leds: support new LP8501 device - another LP55xx common

LP8501 can drive up to 9 channels like LP5523.
LEDs can be controlled directly via the I2C and programmable engines are
supported.

LP55xx common driver
 LP8501 is one of LP55xx family device, so LP55xx common code are used.
 Chip specific data is defined in the structure, 'lp55xx_device_config'.

Differences between LP8501 and LP5523
 Different register layout for LED output control and others.
 LP8501 specific feature for separate output power selection.
 LP8501 doesn't support external clock detection.
 Different programming engine data.

LP8501 specific feature - output power selection
 Output channels are selected by power selection - Vout or Vdd.
 Separate power for VDD1-6 and VDD7-9 are available.
 It is configurable in the platform data.
 To support this feature, LP55xx DT structure and header are changed.
 Device tree binding is updated as well.

LED pattern data
 Example pattern data is updated in the driver documentation.

Signed-off-by: Milo Kim <milo.kim@ti.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

1 files changed, 410 insertions, 0 deletions

diff --git a/drivers/leds/leds-lp8501.c b/drivers/leds/leds-lp8501.c
new file mode 100644
index 0000000..4573b94
--- /dev/null
+++ b/drivers/leds/leds-lp8501.c
@@ -0,0 +1,410 @@
+/*
+ * TI LP8501 9 channel LED Driver
+ *
+ * Copyright (C) 2013 Texas Instruments
+ *
+ * Author: Milo(Woogyom) Kim <milo.kim@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/firmware.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_data/leds-lp55xx.h>
+#include <linux/slab.h>
+
+#include "leds-lp55xx-common.h"
+
+#define LP8501_PROGRAM_LENGTH		32
+#define LP8501_MAX_LEDS			9
+
+/* Registers */
+#define LP8501_REG_ENABLE		0x00
+#define LP8501_ENABLE			BIT(6)
+#define LP8501_EXEC_M			0x3F
+#define LP8501_EXEC_ENG1_M		0x30
+#define LP8501_EXEC_ENG2_M		0x0C
+#define LP8501_EXEC_ENG3_M		0x03
+#define LP8501_RUN_ENG1			0x20
+#define LP8501_RUN_ENG2			0x08
+#define LP8501_RUN_ENG3			0x02
+
+#define LP8501_REG_OP_MODE		0x01
+#define LP8501_MODE_ENG1_M		0x30
+#define LP8501_MODE_ENG2_M		0x0C
+#define LP8501_MODE_ENG3_M		0x03
+#define LP8501_LOAD_ENG1		0x10
+#define LP8501_LOAD_ENG2		0x04
+#define LP8501_LOAD_ENG3		0x01
+
+#define LP8501_REG_PWR_CONFIG		0x05
+#define LP8501_PWR_CONFIG_M		0x03
+
+#define LP8501_REG_LED_PWM_BASE		0x16
+
+#define LP8501_REG_LED_CURRENT_BASE	0x26
+
+#define LP8501_REG_CONFIG		0x36
+#define LP8501_PWM_PSAVE		BIT(7)
+#define LP8501_AUTO_INC			BIT(6)
+#define LP8501_PWR_SAVE			BIT(5)
+#define LP8501_CP_AUTO			0x18
+#define LP8501_INT_CLK			BIT(0)
+#define LP8501_DEFAULT_CFG	\
+	(LP8501_PWM_PSAVE | LP8501_AUTO_INC | LP8501_PWR_SAVE | LP8501_CP_AUTO)
+
+#define LP8501_REG_RESET		0x3D
+#define LP8501_RESET			0xFF
+
+#define LP8501_REG_PROG_PAGE_SEL	0x4F
+#define LP8501_PAGE_ENG1		0
+#define LP8501_PAGE_ENG2		1
+#define LP8501_PAGE_ENG3		2
+
+#define LP8501_REG_PROG_MEM		0x50
+
+#define LP8501_ENG1_IS_LOADING(mode)	\
+	((mode & LP8501_MODE_ENG1_M) == LP8501_LOAD_ENG1)
+#define LP8501_ENG2_IS_LOADING(mode)	\
+	((mode & LP8501_MODE_ENG2_M) == LP8501_LOAD_ENG2)
+#define LP8501_ENG3_IS_LOADING(mode)	\
+	((mode & LP8501_MODE_ENG3_M) == LP8501_LOAD_ENG3)
+
+static inline void lp8501_wait_opmode_done(void)
+{
+	usleep_range(1000, 2000);
+}
+
+static void lp8501_set_led_current(struct lp55xx_led *led, u8 led_current)
+{
+	led->led_current = led_current;
+	lp55xx_write(led->chip, LP8501_REG_LED_CURRENT_BASE + led->chan_nr,
+		led_current);
+}
+
+static int lp8501_post_init_device(struct lp55xx_chip *chip)
+{
+	int ret;
+	u8 val = LP8501_DEFAULT_CFG;
+
+	ret = lp55xx_write(chip, LP8501_REG_ENABLE, LP8501_ENABLE);
