1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright 2011 bct electronic GmbH
4 * Copyright 2013 Qtechnology/AS
5 *
6 * Author: Peter Meerwald <p.meerwald@bct-electronic.com>
7 * Author: Ricardo Ribalda <ribalda@kernel.org>
8 *
9 * Based on leds-pca955x.c
10 *
11 * LED driver for the PCA9633 I2C LED driver (7-bit slave address 0x62)
12 * LED driver for the PCA9634/5 I2C LED driver (7-bit slave address set by hw.)
13 *
14 * Note that hardware blinking violates the leds infrastructure driver
15 * interface since the hardware only supports blinking all LEDs with the
16 * same delay_on/delay_off rates. That is, only the LEDs that are set to
17 * blink will actually blink but all LEDs that are set to blink will blink
18 * in identical fashion. The delay_on/delay_off values of the last LED
19 * that is set to blink will be used for all of the blinking LEDs.
20 * Hardware blinking is disabled by default but can be enabled by setting
21 * the 'blink_type' member in the platform_data struct to 'PCA963X_HW_BLINK'
22 * or by adding the 'nxp,hw-blink' property to the DTS.
23 */
24
25 #include <linux/module.h>
26 #include <linux/delay.h>
27 #include <linux/string.h>
28 #include <linux/ctype.h>
29 #include <linux/leds.h>
30 #include <linux/err.h>
31 #include <linux/i2c.h>
32 #include <linux/property.h>
33 #include <linux/slab.h>
34 #include <linux/of.h>
35
36 /* LED select registers determine the source that drives LED outputs */
37 #define PCA963X_LED_OFF 0x0 /* LED driver off */
38 #define PCA963X_LED_ON 0x1 /* LED driver on */
39 #define PCA963X_LED_PWM 0x2 /* Controlled through PWM */
40 #define PCA963X_LED_GRP_PWM 0x3 /* Controlled through PWM/GRPPWM */
41
42 #define PCA963X_MODE2_OUTDRV 0x04 /* Open-drain or totem pole */
43 #define PCA963X_MODE2_INVRT 0x10 /* Normal or inverted direction */
44 #define PCA963X_MODE2_DMBLNK 0x20 /* Enable blinking */
45
46 #define PCA963X_MODE1 0x00
47 #define PCA963X_MODE2 0x01
48 #define PCA963X_PWM_BASE 0x02
49
50 enum pca963x_type {
51 pca9633,
52 pca9634,
53 pca9635,
54 };
55
56 struct pca963x_chipdef {
57 u8 grppwm;
58 u8 grpfreq;
59 u8 ledout_base;
60 int n_leds;
61 unsigned int scaling;
62 };
63
64 static struct pca963x_chipdef pca963x_chipdefs[] = {
65 [pca9633] = {
66 .grppwm = 0x6,
67 .grpfreq = 0x7,
68 .ledout_base = 0x8,
69 .n_leds = 4,
70 },
71 [pca9634] = {
72 .grppwm = 0xa,
73 .grpfreq = 0xb,
74 .ledout_base = 0xc,
75 .n_leds = 8,
76 },
77 [pca9635] = {
78 .grppwm = 0x12,
79 .grpfreq = 0x13,
80 .ledout_base = 0x14,
81 .n_leds = 16,
82 },
83 };
84
85 /* Total blink period in milliseconds */
86 #define PCA963X_BLINK_PERIOD_MIN 42
87 #define PCA963X_BLINK_PERIOD_MAX 10667
88
89 static const struct i2c_device_id pca963x_id[] = {
90 { "pca9632", pca9633 },
91 { "pca9633", pca9633 },
92 { "pca9634", pca9634 },
93 { "pca9635", pca9635 },
94 { }
95 };
96 MODULE_DEVICE_TABLE(i2c, pca963x_id);
97
98 struct pca963x;
99
100 struct pca963x_led {
101 struct pca963x *chip;
102 struct led_classdev led_cdev;
103 int led_num; /* 0 .. 15 potentially */
104 bool blinking;
105 u8 gdc;
106 u8 gfrq;
107 };
108
109 struct pca963x {
110 struct pca963x_chipdef *chipdef;
111 struct mutex mutex;
112 struct i2c_client *client;
113 unsigned long leds_on;
