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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2015-16 Golden Delicious Computers
4 *
5 * Author: Nikolaus Schaller <hns@goldelico.com>
6 *
7 * LED driver for the IS31FL319{0,1,3,6,9} to drive 1, 3, 6 or 9 light
8 * effect LEDs.
9 */
10
11#include <linux/err.h>
12#include <linux/i2c.h>
13#include <linux/leds.h>
14#include <linux/mod_devicetable.h>
15#include <linux/module.h>
16#include <linux/property.h>
17#include <linux/regmap.h>
18#include <linux/slab.h>
19#include <linux/delay.h>
20#include <linux/gpio/consumer.h>
21
22/* register numbers */
23#define IS31FL319X_SHUTDOWN 0x00
24
25/* registers for 3190, 3191 and 3193 */
26#define IS31FL3190_BREATHING 0x01
27#define IS31FL3190_LEDMODE 0x02
28#define IS31FL3190_CURRENT 0x03
29#define IS31FL3190_PWM(channel) (0x04 + channel)
30#define IS31FL3190_DATA_UPDATE 0x07
31#define IS31FL3190_T0(channel) (0x0a + channel)
32#define IS31FL3190_T1T2(channel) (0x10 + channel)
33#define IS31FL3190_T3T4(channel) (0x16 + channel)
34#define IS31FL3190_TIME_UPDATE 0x1c
35#define IS31FL3190_LEDCONTROL 0x1d
36#define IS31FL3190_RESET 0x2f
37
38#define IS31FL3190_CURRENT_uA_MIN 5000
39#define IS31FL3190_CURRENT_uA_DEFAULT 42000
40#define IS31FL3190_CURRENT_uA_MAX 42000
41#define IS31FL3190_CURRENT_SHIFT 2
42#define IS31FL3190_CURRENT_MASK GENMASK(4, 2)
43#define IS31FL3190_CURRENT_5_mA 0x02
44#define IS31FL3190_CURRENT_10_mA 0x01
45#define IS31FL3190_CURRENT_17dot5_mA 0x04
46#define IS31FL3190_CURRENT_30_mA 0x03
47#define IS31FL3190_CURRENT_42_mA 0x00
48
49/* registers for 3196 and 3199 */
50#define IS31FL3196_CTRL1 0x01
51#define IS31FL3196_CTRL2 0x02
52#define IS31FL3196_CONFIG1 0x03
53#define IS31FL3196_CONFIG2 0x04
54#define IS31FL3196_RAMP_MODE 0x05
55#define IS31FL3196_BREATH_MARK 0x06
56#define IS31FL3196_PWM(channel) (0x07 + channel)
57#define IS31FL3196_DATA_UPDATE 0x10
58#define IS31FL3196_T0(channel) (0x11 + channel)
59#define IS31FL3196_T123_1 0x1a
60#define IS31FL3196_T123_2 0x1b
61#define IS31FL3196_T123_3 0x1c
62#define IS31FL3196_T4(channel) (0x1d + channel)
63#define IS31FL3196_TIME_UPDATE 0x26
64#define IS31FL3196_RESET 0xff
65
66#define IS31FL3196_REG_CNT (IS31FL3196_RESET + 1)
67
68#define IS31FL319X_MAX_LEDS 9
69
70/* CS (Current Setting) in CONFIG2 register */
71#define IS31FL3196_CONFIG2_CS_SHIFT 4
72#define IS31FL3196_CONFIG2_CS_MASK GENMASK(2, 0)
73#define IS31FL3196_CONFIG2_CS_STEP_REF 12
74
75#define IS31FL3196_CURRENT_uA_MIN 5000
76#define IS31FL3196_CURRENT_uA_MAX 40000
77#define IS31FL3196_CURRENT_uA_STEP 5000
78#define IS31FL3196_CURRENT_uA_DEFAULT 20000
79
80/* Audio gain in CONFIG2 register */
81#define IS31FL3196_AUDIO_GAIN_DB_MAX ((u32)21)
82#define IS31FL3196_AUDIO_GAIN_DB_STEP 3
83
84/*
85 * regmap is used as a cache of chip's register space,
86 * to avoid reading back brightness values from chip,
87 * which is known to hang.
