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gpio: acpi: Override GPIO initialization flags
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This allows ACPI GPIO code to modify flags based on
ACPI GpioIo() / GpioInt() resources.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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Andy Shevchenko authored and Linus Walleij committed May 29, 2017
1 parent 2eca25a commit a31f5c3
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Showing 3 changed files with 67 additions and 6 deletions.
50 changes: 48 additions & 2 deletions drivers/gpio/gpiolib-acpi.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -448,6 +448,34 @@ acpi_gpio_to_gpiod_flags(const struct acpi_resource_gpio *agpio)
}
}

int
acpi_gpio_update_gpiod_flags(enum gpiod_flags *flags, enum gpiod_flags update)
{
int ret = 0;

/*
* Check if the BIOS has IoRestriction with explicitly set direction
* and update @flags accordingly. Otherwise use whatever caller asked
* for.
*/
if (update & GPIOD_FLAGS_BIT_DIR_SET) {
enum gpiod_flags diff = *flags ^ update;

/*
* Check if caller supplied incompatible GPIO initialization
* flags.
*
* Return %-EINVAL to notify that firmware has different
* settings and we are going to use them.
*/
if (((*flags & GPIOD_FLAGS_BIT_DIR_SET) && (diff & GPIOD_FLAGS_BIT_DIR_OUT)) ||
((*flags & GPIOD_FLAGS_BIT_DIR_OUT) && (diff & GPIOD_FLAGS_BIT_DIR_VAL)))
ret = -EINVAL;
*flags = update;
}
return ret;
}

struct acpi_gpio_lookup {
struct acpi_gpio_info info;
int index;
Expand Down Expand Up @@ -485,8 +513,11 @@ static int acpi_populate_gpio_lookup(struct acpi_resource *ares, void *data)
* - ACPI_ACTIVE_HIGH == GPIO_ACTIVE_HIGH
*/
if (lookup->info.gpioint) {
lookup->info.flags = GPIOD_IN;
lookup->info.polarity = agpio->polarity;
lookup->info.triggering = agpio->triggering;
} else {
lookup->info.flags = acpi_gpio_to_gpiod_flags(agpio);
}

}
Expand Down Expand Up @@ -613,13 +644,14 @@ static struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
struct gpio_desc *acpi_find_gpio(struct device *dev,
const char *con_id,
unsigned int idx,
enum gpiod_flags flags,
enum gpiod_flags *dflags,
enum gpio_lookup_flags *lookupflags)
{
struct acpi_device *adev = ACPI_COMPANION(dev);
struct acpi_gpio_info info;
struct gpio_desc *desc;
char propname[32];
int err;
int i;

/* Try first from _DSD */
Expand Down Expand Up @@ -650,14 +682,18 @@ struct gpio_desc *acpi_find_gpio(struct device *dev,
}

if (info.gpioint &&
(flags == GPIOD_OUT_LOW || flags == GPIOD_OUT_HIGH)) {
(*dflags == GPIOD_OUT_LOW || *dflags == GPIOD_OUT_HIGH)) {
dev_dbg(dev, "refusing GpioInt() entry when doing GPIOD_OUT_* lookup\n");
return ERR_PTR(-ENOENT);
}

if (info.polarity == GPIO_ACTIVE_LOW)
*lookupflags |= GPIO_ACTIVE_LOW;

err = acpi_gpio_update_gpiod_flags(dflags, info.flags);
if (err)
dev_dbg(dev, "Override GPIO initialization flags\n");

return desc;
}

Expand Down Expand Up @@ -711,12 +747,16 @@ struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
* used to translate from the GPIO offset in the resource to the Linux IRQ
* number.
*
* The function is idempotent, though each time it runs it will configure GPIO
* pin direction according to the flags in GpioInt resource.
*
* Return: Linux IRQ number (>%0) on success, negative errno on failure.
*/
int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index)
{
int idx, i;
unsigned int irq_flags;
int ret;

for (i = 0, idx = 0; idx <= index; i++) {
struct acpi_gpio_info info;
Expand All @@ -729,6 +769,7 @@ int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index)
return PTR_ERR(desc);

if (info.gpioint && idx++ == index) {
char label[32];
int irq;

if (IS_ERR(desc))
Expand All @@ -738,6 +779,11 @@ int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index)
if (irq < 0)
return irq;

snprintf(label, sizeof(label), "GpioInt() %d", index);
ret = gpiod_configure_flags(desc, label, 0, info.flags);
if (ret < 0)
return ret;

irq_flags = acpi_dev_get_irq_type(info.triggering,
info.polarity);

Expand Down
8 changes: 6 additions & 2 deletions drivers/gpio/gpiolib.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3286,7 +3286,7 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
desc = of_find_gpio(dev, con_id, idx, &lookupflags);
} else if (ACPI_COMPANION(dev)) {
dev_dbg(dev, "using ACPI for GPIO lookup\n");
desc = acpi_find_gpio(dev, con_id, idx, flags, &lookupflags);
desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
}
}

Expand Down Expand Up @@ -3367,8 +3367,12 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
struct acpi_gpio_info info;

desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
if (!IS_ERR(desc))
if (!IS_ERR(desc)) {
active_low = info.polarity == GPIO_ACTIVE_LOW;
ret = acpi_gpio_update_gpiod_flags(&dflags, info.flags);
if (ret)
pr_debug("Override GPIO initialization flags\n");
}
}

if (IS_ERR(desc))
Expand Down
15 changes: 13 additions & 2 deletions drivers/gpio/gpiolib.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -75,11 +75,13 @@ struct gpio_device {

/**
* struct acpi_gpio_info - ACPI GPIO specific information
* @flags: GPIO initialization flags
* @gpioint: if %true this GPIO is of type GpioInt otherwise type is GpioIo
* @polarity: interrupt polarity as provided by ACPI
* @triggering: triggering type as provided by ACPI
*/
struct acpi_gpio_info {
enum gpiod_flags flags;
bool gpioint;
int polarity;
int triggering;
Expand Down Expand Up @@ -121,10 +123,13 @@ void acpi_gpiochip_remove(struct gpio_chip *chip);
void acpi_gpiochip_request_interrupts(struct gpio_chip *chip);
void acpi_gpiochip_free_interrupts(struct gpio_chip *chip);

int acpi_gpio_update_gpiod_flags(enum gpiod_flags *flags,
enum gpiod_flags update);

struct gpio_desc *acpi_find_gpio(struct device *dev,
const char *con_id,
unsigned int idx,
enum gpiod_flags flags,
enum gpiod_flags *dflags,
enum gpio_lookup_flags *lookupflags);
struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
const char *propname, int index,
Expand All @@ -143,9 +148,15 @@ acpi_gpiochip_request_interrupts(struct gpio_chip *chip) { }
static inline void
acpi_gpiochip_free_interrupts(struct gpio_chip *chip) { }

static inline int
acpi_gpio_update_gpiod_flags(enum gpiod_flags *flags, enum gpiod_flags update)
{
return 0;
}

static inline struct gpio_desc *
acpi_find_gpio(struct device *dev, const char *con_id,
unsigned int idx, enum gpiod_flags flags,
unsigned int idx, enum gpiod_flags *dflags,
enum gpio_lookup_flags *lookupflags)
{
return ERR_PTR(-ENOENT);
Expand Down

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