1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Driver for ISSI IS31FL32xx family of I2C LED controllers
4 *
5 * Copyright 2015 Allworx Corp.
6 *
7 * Datasheets:
8 * http://www.issi.com/US/product-analog-fxled-driver.shtml
9 * http://www.si-en.com/product.asp?parentid=890
10 */
11
12 #include <linux/device.h>
13 #include <linux/i2c.h>
14 #include <linux/kernel.h>
15 #include <linux/leds.h>
16 #include <linux/module.h>
17 #include <linux/of.h>
18
19 /* Used to indicate a device has no such register */
20 #define IS31FL32XX_REG_NONE 0xFF
21
22 /* Software Shutdown bit in Shutdown Register */
23 #define IS31FL32XX_SHUTDOWN_SSD_ENABLE 0
24 #define IS31FL32XX_SHUTDOWN_SSD_DISABLE BIT(0)
25
26 /* IS31FL3216 has a number of unique registers */
27 #define IS31FL3216_CONFIG_REG 0x00
28 #define IS31FL3216_LIGHTING_EFFECT_REG 0x03
29 #define IS31FL3216_CHANNEL_CONFIG_REG 0x04
30
31 /* Software Shutdown bit in 3216 Config Register */
32 #define IS31FL3216_CONFIG_SSD_ENABLE BIT(7)
33 #define IS31FL3216_CONFIG_SSD_DISABLE 0
34
35 struct is31fl32xx_priv;
36 struct is31fl32xx_led_data {
37 struct led_classdev cdev;
38 u8 channel; /* 1-based, max priv->cdef->channels */
39 struct is31fl32xx_priv *priv;
40 };
41
42 struct is31fl32xx_priv {
43 const struct is31fl32xx_chipdef *cdef;
44 struct i2c_client *client;
45 unsigned int num_leds;
46 struct is31fl32xx_led_data leds[];
47 };
48
49 /**
50 * struct is31fl32xx_chipdef - chip-specific attributes
51 * @channels : Number of LED channels
52 * @shutdown_reg : address of Shutdown register (optional)
53 * @pwm_update_reg : address of PWM Update register
54 * @global_control_reg : address of Global Control register (optional)
55 * @reset_reg : address of Reset register (optional)
56 * @pwm_register_base : address of first PWM register
57 * @pwm_registers_reversed: : true if PWM registers count down instead of up
58 * @led_control_register_base : address of first LED control register (optional)
59 * @enable_bits_per_led_control_register: number of LEDs enable bits in each
60 * @reset_func : pointer to reset function
61 * @sw_shutdown_func : pointer to software shutdown function
62 *
63 * For all optional register addresses, the sentinel value %IS31FL32XX_REG_NONE
64 * indicates that this chip has no such register.
65 *
66 * If non-NULL, @reset_func will be called during probing to set all
67 * necessary registers to a known initialization state. This is needed
68 * for chips that do not have a @reset_reg.
69 *
70 * @enable_bits_per_led_control_register must be >=1 if
71 * @led_control_register_base != %IS31FL32XX_REG_NONE.
