/*
* 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 led_platform_data *pdata;
int i, err;
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 = devm_kzalloc(&client->dev, 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);
}
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);
}
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");
