--- /dev/null
+/*
+ * 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>
+#include <linux/regulator/consumer.h>
+#include <linux/module.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_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 14
+
+/* 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_ALS_ZB_MAX (4)
+#define LM3530_ALS_WINDOW_mV (1000)
+#define LM3530_ALS_OFFSET_mV (4)
+
+/* Zone Target Register defaults */
+#define LM3530_DEF_ZT_0 (0x7F)
+#define LM3530_DEF_ZT_1 (0x66)
+#define LM3530_DEF_ZT_2 (0x4C)
+#define LM3530_DEF_ZT_3 (0x33)
+#define LM3530_DEF_ZT_4 (0x19)
+
+/* 7 bits are used for the brightness : LM3530_BRT_CTRL_REG */
+#define MAX_BRIGHTNESS (127)
+
+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
+ * @regulator: regulator
+ * @brighness: previous brightness value
+ * @enable: regulator is enabled
+ */
+struct lm3530_data {
+ struct led_classdev led_dev;
+ struct i2c_client *client;
+ struct lm3530_platform_data *pdata;
+ enum lm3530_mode mode;
+ struct regulator *regulator;
+ enum led_brightness brightness;
+ bool enable;
+};
+
+/*
+ * struct lm3530_als_data
+ * @config : value of ALS configuration register
+ * @imp_sel : value of ALS resistor select register
+ * @zone : values of ALS ZB(Zone Boundary) registers
+ */
+struct lm3530_als_data {
+ u8 config;
+ u8 imp_sel;
+ u8 zones[LM3530_ALS_ZB_MAX];
+};
+
+static const u8 lm3530_reg[LM3530_REG_MAX] = {
+ LM3530_GEN_CONFIG,
+ LM3530_ALS_CONFIG,
+ LM3530_BRT_RAMP_RATE,
+ 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 -EINVAL;
+}
+
+static void lm3530_als_configure(struct lm3530_platform_data *pdata,
+ struct lm3530_als_data *als)
+{
+ int i;
+ u32 als_vmin, als_vmax, als_vstep;
+
+ if (pdata->als_vmax == 0) {
+ pdata->als_vmin = 0;
+ pdata->als_vmax = LM3530_ALS_WINDOW_mV;
+ }
+
+ als_vmin = pdata->als_vmin;
+ als_vmax = pdata->als_vmax;
+
+ if ((als_vmax - als_vmin) > LM3530_ALS_WINDOW_mV)
+ pdata->als_vmax = als_vmax = als_vmin + LM3530_ALS_WINDOW_mV;
+
+ /* n zone boundary makes n+1 zones */
+ als_vstep = (als_vmax - als_vmin) / (LM3530_ALS_ZB_MAX + 1);
+
+ for (i = 0; i < LM3530_ALS_ZB_MAX; i++)
+ als->zones[i] = (((als_vmin + LM3530_ALS_OFFSET_mV) +
+ als_vstep + (i * als_vstep)) * LED_FULL) / 1000;
+
+ als->config =
+ (pdata->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
+ (LM3530_ENABLE_ALS) |
+ (pdata->als_input_mode << LM3530_ALS_SEL_SHIFT);
+
+ als->imp_sel =
+ (pdata->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
+ (pdata->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
+}
+
+static int lm3530_led_enable(struct lm3530_data *drvdata)
+{
+ int ret;
+
+ if (drvdata->enable)
+ return 0;
+
+ ret = regulator_enable(drvdata->regulator);
+ if (ret) {
+ dev_err(drvdata->led_dev.dev, "Failed to enable vin:%d\n", ret);
+ return ret;
+ }
+
+ drvdata->enable = true;
+ return 0;
+}
+
+static void lm3530_led_disable(struct lm3530_data *drvdata)
+{
+ int ret;
+
+ if (!drvdata->enable)
+ return;
+
+ ret = regulator_disable(drvdata->regulator);
+ if (ret) {
+ dev_err(drvdata->led_dev.dev, "Failed to disable vin:%d\n",
+ ret);
+ return;
+ }
+
+ drvdata->enable = false;
+}
+
+static int lm3530_init_registers(struct lm3530_data *drvdata)
+{
+ int ret = 0;
+ int i;
+ u8 gen_config;
+ u8 brt_ramp;
+ u8 brightness;
+ u8 reg_val[LM3530_REG_MAX];
+ struct lm3530_platform_data *pdata = drvdata->pdata;
