[media] lm3646: add new dual LED Flash driver

This patch adds the driver for the LM3646, dual LED Flash driver.
The LM3646 has two 1.5A sync. boost converter with dual white current source.
It is controlled via an I2C compatible interface.
Each flash brightness, torch brightness and enable/disable can be controlled.
Under voltage, input voltage monitor and thermal threshhold Faults are added.
Please refer the datasheet http://www.ti.com/lit/ds/snvs962/snvs962.pdf

Signed-off-by: Daniel Jeong <gshark.jeong@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

1 files changed, 414 insertions, 0 deletions

diff --git a/drivers/media/i2c/lm3646.c b/drivers/media/i2c/lm3646.c
new file mode 100644
index 000000000000..626fb4679c02
--- /dev/null
+++ b/drivers/media/i2c/lm3646.c
@@ -0,0 +1,414 @@
+/*
+ * drivers/media/i2c/lm3646.c
+ * General device driver for TI lm3646, Dual FLASH LED Driver
+ *
+ * Copyright (C) 2014 Texas Instruments
+ *
+ * Contact: Daniel Jeong <gshark.jeong@gmail.com>
+ *			Ldd-Mlp <ldd-mlp@list.ti.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/delay.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/regmap.h>
+#include <linux/videodev2.h>
+#include <media/lm3646.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+
+/* registers definitions */
+#define REG_ENABLE		0x01
+#define REG_TORCH_BR	0x05
+#define REG_FLASH_BR	0x05
+#define REG_FLASH_TOUT	0x04
+#define REG_FLAG		0x08
+#define REG_STROBE_SRC	0x06
+#define REG_LED1_FLASH_BR 0x06
+#define REG_LED1_TORCH_BR 0x07
+
+#define MASK_ENABLE		0x03
+#define MASK_TORCH_BR	0x70
+#define MASK_FLASH_BR	0x0F
+#define MASK_FLASH_TOUT	0x07
+#define MASK_FLAG		0xFF
+#define MASK_STROBE_SRC	0x80
+
+/* Fault Mask */
+#define FAULT_TIMEOUT	(1<<0)
+#define FAULT_SHORT_CIRCUIT	(1<<1)
+#define FAULT_UVLO		(1<<2)
+#define FAULT_IVFM		(1<<3)
+#define FAULT_OCP		(1<<4)
+#define FAULT_OVERTEMP	(1<<5)
+#define FAULT_NTC_TRIP	(1<<6)
+#define FAULT_OVP		(1<<7)
+
+enum led_mode {
+	MODE_SHDN = 0x0,
+	MODE_TORCH = 0x2,
+	MODE_FLASH = 0x3,
+};
+
+/*
+ * struct lm3646_flash
+ *
+ * @pdata: platform data
+ * @regmap: reg. map for i2c
+ * @lock: muxtex for serial access.
+ * @led_mode: V4L2 LED mode
+ * @ctrls_led: V4L2 contols
+ * @subdev_led: V4L2 subdev
+ * @mode_reg : mode register value
+ */
+struct lm3646_flash {
+	struct device *dev;
+	struct lm3646_platform_data *pdata;
+	struct regmap *regmap;
+
+	struct v4l2_ctrl_handler ctrls_led;
+	struct v4l2_subdev subdev_led;
+
+	u8 mode_reg;
+};
+
+#define to_lm3646_flash(_ctrl)	\
+	container_of(_ctrl->handler, struct lm3646_flash, ctrls_led)
+
+/* enable mode control */
+static int lm3646_mode_ctrl(struct lm3646_flash *flash,
+			    enum v4l2_flash_led_mode led_mode)
+{
+	switch (led_mode) {
+	case V4L2_FLASH_LED_MODE_NONE:
+		return regmap_write(flash->regmap,
+				    REG_ENABLE, flash->mode_reg | MODE_SHDN);
+	case V4L2_FLASH_LED_MODE_TORCH:
+		return regmap_write(flash->regmap,
+				    REG_ENABLE, flash->mode_reg | MODE_TORCH);
+	case V4L2_FLASH_LED_MODE_FLASH:
