leds: add driver for LM3530 ALS
authorShreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com>
Tue, 22 Mar 2011 23:30:16 +0000 (16:30 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 23 Mar 2011 00:43:59 +0000 (17:43 -0700)
Simple backlight driver for National Semiconductor LM3530.  Presently only
manual mode is supported, PWM and ALS support to be added.

Signed-off-by: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/leds/Kconfig
drivers/leds/Makefile
drivers/leds/leds-lm3530.c [new file with mode: 0644]
include/linux/led-lm3530.h [new file with mode: 0644]

index 6f190f4cdbc00e4917c457dcd004060c3b8976ba..9bec8699b8a327e107ddeb4fcfadb01e588c54e7 100644 (file)
@@ -34,6 +34,16 @@ config LEDS_ATMEL_PWM
          This option enables support for LEDs driven using outputs
          of the dedicated PWM controller found on newer Atmel SOCs.
 
+config LEDS_LM3530
+       tristate "LCD Backlight driver for LM3530"
+       depends on LEDS_CLASS
+       depends on I2C
+       help
+         This option enables support for the LCD backlight using
+         LM3530 ambient light sensor chip. This ALS chip can be
+         controlled manually or using PWM input or using ambient
+         light automatically.
+
 config LEDS_LOCOMO
        tristate "LED Support for Locomo device"
        depends on LEDS_CLASS
index aae6989ff6b63445e6b6c974df537f0f0784fe3f..39c80fca84d276e3327ec4a69a902a85ebc6ae44 100644 (file)
@@ -9,6 +9,7 @@ obj-$(CONFIG_LEDS_88PM860X)             += leds-88pm860x.o
 obj-$(CONFIG_LEDS_ATMEL_PWM)           += leds-atmel-pwm.o
 obj-$(CONFIG_LEDS_BD2802)              += leds-bd2802.o
 obj-$(CONFIG_LEDS_LOCOMO)              += leds-locomo.o
+obj-$(CONFIG_LEDS_LM3530)              += leds-lm3530.o
 obj-$(CONFIG_LEDS_MIKROTIK_RB532)      += leds-rb532.o
 obj-$(CONFIG_LEDS_S3C24XX)             += leds-s3c24xx.o
 obj-$(CONFIG_LEDS_AMS_DELTA)           += leds-ams-delta.o
diff --git a/drivers/leds/leds-lm3530.c b/drivers/leds/leds-lm3530.c
new file mode 100644 (file)
index 0000000..e7089a1
--- /dev/null
@@ -0,0 +1,378 @@
+/*
+ * Copyright (C) 2011 ST-Ericsson SA.
+ * Copyright (C) 2009 Motorola, Inc.
+ *
+ * License Terms: GNU General Public License v2
+ *
+ * Simple driver for National Semiconductor LM3530 Backlight driver chip
+ *
+ * Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
+ * based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com>
+ */
+
+#include <linux/i2c.h>
+#include <linux/leds.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/input.h>
+#include <linux/led-lm3530.h>
+#include <linux/types.h>
+
+#define LM3530_LED_DEV "lcd-backlight"
+#define LM3530_NAME "lm3530-led"
+
+#define LM3530_GEN_CONFIG              0x10
+#define LM3530_ALS_CONFIG              0x20
+#define LM3530_BRT_RAMP_RATE           0x30
+#define LM3530_ALS_ZONE_REG            0x40
+#define LM3530_ALS_IMP_SELECT          0x41
+#define LM3530_BRT_CTRL_REG            0xA0
+#define LM3530_ALS_ZB0_REG             0x60
+#define LM3530_ALS_ZB1_REG             0x61
+#define LM3530_ALS_ZB2_REG             0x62
+#define LM3530_ALS_ZB3_REG             0x63
+#define LM3530_ALS_Z0T_REG             0x70
+#define LM3530_ALS_Z1T_REG             0x71
+#define LM3530_ALS_Z2T_REG             0x72
+#define LM3530_ALS_Z3T_REG             0x73
+#define LM3530_ALS_Z4T_REG             0x74
+#define LM3530_REG_MAX                 15
+
+/* General Control Register */
+#define LM3530_EN_I2C_SHIFT            (0)
+#define LM3530_RAMP_LAW_SHIFT          (1)
+#define LM3530_MAX_CURR_SHIFT          (2)
+#define LM3530_EN_PWM_SHIFT            (5)
+#define LM3530_PWM_POL_SHIFT           (6)
+#define LM3530_EN_PWM_SIMPLE_SHIFT     (7)
+
