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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>
This commit is contained in:
Maximilian Güntner 2013-10-16 18:09:17 -07:00 committed by Bryan Wu
parent 1e08f72dd2
commit bb6febdc90
4 changed files with 259 additions and 0 deletions
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10
drivers/leds/Kconfig
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@ -300,6 +300,16 @@ config LEDS_PCA963X
LED driver chip accessed via the I2C bus. Supported
devices include PCA9633 and PCA9634
config LEDS_PCA9685
tristate "LED support for PCA9685 I2C chip"
depends on LEDS_CLASS
depends on I2C
help
This option enables support for LEDs connected to the PCA9685
LED driver chip accessed via the I2C bus.
The PCA9685 offers 12-bit PWM (4095 levels of brightness) on
16 individual channels.
config LEDS_WM831X_STATUS
tristate "LED support for status LEDs on WM831x PMICs"
depends on LEDS_CLASS

1
drivers/leds/Makefile
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@ -36,6 +36,7 @@ obj-$(CONFIG_LEDS_OT200) += leds-ot200.o
obj-$(CONFIG_LEDS_FSG) += leds-fsg.o
obj-$(CONFIG_LEDS_PCA955X) += leds-pca955x.o
obj-$(CONFIG_LEDS_PCA963X) += leds-pca963x.o
obj-$(CONFIG_LEDS_PCA9685) += leds-pca9685.o
obj-$(CONFIG_LEDS_DA903X) += leds-da903x.o
obj-$(CONFIG_LEDS_DA9052) += leds-da9052.o
obj-$(CONFIG_LEDS_WM831X_STATUS) += leds-wm831x-status.o

213
drivers/leds/leds-pca9685.c Normal file
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@ -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");

35
include/linux/platform_data/leds-pca9685.h Normal file
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@ -0,0 +1,35 @@
/*
* 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.h by Peter Meerwald <p.meerwald@bct-electronic.com>
*
* LED driver for the NXP PCA9685 PWM chip
*
*/
#ifndef __LINUX_PCA9685_H
#define __LINUX_PCA9685_H
#include <linux/leds.h>
enum pca9685_outdrv {
PCA9685_OPEN_DRAIN,
PCA9685_TOTEM_POLE,
};
enum pca9685_inverted {
PCA9685_NOT_INVERTED,
PCA9685_INVERTED,
};
struct pca9685_platform_data {
struct led_platform_data leds;
enum pca9685_outdrv outdrv;
enum pca9685_inverted inverted;
};
#endif /* __LINUX_PCA9685_H */