88 */
89struct is31fl319x_chip {
90 const struct is31fl319x_chipdef *cdef;
91 struct i2c_client *client;
92 struct gpio_desc *shutdown_gpio;
93 struct regmap *regmap;
94 struct mutex lock;
95 u32 audio_gain_db;
96
97 struct is31fl319x_led {
98 struct is31fl319x_chip *chip;
99 struct led_classdev cdev;
100 u32 max_microamp;
101 bool configured;
102 } leds[IS31FL319X_MAX_LEDS];
103};
104
105struct is31fl319x_chipdef {
106 int num_leds;
107 u8 reset_reg;
108 const struct regmap_config *is31fl319x_regmap_config;
109 int (*brightness_set)(struct led_classdev *cdev, enum led_brightness brightness);
110 u32 current_default;
111 u32 current_min;
112 u32 current_max;
113 bool is_3196or3199;
114};
115
116static bool is31fl319x_readable_reg(struct device *dev, unsigned int reg)
117{
118 /* we have no readable registers */
119 return false;
120}
121
122static bool is31fl3190_volatile_reg(struct device *dev, unsigned int reg)
123{
124 /* volatile registers are not cached */
125 switch (reg) {
126 case IS31FL3190_DATA_UPDATE:
127 case IS31FL3190_TIME_UPDATE:
128 case IS31FL3190_RESET:
129 return true; /* always write-through */
130 default:
131 return false;
132 }
133}
134
135static const struct reg_default is31fl3190_reg_defaults[] = {
136 { IS31FL3190_LEDMODE, 0x00 },
137 { IS31FL3190_CURRENT, 0x00 },
138 { IS31FL3190_PWM(0), 0x00 },
139 { IS31FL3190_PWM(1), 0x00 },
140 { IS31FL3190_PWM(2), 0x00 },
141};
142
143static const struct regmap_config is31fl3190_regmap_config = {
144 .reg_bits = 8,
145 .val_bits = 8,
146 .max_register = IS31FL3190_RESET,
147 .cache_type = REGCACHE_FLAT,
148 .readable_reg = is31fl319x_readable_reg,
149 .volatile_reg = is31fl3190_volatile_reg,
150 .reg_defaults = is31fl3190_reg_defaults,
151 .num_reg_defaults = ARRAY_SIZE(is31fl3190_reg_defaults),
152};
153
154static bool is31fl3196_volatile_reg(struct device *dev, unsigned int reg)
155{
156 /* volatile registers are not cached */
157 switch (reg) {
158 case IS31FL3196_DATA_UPDATE:
159 case IS31FL3196_TIME_UPDATE:
160 case IS31FL3196_RESET:
161 return true; /* always write-through */
162 default:
163 return false;
164 }
165}
166
167static const struct reg_default is31fl3196_reg_defaults[] = {
168 { IS31FL3196_CONFIG1, 0x00 },
169 { IS31FL3196_CONFIG2, 0x00 },
170 { IS31FL3196_PWM(0), 0x00 },
171 { IS31FL3196_PWM(1), 0x00 },
172 { IS31FL3196_PWM(2), 0x00 },
173 { IS31FL3196_PWM(3), 0x00 },
174 { IS31FL3196_PWM(4), 0x00 },
175 { IS31FL3196_PWM(5), 0x00 },
176 { IS31FL3196_PWM(6), 0x00 },
177 { IS31FL3196_PWM(7), 0x00 },
178 { IS31FL3196_PWM(8), 0x00 },
179};
180
181static const struct regmap_config is31fl3196_regmap_config = {
182 .reg_bits = 8,
183 .val_bits = 8,
184 .max_register = IS31FL3196_REG_CNT,
185 .cache_type = REGCACHE_FLAT,
186 .readable_reg = is31fl319x_readable_reg,
187 .volatile_reg = is31fl3196_volatile_reg,
188 .reg_defaults = is31fl3196_reg_defaults,
189 .num_reg_defaults = ARRAY_SIZE(is31fl3196_reg_defaults),
190};
191
192static int is31fl3190_brightness_set(struct led_classdev *cdev,
193 enum led_brightness brightness)
194{
195 struct is31fl319x_led *led = container_of(cdev, struct is31fl319x_led, cdev);
196 struct is31fl319x_chip *is31 = led->chip;
197 int chan = led - is31->leds;
198 int ret;
199 int i;
200 u8 ctrl = 0;
201
202 dev_dbg(&is31->client->dev, "channel %d: %d\n", chan, brightness);
203
204 mutex_lock(&is31->lock);
205
206 /* update PWM register */
207 ret = regmap_write(is31->regmap, IS31FL3190_PWM(chan), brightness);
208 if (ret < 0)
209 goto out;
210
211 /* read current brightness of all PWM channels */
212 for (i = 0; i < is31->cdef->num_leds; i++) {
213 unsigned int pwm_value;
214 bool on;
215
216 /*
217 * since neither cdev nor the chip can provide
218 * the current setting, we read from the regmap cache
219 */
220
221 ret = regmap_read(is31->regmap, IS31FL3190_PWM(i), &pwm_value);
222 on = ret >= 0 && pwm_value > LED_OFF;
223
224 ctrl |= on << i;
225 }
226
227 if (ctrl > 0) {
228 dev_dbg(&is31->client->dev, "power up %02x\n", ctrl);
229 regmap_write(is31->regmap, IS31FL3190_LEDCONTROL, ctrl);
230 /* update PWMs */
231 regmap_write(is31->regmap, IS31FL3190_DATA_UPDATE, 0x00);
232 /* enable chip from shut down and enable all channels */
233 ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x20);
234 } else {
235 dev_dbg(&is31->client->dev, "power down\n");
236 /* shut down (no need to clear LEDCONTROL) */
237 ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x01);
238 }
239
240out:
241 mutex_unlock(&is31->lock);
242
243 return ret;
244}
245
246static int is31fl3196_brightness_set(struct led_classdev *cdev,
247 enum led_brightness brightness)
248{
