Commit fc19967b authored by Oleh Kravchenko's avatar Oleh Kravchenko Committed by Pavel
Browse files

leds: add LED driver for EL15203000 board 



This patch adds a LED class driver for the LEDs found on
the Crane Merchandising System EL15203000 LEDs board
(aka RED LEDs board).

Signed-off-by: default avatarOleh Kravchenko <oleg@kaa.org.ua>
Reviewed-by: default avatarDan Murphy <dmurphy@ti.com>
Signed-off-by: default avatarPavel Machek <pavel@ucw.cz>
parent a788f6f2

Documentation/ABI/testing/sysfs-class-led-driver-el15203000

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Original line number Diff line number Diff line 
What:		/sys/class/leds/<led>/hw_pattern

Date:		September 2019

KernelVersion:	5.5

Description:

		Specify a hardware pattern for the EL15203000 LED.

		The LEDs board supports only predefined patterns by firmware

		for specific LEDs.



		Breathing mode for Screen frame light tube:

		"0 4000 1 4000"



		    ^

		    |

		Max-|     ---

		    |    /   \

		    |   /     \

		    |  /       \     /

		    | /         \   /

		Min-|-           ---

		    |

		    0------4------8--> time (sec)



		Cascade mode for Pipe LED:

		"1 800 2 800 4 800 8 800 16 800"



		      ^

		      |

		0 On -|----+                   +----+                   +---

		      |    |                   |    |                   |

		  Off-|    +-------------------+    +-------------------+

		      |

		1 On -|    +----+                   +----+

		      |    |    |                   |    |

		  Off |----+    +-------------------+    +------------------

		      |

		2 On -|         +----+                   +----+

		      |         |    |                   |    |

		  Off-|---------+    +-------------------+    +-------------

		      |

		3 On -|              +----+                   +----+

		      |              |    |                   |    |

		  Off-|--------------+    +-------------------+    +--------

		      |

		4 On -|                   +----+                   +----+

		      |                   |    |                   |    |

		  Off-|-------------------+    +-------------------+    +---

		      |

		      0---0.8--1.6--2.4--3.2---4---4.8--5.6--6.4--7.2---8--> time (sec)



		Inverted cascade mode for Pipe LED:

		"30 800 29 800 27 800 23 800 15 800"



		      ^

		      |

		0 On -|    +-------------------+    +-------------------+

		      |    |                   |    |                   |

		  Off-|----+                   +----+                   +---

		      |

		1 On -|----+    +-------------------+    +------------------

		      |    |    |                   |    |

		  Off |    +----+                   +----+

		      |

		2 On -|---------+    +-------------------+    +-------------

		      |         |    |                   |    |

		  Off-|         +----+                   +----+

		      |

		3 On -|--------------+    +-------------------+    +--------

		      |              |    |                   |    |

		  Off-|              +----+                   +----+

		      |

		4 On -|-------------------+    +-------------------+    +---

		      |                   |    |                   |    |

		  Off-|                   +----+                   +----+

		      |

		      0---0.8--1.6--2.4--3.2---4---4.8--5.6--6.4--7.2---8--> time (sec)



		Bounce mode for Pipe LED:

		"1 800 2 800 4 800 8 800 16 800 16 800 8 800 4 800 2 800 1 800"



		      ^

		      |

		0 On -|----+                                       +--------

		      |    |                                       |

		  Off-|    +---------------------------------------+

		      |

		1 On -|    +----+                             +----+

		      |    |    |                             |    |

		  Off |----+    +-----------------------------+    +--------

		      |

		2 On -|         +----+                   +----+

		      |         |    |                   |    |

		  Off-|---------+    +-------------------+    +-------------

		      |

		3 On -|              +----+         +----+

		      |              |    |         |    |

		  Off-|--------------+    +---------+    +------------------

		      |

		4 On -|                   +---------+

		      |                   |         |

		  Off-|-------------------+         +-----------------------

		      |

		      0---0.8--1.6--2.4--3.2---4---4.8--5.6--6.4--7.2---8--> time (sec)



		Inverted bounce mode for Pipe LED:

		"30 800 29 800 27 800 23 800 15 800 15 800 23 800 27 800 29 800 30 800"



		      ^

		      |

		0 On -|    +---------------------------------------+

		      |    |                                       |

		  Off-|----+                                       +--------

		      |

		1 On -|----+    +-----------------------------+    +--------

		      |    |    |                             |    |

		  Off |    +----+                             +----+

		      |

		2 On -|---------+    +-------------------+    +-------------

		      |         |    |                   |    |

		  Off-|         +----+                   +----+

		      |

		3 On -|--------------+    +---------+    +------------------

		      |              |    |         |    |

		  Off-|              +----+         +----+

		      |

		4 On -|-------------------+         +-----------------------

		      |                   |         |

		  Off-|                   +---------+

		      |

		      0---0.8--1.6--2.4--3.2---4---4.8--5.6--6.4--7.2---8--> time (sec)



What:		/sys/class/leds/<led>/repeat

Date:		September 2019

KernelVersion:	5.5

Description:

		EL15203000 supports only indefinitely patterns,

		so this file should always store -1.



		For more info, please see:

		Documentation/ABI/testing/sysfs-class-led-trigger-pattern

drivers/leds/Kconfig

+13 −0
Original line number Diff line number Diff line
@@ -132,6 +132,19 @@ config LEDS_CR0014114 
	  To compile this driver as a module, choose M here: the module

	  will be called leds-cr0014114.



config LEDS_EL15203000

	tristate "LED Support for Crane EL15203000"

	depends on LEDS_CLASS

	depends on SPI

	depends on OF

	help

	  This option enables support for EL15203000 LED Board

	  (aka RED LED board) which is widely used in coffee vending

	  machines produced by Crane Merchandising Systems.



	  To compile this driver as a module, choose M here: the module

	  will be called leds-el15203000.



config LEDS_LM3530

	tristate "LCD Backlight driver for LM3530"

	depends on LEDS_CLASS

drivers/leds/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -89,6 +89,7 @@ obj-$(CONFIG_LEDS_LM36274) += leds-lm36274.o 
# LED SPI Drivers

obj-$(CONFIG_LEDS_CR0014114)		+= leds-cr0014114.o

obj-$(CONFIG_LEDS_DAC124S085)		+= leds-dac124s085.o

obj-$(CONFIG_LEDS_EL15203000)		+= leds-el15203000.o



# LED Userspace Drivers

obj-$(CONFIG_LEDS_USER)			+= uleds.o

drivers/leds/leds-el15203000.c

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// 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 el15203000	*priv;

	struct led_classdev	ldev;

	u32			reg;

};



struct el15203000 {

	struct device		*dev;

	struct mutex		lock;

	struct spi_device	*spi;

	unsigned long		delay;

	size_t			count;

	struct el15203000_led	leds[];

};



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 = container_of(ldev,

						  struct 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 = container_of(ldev,

						  struct 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)

{

	u8			cmd;

	struct el15203000_led	*led = container_of(ldev,

						    struct el15203000_led,

						    ldev);



	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 = container_of(ldev,

						    struct 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");

			fwnode_handle_put(child);



			break;

		}



		if (led->reg > U8_MAX) {

			dev_err(priv->dev, "LED value %d is invalid", led->reg);

			fwnode_handle_put(child);



			return -EINVAL;

		}



		fwnode_property_read_string(child, "linux,default-trigger",

					    &led->ldev.default_trigger);



		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);

			fwnode_handle_put(child);



			break;

		}



		led++;

	}



	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");