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>
4
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>
10
11 /*
12 * EL15203000 SPI protocol description:
13 * +-----+---------+
14 * | LED | COMMAND |
15 * +-----+---------+
16 * | 1 | 1 |
17 * +-----+---------+
18 * (*) LEDs MCU board expects 20 msec delay per byte.
19 *
20 * LEDs:
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 * +----------+--------------+-------------------------------------------+
30 *
31 * COMMAND:
32 * +----------+-----------------+--------------+--------------+
33 * | VALUES | PIPE | SCREEN FRAME | VENDING AREA |
34 * +----------+-----------------+--------------+--------------+
35 * | '0' 0x30 | Off |
36 * +----------+-----------------------------------------------+
37 * | '1' 0x31 | On |
38 * +----------+-----------------+--------------+--------------+
39 * | '2' 0x32 | Cascade | Breathing |
40 * +----------+-----------------+--------------+
41 * | '3' 0x33 | Inverse cascade |
42 * +----------+-----------------+
43 * | '4' 0x34 | Bounce |
44 * +----------+-----------------+
45 * | '5' 0x35 | Inverse bounce |
46 * +----------+-----------------+
47 */
48
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)
54
55 enum el15203000_command {
56 /* for all LEDs */
57 EL_OFF = '0',
58 EL_ON = '1',
59
60 /* for Screen LED */
61 EL_SCREEN_BREATHING = '2',
62
63 /* for Pipe LED */
64 EL_PIPE_CASCADE = '2',
65 EL_PIPE_INV_CASCADE = '3',
66 EL_PIPE_BOUNCE = '4',
67 EL_PIPE_INV_BOUNCE = '5',
68 };
69
70 struct el15203000_led {
71 struct el15203000 *priv;
72 struct led_classdev ldev;
73 u32 reg;
74 };
75
76 struct el15203000 {
77 struct device *dev;
78 struct mutex lock;
79 struct spi_device *spi;
80 unsigned long delay;
81 size_t count;
82 struct el15203000_led leds[];
83 };
84
el15203000_cmd(struct el15203000_led * led,u8 brightness)85 static int el15203000_cmd(struct el15203000_led *led, u8 brightness)
86 {
87 int ret;
88 u8 cmd[2];
89 size_t i;
90
91 mutex_lock(&led->priv->lock);
92
93 dev_dbg(led->priv->dev, "Set brightness of 0x%02x(%c) to 0x%02x(%c)",
94 led->reg, led->reg, brightness, brightness);
95
96 /* to avoid SPI mistiming with firmware we should wait some time */
97 if (time_after(led->priv->delay, jiffies)) {
98 dev_dbg(led->priv->dev, "Wait %luus to sync",
99 EL_FW_DELAY_USEC);
100
101 usleep_range(EL_FW_DELAY_USEC,
102 EL_FW_DELAY_USEC + 1);
103 }
104
105 cmd[0] = led->reg;
106 cmd[1] = brightness;
107
108 for (i = 0; i < ARRAY_SIZE(cmd); i++) {
109 if (i)
110 usleep_range(EL_FW_DELAY_USEC,
111 EL_FW_DELAY_USEC + 1);
112
113 ret = spi_write(led->priv->spi, &cmd[i], sizeof(cmd[i]));
114 if (ret) {
115 dev_err(led->priv->dev,
116 "spi_write() error %d", ret);
117 break;
118 }
119 }
120
121 led->priv->delay = jiffies + usecs_to_jiffies(EL_FW_DELAY_USEC);
122
123 mutex_unlock(&led->priv->lock);
124
125 return ret;
126 }
127
el15203000_set_blocking(struct led_classdev * ldev,enum led_brightness brightness)128 static int el15203000_set_blocking(struct led_classdev *ldev,
129 enum led_brightness brightness)
130 {
131 struct el15203000_led *led = container_of(ldev,