249 struct is31fl319x_led *led = container_of(cdev, struct is31fl319x_led, cdev);
250 struct is31fl319x_chip *is31 = led->chip;
251 int chan = led - is31->leds;
252 int ret;
253 int i;
254 u8 ctrl1 = 0, ctrl2 = 0;
255
256 dev_dbg(&is31->client->dev, "channel %d: %d\n", chan, brightness);
257
258 mutex_lock(&is31->lock);
259
260 /* update PWM register */
261 ret = regmap_write(is31->regmap, IS31FL3196_PWM(chan), brightness);
262 if (ret < 0)
263 goto out;
264
265 /* read current brightness of all PWM channels */
266 for (i = 0; i < is31->cdef->num_leds; i++) {
267 unsigned int pwm_value;
268 bool on;
269
270 /*
271 * since neither cdev nor the chip can provide
272 * the current setting, we read from the regmap cache
273 */
274
275 ret = regmap_read(is31->regmap, IS31FL3196_PWM(i), &pwm_value);
276 on = ret >= 0 && pwm_value > LED_OFF;
277
278 if (i < 3)
279 ctrl1 |= on << i; /* 0..2 => bit 0..2 */
280 else if (i < 6)
281 ctrl1 |= on << (i + 1); /* 3..5 => bit 4..6 */
282 else
283 ctrl2 |= on << (i - 6); /* 6..8 => bit 0..2 */
284 }
285
286 if (ctrl1 > 0 || ctrl2 > 0) {
287 dev_dbg(&is31->client->dev, "power up %02x %02x\n",
288 ctrl1, ctrl2);
289 regmap_write(is31->regmap, IS31FL3196_CTRL1, ctrl1);
290 regmap_write(is31->regmap, IS31FL3196_CTRL2, ctrl2);
291 /* update PWMs */
292 regmap_write(is31->regmap, IS31FL3196_DATA_UPDATE, 0x00);
293 /* enable chip from shut down */
294 ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x01);
295 } else {
296 dev_dbg(&is31->client->dev, "power down\n");
297 /* shut down (no need to clear CTRL1/2) */
298 ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x00);
299 }
300
301out:
302 mutex_unlock(&is31->lock);
303
304 return ret;
305}
306
307static const struct is31fl319x_chipdef is31fl3190_cdef = {
308 .num_leds = 1,
309 .reset_reg = IS31FL3190_RESET,
310 .is31fl319x_regmap_config = &is31fl3190_regmap_config,
311 .brightness_set = is31fl3190_brightness_set,
312 .current_default = IS31FL3190_CURRENT_uA_DEFAULT,
313 .current_min = IS31FL3190_CURRENT_uA_MIN,
314 .current_max = IS31FL3190_CURRENT_uA_MAX,
315 .is_3196or3199 = false,
316};
317
318static const struct is31fl319x_chipdef is31fl3193_cdef = {
319 .num_leds = 3,
320 .reset_reg = IS31FL3190_RESET,
321 .is31fl319x_regmap_config = &is31fl3190_regmap_config,
322 .brightness_set = is31fl3190_brightness_set,
323 .current_default = IS31FL3190_CURRENT_uA_DEFAULT,
324 .current_min = IS31FL3190_CURRENT_uA_MIN,
325 .current_max = IS31FL3190_CURRENT_uA_MAX,
326 .is_3196or3199 = false,
327};
328
329static const struct is31fl319x_chipdef is31fl3196_cdef = {
330 .num_leds = 6,
331 .reset_reg = IS31FL3196_RESET,
332 .is31fl319x_regmap_config = &is31fl3196_regmap_config,
333 .brightness_set = is31fl3196_brightness_set,
334 .current_default = IS31FL3196_CURRENT_uA_DEFAULT,
335 .current_min = IS31FL3196_CURRENT_uA_MIN,
336 .current_max = IS31FL3196_CURRENT_uA_MAX,
337 .is_3196or3199 = true,
338};
339
340static const struct is31fl319x_chipdef is31fl3199_cdef = {
341 .num_leds = 9,
342 .reset_reg = IS31FL3196_RESET,
343 .is31fl319x_regmap_config = &is31fl3196_regmap_config,
344 .brightness_set = is31fl3196_brightness_set,
345 .current_default = IS31FL3196_CURRENT_uA_DEFAULT,
346 .current_min = IS31FL3196_CURRENT_uA_MIN,
347 .current_max = IS31FL3196_CURRENT_uA_MAX,
348 .is_3196or3199 = true,
349};
350
351static const struct of_device_id of_is31fl319x_match[] = {
352 { .compatible = "issi,is31fl3190", .data = &is31fl3190_cdef, },
353 { .compatible = "issi,is31fl3191", .data = &is31fl3190_cdef, },
354 { .compatible = "issi,is31fl3193", .data = &is31fl3193_cdef, },
355 { .compatible = "issi,is31fl3196", .data = &is31fl3196_cdef, },
356 { .compatible = "issi,is31fl3199", .data = &is31fl3199_cdef, },
357 { .compatible = "si-en,sn3190", .data = &is31fl3190_cdef, },
358 { .compatible = "si-en,sn3191", .data = &is31fl3190_cdef, },
359 { .compatible = "si-en,sn3193", .data = &is31fl3193_cdef, },
360 { .compatible = "si-en,sn3196", .data = &is31fl3196_cdef, },
361 { .compatible = "si-en,sn3199", .data = &is31fl3199_cdef, },
362 { }
363};
364MODULE_DEVICE_TABLE(of, of_is31fl319x_match);
365
366static int is31fl319x_parse_child_fw(const struct device *dev,
367 const struct fwnode_handle *child,
368 struct is31fl319x_led *led,
369 struct is31fl319x_chip *is31)
370{
371 struct led_classdev *cdev = &led->cdev;
372 int ret;
373
374 if (fwnode_property_read_string(child, "label", &cdev->name))
375 cdev->name = fwnode_get_name(child);
376
377 ret = fwnode_property_read_string(child, "linux,default-trigger", &cdev->default_trigger);
378 if (ret < 0 && ret != -EINVAL) /* is optional */
379 return ret;
380
