[linux-yocto] [PATCH 27/29] gpio-pca953x: add "drive" property.
Paul Gortmaker
paul.gortmaker at windriver.com
Sun Feb 7 14:46:49 PST 2016
[[linux-yocto] [PATCH 27/29] gpio-pca953x: add "drive" property.] On 05/02/2016 (Fri 06:53) Saul Wold wrote:
> From: Ismo Puustinen <ismo.puustinen at intel.com>
>
> Galileo gen 2 has support for setting GPIO modes. Expose these
> properties through the GPIO sysfs interface. This approach is bit hacky,
> since it changes the interface semantics.
>
> The original patch was by Josef Ahmad <josef.ahmad at linux.intel.com> and
> made on top of kernel 3.8.
>
> Signed-off-by: Ismo Puustinen <ismo.puustinen at intel.com>
> Signed-off-by: Saul Wold <sgw at linux.intel.com>
Upstream status of this one is ..... ?
P.
--
> ---
> drivers/gpio/gpio-pca953x.c | 57 +++++++++++++++++++++++++++----
> drivers/gpio/gpiolib-sysfs.c | 78 +++++++++++++++++++++++++++++++++++++++++++
> drivers/gpio/gpiolib.c | 18 ++++++++++
> drivers/gpio/gpiolib.h | 7 +++-
> include/asm-generic/gpio.h | 5 +++
> include/linux/gpio.h | 10 ++++++
> include/linux/gpio/consumer.h | 11 ++++++
> include/linux/gpio/driver.h | 2 ++
> 8 files changed, 180 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
> index 0227cde..8f49bd6 100644
> --- a/drivers/gpio/gpio-pca953x.c
> +++ b/drivers/gpio/gpio-pca953x.c
> @@ -39,6 +39,9 @@
> #define PCA957X_MSK 6
> #define PCA957X_INTS 7
>
> +#define PCA953X_PUPD_EN 35
> +#define PCA953X_PUPD_SEL 36
> +
> #define PCA_GPIO_MASK 0x00FF
> #define PCA_INT 0x0100
> #define PCA953X_TYPE 0x1000
> @@ -374,6 +377,43 @@ exit:
> mutex_unlock(&chip->i2c_lock);
> }
>
> +static int pca953x_gpio_set_drive(struct gpio_chip *gc,
> + unsigned off, unsigned mode)
> +{
> + struct pca953x_chip *chip;
> + int ret = 0;
> + int val;
> +
> + chip = container_of(gc, struct pca953x_chip, gpio_chip);
> +
> + if (chip->chip_type != PCA953X_TYPE)
> + return -EINVAL;
> +
> + mutex_lock(&chip->i2c_lock);
> +
> + switch (mode) {
> + case GPIOF_DRIVE_PULLUP:
> + ret = pca953x_write_single(chip, PCA953X_PUPD_EN, 1, off) ||
> + pca953x_write_single(chip, PCA953X_PUPD_SEL, 1, off);
> + break;
> + case GPIOF_DRIVE_PULLDOWN:
> + ret = pca953x_write_single(chip, PCA953X_PUPD_EN, 1, off) ||
> + pca953x_write_single(chip, PCA953X_PUPD_SEL, 0, off);
> + break;
> + case GPIOF_DRIVE_STRONG:
> + case GPIOF_DRIVE_HIZ:
> + ret = pca953x_read_single(chip, PCA953X_PUPD_EN, &val, off) ||
> + pca953x_write_single(chip, PCA953X_PUPD_EN, 0, off) ||
> + pca953x_write_single(chip, PCA953X_PUPD_SEL, val, off);
> + break;
> + default:
> + ret = -EINVAL;
> + }
> +
> + mutex_unlock(&chip->i2c_lock);
> + return ret;
> +}
> +
> static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
> {
> struct gpio_chip *gc;
> @@ -392,6 +432,9 @@ static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
> gc->dev = &chip->client->dev;
> gc->owner = THIS_MODULE;
> gc->names = chip->names;
> +
> + if (chip->chip_type == PCA953X_TYPE)
> + gc->set_drive = pca953x_gpio_set_drive;
> }
>
> #ifdef CONFIG_GPIO_PCA953X_IRQ
> @@ -548,7 +591,7 @@ static irqreturn_t pca953x_irq_handler(int irq, void *devid)
> }
>
> static int pca953x_irq_setup(struct pca953x_chip *chip,
> - int irq_base)
> + int irq_base)
> {
> struct i2c_client *client = chip->client;
> int ret, i, offset = 0;
> @@ -591,10 +634,10 @@ static int pca953x_irq_setup(struct pca953x_chip *chip,
> }
>
> ret = gpiochip_irqchip_add(&chip->gpio_chip,
> - &pca953x_irq_chip,
> - irq_base,
> - handle_simple_irq,
> - IRQ_TYPE_NONE);
> + &pca953x_irq_chip,
> + irq_base,
> + handle_simple_irq,
> + IRQ_TYPE_NONE);
> if (ret) {
> dev_err(&client->dev,
> "could not connect irqchip to gpiochip\n");
> @@ -607,7 +650,7 @@ static int pca953x_irq_setup(struct pca953x_chip *chip,
>
> #else /* CONFIG_GPIO_PCA953X_IRQ */
> static int pca953x_irq_setup(struct pca953x_chip *chip,
> - int irq_base)
> + int irq_base)
> {