+#define LM3530_ENABLE_I2C              (1 << LM3530_EN_I2C_SHIFT)
+#define LM3530_ENABLE_PWM              (1 << LM3530_EN_PWM_SHIFT)
+#define LM3530_POL_LOW                 (1 << LM3530_PWM_POL_SHIFT)
+#define LM3530_ENABLE_PWM_SIMPLE       (1 << LM3530_EN_PWM_SIMPLE_SHIFT)
+
+/* ALS Config Register Options */
+#define LM3530_ALS_AVG_TIME_SHIFT      (0)
+#define LM3530_EN_ALS_SHIFT            (3)
+#define LM3530_ALS_SEL_SHIFT           (5)
+
+#define LM3530_ENABLE_ALS              (3 << LM3530_EN_ALS_SHIFT)
+
+/* Brightness Ramp Rate Register */
+#define LM3530_BRT_RAMP_FALL_SHIFT     (0)
+#define LM3530_BRT_RAMP_RISE_SHIFT     (3)
+
+/* ALS Resistor Select */
+#define LM3530_ALS1_IMP_SHIFT          (0)
+#define LM3530_ALS2_IMP_SHIFT          (4)
+
+/* Zone Boundary Register defaults */
+#define LM3530_DEF_ZB_0                        (0x33)
+#define LM3530_DEF_ZB_1                        (0x66)
+#define LM3530_DEF_ZB_2                        (0x99)
+#define LM3530_DEF_ZB_3                        (0xCC)
+
+/* Zone Target Register defaults */
+#define LM3530_DEF_ZT_0                        (0x19)
+#define LM3530_DEF_ZT_1                        (0x33)
+#define LM3530_DEF_ZT_2                        (0x4C)
+#define LM3530_DEF_ZT_3                        (0x66)
+#define LM3530_DEF_ZT_4                        (0x7F)
+
+struct lm3530_mode_map {
+       const char *mode;
+       enum lm3530_mode mode_val;
+};
+
+static struct lm3530_mode_map mode_map[] = {
+       { "man", LM3530_BL_MODE_MANUAL },
+       { "als", LM3530_BL_MODE_ALS },
+       { "pwm", LM3530_BL_MODE_PWM },
+};
+
+/**
+ * struct lm3530_data
+ * @led_dev: led class device
+ * @client: i2c client
+ * @pdata: LM3530 platform data
+ * @mode: mode of operation - manual, ALS, PWM
+ */
+struct lm3530_data {
+       struct led_classdev led_dev;
+       struct i2c_client *client;
+       struct lm3530_platform_data *pdata;
+       enum lm3530_mode mode;
+};
+
+static const u8 lm3530_reg[LM3530_REG_MAX] = {
+       LM3530_GEN_CONFIG,
+       LM3530_ALS_CONFIG,
+       LM3530_BRT_RAMP_RATE,
+       LM3530_ALS_ZONE_REG,
+       LM3530_ALS_IMP_SELECT,
+       LM3530_BRT_CTRL_REG,
+       LM3530_ALS_ZB0_REG,
+       LM3530_ALS_ZB1_REG,
+       LM3530_ALS_ZB2_REG,
+       LM3530_ALS_ZB3_REG,
+       LM3530_ALS_Z0T_REG,
+       LM3530_ALS_Z1T_REG,
+       LM3530_ALS_Z2T_REG,
+       LM3530_ALS_Z3T_REG,
+       LM3530_ALS_Z4T_REG,
+};
+
+static int lm3530_get_mode_from_str(const char *str)
+{
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(mode_map); i++)
+               if (sysfs_streq(str, mode_map[i].mode))
+                       return mode_map[i].mode_val;
+
+       return -1;
+}
+
+static int lm3530_init_registers(struct lm3530_data *drvdata)
+{
+       int ret = 0;
+       int i;
+       u8 gen_config;
+       u8 als_config = 0;
+       u8 brt_ramp;
+       u8 als_imp_sel = 0;
+       u8 brightness;
+       u8 reg_val[LM3530_REG_MAX];
+       struct lm3530_platform_data *pltfm = drvdata->pdata;
+       struct i2c_client *client = drvdata->client;
+
+       gen_config = (pltfm->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
+                       ((pltfm->max_current & 7) << LM3530_MAX_CURR_SHIFT);
+
+       if (drvdata->mode == LM3530_BL_MODE_MANUAL ||
+           drvdata->mode == LM3530_BL_MODE_ALS)
+               gen_config |= (LM3530_ENABLE_I2C);
+
+       if (drvdata->mode == LM3530_BL_MODE_ALS) {
+               als_config =
+                       (pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
+                       (LM3530_ENABLE_ALS) |
+                       (pltfm->als_input_mode << LM3530_ALS_SEL_SHIFT);
+
+               als_imp_sel =