+		return regmap_write(flash->regmap,
+				    REG_ENABLE, flash->mode_reg | MODE_FLASH);
+	}
+	return -EINVAL;
+}
+
+/* V4L2 controls  */
+static int lm3646_get_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct lm3646_flash *flash = to_lm3646_flash(ctrl);
+	unsigned int reg_val;
+	int rval;
+
+	if (ctrl->id != V4L2_CID_FLASH_FAULT)
+		return -EINVAL;
+
+	rval = regmap_read(flash->regmap, REG_FLAG, &reg_val);
+	if (rval < 0)
+		return rval;
+
+	ctrl->val = 0;
+	if (reg_val & FAULT_TIMEOUT)
+		ctrl->val |= V4L2_FLASH_FAULT_TIMEOUT;
+	if (reg_val & FAULT_SHORT_CIRCUIT)
+		ctrl->val |= V4L2_FLASH_FAULT_SHORT_CIRCUIT;
+	if (reg_val & FAULT_UVLO)
+		ctrl->val |= V4L2_FLASH_FAULT_UNDER_VOLTAGE;
+	if (reg_val & FAULT_IVFM)
+		ctrl->val |= V4L2_FLASH_FAULT_INPUT_VOLTAGE;
+	if (reg_val & FAULT_OCP)
+		ctrl->val |= V4L2_FLASH_FAULT_OVER_CURRENT;
+	if (reg_val & FAULT_OVERTEMP)
+		ctrl->val |= V4L2_FLASH_FAULT_OVER_TEMPERATURE;
+	if (reg_val & FAULT_NTC_TRIP)
+		ctrl->val |= V4L2_FLASH_FAULT_LED_OVER_TEMPERATURE;
+	if (reg_val & FAULT_OVP)
+		ctrl->val |= V4L2_FLASH_FAULT_OVER_VOLTAGE;
+
+	return 0;
+}
+
+static int lm3646_set_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct lm3646_flash *flash = to_lm3646_flash(ctrl);
+	unsigned int reg_val;
+	int rval = -EINVAL;
+
+	switch (ctrl->id) {
+	case V4L2_CID_FLASH_LED_MODE:
+
+		if (ctrl->val != V4L2_FLASH_LED_MODE_FLASH)
+			return lm3646_mode_ctrl(flash, ctrl->val);
+		/* switch to SHDN mode before flash strobe on */
+		return lm3646_mode_ctrl(flash, V4L2_FLASH_LED_MODE_NONE);
+
+	case V4L2_CID_FLASH_STROBE_SOURCE:
+		return regmap_update_bits(flash->regmap,
+					  REG_STROBE_SRC, MASK_STROBE_SRC,
+					  (ctrl->val) << 7);
+
+	case V4L2_CID_FLASH_STROBE:
+
+		/* read and check current mode of chip to start flash */
+		rval = regmap_read(flash->regmap, REG_ENABLE, &reg_val);
+		if (rval < 0 || ((reg_val & MASK_ENABLE) != MODE_SHDN))
+			return rval;
+		/* flash on */
+		return lm3646_mode_ctrl(flash, V4L2_FLASH_LED_MODE_FLASH);
+
+	case V4L2_CID_FLASH_STROBE_STOP:
+
+		/*
+		 * flash mode will be turned automatically
+		 * from FLASH mode to SHDN mode after flash duration timeout
+		 * read and check current mode of chip to stop flash
+		 */
+		rval = regmap_read(flash->regmap, REG_ENABLE, &reg_val);
+		if (rval < 0)
+			return rval;
+		if ((reg_val & MASK_ENABLE) == MODE_FLASH)
+			return lm3646_mode_ctrl(flash,
+						V4L2_FLASH_LED_MODE_NONE);
+		return rval;
+
+	case V4L2_CID_FLASH_TIMEOUT:
+		return regmap_update_bits(flash->regmap,
+					  REG_FLASH_TOUT, MASK_FLASH_TOUT,
+					  LM3646_FLASH_TOUT_ms_TO_REG
+					  (ctrl->val));
+
+	case V4L2_CID_FLASH_INTENSITY:
+		return regmap_update_bits(flash->regmap,
+					  REG_FLASH_BR, MASK_FLASH_BR,
+					  LM3646_TOTAL_FLASH_BRT_uA_TO_REG
+					  (ctrl->val));
+
+	case V4L2_CID_FLASH_TORCH_INTENSITY:
+		return regmap_update_bits(flash->regmap,
+					  REG_TORCH_BR, MASK_TORCH_BR,
+					  LM3646_TOTAL_TORCH_BRT_uA_TO_REG
+					  (ctrl->val) << 4);
