1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2019 Crane Merchandising Systems. All rights reserved.
3 // Copyright (C) 2019 Oleh Kravchenko <oleg@kaa.org.ua>
5 #include <linux/delay.h>
6 #include <linux/leds.h>
7 #include <linux/module.h>
8 #include <linux/of_device.h>
9 #include <linux/spi/spi.h>
12 * EL15203000 SPI protocol description:
18 * (*) LEDs MCU board expects 20 msec delay per byte.
21 * +----------+--------------+-------------------------------------------+
22 * | ID | NAME | DESCRIPTION |
23 * +----------+--------------+-------------------------------------------+
24 * | 'P' 0x50 | Pipe | Consists from 5 LEDs, controlled by board |
25 * +----------+--------------+-------------------------------------------+
26 * | 'S' 0x53 | Screen frame | Light tube around the screen |
27 * +----------+--------------+-------------------------------------------+
28 * | 'V' 0x56 | Vending area | Highlights a cup of coffee |
29 * +----------+--------------+-------------------------------------------+
32 * +----------+-----------------+--------------+--------------+
33 * | VALUES | PIPE | SCREEN FRAME | VENDING AREA |
34 * +----------+-----------------+--------------+--------------+
36 * +----------+-----------------------------------------------+
38 * +----------+-----------------+--------------+--------------+
39 * | '2' 0x32 | Cascade | Breathing |
40 * +----------+-----------------+--------------+
41 * | '3' 0x33 | Inverse cascade |
42 * +----------+-----------------+
43 * | '4' 0x34 | Bounce |
44 * +----------+-----------------+
45 * | '5' 0x35 | Inverse bounce |
46 * +----------+-----------------+
49 /* EL15203000 default settings */
50 #define EL_FW_DELAY_USEC 20000ul
51 #define EL_PATTERN_DELAY_MSEC 800u
52 #define EL_PATTERN_LEN 10u
53 #define EL_PATTERN_HALF_LEN (EL_PATTERN_LEN / 2)
55 enum el15203000_command {
61 EL_SCREEN_BREATHING = '2',
64 EL_PIPE_CASCADE = '2',
65 EL_PIPE_INV_CASCADE = '3',
67 EL_PIPE_INV_BOUNCE = '5',
70 struct el15203000_led {
71 struct led_classdev ldev;
72 struct el15203000 *priv;
79 struct spi_device *spi;
82 struct el15203000_led leds[];
85 #define to_el15203000_led(d) container_of(d, struct el15203000_led, ldev)
87 static int el15203000_cmd(struct el15203000_led *led, u8 brightness)
93 mutex_lock(&led->priv->lock);
95 dev_dbg(led->priv->dev, "Set brightness of 0x%02x(%c) to 0x%02x(%c)",
96 led->reg, led->reg, brightness, brightness);
98 /* to avoid SPI mistiming with firmware we should wait some time */
99 if (time_after(led->priv->delay, jiffies)) {
100 dev_dbg(led->priv->dev, "Wait %luus to sync",
103 usleep_range(EL_FW_DELAY_USEC,
104 EL_FW_DELAY_USEC + 1);
110 for (i = 0; i < ARRAY_SIZE(cmd); i++) {
112 usleep_range(EL_FW_DELAY_USEC,
113 EL_FW_DELAY_USEC + 1);
115 ret = spi_write(led->priv->spi, &cmd[i], sizeof(cmd[i]));
117 dev_err(led->priv->dev,
118 "spi_write() error %d", ret);
123 led->priv->delay = jiffies + usecs_to_jiffies(EL_FW_DELAY_USEC);
125 mutex_unlock(&led->priv->lock);
130 static int el15203000_set_blocking(struct led_classdev *ldev,
131 enum led_brightness brightness)
133 struct el15203000_led *led = to_el15203000_led(ldev);
135 return el15203000_cmd(led, brightness == LED_OFF ? EL_OFF : EL_ON);
138 static int el15203000_pattern_set_S(struct led_classdev *ldev,
139 struct led_pattern *pattern,
142 struct el15203000_led *led = to_el15203000_led(ldev);
144 if (repeat > 0 || len != 2 ||
145 pattern[0].delta_t != 4000 || pattern[0].brightness != 0 ||
146 pattern[1].delta_t != 4000 || pattern[1].brightness != 1)
149 dev_dbg(led->priv->dev, "Breathing mode for 0x%02x(%c)",
152 return el15203000_cmd(led, EL_SCREEN_BREATHING);
155 static bool is_cascade(const struct led_pattern *pattern, u32 len,
