v7 EL15203000

v7 EL15203000

[Oleh Kravchenko]

[PATCH v8 1/2] dt-bindings: Add docs for EL15203000
[PATCH v8 2/2] leds: add LED driver for EL15203000 board

Changes what was made:
- removed odd spaces;
- use only one return in el15203000_pattern_set_P();
- reduce returns in el15203000_probe_dt();
- remove ret variable from el15203000_probe().

[PATCH v8 1/2] dt-bindings: Add docs for EL15203000

[Oleh Kravchenko]

Add documentation and example for dt-bindings EL15203000.
LED board (aka RED LED board) from Crane Merchandising Systems.

Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>
---
 .../bindings/leds/leds-el15203000.txt         | 53 +++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/leds-el15203000.txt

diff --git a/Documentation/devicetree/bindings/leds/leds-el15203000.txt b/Documentation/devicetree/bindings/leds/leds-el15203000.txt
new file mode 100644
index 000000000000..d74b492d28b2
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-el15203000.txt
@@ -0,0 +1,53 @@
+Crane Merchandising System - el15203000 LED driver
+--------------------------------------------------
+
+This LED Board (aka RED LEDs board) is widely used in
+coffee vending machines produced by Crane Merchandising Systems.
+
+Required properties:
+- compatible : "crane,el15203000"
+
+Property rules described in
+Documentation/devicetree/bindings/spi/spi-controller.yaml is apply.
+In particular, "reg" and "spi-max-frequency" properties must be given.
+50KHz is very well tested value for spi-max-frequency.
+
+Optional LED sub-node properties:
+- function:
+	see Documentation/devicetree/bindings/leds/common.txt
+- color:
+	see Documentation/devicetree/bindings/leds/common.txt
+
+Example
+-------
+
+#include <dt-bindings/leds/common.h>
+
+led-controller@0 {
+	compatible = "crane,el15203000";
+	reg = <0>;
+	spi-max-frequency = <50000>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	/* water pipe */
+	led@50 {
+		reg = <0x50>;
+		function = "pipe";
+		color = <LED_COLOR_ID_RED>;
+	};
+
+	/* screen frame */
+	led@53 {
+		reg = <0x53>;
+		function = "screen";
+		color = <LED_COLOR_ID_RED>;
+	};
+
+	/* vending area */
+	led@56 {
+		reg = <0x56>;
+		function = "vend";
+		color = <LED_COLOR_ID_RED>;
+	};
+};
-- 
2.21.0

[PATCH v8 2/2] leds: add LED driver for EL15203000 board

[Oleh Kravchenko]

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: Oleh Kravchenko <oleg@kaa.org.ua>
---
 .../testing/sysfs-class-led-driver-el15203000 |  32 ++
 drivers/leds/Kconfig                          |  13 +
 drivers/leds/Makefile                         |   1 +
 drivers/leds/leds-el15203000.c                | 357 ++++++++++++++++++
 4 files changed, 403 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-class-led-driver-el15203000
 create mode 100644 drivers/leds/leds-el15203000.c

diff --git a/Documentation/ABI/testing/sysfs-class-led-driver-el15203000 b/Documentation/ABI/testing/sysfs-class-led-driver-el15203000
new file mode 100644
index 000000000000..5e9cbf49da59
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-led-driver-el15203000
@@ -0,0 +1,32 @@
+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"
+
+		Cascade mode for Pipe LED:
+		"1 800 2 800 4 800 8 800 16 800"
+
+		Inverted cascade mode for Pipe LED:
+		"30 800 29 800 27 800 23 800 15 800"
+
+		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"
+
+		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"
+
+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
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 1988de1d64c0..6e7703fd03d0 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -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
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 41fb073a39c1..2da39e896ce8 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -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
diff --git a/drivers/leds/leds-el15203000.c b/drivers/leds/leds-el15203000.c
new file mode 100644
index 000000000000..298b13e4807a
--- /dev/null
+++ b/drivers/leds/leds-el15203000.c
@@ -0,0 +1,357 @@
+// 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");
-- 
2.21.0

Re: v7 EL15203000

[Dan Murphy]

Oleh

On 9/12/19 5:11 PM, Oleh Kravchenko wrote:
> [PATCH v8 1/2] dt-bindings: Add docs for EL15203000
> [PATCH v8 2/2] leds: add LED driver for EL15203000 board

$subject of cover letter should be v8

Dan

> Changes what was made:
> - removed odd spaces;
> - use only one return in el15203000_pattern_set_P();
> - reduce returns in el15203000_probe_dt();
> - remove ret variable from el15203000_probe().
>

Re: [PATCH v8 1/2] dt-bindings: Add docs for EL15203000

[Dan Murphy]

Oleh

On 9/12/19 5:11 PM, Oleh Kravchenko wrote:
> Add documentation and example for dt-bindings EL15203000.
> LED board (aka RED LED board) from Crane Merchandising Systems.
>
> Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>
> ---
>   .../bindings/leds/leds-el15203000.txt         | 53 +++++++++++++++++++
>   1 file changed, 53 insertions(+)
>   create mode 100644 Documentation/devicetree/bindings/leds/leds-el15203000.txt
>
> diff --git a/Documentation/devicetree/bindings/leds/leds-el15203000.txt b/Documentation/devicetree/bindings/leds/leds-el15203000.txt
> new file mode 100644
> index 000000000000..d74b492d28b2
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/leds-el15203000.txt
> @@ -0,0 +1,53 @@
> +Crane Merchandising System - el15203000 LED driver
> +--------------------------------------------------
> +
> +This LED Board (aka RED LEDs board) is widely used in
> +coffee vending machines produced by Crane Merchandising Systems.
> +
> +Required properties:
> +- compatible : "crane,el15203000"
> +
> +Property rules described in
> +Documentation/devicetree/bindings/spi/spi-controller.yaml is apply.

Not sure what this statement means


> +In particular, "reg" and "spi-max-frequency" properties must be given.
> +50KHz is very well tested value for spi-max-frequency.
> +
> +Optional LED sub-node properties:
> +- function:
> +	see Documentation/devicetree/bindings/leds/common.txt

This was not fixed per v7 comments

Where is the "reg" property definition for the LED child node?

What is the 0x50,0x53 and 0x56 mean? Are there any other values?

Dan

<snip>

Re: [PATCH v8 2/2] leds: add LED driver for EL15203000 board

[Dan Murphy]

Oleh

On 9/12/19 5:11 PM, Oleh Kravchenko wrote:
> 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: Oleh Kravchenko <oleg@kaa.org.ua>

Reviewed-by: Dan Murphy <dmurphy@ti.com>

v7 EL15203000

[Oleh Kravchenko]

[PATCH v7 1/2] dt-bindings: Add docs for EL15203000
[PATCH v7 2/2] leds: add LED driver for EL15203000 board

Fixed compilation error missing variable led.
Compiled and checked on real device.