381 led->max_microamp = is31->cdef->current_default;
382 ret = fwnode_property_read_u32(child, "led-max-microamp", &led->max_microamp);
383 if (!ret) {
384 if (led->max_microamp < is31->cdef->current_min)
385 return -EINVAL; /* not supported */
386 led->max_microamp = min(led->max_microamp,
387 is31->cdef->current_max);
388 }
389
390 return 0;
391}
392
393static int is31fl319x_parse_fw(struct device *dev, struct is31fl319x_chip *is31)
394{
395 struct fwnode_handle *fwnode = dev_fwnode(dev);
396 int count;
397 int ret;
398
399 is31->shutdown_gpio = devm_gpiod_get_optional(dev, "shutdown", GPIOD_OUT_HIGH);
400 if (IS_ERR(is31->shutdown_gpio))
401 return dev_err_probe(dev, PTR_ERR(is31->shutdown_gpio),
402 "Failed to get shutdown gpio\n");
403
404 is31->cdef = device_get_match_data(dev);
405
406 count = 0;
407 device_for_each_child_node_scoped(dev, child)
408 count++;
409
410 dev_dbg(dev, "probing with %d leds defined in DT\n", count);
411
412 if (!count || count > is31->cdef->num_leds)
413 return dev_err_probe(dev, -ENODEV,
414 "Number of leds defined must be between 1 and %u\n",
415 is31->cdef->num_leds);
416
417 device_for_each_child_node_scoped(dev, child) {
418 struct is31fl319x_led *led;
419 u32 reg;
420
421 ret = fwnode_property_read_u32(child, "reg", ®);
422 if (ret)
423 return dev_err_probe(dev, ret, "Failed to read led 'reg' property\n");
424
425 if (reg < 1 || reg > is31->cdef->num_leds)
426 return dev_err_probe(dev, -EINVAL, "invalid led reg %u\n", reg);
427
428 led = &is31->leds[reg - 1];
429
430 if (led->configured)
431 return dev_err_probe(dev, -EINVAL, "led %u is already configured\n", reg);
432
433 ret = is31fl319x_parse_child_fw(dev, child, led, is31);
434 if (ret)
435 return dev_err_probe(dev, ret, "led %u DT parsing failed\n", reg);
436
437 led->configured = true;
438 }
439
440 is31->audio_gain_db = 0;
441 if (is31->cdef->is_3196or3199) {
442 ret = fwnode_property_read_u32(fwnode, "audio-gain-db", &is31->audio_gain_db);
443 if (!ret)
444 is31->audio_gain_db = min(is31->audio_gain_db,
445 IS31FL3196_AUDIO_GAIN_DB_MAX);
446 }
447
448 return 0;
449}
450
451static inline int is31fl3190_microamp_to_cs(struct device *dev, u32 microamp)
452{
453 switch (microamp) {
454 case 5000:
455 return IS31FL3190_CURRENT_5_mA;
456 case 10000:
457 return IS31FL3190_CURRENT_10_mA;
458 case 17500:
459 return IS31FL3190_CURRENT_17dot5_mA;
460 case 30000:
461 return IS31FL3190_CURRENT_30_mA;
462 case 42000:
463 return IS31FL3190_CURRENT_42_mA;
464 default:
465 dev_warn(dev, "Unsupported current value: %d, using 5000 µA!\n", microamp);
466 return IS31FL3190_CURRENT_5_mA;
467 }
468}
469
470static inline int is31fl3196_microamp_to_cs(struct device *dev, u32 microamp)
471{
472 /* round down to nearest supported value (range check done by caller) */
473 u32 step = microamp / IS31FL3196_CURRENT_uA_STEP;
474
475 return ((IS31FL3196_CONFIG2_CS_STEP_REF - step) &
476 IS31FL3196_CONFIG2_CS_MASK) <<
477 IS31FL3196_CONFIG2_CS_SHIFT; /* CS encoding */
478}
479
480static inline int is31fl3196_db_to_gain(u32 dezibel)
481{
482 /* round down to nearest supported value (range check done by caller) */
483 return dezibel / IS31FL3196_AUDIO_GAIN_DB_STEP;
484}
485
486static void is31f1319x_mutex_destroy(void *lock)
487{
488 mutex_destroy(lock);
489}
490
491static int is31fl319x_probe(struct i2c_client *client)
492{
493 struct is31fl319x_chip *is31;
494 struct device *dev = &client->dev;
495 int err;
496 int i = 0;
497 u32 aggregated_led_microamp;
498
499 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
500 return -EIO;
501
502 is31 = devm_kzalloc(&client->dev, sizeof(*is31), GFP_KERNEL);
503 if (!is31)
504 return -ENOMEM;
505
506 mutex_init(&is31->lock);
507 err = devm_add_action_or_reset(dev, is31f1319x_mutex_destroy, &is31->lock);
508 if (err)
509 return err;
510
511 err = is31fl319x_parse_fw(&client->dev, is31);
512 if (err)
513 return err;
514
515 if (is31->shutdown_gpio) {
516 gpiod_direction_output(is31->shutdown_gpio, 0);
517 mdelay(5);
518 gpiod_direction_output(is31->shutdown_gpio, 1);
519 }
520
521 is31->client = client;
522 is31->regmap = devm_regmap_init_i2c(client, is31->cdef->is31fl319x_regmap_config);
523 if (IS_ERR(is31->regmap))
524 return dev_err_probe(dev, PTR_ERR(is31->regmap), "failed to allocate register map\n");
525
526 i2c_set_clientdata(client, is31);
527
528 /* check for write-reply from chip (we can't read any registers) */
529 err = regmap_write(is31->regmap, is31->cdef->reset_reg, 0x00);
530 if (err < 0)
531 return dev_err_probe(dev, err, "no response from chip write\n");
532
533 /*
534 * Kernel conventions require per-LED led-max-microamp property.
