diff options
Diffstat (limited to 'drivers/leds')
| -rw-r--r-- | drivers/leds/leds-pca9633.c | 136 |
1 files changed, 132 insertions, 4 deletions
diff --git a/drivers/leds/leds-pca9633.c b/drivers/leds/leds-pca9633.c index 90935e465c4d..77b3f24b7207 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) |