+                       (pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
+                       (pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
+       }
+
+       if (drvdata->mode == LM3530_BL_MODE_PWM)
+               gen_config |= (LM3530_ENABLE_PWM) |
+                               (pltfm->pwm_pol_hi << LM3530_PWM_POL_SHIFT) |
+                               (LM3530_ENABLE_PWM_SIMPLE);
+
+       brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
+                       (pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);
+
+       brightness = pltfm->brt_val;
+
+       reg_val[0] = gen_config;        /* LM3530_GEN_CONFIG */
+       reg_val[1] = als_config;        /* LM3530_ALS_CONFIG */
+       reg_val[2] = brt_ramp;          /* LM3530_BRT_RAMP_RATE */
+       reg_val[3] = 0x00;              /* LM3530_ALS_ZONE_REG */
+       reg_val[4] = als_imp_sel;       /* LM3530_ALS_IMP_SELECT */
+       reg_val[5] = brightness;        /* LM3530_BRT_CTRL_REG */
+       reg_val[6] = LM3530_DEF_ZB_0;   /* LM3530_ALS_ZB0_REG */
+       reg_val[7] = LM3530_DEF_ZB_1;   /* LM3530_ALS_ZB1_REG */
+       reg_val[8] = LM3530_DEF_ZB_2;   /* LM3530_ALS_ZB2_REG */
+       reg_val[9] = LM3530_DEF_ZB_3;   /* LM3530_ALS_ZB3_REG */
+       reg_val[10] = LM3530_DEF_ZT_0;  /* LM3530_ALS_Z0T_REG */
+       reg_val[11] = LM3530_DEF_ZT_1;  /* LM3530_ALS_Z1T_REG */
+       reg_val[12] = LM3530_DEF_ZT_2;  /* LM3530_ALS_Z2T_REG */
+       reg_val[13] = LM3530_DEF_ZT_3;  /* LM3530_ALS_Z3T_REG */
+       reg_val[14] = LM3530_DEF_ZT_4;  /* LM3530_ALS_Z4T_REG */
+
+       for (i = 0; i < LM3530_REG_MAX; i++) {
+               ret = i2c_smbus_write_byte_data(client,
+                               lm3530_reg[i], reg_val[i]);
+               if (ret)
+                       break;
+       }
+
+       return ret;
+}
+
+static void lm3530_brightness_set(struct led_classdev *led_cdev,
+                                    enum led_brightness brt_val)
+{
+       int err;
+       struct lm3530_data *drvdata =
+           container_of(led_cdev, struct lm3530_data, led_dev);
+
+       switch (drvdata->mode) {
+       case LM3530_BL_MODE_MANUAL:
+
+               /* set the brightness in brightness control register*/
+               err = i2c_smbus_write_byte_data(drvdata->client,
+                               LM3530_BRT_CTRL_REG, brt_val / 2);
+               if (err)
+                       dev_err(&drvdata->client->dev,
+                               "Unable to set brightness: %d\n", err);
+               break;
+       case LM3530_BL_MODE_ALS:
+               break;
+       case LM3530_BL_MODE_PWM:
+               break;
+       default:
+               break;
+       }
+}
+
+
+static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
+                                  *attr, const char *buf, size_t size)
+{
+       int err;
+       struct i2c_client *client = container_of(
+                                       dev->parent, struct i2c_client, dev);
+       struct lm3530_data *drvdata = i2c_get_clientdata(client);
+       int mode;
+
+       mode = lm3530_get_mode_from_str(buf);
+       if (mode < 0) {
+               dev_err(dev, "Invalid mode\n");
+               return -EINVAL;
+       }
+
+       if (mode == LM3530_BL_MODE_MANUAL)
+               drvdata->mode = LM3530_BL_MODE_MANUAL;
+       else if (mode == LM3530_BL_MODE_ALS)
+               drvdata->mode = LM3530_BL_MODE_ALS;
+       else if (mode == LM3530_BL_MODE_PWM) {
+               dev_err(dev, "PWM mode not supported\n");
+               return -EINVAL;
+       }
+
+       err = lm3530_init_registers(drvdata);
+       if (err) {