72 */
73 struct is31fl32xx_chipdef {
74 u8 channels;
75 u8 shutdown_reg;
76 u8 pwm_update_reg;
77 u8 global_control_reg;
78 u8 reset_reg;
79 u8 pwm_register_base;
80 bool pwm_registers_reversed;
81 u8 led_control_register_base;
82 u8 enable_bits_per_led_control_register;
83 int (*reset_func)(struct is31fl32xx_priv *priv);
84 int (*sw_shutdown_func)(struct is31fl32xx_priv *priv, bool enable);
85 };
86
87 static const struct is31fl32xx_chipdef is31fl3236_cdef = {
88 .channels = 36,
89 .shutdown_reg = 0x00,
90 .pwm_update_reg = 0x25,
91 .global_control_reg = 0x4a,
92 .reset_reg = 0x4f,
93 .pwm_register_base = 0x01,
94 .led_control_register_base = 0x26,
95 .enable_bits_per_led_control_register = 1,
96 };
97
98 static const struct is31fl32xx_chipdef is31fl3235_cdef = {
99 .channels = 28,
100 .shutdown_reg = 0x00,
101 .pwm_update_reg = 0x25,
102 .global_control_reg = 0x4a,
103 .reset_reg = 0x4f,
104 .pwm_register_base = 0x05,
105 .led_control_register_base = 0x2a,
106 .enable_bits_per_led_control_register = 1,
107 };
108
109 static const struct is31fl32xx_chipdef is31fl3218_cdef = {
110 .channels = 18,
111 .shutdown_reg = 0x00,
112 .pwm_update_reg = 0x16,
113 .global_control_reg = IS31FL32XX_REG_NONE,
114 .reset_reg = 0x17,
115 .pwm_register_base = 0x01,
116 .led_control_register_base = 0x13,
117 .enable_bits_per_led_control_register = 6,
118 };
119
120 static int is31fl3216_reset(struct is31fl32xx_priv *priv);
121 static int is31fl3216_software_shutdown(struct is31fl32xx_priv *priv,
122 bool enable);
123 static const struct is31fl32xx_chipdef is31fl3216_cdef = {
124 .channels = 16,
125 .shutdown_reg = IS31FL32XX_REG_NONE,
126 .pwm_update_reg = 0xB0,
127 .global_control_reg = IS31FL32XX_REG_NONE,
128 .reset_reg = IS31FL32XX_REG_NONE,
129 .pwm_register_base = 0x10,
130 .pwm_registers_reversed = true,
131 .led_control_register_base = 0x01,
132 .enable_bits_per_led_control_register = 8,
133 .reset_func = is31fl3216_reset,
134 .sw_shutdown_func = is31fl3216_software_shutdown,
135 };
136
is31fl32xx_write(struct is31fl32xx_priv * priv,u8 reg,u8 val)137 static int is31fl32xx_write(struct is31fl32xx_priv *priv, u8 reg, u8 val)
138 {
139 int ret;
140
141 dev_dbg(&priv->client->dev, "writing register 0x%02X=0x%02X", reg, val);
142
143 ret = i2c_smbus_write_byte_data(priv->client, reg, val);
144 if (ret) {
145 dev_err(&priv->client->dev,
146 "register write to 0x%02X failed (error %d)",
147 reg, ret);
148 }
149 return ret;
150 }
151
152 /*
153 * Custom reset function for IS31FL3216 because it does not have a RESET
154 * register the way that the other IS31FL32xx chips do. We don't bother
155 * writing the GPIO and animation registers, because the registers we
156 * do write ensure those will have no effect.
157 */
is31fl3216_reset(struct is31fl32xx_priv * priv)158 static int is31fl3216_reset(struct is31fl32xx_priv *priv)
159 {
160 unsigned int i;
161 int ret;
162
163 ret = is31fl32xx_write(priv, IS31FL3216_CONFIG_REG,
164 IS31FL3216_CONFIG_SSD_ENABLE);
165 if (ret)
166 return ret;
167 for (i = 0; i < priv->cdef->channels; i++) {
168 ret = is31fl32xx_write(priv, priv->cdef->pwm_register_base+i,
169 0x00);
170 if (ret)
171 return ret;
172 }
173 ret = is31fl32xx_write(priv, priv->cdef->pwm_update_reg, 0);
174 if (ret)
175 return ret;
176 ret = is31fl32xx_write(priv, IS31FL3216_LIGHTING_EFFECT_REG, 0x00);
177 if (ret)
178 return ret;
179 ret = is31fl32xx_write(priv, IS31FL3216_CHANNEL_CONFIG_REG, 0x00);
180 if (ret)
181 return ret;
182
183 return 0;
184 }
185
186 /*
187 * Custom Software-Shutdown function for IS31FL3216 because it does not have
188 * a SHUTDOWN register the way that the other IS31FL32xx chips do.
