On Thu, Jul 25, 2013 at 10:16 AM, Mark A. Greer <mgreer@xxxxxxxxxxxxxxx> wrote:
> From: "Mark A. Greer" <mgreer@xxxxxxxxxxxxxxx>
>
> Add hardware blinking support to the pca9633 driver.
>
> NOTE: Hardware blinking violates the leds infrastructure
> driver interface since the hardware only supports
> blinking all LEDs with the same delay_on/delay_off
> rates. That is, only the LEDs that are set to blink
> will actually blink but all LEDs that are set to blink
> will blink in identical fashion. The delay_on/delay_off
> values of the last LED that is set to blink will be used
> for all of the blinking LEDs. If the hardware doesn't
> support the requested blinking pattern, a default of
> 500ms on and off will be used.
>
> Hardware blinking is disabled by default but can be enabled
> by setting the 'blink_type' member in the platform_data
> struct to 'PCA9633_HW_BLINK' or by adding the 'nxp,hw-blink'
> property to the DTS.
>
> Signed-off-by: Mark A. Greer <mgreer@xxxxxxxxxxxxxxx>
Looks good to me, I merged it into my tree.
Thanks,
-Bryan
> ---
> Changes from v2:
> - Hardware blinking now optional via platform data and DTS.
> - Commit description and source comments extendd to describe
> how to turn hardware blinking on.
>
> Changes from v1:
> - Minor commit description edit.
> - Added a copy of the NOTE section from commit description
> to the comments at the beginning of the source file.
>
> Applies to linux-leds/devel
>
> Documentation/devicetree/bindings/leds/pca9633.txt | 1 +
> drivers/leds/leds-pca9633.c | 136 ++++++++++++++++++++-
> include/linux/platform_data/leds-pca9633.h | 6 +
> 3 files changed, 139 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/leds/pca9633.txt b/Documentation/devicetree/bindings/leds/pca9633.txt
> index 8140512..6d9e1a9 100644
> --- a/Documentation/devicetree/bindings/leds/pca9633.txt
> +++ b/Documentation/devicetree/bindings/leds/pca9633.txt
> @@ -5,6 +5,7 @@ Required properties:
>
> Optional properties:
> - nxp,totem-pole : use totem pole (push-pull) instead of default open-drain
> +- nxp,hw-blink : use hardware blinking instead of software blinking
>
> Each led is represented as a sub-node of the nxp,pca9633 device.
>
> diff --git a/drivers/leds/leds-pca9633.c b/drivers/leds/leds-pca9633.c
> index 90935e4..7a75707 100644
> --- a/drivers/leds/leds-pca9633.c
> +++ b/drivers/leds/leds-pca9633.c
> @@ -11,6 +11,15 @@
> *
> * LED driver for the PCA9633 I2C LED driver (7-bit slave address 0x62)
> *
> + * Note that hardware blinking violates the leds infrastructure driver
> + * interface since the hardware only supports blinking all LEDs with the
> + * same delay_on/delay_off rates. That is, only the LEDs that are set to
> + * blink will actually blink but all LEDs that are set to blink will blink
> + * in identical fashion. The delay_on/delay_off values of the last LED
> + * that is set to blink will be used for all of the blinking LEDs.
> + * Hardware blinking is disabled by default but can be enabled by setting
> + * the 'blink_type' member in the platform_data struct to 'PCA9633_HW_BLINK'
> + * or by adding the 'nxp,hw-blink' property to the DTS.
