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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 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 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), *child;
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 fwnode_for_each_available_child_node(fwnode, 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 fwnode_for_each_available_child_node(fwnode, child) {
418 struct is31fl319x_led *led;
419 u32 reg;
420
421 ret = fwnode_property_read_u32(child, "reg", ®);
422 if (ret) {
423 ret = dev_err_probe(dev, ret, "Failed to read led 'reg' property\n");
424 goto put_child_node;
425 }
426
427 if (reg < 1 || reg > is31->cdef->num_leds) {
428 ret = dev_err_probe(dev, -EINVAL, "invalid led reg %u\n", reg);
429 goto put_child_node;
430 }
431
432 led = &is31->leds[reg - 1];
433
434 if (led->configured) {
435 ret = dev_err_probe(dev, -EINVAL, "led %u is already configured\n", reg);
436 goto put_child_node;
437 }
438
439 ret = is31fl319x_parse_child_fw(dev, child, led, is31);
440 if (ret) {
441 ret = dev_err_probe(dev, ret, "led %u DT parsing failed\n", reg);
442 goto put_child_node;
443 }
444
445 led->configured = true;
446 }
447
448 is31->audio_gain_db = 0;
449 if (is31->cdef->is_3196or3199) {
450 ret = fwnode_property_read_u32(fwnode, "audio-gain-db", &is31->audio_gain_db);
451 if (!ret)
452 is31->audio_gain_db = min(is31->audio_gain_db,
453 IS31FL3196_AUDIO_GAIN_DB_MAX);
454 }
455
456 return 0;
457
458put_child_node:
459 fwnode_handle_put(child);
460 return ret;
461}
462
463static inline int is31fl3190_microamp_to_cs(struct device *dev, u32 microamp)
464{
465 switch (microamp) {
466 case 5000:
467 return IS31FL3190_CURRENT_5_mA;
468 case 10000:
469 return IS31FL3190_CURRENT_10_mA;
470 case 17500:
471 return IS31FL3190_CURRENT_17dot5_mA;
472 case 30000:
473 return IS31FL3190_CURRENT_30_mA;
474 case 42000:
475 return IS31FL3190_CURRENT_42_mA;
476 default:
477 dev_warn(dev, "Unsupported current value: %d, using 5000 µA!\n", microamp);
478 return IS31FL3190_CURRENT_5_mA;
479 }
480}
481
482static inline int is31fl3196_microamp_to_cs(struct device *dev, u32 microamp)
483{
484 /* round down to nearest supported value (range check done by caller) */
485 u32 step = microamp / IS31FL3196_CURRENT_uA_STEP;
486
487 return ((IS31FL3196_CONFIG2_CS_STEP_REF - step) &
488 IS31FL3196_CONFIG2_CS_MASK) <<
489 IS31FL3196_CONFIG2_CS_SHIFT; /* CS encoding */
490}
491
492static inline int is31fl3196_db_to_gain(u32 dezibel)
493{
494 /* round down to nearest supported value (range check done by caller) */
495 return dezibel / IS31FL3196_AUDIO_GAIN_DB_STEP;
496}
497
498static void is31f1319x_mutex_destroy(void *lock)
499{
500 mutex_destroy(lock);
501}
502
503static int is31fl319x_probe(struct i2c_client *client)
504{
505 struct is31fl319x_chip *is31;
506 struct device *dev = &client->dev;
507 int err;
508 int i = 0;
509 u32 aggregated_led_microamp;
510
511 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
512 return -EIO;
513
514 is31 = devm_kzalloc(&client->dev, sizeof(*is31), GFP_KERNEL);
515 if (!is31)
516 return -ENOMEM;
517
518 mutex_init(&is31->lock);
519 err = devm_add_action_or_reset(dev, is31f1319x_mutex_destroy, &is31->lock);
520 if (err)
521 return err;
522
523 err = is31fl319x_parse_fw(&client->dev, is31);
524 if (err)
525 return err;
526
527 if (is31->shutdown_gpio) {
528 gpiod_direction_output(is31->shutdown_gpio, 0);
529 mdelay(5);
530 gpiod_direction_output(is31->shutdown_gpio, 1);
531 }
532
533 is31->client = client;
534 is31->regmap = devm_regmap_init_i2c(client, is31->cdef->is31fl319x_regmap_config);
535 if (IS_ERR(is31->regmap))
536 return dev_err_probe(dev, PTR_ERR(is31->regmap), "failed to allocate register map\n");
537
538 i2c_set_clientdata(client, is31);
539
540 /* check for write-reply from chip (we can't read any registers) */
541 err = regmap_write(is31->regmap, is31->cdef->reset_reg, 0x00);
542 if (err < 0)
543 return dev_err_probe(dev, err, "no response from chip write\n");
544
545 /*
546 * Kernel conventions require per-LED led-max-microamp property.
