| Message ID | 1513111858-6251-3-git-send-email-timur@codeaurora.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 2017-12-12 at 14:50 -0600, Timur Tabi wrote: > pinctrl-msm only accepts an array of GPIOs from 0 to n-1, and it > expects > each group to support have only one pin (npins == 1). > > We can support "sparse" GPIO maps if we allow for some groups to have > zero > pins (npins == 0). These pins are "hidden" from the rest of the > driver > and gpiolib. > > Access to unavailable GPIOs is blocked via a request callback. If the > requested GPIO is unavailable, -EACCES is returned, which prevents > further access to that GPIO. We recently have some interesting BIOS/Windows driver design which makes a need of something similar. Mika did patched pinctrl-intel for that. I dunno that approach can be used here, or your proposal be utilized in pinctrl-intel. Mika, any comments? See some nitpicks below. > > seq_printf(s, " %-8s: %-3s %d", g->name, is_out ? "out" : > "in", func); > seq_printf(s, " %dmA", msm_regval_to_drive(drive)); > - seq_printf(s, " %s", pulls[pull]); > + seq_printf(s, " %s\n", pulls[pull]); I would rather do seq_putc(s, '\n'); which makes code slightly more flexible for maintenance and reading. > } > > static void msm_gpio_dbg_show(struct seq_file *s, struct gpio_chip > *chip) > @@ -524,23 +529,36 @@ static void msm_gpio_dbg_show(struct seq_file > *s, struct gpio_chip *chip) > unsigned gpio = chip->base; > unsigned i; > > - for (i = 0; i < chip->ngpio; i++, gpio++) { > + for (i = 0; i < chip->ngpio; i++, gpio++) > msm_gpio_dbg_show_one(s, NULL, chip, i, gpio); > - seq_puts(s, "\n"); > - } This kind of change looks like a candidate to a separate patch, though I mentioned it's just a nit.
diff --git a/drivers/pinctrl/qcom/pinctrl-msm.c b/drivers/pinctrl/qcom/pinctrl-msm.c index 7a960590ecaa..d45b4c2b5af1 100644 --- a/drivers/pinctrl/qcom/pinctrl-msm.c +++ b/drivers/pinctrl/qcom/pinctrl-msm.c @@ -507,6 +507,11 @@ static void msm_gpio_dbg_show_one(struct seq_file *s, }; g = &pctrl->soc->groups[offset]; + + /* If the GPIO group has no pins, then don't show it. */ + if (!g->npins) + return; + ctl_reg = readl(pctrl->regs + g->ctl_reg); is_out = !!(ctl_reg & BIT(g->oe_bit)); @@ -516,7 +521,7 @@ static void msm_gpio_dbg_show_one(struct seq_file *s, seq_printf(s, " %-8s: %-3s %d", g->name, is_out ? "out" : "in", func); seq_printf(s, " %dmA", msm_regval_to_drive(drive)); - seq_printf(s, " %s", pulls[pull]); + seq_printf(s, " %s\n", pulls[pull]); } static void msm_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip) @@ -524,23 +529,36 @@ static void msm_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip) unsigned gpio = chip->base; unsigned i; - for (i = 0; i < chip->ngpio; i++, gpio++) { + for (i = 0; i < chip->ngpio; i++, gpio++) msm_gpio_dbg_show_one(s, NULL, chip, i, gpio); - seq_puts(s, "\n"); - } } #else #define msm_gpio_dbg_show NULL #endif +/* + * If the requested GPIO has no pins, then treat it as unavailable. + * Otherwise, call the standard request function. + */ +static int msm_gpio_request(struct gpio_chip *chip, unsigned int offset) +{ + struct msm_pinctrl *pctrl = gpiochip_get_data(chip); + const struct msm_pingroup *g = &pctrl->soc->groups[offset]; + + if (!g->npins) + return -EACCES; + + return gpiochip_generic_request(chip, offset); +} + static const struct gpio_chip msm_gpio_template = { .direction_input = msm_gpio_direction_input, .direction_output = msm_gpio_direction_output, .get_direction = msm_gpio_get_direction, .get = msm_gpio_get, .set = msm_gpio_set, - .request = gpiochip_generic_request, + .request = msm_gpio_request, .free = gpiochip_generic_free, .dbg_show = msm_gpio_dbg_show, };
pinctrl-msm only accepts an array of GPIOs from 0 to n-1, and it expects each group to support have only one pin (npins == 1). We can support "sparse" GPIO maps if we allow for some groups to have zero pins (npins == 0). These pins are "hidden" from the rest of the driver and gpiolib. Access to unavailable GPIOs is blocked via a request callback. If the requested GPIO is unavailable, -EACCES is returned, which prevents further access to that GPIO. Signed-off-by: Timur Tabi <timur@codeaurora.org> --- drivers/pinctrl/qcom/pinctrl-msm.c | 28 +++++++++++++++++++++++----- 1 file changed, 23 insertions(+), 5 deletions(-)