This patch adds a LED class driver for the RGB LEDs found on
the Crane Merchandising System CR0014114 LEDs board.
Signed-off-by: Oleh Kravchenko <oleg@xxxxxxxxxx>
---
.../devicetree/bindings/leds/leds-cr0014114.txt | 46 ++++
.../devicetree/bindings/vendor-prefixes.txt | 1 +
drivers/leds/Kconfig | 13 +
drivers/leds/Makefile | 1 +
drivers/leds/leds-cr0014114.c | 292 +++++++++++++++++++++
5 files changed, 353 insertions(+)
create mode 100644 Documentation/devicetree/bindings/leds/leds-cr0014114.txt
create mode 100644 drivers/leds/leds-cr0014114.c
diff --git a/Documentation/devicetree/bindings/leds/leds-cr0014114.txt b/Documentation/devicetree/bindings/leds/leds-cr0014114.txt
new file mode 100644
index 000000000000..977a9929b04f
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-cr0014114.txt
@@ -0,0 +1,46 @@
+Crane Merchandising System - cr0014114 LED driver
+-------------------------------------------------
+
+This LED Board is widely used in vending machines produced
+by Crane Merchandising Systems.
+
+Required properties:
+- compatible: "cms,cr0014114"
+- reg: chip select address for the device
+- spi-cpha: shifted clock phase mode is required
+
+LED sub-node properties:
+- label : (optional)
+ see Documentation/devicetree/bindings/leds/common.txt
+- linux,default-trigger : (optional)
+ see Documentation/devicetree/bindings/leds/common.txt
+
+Example
+-------
+
+cr0014114@0 {
+ compatible = "crane,cr0014114";
+ reg = <0>;
+ spi-max-frequency = <50000>;
+ spi-cpha;
+
+ led0 {
+ label = "cr0:red:";
+ };
+ led1 {
+ label = "cr0:green:";
+ };
+ led2 {
+ label = "cr0:blue:";
+ };
+ led3 {
+ label = "cr1:red:";
+ };
+ led4 {
+ label = "cr1:green:";
+ };
+ led5 {
+ label = "cr1:blue:";
+ };
+ ...
+};
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index ae850d6c0ad3..f17949c365f5 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -75,6 +75,7 @@ cnxt Conexant Systems, Inc.
compulab CompuLab Ltd.
cortina Cortina Systems, Inc.
cosmic Cosmic Circuits
+crane Crane Connectivity Solutions
creative Creative Technology Ltd
crystalfontz Crystalfontz America, Inc.
cubietech Cubietech, Ltd.
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 2c896c0e69e1..5831814d01d0 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -104,6 +104,19 @@ config LEDS_CPCAP
This option enables support for LEDs offered by Motorola's
CPCAP PMIC.
+config LEDS_CR0014114
+ tristate "LED Support for Crane CR0014114"
+ depends on LEDS_CLASS
+ depends on SPI
+ depends on OF
+ help
+ This option enables support for CR0014114 LED Board which
+ is widely used in vending machines produced by
+ Crane Merchandising Systems.
+
+ To compile this driver as a module, choose M here: the module
+ will be called leds-cr0014114.
