This patch adds a LED class driver for the RGB LEDs found on
the Crane Merchandising System EL15203000 LEDs board
(aka RED LEDs board).
Signed-off-by: Oleh Kravchenko <oleg@xxxxxxxxxx>
---
drivers/leds/Kconfig | 13 ++
drivers/leds/Makefile | 1 +
drivers/leds/leds-el15203000.c | 230 +++++++++++++++++++++++++++++++++
3 files changed, 244 insertions(+)
create mode 100644 drivers/leds/leds-el15203000.c
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 71be87bdb926..ae293a0f7598 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -128,6 +128,19 @@ 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 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 1e9702ebffee..1f193ffc2feb 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -85,6 +85,7 @@ obj-$(CONFIG_LEDS_LM3601X) += leds-lm3601x.o
# LED SPI Drivers
obj-$(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..5598c3bc835d
--- /dev/null
+++ b/drivers/leds/leds-el15203000.c
@@ -0,0 +1,230 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2019 Crane Merchandising Systems. All rights reserved.
+// Copyright (C) 2019 Oleh Kravchenko <oleg@xxxxxxxxxx>
+
+#include <linux/delay.h>
+#include <linux/leds.h>
+#include <linux/limits.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/spi/spi.h>
+#include <uapi/linux/uleds.h>
+
+/*
+ * EL15203000 SPI protocol descrtiption:
+ * +-----+------------+
+ * | LED | BRIGHTNESS |
+ * +-----+------------+
+ * | 1 | 1 |
+ * +-----+------------+
+ *
+ * LED ID, known values is 0x50 (Pipe), 0x53 (Screen Frame) and
+ * 0x56 (Vending Area);
+ * BRIGHTNESS Can be 0x30 (OFF), 0x31 (ON).
+ * 0x32 (Effect) can be used for 0x50 (leaking) and
+ * for 0x53 (blinking).
+ *
+ * LEDs MCU board expects 20 msec delay per byte.
+ */
+
+/* EL15203000 default settings */
+#define EL_MAX_BRIGHTNESS 2
+#define EL_FW_DELAY_USEC 20000
+
+struct el15203000_led {
+ char name[LED_MAX_NAME_SIZE];
+ struct el15203000 *priv;
+ struct led_classdev ldev;
+ u8 reg;
+};
+
+struct el15203000 {
+ size_t count;
+ struct device *dev;
+ struct mutex lock;
+ struct spi_device *spi;
+ unsigned long delay;
+ struct el15203000_led leds[];
+};
+
+static int el15203000_set_sync(struct led_classdev *ldev,
+ enum led_brightness brightness)
+{
+ int ret;
+ u8 cmd[2];
+ size_t i;
+ unsigned long udelay, now;
+ struct el15203000_led *led = container_of(ldev,
+ struct el15203000_led,
+ ldev);
+
+ mutex_lock(&led->priv->lock);
+
+ dev_dbg(led->priv->dev, "Set brightness of %s to %d",
+ led->name, brightness);
+
+ /* to avoid SPI mistiming with firmware we should wait some time */
+ now = jiffies;
+ if (time_after(led->priv->delay, now)) {
+ udelay = jiffies_to_usecs(led->priv->delay - now);
+
+ dev_dbg(led->priv->dev, "Wait %luus to synch", udelay);
+ usleep_range(udelay, udelay + 1);
+ }
+
+ cmd[0] = led->reg;
+ cmd[1] = 0x30 + (u8)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\n", ret);
+ break;
+ }
+ }
+
+ led->priv->delay = jiffies + usecs_to_jiffies(EL_FW_DELAY_USEC);
+
+ mutex_unlock(&led->priv->lock);
+
+ return ret;
+}
+
+static int el15203000_probe_dt(struct el15203000 *priv)
+{
+ size_t i = 0;
+ struct el15203000_led *led;
+ struct fwnode_handle *child;
+ int ret;
+ const char *str;
+ u32 reg;
+
+ device_for_each_child_node(priv->dev, child) {
+ led = &priv->leds[i];
+
+ ret = fwnode_property_read_u32(child, "reg", ®);
+ if (ret) {
+ dev_err(priv->dev, "LED without ID number");
+ fwnode_handle_put(child);
+
+ return ret;
+ }
+ if (reg > U8_MAX) {
+ dev_err(priv->dev, "LED value %d is invalid", reg);
+ fwnode_handle_put(child);
+
+ return -EINVAL;
+ }
+ led->reg = reg;
+
+ ret = fwnode_property_read_string(child, "label", &str);
+ if (ret)
+ snprintf(led->name, sizeof(led->name),
+ "el15203000::");
+ else
+ snprintf(led->name, sizeof(led->name),
+ "el15203000:%s", str);
+
+ fwnode_property_read_string(child, "linux,default-trigger",
+ &led->ldev.default_trigger);
+
+ led->priv = priv;
+ led->ldev.name = led->name;
+ led->ldev.max_brightness = LED_ON;
+ led->ldev.brightness_set_blocking = el15203000_set_sync;
+
+ ret = fwnode_property_read_u32(child, "max-brightness",
+ &led->ldev.max_brightness);
+ if (led->ldev.max_brightness > EL_MAX_BRIGHTNESS) {
+ dev_err(priv->dev, "invalid max brightness %d",
+ led->ldev.max_brightness);
+ fwnode_handle_put(child);
+
+ return -EINVAL;
+ }
+
+ ret = devm_led_classdev_register(priv->dev, &led->ldev);
+ if (ret) {
+ dev_err(priv->dev,
+ "failed to register LED device %s, err %d",
+ led->name, ret);
+ fwnode_handle_put(child);
+ return ret;
+ }
+
+ i++;
+ }
+
+ return ret;
+}
+
+static int el15203000_probe(struct spi_device *spi)
+{
+ struct el15203000 *priv;
+ size_t count;
+ int ret;
+
+ 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);
+
+ ret = el15203000_probe_dt(priv);
+ if (ret)
+ return ret;
+
+ spi_set_drvdata(spi, priv);
+ dev_dbg(priv->dev, "%zd LEDs registered", priv->count);
+
+ return 0;
+}
+
+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@xxxxxxxxxx>");
+MODULE_DESCRIPTION("el15203000 LED driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("spi:el15203000");
--
2.21.0