+	}
+
+	return -EINVAL;
+}
+
+static const struct v4l2_ctrl_ops lm3646_led_ctrl_ops = {
+	.g_volatile_ctrl = lm3646_get_ctrl,
+	.s_ctrl = lm3646_set_ctrl,
+};
+
+static int lm3646_init_controls(struct lm3646_flash *flash)
+{
+	struct v4l2_ctrl *fault;
+	struct v4l2_ctrl_handler *hdl = &flash->ctrls_led;
+	const struct v4l2_ctrl_ops *ops = &lm3646_led_ctrl_ops;
+
+	v4l2_ctrl_handler_init(hdl, 8);
+	/* flash mode */
+	v4l2_ctrl_new_std_menu(hdl, ops, V4L2_CID_FLASH_LED_MODE,
+			       V4L2_FLASH_LED_MODE_TORCH, ~0x7,
+			       V4L2_FLASH_LED_MODE_NONE);
+
+	/* flash source */
+	v4l2_ctrl_new_std_menu(hdl, ops, V4L2_CID_FLASH_STROBE_SOURCE,
+			       0x1, ~0x3, V4L2_FLASH_STROBE_SOURCE_SOFTWARE);
+
+	/* flash strobe */
+	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_STROBE, 0, 0, 0, 0);
+	/* flash strobe stop */
+	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_STROBE_STOP, 0, 0, 0, 0);
+
+	/* flash strobe timeout */
+	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_TIMEOUT,
+			  LM3646_FLASH_TOUT_MIN,
+			  LM3646_FLASH_TOUT_MAX,
+			  LM3646_FLASH_TOUT_STEP, flash->pdata->flash_timeout);
+
+	/* max flash current */
+	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_INTENSITY,
+			  LM3646_TOTAL_FLASH_BRT_MIN,
+			  LM3646_TOTAL_FLASH_BRT_MAX,
+			  LM3646_TOTAL_FLASH_BRT_STEP,
+			  LM3646_TOTAL_FLASH_BRT_MAX);
+
+	/* max torch current */
+	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_TORCH_INTENSITY,
+			  LM3646_TOTAL_TORCH_BRT_MIN,
+			  LM3646_TOTAL_TORCH_BRT_MAX,
+			  LM3646_TOTAL_TORCH_BRT_STEP,
+			  LM3646_TOTAL_TORCH_BRT_MAX);
+
+	/* fault */
+	fault = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_FAULT, 0,
+				  V4L2_FLASH_FAULT_OVER_VOLTAGE
+				  | V4L2_FLASH_FAULT_OVER_TEMPERATURE
+				  | V4L2_FLASH_FAULT_SHORT_CIRCUIT
+				  | V4L2_FLASH_FAULT_TIMEOUT, 0, 0);
+	if (fault != NULL)
+		fault->flags |= V4L2_CTRL_FLAG_VOLATILE;
+
+	if (hdl->error)
+		return hdl->error;
+
+	flash->subdev_led.ctrl_handler = hdl;
+	return 0;
+}
+
+/* initialize device */
+static const struct v4l2_subdev_ops lm3646_ops = {
+	.core = NULL,
+};
+
+static const struct regmap_config lm3646_regmap = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0xFF,
+};
+
+static int lm3646_subdev_init(struct lm3646_flash *flash)
+{
+	struct i2c_client *client = to_i2c_client(flash->dev);
+	int rval;
+
+	v4l2_i2c_subdev_init(&flash->subdev_led, client, &lm3646_ops);
+	flash->subdev_led.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+	strcpy(flash->subdev_led.name, LM3646_NAME);
+	rval = lm3646_init_controls(flash);
+	if (rval)
+		goto err_out;
+	rval = media_entity_init(&flash->subdev_led.entity, 0, NULL, 0);
+	if (rval < 0)
+		goto err_out;
+	flash->subdev_led.entity.type = MEDIA_ENT_T_V4L2_SUBDEV_FLASH;
+	return rval;
+
+err_out:
+	v4l2_ctrl_handler_free(&flash->ctrls_led);
+	return rval;
+}
+
+static int lm3646_init_device(struct lm3646_flash *flash)
+{
+	unsigned int reg_val;
+	int rval;
+