189 * We don't bother doing a read/modify/write on the CONFIG register because
190 * we only ever use a value of '0' for the other fields in that register.
191 */
is31fl3216_software_shutdown(struct is31fl32xx_priv * priv,bool enable)192 static int is31fl3216_software_shutdown(struct is31fl32xx_priv *priv,
193 bool enable)
194 {
195 u8 value = enable ? IS31FL3216_CONFIG_SSD_ENABLE :
196 IS31FL3216_CONFIG_SSD_DISABLE;
197
198 return is31fl32xx_write(priv, IS31FL3216_CONFIG_REG, value);
199 }
200
201 /*
202 * NOTE: A mutex is not needed in this function because:
203 * - All referenced data is read-only after probe()
204 * - The I2C core has a mutex on to protect the bus
205 * - There are no read/modify/write operations
206 * - Intervening operations between the write of the PWM register
207 * and the Update register are harmless.
208 *
209 * Example:
210 * PWM_REG_1 write 16
211 * UPDATE_REG write 0
212 * PWM_REG_2 write 128
213 * UPDATE_REG write 0
214 * vs:
215 * PWM_REG_1 write 16
216 * PWM_REG_2 write 128
217 * UPDATE_REG write 0
218 * UPDATE_REG write 0
219 * are equivalent. Poking the Update register merely applies all PWM
220 * register writes up to that point.
221 */
is31fl32xx_brightness_set(struct led_classdev * led_cdev,enum led_brightness brightness)222 static int is31fl32xx_brightness_set(struct led_classdev *led_cdev,
223 enum led_brightness brightness)
224 {
225 const struct is31fl32xx_led_data *led_data =
226 container_of(led_cdev, struct is31fl32xx_led_data, cdev);
227 const struct is31fl32xx_chipdef *cdef = led_data->priv->cdef;
228 u8 pwm_register_offset;
229 int ret;
230
231 dev_dbg(led_cdev->dev, "%s: %d\n", __func__, brightness);
232
233 /* NOTE: led_data->channel is 1-based */
234 if (cdef->pwm_registers_reversed)
235 pwm_register_offset = cdef->channels - led_data->channel;
236 else
237 pwm_register_offset = led_data->channel - 1;
238
239 ret = is31fl32xx_write(led_data->priv,
240 cdef->pwm_register_base + pwm_register_offset,
241 brightness);
242 if (ret)
243 return ret;
244
245 return is31fl32xx_write(led_data->priv, cdef->pwm_update_reg, 0);
246 }
247
is31fl32xx_reset_regs(struct is31fl32xx_priv * priv)248 static int is31fl32xx_reset_regs(struct is31fl32xx_priv *priv)
249 {
250 const struct is31fl32xx_chipdef *cdef = priv->cdef;
251 int ret;
252
253 if (cdef->reset_reg != IS31FL32XX_REG_NONE) {
254 ret = is31fl32xx_write(priv, cdef->reset_reg, 0);
255 if (ret)
256 return ret;
257 }
258
259 if (cdef->reset_func)
260 return cdef->reset_func(priv);
261
262 return 0;
263 }
264
is31fl32xx_software_shutdown(struct is31fl32xx_priv * priv,bool enable)265 static int is31fl32xx_software_shutdown(struct is31fl32xx_priv *priv,
266 bool enable)
267 {
268 const struct is31fl32xx_chipdef *cdef = priv->cdef;
269 int ret;
270
271 if (cdef->shutdown_reg != IS31FL32XX_REG_NONE) {
272 u8 value = enable ? IS31FL32XX_SHUTDOWN_SSD_ENABLE :
273 IS31FL32XX_SHUTDOWN_SSD_DISABLE;
274 ret = is31fl32xx_write(priv, cdef->shutdown_reg, value);
275 if (ret)
276 return ret;
277 }
278
279 if (cdef->sw_shutdown_func)
280 return cdef->sw_shutdown_func(priv, enable);
281
282 return 0;
283 }
284
is31fl32xx_init_regs(struct is31fl32xx_priv * priv)285 static int is31fl32xx_init_regs(struct is31fl32xx_priv *priv)
286 {
287 const struct is31fl32xx_chipdef *cdef = priv->cdef;
288 int ret;
289
290 ret = is31fl32xx_reset_regs(priv);
291 if (ret)
292 return ret;
293
294 /*
295 * Set enable bit for all channels.