+	if (ret)
+		return ret;
+
+	/* Chip startup time is 500 us, 1 - 2 ms gives some margin */
+	usleep_range(1000, 2000);
+
+	if (chip->pdata->clock_mode != LP55XX_CLOCK_EXT)
+		val |= LP8501_INT_CLK;
+
+	ret = lp55xx_write(chip, LP8501_REG_CONFIG, val);
+	if (ret)
+		return ret;
+
+	/* Power selection for each output */
+	return lp55xx_update_bits(chip, LP8501_REG_PWR_CONFIG,
+				LP8501_PWR_CONFIG_M, chip->pdata->pwr_sel);
+}
+
+static void lp8501_load_engine(struct lp55xx_chip *chip)
+{
+	enum lp55xx_engine_index idx = chip->engine_idx;
+	u8 mask[] = {
+		[LP55XX_ENGINE_1] = LP8501_MODE_ENG1_M,
+		[LP55XX_ENGINE_2] = LP8501_MODE_ENG2_M,
+		[LP55XX_ENGINE_3] = LP8501_MODE_ENG3_M,
+	};
+
+	u8 val[] = {
+		[LP55XX_ENGINE_1] = LP8501_LOAD_ENG1,
+		[LP55XX_ENGINE_2] = LP8501_LOAD_ENG2,
+		[LP55XX_ENGINE_3] = LP8501_LOAD_ENG3,
+	};
+
+	u8 page_sel[] = {
+		[LP55XX_ENGINE_1] = LP8501_PAGE_ENG1,
+		[LP55XX_ENGINE_2] = LP8501_PAGE_ENG2,
+		[LP55XX_ENGINE_3] = LP8501_PAGE_ENG3,
+	};
+
+	lp55xx_update_bits(chip, LP8501_REG_OP_MODE, mask[idx], val[idx]);
+
+	lp8501_wait_opmode_done();
+
+	lp55xx_write(chip, LP8501_REG_PROG_PAGE_SEL, page_sel[idx]);
+}
+
+static void lp8501_stop_engine(struct lp55xx_chip *chip)
+{
+	lp55xx_write(chip, LP8501_REG_OP_MODE, 0);
+	lp8501_wait_opmode_done();
+}
+
+static void lp8501_turn_off_channels(struct lp55xx_chip *chip)
+{
+	int i;
+
+	for (i = 0; i < LP8501_MAX_LEDS; i++)
+		lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + i, 0);
+}
+
+static void lp8501_run_engine(struct lp55xx_chip *chip, bool start)
+{
+	int ret;
+	u8 mode;
+	u8 exec;
+
+	/* stop engine */
+	if (!start) {
+		lp8501_stop_engine(chip);
+		lp8501_turn_off_channels(chip);
+		return;
+	}
+
+	/*
+	 * To run the engine,
+	 * operation mode and enable register should updated at the same time
+	 */
+
+	ret = lp55xx_read(chip, LP8501_REG_OP_MODE, &mode);
+	if (ret)
+		return;
+
+	ret = lp55xx_read(chip, LP8501_REG_ENABLE, &exec);
+	if (ret)
+		return;
+
+	/* change operation mode to RUN only when each engine is loading */
+	if (LP8501_ENG1_IS_LOADING(mode)) {
+		mode = (mode & ~LP8501_MODE_ENG1_M) | LP8501_RUN_ENG1;
+		exec = (exec & ~LP8501_EXEC_ENG1_M) | LP8501_RUN_ENG1;
+	}
+
+	if (LP8501_ENG2_IS_LOADING(mode)) {
+		mode = (mode & ~LP8501_MODE_ENG2_M) | LP8501_RUN_ENG2;
+		exec = (exec & ~LP8501_EXEC_ENG2_M) | LP8501_RUN_ENG2;
+	}
+
+	if (LP8501_ENG3_IS_LOADING(mode)) {
+		mode = (mode & ~LP8501_MODE_ENG3_M) | LP8501_RUN_ENG3;
+		exec = (exec & ~LP8501_EXEC_ENG3_M) | LP8501_RUN_ENG3;
+	}
+
+	lp55xx_write(chip, LP8501_REG_OP_MODE, mode);
+	lp8501_wait_opmode_done();
+
+	lp55xx_update_bits(chip, LP8501_REG_ENABLE, LP8501_EXEC_M, exec);
+}
+
+static int lp8501_update_program_memory(struct lp55xx_chip *chip,
+					const u8 *data, size_t size)
+{
+	u8 pattern[LP8501_PROGRAM_LENGTH] = {0};
+	unsigned cmd;
+	char c[3];
+	int update_size;
+	int nrchars;
+	int offset = 0;
+	int ret;
+	int i;
+
+	/* clear program memory before updating */
+	for (i = 0; i < LP8501_PROGRAM_LENGTH; i++)
+		lp55xx_write(chip, LP8501_REG_PROG_MEM + i, 0);
+
+	i = 0;
+	while ((offset < size - 1) && (i < LP8501_PROGRAM_LENGTH)) {
+		/* separate sscanfs because length is working only for %s */
+		ret = sscanf(data + offset, "%2s%n ", c, &nrchars);
+		if (ret != 1)
+			goto err;
+
+		ret = sscanf(c, "%2x", &cmd);
+		if (ret != 1)
+			goto err;
+
+		pattern[i] = (u8)cmd;
+		offset += nrchars;
+		i++;
+	}
+
+	/* Each instruction is 16bit long. Check that length is even */
+	if (i % 2)
+		goto err;
+
+	update_size = i;
+	for (i = 0; i < update_size; i++)
+		lp55xx_write(chip, LP8501_REG_PROG_MEM + i, pattern[i]);
+
+	return 0;
+
+err:
+	dev_err(&chip->cl->dev, "wrong pattern format\n");