132 struct el15203000_led,
133 ldev);
134
135 return el15203000_cmd(led, brightness == LED_OFF ? EL_OFF : EL_ON);
136 }
137
el15203000_pattern_set_S(struct led_classdev * ldev,struct led_pattern * pattern,u32 len,int repeat)138 static int el15203000_pattern_set_S(struct led_classdev *ldev,
139 struct led_pattern *pattern,
140 u32 len, int repeat)
141 {
142 struct el15203000_led *led = container_of(ldev,
143 struct el15203000_led,
144 ldev);
145
146 if (repeat > 0 || len != 2 ||
147 pattern[0].delta_t != 4000 || pattern[0].brightness != 0 ||
148 pattern[1].delta_t != 4000 || pattern[1].brightness != 1)
149 return -EINVAL;
150
151 dev_dbg(led->priv->dev, "Breathing mode for 0x%02x(%c)",
152 led->reg, led->reg);
153
154 return el15203000_cmd(led, EL_SCREEN_BREATHING);
155 }
156
is_cascade(const struct led_pattern * pattern,u32 len,bool inv,bool right)157 static bool is_cascade(const struct led_pattern *pattern, u32 len,
158 bool inv, bool right)
159 {
160 int val, t;
161 u32 i;
162
163 if (len != EL_PATTERN_HALF_LEN)
164 return false;
165
166 val = right ? BIT(4) : BIT(0);
167
168 for (i = 0; i < len; i++) {
169 t = inv ? ~val & GENMASK(4, 0) : val;
170
171 if (pattern[i].delta_t != EL_PATTERN_DELAY_MSEC ||
172 pattern[i].brightness != t)
173 return false;
174
175 val = right ? val >> 1 : val << 1;
176 }
177
178 return true;
179 }
180
is_bounce(const struct led_pattern * pattern,u32 len,bool inv)181 static bool is_bounce(const struct led_pattern *pattern, u32 len, bool inv)
182 {
183 if (len != EL_PATTERN_LEN)
184 return false;
185
186 return is_cascade(pattern, EL_PATTERN_HALF_LEN, inv, false) &&
187 is_cascade(pattern + EL_PATTERN_HALF_LEN,
188 EL_PATTERN_HALF_LEN, inv, true);
189 }
190
el15203000_pattern_set_P(struct led_classdev * ldev,struct led_pattern * pattern,u32 len,int repeat)191 static int el15203000_pattern_set_P(struct led_classdev *ldev,
192 struct led_pattern *pattern,
193 u32 len, int repeat)
194 {
195 u8 cmd;
196 struct el15203000_led *led = container_of(ldev,
197 struct el15203000_led,
198 ldev);
199
200 if (repeat > 0)
201 return -EINVAL;
202
203 if (is_cascade(pattern, len, false, false)) {
204 dev_dbg(led->priv->dev, "Cascade mode for 0x%02x(%c)",
205 led->reg, led->reg);
206
207 cmd = EL_PIPE_CASCADE;
208 } else if (is_cascade(pattern, len, true, false)) {
209 dev_dbg(led->priv->dev, "Inverse cascade mode for 0x%02x(%c)",
210 led->reg, led->reg);
211
212 cmd = EL_PIPE_INV_CASCADE;
213 } else if (is_bounce(pattern, len, false)) {
214 dev_dbg(led->priv->dev, "Bounce mode for 0x%02x(%c)",
215 led->reg, led->reg);
216
217 cmd = EL_PIPE_BOUNCE;
218 } else if (is_bounce(pattern, len, true)) {
219 dev_dbg(led->priv->dev, "Inverse bounce mode for 0x%02x(%c)",
220 led->reg, led->reg);
221
222 cmd = EL_PIPE_INV_BOUNCE;
223 } else {
224 dev_err(led->priv->dev, "Invalid hw_pattern for 0x%02x(%c)!",
225 led->reg, led->reg);
226
227 return -EINVAL;
228 }
229
230 return el15203000_cmd(led, cmd);
231 }
232
el15203000_pattern_clear(struct led_classdev * ldev)233 static int el15203000_pattern_clear(struct led_classdev *ldev)
