_set_rate, > + .round_rate = zclk_round_rate, > +}; > + > +static struct clk z_clk = { > + .parent = &pll0_clk, > + .div_mask = 0x1f, > + .enable_bit = 8, > + /* We'll need to access FRQCRB and FRQCRC */ > + .enable_reg = (void __iomem *)FRQCRB, > + .ops = &zclk_ops, > +}; > + > /* fixed ratio clock */ > SH_FIXED_RATIO_CLK_SET(extal_div2_clk, extal_clk, 1, 2); > SH_FIXED_RATIO_CLK_SET(cp_clk, extal_clk, 1, 2); > @@ -115,11 +239,13 @@ static struct clk *main_clks[] = { > &extal_clk, > &extal_div2_clk, > &main_clk, > + &pll0_clk, > &pll1_clk, > &pll1_div2_clk, > &pll3_clk, > &lb_clk, > &qspi_clk, > + &z_clk, > &zg_clk, > &zx_clk, > &zs_clk, > @@ -213,6 +339,7 @@ static struct clk_lookup lookups[] = { > CLKDEV_CON_ID("pll1", &pll1_clk), > CLKDEV_CON_ID("pll1_div2", &pll1_div2_clk), > CLKDEV_CON_ID("pll3", &pll3_clk), > + CLKDEV_DEV_ID("cpufreq-cpu0", &z_clk), > CLKDEV_CON_ID("zg", &zg_clk), > CLKDEV_CON_ID("zx", &zx_clk), > CLKDEV_CON_ID("zs", &zs_clk), > @@ -263,9 +390,11 @@ static struct clk_lookup lookups[] = { > CLKDEV_DEV_ID("sh_mmcif.1", &mstp_clks[MSTP305]), > }; > > +/* "/ 2" is a "fixed divider" - see the "PLL Multiplication Ratio" table */ > #define R8A7790_CLOCK_ROOT(e, m, p0, p1, p30, p31) \ > extal_clk.rate = e * 1000 * 1000; \ > main_clk.parent = m; \ > + SH_CLK_SET_RATIO(&pll0_clk_ratio, p0 / 2, 1); \ > SH_CLK_SET_RATIO(&pll1_clk_ratio, p1 / 2, 1); \ > if (mode & MD(19)) \ > SH_CLK_SET_RATIO(&pll3_clk_ratio, p31, 1); \ > diff --git a/arch/arm/mach-shmobile/setup-r8a7790.c b/arch/arm/mach-shmobile/setup-r8a7790.c > index eeef5f6..49c3166 100644 > --- a/arch/arm/mach-shmobile/setup-r8a7790.c > +++ b/arch/arm/mach-shmobile/setup-r8a7790.c > @@ -166,6 +166,7 @@ void __init r8a7790_timer_init(void) > #ifdef CONFIG_USE_OF > void __init r8a7790_add_standard_devices_dt(void) > { > + platform_device_register_simple("cpufreq-cpu0", -1, NULL, 0); > of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL); > } > > -- > 1.7.2.5 >
On Sat, May 25, 2013 at 10:34:45AM +0900, Simon Horman wrote: > On Tue, May 21, 2013 at 04:07:46PM +0200, Guennadi Liakhovetski wrote: > > This patch adds support for the Z-clock on r8a7790 SoCs, which is driving > > the Cortex A15 core, and a "cpufreq-cpu0" platform device. Adding an > > "operating-points" property to the CPU0 DT node and a regulator, this > > patch allows platforms to use the generic cpufreq-cpu0 driver to use > > SoC's DVFS capabilities. > > > > Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com> > > --- > > > > v2: > > 1. a typo in the r8a7790 datasheet confused me to implement kick-bit > > handling wrongly, this is fixed in this version > > 2. patch 3 merged with this one > > > > Same comments, as to v1 of this series, apply. > > Magnus, > > could you please review this series? I have marked this patch as deferred in the patch tracker as it has been rotting there for several months now. I will need the following before taking it into the tree: 1. Repost, rebased if needed. 