547 * But the chip does not allow to limit individual LEDs.
548 * So we take minimum from all subnodes for safety of hardware.
549 */
550 aggregated_led_microamp = is31->cdef->current_max;
551 for (i = 0; i < is31->cdef->num_leds; i++)
552 if (is31->leds[i].configured &&
553 is31->leds[i].max_microamp < aggregated_led_microamp)
554 aggregated_led_microamp = is31->leds[i].max_microamp;
555
556 if (is31->cdef->is_3196or3199)
557 regmap_write(is31->regmap, IS31FL3196_CONFIG2,
558 is31fl3196_microamp_to_cs(dev, aggregated_led_microamp) |
559 is31fl3196_db_to_gain(is31->audio_gain_db));
560 else
561 regmap_update_bits(is31->regmap, IS31FL3190_CURRENT, IS31FL3190_CURRENT_MASK,
562 is31fl3190_microamp_to_cs(dev, aggregated_led_microamp) << IS31FL3190_CURRENT_SHIFT);
563
564 for (i = 0; i < is31->cdef->num_leds; i++) {
565 struct is31fl319x_led *led = &is31->leds[i];
566
567 if (!led->configured)
568 continue;
569
570 led->chip = is31;
571 led->cdev.brightness_set_blocking = is31->cdef->brightness_set;
572
573 err = devm_led_classdev_register(&client->dev, &led->cdev);
574 if (err < 0)
575 return err;
576 }
577
578 return 0;
579}
580
581/*
582 * i2c-core (and modalias) requires that id_table be properly filled,
583 * even though it is not used for DeviceTree based instantiation.
584 */
585static const struct i2c_device_id is31fl319x_id[] = {
586 { "is31fl3190" },
587 { "is31fl3191" },
588 { "is31fl3193" },
589 { "is31fl3196" },
590 { "is31fl3199" },
591 { "sn3190" },
592 { "sn3191" },
593 { "sn3193" },
594 { "sn3196" },
595 { "sn3199" },
596 {},
597};
598MODULE_DEVICE_TABLE(i2c, is31fl319x_id);
599
600static struct i2c_driver is31fl319x_driver = {
601 .driver = {
602 .name = "leds-is31fl319x",
603 .of_match_table = of_is31fl319x_match,
604 },
605 .probe = is31fl319x_probe,
606 .id_table = is31fl319x_id,
607};
608
609module_i2c_driver(is31fl319x_driver);
610
611MODULE_AUTHOR("H. Nikolaus Schaller <hns@goldelico.com>");
612MODULE_AUTHOR("Andrey Utkin <andrey_utkin@fastmail.com>");
613MODULE_DESCRIPTION("IS31FL319X LED driver");
614MODULE_LICENSE("GPL v2");
1/*
2 * Copyright 2015-16 Golden Delicious Computers
3 *
4 * Author: Nikolaus Schaller <hns@goldelico.com>
5 *
6 * This file is subject to the terms and conditions of version 2 of
7 * the GNU General Public License. See the file COPYING in the main
8 * directory of this archive for more details.
9 *
10 * LED driver for the IS31FL319{0,1,3,6,9} to drive 1, 3, 6 or 9 light
11 * effect LEDs.