> struct i2c_client *client = chip->client;
>
> @@ -628,7 +671,7 @@ static int device_pca953x_init(struct pca953x_chip *chip, u32 invert)
> goto out;
>
> ret = pca953x_read_regs(chip, PCA953X_DIRECTION,
> - chip->reg_direction);
> + chip->reg_direction);
> if (ret)
> goto out;
>
> diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
> index af3bc7a..4f90f69 100644
> --- a/drivers/gpio/gpiolib-sysfs.c
> +++ b/drivers/gpio/gpiolib-sysfs.c
> @@ -6,6 +6,7 @@
> #include <linux/gpio/driver.h>
> #include <linux/interrupt.h>
> #include <linux/kdev_t.h>
> +#include <linux/gpio.h>
>
> #include "gpiolib.h"
>
> @@ -356,6 +357,82 @@ static ssize_t gpio_active_low_store(struct device *dev,
> static DEVICE_ATTR(active_low, 0644,
> gpio_active_low_show, gpio_active_low_store);
>
> +
> +static ssize_t gpio_drive_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + const struct gpio_desc *desc = dev_get_drvdata(dev);
> + ssize_t status;
> +
> + mutex_lock(&sysfs_lock);
> +
> + if (!test_bit(FLAG_EXPORT, &desc->flags)) {
> + status = -EIO;
> + } else {
> + if (test_bit(FLAG_PULLUP, &desc->flags))
> + status = sprintf(buf, "pullup\n");
> + else if (test_bit(FLAG_PULLDOWN, &desc->flags))
> + status = sprintf(buf, "pulldown\n");
> + else if (test_bit(FLAG_STRONG, &desc->flags))
> + status = sprintf(buf, "strong\n");
> + else if (test_bit(FLAG_HIZ, &desc->flags))
> + status = sprintf(buf, "hiz\n");
> + else
> + status = -EINVAL;
> + }
> +
> + mutex_unlock(&sysfs_lock);
> + return status;
> +}
> +
> +static ssize_t gpio_drive_store(struct device *dev,
> + struct device_attribute *attr, const char *buf, size_t size)
> +{
> + struct gpio_desc *desc = dev_get_drvdata(dev);
> + ssize_t status;
> +
> + mutex_lock(&sysfs_lock);
> +
> + if (!test_bit(FLAG_EXPORT, &desc->flags))
> + status = -EIO;
> + else {
> + if (sysfs_streq(buf, "pullup")) {
> + status = gpiod_set_drive(desc, GPIOF_DRIVE_PULLUP);
> + if (!status) {
> + desc->flags &= ~GPIO_DRIVE_MASK;
> + set_bit(FLAG_PULLUP, &desc->flags);
> + }
> + } else if (sysfs_streq(buf, "pulldown")) {
> + status = gpiod_set_drive(desc, GPIOF_DRIVE_PULLDOWN);
> + if (!status) {
> + desc->flags &= ~GPIO_DRIVE_MASK;
> + set_bit(FLAG_PULLDOWN, &desc->flags);
> + }
> + } else if (sysfs_streq(buf, "strong")) {
> + status = gpiod_set_drive(desc, GPIOF_DRIVE_STRONG);
> + if (!status) {
> + desc->flags &= ~GPIO_DRIVE_MASK;
> + set_bit(FLAG_STRONG, &desc->flags);
> + }
> + } else if (sysfs_streq(buf, "hiz")) {
> + status = gpiod_set_drive(desc, GPIOF_DRIVE_HIZ);
> + if (!status) {
> + desc->flags &= ~GPIO_DRIVE_MASK;
> + set_bit(FLAG_HIZ, &desc->flags);
> + }
> + } else {
> + status = -EINVAL;
> + }
> + }
> +
> + mutex_unlock(&sysfs_lock);
> + return status ? : size;
> +}
> +
> +static const DEVICE_ATTR(drive, 0644,
> + gpio_drive_show, gpio_drive_store);
> +
> +
> static umode_t gpio_is_visible(struct kobject *kobj, struct attribute *attr,
> int n)
> {
> @@ -382,6 +459,7 @@ static struct attribute *gpio_attrs[] = {
> &dev_attr_edge.attr,
> &dev_attr_value.attr,
> &dev_attr_active_low.attr,
> + &dev_attr_drive.attr,
> NULL,
> };
>
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index 6bc612b..038159b 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -1127,6 +1127,24 @@ int gpiod_is_active_low(const struct gpio_desc *desc)
> }
> EXPORT_SYMBOL_GPL(gpiod_is_active_low);
>
> +int gpiod_set_drive(struct gpio_desc *desc, unsigned mode)
> +{
> + unsigned long flags;
> + struct gpio_chip *chip;
> +
> + chip = desc->chip;
> + if (!chip || !chip->set || !chip->set_drive)
> + goto fail;
> +
> + might_sleep_if(chip->can_sleep);
> +
> + return chip->set_drive(chip, gpio_chip_hwgpio(desc), mode);
> +
> +fail:
> + return -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(gpiod_set_drive);
> +
> /* I/O calls are only valid after configuration completed; the relevant
> * "is this a valid GPIO" error checks should already have been done.
