diff options
Diffstat (limited to 'drivers/leds/leds-pca9633.c')
| -rw-r--r-- | drivers/leds/leds-pca9633.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/drivers/leds/leds-pca9633.c b/drivers/leds/leds-pca9633.c new file mode 100644 index 000000000000..80cb61adc2d6 --- /dev/null +++ b/drivers/leds/leds-pca9633.c @@ -0,0 +1,195 @@ +/* + * Copyright 2011 bct electronic GmbH + * + * Author: Peter Meerwald <p.meerwald@bct-electronic.com> + * + * Based on leds-pca955x.c + * + * This file is subject to the terms and conditions of version 2 of + * the GNU General Public License. See the file COPYING in the main + * directory of this archive for more details. + * + * LED driver for the PCA9633 I2C LED driver (7-bit slave address 0x62) + * + */ + +#include <linux/module.h> +#include <linux/delay.h> +#include <linux/string.h> +#include <linux/ctype.h> +#include <linux/leds.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/workqueue.h> +#include <linux/slab.h> + +/* LED select registers determine the source that drives LED outputs */ +#define PCA9633_LED_OFF 0x0 /* LED driver off */ +#define PCA9633_LED_ON 0x1 /* LED driver on */ +#define PCA9633_LED_PWM 0x2 /* Controlled through PWM */ +#define PCA9633_LED_GRP_PWM 0x3 /* Controlled through PWM/GRPPWM */ + +#define PCA9633_MODE1 0x00 +#define PCA9633_MODE2 0x01 +#define PCA9633_PWM_BASE 0x02 +#define PCA9633_LEDOUT 0x08 + +static const struct i2c_device_id pca9633_id[] = { + { "pca9633", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, pca9633_id); + +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 */ + char name[32]; +}; + +static void pca9633_led_work(struct work_struct *work) +{ + 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; + + switch (pca9633->brightness) { + case LED_FULL: + i2c_smbus_write_byte_data(pca9633->client, PCA9633_LEDOUT, + (ledout & ~mask) | (PCA9633_LED_ON << shift)); + break; + case LED_OFF: + i2c_smbus_write_byte_data(pca9633->client, PCA9633_LEDOUT, + ledout & ~mask); + break; + default: + i2c_smbus_write_byte_data(pca9633->client, + PCA9633_PWM_BASE + pca9633->led_num, + pca9633->brightness); + i2c_smbus_write_byte_data(pca9633->client, PCA9633_LEDOUT, + (ledout & ~mask) | (PCA9633_LED_PWM << shift)); + break; + } +} + +static void pca9633_led_set(struct led_classdev *led_cdev, + enum led_brightness value) +{ + struct pca9633_led *pca9633; + + pca9633 = container_of(led_cdev, struct pca9633_led, led_cdev); + + pca9633->brightness = value; + + /* + * Must use workqueue for the actual I/O since I2C operations + * can sleep. + */ + schedule_work(&pca9633->work); +} + +static int __devinit pca9633_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct pca9633_led *pca9633; + struct i2c_adapter *adapter; + struct led_platform_data *pdata; + int i, err; + + adapter = to_i2c_adapter(client->dev.parent); + pdata = client->dev.platform_data; + + if (pdata) { + if (pdata->num_leds <= 0 || pdata->num_leds > 4) { + dev_err(&client->dev, "board info must claim at most 4 LEDs"); + return -EINVAL; + } + } + + pca9633 = kcalloc(4, sizeof(*pca9633), GFP_KERNEL); + if (!pca9633) + return -ENOMEM; + + i2c_set_clientdata(client, pca9633); + + for (i = 0; i < 4; i++) { + pca9633[i].client = client; + pca9633[i].led_num = i; + + /* Platform data can specify LED names and default triggers */ + if (pdata && i < pdata->num_leds) { + if (pdata->leds[i].name) + snprintf(pca9633[i].name, + sizeof(pca9633[i].name), "pca9633:%s", + pdata->leds[i].name); + if (pdata->leds[i].default_trigger) + pca9633[i].led_cdev.default_trigger = + pdata->leds[i].default_trigger; + } else { + snprintf(pca9633[i].name, sizeof(pca9633[i].name), + "pca9633:%d", i); + } + + 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); + + err = led_classdev_register(&client->dev, &pca9633[i].led_cdev); + if (err < 0) + goto exit; + } + + /* Disable LED all-call address and set normal mode */ + i2c_smbus_write_byte_data(client, PCA9633_MODE1, 0x00); + + /* Turn off LEDs */ + i2c_smbus_write_byte_data(client, PCA9633_LEDOUT, 0x00); + + return 0; + +exit: + while (i--) { + led_classdev_unregister(&pca9633[i].led_cdev); + cancel_work_sync(&pca9633[i].work); + } + + kfree(pca9633); + + return err; +} + +static int __devexit pca9633_remove(struct i2c_client *client) +{ + struct pca9633_led *pca9633 = i2c_get_clientdata(client); + int i; + + for (i = 0; i < 4; i++) { + led_classdev_unregister(&pca9633[i].led_cdev); + cancel_work_sync(&pca9633[i].work); + } + + kfree(pca9633); + + return 0; +} + +static struct i2c_driver pca9633_driver = { + .driver = { + .name = "leds-pca9633", + .owner = THIS_MODULE, + }, + .probe = pca9633_probe, + .remove = __devexit_p(pca9633_remove), + .id_table = pca9633_id, +}; + +module_i2c_driver(pca9633_driver); + +MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>"); +MODULE_DESCRIPTION("PCA9633 LED driver"); +MODULE_LICENSE("GPL v2"); |