348 lines
		
	
	
		
			8.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			348 lines
		
	
	
		
			8.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0
 | |
| // Copyright (c) 2019 Crane Merchandising Systems. All rights reserved.
 | |
| // Copyright (C) 2019 Oleh Kravchenko <oleg@kaa.org.ua>
 | |
| 
 | |
| #include <linux/delay.h>
 | |
| #include <linux/leds.h>
 | |
| #include <linux/module.h>
 | |
| #include <linux/of_device.h>
 | |
| #include <linux/spi/spi.h>
 | |
| 
 | |
| /*
 | |
|  * EL15203000 SPI protocol description:
 | |
|  * +-----+---------+
 | |
|  * | LED | COMMAND |
 | |
|  * +-----+---------+
 | |
|  * |  1  |    1    |
 | |
|  * +-----+---------+
 | |
|  * (*) LEDs MCU board expects 20 msec delay per byte.
 | |
|  *
 | |
|  * LEDs:
 | |
|  * +----------+--------------+-------------------------------------------+
 | |
|  * |    ID    |     NAME     |         DESCRIPTION                       |
 | |
|  * +----------+--------------+-------------------------------------------+
 | |
|  * | 'P' 0x50 |     Pipe     | Consists from 5 LEDs, controlled by board |
 | |
|  * +----------+--------------+-------------------------------------------+
 | |
|  * | 'S' 0x53 | Screen frame | Light tube around the screen              |
 | |
|  * +----------+--------------+-------------------------------------------+
 | |
|  * | 'V' 0x56 | Vending area | Highlights a cup of coffee                |
 | |
|  * +----------+--------------+-------------------------------------------+
 | |
|  *
 | |
|  * COMMAND:
 | |
|  * +----------+-----------------+--------------+--------------+
 | |
|  * |  VALUES  |       PIPE      | SCREEN FRAME | VENDING AREA |
 | |
|  * +----------+-----------------+--------------+--------------+
 | |
|  * | '0' 0x30 |                      Off                      |
 | |
|  * +----------+-----------------------------------------------+
 | |
|  * | '1' 0x31 |                      On                       |
 | |
|  * +----------+-----------------+--------------+--------------+
 | |
|  * | '2' 0x32 |     Cascade     |   Breathing  |
 | |
|  * +----------+-----------------+--------------+
 | |
|  * | '3' 0x33 | Inverse cascade |
 | |
|  * +----------+-----------------+
 | |
|  * | '4' 0x34 |     Bounce      |
 | |
|  * +----------+-----------------+
 | |
|  * | '5' 0x35 | Inverse bounce  |
 | |
|  * +----------+-----------------+
 | |
|  */
 | |
| 
 | |
| /* EL15203000 default settings */
 | |
| #define EL_FW_DELAY_USEC	20000ul
 | |
| #define EL_PATTERN_DELAY_MSEC	800u
 | |
| #define EL_PATTERN_LEN		10u
 | |
| #define EL_PATTERN_HALF_LEN	(EL_PATTERN_LEN / 2)
 | |
| 
 | |
| enum el15203000_command {
 | |
| 	/* for all LEDs */
 | |
| 	EL_OFF			= '0',
 | |
| 	EL_ON			= '1',
 | |
| 
 | |
| 	/* for Screen LED */
 | |
| 	EL_SCREEN_BREATHING	= '2',
 | |
| 
 | |
| 	/* for Pipe LED */
 | |
