leds: LED driver for TI LP3952 6-Channel Color LED

The chip can drive 2 sets of RGB leds. Controller can
be controlled via PWM, I2C and audio synchronisation.
This driver uses I2C to communicate with the chip.

Datasheet: http://www.ti.com/lit/gpn/lp3952

Signed-off-by: Tony Makkiel <tony.makkiel@daqri.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

3 files changed, 316 insertions, 0 deletions

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 5ae28340a98b..9dcc9b13d495 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -228,6 +228,20 @@ config LEDS_LP3944
           To compile this driver as a module, choose M here: the
           module will be called leds-lp3944.
 
+config LEDS_LP3952
+        tristate "LED Support for TI LP3952 2 channel LED driver"
+        depends on LEDS_CLASS
+        depends on I2C
+        depends on ACPI
+        depends on GPIOLIB
+        select REGMAP_I2C
+        help
+          This option enables support for LEDs connected to the Texas
+          Instruments LP3952 LED driver.
+
+          To compile this driver as a module, choose M here: the
+          module will be called leds-lp3952.
+
 config LEDS_LP55XX_COMMON
         tristate "Common Driver for TI/National LP5521/5523/55231/5562/8501"
         depends on LEDS_LP5521 || LEDS_LP5523 || LEDS_LP5562 || LEDS_LP8501
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index cb2013df52d9..0684c865a1c0 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_LEDS_PCA9532)		+= leds-pca9532.o
 obj-$(CONFIG_LEDS_GPIO_REGISTER)        += leds-gpio-register.o
 obj-$(CONFIG_LEDS_GPIO)                 += leds-gpio.o
 obj-$(CONFIG_LEDS_LP3944)               += leds-lp3944.o
+obj-$(CONFIG_LEDS_LP3952)               += leds-lp3952.o
 obj-$(CONFIG_LEDS_LP55XX_COMMON)        += leds-lp55xx-common.o
 obj-$(CONFIG_LEDS_LP5521)               += leds-lp5521.o
 obj-$(CONFIG_LEDS_LP5523)               += leds-lp5523.o
diff --git a/drivers/leds/leds-lp3952.c b/drivers/leds/leds-lp3952.c
new file mode 100644
index 000000000000..a73c8ff08530
--- /dev/null
+++ b/drivers/leds/leds-lp3952.c
@@ -0,0 +1,301 @@
+/*
+ *      LED driver for TI lp3952 controller
+ *
+ *      Copyright (C) 2016, DAQRI, LLC.
+ *      Author: Tony Makkiel <tony.makkiel@daqri.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/leds.h>
+#include <linux/leds-lp3952.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/reboot.h>
+#include <linux/regmap.h>
+
+static int lp3952_register_write(struct i2c_client *client, u8 reg, u8 val)
+{
+        int ret;
+        struct lp3952_led_array *priv = i2c_get_clientdata(client);
+
+        ret = regmap_write(priv->regmap, reg, val);
+
+        if (ret)
+                dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
+                        __func__, reg, val, ret);
+        return ret;
+}
+
+static void lp3952_on_off(struct lp3952_led_array *priv,
+                          enum lp3952_leds led_id, bool on)
+{
+        int ret, val;
+
+        dev_dbg(&priv->client->dev, "%s LED %d to %d\n", __func__, led_id, on);
+
+        val = 1 << led_id;
+        if (led_id == LP3952_LED_ALL)
+                val = LP3952_LED_MASK_ALL;
+
+        ret = regmap_update_bits(priv->regmap, LP3952_REG_LED_CTRL, val,
+                                 on ? val : 0);
+        if (ret)
+                dev_err(&priv->client->dev, "%s, Error %d\n", __func__, ret);
+}
+
+/*
+ * Using Imax to control brightness. There are 4 possible
+ * setting 25, 50, 75 and 100 % of Imax. Possible values are
+ * values 0-4. 0 meaning turn off.
+ */
+static int lp3952_set_brightness(struct led_classdev *cdev,
+                                 enum led_brightness value)
+{
+        unsigned int reg, shift_val;
+        struct lp3952_ctrl_hdl *led = container_of(cdev,
+                                                   struct lp3952_ctrl_hdl,