535 * But the chip does not allow to limit individual LEDs.
536 * So we take minimum from all subnodes for safety of hardware.
537 */
538 aggregated_led_microamp = is31->cdef->current_max;
539 for (i = 0; i < is31->cdef->num_leds; i++)
540 if (is31->leds[i].configured &&
541 is31->leds[i].max_microamp < aggregated_led_microamp)
542 aggregated_led_microamp = is31->leds[i].max_microamp;
543
544 if (is31->cdef->is_3196or3199)
545 regmap_write(is31->regmap, IS31FL3196_CONFIG2,
546 is31fl3196_microamp_to_cs(dev, aggregated_led_microamp) |
547 is31fl3196_db_to_gain(is31->audio_gain_db));
548 else
549 regmap_update_bits(is31->regmap, IS31FL3190_CURRENT, IS31FL3190_CURRENT_MASK,
550 is31fl3190_microamp_to_cs(dev, aggregated_led_microamp) << IS31FL3190_CURRENT_SHIFT);
551
552 for (i = 0; i < is31->cdef->num_leds; i++) {
553 struct is31fl319x_led *led = &is31->leds[i];
554
555 if (!led->configured)
556 continue;
557
558 led->chip = is31;
559 led->cdev.brightness_set_blocking = is31->cdef->brightness_set;
560
561 err = devm_led_classdev_register(&client->dev, &led->cdev);
562 if (err < 0)
563 return err;
564 }
565
566 return 0;
567}
568
569/*
570 * i2c-core (and modalias) requires that id_table be properly filled,
571 * even though it is not used for DeviceTree based instantiation.
572 */
573static const struct i2c_device_id is31fl319x_id[] = {
574 { "is31fl3190" },
575 { "is31fl3191" },
576 { "is31fl3193" },
577 { "is31fl3196" },
578 { "is31fl3199" },
579 { "sn3190" },
580 { "sn3191" },
581 { "sn3193" },
582 { "sn3196" },
583 { "sn3199" },
584 {},
585};
586MODULE_DEVICE_TABLE(i2c, is31fl319x_id);
587
588static struct i2c_driver is31fl319x_driver = {
589 .driver = {
590 .name = "leds-is31fl319x",
591 .of_match_table = of_is31fl319x_match,
592 },
593 .probe = is31fl319x_probe,
594 .id_table = is31fl319x_id,
595};
596
597module_i2c_driver(is31fl319x_driver);
598
599MODULE_AUTHOR("H. Nikolaus Schaller <hns@goldelico.com>");
600MODULE_AUTHOR("Andrey Utkin <andrey_utkin@fastmail.com>");
601MODULE_DESCRIPTION("IS31FL319X LED driver");
602MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2015-16 Golden Delicious Computers
4 *
5 * Author: Nikolaus Schaller <hns@goldelico.com>
6 *
7 * LED driver for the IS31FL319{0,1,3,6,9} to drive 1, 3, 6 or 9 light
8 * effect LEDs.