12 *
13 */
14
15#include <linux/err.h>
16#include <linux/i2c.h>
17#include <linux/leds.h>
18#include <linux/module.h>
19#include <linux/of.h>
20#include <linux/of_device.h>
21#include <linux/regmap.h>
22#include <linux/slab.h>
23
24/* register numbers */
25#define IS31FL319X_SHUTDOWN 0x00
26#define IS31FL319X_CTRL1 0x01
27#define IS31FL319X_CTRL2 0x02
28#define IS31FL319X_CONFIG1 0x03
29#define IS31FL319X_CONFIG2 0x04
30#define IS31FL319X_RAMP_MODE 0x05
31#define IS31FL319X_BREATH_MASK 0x06
32#define IS31FL319X_PWM(channel) (0x07 + channel)
33#define IS31FL319X_DATA_UPDATE 0x10
34#define IS31FL319X_T0(channel) (0x11 + channel)
35#define IS31FL319X_T123_1 0x1a
36#define IS31FL319X_T123_2 0x1b
37#define IS31FL319X_T123_3 0x1c
38#define IS31FL319X_T4(channel) (0x1d + channel)
39#define IS31FL319X_TIME_UPDATE 0x26
40#define IS31FL319X_RESET 0xff
41
42#define IS31FL319X_REG_CNT (IS31FL319X_RESET + 1)
43
44#define IS31FL319X_MAX_LEDS 9
45
46/* CS (Current Setting) in CONFIG2 register */
47#define IS31FL319X_CONFIG2_CS_SHIFT 4
48#define IS31FL319X_CONFIG2_CS_MASK 0x7
49#define IS31FL319X_CONFIG2_CS_STEP_REF 12
50
51#define IS31FL319X_CURRENT_MIN ((u32)5000)
52#define IS31FL319X_CURRENT_MAX ((u32)40000)
53#define IS31FL319X_CURRENT_STEP ((u32)5000)
54#define IS31FL319X_CURRENT_DEFAULT ((u32)20000)
55
56/* Audio gain in CONFIG2 register */
57#define IS31FL319X_AUDIO_GAIN_DB_MAX ((u32)21)
58#define IS31FL319X_AUDIO_GAIN_DB_STEP ((u32)3)
59
60/*
61 * regmap is used as a cache of chip's register space,
62 * to avoid reading back brightness values from chip,
63 * which is known to hang.
64 */
65struct is31fl319x_chip {
66 const struct is31fl319x_chipdef *cdef;
67 struct i2c_client *client;
68 struct regmap *regmap;
69 struct mutex lock;
70 u32 audio_gain_db;
71
72 struct is31fl319x_led {
73 struct is31fl319x_chip *chip;
74 struct led_classdev cdev;
75 u32 max_microamp;
76 bool configured;
77 } leds[IS31FL319X_MAX_LEDS];
78};
79
80struct is31fl319x_chipdef {
81 int num_leds;
82};
83
84static const struct is31fl319x_chipdef is31fl3190_cdef = {
85 .num_leds = 1,
86};
87
88static const struct is31fl319x_chipdef is31fl3193_cdef = {
89 .num_leds = 3,
90};
91
92static const struct is31fl319x_chipdef is31fl3196_cdef = {
93 .num_leds = 6,
94};
95
96static const struct is31fl319x_chipdef is31fl3199_cdef = {
97 .num_leds = 9,
98};
99
100static const struct of_device_id of_is31fl319x_match[] = {
101 { .compatible = "issi,is31fl3190", .data = &is31fl3190_cdef, },
102 { .compatible = "issi,is31fl3191", .data = &is31fl3190_cdef, },
103 { .compatible = "issi,is31fl3193", .data = &is31fl3193_cdef, },
104 { .compatible = "issi,is31fl3196", .data = &is31fl3196_cdef, },
105 { .compatible = "issi,is31fl3199", .data = &is31fl3199_cdef, },
106 { .compatible = "si-en,sn3199", .data = &is31fl3199_cdef, },
107 { }
108};
109MODULE_DEVICE_TABLE(of, of_is31fl319x_match);
110
111static int is31fl319x_brightness_set(struct led_classdev *cdev,
112 enum led_brightness brightness)
113{
114 struct is31fl319x_led *led = container_of(cdev, struct is31fl319x_led,
115 cdev);
116 struct is31fl319x_chip *is31 = led->chip;
117 int chan = led - is31->leds;