+	return -EINVAL;
+}
+
+static void lp8501_firmware_loaded(struct lp55xx_chip *chip)
+{
+	const struct firmware *fw = chip->fw;
+
+	if (fw->size > LP8501_PROGRAM_LENGTH) {
+		dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
+			fw->size);
+		return;
+	}
+
+	/*
+	 * Program momery sequence
+	 *  1) set engine mode to "LOAD"
+	 *  2) write firmware data into program memory
+	 */
+
+	lp8501_load_engine(chip);
+	lp8501_update_program_memory(chip, fw->data, fw->size);
+}
+
+static void lp8501_led_brightness_work(struct work_struct *work)
+{
+	struct lp55xx_led *led = container_of(work, struct lp55xx_led,
+					      brightness_work);
+	struct lp55xx_chip *chip = led->chip;
+
+	mutex_lock(&chip->lock);
+	lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + led->chan_nr,
+		     led->brightness);
+	mutex_unlock(&chip->lock);
+}
+
+/* Chip specific configurations */
+static struct lp55xx_device_config lp8501_cfg = {
+	.reset = {
+		.addr = LP8501_REG_RESET,
+		.val  = LP8501_RESET,
+	},
+	.enable = {
+		.addr = LP8501_REG_ENABLE,
+		.val  = LP8501_ENABLE,
+	},
+	.max_channel  = LP8501_MAX_LEDS,
+	.post_init_device   = lp8501_post_init_device,
+	.brightness_work_fn = lp8501_led_brightness_work,
+	.set_led_current    = lp8501_set_led_current,
+	.firmware_cb        = lp8501_firmware_loaded,
+	.run_engine         = lp8501_run_engine,
+};
+
+static int lp8501_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	int ret;
+	struct lp55xx_chip *chip;
+	struct lp55xx_led *led;
+	struct lp55xx_platform_data *pdata;
+	struct device_node *np = client->dev.of_node;
+
+	if (!client->dev.platform_data) {
+		if (np) {
+			ret = lp55xx_of_populate_pdata(&client->dev, np);
+			if (ret < 0)
+				return ret;
+		} else {
+			dev_err(&client->dev, "no platform data\n");
+			return -EINVAL;
+		}
+	}
+	pdata = client->dev.platform_data;
+
+	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	led = devm_kzalloc(&client->dev,
+			sizeof(*led) * pdata->num_channels, GFP_KERNEL);
+	if (!led)
+		return -ENOMEM;
+
+	chip->cl = client;
+	chip->pdata = pdata;
+	chip->cfg = &lp8501_cfg;
+
+	mutex_init(&chip->lock);
+
+	i2c_set_clientdata(client, led);
+
+	ret = lp55xx_init_device(chip);
+	if (ret)
+		goto err_init;
+
+	dev_info(&client->dev, "%s Programmable led chip found\n", id->name);
+
+	ret = lp55xx_register_leds(led, chip);
+	if (ret)
+		goto err_register_leds;
+
+	ret = lp55xx_register_sysfs(chip);
+	if (ret) {
+		dev_err(&client->dev, "registering sysfs failed\n");
+		goto err_register_sysfs;
+	}
+
+	return 0;
+
+err_register_sysfs:
+	lp55xx_unregister_leds(led, chip);
+err_register_leds:
+	lp55xx_deinit_device(chip);
+err_init:
+	return ret;
+}
+
+static int lp8501_remove(struct i2c_client *client)
+{
+	struct lp55xx_led *led = i2c_get_clientdata(client);
+	struct lp55xx_chip *chip = led->chip;
+
+	lp8501_stop_engine(chip);
+	lp55xx_unregister_sysfs(chip);
+	lp55xx_unregister_leds(led, chip);
+	lp55xx_deinit_device(chip);
+
+	return 0;
+}
+
+static const struct i2c_device_id lp8501_id[] = {
+	{ "lp8501",  0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, lp8501_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id of_lp8501_leds_match[] = {
+	{ .compatible = "ti,lp8501", },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, of_lp8501_leds_match);
+#endif
+
+static struct i2c_driver lp8501_driver = {
+	.driver = {
+		.name	= "lp8501",
+		.of_match_table = of_match_ptr(of_lp8501_leds_match),
+	},
+	.probe		= lp8501_probe,
+	.remove		= lp8501_remove,
+	.id_table	= lp8501_id,
+};
+
+module_i2c_driver(lp8501_driver);
+
+MODULE_DESCRIPTION("Texas Instruments LP8501 LED drvier");
+MODULE_AUTHOR("Milo Kim");
+MODULE_LICENSE("GPL");