9 */
10
11#include <linux/err.h>
12#include <linux/i2c.h>
13#include <linux/leds.h>
14#include <linux/module.h>
15#include <linux/of.h>
16#include <linux/of_device.h>
17#include <linux/regmap.h>
18#include <linux/slab.h>
19
20/* register numbers */
21#define IS31FL319X_SHUTDOWN 0x00
22#define IS31FL319X_CTRL1 0x01
23#define IS31FL319X_CTRL2 0x02
24#define IS31FL319X_CONFIG1 0x03
25#define IS31FL319X_CONFIG2 0x04
26#define IS31FL319X_RAMP_MODE 0x05
27#define IS31FL319X_BREATH_MASK 0x06
28#define IS31FL319X_PWM(channel) (0x07 + channel)
29#define IS31FL319X_DATA_UPDATE 0x10
30#define IS31FL319X_T0(channel) (0x11 + channel)
31#define IS31FL319X_T123_1 0x1a
32#define IS31FL319X_T123_2 0x1b
33#define IS31FL319X_T123_3 0x1c
34#define IS31FL319X_T4(channel) (0x1d + channel)
35#define IS31FL319X_TIME_UPDATE 0x26
36#define IS31FL319X_RESET 0xff
37
38#define IS31FL319X_REG_CNT (IS31FL319X_RESET + 1)
39
40#define IS31FL319X_MAX_LEDS 9
41
42/* CS (Current Setting) in CONFIG2 register */
43#define IS31FL319X_CONFIG2_CS_SHIFT 4
44#define IS31FL319X_CONFIG2_CS_MASK 0x7
45#define IS31FL319X_CONFIG2_CS_STEP_REF 12
46
47#define IS31FL319X_CURRENT_MIN ((u32)5000)
48#define IS31FL319X_CURRENT_MAX ((u32)40000)
49#define IS31FL319X_CURRENT_STEP ((u32)5000)
50#define IS31FL319X_CURRENT_DEFAULT ((u32)20000)
51
52/* Audio gain in CONFIG2 register */
53#define IS31FL319X_AUDIO_GAIN_DB_MAX ((u32)21)
54#define IS31FL319X_AUDIO_GAIN_DB_STEP ((u32)3)
55
56/*
57 * regmap is used as a cache of chip's register space,
58 * to avoid reading back brightness values from chip,
59 * which is known to hang.
60 */
61struct is31fl319x_chip {
62 const struct is31fl319x_chipdef *cdef;
63 struct i2c_client *client;
64 struct regmap *regmap;
65 struct mutex lock;
66 u32 audio_gain_db;
67
68 struct is31fl319x_led {
69 struct is31fl319x_chip *chip;
70 struct led_classdev cdev;
71 u32 max_microamp;
72 bool configured;
73 } leds[IS31FL319X_MAX_LEDS];
74};
75
76struct is31fl319x_chipdef {
77 int num_leds;
78};
79
80static const struct is31fl319x_chipdef is31fl3190_cdef = {
81 .num_leds = 1,
82};
83
84static const struct is31fl319x_chipdef is31fl3193_cdef = {
85 .num_leds = 3,
86};
87
88static const struct is31fl319x_chipdef is31fl3196_cdef = {
89 .num_leds = 6,
90};
91
92static const struct is31fl319x_chipdef is31fl3199_cdef = {
93 .num_leds = 9,
94};
95
96static const struct of_device_id of_is31fl319x_match[] = {
97 { .compatible = "issi,is31fl3190", .data = &is31fl3190_cdef, },
98 { .compatible = "issi,is31fl3191", .data = &is31fl3190_cdef, },
99 { .compatible = "issi,is31fl3193", .data = &is31fl3193_cdef, },
100 { .compatible = "issi,is31fl3196", .data = &is31fl3196_cdef, },
101 { .compatible = "issi,is31fl3199", .data = &is31fl3199_cdef, },
102 { .compatible = "si-en,sn3199", .data = &is31fl3199_cdef, },
103 { }
104};
105MODULE_DEVICE_TABLE(of, of_is31fl319x_match);
106
107static int is31fl319x_brightness_set(struct led_classdev *cdev,
108 enum led_brightness brightness)
109{
110 struct is31fl319x_led *led = container_of(cdev, struct is31fl319x_led,
111 cdev);
112 struct is31fl319x_chip *is31 = led->chip;
113 int chan = led - is31->leds;
114 int ret;
115 int i;
116 u8 ctrl1 = 0, ctrl2 = 0;
117
118 dev_dbg(&is31->client->dev, "%s %d: %d\n", __func__, chan, brightness);
119
120 mutex_lock(&is31->lock);
121
122 /* update PWM register */
123 ret = regmap_write(is31->regmap, IS31FL319X_PWM(chan), brightness);
124 if (ret < 0)
125 goto out;
126
127 /* read current brightness of all PWM channels */
128 for (i = 0; i < is31->cdef->num_leds; i++) {
129 unsigned int pwm_value;
130 bool on;
131
132 /*
133 * since neither cdev nor the chip can provide
134 * the current setting, we read from the regmap cache
135 */
136
137 ret = regmap_read(is31->regmap, IS31FL319X_PWM(i), &pwm_value);
138 dev_dbg(&is31->client->dev, "%s read %d: ret=%d: %d\n",
139 __func__, i, ret, pwm_value);
140 on = ret >= 0 && pwm_value > LED_OFF;
141
142 if (i < 3)
143 ctrl1 |= on << i; /* 0..2 => bit 0..2 */
144 else if (i < 6)
145 ctrl1 |= on << (i + 1); /* 3..5 => bit 4..6 */
146 else
147 ctrl2 |= on << (i - 6); /* 6..8 => bit 0..2 */
148 }
149
150 if (ctrl1 > 0 || ctrl2 > 0) {