118 int ret;
119 int i;
120 u8 ctrl1 = 0, ctrl2 = 0;
121
122 dev_dbg(&is31->client->dev, "%s %d: %d\n", __func__, chan, brightness);
123
124 mutex_lock(&is31->lock);
125
126 /* update PWM register */
127 ret = regmap_write(is31->regmap, IS31FL319X_PWM(chan), brightness);
128 if (ret < 0)
129 goto out;
130
131 /* read current brightness of all PWM channels */
132 for (i = 0; i < is31->cdef->num_leds; i++) {
133 unsigned int pwm_value;
134 bool on;
135
136 /*
137 * since neither cdev nor the chip can provide
138 * the current setting, we read from the regmap cache
139 */
140
141 ret = regmap_read(is31->regmap, IS31FL319X_PWM(i), &pwm_value);
142 dev_dbg(&is31->client->dev, "%s read %d: ret=%d: %d\n",
143 __func__, i, ret, pwm_value);
144 on = ret >= 0 && pwm_value > LED_OFF;
145
146 if (i < 3)
147 ctrl1 |= on << i; /* 0..2 => bit 0..2 */
148 else if (i < 6)
149 ctrl1 |= on << (i + 1); /* 3..5 => bit 4..6 */
150 else
151 ctrl2 |= on << (i - 6); /* 6..8 => bit 0..2 */
152 }
153
154 if (ctrl1 > 0 || ctrl2 > 0) {
155 dev_dbg(&is31->client->dev, "power up %02x %02x\n",
156 ctrl1, ctrl2);
157 regmap_write(is31->regmap, IS31FL319X_CTRL1, ctrl1);
158 regmap_write(is31->regmap, IS31FL319X_CTRL2, ctrl2);
159 /* update PWMs */
160 regmap_write(is31->regmap, IS31FL319X_DATA_UPDATE, 0x00);
161 /* enable chip from shut down */
162 ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x01);
163 } else {
164 dev_dbg(&is31->client->dev, "power down\n");
165 /* shut down (no need to clear CTRL1/2) */
166 ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x00);
167 }
168
169out:
170 mutex_unlock(&is31->lock);
171
172 return ret;
173}
174
175static int is31fl319x_parse_child_dt(const struct device *dev,
176 const struct device_node *child,
177 struct is31fl319x_led *led)
178{
179 struct led_classdev *cdev = &led->cdev;
180 int ret;
181
182 if (of_property_read_string(child, "label", &cdev->name))
183 cdev->name = child->name;
184
185 ret = of_property_read_string(child, "linux,default-trigger",
186 &cdev->default_trigger);
187 if (ret < 0 && ret != -EINVAL) /* is optional */
188 return ret;
189
190 led->max_microamp = IS31FL319X_CURRENT_DEFAULT;
191 ret = of_property_read_u32(child, "led-max-microamp",
192 &led->max_microamp);
193 if (!ret) {
194 if (led->max_microamp < IS31FL319X_CURRENT_MIN)
195 return -EINVAL; /* not supported */
196 led->max_microamp = min(led->max_microamp,
197 IS31FL319X_CURRENT_MAX);
198 }
199
200 return 0;
201}
202
203static int is31fl319x_parse_dt(struct device *dev,
204 struct is31fl319x_chip *is31)
205{
206 struct device_node *np = dev->of_node, *child;
207 const struct of_device_id *of_dev_id;
208 int count;
209 int ret;
210
211 if (!np)
212 return -ENODEV;
213
214 of_dev_id = of_match_device(of_is31fl319x_match, dev);
215 if (!of_dev_id) {
216 dev_err(dev, "Failed to match device with supported chips\n");
217 return -EINVAL;
218 }
219
220 is31->cdef = of_dev_id->data;
221
222 count = of_get_child_count(np);
223
224 dev_dbg(dev, "probe %s with %d leds defined in DT\n",
225 of_dev_id->compatible, count);
226
227 if (!count || count > is31->cdef->num_leds) {