+
config LEDS_LM3530
tristate "LCD Backlight driver for LM3530"
depends on LEDS_CLASS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 91eca81cae82..0176e7335994 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -78,6 +78,7 @@ obj-$(CONFIG_LEDS_MT6323) += leds-mt6323.o
obj-$(CONFIG_LEDS_LM3692X) += leds-lm3692x.o
# LED SPI Drivers
+obj-$(CONFIG_LEDS_CR0014114) += leds-cr0014114.o
obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o
# LED Userspace Drivers
diff --git a/drivers/leds/leds-cr0014114.c b/drivers/leds/leds-cr0014114.c
new file mode 100644
index 000000000000..ef536a67dceb
--- /dev/null
+++ b/drivers/leds/leds-cr0014114.c
@@ -0,0 +1,292 @@
+/*
+ * LEDs driver for Crane CR0014114
+ *
+ * Copyright (C) 2018 Oleh Kravchenko <oleg@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/delay.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/property.h>
+#include <linux/spi/spi.h>
+#include <linux/spinlock.h>
+#include <linux/timer.h>
+#include <linux/workqueue.h>
+
+/* CR0014114 SPI commands */
+#define CR_SET_BRIGHTNESS 0x80
+#define CR_INIT_REENUMERATE 0x81
+#define CR_NEXT_REENUMERATE 0x82
+
+/* CR0014114 default settings */
+#define CR_MAX_BRIGHTNESS GENMASK(6, 0)
+#define CR_FW_DELAY_MSEC 10
+#define CR_RECOUNT_DELAY (HZ * 3600)
+
+struct cr0014114_led {
+ const char *name;
+ struct cr0014114 *priv;
+ struct led_classdev ldev;
+ u8 brightness;
+};
+
+struct cr0014114 {
+ bool do_recount;
+ size_t count;
+ struct device *dev;
+ struct mutex lock;
+ struct spi_device *spi;
+ struct timer_list timer;
+ struct work_struct work;
+ unsigned long delay;
+ struct cr0014114_led leds[];
+};
+
+static void cr0014114_calc_crc(u8 *buf, const size_t len)
+{
+ size_t i;
+ u8 crc;
+
+ for (i = 1, crc = 1; i < len - 1; i++)
+ crc += buf[i];
+ crc |= BIT(7);
+
+ /* special case when CRC matches the SPI commands */
+ if (crc == CR_SET_BRIGHTNESS ||
+ crc == CR_INIT_REENUMERATE ||
+ crc == CR_NEXT_REENUMERATE)
+ crc = 0xfe;
+
+ buf[len - 1] = crc;
+}
+
+static int cr0014114_recount(struct cr0014114 *priv)
+{
+ int ret;
+ size_t i;
+ u8 cmd;
+
+ dev_dbg(priv->dev, "recount of LEDs is started\n");
+
+ do {
+ cmd = CR_INIT_REENUMERATE;
+ ret = spi_write(priv->spi, &cmd, sizeof(cmd));
+ if (ret)
+ break;
+
+ cmd = CR_NEXT_REENUMERATE;
+ for (i = 0; i < priv->count; i++) {
+ msleep(CR_FW_DELAY_MSEC);
+
+ ret = spi_write(priv->spi, &cmd, sizeof(cmd));
+ if (ret)
+ break;
+ }
+ } while (0);
+
+ dev_dbg(priv->dev, "recount of LEDs is complete, error: %d\n", ret);
+
+ return ret;
+}
+
+static int cr0014114_sync(struct cr0014114 *priv)
+{
+ int ret;
+ size_t i;
+ u8 data[priv->count + 2];
+ unsigned long udelay, now = jiffies;
+
+ /* to avoid SPI mistiming with firmware we should wait some time */
+ if (time_after(priv->delay, now)) {
+ udelay = jiffies_to_usecs(priv->delay - now);
+ usleep_range(udelay, udelay + 1);
+ }
+
+ do {
+ if (unlikely(priv->do_recount)) {
+ ret = cr0014114_recount(priv);
+ if (ret)
+ break;
+
+ priv->do_recount = false;
+ }
+
+ data[0] = CR_SET_BRIGHTNESS;
+ for (i = 0; i < priv->count; i++)
+ data[i + 1] = priv->leds[i].brightness;
+ cr0014114_calc_crc(data, sizeof(data));
+
+ ret = spi_write(priv->spi, data, sizeof(data));
+ if (ret)
+ break;
+ } while (0);
+
+ priv->delay = jiffies + msecs_to_jiffies(CR_FW_DELAY_MSEC);
+
+ return ret;
+}
+
+static void cr0014114_recount_work(struct work_struct *work)