+                                                   cdev);
+        struct lp3952_led_array *priv = (struct lp3952_led_array *)led->priv;
+
+        dev_dbg(cdev->dev, "Brightness request: %d on %d\n", value,
+                led->channel);
+
+        if (value == LED_OFF) {
+                lp3952_on_off(priv, led->channel, false);
+                return 0;
+        }
+
+        if (led->channel > LP3952_RED_1) {
+                dev_err(cdev->dev, " %s Invalid LED requested", __func__);
+                return -EINVAL;
+        }
+
+        if (led->channel >= LP3952_BLUE_1) {
+                reg = LP3952_REG_RGB1_MAX_I_CTRL;
+                shift_val = (led->channel - LP3952_BLUE_1) * 2;
+        } else {
+                reg = LP3952_REG_RGB2_MAX_I_CTRL;
+                shift_val = led->channel * 2;
+        }
+
+        /* Enable the LED in case it is not enabled already */
+        lp3952_on_off(priv, led->channel, true);
+
+        return regmap_update_bits(priv->regmap, reg, 3 << shift_val,
+                                  --value << shift_val);
+}
+
+static int lp3952_get_label(struct device *dev, const char *label, char *dest)
+{
+        int ret;
+        const char *str;
+
+        ret = device_property_read_string(dev, label, &str);
+        if (!ret)
+                strncpy(dest, str, LP3952_LABEL_MAX_LEN);
+
+        return ret;
+}
+
+static int lp3952_register_led_classdev(struct lp3952_led_array *priv)
+{
+        int i, acpi_ret, ret = -ENODEV;
+        static const char *led_name_hdl[LP3952_LED_ALL] = {
+                "blue2",
+                "green2",
+                "red2",
+                "blue1",
+                "green1",
+                "red1"
+        };
+
+        for (i = 0; i < LP3952_LED_ALL; i++) {
+                acpi_ret = lp3952_get_label(&priv->client->dev, led_name_hdl[i],
+                                            priv->leds[i].name);
+                if (acpi_ret)
+                        continue;
+
+                priv->leds[i].cdev.name = priv->leds[i].name;
+                priv->leds[i].cdev.brightness = LED_OFF;
+                priv->leds[i].cdev.max_brightness = LP3952_BRIGHT_MAX;
+                priv->leds[i].cdev.brightness_set_blocking =
+                                lp3952_set_brightness;
+                priv->leds[i].channel = i;
+                priv->leds[i].priv = priv;
+
+                ret = devm_led_classdev_register(&priv->client->dev,
+                                                 &priv->leds[i].cdev);
+                if (ret < 0) {
+                        dev_err(&priv->client->dev,
+                                "couldn't register LED %s\n",
+                                priv->leds[i].cdev.name);
+                        break;
+                }
+        }
+        return ret;
+}
+
+static int lp3952_set_pattern_gen_cmd(struct lp3952_led_array *priv,
+                                      u8 cmd_index, u8 r, u8 g, u8 b,
+                                      enum lp3952_tt tt, enum lp3952_cet cet)
+{
+        int ret;
+        struct ptrn_gen_cmd line = {
+                {
+                        {
+                                .r = r,
+                                .g = g,
+                                .b = b,
+                                .cet = cet,
+                                .tt = tt
+                        }
+                }
+        };
+
+        if (cmd_index >= LP3952_CMD_REG_COUNT)
+                return -EINVAL;
+
+        ret = lp3952_register_write(priv->client,
+                                    LP3952_REG_CMD_0 + cmd_index * 2,
+                                    line.bytes.msb);
+        if (ret)
+                return ret;
+
+        return lp3952_register_write(priv->client,