> */
>
> #include <linux/module.h>
> @@ -31,30 +40,44 @@
> #define PCA9633_LED_PWM 0x2 /* Controlled through PWM */
> #define PCA9633_LED_GRP_PWM 0x3 /* Controlled through PWM/GRPPWM */
>
> +#define PCA9633_MODE2_DMBLNK 0x20 /* Enable blinking */
> +
> #define PCA9633_MODE1 0x00
> #define PCA9633_MODE2 0x01
> #define PCA9633_PWM_BASE 0x02
> +#define PCA9633_GRPPWM 0x06
> +#define PCA9633_GRPFREQ 0x07
> #define PCA9633_LEDOUT 0x08
>
> +/* Total blink period in milliseconds */
> +#define PCA9632_BLINK_PERIOD_MIN 42
> +#define PCA9632_BLINK_PERIOD_MAX 10667
> +
> static const struct i2c_device_id pca9633_id[] = {
> { "pca9633", 0 },
> { }
> };
> MODULE_DEVICE_TABLE(i2c, pca9633_id);
>
> +enum pca9633_cmd {
> + BRIGHTNESS_SET,
> + BLINK_SET,
> +};
> +
> struct pca9633_led {
> struct i2c_client *client;
> struct work_struct work;
> enum led_brightness brightness;
> struct led_classdev led_cdev;
> int led_num; /* 0 .. 3 potentially */
> + enum pca9633_cmd cmd;
> char name[32];
> + u8 gdc;
> + u8 gfrq;
> };
>
> -static void pca9633_led_work(struct work_struct *work)
> +static void pca9633_brightness_work(struct pca9633_led *pca9633)
> {
> - struct pca9633_led *pca9633 = container_of(work,
> - struct pca9633_led, work);
> u8 ledout = i2c_smbus_read_byte_data(pca9633->client, PCA9633_LEDOUT);
> int shift = 2 * pca9633->led_num;
> u8 mask = 0x3 << shift;
> @@ -78,6 +101,43 @@ static void pca9633_led_work(struct work_struct *work)
> }
> }
>
> +static void pca9633_blink_work(struct pca9633_led *pca9633)
> +{
> + u8 ledout = i2c_smbus_read_byte_data(pca9633->client, PCA9633_LEDOUT);
> + u8 mode2 = i2c_smbus_read_byte_data(pca9633->client, PCA9633_MODE2);
> + int shift = 2 * pca9633->led_num;
> + u8 mask = 0x3 << shift;
> +
> + i2c_smbus_write_byte_data(pca9633->client, PCA9633_GRPPWM,
> + pca9633->gdc);
> +
> + i2c_smbus_write_byte_data(pca9633->client, PCA9633_GRPFREQ,
> + pca9633->gfrq);
> +
> + if (!(mode2 & PCA9633_MODE2_DMBLNK))
> + i2c_smbus_write_byte_data(pca9633->client, PCA9633_MODE2,
> + mode2 | PCA9633_MODE2_DMBLNK);
> +
> + if ((ledout & mask) != (PCA9633_LED_GRP_PWM << shift))
> + i2c_smbus_write_byte_data(pca9633->client, PCA9633_LEDOUT,
> + (ledout & ~mask) | (PCA9633_LED_GRP_PWM << shift));
> +}
> +
> +static void pca9633_work(struct work_struct *work)
> +{
> + struct pca9633_led *pca9633 = container_of(work,
> + struct pca9633_led, work);
> +
> + switch (pca9633->cmd) {
> + case BRIGHTNESS_SET:
> + pca9633_brightness_work(pca9633);
> + break;
> + case BLINK_SET:
> + pca9633_blink_work(pca9633);
> + break;
> + };
> +}
> +
> static void pca9633_led_set(struct led_classdev *led_cdev,
> enum led_brightness value)
> {
> @@ -85,6 +145,7 @@ static void pca9633_led_set(struct led_classdev *led_cdev,
>
> pca9633 = container_of(led_cdev, struct pca9633_led, led_cdev);
>
> + pca9633->cmd = BRIGHTNESS_SET;
> pca9633->brightness = value;
>
> /*
> @@ -94,6 +155,64 @@ static void pca9633_led_set(struct led_classdev *led_cdev,
> schedule_work(&pca9633->work);
> }
>
> +static int pca9633_blink_set(struct led_classdev *led_cdev,
