leds: Added driver for the NXP PCA9685 I2C chip
The NXP PCA9685 supports 16 channels/leds using a 12-bit PWM (4095
levels of brightness)
This driver supports configuration using platform_data.
Signed-off-by: Maximilian Güntner <maximilian.guentner@gmail.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
diff --git a/drivers/leds/leds-pca9685.c b/drivers/leds/leds-pca9685.c
new file mode 100644
index 0000000..6e1ef3a
--- /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");
