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Date: Sat, 12 Feb 2011 18:49:57 +0100
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Subject: Re: [PATCH] leds-pca9532: Add gpio capability v3 (RESEND)
From: Joachim Eastwood <manabian@gmail.com>
To: linux-kernel@vger.kernel.org, rpurdie@rpsys.net, riku.voipio@iki.fi,
        akpm@linux-foundation.org, richard.purdie@linux-foundation.org
Cc: joachim.eastwood@jotron.com, w.sang@pengutronix.de,
        hartleys@visionengravers.com
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Trying alternate email for Richard Purdie and adding Andrew Morton.

patchwork: https://patchwork.kernel.org/patch/523771/

Patch now also reviewed by Hartley Sweeten. (Thanks Hartley)

On Tue, Feb 1, 2011 at 8:40 PM, Joachim  Eastwood <manabian@gmail.com> wrote:
> Hello,
>
> The patch below allows unused leds on pca9532 to be used as gpio. The
> board I am working on now has no less than 6 pca9532 chips. One chips
> is used for only leds, one has 14 leds and 2 gpio and the rest of the
> chips are gpio only.
>
> There is also one board in mainline which could use this capabilty;
> arch/arm/mach-iop32x/n2100.c
> ?232 ? ? ? ? { ? ? ? .type = PCA9532_TYPE_NONE }, /* power OFF gpio */
> ?233 ? ? ? ? { ? ? ? .type = PCA9532_TYPE_NONE }, /* reset gpio */
>
> This patch defines a new pin type, PCA9532_TYPE_GPIO, and registers a
> gpiochip if any pin has this type set. The gpio will registers all
> chip pins but will filter on gpio_request.
>
> Changes in v3:
> * Fixed direction_output funtion, thanks to H Hartley Sweeten
> * direction_input now calles set_value as direction_output
> * Instructions in Kconfig
>
> Tested on custom ARM board.
>
> -------------------------------------------------------------------
> ? ?[leds-pca9532] Add gpio capability
>
> ? ?Pins not used for leds can now be used as gpio by setting pin type as
> ? ?PCA9532_TYPE_GPIO and defining a gpio_base in platform data.
>
> ? ?Signed-off-by: Joachim Eastwood <joachim.eastwood@jotron.com>
> ? ?Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
> ---
> ?drivers/leds/Kconfig ? ? ? ? | ? 10 ++++
> ?drivers/leds/leds-pca9532.c ?| ?111 ++++++++++++++++++++++++++++++++++++++++-
> ?include/linux/leds-pca9532.h | ? ?3 +-
> ?3 files changed, 120 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index 6f190f4..525c517 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -152,6 +152,16 @@ config LEDS_PCA9532
> ? ? ? ? ?LED controller. It is generally only useful
> ? ? ? ? ?as a platform driver
>
> +config LEDS_PCA9532_GPIO
> + ? ? ? bool "Enable GPIO support for PCA9532"
> + ? ? ? depends on LEDS_PCA9532
> + ? ? ? depends on GPIOLIB
> + ? ? ? help
> + ? ? ? ? Allow unused pins on PCA9532 to be used as gpio.
> +
> + ? ? ? ? To use a pin as gpio pca9532_type in pca9532_platform data needs to
> + ? ? ? ? set to PCA9532_TYPE_GPIO.