> + unsigned long *delay_on, unsigned long *delay_off)
> +{
> + struct pca9633_led *pca9633;
> + unsigned long time_on, time_off, period;
> + u8 gdc, gfrq;
> +
> + pca9633 = container_of(led_cdev, struct pca9633_led, led_cdev);
> +
> + time_on = *delay_on;
> + time_off = *delay_off;
> +
> + /* If both zero, pick reasonable defaults of 500ms each */
> + if (!time_on && !time_off) {
> + time_on = 500;
> + time_off = 500;
> + }
> +
> + period = time_on + time_off;
> +
> + /* If period not supported by hardware, default to someting sane. */
> + if ((period < PCA9632_BLINK_PERIOD_MIN) ||
> + (period > PCA9632_BLINK_PERIOD_MAX)) {
> + time_on = 500;
> + time_off = 500;
> + period = time_on + time_off;
> + }
> +
> + /*
> + * From manual: duty cycle = (GDC / 256) ->
> + * (time_on / period) = (GDC / 256) ->
> + * GDC = ((time_on * 256) / period)
> + */
> + gdc = (time_on * 256) / period;
> +
> + /*
> + * From manual: period = ((GFRQ + 1) / 24) in seconds.
> + * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
> + * GFRQ = ((period * 24 / 1000) - 1)
> + */
> + gfrq = (period * 24 / 1000) - 1;
> +
> + pca9633->cmd = BLINK_SET;
> + pca9633->gdc = gdc;
> + pca9633->gfrq = gfrq;
> +
> + /*
> + * Must use workqueue for the actual I/O since I2C operations
> + * can sleep.
> + */
> + schedule_work(&pca9633->work);
> +
> + *delay_on = time_on;
> + *delay_off = time_off;
> +
> + return 0;
> +}
> +
> #if IS_ENABLED(CONFIG_OF)
> static struct pca9633_platform_data *
> pca9633_dt_init(struct i2c_client *client)
> @@ -140,6 +259,12 @@ pca9633_dt_init(struct i2c_client *client)
> else
> pdata->outdrv = PCA9633_OPEN_DRAIN;
>
> + /* default to software blinking unless hardware blinking is specified */
> + if (of_property_read_bool(np, "nxp,hw-blink"))
> + pdata->blink_type = PCA9633_HW_BLINK;
> + else
> + pdata->blink_type = PCA9633_SW_BLINK;
> +
> return pdata;
> }
>
> @@ -206,7 +331,10 @@ static int pca9633_probe(struct i2c_client *client,
> pca9633[i].led_cdev.name = pca9633[i].name;
> pca9633[i].led_cdev.brightness_set = pca9633_led_set;
>
> - INIT_WORK(&pca9633[i].work, pca9633_led_work);
> + if (pdata && pdata->blink_type == PCA9633_HW_BLINK)
> + pca9633[i].led_cdev.blink_set = pca9633_blink_set;
> +
> + INIT_WORK(&pca9633[i].work, pca9633_work);
>
> err = led_classdev_register(&client->dev, &pca9633[i].led_cdev);
> if (err < 0)
> diff --git a/include/linux/platform_data/leds-pca9633.h b/include/linux/platform_data/leds-pca9633.h
> index c5bf29b..3c1037a 100644
> --- a/include/linux/platform_data/leds-pca9633.h
> +++ b/include/linux/platform_data/leds-pca9633.h
> @@ -27,9 +27,15 @@ enum pca9633_outdrv {
> PCA9633_TOTEM_POLE, /* aka push-pull */
> };
>
> +enum pca9633_blink_type {
> + PCA9633_SW_BLINK,
> + PCA9633_HW_BLINK,
> +};
> +
> struct pca9633_platform_data {
> struct led_platform_data leds;
> enum pca9633_outdrv outdrv;
> + enum pca9633_blink_type blink_type;
> };
>
> #endif /* __LINUX_PCA9633_H*/
> --
> 1.7.12
>
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