Message ID | 20200525190845.60959-1-andriy.shevchenko@linux.intel.com |
---|---|
State | New |
Headers | show |
Series | [v2] gpio: pca953x: Override IRQ for one of the expanders on Galileo Gen 2 | expand |
On Mon, May 25, 2020 at 10:08:45PM +0300, Andy Shevchenko wrote: > ACPI table on Intel Galileo Gen 2 has wrong pin number for IRQ resource > of one of the I²C GPIO expanders. Since we know what that number is and > luckily have GPIO bases fixed for SoC's controllers, we may use a simple > DMI quirk to match the platform and retrieve GpioInt() pin on it for > the expander in question. > > Suggested-by: Mika Westerberg <mika.westerberg@linux.intel.com> > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > --- > v2: did everything in the driver (Mika) > drivers/gpio/gpio-pca953x.c | 65 +++++++++++++++++++++++++++++++++++++ > 1 file changed, 65 insertions(+) > > diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c > index 1fca8dd7824f..0d30f19782a2 100644 > --- a/drivers/gpio/gpio-pca953x.c > +++ b/drivers/gpio/gpio-pca953x.c > @@ -10,6 +10,7 @@ > > #include <linux/acpi.h> > #include <linux/bitmap.h> > +#include <linux/dmi.h> > #include <linux/gpio/driver.h> > #include <linux/gpio/consumer.h> > #include <linux/i2c.h> > @@ -107,6 +108,62 @@ static const struct i2c_device_id pca953x_id[] = { > }; > MODULE_DEVICE_TABLE(i2c, pca953x_id); > > +#ifdef CONFIG_GPIO_PCA953X_IRQ > +static const struct dmi_system_id pca953x_dmi_acpi_irq_info[] = { > + { > + /* > + * On Intel Galileo Gen 2 board the IRQ pin of one of > + * the I²C GPIO expanders, which has GpioInt() resource, > + * is provided as an absolute number instead of being > + * relative. Since first controller (gpio-sch.c) and > + * second (gpio-dwapb.c) are at the fixed bases, we may > + * safely refer to the number in the global space to get > + * an IRQ out of it. > + */ > + .matches = { > + DMI_EXACT_MATCH(DMI_BOARD_NAME, "GalileoGen2"), > + }, > + }, > + {} > +}; > + > +#ifdef CONFIG_ACPI > +static acpi_status pca953x_acpi_get_pin(struct acpi_resource *ares, void *data) > +{ > + struct acpi_resource_gpio *agpio; > + int *pin = data; > + > + if (!acpi_gpio_get_irq_resource(ares, &agpio)) > + return AE_OK; > + > + *pin = agpio->pin_table[0]; > + return AE_CTRL_TERMINATE; > +} > + > +static int pca953x_acpi_find_pin(acpi_handle handle) > +{ > + int p = -ENOENT; > + > + acpi_walk_resources(handle, METHOD_NAME__CRS, pca953x_acpi_get_pin, &p); > + return p; > +} > +#else > +static inline int pca953x_acpi_find_pin(acpi_handle handle) { return -ENXIO; } > +#endif > + > +static int pca953x_acpi_get_irq(struct device *dev) > +{ > + int pin; > + > + pin = pca953x_acpi_find_pin(ACPI_HANDLE(dev)); > + if (pin < 0) > + return pin; > + > + dev_info(dev, "Applying ACPI interrupt quirk (GPIO %d)\n", pin); > + return gpiod_to_irq(gpio_to_desc(pin)); You need to request the GPIO as well, I missed that from my example. Sorry about that. Otherwise looks good.
On Tue, May 26, 2020 at 08:31:01AM +0300, Mika Westerberg wrote: > On Mon, May 25, 2020 at 10:08:45PM +0300, Andy Shevchenko wrote: ... > > + dev_info(dev, "Applying ACPI interrupt quirk (GPIO %d)\n", pin); > > + return gpiod_to_irq(gpio_to_desc(pin)); > > You need to request the GPIO as well, I missed that from my example. How? I can't find a function to request GPIO by its descriptor in include/linux/gpio/*.
On Tue, May 26, 2020 at 04:11:19PM +0300, Andy Shevchenko wrote: > On Tue, May 26, 2020 at 08:31:01AM +0300, Mika Westerberg wrote: > > On Mon, May 25, 2020 at 10:08:45PM +0300, Andy Shevchenko wrote: > > ... > > > > + dev_info(dev, "Applying ACPI interrupt quirk (GPIO %d)\n", pin); > > > + return gpiod_to_irq(gpio_to_desc(pin)); > > > > You need to request the GPIO as well, I missed that from my example. > > How? I can't find a function to request GPIO by its descriptor in > include/linux/gpio/*. Not by descriptor but by number which you are already using here anyway. The function that does that is gpio_request(). I know we should use GPIO descriptors everywhere but this is a special case for a special hardware with a broken firmware, so IMHO it should be fine ;-) Once the legacy API is gets removed this whole hack can be removed as well and nobody will notice.