> +
> ?config LEDS_GPIO
> ? ? ? ?tristate "LED Support for GPIO connected LEDs"
> ? ? ? ?depends on LEDS_CLASS
> diff --git a/drivers/leds/leds-pca9532.c b/drivers/leds/leds-pca9532.c
> index afac338..ad008bb 100644
> --- a/drivers/leds/leds-pca9532.c
> +++ b/drivers/leds/leds-pca9532.c
> @@ -19,7 +19,9 @@
> ?#include <linux/mutex.h>
> ?#include <linux/workqueue.h>
> ?#include <linux/leds-pca9532.h>
> +#include <linux/gpio.h>
>
> +#define PCA9532_REG_INPUT(i) ((i)/8)
> ?#define PCA9532_REG_PSC(i) (0x2+(i)*2)
> ?#define PCA9532_REG_PWM(i) (0x3+(i)*2)
> ?#define PCA9532_REG_LS0 ?0x6
> @@ -34,6 +36,7 @@ struct pca9532_data {
> ? ? ? ?struct mutex update_lock;
> ? ? ? ?struct input_dev *idev;
> ? ? ? ?struct work_struct work;
> + ? ? ? struct gpio_chip gpio;
> ? ? ? ?u8 pwm[2];
> ? ? ? ?u8 psc[2];
> ?};
> @@ -200,16 +203,68 @@ static void pca9532_led_work(struct work_struct *work)
> ? ? ? ?pca9532_setled(led);
> ?}
>
> -static void pca9532_destroy_devices(struct pca9532_data *data, int n_devs)
> +#ifdef CONFIG_LEDS_PCA9532_GPIO
> +static int pca9532_gpio_request_pin(struct gpio_chip *gc, unsigned offset)
> +{
> + ? ? ? struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
> + ? ? ? struct pca9532_led *led = &data->leds[offset];
> +
> + ? ? ? if (led->type == PCA9532_TYPE_GPIO)
> + ? ? ? ? ? ? ? return 0;
> +
> + ? ? ? return -EBUSY;
> +}
> +
> +static void pca9532_gpio_set_value(struct gpio_chip *gc, unsigned
> offset, int val)
> +{
> + ? ? ? struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
> + ? ? ? struct pca9532_led *led = &data->leds[offset];
> +
> + ? ? ? if (val)
> + ? ? ? ? ? ? ? led->state = PCA9532_ON;
> + ? ? ? else
> + ? ? ? ? ? ? ? led->state = PCA9532_OFF;
> +
> + ? ? ? pca9532_setled(led);
> +}
> +
> +static int pca9532_gpio_get_value(struct gpio_chip *gc, unsigned offset)
> +{
> + ? ? ? struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
> + ? ? ? unsigned char reg;
> +
> + ? ? ? reg = i2c_smbus_read_byte_data(data->client, PCA9532_REG_INPUT(offset));
> +
> + ? ? ? return !!(reg & (1 << (offset % 8)));
> +}
> +
> +static int pca9532_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
> +{
> + ? ? ? /* To use as input ensure pin is not driven */
> + ? ? ? pca9532_gpio_set_value(gc, offset, 0);
> +
> + ? ? ? return 0;
> +}
> +
> +static int pca9532_gpio_direction_output(struct gpio_chip *gc,
> unsigned offset, int val)
> +{
> + ? ? ? pca9532_gpio_set_value(gc, offset, val);
> +
> + ? ? ? return 0;
> +}
> +#endif /* CONFIG_LEDS_PCA9532_GPIO */
> +
> +static int pca9532_destroy_devices(struct pca9532_data *data, int n_devs)
> ?{
> ? ? ? ?int i = n_devs;
>
> ? ? ? ?if (!data)
> - ? ? ? ? ? ? ? return;
> + ? ? ? ? ? ? ? return -EINVAL;
>
> ? ? ? ?while (--i >= 0) {
> ? ? ? ? ? ? ? ?switch (data->leds[i].type) {
> ? ? ? ? ? ? ? ?case PCA9532_TYPE_NONE:
> + ? ? ? ? ? ? ? case PCA9532_TYPE_GPIO:
> ? ? ? ? ? ? ? ? ? ? ? ?break;
> ? ? ? ? ? ? ? ?case PCA9532_TYPE_LED:
> ? ? ? ? ? ? ? ? ? ? ? ?led_classdev_unregister(&data->leds[i].ldev);
> @@ -224,12 +279,26 @@ static void pca9532_destroy_devices(struct
> pca9532_data *data, int n_devs)
> ? ? ? ? ? ? ? ? ? ? ? ?break;
> ? ? ? ? ? ? ? ?}
> ? ? ? ?}
> +
> +#ifdef CONFIG_LEDS_PCA9532_GPIO
> + ? ? ? if (data->gpio.dev) {
> + ? ? ? ? ? ? ? int err = gpiochip_remove(&data->gpio);
> + ? ? ? ? ? ? ? if (err) {
> + ? ? ? ? ? ? ? ? ? ? ? dev_err(&data->client->dev, "%s failed, %d\n",
> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? "gpiochip_remove()", err);
> + ? ? ? ? ? ? ? ? ? ? ? return err;
> + ? ? ? ? ? ? ? }
> + ? ? ? }
> +#endif
> +
> + ? ? ? return 0;
> ?}
>
> ?static int pca9532_configure(struct i2c_client *client,
> ? ? ? ?struct pca9532_data *data, struct pca9532_platform_data *pdata)
> ?{
> ? ? ? ?int i, err = 0;
> + ? ? ? int gpios = 0;
>
> ? ? ? ?for (i = 0; i < 2; i++) {
> ? ? ? ? ? ? ? ?data->pwm[i] = pdata->pwm[i];
> @@ -249,6 +318,9 @@ static int pca9532_configure(struct i2c_client *client,
> ? ? ? ? ? ? ? ?switch (led->type) {
> ? ? ? ? ? ? ? ?case PCA9532_TYPE_NONE:
> ? ? ? ? ? ? ? ? ? ? ? ?break;
> + ? ? ? ? ? ? ? case PCA9532_TYPE_GPIO:
> + ? ? ? ? ? ? ? ? ? ? ? gpios++;
> + ? ? ? ? ? ? ? ? ? ? ? break;
> ? ? ? ? ? ? ? ?case PCA9532_TYPE_LED:
> ? ? ? ? ? ? ? ? ? ? ? ?led->state = pled->state;
> ? ? ? ? ? ? ? ? ? ? ? ?led->name = pled->name;
> @@ -297,6 +369,34 @@ static int pca9532_configure(struct i2c_client *client,
> ? ? ? ? ? ? ? ? ? ? ? ?break;
> ? ? ? ? ? ? ? ?}
> ? ? ? ?}
> +
> +#ifdef CONFIG_LEDS_PCA9532_GPIO
> + ? ? ? if (gpios) {
> + ? ? ? ? ? ? ? data->gpio.label = "gpio-pca9532";
> + ? ? ? ? ? ? ? data->gpio.direction_input = pca9532_gpio_direction_input;
> + ? ? ? ? ? ? ? data->gpio.direction_output = pca9532_gpio_direction_output;
> + ? ? ? ? ? ? ? data->gpio.set = pca9532_gpio_set_value;
> + ? ? ? ? ? ? ? data->gpio.get = pca9532_gpio_get_value;
> + ? ? ? ? ? ? ? data->gpio.request = pca9532_gpio_request_pin;
> + ? ? ? ? ? ? ? data->gpio.can_sleep = 1;
> + ? ? ? ? ? ? ? data->gpio.base = pdata->gpio_base;
> + ? ? ? ? ? ? ? data->gpio.ngpio = 16;
> + ? ? ? ? ? ? ? data->gpio.dev = &client->dev;
> + ? ? ? ? ? ? ? data->gpio.owner = THIS_MODULE;
> +
> + ? ? ? ? ? ? ? err = gpiochip_add(&data->gpio);
> + ? ? ? ? ? ? ? if (err) {
> + ? ? ? ? ? ? ? ? ? ? ? /* Use data->gpio.dev as a flag for freeing gpiochip */
> + ? ? ? ? ? ? ? ? ? ? ? data->gpio.dev = NULL;
> + ? ? ? ? ? ? ? ? ? ? ? dev_warn(&client->dev, "could not add gpiochip\n");
> + ? ? ? ? ? ? ? } else {
> + ? ? ? ? ? ? ? ? ? ? ? dev_info(&client->dev, "gpios %i...%i\n",
> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? data->gpio.base, data->gpio.base +
> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? data->gpio.ngpio - 1);
> + ? ? ? ? ? ? ? }
> + ? ? ? }
> +#endif
> +
> ? ? ? ?return 0;
>
> ?exit:
> @@ -337,7 +437,12 @@ static int pca9532_probe(struct i2c_client *client,
> ?static int pca9532_remove(struct i2c_client *client)
> ?{
> ? ? ? ?struct pca9532_data *data = i2c_get_clientdata(client);
> - ? ? ? pca9532_destroy_devices(data, 16);
> + ? ? ? int err;
> +
> + ? ? ? err = pca9532_destroy_devices(data, 16);
> + ? ? ? if (err)
> + ? ? ? ? ? ? ? return err;
> +
> ? ? ? ?kfree(data);
> ? ? ? ?return 0;
> ?}
> diff --git a/include/linux/leds-pca9532.h b/include/linux/leds-pca9532.h
> index f158eb1..b8d6fff 100644
> --- a/include/linux/leds-pca9532.h
> +++ b/include/linux/leds-pca9532.h
> @@ -25,7 +25,7 @@ enum pca9532_state {
> ?};
>
> ?enum pca9532_type { PCA9532_TYPE_NONE, PCA9532_TYPE_LED,
> - ? ? ? PCA9532_TYPE_N2100_BEEP };
> + ? ? ? PCA9532_TYPE_N2100_BEEP, PCA9532_TYPE_GPIO };
>
> ?struct pca9532_led {
> ? ? ? ?u8 id;
> @@ -41,6 +41,7 @@ struct pca9532_platform_data {
> ? ? ? ?struct pca9532_led leds[16];
> ? ? ? ?u8 pwm[2];
> ? ? ? ?u8 psc[2];
> + ? ? ? int gpio_base;
> ?};
>
> ?#endif /* __LINUX_PCA9532_H */
>
--
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