2. An ack from Magnus or indication from him that someone else should review it. > > > > > arch/arm/mach-shmobile/Kconfig | 2 + > > arch/arm/mach-shmobile/clock-r8a7790.c | 129 ++++++++++++++++++++++++++++++++ > > arch/arm/mach-shmobile/setup-r8a7790.c | 1 + > > 3 files changed, 132 insertions(+), 0 deletions(-) > > > > diff --git a/arch/arm/mach-shmobile/Kconfig b/arch/arm/mach-shmobile/Kconfig > > index 0319cf9..97bc6cf 100644 > > --- a/arch/arm/mach-shmobile/Kconfig > > +++ b/arch/arm/mach-shmobile/Kconfig > > @@ -60,6 +60,8 @@ config ARCH_R8A7790 > > select ARM_ARCH_TIMER > > select SH_CLK_CPG > > select RENESAS_IRQC > > + select ARCH_HAS_CPUFREQ > > + select ARCH_HAS_OPP > > > > config ARCH_EMEV2 > > bool "Emma Mobile EV2" > > diff --git a/arch/arm/mach-shmobile/clock-r8a7790.c b/arch/arm/mach-shmobile/clock-r8a7790.c > > index 53a13b4..0f2aa68 100644 > > --- a/arch/arm/mach-shmobile/clock-r8a7790.c > > +++ b/arch/arm/mach-shmobile/clock-r8a7790.c > > @@ -47,6 +47,9 @@ > > #define CPG_BASE 0xe6150000 > > #define CPG_LEN 0x1000 > > > > +#define FRQCRB 0xe6150004 > > +#define FRQCRC 0xe61500e0 > > + > > #define SMSTPCR2 0xe6150138 > > #define SMSTPCR3 0xe615013c > > #define SMSTPCR7 0xe615014c > > @@ -83,11 +86,132 @@ static struct clk main_clk = { > > * clock ratio of these clock will be updated > > * on r8a7790_clock_init() > > */ > > +SH_FIXED_RATIO_CLK_SET(pll0_clk, main_clk, 1, 1); > > SH_FIXED_RATIO_CLK_SET(pll1_clk, main_clk, 1, 1); > > SH_FIXED_RATIO_CLK_SET(pll3_clk, main_clk, 1, 1); > > SH_FIXED_RATIO_CLK_SET(lb_clk, pll1_clk, 1, 1); > > SH_FIXED_RATIO_CLK_SET(qspi_clk, pll1_clk, 1, 1); > > > > +/* If more clocks need to access FRQCRB, we'll have to lock eventually */ > > +static int frqcr_kick_check(struct clk *clk) > > +{ > > + return ioread32(clk->mapped_reg) & BIT(31) ? -EBUSY : 0; > > +} > > + > > +static int frqcr_kick_do(struct clk *clk) > > +{ > > + int i; > > + > > + /* set KICK bit in FRQCRB to update hardware setting, check success */ > > + iowrite32(ioread32(clk->mapped_reg) | BIT(31), clk->mapped_reg); > > + for (i = 1000; i; i--) > > + if (ioread32(clk->mapped_reg) & BIT(31)) > > + cpu_relax(); > > + else > > + return 0; > > + > > + return -ETIMEDOUT; > > +} > > + > > +static int zclk_set_rate(struct clk *clk, unsigned long rate) > > +{ > > + void __iomem *frqcrc; > > + int ret; > > + unsigned long step, p_rate; > > + u32 val; > > + > > + if (!clk->parent || !__clk_get(clk->parent)) > > + return -ENODEV; > > + > > + ret = frqcr_kick_check(clk); > > + if (ret < 0) > > + goto done; > > + > > + frqcrc = clk->mapped_reg + (FRQCRC - (u32)clk->enable_reg); > > + > > + p_rate = clk_get_rate(clk->parent); > > + if (rate == p_rate) { > > + val = 0; > > + } else { > > + step = DIV_ROUND_CLOSEST(p_rate, 32); > > + val = 32 - rate / step; > > + } > > + > > + iowrite32((ioread32(frqcrc) & ~(clk->div_mask << clk->enable_bit)) | > > + (val << clk->enable_bit), frqcrc); > > + > > + ret = frqcr_kick_do(clk); > > + > > +done: > > + __clk_put(clk->parent); > > + return ret; > > +} > > + > > +static long zclk_round_rate(struct clk *clk, unsigned long rate) > > +{ > > + /* > > + * theoretical rate = parent rate * multiplier / 32, > > + * where 1 <= multiplier <= 32. Therefore we should do > > + * multiplier = rate * 32 / parent rate > > + * rounded rate = parent rate * multiplier / 32. > > + * However, multiplication before division won't fit in 32 bits, so > > + * we sacrifice some precision by first dividing and then