| 	EL_PIPE_CASCADE		= '2',
 | |
| 	EL_PIPE_INV_CASCADE	= '3',
 | |
| 	EL_PIPE_BOUNCE		= '4',
 | |
| 	EL_PIPE_INV_BOUNCE	= '5',
 | |
| };
 | |
| 
 | |
| struct el15203000_led {
 | |
| 	struct led_classdev	ldev;
 | |
| 	struct el15203000	*priv;
 | |
| 	u32			reg;
 | |
| };
 | |
| 
 | |
| struct el15203000 {
 | |
| 	struct device		*dev;
 | |
| 	struct mutex		lock;
 | |
| 	struct spi_device	*spi;
 | |
| 	unsigned long		delay;
 | |
| 	size_t			count;
 | |
| 	struct el15203000_led	leds[];
 | |
| };
 | |
| 
 | |
| #define to_el15203000_led(d)	container_of(d, struct el15203000_led, ldev)
 | |
| 
 | |
| static int el15203000_cmd(struct el15203000_led *led, u8 brightness)
 | |
| {
 | |
| 	int		ret;
 | |
| 	u8		cmd[2];
 | |
| 	size_t		i;
 | |
| 
 | |
| 	mutex_lock(&led->priv->lock);
 | |
| 
 | |
| 	dev_dbg(led->priv->dev, "Set brightness of 0x%02x(%c) to 0x%02x(%c)",
 | |
| 		led->reg, led->reg, brightness, brightness);
 | |
| 
 | |
| 	/* to avoid SPI mistiming with firmware we should wait some time */
 | |
| 	if (time_after(led->priv->delay, jiffies)) {
 | |
| 		dev_dbg(led->priv->dev, "Wait %luus to sync",
 | |
| 			EL_FW_DELAY_USEC);
 | |
| 
 | |
| 		usleep_range(EL_FW_DELAY_USEC,
 | |
| 			     EL_FW_DELAY_USEC + 1);
 | |
| 	}
 | |
| 
 | |
| 	cmd[0] = led->reg;
 | |
| 	cmd[1] = brightness;
 | |
| 
 | |
| 	for (i = 0; i < ARRAY_SIZE(cmd); i++) {
 | |
| 		if (i)
 | |
| 			usleep_range(EL_FW_DELAY_USEC,
 | |
| 				     EL_FW_DELAY_USEC + 1);
 | |
| 
 | |
| 		ret = spi_write(led->priv->spi, &cmd[i], sizeof(cmd[i]));
 | |
| 		if (ret) {
 | |
| 			dev_err(led->priv->dev,
 | |
| 				"spi_write() error %d", ret);
 | |
| 			break;
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| 	led->priv->delay = jiffies + usecs_to_jiffies(EL_FW_DELAY_USEC);
 | |
| 
 | |
| 	mutex_unlock(&led->priv->lock);
 | |
| 
 | |
| 	return ret;
 | |
| }
 | |
| 
 | |
| static int el15203000_set_blocking(struct led_classdev *ldev,
 | |
| 				   enum led_brightness brightness)
 | |
| {
 | |
| 	struct el15203000_led *led = to_el15203000_led(ldev);
 | |
| 
 | |
| 	return el15203000_cmd(led, brightness == LED_OFF ? EL_OFF : EL_ON);
 | |
| }
 | |
| 
 | |
| static int el15203000_pattern_set_S(struct led_classdev *ldev,
 | |
| 				    struct led_pattern *pattern,
 | |
| 				    u32 len, int repeat)
 | |
| {
 | |
| 	struct el15203000_led *led = to_el15203000_led(ldev);
 | |
| 
 | |
| 	if (repeat > 0 || len != 2 ||
 | |
| 	    pattern[0].delta_t != 4000 || pattern[0].brightness != 0 ||
 | |
| 	    pattern[1].delta_t != 4000 || pattern[1].brightness != 1)
 | |
| 		return -EINVAL;
 | |
| 
 | |
| 	dev_dbg(led->priv->dev, "Breathing mode for 0x%02x(%c)",
 | |
| 		led->reg, led->reg);
 | |
| 
 | |
| 	return el15203000_cmd(led, EL_SCREEN_BREATHING);
 | |
| }
 | |
| 
 | |
| static bool is_cascade(const struct led_pattern *pattern, u32 len,
 | |
