On Mon, Jul 15, 2013 at 4:18 PM, Mark A. Greer <mgreer@xxxxxxxxxxxxxxx> wrote:
> From: "Mark A. Greer" <mgreer@xxxxxxxxxxxxxxx>
>
> Add hardware blink support to the pca9633 driver.
>
> NOTE: This patch violates the leds infrastructure
> 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.
>
Sorry for the delay, I'm basically OK for this RFC. And could you
please put some NOTE in the code as a comment as well as the patch
description.
After that, I will put this patch on my devel branch.
Thanks,
-Bryan
> Signed-off-by: Mark A. Greer <mgreer@xxxxxxxxxxxxxxx>
> ---
>
> Based on linux-leds@xxxxxxxxxxxxxxx devel.
>
> Sending this as an RFC because of the issue described
> in the "NOTE:" section above.
>
> I doubt this is acceptable because of the issue but if
> there is something I can do to make it acceptable, I'd
> be happy to make the necessary changes.
>
> drivers/leds/leds-pca9633.c | 115 ++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 111 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/leds/leds-pca9633.c b/drivers/leds/leds-pca9633.c
> index 90935e4..6cc5568 100644
> --- a/drivers/leds/leds-pca9633.c
> +++ b/drivers/leds/leds-pca9633.c
> @@ -31,30 +31,44 @@
> #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 +92,43 @@ 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 +136,7 @@ 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 +146,60 @@ 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 < PCA9632_BLINK_PERIOD_MIN) ||
> + (period > PCA9632_BLINK_PERIOD_MAX))
> + return -EINVAL;
> +
> + /*
> + * 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)
> @@ -205,8 +311,9 @@ 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;
> + pca9633[i].led_cdev.blink_set = pca9633_blink_set;
>
> - INIT_WORK(&pca9633[i].work, pca9633_led_work);
> + INIT_WORK(&pca9633[i].work, pca9633_work);
>
> err = led_classdev_register(&client->dev, &pca9633[i].led_cdev);
> if (err < 0)
> --
> 1.7.12
>
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