+ struct i2c_client *client = drvdata->client;
+ struct lm3530_pwm_data *pwm = &pdata->pwm_data;
+ struct lm3530_als_data als;
+
+ memset(&als, 0, sizeof(struct lm3530_als_data));
+
+ gen_config = (pdata->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
+ ((pdata->max_current & 7) << LM3530_MAX_CURR_SHIFT);
+
+ switch (drvdata->mode) {
+ case LM3530_BL_MODE_MANUAL:
+ gen_config |= LM3530_ENABLE_I2C;
+ break;
+ case LM3530_BL_MODE_ALS:
+ gen_config |= LM3530_ENABLE_I2C;
+ lm3530_als_configure(pdata, &als);
+ break;
+ case LM3530_BL_MODE_PWM:
+ gen_config |= LM3530_ENABLE_PWM | LM3530_ENABLE_PWM_SIMPLE |
+ (pdata->pwm_pol_hi << LM3530_PWM_POL_SHIFT);
+ break;
+ }
+
+ brt_ramp = (pdata->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
+ (pdata->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);
+
+ if (drvdata->brightness)
+ brightness = drvdata->brightness;
+ else
+ brightness = drvdata->brightness = pdata->brt_val;
+
+ if (brightness > drvdata->led_dev.max_brightness)
+ brightness = drvdata->led_dev.max_brightness;
+
+ 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] = als.imp_sel; /* LM3530_ALS_IMP_SELECT */
+ reg_val[4] = brightness; /* LM3530_BRT_CTRL_REG */
+ reg_val[5] = als.zones[0]; /* LM3530_ALS_ZB0_REG */
+ reg_val[6] = als.zones[1]; /* LM3530_ALS_ZB1_REG */
+ reg_val[7] = als.zones[2]; /* LM3530_ALS_ZB2_REG */
+ reg_val[8] = als.zones[3]; /* LM3530_ALS_ZB3_REG */
+ reg_val[9] = LM3530_DEF_ZT_0; /* LM3530_ALS_Z0T_REG */
+ reg_val[10] = LM3530_DEF_ZT_1; /* LM3530_ALS_Z1T_REG */
+ reg_val[11] = LM3530_DEF_ZT_2; /* LM3530_ALS_Z2T_REG */
+ reg_val[12] = LM3530_DEF_ZT_3; /* LM3530_ALS_Z3T_REG */
+ reg_val[13] = LM3530_DEF_ZT_4; /* LM3530_ALS_Z4T_REG */
+
+ ret = lm3530_led_enable(drvdata);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < LM3530_REG_MAX; i++) {
+ /* do not update brightness register when pwm mode */
+ if (lm3530_reg[i] == LM3530_BRT_CTRL_REG &&
+ drvdata->mode == LM3530_BL_MODE_PWM) {
+ if (pwm->pwm_set_intensity)
+ pwm->pwm_set_intensity(reg_val[i],
+ drvdata->led_dev.max_brightness);
+ continue;
+ }
+
+ 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);
+ struct lm3530_platform_data *pdata = drvdata->pdata;
+ struct lm3530_pwm_data *pwm = &pdata->pwm_data;
+ u8 max_brightness = led_cdev->max_brightness;
+
+ switch (drvdata->mode) {
+ case LM3530_BL_MODE_MANUAL:
+
+ if (!drvdata->enable) {
+ err = lm3530_init_registers(drvdata);
+ if (err) {
+ dev_err(&drvdata->client->dev,
+ "Register Init failed: %d\n", err);
+ break;
+ }
+ }
+
+ /* set the brightness in brightness control register*/
+ err = i2c_smbus_write_byte_data(drvdata->client,
+ LM3530_BRT_CTRL_REG, brt_val);
+ if (err)
+ dev_err(&drvdata->client->dev,
+ "Unable to set brightness: %d\n", err);
+ else
+ drvdata->brightness = brt_val;
+
+ if (brt_val == 0)
+ lm3530_led_disable(drvdata);
+ break;
+ case LM3530_BL_MODE_ALS:
+ break;
+ case LM3530_BL_MODE_PWM:
+ if (pwm->pwm_set_intensity)
+ pwm->pwm_set_intensity(brt_val, max_brightness);
+ break;
+ default:
+ break;
+ }
+}
+
+static ssize_t lm3530_mode_get(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct lm3530_data *drvdata;
+ int i, len = 0;
+
+ drvdata = container_of(led_cdev, struct lm3530_data, led_dev);
+ for (i = 0; i < ARRAY_SIZE(mode_map); i++)
+ if (drvdata->mode == mode_map[i].mode_val)
+ len += sprintf(buf + len, "[%s] ", mode_map[i].mode);
+ else