| 		       bool inv, bool right)
 | |
| {
 | |
| 	int val, t;
 | |
| 	u32 i;
 | |
| 
 | |
| 	if (len != EL_PATTERN_HALF_LEN)
 | |
| 		return false;
 | |
| 
 | |
| 	val = right ? BIT(4) : BIT(0);
 | |
| 
 | |
| 	for (i = 0; i < len; i++) {
 | |
| 		t = inv ? ~val & GENMASK(4, 0) : val;
 | |
| 
 | |
| 		if (pattern[i].delta_t != EL_PATTERN_DELAY_MSEC ||
 | |
| 		    pattern[i].brightness != t)
 | |
| 			return false;
 | |
| 
 | |
| 		val = right ? val >> 1 : val << 1;
 | |
| 	}
 | |
| 
 | |
| 	return true;
 | |
| }
 | |
| 
 | |
| static bool is_bounce(const struct led_pattern *pattern, u32 len, bool inv)
 | |
| {
 | |
| 	if (len != EL_PATTERN_LEN)
 | |
| 		return false;
 | |
| 
 | |
| 	return is_cascade(pattern, EL_PATTERN_HALF_LEN, inv, false) &&
 | |
| 	       is_cascade(pattern + EL_PATTERN_HALF_LEN,
 | |
| 			  EL_PATTERN_HALF_LEN, inv, true);
 | |
| }
 | |
| 
 | |
| static int el15203000_pattern_set_P(struct led_classdev *ldev,
 | |
| 				    struct led_pattern *pattern,
 | |
| 				    u32 len, int repeat)
 | |
| {
 | |
| 	struct el15203000_led	*led = to_el15203000_led(ldev);
 | |
| 	u8			cmd;
 | |
| 
 | |
| 	if (repeat > 0)
 | |
| 		return -EINVAL;
 | |
| 
 | |
| 	if (is_cascade(pattern, len, false, false)) {
 | |
| 		dev_dbg(led->priv->dev, "Cascade mode for 0x%02x(%c)",
 | |
| 			led->reg, led->reg);
 | |
| 
 | |
| 		cmd = EL_PIPE_CASCADE;
 | |
| 	} else if (is_cascade(pattern, len, true, false)) {
 | |
| 		dev_dbg(led->priv->dev, "Inverse cascade mode for 0x%02x(%c)",
 | |
| 			led->reg, led->reg);
 | |
| 
 | |
| 		cmd = EL_PIPE_INV_CASCADE;
 | |
| 	} else if (is_bounce(pattern, len, false)) {
 | |
| 		dev_dbg(led->priv->dev, "Bounce mode for 0x%02x(%c)",
 | |
| 			led->reg, led->reg);
 | |
| 
 | |
| 		cmd = EL_PIPE_BOUNCE;
 | |
| 	} else if (is_bounce(pattern, len, true)) {
 | |
| 		dev_dbg(led->priv->dev, "Inverse bounce mode for 0x%02x(%c)",
 | |
| 			led->reg, led->reg);
 | |
| 
 | |
| 		cmd = EL_PIPE_INV_BOUNCE;
 | |
| 	} else {
 | |
| 		dev_err(led->priv->dev, "Invalid hw_pattern for 0x%02x(%c)!",
 | |
| 			led->reg, led->reg);
 | |
| 
 | |
| 		return -EINVAL;
 | |
| 	}
 | |
| 
 | |
| 	return el15203000_cmd(led, cmd);
 | |
| }
 | |
| 
 | |
| static int el15203000_pattern_clear(struct led_classdev *ldev)
 | |
| {
 | |
| 	struct el15203000_led *led = to_el15203000_led(ldev);
 | |
| 
 | |
| 	return el15203000_cmd(led, EL_OFF);
 | |
| }
 | |
| 
 | |
| static int el15203000_probe_dt(struct el15203000 *priv)
 | |
| {
 | |
| 	struct el15203000_led	*led = priv->leds;
 | |
| 	struct fwnode_handle	*child;
 | |
| 	int			ret;
 | |
| 
 | |
| 	device_for_each_child_node(priv->dev, child) {
 | |
| 		struct led_init_data init_data = {};
 | |
| 
 | |
| 		ret = fwnode_property_read_u32(child, "reg", &led->reg);
 | |
| 		if (ret) {
 | |
| 			dev_err(priv->dev, "LED without ID number");
 | |
| 			goto err_child_out;
 | |
