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.c | |
parent | ace56935ff48879239d79129c7882ea2ff1b4804 (diff) | |
download | op-kernel-dev-726cb3ba49692bdae6caff457755e7cdb432efa4.zip op-kernel-dev-726cb3ba49692bdae6caff457755e7cdb432efa4.tar.gz |
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.c')
-rw-r--r-- | drivers/gpio/gpiolib.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index db3788d..fecbb55 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -351,6 +351,43 @@ static unsigned long *gpiochip_allocate_mask(struct gpio_chip *chip) return p; } +static int gpiochip_init_valid_mask(struct gpio_chip *gpiochip) +{ +#ifdef CONFIG_OF_GPIO + int size; + struct device_node *np = gpiochip->of_node; + + size = of_property_count_u32_elems(np, "gpio-reserved-ranges"); + if (size > 0 && size % 2 == 0) + gpiochip->need_valid_mask = true; +#endif + + if (!gpiochip->need_valid_mask) + return 0; + + gpiochip->valid_mask = gpiochip_allocate_mask(gpiochip); + if (!gpiochip->valid_mask) + return -ENOMEM; + + return 0; +} + +static void gpiochip_free_valid_mask(struct gpio_chip *gpiochip) +{ + kfree(gpiochip->valid_mask); + gpiochip->valid_mask = NULL; +} + +bool gpiochip_line_is_valid(const struct gpio_chip *gpiochip, + unsigned int offset) +{ + /* No mask means all valid */ + if (likely(!gpiochip->valid_mask)) + return true; + return test_bit(offset, gpiochip->valid_mask); +} +EXPORT_SYMBOL_GPL(gpiochip_line_is_valid); + /* * GPIO line handle management */ @@ -1275,6 +1312,10 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data, if (status) goto err_remove_from_list; + status = gpiochip_init_valid_mask(chip); + if (status) + goto err_remove_irqchip_mask; + status = gpiochip_add_irqchip(chip, lock_key, request_key); if (status) goto err_remove_chip; @@ -1304,6 +1345,8 @@ err_remove_chip: acpi_gpiochip_remove(chip); gpiochip_free_hogs(chip); of_gpiochip_remove(chip); + gpiochip_free_valid_mask(chip); +err_remove_irqchip_mask: gpiochip_irqchip_free_valid_mask(chip); err_remove_from_list: spin_lock_irqsave(&gpio_lock, flags); @@ -1360,6 +1403,7 @@ void gpiochip_remove(struct gpio_chip *chip) acpi_gpiochip_remove(chip); gpiochip_remove_pin_ranges(chip); of_gpiochip_remove(chip); + gpiochip_free_valid_mask(chip); /* * We accept no more calls into the driver from this point, so * NULL the driver data pointer @@ -1536,6 +1580,8 @@ static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip) bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip, unsigned int offset) { + if (!gpiochip_line_is_valid(gpiochip, offset)) + return false; /* No mask means all valid */ if (likely(!gpiochip->irq.valid_mask)) return true; |