> *
> diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
> index 594b179..2ffc2e6 100644
> --- a/drivers/gpio/gpiolib.h
> +++ b/drivers/gpio/gpiolib.h
> @@ -91,12 +91,17 @@ struct gpio_desc {
> #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
> #define FLAG_SYSFS_DIR 10 /* show sysfs direction attribute */
> #define FLAG_IS_HOGGED 11 /* GPIO is hogged */
> +#define FLAG_PULLUP 12 /* Gpio drive is resistive pullup */
> +#define FLAG_PULLDOWN 13 /* Gpio drive is resistive pulldown */
> +#define FLAG_STRONG 14 /* Gpio drive is strong (fast output) */
> +#define FLAG_HIZ 15 /* Gpio drive is Hi-Z (input) */
>
> #define ID_SHIFT 16 /* add new flags before this one */
>
> #define GPIO_FLAGS_MASK ((1 << ID_SHIFT) - 1)
> #define GPIO_TRIGGER_MASK (BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE))
> -
> +#define GPIO_DRIVE_MASK (BIT(FLAG_PULLUP) | BIT(FLAG_PULLDOWN) \
> + | BIT(FLAG_STRONG) | BIT(FLAG_HIZ))
> const char *label;
> };
>
> diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
> index 9bb0d11..21c9497 100644
> --- a/include/asm-generic/gpio.h
> +++ b/include/asm-generic/gpio.h
> @@ -76,6 +76,11 @@ static inline int gpio_set_debounce(unsigned gpio, unsigned debounce)
> return gpiod_set_debounce(gpio_to_desc(gpio), debounce);
> }
>
> +static inline int gpio_set_drive(unsigned gpio, unsigned mode)
> +{
> + return gpiod_set_drive(gpio_to_desc(gpio), mode);
> +}
> +
> static inline int gpio_get_value_cansleep(unsigned gpio)
> {
> return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio));
> diff --git a/include/linux/gpio.h b/include/linux/gpio.h
> index ab81339..c22f1f6 100644
> --- a/include/linux/gpio.h
> +++ b/include/linux/gpio.h
> @@ -30,6 +30,11 @@
> #define GPIOF_EXPORT_DIR_FIXED (GPIOF_EXPORT)
> #define GPIOF_EXPORT_DIR_CHANGEABLE (GPIOF_EXPORT | GPIOF_EXPORT_CHANGEABLE)
>
> +#define GPIOF_DRIVE_PULLUP (1 << 7)
> +#define GPIOF_DRIVE_PULLDOWN (1 << 8)
> +#define GPIOF_DRIVE_STRONG (1 << 9)
> +#define GPIOF_DRIVE_HIZ (1 << 10)
> +
> /**
> * struct gpio - a structure describing a GPIO with configuration
> * @gpio: the GPIO number
> @@ -148,6 +153,11 @@ static inline int gpio_set_debounce(unsigned gpio, unsigned debounce)
> return -ENOSYS;
> }
>
> +static inline int gpio_set_drive(unsigned gpio, unsigned mode)
> +{
> + return -ENOSYS;
> +}
> +
> static inline int gpio_get_value(unsigned gpio)
> {
> /* GPIO can never have been requested or set as {in,out}put */
> diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
> index da04265..ecdbc74 100644
> --- a/include/linux/gpio/consumer.h
> +++ b/include/linux/gpio/consumer.h
> @@ -121,6 +121,8 @@ void gpiod_set_raw_array_cansleep(unsigned int array_size,
>
> int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce);
>
> +int gpiod_set_drive(struct gpio_desc *desc, unsigned mode);
> +
> int gpiod_is_active_low(const struct gpio_desc *desc);
> int gpiod_cansleep(const struct gpio_desc *desc);
>
> @@ -375,6 +377,15 @@ static inline int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
> return -ENOSYS;
> }
>
> +
> +static inline int gpiod_set_drive(unsigned gpio, unsigned mode)
> +{
> + /* GPIO can never have been requested */
> + WARN_ON(1);
> + return -ENOSYS;
> +}
> +
> +
> static inline int gpiod_is_active_low(const struct gpio_desc *desc)
> {
> /* GPIO can never have been requested */
> diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
> index f1b3659..2f19b34 100644
> --- a/include/linux/gpio/driver.h
> +++ b/include/linux/gpio/driver.h
> @@ -97,6 +97,8 @@ struct gpio_chip {
> int (*set_debounce)(struct gpio_chip *chip,
> unsigned offset,
> unsigned debounce);
> + int (*set_drive)(struct gpio_chip *chip,
> + unsigned offset, unsigned mode);
>
> int (*to_irq)(struct gpio_chip *chip,
> unsigned offset);
> --
> 2.5.0
>
> --
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