| 		}
 | |
| 
 | |
| 		if (led->reg > U8_MAX) {
 | |
| 			dev_err(priv->dev, "LED value %d is invalid", led->reg);
 | |
| 			ret = -EINVAL;
 | |
| 			goto err_child_out;
 | |
| 		}
 | |
| 
 | |
| 		led->priv			  = priv;
 | |
| 		led->ldev.max_brightness	  = LED_ON;
 | |
| 		led->ldev.brightness_set_blocking = el15203000_set_blocking;
 | |
| 
 | |
| 		if (led->reg == 'S') {
 | |
| 			led->ldev.pattern_set	= el15203000_pattern_set_S;
 | |
| 			led->ldev.pattern_clear	= el15203000_pattern_clear;
 | |
| 		} else if (led->reg == 'P') {
 | |
| 			led->ldev.pattern_set	= el15203000_pattern_set_P;
 | |
| 			led->ldev.pattern_clear	= el15203000_pattern_clear;
 | |
| 		}
 | |
| 
 | |
| 		init_data.fwnode = child;
 | |
| 		ret = devm_led_classdev_register_ext(priv->dev, &led->ldev,
 | |
| 						     &init_data);
 | |
| 		if (ret) {
 | |
| 			dev_err(priv->dev,
 | |
| 				"failed to register LED device %s, err %d",
 | |
| 				led->ldev.name, ret);
 | |
| 			goto err_child_out;
 | |
| 		}
 | |
| 
 | |
| 		led++;
 | |
| 	}
 | |
| 
 | |
| 	return 0;
 | |
| 
 | |
| err_child_out:
 | |
| 	fwnode_handle_put(child);
 | |
| 	return ret;
 | |
| }
 | |
| 
 | |
| static int el15203000_probe(struct spi_device *spi)
 | |
| {
 | |
| 	struct el15203000	*priv;
 | |
| 	size_t			count;
 | |
| 
 | |
| 	count = device_get_child_node_count(&spi->dev);
 | |
| 	if (!count) {
 | |
| 		dev_err(&spi->dev, "LEDs are not defined in device tree!");
 | |
| 		return -ENODEV;
 | |
| 	}
 | |
| 
 | |
| 	priv = devm_kzalloc(&spi->dev, struct_size(priv, leds, count),
 | |
| 			    GFP_KERNEL);
 | |
| 	if (!priv)
 | |
| 		return -ENOMEM;
 | |
| 
 | |
| 	mutex_init(&priv->lock);
 | |
| 	priv->count	= count;
 | |
| 	priv->dev	= &spi->dev;
 | |
| 	priv->spi	= spi;
 | |
| 	priv->delay	= jiffies -
 | |
| 			  usecs_to_jiffies(EL_FW_DELAY_USEC);
 | |
| 
 | |
| 	spi_set_drvdata(spi, priv);
 | |
| 
 | |
| 	return el15203000_probe_dt(priv);
 | |
| }
 | |
| 
 | |
| static int el15203000_remove(struct spi_device *spi)
 | |
| {
 | |
| 	struct el15203000 *priv = spi_get_drvdata(spi);
 | |
| 
 | |
| 	mutex_destroy(&priv->lock);
 | |
| 
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static const struct of_device_id el15203000_dt_ids[] = {
 | |
| 	{ .compatible = "crane,el15203000", },
 | |
| 	{},
 | |
| };
 | |
| 
 | |
| MODULE_DEVICE_TABLE(of, el15203000_dt_ids);
 | |
| 
 | |
| static struct spi_driver el15203000_driver = {
 | |
| 	.probe		= el15203000_probe,
 | |
| 	.remove		= el15203000_remove,
 | |
| 	.driver = {
 | |
| 		.name		= KBUILD_MODNAME,
 | |
| 		.of_match_table	= el15203000_dt_ids,
 | |
| 	},
 | |
| };
 | |
| 
 | |
| module_spi_driver(el15203000_driver);
 | |
| 
 | |
| MODULE_AUTHOR("Oleh Kravchenko <oleg@kaa.org.ua>");
 | |
| MODULE_DESCRIPTION("el15203000 LED driver");
 | |
| MODULE_LICENSE("GPL v2");
 | |
| MODULE_ALIAS("spi:el15203000");
 |