multiplying. > > + * To find the nearest divisor we calculate both and pick up the best > > + * one. This avoids 64-bit arithmetics. > > + */ > > + unsigned long step, mul_min, mul_max, rate_min, rate_max; > > + > > + rate_max = clk_get_rate(clk->parent); > > + > > + /* output freq <= parent */ > > + if (rate >= rate_max) > > + return rate_max; > > + > > + step = DIV_ROUND_CLOSEST(rate_max, 32); > > + /* output freq >= parent / 32 */ > > + if (step >= rate) > > + return step; > > + > > + mul_min = rate / step; > > + mul_max = DIV_ROUND_UP(rate, step); > > + rate_min = step * mul_min; > > + if (mul_max == mul_min) > > + return rate_min; > > + > > + rate_max = step * mul_max; > > + > > + if (rate_max - rate < rate - rate_min) > > + return rate_max; > > + > > + return rate_min; > > +} > > + > > +static unsigned long zclk_recalc(struct clk *clk) > > +{ > > + void __iomem *frqcrc = FRQCRC - (u32)clk->enable_reg + clk->mapped_reg; > > + unsigned int max = clk->div_mask + 1; > > + unsigned long val = ((ioread32(frqcrc) >> clk->enable_bit) & > > + clk->div_mask); > > + > > + return DIV_ROUND_CLOSEST(clk_get_rate(clk->parent), max) * > > + (max - val); > > +} > > + > > +static struct sh_clk_ops zclk_ops = { > > + .recalc = zclk_recalc, > > + .set_rate = zclk_set_rate, > > + .round_rate = zclk_round_rate, > > +}; > > + > > +static struct clk z_clk = { > > + .parent = &pll0_clk, > > + .div_mask = 0x1f, > > + .enable_bit = 8, > > + /* We'll need to access FRQCRB and FRQCRC */ > > + .enable_reg = (void __iomem *)FRQCRB, > > + .ops = &zclk_ops, > > +}; > > + > > /* fixed ratio clock */ > > SH_FIXED_RATIO_CLK_SET(extal_div2_clk, extal_clk, 1, 2); > > SH_FIXED_RATIO_CLK_SET(cp_clk, extal_clk, 1, 2); > > @@ -115,11 +239,13 @@ static struct clk *main_clks[] = { > > &extal_clk, > > &extal_div2_clk, > > &main_clk, > > + &pll0_clk, > > &pll1_clk, > > &pll1_div2_clk, > > &pll3_clk, > > &lb_clk, > > &qspi_clk, > > + &z_clk, > > &zg_clk, > > &zx_clk, > > &zs_clk, > > @@ -213,6 +339,7 @@ static struct clk_lookup lookups[] = { > > CLKDEV_CON_ID("pll1", &pll1_clk), > > CLKDEV_CON_ID("pll1_div2", &pll1_div2_clk), > > CLKDEV_CON_ID("pll3", &pll3_clk), > > + CLKDEV_DEV_ID("cpufreq-cpu0", &z_clk), > > CLKDEV_CON_ID("zg", &zg_clk), > > CLKDEV_CON_ID("zx", &zx_clk), > > CLKDEV_CON_ID("zs", &zs_clk), > > @@ -263,9 +390,11 @@ static struct clk_lookup lookups[] = { > > CLKDEV_DEV_ID("sh_mmcif.1", &mstp_clks[MSTP305]), > > }; > > > > +/* "/ 2" is a "fixed divider" - see the "PLL Multiplication Ratio" table */ > > #define R8A7790_CLOCK_ROOT(e, m, p0, p1, p30, p31) \ > > extal_clk.rate = e * 1000 * 1000; \ > > main_clk.parent = m; \ > > + SH_CLK_SET_RATIO(&pll0_clk_ratio, p0 / 2, 1); \ > > SH_CLK_SET_RATIO(&pll1_clk_ratio, p1 / 2, 1); \ > > if (mode & MD(19)) \ > > SH_CLK_SET_RATIO(&pll3_clk_ratio, p31, 1); \ > > diff --git a/arch/arm/mach-shmobile/setup-r8a7790.c b/arch/arm/mach-shmobile/setup-r8a7790.c > > index eeef5f6..49c3166 100644 > > --- a/arch/arm/mach-shmobile/setup-r8a7790.c > > +++ b/arch/arm/mach-shmobile/setup-r8a7790.c > > @@ -166,6 +166,7 @@ void __init r8a7790_timer_init(void) > > #ifdef CONFIG_USE_OF > > void __init r8a7790_add_standard_devices_dt(void) > > { > > + platform_device_register_simple("cpufreq-cpu0", -1, NULL, 0); > > of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL); > > } > > > > -- > > 1.7.2.5 > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-sh" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >
Hi Simon Thanks for following on this. On Wed, 25 Sep 2013, Simon Horman wrote: > On Sat, May 25, 2013 at 10:34:45AM +0900, Simon Horman wrote: > > On Tue, May 21, 2013 at 04:07:46PM +0200, Guennadi Liakhovetski wrote: > > > This patch adds support for the Z-clock on r8a7790 SoCs, which is driving > > > the Cortex A15 core, and a "cpufreq-cpu0" platform device. Adding an > > > "operating-points" property to the CPU0 DT node and a regulator, this > > > patch allows platforms to use the generic cpufreq-cpu0 driver to use > > > SoC's DVFS capabilities. > > > > > > Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com> > > > --- > > > > > > v2: > > > 1. a typo in the r8a7790 datasheet confused me to implement kick-bit > > > handling wrongly, this is fixed in this version > > > 2. patch 3 merged with this one > > > > > > Same comments, as to v1 of this series, apply. > > > > Magnus, > > > > could you please review this series? > > I have marked this patch as deferred in the patch tracker > as it has been rotting there for several months now. > > I will need the following before taking it into the tree: > 1. Repost, rebased if needed. > 2. An ack from Magnus or indication from him that someone else should > review it. This patch is superseded by my recent patches [PATCH 3/4] ARM: shmobile: r8a7790: add CPUFreq clock support [PATCH/RFC 4/4] ARM: shmobile: lager: add CPUFreq support Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/
On Thu, Sep 26, 2013 at 10:56:02AM +0200, Guennadi Liakhovetski wrote: > Hi Simon > > Thanks for following on this. > > On Wed, 25 Sep 2013, Simon Horman wrote: > > > On Sat, May 25, 2013 at 10:34:45AM +0900, Simon Horman wrote: > > > On Tue, May 21, 2013 at 04:07:46PM +0200, Guennadi Liakhovetski wrote: > > > > This patch adds support for the Z-clock on r8a7790 SoCs, which is driving > > > > the Cortex A15 core, and a "cpufreq-cpu0" platform device. Adding an > > > > "operating-points" property to the CPU0 DT node and a regulator, this > > > > patch allows platforms to use the generic cpufreq-cpu0 driver to use > > > > SoC's DVFS capabilities. > > > > > > > > Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com> > > > > --- > > > > > > > > v2: > > > > 1. a typo in the r8a7790 datasheet confused me to implement kick-bit > > > > handling wrongly, this is fixed in this version > > > > 2. patch 3 merged with this one > > > > > > > > Same comments, as to v1 of this series, apply. > > > > > > Magnus, > > > > > > could you please review this series? > > > > I have marked this patch as deferred in the patch tracker > > as it has been rotting there for several months now. > > > > I will need the following before taking it into the tree: > > 1. Repost, rebased if needed. > > 2. An ack from Magnus or indication from him that someone else should > > review it. > > This patch is superseded by my recent patches > > [PATCH 3/4] ARM: shmobile: r8a7790: add CPUFreq clock support > [PATCH/RFC 4/4] ARM: shmobile: lager: add CPUFreq support Thanks, noted.