296 * We will control state with PWM registers alone.
297 */
298 if (cdef->led_control_register_base != IS31FL32XX_REG_NONE) {
299 u8 value =
300 GENMASK(cdef->enable_bits_per_led_control_register-1, 0);
301 u8 num_regs = cdef->channels /
302 cdef->enable_bits_per_led_control_register;
303 int i;
304
305 for (i = 0; i < num_regs; i++) {
306 ret = is31fl32xx_write(priv,
307 cdef->led_control_register_base+i,
308 value);
309 if (ret)
310 return ret;
311 }
312 }
313
314 ret = is31fl32xx_software_shutdown(priv, false);
315 if (ret)
316 return ret;
317
318 if (cdef->global_control_reg != IS31FL32XX_REG_NONE) {
319 ret = is31fl32xx_write(priv, cdef->global_control_reg, 0x00);
320 if (ret)
321 return ret;
322 }
323
324 return 0;
325 }
326
is31fl32xx_parse_child_dt(const struct device * dev,const struct device_node * child,struct is31fl32xx_led_data * led_data)327 static int is31fl32xx_parse_child_dt(const struct device *dev,
328 const struct device_node *child,
329 struct is31fl32xx_led_data *led_data)
330 {
331 struct led_classdev *cdev = &led_data->cdev;
332 int ret = 0;
333 u32 reg;
334
335 ret = of_property_read_u32(child, "reg", ®);
336 if (ret || reg < 1 || reg > led_data->priv->cdef->channels) {
337 dev_err(dev,
338 "Child node %pOF does not have a valid reg property\n",
339 child);
340 return -EINVAL;
341 }
342 led_data->channel = reg;
343
344 cdev->brightness_set_blocking = is31fl32xx_brightness_set;
345
346 return 0;
347 }
348
is31fl32xx_find_led_data(struct is31fl32xx_priv * priv,u8 channel)349 static struct is31fl32xx_led_data *is31fl32xx_find_led_data(
350 struct is31fl32xx_priv *priv,
351 u8 channel)
352 {
353 size_t i;
354
355 for (i = 0; i < priv->num_leds; i++) {
356 if (priv->leds[i].channel == channel)
357 return &priv->leds[i];
358 }
359
360 return NULL;
361 }
362
is31fl32xx_parse_dt(struct device * dev,struct is31fl32xx_priv * priv)363 static int is31fl32xx_parse_dt(struct device *dev,
364 struct is31fl32xx_priv *priv)
365 {
366 struct device_node *child;
367 int ret = 0;
368
369 for_each_available_child_of_node(dev_of_node(dev), child) {
370 struct led_init_data init_data = {};
371 struct is31fl32xx_led_data *led_data =
372 &priv->leds[priv->num_leds];
373 const struct is31fl32xx_led_data *other_led_data;
374
375 led_data->priv = priv;
376
377 ret = is31fl32xx_parse_child_dt(dev, child, led_data);
378 if (ret)
379 goto err;
380
381 /* Detect if channel is already in use by another child */
382 other_led_data = is31fl32xx_find_led_data(priv,
383 led_data->channel);
384 if (other_led_data) {
385 dev_err(dev,
386 "Node %pOF 'reg' conflicts with another LED\n",
387 child);
388 ret = -EINVAL;
389 goto err;
390 }
391
392 init_data.fwnode = of_fwnode_handle(child);
393
394 ret = devm_led_classdev_register_ext(dev, &led_data->cdev,