151 dev_dbg(&is31->client->dev, "power up %02x %02x\n",
152 ctrl1, ctrl2);
153 regmap_write(is31->regmap, IS31FL319X_CTRL1, ctrl1);
154 regmap_write(is31->regmap, IS31FL319X_CTRL2, ctrl2);
155 /* update PWMs */
156 regmap_write(is31->regmap, IS31FL319X_DATA_UPDATE, 0x00);
157 /* enable chip from shut down */
158 ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x01);
159 } else {
160 dev_dbg(&is31->client->dev, "power down\n");
161 /* shut down (no need to clear CTRL1/2) */
162 ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x00);
163 }
164
165out:
166 mutex_unlock(&is31->lock);
167
168 return ret;
169}
170
171static int is31fl319x_parse_child_dt(const struct device *dev,
172 const struct device_node *child,
173 struct is31fl319x_led *led)
174{
175 struct led_classdev *cdev = &led->cdev;
176 int ret;
177
178 if (of_property_read_string(child, "label", &cdev->name))
179 cdev->name = child->name;
180
181 ret = of_property_read_string(child, "linux,default-trigger",
182 &cdev->default_trigger);
183 if (ret < 0 && ret != -EINVAL) /* is optional */
184 return ret;
185
186 led->max_microamp = IS31FL319X_CURRENT_DEFAULT;
187 ret = of_property_read_u32(child, "led-max-microamp",
188 &led->max_microamp);
189 if (!ret) {
190 if (led->max_microamp < IS31FL319X_CURRENT_MIN)
191 return -EINVAL; /* not supported */
192 led->max_microamp = min(led->max_microamp,
193 IS31FL319X_CURRENT_MAX);
194 }
195
196 return 0;
197}
198
199static int is31fl319x_parse_dt(struct device *dev,
200 struct is31fl319x_chip *is31)
201{
202 struct device_node *np = dev->of_node, *child;
203 const struct of_device_id *of_dev_id;
204 int count;
205 int ret;
206
207 if (!np)
208 return -ENODEV;
209
210 of_dev_id = of_match_device(of_is31fl319x_match, dev);
211 if (!of_dev_id) {
212 dev_err(dev, "Failed to match device with supported chips\n");
213 return -EINVAL;
214 }
215
216 is31->cdef = of_dev_id->data;
217
218 count = of_get_child_count(np);
219
220 dev_dbg(dev, "probe %s with %d leds defined in DT\n",
221 of_dev_id->compatible, count);
222
223 if (!count || count > is31->cdef->num_leds) {
224 dev_err(dev, "Number of leds defined must be between 1 and %u\n",
225 is31->cdef->num_leds);
226 return -ENODEV;
227 }
228
229 for_each_child_of_node(np, child) {
230 struct is31fl319x_led *led;
231 u32 reg;
232
233 ret = of_property_read_u32(child, "reg", ®);
234 if (ret) {
235 dev_err(dev, "Failed to read led 'reg' property\n");
236 goto put_child_node;
237 }
238
239 if (reg < 1 || reg > is31->cdef->num_leds) {
240 dev_err(dev, "invalid led reg %u\n", reg);
241 ret = -EINVAL;
242 goto put_child_node;
243 }
244
245 led = &is31->leds[reg - 1];
246
247 if (led->configured) {
248 dev_err(dev, "led %u is already configured\n", reg);
249 ret = -EINVAL;
250 goto put_child_node;
251 }
252
253 ret = is31fl319x_parse_child_dt(dev, child, led);
254 if (ret) {
255 dev_err(dev, "led %u DT parsing failed\n", reg);
256 goto put_child_node;
257 }
258
259 led->configured = true;
260 }
261
262 is31->audio_gain_db = 0;
263 ret = of_property_read_u32(np, "audio-gain-db", &is31->audio_gain_db);
264 if (!ret)
265 is31->audio_gain_db = min(is31->audio_gain_db,
266 IS31FL319X_AUDIO_GAIN_DB_MAX);
267
268 return 0;
269
270put_child_node:
271 of_node_put(child);
272 return ret;
273}
274
275static bool is31fl319x_readable_reg(struct device *dev, unsigned int reg)
276{ /* we have no readable registers */
277 return false;
278}
279
280static bool is31fl319x_volatile_reg(struct device *dev, unsigned int reg)
281{ /* volatile registers are not cached */
282 switch (reg) {
283 case IS31FL319X_DATA_UPDATE:
284 case IS31FL319X_TIME_UPDATE:
285 case IS31FL319X_RESET:
286 return true; /* always write-through */
287 default:
288 return false;
289 }
290}
291
292static const struct reg_default is31fl319x_reg_defaults[] = {
293 { IS31FL319X_CONFIG1, 0x00},
294 { IS31FL319X_CONFIG2, 0x00},
295 { IS31FL319X_PWM(0), 0x00},
296 { IS31FL319X_PWM(1), 0x00},
297 { IS31FL319X_PWM(2), 0x00},
298 { IS31FL319X_PWM(3), 0x00},
299 { IS31FL319X_PWM(4), 0x00},
300 { IS31FL319X_PWM(5), 0x00},
301 { IS31FL319X_PWM(6), 0x00},
302 { IS31FL319X_PWM(7), 0x00},
303 { IS31FL319X_PWM(8), 0x00},
304};
305