+               dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);
+               return err;
+       }
+
+       return sizeof(drvdata->mode);
+}
+
+static DEVICE_ATTR(mode, 0644, NULL, lm3530_mode_set);
+
+static int __devinit lm3530_probe(struct i2c_client *client,
+                          const struct i2c_device_id *id)
+{
+       struct lm3530_platform_data *pdata = client->dev.platform_data;
+       struct lm3530_data *drvdata;
+       int err = 0;
+
+       if (pdata == NULL) {
+               dev_err(&client->dev, "platform data required\n");
+               err = -ENODEV;
+               goto err_out;
+       }
+
+       /* BL mode */
+       if (pdata->mode > LM3530_BL_MODE_PWM) {
+               dev_err(&client->dev, "Illegal Mode request\n");
+               err = -EINVAL;
+               goto err_out;
+       }
+
+       if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+               dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
+               err = -EIO;
+               goto err_out;
+       }
+
+       drvdata = kzalloc(sizeof(struct lm3530_data), GFP_KERNEL);
+       if (drvdata == NULL) {
+               err = -ENOMEM;
+               goto err_out;
+       }
+
+       drvdata->mode = pdata->mode;
+       drvdata->client = client;
+       drvdata->pdata = pdata;
+       drvdata->led_dev.name = LM3530_LED_DEV;
+       drvdata->led_dev.brightness_set = lm3530_brightness_set;
+
+       i2c_set_clientdata(client, drvdata);
+
+       err = lm3530_init_registers(drvdata);
+       if (err < 0) {
+               dev_err(&client->dev, "Register Init failed: %d\n", err);
+               err = -ENODEV;
+               goto err_reg_init;
+       }
+
+       err = led_classdev_register((struct device *)
+                                     &client->dev, &drvdata->led_dev);
+       if (err < 0) {
+               dev_err(&client->dev, "Register led class failed: %d\n", err);
+               err = -ENODEV;
+               goto err_class_register;
+       }
+
+       err = device_create_file(drvdata->led_dev.dev, &dev_attr_mode);
+       if (err < 0) {
+               dev_err(&client->dev, "File device creation failed: %d\n", err);
+               err = -ENODEV;
+               goto err_create_file;
+       }
+
+       return 0;
+
+err_create_file:
+       led_classdev_unregister(&drvdata->led_dev);
+err_class_register:
+err_reg_init:
+       kfree(drvdata);
+err_out:
+       return err;
+}
+
+static int __devexit lm3530_remove(struct i2c_client *client)
+{
+       struct lm3530_data *drvdata = i2c_get_clientdata(client);
+
+       device_remove_file(drvdata->led_dev.dev, &dev_attr_mode);
+       led_classdev_unregister(&drvdata->led_dev);
+       kfree(drvdata);
+       return 0;
+}
+
+static const struct i2c_device_id lm3530_id[] = {
+       {LM3530_NAME, 0},
+       {}
+};
+
+static struct i2c_driver lm3530_i2c_driver = {
+       .probe = lm3530_probe,
+       .remove = lm3530_remove,
+       .id_table = lm3530_id,
+       .driver = {
+               .name = LM3530_NAME,
+               .owner = THIS_MODULE,
+       },
+};
+
+static int __init lm3530_init(void)
+{
+       return i2c_add_driver(&lm3530_i2c_driver);
+}
+
+static void __exit lm3530_exit(void)
+{
+       i2c_del_driver(&lm3530_i2c_driver);
+}
+
+module_init(lm3530_init);
+module_exit(lm3530_exit);
+
+MODULE_DESCRIPTION("Back Light driver for LM3530");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");
diff --git a/include/linux/led-lm3530.h b/include/linux/led-lm3530.h
new file mode 100644 (file)
index 0000000..bb69d20
--- /dev/null
@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2011 ST-Ericsson SA.
+ * Copyright (C) 2009 Motorola, Inc.