228 dev_err(dev, "Number of leds defined must be between 1 and %u\n",
229 is31->cdef->num_leds);
230 return -ENODEV;
231 }
232
233 for_each_child_of_node(np, child) {
234 struct is31fl319x_led *led;
235 u32 reg;
236
237 ret = of_property_read_u32(child, "reg", ®);
238 if (ret) {
239 dev_err(dev, "Failed to read led 'reg' property\n");
240 goto put_child_node;
241 }
242
243 if (reg < 1 || reg > is31->cdef->num_leds) {
244 dev_err(dev, "invalid led reg %u\n", reg);
245 ret = -EINVAL;
246 goto put_child_node;
247 }
248
249 led = &is31->leds[reg - 1];
250
251 if (led->configured) {
252 dev_err(dev, "led %u is already configured\n", reg);
253 ret = -EINVAL;
254 goto put_child_node;
255 }
256
257 ret = is31fl319x_parse_child_dt(dev, child, led);
258 if (ret) {
259 dev_err(dev, "led %u DT parsing failed\n", reg);
260 goto put_child_node;
261 }
262
263 led->configured = true;
264 }
265
266 is31->audio_gain_db = 0;
267 ret = of_property_read_u32(np, "audio-gain-db", &is31->audio_gain_db);
268 if (!ret)
269 is31->audio_gain_db = min(is31->audio_gain_db,
270 IS31FL319X_AUDIO_GAIN_DB_MAX);
271
272 return 0;
273
274put_child_node:
275 of_node_put(child);
276 return ret;
277}
278
279static bool is31fl319x_readable_reg(struct device *dev, unsigned int reg)
280{ /* we have no readable registers */
281 return false;
282}
283
284static bool is31fl319x_volatile_reg(struct device *dev, unsigned int reg)
285{ /* volatile registers are not cached */
286 switch (reg) {
287 case IS31FL319X_DATA_UPDATE:
288 case IS31FL319X_TIME_UPDATE:
289 case IS31FL319X_RESET:
290 return true; /* always write-through */
291 default:
292 return false;
293 }
294}
295
296static const struct reg_default is31fl319x_reg_defaults[] = {
297 { IS31FL319X_CONFIG1, 0x00},
298 { IS31FL319X_CONFIG2, 0x00},
299 { IS31FL319X_PWM(0), 0x00},
300 { IS31FL319X_PWM(1), 0x00},
301 { IS31FL319X_PWM(2), 0x00},
302 { IS31FL319X_PWM(3), 0x00},
303 { IS31FL319X_PWM(4), 0x00},
304 { IS31FL319X_PWM(5), 0x00},
305 { IS31FL319X_PWM(6), 0x00},
306 { IS31FL319X_PWM(7), 0x00},
307 { IS31FL319X_PWM(8), 0x00},
308};
309
310static struct regmap_config regmap_config = {
311 .reg_bits = 8,
312 .val_bits = 8,
313 .max_register = IS31FL319X_REG_CNT,
314 .cache_type = REGCACHE_FLAT,
315 .readable_reg = is31fl319x_readable_reg,
316 .volatile_reg = is31fl319x_volatile_reg,
317 .reg_defaults = is31fl319x_reg_defaults,
318 .num_reg_defaults = ARRAY_SIZE(is31fl319x_reg_defaults),
319};
320
321static inline int is31fl319x_microamp_to_cs(struct device *dev, u32 microamp)
322{ /* round down to nearest supported value (range check done by caller) */
323 u32 step = microamp / IS31FL319X_CURRENT_STEP;
324
325 return ((IS31FL319X_CONFIG2_CS_STEP_REF - step) &
326 IS31FL319X_CONFIG2_CS_MASK) <<
327 IS31FL319X_CONFIG2_CS_SHIFT; /* CS encoding */
328}
329
330static inline int is31fl319x_db_to_gain(u32 dezibel)
331{ /* round down to nearest supported value (range check done by caller) */
332 return dezibel / IS31FL319X_AUDIO_GAIN_DB_STEP;
333}
334
335static int is31fl319x_probe(struct i2c_client *client,
336 const struct i2c_device_id *id)
337{
338 struct is31fl319x_chip *is31;
339 struct device *dev = &client->dev;