306static struct regmap_config regmap_config = {
307 .reg_bits = 8,
308 .val_bits = 8,
309 .max_register = IS31FL319X_REG_CNT,
310 .cache_type = REGCACHE_FLAT,
311 .readable_reg = is31fl319x_readable_reg,
312 .volatile_reg = is31fl319x_volatile_reg,
313 .reg_defaults = is31fl319x_reg_defaults,
314 .num_reg_defaults = ARRAY_SIZE(is31fl319x_reg_defaults),
315};
316
317static inline int is31fl319x_microamp_to_cs(struct device *dev, u32 microamp)
318{ /* round down to nearest supported value (range check done by caller) */
319 u32 step = microamp / IS31FL319X_CURRENT_STEP;
320
321 return ((IS31FL319X_CONFIG2_CS_STEP_REF - step) &
322 IS31FL319X_CONFIG2_CS_MASK) <<
323 IS31FL319X_CONFIG2_CS_SHIFT; /* CS encoding */
324}
325
326static inline int is31fl319x_db_to_gain(u32 dezibel)
327{ /* round down to nearest supported value (range check done by caller) */
328 return dezibel / IS31FL319X_AUDIO_GAIN_DB_STEP;
329}
330
331static int is31fl319x_probe(struct i2c_client *client,
332 const struct i2c_device_id *id)
333{
334 struct is31fl319x_chip *is31;
335 struct device *dev = &client->dev;
336 int err;
337 int i = 0;
338 u32 aggregated_led_microamp = IS31FL319X_CURRENT_MAX;
339
340 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
341 return -EIO;
342
343 is31 = devm_kzalloc(&client->dev, sizeof(*is31), GFP_KERNEL);
344 if (!is31)
345 return -ENOMEM;
346
347 mutex_init(&is31->lock);
348
349 err = is31fl319x_parse_dt(&client->dev, is31);
350 if (err)
351 goto free_mutex;
352
353 is31->client = client;
354 is31->regmap = devm_regmap_init_i2c(client, ®map_config);
355 if (IS_ERR(is31->regmap)) {
356 dev_err(&client->dev, "failed to allocate register map\n");
357 err = PTR_ERR(is31->regmap);
358 goto free_mutex;
359 }
360
361 i2c_set_clientdata(client, is31);
362
363 /* check for write-reply from chip (we can't read any registers) */
364 err = regmap_write(is31->regmap, IS31FL319X_RESET, 0x00);
365 if (err < 0) {
366 dev_err(&client->dev, "no response from chip write: err = %d\n",
367 err);
368 err = -EIO; /* does not answer */
369 goto free_mutex;
370 }
371
372 /*
373 * Kernel conventions require per-LED led-max-microamp property.
374 * But the chip does not allow to limit individual LEDs.
375 * So we take minimum from all subnodes for safety of hardware.
376 */
377 for (i = 0; i < is31->cdef->num_leds; i++)
378 if (is31->leds[i].configured &&
379 is31->leds[i].max_microamp < aggregated_led_microamp)
380 aggregated_led_microamp = is31->leds[i].max_microamp;
381
382 regmap_write(is31->regmap, IS31FL319X_CONFIG2,
383 is31fl319x_microamp_to_cs(dev, aggregated_led_microamp) |
384 is31fl319x_db_to_gain(is31->audio_gain_db));
385
386 for (i = 0; i < is31->cdef->num_leds; i++) {
387 struct is31fl319x_led *led = &is31->leds[i];
388
389 if (!led->configured)
390 continue;
391
392 led->chip = is31;
393 led->cdev.brightness_set_blocking = is31fl319x_brightness_set;
394
395 err = devm_led_classdev_register(&client->dev, &led->cdev);
396 if (err < 0)
397 goto free_mutex;
398 }
399
400 return 0;
401
402free_mutex:
403 mutex_destroy(&is31->lock);
404 return err;
405}
406
407static int is31fl319x_remove(struct i2c_client *client)
408{
409 struct is31fl319x_chip *is31 = i2c_get_clientdata(client);
410
411 mutex_destroy(&is31->lock);
412 return 0;
413}
414
415/*
416 * i2c-core (and modalias) requires that id_table be properly filled,
417 * even though it is not used for DeviceTree based instantiation.
418 */
419static const struct i2c_device_id is31fl319x_id[] = {
420 { "is31fl3190" },
421 { "is31fl3191" },
422 { "is31fl3193" },
423 { "is31fl3196" },
424 { "is31fl3199" },
425 { "sn3199" },
426 {},
427};
428MODULE_DEVICE_TABLE(i2c, is31fl319x_id);
429
430static struct i2c_driver is31fl319x_driver = {
431 .driver = {
432 .name = "leds-is31fl319x",
433 .of_match_table = of_match_ptr(of_is31fl319x_match),
434 },
435 .probe = is31fl319x_probe,
436 .remove = is31fl319x_remove,
437 .id_table = is31fl319x_id,
438};
439
440module_i2c_driver(is31fl319x_driver);
441
442MODULE_AUTHOR("H. Nikolaus Schaller <hns@goldelico.com>");
443MODULE_AUTHOR("Andrey Utkin <andrey_utkin@fastmail.com>");
444MODULE_DESCRIPTION("IS31FL319X LED driver");
445MODULE_LICENSE("GPL v2");