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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>
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49
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
55enum el15203000_command {
56
57 EL_OFF = '0',
58 EL_ON = '1',
59
60
61 EL_SCREEN_BREATHING = '2',
62
63
64 EL_PIPE_CASCADE = '2',
65 EL_PIPE_INV_CASCADE = '3',
66 EL_PIPE_BOUNCE = '4',
67 EL_PIPE_INV_BOUNCE = '5',
68};
69
70struct el15203000_led {
71 struct el15203000 *priv;
72 struct led_classdev ldev;
73 u32 reg;
74};
75
76struct 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
85static 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
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
128static 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
138static 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
157static 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
181static 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
191static 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
233static 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
242static 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 fwnode_property_read_string(child, "linux,default-trigger",
267 &led->ldev.default_trigger);
268
269 led->priv = priv;
270 led->ldev.max_brightness = LED_ON;
271 led->ldev.brightness_set_blocking = el15203000_set_blocking;
272
273 if (led->reg == 'S') {
274 led->ldev.pattern_set = el15203000_pattern_set_S;
275 led->ldev.pattern_clear = el15203000_pattern_clear;
276 } else if (led->reg == 'P') {
277 led->ldev.pattern_set = el15203000_pattern_set_P;
278 led->ldev.pattern_clear = el15203000_pattern_clear;
279 }
280
281 init_data.fwnode = child;
282 ret = devm_led_classdev_register_ext(priv->dev, &led->ldev,
283 &init_data);
284 if (ret) {
285 dev_err(priv->dev,
286 "failed to register LED device %s, err %d",
287 led->ldev.name, ret);
288 fwnode_handle_put(child);
289
290 break;
291 }
292
293 led++;
294 }
295
296 return ret;
297}
298
299static int el15203000_probe(struct spi_device *spi)
300{
301 struct el15203000 *priv;
302 size_t count;
303
304 count = device_get_child_node_count(&spi->dev);
305 if (!count) {
306 dev_err(&spi->dev, "LEDs are not defined in device tree!");
307 return -ENODEV;
308 }
309
310 priv = devm_kzalloc(&spi->dev, struct_size(priv, leds, count),
311 GFP_KERNEL);
312 if (!priv)
313 return -ENOMEM;
314
315 mutex_init(&priv->lock);
316 priv->count = count;
317 priv->dev = &spi->dev;
318 priv->spi = spi;
319 priv->delay = jiffies -
320 usecs_to_jiffies(EL_FW_DELAY_USEC);
321
322 spi_set_drvdata(spi, priv);
323
324 return el15203000_probe_dt(priv);
325}
326
327static int el15203000_remove(struct spi_device *spi)
328{
329 struct el15203000 *priv = spi_get_drvdata(spi);
330
331 mutex_destroy(&priv->lock);
332
333 return 0;
334}
335
336static const struct of_device_id el15203000_dt_ids[] = {
337 { .compatible = "crane,el15203000", },
338 {},
339};
340
341MODULE_DEVICE_TABLE(of, el15203000_dt_ids);
342
343static struct spi_driver el15203000_driver = {
344 .probe = el15203000_probe,
345 .remove = el15203000_remove,
346 .driver = {
347 .name = KBUILD_MODNAME,
348 .of_match_table = el15203000_dt_ids,
349 },
350};
351
352module_spi_driver(el15203000_driver);
353
354MODULE_AUTHOR("Oleh Kravchenko <oleg@kaa.org.ua>");
355MODULE_DESCRIPTION("el15203000 LED driver");
356MODULE_LICENSE("GPL v2");
357MODULE_ALIAS("spi:el15203000");
358
