diff options
| author | Stephen Boyd <sboyd@codeaurora.org> | 2018-03-23 09:34:52 -0700 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2018-03-27 15:34:20 +0200 |
| commit | 726cb3ba49692bdae6caff457755e7cdb432efa4 (patch) | |
| tree | 66bf4de79b830df2556fa8854dcba1d414ebd9a4 /drivers/gpio/gpiolib-of.c | |
| parent | ace56935ff48879239d79129c7882ea2ff1b4804 (diff) | |
| download | linux-726cb3ba49692bdae6caff457755e7cdb432efa4.tar.bz2 | |
gpiolib: Support 'gpio-reserved-ranges' property
Some qcom platforms make some GPIOs or pins unavailable for use by
non-secure operating systems, and thus reading or writing the registers
for those pins will cause access control issues. Add support for a DT
property to describe the set of GPIOs that are available for use so that
higher level OSes are able to know what pins to avoid reading/writing.
Non-DT platforms can add support by directly updating the
chip->valid_mask.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Tested-by: Timur Tabi <timur@codeaurora.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio/gpiolib-of.c')
| -rw-r--r-- | drivers/gpio/gpiolib-of.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index 84e5a9df2344..ed81d9a6316f 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -511,6 +511,28 @@ void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc) } EXPORT_SYMBOL(of_mm_gpiochip_remove); +static void of_gpiochip_init_valid_mask(struct gpio_chip *chip) +{ + int len, i; + u32 start, count; + struct device_node *np = chip->of_node; + + len = of_property_count_u32_elems(np, "gpio-reserved-ranges"); + if (len < 0 || len % 2 != 0) + return; + + for (i = 0; i < len; i += 2) { + of_property_read_u32_index(np, "gpio-reserved-ranges", + i, &start); + of_property_read_u32_index(np, "gpio-reserved-ranges", + i + 1, &count); + if (start >= chip->ngpio || start + count >= chip->ngpio) + continue; + + bitmap_clear(chip->valid_mask, start, count); + } +}; + #ifdef CONFIG_PINCTRL static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { @@ -615,6 +637,8 @@ int of_gpiochip_add(struct gpio_chip *chip) if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS) return -EINVAL; + of_gpiochip_init_valid_mask(chip); + status = of_gpiochip_add_pin_range(chip); if (status) return status; |