diff --git a/arch/arm/mach-shmobile/Kconfig b/arch/arm/mach-shmobile/Kconfig index 0319cf9..97bc6cf 100644 --- a/arch/arm/mach-shmobile/Kconfig +++ b/arch/arm/mach-shmobile/Kconfig @@ -60,6 +60,8 @@ config ARCH_R8A7790 select ARM_ARCH_TIMER select SH_CLK_CPG select RENESAS_IRQC + select ARCH_HAS_CPUFREQ + select ARCH_HAS_OPP config ARCH_EMEV2 bool "Emma Mobile EV2" diff --git a/arch/arm/mach-shmobile/clock-r8a7790.c b/arch/arm/mach-shmobile/clock-r8a7790.c index 53a13b4..0f2aa68 100644 --- a/arch/arm/mach-shmobile/clock-r8a7790.c +++ b/arch/arm/mach-shmobile/clock-r8a7790.c @@ -47,6 +47,9 @@ #define CPG_BASE 0xe6150000 #define CPG_LEN 0x1000 +#define FRQCRB 0xe6150004 +#define FRQCRC 0xe61500e0 + #define SMSTPCR2 0xe6150138 #define SMSTPCR3 0xe615013c #define SMSTPCR7 0xe615014c @@ -83,11 +86,132 @@ static struct clk main_clk = { * clock ratio of these clock will be updated * on r8a7790_clock_init() */ +SH_FIXED_RATIO_CLK_SET(pll0_clk, main_clk, 1, 1); SH_FIXED_RATIO_CLK_SET(pll1_clk, main_clk, 1, 1); SH_FIXED_RATIO_CLK_SET(pll3_clk, main_clk, 1, 1); SH_FIXED_RATIO_CLK_SET(lb_clk, pll1_clk, 1, 1); SH_FIXED_RATIO_CLK_SET(qspi_clk, pll1_clk, 1, 1); +/* If more clocks need to access FRQCRB, we'll have to lock eventually */ +static int frqcr_kick_check(struct clk *clk) +{ + return ioread32(clk->mapped_reg) & BIT(31) ? -EBUSY : 0; +} + +static int frqcr_kick_do(struct clk *clk) +{ + int i; + + /* set KICK bit in FRQCRB to update hardware setting, check success */ + iowrite32(ioread32(clk->mapped_reg) | BIT(31), clk->mapped_reg); + for (i = 1000; i; i--) + if (ioread32(clk->mapped_reg) & BIT(31)) + cpu_relax(); + else + return 0; + + return -ETIMEDOUT; +} + +static int zclk_set_rate(struct clk *clk, unsigned long rate) +{ + void __iomem *frqcrc; + int ret; + unsigned long step, p_rate; + u32 val; + + if (!clk->parent || !__clk_get(clk->parent)) + return -ENODEV; + + ret = frqcr_kick_check(clk); + if (ret < 0) + goto done; + + frqcrc = clk->mapped_reg + (FRQCRC - (u32)clk->enable_reg); + + p_rate = clk_get_rate(clk->parent); + if (rate == p_rate) { + val = 0; + } else { + step = DIV_ROUND_CLOSEST(p_rate, 32); + val = 32 - rate / step; + } + + iowrite32((ioread32(frqcrc) & ~(clk->div_mask << clk->enable_bit)) | + (val << clk->enable_bit), frqcrc); + + ret = frqcr_kick_do(clk); + +done: + __clk_put(clk->parent); + return ret; +} + +static long zclk_round_rate(struct clk *clk, unsigned long rate) +{ + /* + * theoretical rate = parent rate * multiplier / 32, + * where 1 <= multiplier <= 32. Therefore we should do + * multiplier = rate * 32 / parent rate + * rounded rate = parent rate * multiplier / 32. + * However, multiplication before division won't fit in 32 bits, so + * we sacrifice some precision by first dividing and then multiplying. + * To find the nearest divisor we calculate both and pick up the best + * one. This avoids 64-bit arithmetics. + */ + unsigned long step, mul_min, mul_max, rate_min, rate_max; + + rate_max = clk_get_rate(clk->parent); + + /* output freq <= parent */ + if (rate >= rate_max) + return rate_max; + + step = DIV_ROUND_CLOSEST(rate_max, 32); + /* output freq >= parent / 32 */ + if (step >= rate) + return step; + + mul_min = rate / step; + mul_max = DIV_ROUND_UP(rate, step); + rate_min = step * mul_min; + if (mul_max == mul_min) + return rate_min; + + rate_max = step * mul_max; + + if (rate_max - rate < rate - rate_min) + return rate_max; + + return rate_min; +} + +static unsigned long zclk_recalc(struct clk *clk) +{ + void __iomem *frqcrc = FRQCRC - (u32)clk->enable_reg + clk->mapped_reg; + unsigned int max = clk->div_mask + 1; + unsigned long val = ((ioread32(frqcrc) >> clk->enable_bit) & + clk->div_mask); + + return DIV_ROUND_CLOSEST(clk_get_rate(clk->parent), max) * + (max - val); +} + +static struct sh_clk_ops zclk_ops = { + .recalc = zclk_recalc, + .set_rate = zclk_set_rate, + .round_rate = zclk_round_rate, +}; + +static struct clk z_clk = { + .parent = &pll0_clk, + .div_mask = 0x1f, + .enable_bit = 8, + /* We'll need to access FRQCRB and FRQCRC */ + .enable_reg = (void __iomem *)FRQCRB, + .ops = &zclk_ops, +}; + /* fixed ratio clock */ SH_FIXED_RATIO_CLK_SET(extal_div2_clk, extal_clk, 1, 2); SH_FIXED_RATIO_CLK_SET(cp_clk, extal_clk, 1, 2); @@ -115,11 +239,13 @@ static struct clk *main_clks[] = { &extal_clk, &extal_div2_clk, &main_clk, + &pll0_clk, &pll1_clk, &pll1_div2_clk, &pll3_clk, &lb_clk, &qspi_clk, + &z_clk, &zg_clk, &zx_clk, &zs_clk, @@ -213,6 +339,7 @@ static struct clk_lookup lookups[] = { CLKDEV_CON_ID("pll1", &pll1_clk), CLKDEV_CON_ID("pll1_div2", &pll1_div2_clk), CLKDEV_CON_ID("pll3", &pll3_clk), + CLKDEV_DEV_ID("cpufreq-cpu0", &z_clk), CLKDEV_CON_ID("zg", &zg_clk), CLKDEV_CON_ID("zx", &zx_clk), CLKDEV_CON_ID("zs", &zs_clk), @@ -263,9 +390,11 @@ static struct clk_lookup lookups[] = { CLKDEV_DEV_ID("sh_mmcif.1", &mstp_clks[MSTP305]), }; +/* "/ 2" is a "fixed divider" - see the "PLL Multiplication Ratio" table */ #define R8A7790_CLOCK_ROOT(e, m, p0, p1, p30, p31) \ extal_clk.rate = e * 1000 * 1000; \ main_clk.parent = m; \ + SH_CLK_SET_RATIO(&pll0_clk_ratio, p0 / 2, 1); \ SH_CLK_SET_RATIO(&pll1_clk_ratio, p1 / 2, 1); \ if (mode & MD(19)) \ SH_CLK_SET_RATIO(&pll3_clk_ratio, p31, 1); \ diff --git a/arch/arm/mach-shmobile/setup-r8a7790.c b/arch/arm/mach-shmobile/setup-r8a7790.c index eeef5f6..49c3166 100644 --- a/arch/arm/mach-shmobile/setup-r8a7790.c +++ b/arch/arm/mach-shmobile/setup-r8a7790.c @@ -166,6 +166,7 @@ void __init r8a7790_timer_init(void) #ifdef CONFIG_USE_OF void __init r8a7790_add_standard_devices_dt(void) { + platform_device_register_simple("cpufreq-cpu0", -1, NULL, 0); of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL); }
This patch adds support for the Z-clock on r8a7790 SoCs, which is driving the Cortex A15 core, and a "cpufreq-cpu0" platform device. Adding an "operating-points" property to the CPU0 DT node and a regulator, this patch allows platforms to use the generic cpufreq-cpu0 driver to use SoC's DVFS capabilities. Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com> --- v2: 1. a typo in the r8a7790 datasheet confused me to implement kick-bit handling wrongly, this is fixed in this version 2. patch 3 merged with this one Same comments, as to v1 of this series, apply. arch/arm/mach-shmobile/Kconfig | 2 + arch/arm/mach-shmobile/clock-r8a7790.c | 129 ++++++++++++++++++++++++++++++++ arch/arm/mach-shmobile/setup-r8a7790.c | 1 + 3 files changed, 132 insertions(+), 0 deletions(-)