395 &init_data);
396 if (ret) {
397 dev_err(dev, "Failed to register LED for %pOF: %d\n",
398 child, ret);
399 goto err;
400 }
401
402 priv->num_leds++;
403 }
404
405 return 0;
406
407 err:
408 of_node_put(child);
409 return ret;
410 }
411
412 static const struct of_device_id of_is31fl32xx_match[] = {
413 { .compatible = "issi,is31fl3236", .data = &is31fl3236_cdef, },
414 { .compatible = "issi,is31fl3235", .data = &is31fl3235_cdef, },
415 { .compatible = "issi,is31fl3218", .data = &is31fl3218_cdef, },
416 { .compatible = "si-en,sn3218", .data = &is31fl3218_cdef, },
417 { .compatible = "issi,is31fl3216", .data = &is31fl3216_cdef, },
418 { .compatible = "si-en,sn3216", .data = &is31fl3216_cdef, },
419 {},
420 };
421
422 MODULE_DEVICE_TABLE(of, of_is31fl32xx_match);
423
is31fl32xx_probe(struct i2c_client * client)424 static int is31fl32xx_probe(struct i2c_client *client)
425 {
426 const struct is31fl32xx_chipdef *cdef;
427 struct device *dev = &client->dev;
428 struct is31fl32xx_priv *priv;
429 int count;
430 int ret = 0;
431
432 cdef = device_get_match_data(dev);
433
434 count = of_get_available_child_count(dev_of_node(dev));
435 if (!count)
436 return -EINVAL;
437
438 priv = devm_kzalloc(dev, struct_size(priv, leds, count),
439 GFP_KERNEL);
440 if (!priv)
441 return -ENOMEM;
442
443 priv->client = client;
444 priv->cdef = cdef;
445 i2c_set_clientdata(client, priv);
446
447 ret = is31fl32xx_init_regs(priv);
448 if (ret)
449 return ret;
450
451 ret = is31fl32xx_parse_dt(dev, priv);
452 if (ret)
453 return ret;
454
455 return 0;
456 }
457
is31fl32xx_remove(struct i2c_client * client)458 static void is31fl32xx_remove(struct i2c_client *client)
459 {
460 struct is31fl32xx_priv *priv = i2c_get_clientdata(client);
461 int ret;
462
463 ret = is31fl32xx_reset_regs(priv);
464 if (ret)
465 dev_err(&client->dev, "Failed to reset registers on removal (%pe)\n",
466 ERR_PTR(ret));
467 }
468
469 /*
470 * i2c-core (and modalias) requires that id_table be properly filled,
471 * even though it is not used for DeviceTree based instantiation.
472 */
473 static const struct i2c_device_id is31fl32xx_id[] = {
474 { "is31fl3236" },
475 { "is31fl3235" },
476 { "is31fl3218" },
477 { "sn3218" },
478 { "is31fl3216" },
479 { "sn3216" },
480 {},
481 };
482
483 MODULE_DEVICE_TABLE(i2c, is31fl32xx_id);
484
485 static struct i2c_driver is31fl32xx_driver = {
486 .driver = {
487 .name = "is31fl32xx",
488 .of_match_table = of_is31fl32xx_match,
489 },
490 .probe = is31fl32xx_probe,
491 .remove = is31fl32xx_remove,
492 .id_table = is31fl32xx_id,
493 };
494
495 module_i2c_driver(is31fl32xx_driver);
496
497 MODULE_AUTHOR("David Rivshin <drivshin@allworx.com>");
498 MODULE_DESCRIPTION("ISSI IS31FL32xx LED driver");
499 MODULE_LICENSE("GPL v2");
500