114 struct pca963x_led leds[];
115 };
116
pca963x_brightness(struct pca963x_led * led,enum led_brightness brightness)117 static int pca963x_brightness(struct pca963x_led *led,
118 enum led_brightness brightness)
119 {
120 struct i2c_client *client = led->chip->client;
121 struct pca963x_chipdef *chipdef = led->chip->chipdef;
122 u8 ledout_addr, ledout, mask, val;
123 int shift;
124 int ret;
125
126 ledout_addr = chipdef->ledout_base + (led->led_num / 4);
127 shift = 2 * (led->led_num % 4);
128 mask = 0x3 << shift;
129 ledout = i2c_smbus_read_byte_data(client, ledout_addr);
130
131 switch (brightness) {
132 case LED_FULL:
133 if (led->blinking) {
134 val = (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift);
135 ret = i2c_smbus_write_byte_data(client,
136 PCA963X_PWM_BASE +
137 led->led_num,
138 LED_FULL);
139 } else {
140 val = (ledout & ~mask) | (PCA963X_LED_ON << shift);
141 }
142 ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
143 break;
144 case LED_OFF:
145 val = ledout & ~mask;
146 ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
147 led->blinking = false;
148 break;
149 default:
150 ret = i2c_smbus_write_byte_data(client,
151 PCA963X_PWM_BASE +
152 led->led_num,
153 brightness);
154 if (ret < 0)
155 return ret;
156
157 if (led->blinking)
158 val = (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift);
159 else
160 val = (ledout & ~mask) | (PCA963X_LED_PWM << shift);
161
162 ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
163 break;
164 }
165
166 return ret;
167 }
168
pca963x_blink(struct pca963x_led * led)169 static void pca963x_blink(struct pca963x_led *led)
170 {
171 struct i2c_client *client = led->chip->client;
172 struct pca963x_chipdef *chipdef = led->chip->chipdef;
173 u8 ledout_addr, ledout, mask, val, mode2;
174 int shift;
175
176 ledout_addr = chipdef->ledout_base + (led->led_num / 4);
177 shift = 2 * (led->led_num % 4);
178 mask = 0x3 << shift;
179 mode2 = i2c_smbus_read_byte_data(client, PCA963X_MODE2);
180
181 i2c_smbus_write_byte_data(client, chipdef->grppwm, led->gdc);
182
183 i2c_smbus_write_byte_data(client, chipdef->grpfreq, led->gfrq);
184
185 if (!(mode2 & PCA963X_MODE2_DMBLNK))
186 i2c_smbus_write_byte_data(client, PCA963X_MODE2,
187 mode2 | PCA963X_MODE2_DMBLNK);
188
189 mutex_lock(&led->chip->mutex);
190
191 ledout = i2c_smbus_read_byte_data(client, ledout_addr);
192 if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift)) {
193 val = (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift);
194 i2c_smbus_write_byte_data(client, ledout_addr, val);
195 }
196
197 mutex_unlock(&led->chip->mutex);
198 led->blinking = true;
199 }
200
pca963x_power_state(struct pca963x_led * led)201 static int pca963x_power_state(struct pca963x_led *led)
202 {
203 struct i2c_client *client = led->chip->client;
204 unsigned long *leds_on = &led->chip->leds_on;
205 unsigned long cached_leds = *leds_on;
206
207 if (led->led_cdev.brightness)
208 set_bit(led->led_num, leds_on);
209 else
210 clear_bit(led->led_num, leds_on);
211
212 if (!(*leds_on) != !cached_leds)
213 return i2c_smbus_write_byte_data(client, PCA963X_MODE1,
214 *leds_on ? 0 : BIT(4));
215
216 return 0;
217 }
218
