--- /dev/null
+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
--- /dev/null
+// 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");
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