+                                      LP3952_REG_CMD_0 + cmd_index * 2 + 1,
+                                      line.bytes.lsb);
+}
+
+static int lp3952_configure(struct lp3952_led_array *priv)
+{
+        int ret;
+
+        /* Disable any LEDs on from any previous conf. */
+        ret = lp3952_register_write(priv->client, LP3952_REG_LED_CTRL, 0);
+        if (ret)
+                return ret;
+
+        /* enable rgb patter, loop */
+        ret = lp3952_register_write(priv->client, LP3952_REG_PAT_GEN_CTRL,
+                                    LP3952_PATRN_LOOP | LP3952_PATRN_GEN_EN);
+        if (ret)
+                return ret;
+
+        /* Update Bit 6 (Active mode), Select both Led sets, Bit [1:0] */
+        ret = lp3952_register_write(priv->client, LP3952_REG_ENABLES,
+                                    LP3952_ACTIVE_MODE | LP3952_INT_B00ST_LDR);
+        if (ret)
+                return ret;
+
+        /* Set Cmd1 for RGB intensity,cmd and transition time */
+        return lp3952_set_pattern_gen_cmd(priv, 0, I46, I71, I100, TT0,
+                                           CET197);
+}
+
+static const struct regmap_config lp3952_regmap = {
+        .reg_bits = 8,
+        .val_bits = 8,
+        .max_register = REG_MAX,
+        .cache_type = REGCACHE_RBTREE,
+};
+
+static int lp3952_probe(struct i2c_client *client,
+                        const struct i2c_device_id *id)
+{
+        int status;
+        struct lp3952_led_array *priv;
+
+        priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
+        if (!priv)
+                return -ENOMEM;
+
+        priv->client = client;
+
+        priv->enable_gpio = devm_gpiod_get(&client->dev, "nrst",
+                                           GPIOD_OUT_HIGH);
+        if (IS_ERR(priv->enable_gpio)) {
+                status = PTR_ERR(priv->enable_gpio);
+                dev_err(&client->dev, "Failed to enable gpio: %d\n", status);
+                return status;
+        }
+
+        priv->regmap = devm_regmap_init_i2c(client, &lp3952_regmap);
+        if (IS_ERR(priv->regmap)) {
+                int err = PTR_ERR(priv->regmap);
+
+                dev_err(&client->dev, "Failed to allocate register map: %d\n",
+                        err);
+                return err;
+        }
+
+        i2c_set_clientdata(client, priv);
+
+        status = lp3952_configure(priv);
+        if (status) {
+                dev_err(&client->dev, "Probe failed. Device not found (%d)\n",
+                        status);
+                return status;
+        }
+
+        status = lp3952_register_led_classdev(priv);
+        if (status) {
+                dev_err(&client->dev, "Unable to register led_classdev: %d\n",
+                        status);
+                return status;
+        }
+
+        return 0;
+}
+
+static int lp3952_remove(struct i2c_client *client)
+{
+        struct lp3952_led_array *priv;
+
+        priv = i2c_get_clientdata(client);
+        lp3952_on_off(priv, LP3952_LED_ALL, false);
+        gpiod_set_value(priv->enable_gpio, 0);
+
+        return 0;
+}
+
+static const struct i2c_device_id lp3952_id[] = {
+        {LP3952_NAME, 0},
+        {}
+};
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id lp3952_acpi_match[] = {
+        {"TXNW3952", 0},
+        {}
+};
+
+MODULE_DEVICE_TABLE(acpi, lp3952_acpi_match);
+#endif
+
+static struct i2c_driver lp3952_i2c_driver = {
+        .driver = {
+                        .name = LP3952_NAME,
+                        .acpi_match_table = ACPI_PTR(lp3952_acpi_match),
+        },
+        .probe = lp3952_probe,
+        .remove = lp3952_remove,
+        .id_table = lp3952_id,
+};
+
+module_i2c_driver(lp3952_i2c_driver);
+
+MODULE_AUTHOR("Tony Makkiel <tony.makkiel@daqri.com>");
+MODULE_DESCRIPTION("lp3952 I2C LED controller driver");
+MODULE_LICENSE("GPL v2");