+{
+ int ret;
+ struct cr0014114 *priv = container_of(work, struct cr0014114,
+ work);
+
+ mutex_lock(&priv->lock);
+ priv->do_recount = true;
+ ret = cr0014114_sync(priv);
+ mutex_unlock(&priv->lock);
+
+ if (ret)
+ dev_warn(priv->dev, "recount LEDs failed %d\n", ret);
+}
+
+static int cr0014114_set_sync(struct led_classdev *ldev,
+ enum led_brightness brightness)
+{
+ int ret;
+ struct cr0014114_led *led = container_of(ldev,
+ struct cr0014114_led,
+ ldev);
+
+ mutex_lock(&led->priv->lock);
+ led->brightness = (u8)brightness;
+ ret = cr0014114_sync(led->priv);
+ mutex_unlock(&led->priv->lock);
+
+ return ret;
+}
+
+static void cr0014114_recount_timer(struct timer_list *t)
+{
+ struct cr0014114 *priv = from_timer(priv, t, timer);
+
+ schedule_work(&priv->work);
+ mod_timer(&priv->timer, jiffies + CR_RECOUNT_DELAY);
+}
+
+static int cr0014114_probe_dt(struct cr0014114 *priv)
+{
+ size_t i = 0;
+ struct cr0014114_led *led;
+ struct fwnode_handle *child;
+ struct device_node *np;
+ int ret;
+
+ device_for_each_child_node(priv->dev, child) {
+ np = to_of_node(child);
+ led = &priv->leds[i];
+
+ ret = fwnode_property_read_string(child, "label",
+ &led->name);
+ if (ret && IS_ENABLED(CONFIG_OF) && np)
+ led->name = np->name;
+
+ if (!led->name) {
+ fwnode_handle_put(child);
+ return -EINVAL;
+ }
+
+ fwnode_property_read_string(child, "linux,default-trigger",
+ &led->ldev.default_trigger);
+
+ led->priv = priv;
+ led->ldev.name = led->name;
+ led->ldev.brightness = LED_OFF;
+ led->ldev.max_brightness = CR_MAX_BRIGHTNESS;
+ led->ldev.brightness_set_blocking = cr0014114_set_sync;
+
+ ret = devm_of_led_classdev_register(priv->dev, np,
+ &led->ldev);
+ if (ret) {
+ fwnode_handle_put(child);
+ return ret;
+ }
+
+ led->ldev.dev->of_node = np;
+
+ i++;
+ }
+
+ return 0;
+}
+
+static int cr0014114_probe(struct spi_device *spi)
+{
+ struct cr0014114 *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,
+ sizeof(*priv) + sizeof(*priv->leds) * count,
+ GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ mutex_init(&priv->lock);
+ INIT_WORK(&priv->work, cr0014114_recount_work);
+ priv->do_recount = true;
+ priv->count = count;
+ priv->dev = &spi->dev;
+ priv->spi = spi;
+
+ ret = cr0014114_probe_dt(priv);
+ if (ret)
+ return ret;
+
+ ret = cr0014114_sync(priv);
+ if (ret)
+ return ret;
+
+ /* setup recount timer to workaround buggy firmware */
+ timer_setup(&priv->timer, cr0014114_recount_timer, 0);
+ mod_timer(&priv->timer, jiffies + CR_RECOUNT_DELAY);
+
+ spi_set_drvdata(spi, priv);
+
+ return 0;
+}
+
+static int cr0014114_remove(struct spi_device *spi)
+{
+ struct cr0014114 *priv = spi_get_drvdata(spi);
+
+ cancel_work_sync(&priv->work);
+ del_timer_sync(&priv->timer);
+
+ return 0;
+}
+
+static const struct of_device_id cr0014114_dt_ids[] = {
+ { .compatible = "crane,cr0014114", },
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, cr0014114_dt_ids);
+
+static struct spi_driver cr0014114_driver = {
+ .probe = cr0014114_probe,
+ .remove = cr0014114_remove,
+ .driver = {
+ .name = KBUILD_MODNAME,
+ .of_match_table = cr0014114_dt_ids,
+ },
+};
+
+module_spi_driver(cr0014114_driver);
+
+MODULE_AUTHOR("Oleh Kravchenko <oleg@xxxxxxxxxx>");
+MODULE_DESCRIPTION("cr0014114 LED driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("spi:cr0014114");
--
2.13.6
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