On Tue, May 26, 2020 at 3:11 PM Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote: > On Tue, May 26, 2020 at 08:31:01AM +0300, Mika Westerberg wrote: > > On Mon, May 25, 2020 at 10:08:45PM +0300, Andy Shevchenko wrote: > > ... > > > > + dev_info(dev, "Applying ACPI interrupt quirk (GPIO %d)\n", pin); > > > + return gpiod_to_irq(gpio_to_desc(pin)); > > > > You need to request the GPIO as well, I missed that from my example. > > How? I can't find a function to request GPIO by its descriptor in > include/linux/gpio/*. If a gpiochip need to request one of its own GPIOs it should use gpiochip_request_own_desc() but I don't know if you have all info at hand to use that in this driver. Yours, Linus Walleij
On Wed, May 27, 2020 at 07:43:28AM +0200, Linus Walleij wrote: > On Tue, May 26, 2020 at 3:11 PM Andy Shevchenko > <andriy.shevchenko@linux.intel.com> wrote: > > On Tue, May 26, 2020 at 08:31:01AM +0300, Mika Westerberg wrote: > > > On Mon, May 25, 2020 at 10:08:45PM +0300, Andy Shevchenko wrote: > > > > ... > > > > > > + dev_info(dev, "Applying ACPI interrupt quirk (GPIO %d)\n", pin); > > > > + return gpiod_to_irq(gpio_to_desc(pin)); > > > > > > You need to request the GPIO as well, I missed that from my example. > > > > How? I can't find a function to request GPIO by its descriptor in > > include/linux/gpio/*. > > If a gpiochip need to request one of its own GPIOs it should use > gpiochip_request_own_desc() It's not the case here.
diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c index 1fca8dd7824f..0d30f19782a2 100644 --- a/drivers/gpio/gpio-pca953x.c +++ b/drivers/gpio/gpio-pca953x.c @@ -10,6 +10,7 @@ #include <linux/acpi.h> #include <linux/bitmap.h> +#include <linux/dmi.h> #include <linux/gpio/driver.h> #include <linux/gpio/consumer.h> #include <linux/i2c.h> @@ -107,6 +108,62 @@ static const struct i2c_device_id pca953x_id[] = { }; MODULE_DEVICE_TABLE(i2c, pca953x_id); +#ifdef CONFIG_GPIO_PCA953X_IRQ +static const struct dmi_system_id pca953x_dmi_acpi_irq_info[] = { + { + /* + * On Intel Galileo Gen 2 board the IRQ pin of one of + * the I²C GPIO expanders, which has GpioInt() resource, + * is provided as an absolute number instead of being + * relative. Since first controller (gpio-sch.c) and + * second (gpio-dwapb.c) are at the fixed bases, we may + * safely refer to the number in the global space to get + * an IRQ out of it. + */ + .matches = { + DMI_EXACT_MATCH(DMI_BOARD_NAME, "GalileoGen2"), + }, + }, + {} +}; + +#ifdef CONFIG_ACPI +static acpi_status pca953x_acpi_get_pin(struct acpi_resource *ares, void *data) +{ + struct acpi_resource_gpio *agpio; + int *pin = data; + + if (!acpi_gpio_get_irq_resource(ares, &agpio)) + return AE_OK; + + *pin = agpio->pin_table[0]; + return AE_CTRL_TERMINATE; +} + +static int pca953x_acpi_find_pin(acpi_handle handle) +{ + int p = -ENOENT; + + acpi_walk_resources(handle, METHOD_NAME__CRS, pca953x_acpi_get_pin, &p); + return p; +} +#else +static inline int pca953x_acpi_find_pin(acpi_handle handle) { return -ENXIO; } +#endif + +static int pca953x_acpi_get_irq(struct device *dev) +{ + int pin; + + pin = pca953x_acpi_find_pin(ACPI_HANDLE(dev)); + if (pin < 0) + return pin; + + dev_info(dev, "Applying ACPI interrupt quirk (GPIO %d)\n", pin); + return gpiod_to_irq(gpio_to_desc(pin)); +} +#endif + static const struct acpi_device_id pca953x_acpi_ids[] = { { "INT3491", 16 | PCA953X_TYPE | PCA_LATCH_INT, }, { } @@ -750,8 +807,16 @@ static int pca953x_irq_setup(struct pca953x_chip *chip, int irq_base) struct irq_chip *irq_chip = &chip->irq_chip; DECLARE_BITMAP(reg_direction, MAX_LINE); DECLARE_BITMAP(irq_stat, MAX_LINE); + const struct dmi_system_id *id; int ret; + id = dmi_first_match(pca953x_dmi_acpi_irq_info); + if (id) { + ret = pca953x_acpi_get_irq(&client->dev); + if (ret > 0) + client->irq = ret; + } + if (!client->irq) return 0;
ACPI table on Intel Galileo Gen 2 has wrong pin number for IRQ resource of one of the I²C GPIO expanders. Since we know what that number is and luckily have GPIO bases fixed for SoC's controllers, we may use a simple DMI quirk to match the platform and retrieve GpioInt() pin on it for the expander in question. Suggested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- v2: did everything in the driver (Mika) drivers/gpio/gpio-pca953x.c | 65 +++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+)