pca963x_led_set(struct led_classdev * led_cdev,enum led_brightness value)219 static int pca963x_led_set(struct led_classdev *led_cdev,
220 enum led_brightness value)
221 {
222 struct pca963x_led *led;
223 int ret;
224
225 led = container_of(led_cdev, struct pca963x_led, led_cdev);
226
227 mutex_lock(&led->chip->mutex);
228
229 ret = pca963x_brightness(led, value);
230 if (ret < 0)
231 goto unlock;
232 ret = pca963x_power_state(led);
233
234 unlock:
235 mutex_unlock(&led->chip->mutex);
236 return ret;
237 }
238
pca963x_period_scale(struct pca963x_led * led,unsigned int val)239 static unsigned int pca963x_period_scale(struct pca963x_led *led,
240 unsigned int val)
241 {
242 unsigned int scaling = led->chip->chipdef->scaling;
243
244 return scaling ? DIV_ROUND_CLOSEST(val * scaling, 1000) : val;
245 }
246
pca963x_blink_set(struct led_classdev * led_cdev,unsigned long * delay_on,unsigned long * delay_off)247 static int pca963x_blink_set(struct led_classdev *led_cdev,
248 unsigned long *delay_on, unsigned long *delay_off)
249 {
250 unsigned long time_on, time_off, period;
251 struct pca963x_led *led;
252 u8 gdc, gfrq;
253
254 led = container_of(led_cdev, struct pca963x_led, led_cdev);
255
256 time_on = *delay_on;
257 time_off = *delay_off;
258
259 /* If both zero, pick reasonable defaults of 500ms each */
260 if (!time_on && !time_off) {
261 time_on = 500;
262 time_off = 500;
263 }
264
265 period = pca963x_period_scale(led, time_on + time_off);
266
267 /* If period not supported by hardware, default to someting sane. */
268 if ((period < PCA963X_BLINK_PERIOD_MIN) ||
269 (period > PCA963X_BLINK_PERIOD_MAX)) {
270 time_on = 500;
271 time_off = 500;
272 period = pca963x_period_scale(led, 1000);
273 }
274
275 /*
276 * From manual: duty cycle = (GDC / 256) ->
277 * (time_on / period) = (GDC / 256) ->
278 * GDC = ((time_on * 256) / period)
279 */
280 gdc = (pca963x_period_scale(led, time_on) * 256) / period;
281
282 /*
283 * From manual: period = ((GFRQ + 1) / 24) in seconds.
284 * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
285 * GFRQ = ((period * 24 / 1000) - 1)
286 */
287 gfrq = (period * 24 / 1000) - 1;
288
289 led->gdc = gdc;
290 led->gfrq = gfrq;
291
292 pca963x_blink(led);
293 led->led_cdev.brightness = LED_FULL;
294 pca963x_led_set(led_cdev, LED_FULL);
295
296 *delay_on = time_on;
297 *delay_off = time_off;
298
299 return 0;
300 }
301
pca963x_register_leds(struct i2c_client * client,struct pca963x * chip)302 static int pca963x_register_leds(struct i2c_client *client,
303 struct pca963x *chip)
304 {
305 struct pca963x_chipdef *chipdef = chip->chipdef;
306 struct pca963x_led *led = chip->leds;
307 struct device *dev = &client->dev;
308 struct fwnode_handle *child;
309 bool hw_blink;
310 s32 mode2;
311 u32 reg;
312 int ret;
313
314 if (device_property_read_u32(dev, "nxp,period-scale",
315 &chipdef->scaling))
316 chipdef->scaling = 1000;
317
318 hw_blink = device_property_read_bool(dev, "nxp,hw-blink");
319
320 mode2 = i2c_smbus_read_byte_data(client, PCA963X_MODE2);
321 if (mode2 < 0)
322 return mode2;
323
324 /* default to open-drain unless totem pole (push-pull) is specified */
325 if (device_property_read_bool(dev, "nxp,totem-pole"))
326 mode2 |= PCA963X_MODE2_OUTDRV;
327 else
328 mode2 &= ~PCA963X_MODE2_OUTDRV;
329