+ len += sprintf(buf + len, "%s ", mode_map[i].mode);
+
+ len += sprintf(buf + len, "\n");
+
+ return len;
+}
+
+static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
+ *attr, const char *buf, size_t size)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct lm3530_data *drvdata;
+ struct lm3530_pwm_data *pwm;
+ u8 max_brightness;
+ int mode, err;
+
+ drvdata = container_of(led_cdev, struct lm3530_data, led_dev);
+ pwm = &drvdata->pdata->pwm_data;
+ max_brightness = led_cdev->max_brightness;
+ mode = lm3530_get_mode_from_str(buf);
+ if (mode < 0) {
+ dev_err(dev, "Invalid mode\n");
+ return mode;
+ }
+
+ drvdata->mode = mode;
+
+ /* set pwm to low if unnecessary */
+ if (mode != LM3530_BL_MODE_PWM && pwm->pwm_set_intensity)
+ pwm->pwm_set_intensity(0, max_brightness);
+
+ 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, lm3530_mode_get, lm3530_mode_set);
+
+static struct attribute *lm3530_attrs[] = {
+ &dev_attr_mode.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(lm3530);
+
+static int lm3530_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct lm3530_platform_data *pdata = dev_get_platdata(&client->dev);
+ struct lm3530_data *drvdata;
+ int err = 0;
+
+ if (pdata == NULL) {
+ dev_err(&client->dev, "platform data required\n");
+ return -ENODEV;
+ }
+
+ /* BL mode */
+ if (pdata->mode > LM3530_BL_MODE_PWM) {
+ dev_err(&client->dev, "Illegal Mode request\n");
+ return -EINVAL;
+ }
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+ dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
+ return -EIO;
+ }
+
+ drvdata = devm_kzalloc(&client->dev, sizeof(struct lm3530_data),
+ GFP_KERNEL);
+ if (drvdata == NULL)
+ return -ENOMEM;
+
+ drvdata->mode = pdata->mode;
+ drvdata->client = client;
+ drvdata->pdata = pdata;
+ drvdata->brightness = LED_OFF;
+ drvdata->enable = false;
+ drvdata->led_dev.name = LM3530_LED_DEV;
+ drvdata->led_dev.brightness_set = lm3530_brightness_set;
+ drvdata->led_dev.max_brightness = MAX_BRIGHTNESS;
+ drvdata->led_dev.groups = lm3530_groups;
+
+ i2c_set_clientdata(client, drvdata);
+
+ drvdata->regulator = devm_regulator_get(&client->dev, "vin");
+ if (IS_ERR(drvdata->regulator)) {
+ dev_err(&client->dev, "regulator get failed\n");
+ err = PTR_ERR(drvdata->regulator);
+ drvdata->regulator = NULL;
+ return err;
+ }
+
+ if (drvdata->pdata->brt_val) {
+ err = lm3530_init_registers(drvdata);
+ if (err < 0) {
+ dev_err(&client->dev,
+ "Register Init failed: %d\n", err);
+ return err;
+ }
+ }
+ err = led_classdev_register(&client->dev, &drvdata->led_dev);
+ if (err < 0) {
+ dev_err(&client->dev, "Register led class failed: %d\n", err);
+ return err;
+ }
+
+ return 0;
+}
+
+static int lm3530_remove(struct i2c_client *client)
+{
+ struct lm3530_data *drvdata = i2c_get_clientdata(client);
+
+ lm3530_led_disable(drvdata);
+ led_classdev_unregister(&drvdata->led_dev);
+ return 0;
+}
+
+static const struct i2c_device_id lm3530_id[] = {
+ {LM3530_NAME, 0},
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, lm3530_id);
+
+static struct i2c_driver lm3530_i2c_driver = {
+ .probe = lm3530_probe,
+ .remove = lm3530_remove,
+ .id_table = lm3530_id,
+ .driver = {
+ .name = LM3530_NAME,
+ .owner = THIS_MODULE,
+ },
+};
+
+module_i2c_driver(lm3530_i2c_driver);
+
+MODULE_DESCRIPTION("Back Light driver for LM3530");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");
Code Review / kvmfornfv.git / blobdiff