| Message ID | 20180321165848.89751-3-swboyd@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, 2018-03-21 at 09:58 -0700, Stephen Boyd wrote: > From: Stephen Boyd <sboyd@codeaurora.org> > > 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> Hmm... > + gpiochip->valid_mask = kcalloc(BITS_TO_LONGS(gpiochip- > >ngpio), > + sizeof(long), GFP_KERNEL); Just noticed that kcalloc is superfluous here. kmalloc_array() would be enough. > + if (!gpiochip->valid_mask) > + return -ENOMEM; > + > + /* Assume by default all GPIOs are valid */ > + bitmap_fill(gpiochip->valid_mask, gpiochip->ngpio);
On Wed, 2018-03-21 at 19:59 +0200, Andy Shevchenko wrote:
> On Wed, 2018-03-21 at 09:58 -0700, Stephen Boyd wrote:
After addressing comments,
Reviwed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Quoting Andy Shevchenko (2018-03-21 10:59:10) > On Wed, 2018-03-21 at 09:58 -0700, Stephen Boyd wrote: > > From: Stephen Boyd <sboyd@codeaurora.org> > > > > 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> > > Hmm... Don't look closely! :P > > > + gpiochip->valid_mask = kcalloc(BITS_TO_LONGS(gpiochip- > > >ngpio), > > + sizeof(long), GFP_KERNEL); > > Just noticed that kcalloc is superfluous here. > kmalloc_array() would be enough. > Ok. I was copying the irqchip style. Should I fold them together into a helper function and also update to kmalloc_array?
On Wed, 2018-03-21 at 12:59 -0700, Stephen Boyd wrote: > Quoting Andy Shevchenko (2018-03-21 10:59:10) > > On Wed, 2018-03-21 at 09:58 -0700, Stephen Boyd wrote: > > > > > > > > + gpiochip->valid_mask = kcalloc(BITS_TO_LONGS(gpiochip- > > > > ngpio), > > > > > > + sizeof(long), GFP_KERNEL); > > > > Just noticed that kcalloc is superfluous here. > > kmalloc_array() would be enough. > > > > Ok. I was copying the irqchip style. Should I fold them together into > a > helper function and also update to kmalloc_array? Not sure about first part, but definitely makes sense the second one (as a separate patch perhaps).
On Wed, Mar 21, 2018 at 8:59 PM, Stephen Boyd <swboyd@chromium.org> wrote: > Quoting Andy Shevchenko (2018-03-21 10:59:10) >> On Wed, 2018-03-21 at 09:58 -0700, Stephen Boyd wrote: >> > From: Stephen Boyd <sboyd@codeaurora.org> >> > >> > 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> >> >> Hmm... > > Don't look closely! :P Same physical person acting on behalf of two different legal entities right? Seems OK to me. Yours, Linus Walleij
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; diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index d66de67ef307..5861984774ac 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -337,6 +337,47 @@ static int gpiochip_set_desc_names(struct gpio_chip *gc) return 0; } +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 = kcalloc(BITS_TO_LONGS(gpiochip->ngpio), + sizeof(long), GFP_KERNEL); + if (!gpiochip->valid_mask) + return -ENOMEM; + + /* Assume by default all GPIOs are valid */ + bitmap_fill(gpiochip->valid_mask, gpiochip->ngpio); + + 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 */ @@ -1261,6 +1302,10 @@ 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; @@ -1290,6 +1335,8 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data, 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); @@ -1346,6 +1393,7 @@ 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 @@ -1526,6 +1574,8 @@ 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; diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index 1ba9a331ec51..5382b5183b7e 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -288,6 +288,21 @@ struct gpio_chip { struct gpio_irq_chip irq; #endif + /** + * @need_valid_mask: + * + * If set core allocates @valid_mask with all bits set to one. + */ + bool need_valid_mask; + + /** + * @valid_mask: + * + * If not %NULL holds bitmask of GPIOs which are valid to be used + * from the chip. + */ + unsigned long *valid_mask; + #if defined(CONFIG_OF_GPIO) /* * If CONFIG_OF is enabled, then all GPIO controllers described in the @@ -384,6 +399,7 @@ bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset); /* Sleep persistence inquiry for drivers */ bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset); +bool gpiochip_line_is_valid(const struct gpio_chip *chip, unsigned int offset); /* get driver data */ void *gpiochip_get_data(struct gpio_chip *chip);