summaryrefslogtreecommitdiffstats
path: root/drivers/leds/leds-el15203000.c
blob: f9eb59a2557054934bcc36786584b0383252ec48 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
// 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/mod_devicetable.h>
#include <linux/module.h>
#include <linux/property.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 led_classdev	ldev;
	struct el15203000	*priv;
	u32			reg;
};

struct el15203000 {
	struct device		*dev;
	struct mutex		lock;
	struct spi_device	*spi;
	unsigned long		delay;
	size_t			count;
	struct el15203000_led	leds[];
};

#define to_el15203000_led(d)	container_of(d, struct el15203000_led, ldev)

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 = to_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 = to_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)
{
	struct el15203000_led	*led = to_el15203000_led(ldev);
	u8			cmd;

	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 = to_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");
			goto err_child_out;
		}

		if (led->reg > U8_MAX) {
			dev_err(priv->dev, "LED value %d is invalid", led->reg);
			ret = -EINVAL;
			goto err_child_out;
		}

		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);
			goto err_child_out;
		}

		led++;
	}

	return 0;

err_child_out:
	fwnode_handle_put(child);
	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");