drivers/leds/leds-pca9633.c

   1 /*
   2  * Copyright 2011 bct electronic GmbH
   3  *
   4  * Author: Peter Meerwald <p.meerwald@bct-electronic.com>
   5  *
   6  * Based on leds-pca955x.c
   7  *
   8  * This file is subject to the terms and conditions of version 2 of
   9  * the GNU General Public License.  See the file COPYING in the main
  10  * directory of this archive for more details.
  11  *
  12  * LED driver for the PCA9633 I2C LED driver (7-bit slave address 0x62)
  13  *
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/delay.h>
  18 #include <linux/string.h>
  19 #include <linux/ctype.h>
  20 #include <linux/leds.h>
  21 #include <linux/err.h>
  22 #include <linux/i2c.h>
  23 #include <linux/workqueue.h>
  24 #include <linux/slab.h>
  25 #include <linux/platform_data/leds-pca9633.h>
  26
  27 /* LED select registers determine the source that drives LED outputs */
  28 #define PCA9633_LED_OFF         0x0     /* LED driver off */
  29 #define PCA9633_LED_ON          0x1     /* LED driver on */
  30 #define PCA9633_LED_PWM         0x2     /* Controlled through PWM */
  31 #define PCA9633_LED_GRP_PWM     0x3     /* Controlled through PWM/GRPPWM */
  32
  33 #define PCA9633_MODE1           0x00
  34 #define PCA9633_MODE2           0x01
  35 #define PCA9633_PWM_BASE        0x02
  36 #define PCA9633_LEDOUT          0x08
  37
  38 static const struct i2c_device_id pca9633_id[] = {
  39         { "pca9633", 0 },
  40         { }
  41 };
  42 MODULE_DEVICE_TABLE(i2c, pca9633_id);
  43
  44 struct pca9633_led {
  45         struct i2c_client *client;
  46         struct work_struct work;
  47         enum led_brightness brightness;
  48         struct led_classdev led_cdev;
  49         int led_num; /* 0 .. 3 potentially */
  50         char name[32];
  51 };
  52
  53 static void pca9633_led_work(struct work_struct *work)
  54 {
  55         struct pca9633_led *pca9633 = container_of(work,
  56                 struct pca9633_led, work);
  57         u8 ledout = i2c_smbus_read_byte_data(pca9633->client, PCA9633_LEDOUT);
  58         int shift = 2 * pca9633->led_num;
  59         u8 mask = 0x3 << shift;
  60
  61         switch (pca9633->brightness) {
  62         case LED_FULL:
  63                 i2c_smbus_write_byte_data(pca9633->client, PCA9633_LEDOUT,
  64                         (ledout & ~mask) | (PCA9633_LED_ON << shift));
  65                 break;
  66         case LED_OFF:
  67                 i2c_smbus_write_byte_data(pca9633->client, PCA9633_LEDOUT,
  68                         ledout & ~mask);
  69                 break;
  70         default:
  71                 i2c_smbus_write_byte_data(pca9633->client,
  72                         PCA9633_PWM_BASE + pca9633->led_num,
  73                         pca9633->brightness);
  74                 i2c_smbus_write_byte_data(pca9633->client, PCA9633_LEDOUT,
  75                         (ledout & ~mask) | (PCA9633_LED_PWM << shift));
  76                 break;
  77         }
  78 }
  79
  80 static void pca9633_led_set(struct led_classdev *led_cdev,
  81         enum led_brightness value)
  82 {
  83         struct pca9633_led *pca9633;
  84
  85         pca9633 = container_of(led_cdev, struct pca9633_led, led_cdev);
  86
  87         pca9633->brightness = value;
  88
  89         /*
  90          * Must use workqueue for the actual I/O since I2C operations
  91          * can sleep.
  92          */
  93         schedule_work(&pca9633->work);
  94 }
  95
  96 static int pca9633_probe(struct i2c_client *client,
  97                                         const struct i2c_device_id *id)
  98 {
  99         struct pca9633_led *pca9633;
 100         struct pca9633_platform_data *pdata;
 101         int i, err;
 102
 103         pdata = client->dev.platform_data;
 104
 105         if (pdata) {
 106                 if (pdata->leds.num_leds <= 0 || pdata->leds.num_leds > 4) {
 107                         dev_err(&client->dev, "board info must claim at most 4 LEDs");
 108                         return -EINVAL;
 109                 }
 110         }
 111
 112         pca9633 = devm_kzalloc(&client->dev, 4 * sizeof(*pca9633), GFP_KERNEL);
 113         if (!pca9633)
 114                 return -ENOMEM;
 115
 116         i2c_set_clientdata(client, pca9633);
 117
 118         for (i = 0; i < 4; i++) {
 119                 pca9633[i].client = client;
 120                 pca9633[i].led_num = i;
 121
 122                 /* Platform data can specify LED names and default triggers */
 123                 if (pdata && i < pdata->leds.num_leds) {
 124                         if (pdata->leds.leds[i].name)
 125                                 snprintf(pca9633[i].name,
 126                                          sizeof(pca9633[i].name), "pca9633:%s",
 127                                          pdata->leds.leds[i].name);
 128                         if (pdata->leds.leds[i].default_trigger)
 129                                 pca9633[i].led_cdev.default_trigger =
 130                                         pdata->leds.leds[i].default_trigger;
 131                 } else {
 132                         snprintf(pca9633[i].name, sizeof(pca9633[i].name),
 133                                  "pca9633:%d", i);
 134                 }
 135
 136                 pca9633[i].led_cdev.name = pca9633[i].name;
 137                 pca9633[i].led_cdev.brightness_set = pca9633_led_set;
 138
 139                 INIT_WORK(&pca9633[i].work, pca9633_led_work);
 140
 141                 err = led_classdev_register(&client->dev, &pca9633[i].led_cdev);
 142                 if (err < 0)
 143                         goto exit;
 144         }
 145
 146         /* Disable LED all-call address and set normal mode */
 147         i2c_smbus_write_byte_data(client, PCA9633_MODE1, 0x00);
 148
 149         /* Configure output: open-drain or totem pole (push-pull) */
 150         if (pdata && pdata->outdrv == PCA9633_OPEN_DRAIN)
 151                 i2c_smbus_write_byte_data(client, PCA9633_MODE2, 0x01);
 152
 153         /* Turn off LEDs */
 154         i2c_smbus_write_byte_data(client, PCA9633_LEDOUT, 0x00);
 155
 156         return 0;
 157
 158 exit:
 159         while (i--) {
 160                 led_classdev_unregister(&pca9633[i].led_cdev);
 161                 cancel_work_sync(&pca9633[i].work);
 162         }
 163
 164         return err;
 165 }
 166
 167 static int pca9633_remove(struct i2c_client *client)
 168 {
 169         struct pca9633_led *pca9633 = i2c_get_clientdata(client);
 170         int i;
 171
 172         for (i = 0; i < 4; i++) {
 173                 led_classdev_unregister(&pca9633[i].led_cdev);
 174                 cancel_work_sync(&pca9633[i].work);
 175         }
 176
 177         return 0;
 178 }
 179
 180 static struct i2c_driver pca9633_driver = {
 181         .driver = {
 182                 .name   = "leds-pca9633",
 183                 .owner  = THIS_MODULE,
 184         },
 185         .probe  = pca9633_probe,
 186         .remove = pca9633_remove,
 187         .id_table = pca9633_id,
 188 };
 189
 190 module_i2c_driver(pca9633_driver);
 191
 192 MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
 193 MODULE_DESCRIPTION("PCA9633 LED driver");
 194 MODULE_LICENSE("GPL v2");