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5#include <linux/delay.h>
6#include <linux/leds.h>
7#include <linux/mod_devicetable.h>
8#include <linux/module.h>
9#include <linux/property.h>
10#include <linux/spi/spi.h>
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51#define EL_FW_DELAY_USEC 20000ul
52#define EL_PATTERN_DELAY_MSEC 800u
53#define EL_PATTERN_LEN 10u
54#define EL_PATTERN_HALF_LEN (EL_PATTERN_LEN / 2)
55
56enum el15203000_command {
57
58 EL_OFF = '0',
59 EL_ON = '1',
60
61
62 EL_SCREEN_BREATHING = '2',
63
64
65 EL_PIPE_CASCADE = '2',
66 EL_PIPE_INV_CASCADE = '3',
67 EL_PIPE_BOUNCE = '4',
68 EL_PIPE_INV_BOUNCE = '5',
69};
70
71struct el15203000_led {
72 struct led_classdev ldev;
73 struct el15203000 *priv;
74 u32 reg;
75};
76
77struct el15203000 {
78 struct device *dev;
79 struct mutex lock;
80 struct spi_device *spi;
81 unsigned long delay;
82 size_t count;
83 struct el15203000_led leds[];
84};
85
86#define to_el15203000_led(d) container_of(d, struct el15203000_led, ldev)
87
88static int el15203000_cmd(struct el15203000_led *led, u8 brightness)
89{
90 int ret;
91 u8 cmd[2];
92 size_t i;
93
94 mutex_lock(&led->priv->lock);
95
96 dev_dbg(led->priv->dev, "Set brightness of 0x%02x(%c) to 0x%02x(%c)",
97 led->reg, led->reg, brightness, brightness);
98
99
100 if (time_after(led->priv->delay, jiffies)) {
101 dev_dbg(led->priv->dev, "Wait %luus to sync",
102 EL_FW_DELAY_USEC);
103
104 usleep_range(EL_FW_DELAY_USEC,
105 EL_FW_DELAY_USEC + 1);
106 }
107
108 cmd[0] = led->reg;
109 cmd[1] = brightness;
110
111 for (i = 0; i < ARRAY_SIZE(cmd); i++) {
112 if (i)
113 usleep_range(EL_FW_DELAY_USEC,
114 EL_FW_DELAY_USEC + 1);
115
116 ret = spi_write(led->priv->spi, &cmd[i], sizeof(cmd[i]));
117 if (ret) {
118 dev_err(led->priv->dev,
119 "spi_write() error %d", ret);
120 break;
121 }
122 }
123
124 led->priv->delay = jiffies + usecs_to_jiffies(EL_FW_DELAY_USEC);
125
126 mutex_unlock(&led->priv->lock);
127
128 return ret;
129}
130
131static int el15203000_set_blocking(struct led_classdev *ldev,
132 enum led_brightness brightness)
133{
134 struct el15203000_led *led = to_el15203000_led(ldev);
135
136 return el15203000_cmd(led, brightness == LED_OFF ? EL_OFF : EL_ON);
137}
138
139static int el15203000_pattern_set_S(struct led_classdev *ldev,
140 struct led_pattern *pattern,
141 u32 len, int repeat)
142{
143 struct el15203000_led *led = to_el15203000_led(ldev);
144
145 if (repeat > 0 || len != 2 ||
146 pattern[0].delta_t != 4000 || pattern[0].brightness != 0 ||
147 pattern[1].delta_t != 4000 || pattern[1].brightness != 1)
148 return -EINVAL;
149
150 dev_dbg(led->priv->dev, "Breathing mode for 0x%02x(%c)",
151 led->reg, led->reg);
152
153 return el15203000_cmd(led, EL_SCREEN_BREATHING);
154}
155
156static bool is_cascade(const struct led_pattern *pattern, u32 len,
157 bool inv, bool right)
158{
159 int val, t;
160 u32 i;
161
162 if (len != EL_PATTERN_HALF_LEN)
163 return false;
164
165 val = right ? BIT(4) : BIT(0);
166
167 for (i = 0; i < len; i++) {
168 t = inv ? ~val & GENMASK(4, 0) : val;
169
170 if (pattern[i].delta_t != EL_PATTERN_DELAY_MSEC ||
171 pattern[i].brightness != t)
172 return false;
173
174 val = right ? val >> 1 : val << 1;
175 }
176
177 return true;
178}
179
180static bool is_bounce(const struct led_pattern *pattern, u32 len, bool inv)
181{
182 if (len != EL_PATTERN_LEN)
183 return false;
184
185 return is_cascade(pattern, EL_PATTERN_HALF_LEN, inv, false) &&
186 is_cascade(pattern + EL_PATTERN_HALF_LEN,
187 EL_PATTERN_HALF_LEN, inv, true);
188}
189
190static int el15203000_pattern_set_P(struct led_classdev *ldev,
191 struct led_pattern *pattern,
192 u32 len, int repeat)
193{
194 struct el15203000_led *led = to_el15203000_led(ldev);
195 u8 cmd;
196
197 if (repeat > 0)
198 return -EINVAL;
199
200 if (is_cascade(pattern, len, false, false)) {
