diff options
Diffstat (limited to 'drivers/leds/leds-pca9685.c')
| -rw-r--r-- | drivers/leds/leds-pca9685.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/drivers/leds/leds-pca9685.c b/drivers/leds/leds-pca9685.c new file mode 100644 index 00000000000..6e1ef3a9d6e --- /dev/null +++ b/drivers/leds/leds-pca9685.c @@ -0,0 +1,213 @@ +/* + * Copyright 2013 Maximilian Güntner <maximilian.guentner@gmail.com> + * + * 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. + * + * Based on leds-pca963x.c driver by + * Peter Meerwald <p.meerwald@bct-electronic.com> + * + * Driver for the NXP PCA9685 12-Bit PWM LED driver chip. + * + */ + +#include <linux/ctype.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/leds.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/workqueue.h> + +#include <linux/platform_data/leds-pca9685.h> + +/* Register Addresses */ +#define PCA9685_MODE1 0x00 +#define PCA9685_MODE2 0x01 +#define PCA9685_LED0_ON_L 0x06 +#define PCA9685_ALL_LED_ON_L 0xFA + +/* MODE1 Register */ +#define PCA9685_ALLCALL 0x00 +#define PCA9685_SLEEP 0x04 +#define PCA9685_AI 0x05 + +/* MODE2 Register */ +#define PCA9685_INVRT 0x04 +#define PCA9685_OUTDRV 0x02 + +static const struct i2c_device_id pca9685_id[] = { + { "pca9685", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, pca9685_id); + +struct pca9685_led { + struct i2c_client *client; + struct work_struct work; + u16 brightness; + struct led_classdev led_cdev; + int led_num; /* 0-15 */ + char name[32]; +}; + +static void pca9685_write_msg(struct i2c_client *client, u8 *buf, u8 len) +{ + struct i2c_msg msg = { + .addr = client->addr, + .flags = 0x00, + .len = len, + .buf = buf + }; + i2c_transfer(client->adapter, &msg, 1); +} + +static void pca9685_all_off(struct i2c_client *client) +{ + u8 i2c_buffer[5] = {PCA9685_ALL_LED_ON_L, 0x00, 0x00, 0x00, 0x10}; + pca9685_write_msg(client, i2c_buffer, 5); +} + +static void pca9685_led_work(struct work_struct *work) +{ + struct pca9685_led *pca9685; + u8 i2c_buffer[5]; + + pca9685 = container_of(work, struct pca9685_led, work); + i2c_buffer[0] = PCA9685_LED0_ON_L + 4 * pca9685->led_num; + /* + * 4095 is the maximum brightness, so we set the ON time to 0x1000 + * which disables the PWM generator for that LED + */ + if (pca9685->brightness == 4095) + *((__le16 *)(i2c_buffer+1)) = cpu_to_le16(0x1000); + else + *((__le16 *)(i2c_buffer+1)) = 0x0000; + + if (pca9685->brightness == 0) + *((__le16 *)(i2c_buffer+3)) = cpu_to_le16(0x1000); + else if (pca9685->brightness == 4095) + *((__le16 *)(i2c_buffer+3)) = 0x0000; + else + *((__le16 *)(i2c_buffer+3)) = cpu_to_le16(pca9685->brightness); + + pca9685_write_msg(pca9685->client, i2c_buffer, 5); +} + +static void pca9685_led_set(struct led_classdev *led_cdev, + enum led_brightness value) +{ + struct pca9685_led *pca9685; + pca9685 = container_of(led_cdev, struct pca9685_led, led_cdev); + pca9685->brightness = value; + + schedule_work(&pca9685->work); +} + +static int pca9685_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct pca9685_led *pca9685; + struct pca9685_platform_data *pdata; + int err; + u8 i; + + pdata = dev_get_platdata(&client->dev); + if (pdata) { + if (pdata->leds.num_leds < 1 || pdata->leds.num_leds > 15) { + dev_err(&client->dev, "board info must claim 1-16 LEDs"); + return -EINVAL; + } + } + + pca9685 = devm_kzalloc(&client->dev, 16 * sizeof(*pca9685), GFP_KERNEL); + if (!pca9685) + return -ENOMEM; + + i2c_set_clientdata(client, pca9685); + pca9685_all_off(client); + + for (i = 0; i < 16; i++) { + pca9685[i].client = client; + pca9685[i].led_num = i; + pca9685[i].name[0] = '\0'; + if (pdata && i < pdata->leds.num_leds) { + if (pdata->leds.leds[i].name) + strncpy(pca9685[i].name, + pdata->leds.leds[i].name, + sizeof(pca9685[i].name)-1); + if (pdata->leds.leds[i].default_trigger) + pca9685[i].led_cdev.default_trigger = + pdata->leds.leds[i].default_trigger; + } + if (strlen(pca9685[i].name) == 0) { + /* + * Write adapter and address to the name as well. + * Otherwise multiple chips attached to one host would + * not work. + */ + snprintf(pca9685[i].name, sizeof(pca9685[i].name), + "pca9685:%d:x%.2x:%d", + client->adapter->nr, client->addr, i); + } + pca9685[i].led_cdev.name = pca9685[i].name; + pca9685[i].led_cdev.max_brightness = 0xfff; + pca9685[i].led_cdev.brightness_set = pca9685_led_set; + + INIT_WORK(&pca9685[i].work, pca9685_led_work); + err = led_classdev_register(&client->dev, &pca9685[i].led_cdev); + if (err < 0) + goto exit; + } + + if (pdata) + i2c_smbus_write_byte_data(client, PCA9685_MODE2, + pdata->outdrv << PCA9685_OUTDRV | + pdata->inverted << PCA9685_INVRT); + else + i2c_smbus_write_byte_data(client, PCA9685_MODE2, + PCA9685_TOTEM_POLE << PCA9685_OUTDRV); + /* Enable Auto-Increment, enable oscillator, ALLCALL/SUBADDR disabled */ + i2c_smbus_write_byte_data(client, PCA9685_MODE1, BIT(PCA9685_AI)); + + return 0; + +exit: + while (i--) { + led_classdev_unregister(&pca9685[i].led_cdev); + cancel_work_sync(&pca9685[i].work); + } + return err; +} + +static int pca9685_remove(struct i2c_client *client) +{ + struct pca9685_led *pca9685 = i2c_get_clientdata(client); + u8 i; + + for (i = 0; i < 16; i++) { + led_classdev_unregister(&pca9685[i].led_cdev); + cancel_work_sync(&pca9685[i].work); + } + pca9685_all_off(client); + return 0; +} + +static struct i2c_driver pca9685_driver = { + .driver = { + .name = "leds-pca9685", + .owner = THIS_MODULE, + }, + .probe = pca9685_probe, + .remove = pca9685_remove, + .id_table = pca9685_id, +}; + +module_i2c_driver(pca9685_driver); + +MODULE_AUTHOR("Maximilian Güntner <maximilian.guentner@gmail.com>"); +MODULE_DESCRIPTION("PCA9685 LED Driver"); +MODULE_LICENSE("GPL v2"); |