+	/* read the value of mode register to reduce redundant i2c accesses */
+	rval = regmap_read(flash->regmap, REG_ENABLE, &reg_val);
+	if (rval < 0)
+		return rval;
+	flash->mode_reg = reg_val & 0xfc;
+
+	/* output disable */
+	rval = lm3646_mode_ctrl(flash, V4L2_FLASH_LED_MODE_NONE);
+	if (rval < 0)
+		return rval;
+
+	/*
+	 * LED1 flash current setting
+	 * LED2 flash current = Total(Max) flash current - LED1 flash current
+	 */
+	rval = regmap_update_bits(flash->regmap,
+				  REG_LED1_FLASH_BR, 0x7F,
+				  LM3646_LED1_FLASH_BRT_uA_TO_REG
+				  (flash->pdata->led1_flash_brt));
+
+	if (rval < 0)
+		return rval;
+
+	/*
+	 * LED1 torch current setting
+	 * LED2 torch current = Total(Max) torch current - LED1 torch current
+	 */
+	rval = regmap_update_bits(flash->regmap,
+				  REG_LED1_TORCH_BR, 0x7F,
+				  LM3646_LED1_TORCH_BRT_uA_TO_REG
+				  (flash->pdata->led1_torch_brt));
+	if (rval < 0)
+		return rval;
+
+	/* Reset flag register */
+	return regmap_read(flash->regmap, REG_FLAG, &reg_val);
+}
+
+static int lm3646_probe(struct i2c_client *client,
+			const struct i2c_device_id *devid)
+{
+	struct lm3646_flash *flash;
+	struct lm3646_platform_data *pdata = dev_get_platdata(&client->dev);
+	int rval;
+
+	flash = devm_kzalloc(&client->dev, sizeof(*flash), GFP_KERNEL);
+	if (flash == NULL)
+		return -ENOMEM;
+
+	flash->regmap = devm_regmap_init_i2c(client, &lm3646_regmap);
+	if (IS_ERR(flash->regmap))
+		return PTR_ERR(flash->regmap);
+
+	/* check device tree if there is no platform data */
+	if (pdata == NULL) {
+		pdata = devm_kzalloc(&client->dev,
+				     sizeof(struct lm3646_platform_data),
+				     GFP_KERNEL);
+		if (pdata == NULL)
+			return -ENOMEM;
+		/* use default data in case of no platform data */
+		pdata->flash_timeout = LM3646_FLASH_TOUT_MAX;
+		pdata->led1_torch_brt = LM3646_LED1_TORCH_BRT_MAX;
+		pdata->led1_flash_brt = LM3646_LED1_FLASH_BRT_MAX;
+	}
+	flash->pdata = pdata;
+	flash->dev = &client->dev;
+
+	rval = lm3646_subdev_init(flash);
+	if (rval < 0)
+		return rval;
+
+	rval = lm3646_init_device(flash);
+	if (rval < 0)
+		return rval;
+
+	i2c_set_clientdata(client, flash);
+
+	return 0;
+}
+
+static int lm3646_remove(struct i2c_client *client)
+{
+	struct lm3646_flash *flash = i2c_get_clientdata(client);
+
+	v4l2_device_unregister_subdev(&flash->subdev_led);
+	v4l2_ctrl_handler_free(&flash->ctrls_led);
+	media_entity_cleanup(&flash->subdev_led.entity);
+
+	return 0;
+}
+
+static const struct i2c_device_id lm3646_id_table[] = {
+	{LM3646_NAME, 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(i2c, lm3646_id_table);
+
+static struct i2c_driver lm3646_i2c_driver = {
+	.driver = {
+		   .name = LM3646_NAME,
+		   },
+	.probe = lm3646_probe,
+	.remove = lm3646_remove,
+	.id_table = lm3646_id_table,
+};
+
+module_i2c_driver(lm3646_i2c_driver);
+
+MODULE_AUTHOR("Daniel Jeong <gshark.jeong@gmail.com>");
+MODULE_AUTHOR("Ldd Mlp <ldd-mlp@list.ti.com>");
+MODULE_DESCRIPTION("Texas Instruments LM3646 Dual Flash LED driver");
+MODULE_LICENSE("GPL");