+ *
+ * License Terms: GNU General Public License v2
+ *
+ * Simple driver for National Semiconductor LM35330 Backlight driver chip
+ *
+ * Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
+ * based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com>
+ */
+
+#ifndef _LINUX_LED_LM3530_H__
+#define _LINUX_LED_LM3530_H__
+
+#define LM3530_FS_CURR_5mA             (0) /* Full Scale Current */
+#define LM3530_FS_CURR_8mA             (1)
+#define LM3530_FS_CURR_12mA            (2)
+#define LM3530_FS_CURR_15mA            (3)
+#define LM3530_FS_CURR_19mA            (4)
+#define LM3530_FS_CURR_22mA            (5)
+#define LM3530_FS_CURR_26mA            (6)
+#define LM3530_FS_CURR_29mA            (7)
+
+#define LM3530_ALS_AVRG_TIME_32ms      (0) /* ALS Averaging Time */
+#define LM3530_ALS_AVRG_TIME_64ms      (1)
+#define LM3530_ALS_AVRG_TIME_128ms     (2)
+#define LM3530_ALS_AVRG_TIME_256ms     (3)
+#define LM3530_ALS_AVRG_TIME_512ms     (4)
+#define LM3530_ALS_AVRG_TIME_1024ms    (5)
+#define LM3530_ALS_AVRG_TIME_2048ms    (6)
+#define LM3530_ALS_AVRG_TIME_4096ms    (7)
+
+#define LM3530_RAMP_TIME_1ms           (0) /* Brigtness Ramp Time */
+#define LM3530_RAMP_TIME_130ms         (1) /* Max to 0 and vice versa */
+#define LM3530_RAMP_TIME_260ms         (2)
+#define LM3530_RAMP_TIME_520ms         (3)
+#define LM3530_RAMP_TIME_1s            (4)
+#define LM3530_RAMP_TIME_2s            (5)
+#define LM3530_RAMP_TIME_4s            (6)
+#define LM3530_RAMP_TIME_8s            (7)
+
+/* ALS Resistor Select */
+#define LM3530_ALS_IMPD_Z              (0x00) /* ALS Impedence */
+#define LM3530_ALS_IMPD_13_53kOhm      (0x01)
+#define LM3530_ALS_IMPD_9_01kOhm       (0x02)
+#define LM3530_ALS_IMPD_5_41kOhm       (0x03)
+#define LM3530_ALS_IMPD_2_27kOhm       (0x04)
+#define LM3530_ALS_IMPD_1_94kOhm       (0x05)
+#define LM3530_ALS_IMPD_1_81kOhm       (0x06)
+#define LM3530_ALS_IMPD_1_6kOhm                (0x07)
+#define LM3530_ALS_IMPD_1_138kOhm      (0x08)
+#define LM3530_ALS_IMPD_1_05kOhm       (0x09)
+#define LM3530_ALS_IMPD_1_011kOhm      (0x0A)
+#define LM3530_ALS_IMPD_941Ohm         (0x0B)
+#define LM3530_ALS_IMPD_759Ohm         (0x0C)
+#define LM3530_ALS_IMPD_719Ohm         (0x0D)
+#define LM3530_ALS_IMPD_700Ohm         (0x0E)
+#define LM3530_ALS_IMPD_667Ohm         (0x0F)
+
+enum lm3530_mode {
+       LM3530_BL_MODE_MANUAL = 0,      /* "man" */
+       LM3530_BL_MODE_ALS,             /* "als" */
+       LM3530_BL_MODE_PWM,             /* "pwm" */
+};
+
+/* ALS input select */
+enum lm3530_als_mode {
+       LM3530_INPUT_AVRG = 0,  /* ALS1 and ALS2 input average */
+       LM3530_INPUT_ALS1,      /* ALS1 Input */
+       LM3530_INPUT_ALS2,      /* ALS2 Input */
+       LM3530_INPUT_CEIL,      /* Max of ALS1 and ALS2 */
+};
+
+/**
+ * struct lm3530_platform_data
+ * @mode: mode of operation i.e. Manual, ALS or PWM
+ * @als_input_mode: select source of ALS input - ALS1/2 or average
+ * @max_current: full scale LED current
+ * @pwm_pol_hi: PWM input polarity - active high/active low
+ * @als_avrg_time: ALS input averaging time
+ * @brt_ramp_law: brightness mapping mode - exponential/linear
+ * @brt_ramp_fall: rate of fall of led current
+ * @brt_ramp_rise: rate of rise of led current
+ * @als1_resistor_sel: internal resistance from ALS1 input to ground
+ * @als2_resistor_sel: internal resistance from ALS2 input to ground
+ * @brt_val: brightness value (0-255)
+ */
+struct lm3530_platform_data {
+       enum lm3530_mode mode;
+       enum lm3530_als_mode als_input_mode;
+
+       u8 max_current;
+       bool pwm_pol_hi;
+       u8 als_avrg_time;
+
+       bool brt_ramp_law;
+       u8 brt_ramp_fall;
+       u8 brt_ramp_rise;
+
+       u8 als1_resistor_sel;
+       u8 als2_resistor_sel;
+
+       u8 brt_val;
+};
+
+#endif /* _LINUX_LED_LM3530_H__ */