201 dev_dbg(led->priv->dev, "Cascade mode for 0x%02x(%c)",
202 led->reg, led->reg);
203
204 cmd = EL_PIPE_CASCADE;
205 } else if (is_cascade(pattern, len, true, false)) {
206 dev_dbg(led->priv->dev, "Inverse cascade mode for 0x%02x(%c)",
207 led->reg, led->reg);
208
209 cmd = EL_PIPE_INV_CASCADE;
210 } else if (is_bounce(pattern, len, false)) {
211 dev_dbg(led->priv->dev, "Bounce mode for 0x%02x(%c)",
212 led->reg, led->reg);
213
214 cmd = EL_PIPE_BOUNCE;
215 } else if (is_bounce(pattern, len, true)) {
216 dev_dbg(led->priv->dev, "Inverse bounce mode for 0x%02x(%c)",
217 led->reg, led->reg);
218
219 cmd = EL_PIPE_INV_BOUNCE;
220 } else {
221 dev_err(led->priv->dev, "Invalid hw_pattern for 0x%02x(%c)!",
222 led->reg, led->reg);
223
224 return -EINVAL;
225 }
226
227 return el15203000_cmd(led, cmd);
228}
229
230static int el15203000_pattern_clear(struct led_classdev *ldev)
231{
232 struct el15203000_led *led = to_el15203000_led(ldev);
233
234 return el15203000_cmd(led, EL_OFF);
235}
236
237static int el15203000_probe_dt(struct el15203000 *priv)
238{
239 struct el15203000_led *led = priv->leds;
240 struct fwnode_handle *child;
241 int ret;
242
243 device_for_each_child_node(priv->dev, child) {
244 struct led_init_data init_data = {};
245
246 ret = fwnode_property_read_u32(child, "reg", &led->reg);
247 if (ret) {
248 dev_err(priv->dev, "LED without ID number");
249 goto err_child_out;
250 }
251
252 if (led->reg > U8_MAX) {
253 dev_err(priv->dev, "LED value %d is invalid", led->reg);
254 ret = -EINVAL;
255 goto err_child_out;
256 }
257
258 led->priv = priv;
259 led->ldev.max_brightness = LED_ON;
260 led->ldev.brightness_set_blocking = el15203000_set_blocking;
261
262 if (led->reg == 'S') {
263 led->ldev.pattern_set = el15203000_pattern_set_S;
264 led->ldev.pattern_clear = el15203000_pattern_clear;
265 } else if (led->reg == 'P') {
266 led->ldev.pattern_set = el15203000_pattern_set_P;
267 led->ldev.pattern_clear = el15203000_pattern_clear;
268 }
269
270 init_data.fwnode = child;
271 ret = devm_led_classdev_register_ext(priv->dev, &led->ldev,
272 &init_data);
273 if (ret) {
274 dev_err(priv->dev,
275 "failed to register LED device %s, err %d",
276 led->ldev.name, ret);
277 goto err_child_out;
278 }
279
280 led++;
281 }
282
283 return 0;
284
285err_child_out:
286 fwnode_handle_put(child);
287 return ret;
288}
289
290static int el15203000_probe(struct spi_device *spi)
291{
292 struct el15203000 *priv;
293 size_t count;
294
295 count = device_get_child_node_count(&spi->dev);
296 if (!count) {
297 dev_err(&spi->dev, "LEDs are not defined in device tree!");
298 return -ENODEV;
299 }
300
301 priv = devm_kzalloc(&spi->dev, struct_size(priv, leds, count),
302 GFP_KERNEL);
303 if (!priv)
304 return -ENOMEM;
305
306 mutex_init(&priv->lock);
307 priv->count = count;
308 priv->dev = &spi->dev;
309 priv->spi = spi;
310 priv->delay = jiffies -
311 usecs_to_jiffies(EL_FW_DELAY_USEC);
312
313 spi_set_drvdata(spi, priv);
314
315 return el15203000_probe_dt(priv);
316}
317
318static int el15203000_remove(struct spi_device *spi)
319{
320 struct el15203000 *priv = spi_get_drvdata(spi);
321
322 mutex_destroy(&priv->lock);
323
324 return 0;
325}
326
327static const struct of_device_id el15203000_dt_ids[] = {
328 { .compatible = "crane,el15203000", },
329 {},
330};
331
332MODULE_DEVICE_TABLE(of, el15203000_dt_ids);
333
334static struct spi_driver el15203000_driver = {
335 .probe = el15203000_probe,
336 .remove = el15203000_remove,
337 .driver = {
338 .name = KBUILD_MODNAME,
339 .of_match_table = el15203000_dt_ids,
340 },
341};
342
343module_spi_driver(el15203000_driver);
344
345MODULE_AUTHOR("Oleh Kravchenko <oleg@kaa.org.ua>");
346MODULE_DESCRIPTION("el15203000 LED driver");
347MODULE_LICENSE("GPL v2");
348MODULE_ALIAS("spi:el15203000");
349