156 bool inv, bool right)
161 if (len != EL_PATTERN_HALF_LEN)
164 val = right ? BIT(4) : BIT(0);
166 for (i = 0; i < len; i++) {
167 t = inv ? ~val & GENMASK(4, 0) : val;
169 if (pattern[i].delta_t != EL_PATTERN_DELAY_MSEC ||
170 pattern[i].brightness != t)
173 val = right ? val >> 1 : val << 1;
179 static bool is_bounce(const struct led_pattern *pattern, u32 len, bool inv)
181 if (len != EL_PATTERN_LEN)
184 return is_cascade(pattern, EL_PATTERN_HALF_LEN, inv, false) &&
185 is_cascade(pattern + EL_PATTERN_HALF_LEN,
186 EL_PATTERN_HALF_LEN, inv, true);
189 static int el15203000_pattern_set_P(struct led_classdev *ldev,
190 struct led_pattern *pattern,
193 struct el15203000_led *led = to_el15203000_led(ldev);
199 if (is_cascade(pattern, len, false, false)) {
200 dev_dbg(led->priv->dev, "Cascade mode for 0x%02x(%c)",
203 cmd = EL_PIPE_CASCADE;
204 } else if (is_cascade(pattern, len, true, false)) {
205 dev_dbg(led->priv->dev, "Inverse cascade mode for 0x%02x(%c)",
208 cmd = EL_PIPE_INV_CASCADE;
209 } else if (is_bounce(pattern, len, false)) {
210 dev_dbg(led->priv->dev, "Bounce mode for 0x%02x(%c)",
213 cmd = EL_PIPE_BOUNCE;
214 } else if (is_bounce(pattern, len, true)) {
215 dev_dbg(led->priv->dev, "Inverse bounce mode for 0x%02x(%c)",
218 cmd = EL_PIPE_INV_BOUNCE;
220 dev_err(led->priv->dev, "Invalid hw_pattern for 0x%02x(%c)!",
226 return el15203000_cmd(led, cmd);
229 static int el15203000_pattern_clear(struct led_classdev *ldev)
231 struct el15203000_led *led = to_el15203000_led(ldev);
233 return el15203000_cmd(led, EL_OFF);
236 static int el15203000_probe_dt(struct el15203000 *priv)
238 struct el15203000_led *led = priv->leds;
239 struct fwnode_handle *child;
242 device_for_each_child_node(priv->dev, child) {
243 struct led_init_data init_data = {};
245 ret = fwnode_property_read_u32(child, "reg", &led->reg);
247 dev_err(priv->dev, "LED without ID number");
251 if (led->reg > U8_MAX) {
252 dev_err(priv->dev, "LED value %d is invalid", led->reg);
258 led->ldev.max_brightness = LED_ON;
259 led->ldev.brightness_set_blocking = el15203000_set_blocking;
261 if (led->reg == 'S') {
262 led->ldev.pattern_set = el15203000_pattern_set_S;
263 led->ldev.pattern_clear = el15203000_pattern_clear;
264 } else if (led->reg == 'P') {
265 led->ldev.pattern_set = el15203000_pattern_set_P;
266 led->ldev.pattern_clear = el15203000_pattern_clear;
269 init_data.fwnode = child;
270 ret = devm_led_classdev_register_ext(priv->dev, &led->ldev,
274 "failed to register LED device %s, err %d",
275 led->ldev.name, ret);
285 fwnode_handle_put(child);
289 static int el15203000_probe(struct spi_device *spi)
291 struct el15203000 *priv;
294 count = device_get_child_node_count(&spi->dev);
296 dev_err(&spi->dev, "LEDs are not defined in device tree!");
300 priv = devm_kzalloc(&spi->dev, struct_size(priv, leds, count),
305 mutex_init(&priv->lock);
307 priv->dev = &spi->dev;
309 priv->delay = jiffies -
310 usecs_to_jiffies(EL_FW_DELAY_USEC);
312 spi_set_drvdata(spi, priv);
314 return el15203000_probe_dt(priv);
317 static int el15203000_remove(struct spi_device *spi)
319 struct el15203000 *priv = spi_get_drvdata(spi);
321 mutex_destroy(&priv->lock);
326 static const struct of_device_id el15203000_dt_ids[] = {
327 { .compatible = "crane,el15203000", },
331 MODULE_DEVICE_TABLE(of, el15203000_dt_ids);
333 static struct spi_driver el15203000_driver = {
334 .probe = el15203000_probe,
335 .remove = el15203000_remove,
337 .name = KBUILD_MODNAME,
338 .of_match_table = el15203000_dt_ids,
342 module_spi_driver(el15203000_driver);
344 MODULE_AUTHOR("Oleh Kravchenko <oleg@kaa.org.ua>");
345 MODULE_DESCRIPTION("el15203000 LED driver");
346 MODULE_LICENSE("GPL v2");
347 MODULE_ALIAS("spi:el15203000");