330 /* default to non-inverted output, unless inverted is specified */
331 if (device_property_read_bool(dev, "nxp,inverted-out"))
332 mode2 |= PCA963X_MODE2_INVRT;
333 else
334 mode2 &= ~PCA963X_MODE2_INVRT;
335
336 ret = i2c_smbus_write_byte_data(client, PCA963X_MODE2, mode2);
337 if (ret < 0)
338 return ret;
339
340 device_for_each_child_node(dev, child) {
341 struct led_init_data init_data = {};
342 char default_label[32];
343
344 ret = fwnode_property_read_u32(child, "reg", ®);
345 if (ret || reg >= chipdef->n_leds) {
346 dev_err(dev, "Invalid 'reg' property for node %pfw\n",
347 child);
348 ret = -EINVAL;
349 goto err;
350 }
351
352 led->led_num = reg;
353 led->chip = chip;
354 led->led_cdev.brightness_set_blocking = pca963x_led_set;
355 if (hw_blink)
356 led->led_cdev.blink_set = pca963x_blink_set;
357 led->blinking = false;
358
359 init_data.fwnode = child;
360 /* for backwards compatibility */
361 init_data.devicename = "pca963x";
362 snprintf(default_label, sizeof(default_label), "%d:%.2x:%u",
363 client->adapter->nr, client->addr, reg);
364 init_data.default_label = default_label;
365
366 ret = devm_led_classdev_register_ext(dev, &led->led_cdev,
367 &init_data);
368 if (ret) {
369 dev_err(dev, "Failed to register LED for node %pfw\n",
370 child);
371 goto err;
372 }
373
374 ++led;
375 }
376
377 return 0;
378 err:
379 fwnode_handle_put(child);
380 return ret;
381 }
382
383 static const struct of_device_id of_pca963x_match[] = {
384 { .compatible = "nxp,pca9632", },
385 { .compatible = "nxp,pca9633", },
386 { .compatible = "nxp,pca9634", },
387 { .compatible = "nxp,pca9635", },
388 {},
389 };
390 MODULE_DEVICE_TABLE(of, of_pca963x_match);
391
pca963x_probe(struct i2c_client * client,const struct i2c_device_id * id)392 static int pca963x_probe(struct i2c_client *client,
393 const struct i2c_device_id *id)
394 {
395 struct device *dev = &client->dev;
396 struct pca963x_chipdef *chipdef;
397 struct pca963x *chip;
398 int i, count;
399
400 chipdef = &pca963x_chipdefs[id->driver_data];
401
402 count = device_get_child_node_count(dev);
403 if (!count || count > chipdef->n_leds) {
404 dev_err(dev, "Node %pfw must define between 1 and %d LEDs\n",
405 dev_fwnode(dev), chipdef->n_leds);
406 return -EINVAL;
407 }
408
409 chip = devm_kzalloc(dev, struct_size(chip, leds, count), GFP_KERNEL);
410 if (!chip)
411 return -ENOMEM;
412
413 i2c_set_clientdata(client, chip);
414
415 mutex_init(&chip->mutex);
416 chip->chipdef = chipdef;
417 chip->client = client;
418
419 /* Turn off LEDs by default*/
420 for (i = 0; i < chipdef->n_leds / 4; i++)
421 i2c_smbus_write_byte_data(client, chipdef->ledout_base + i, 0x00);
422
423 /* Disable LED all-call address, and power down initially */
424 i2c_smbus_write_byte_data(client, PCA963X_MODE1, BIT(4));
425
426 return pca963x_register_leds(client, chip);
427 }
428
429 static struct i2c_driver pca963x_driver = {
430 .driver = {
431 .name = "leds-pca963x",
432 .of_match_table = of_pca963x_match,
433 },
434 .probe = pca963x_probe,
435 .id_table = pca963x_id,
436 };
437
438 module_i2c_driver(pca963x_driver);
439
440 MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
441 MODULE_DESCRIPTION("PCA963X LED driver");
442 MODULE_LICENSE("GPL v2");
443