234 {
235 struct el15203000_led *led = container_of(ldev,
236 struct el15203000_led,
237 ldev);
238
239 return el15203000_cmd(led, EL_OFF);
240 }
241
el15203000_probe_dt(struct el15203000 * priv)242 static int el15203000_probe_dt(struct el15203000 *priv)
243 {
244 struct el15203000_led *led = priv->leds;
245 struct fwnode_handle *child;
246 int ret;
247
248 device_for_each_child_node(priv->dev, child) {
249 struct led_init_data init_data = {};
250
251 ret = fwnode_property_read_u32(child, "reg", &led->reg);
252 if (ret) {
253 dev_err(priv->dev, "LED without ID number");
254 fwnode_handle_put(child);
255
256 break;
257 }
258
259 if (led->reg > U8_MAX) {
260 dev_err(priv->dev, "LED value %d is invalid", led->reg);
261 fwnode_handle_put(child);
262
263 return -EINVAL;
264 }
265
266 led->priv = priv;
267 led->ldev.max_brightness = LED_ON;
268 led->ldev.brightness_set_blocking = el15203000_set_blocking;
269
270 if (led->reg == 'S') {
271 led->ldev.pattern_set = el15203000_pattern_set_S;
272 led->ldev.pattern_clear = el15203000_pattern_clear;
273 } else if (led->reg == 'P') {
274 led->ldev.pattern_set = el15203000_pattern_set_P;
275 led->ldev.pattern_clear = el15203000_pattern_clear;
276 }
277
278 init_data.fwnode = child;
279 ret = devm_led_classdev_register_ext(priv->dev, &led->ldev,
280 &init_data);
281 if (ret) {
282 dev_err(priv->dev,
283 "failed to register LED device %s, err %d",
284 led->ldev.name, ret);
285 fwnode_handle_put(child);
286
287 break;
288 }
289
290 led++;
291 }
292
293 return ret;
294 }
295
el15203000_probe(struct spi_device * spi)296 static int el15203000_probe(struct spi_device *spi)
297 {
298 struct el15203000 *priv;
299 size_t count;
300
301 count = device_get_child_node_count(&spi->dev);
302 if (!count) {
303 dev_err(&spi->dev, "LEDs are not defined in device tree!");
304 return -ENODEV;
305 }
306
307 priv = devm_kzalloc(&spi->dev, struct_size(priv, leds, count),
308 GFP_KERNEL);
309 if (!priv)
310 return -ENOMEM;
311
312 mutex_init(&priv->lock);
313 priv->count = count;
314 priv->dev = &spi->dev;
315 priv->spi = spi;
316 priv->delay = jiffies -
317 usecs_to_jiffies(EL_FW_DELAY_USEC);
318
319 spi_set_drvdata(spi, priv);
320
321 return el15203000_probe_dt(priv);
322 }
323
el15203000_remove(struct spi_device * spi)324 static int el15203000_remove(struct spi_device *spi)
325 {
326 struct el15203000 *priv = spi_get_drvdata(spi);
327
328 mutex_destroy(&priv->lock);
329
330 return 0;
331 }
332
333 static const struct of_device_id el15203000_dt_ids[] = {
334 { .compatible = "crane,el15203000", },
335 {},
336 };
337
338 MODULE_DEVICE_TABLE(of, el15203000_dt_ids);
339
340 static struct spi_driver el15203000_driver = {
341 .probe = el15203000_probe,
342 .remove = el15203000_remove,
343 .driver = {
344 .name = KBUILD_MODNAME,
345 .of_match_table = el15203000_dt_ids,
346 },
347 };
348
349 module_spi_driver(el15203000_driver);
350
351 MODULE_AUTHOR("Oleh Kravchenko <oleg@kaa.org.ua>");
352 MODULE_DESCRIPTION("el15203000 LED driver");
353 MODULE_LICENSE("GPL v2");
354 MODULE_ALIAS("spi:el15203000");
355