* [PATCH v8 2/2] leds: add LED driver for EL15203000 board
2019-09-12 22:11 v7 EL15203000 Oleh Kravchenko
2019-09-12 22:11 ` [PATCH v8 1/2] dt-bindings: Add docs for EL15203000 Oleh Kravchenko
@ 2019-09-12 22:11 ` Oleh Kravchenko
2019-09-13 13:42 ` Dan Murphy
2019-09-13 13:36 ` v7 EL15203000 Dan Murphy
2 siblings, 1 reply; 6+ messages in thread
From: Oleh Kravchenko @ 2019-09-12 22:11 UTC (permalink / raw)
To: devicetree, linux-leds, jacek.anaszewski, pavel; +Cc: 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
^ permalink raw reply related [flat|nested] 6+ messages in thread