340 struct i2c_adapter *adapter = to_i2c_adapter(dev->parent);
341 int err;
342 int i = 0;
343 u32 aggregated_led_microamp = IS31FL319X_CURRENT_MAX;
344
345 if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
346 return -EIO;
347
348 is31 = devm_kzalloc(&client->dev, sizeof(*is31), GFP_KERNEL);
349 if (!is31)
350 return -ENOMEM;
351
352 mutex_init(&is31->lock);
353
354 err = is31fl319x_parse_dt(&client->dev, is31);
355 if (err)
356 goto free_mutex;
357
358 is31->client = client;
359 is31->regmap = devm_regmap_init_i2c(client, ®map_config);
360 if (IS_ERR(is31->regmap)) {
361 dev_err(&client->dev, "failed to allocate register map\n");
362 err = PTR_ERR(is31->regmap);
363 goto free_mutex;
364 }
365
366 i2c_set_clientdata(client, is31);
367
368 /* check for write-reply from chip (we can't read any registers) */
369 err = regmap_write(is31->regmap, IS31FL319X_RESET, 0x00);
370 if (err < 0) {
371 dev_err(&client->dev, "no response from chip write: err = %d\n",
372 err);
373 err = -EIO; /* does not answer */
374 goto free_mutex;
375 }
376
377 /*
378 * Kernel conventions require per-LED led-max-microamp property.
379 * But the chip does not allow to limit individual LEDs.
380 * So we take minimum from all subnodes for safety of hardware.
381 */
382 for (i = 0; i < is31->cdef->num_leds; i++)
383 if (is31->leds[i].configured &&
384 is31->leds[i].max_microamp < aggregated_led_microamp)
385 aggregated_led_microamp = is31->leds[i].max_microamp;
386
387 regmap_write(is31->regmap, IS31FL319X_CONFIG2,
388 is31fl319x_microamp_to_cs(dev, aggregated_led_microamp) |
389 is31fl319x_db_to_gain(is31->audio_gain_db));
390
391 for (i = 0; i < is31->cdef->num_leds; i++) {
392 struct is31fl319x_led *led = &is31->leds[i];
393
394 if (!led->configured)
395 continue;
396
397 led->chip = is31;
398 led->cdev.brightness_set_blocking = is31fl319x_brightness_set;
399
400 err = devm_led_classdev_register(&client->dev, &led->cdev);
401 if (err < 0)
402 goto free_mutex;
403 }
404
405 return 0;
406
407free_mutex:
408 mutex_destroy(&is31->lock);
409 return err;
410}
411
412static int is31fl319x_remove(struct i2c_client *client)
413{
414 struct is31fl319x_chip *is31 = i2c_get_clientdata(client);
415
416 mutex_destroy(&is31->lock);
417 return 0;
418}
419
420/*
421 * i2c-core (and modalias) requires that id_table be properly filled,
422 * even though it is not used for DeviceTree based instantiation.
423 */
424static const struct i2c_device_id is31fl319x_id[] = {
425 { "is31fl3190" },
426 { "is31fl3191" },
427 { "is31fl3193" },
428 { "is31fl3196" },
429 { "is31fl3199" },
430 { "sn3199" },
431 {},
432};
433MODULE_DEVICE_TABLE(i2c, is31fl319x_id);
434
435static struct i2c_driver is31fl319x_driver = {
436 .driver = {
437 .name = "leds-is31fl319x",
438 .of_match_table = of_match_ptr(of_is31fl319x_match),
439 },
440 .probe = is31fl319x_probe,
441 .remove = is31fl319x_remove,
442 .id_table = is31fl319x_id,
443};
444
445module_i2c_driver(is31fl319x_driver);
446
447MODULE_AUTHOR("H. Nikolaus Schaller <hns@goldelico.com>");
448MODULE_AUTHOR("Andrey Utkin <andrey_utkin@fastmail.com>");
449MODULE_DESCRIPTION("IS31FL319X LED driver");
450MODULE_LICENSE("GPL v2");