Merge branch '6.5/scsi-staging' into 6.5/scsi-fixes
[platform/kernel/linux-rpi.git] / drivers / leds / leds-lm3697.c
1 // SPDX-License-Identifier: GPL-2.0
2 // TI LM3697 LED chip family driver
3 // Copyright (C) 2018 Texas Instruments Incorporated - https://www.ti.com/
4
5 #include <linux/bits.h>
6 #include <linux/gpio/consumer.h>
7 #include <linux/i2c.h>
8 #include <linux/mod_devicetable.h>
9 #include <linux/module.h>
10 #include <linux/property.h>
11 #include <linux/regmap.h>
12 #include <linux/regulator/consumer.h>
13 #include <linux/types.h>
14
15 #include <linux/leds-ti-lmu-common.h>
16
17 #define LM3697_REV                      0x0
18 #define LM3697_RESET                    0x1
19 #define LM3697_OUTPUT_CONFIG            0x10
20 #define LM3697_CTRL_A_RAMP              0x11
21 #define LM3697_CTRL_B_RAMP              0x12
22 #define LM3697_CTRL_A_B_RT_RAMP         0x13
23 #define LM3697_CTRL_A_B_RAMP_CFG        0x14
24 #define LM3697_CTRL_A_B_BRT_CFG         0x16
25 #define LM3697_CTRL_A_FS_CURR_CFG       0x17
26 #define LM3697_CTRL_B_FS_CURR_CFG       0x18
27 #define LM3697_PWM_CFG                  0x1c
28 #define LM3697_CTRL_A_BRT_LSB           0x20
29 #define LM3697_CTRL_A_BRT_MSB           0x21
30 #define LM3697_CTRL_B_BRT_LSB           0x22
31 #define LM3697_CTRL_B_BRT_MSB           0x23
32 #define LM3697_CTRL_ENABLE              0x24
33
34 #define LM3697_SW_RESET         BIT(0)
35
36 #define LM3697_CTRL_A_EN        BIT(0)
37 #define LM3697_CTRL_B_EN        BIT(1)
38 #define LM3697_CTRL_A_B_EN      (LM3697_CTRL_A_EN | LM3697_CTRL_B_EN)
39
40 #define LM3697_MAX_LED_STRINGS  3
41
42 #define LM3697_CONTROL_A        0
43 #define LM3697_CONTROL_B        1
44 #define LM3697_MAX_CONTROL_BANKS 2
45
46 /**
47  * struct lm3697_led -
48  * @hvled_strings: Array of LED strings associated with a control bank
49  * @label: LED label
50  * @led_dev: LED class device
51  * @priv: Pointer to the device struct
52  * @lmu_data: Register and setting values for common code
53  * @control_bank: Control bank the LED is associated to. 0 is control bank A
54  *                 1 is control bank B
55  * @enabled: LED brightness level (or LED_OFF)
56  * @num_leds: Number of LEDs available
57  */
58 struct lm3697_led {
59         u32 hvled_strings[LM3697_MAX_LED_STRINGS];
60         char label[LED_MAX_NAME_SIZE];
61         struct led_classdev led_dev;
62         struct lm3697 *priv;
63         struct ti_lmu_bank lmu_data;
64         int control_bank;
65         int enabled;
66         int num_leds;
67 };
68
69 /**
70  * struct lm3697 -
71  * @enable_gpio: Hardware enable gpio
72  * @regulator: LED supply regulator pointer
73  * @client: Pointer to the I2C client
74  * @regmap: Devices register map
75  * @dev: Pointer to the devices device struct
76  * @lock: Lock for reading/writing the device
77  * @leds: Array of LED strings
78  * @bank_cfg: OUTPUT_CONFIG register values
79  * @num_banks: Number of control banks
80  */
81 struct lm3697 {
82         struct gpio_desc *enable_gpio;
83         struct regulator *regulator;
84         struct i2c_client *client;
85         struct regmap *regmap;
86         struct device *dev;
87         struct mutex lock;
88
89         int bank_cfg;
90         int num_banks;
91
92         struct lm3697_led leds[];
93 };
94
95 static const struct reg_default lm3697_reg_defs[] = {
96         {LM3697_OUTPUT_CONFIG, 0x6},
97         {LM3697_CTRL_A_RAMP, 0x0},
98         {LM3697_CTRL_B_RAMP, 0x0},
99         {LM3697_CTRL_A_B_RT_RAMP, 0x0},
100         {LM3697_CTRL_A_B_RAMP_CFG, 0x0},
101         {LM3697_CTRL_A_B_BRT_CFG, 0x0},
102         {LM3697_CTRL_A_FS_CURR_CFG, 0x13},
103         {LM3697_CTRL_B_FS_CURR_CFG, 0x13},
104         {LM3697_PWM_CFG, 0xc},
105         {LM3697_CTRL_A_BRT_LSB, 0x0},
106         {LM3697_CTRL_A_BRT_MSB, 0x0},
107         {LM3697_CTRL_B_BRT_LSB, 0x0},
108         {LM3697_CTRL_B_BRT_MSB, 0x0},
109         {LM3697_CTRL_ENABLE, 0x0},
110 };
111
112 static const struct regmap_config lm3697_regmap_config = {
113         .reg_bits = 8,
114         .val_bits = 8,
115
116         .max_register = LM3697_CTRL_ENABLE,
117         .reg_defaults = lm3697_reg_defs,
118         .num_reg_defaults = ARRAY_SIZE(lm3697_reg_defs),
119         .cache_type = REGCACHE_FLAT,
120 };
121
122 static int lm3697_brightness_set(struct led_classdev *led_cdev,
123                                 enum led_brightness brt_val)
124 {
125         struct lm3697_led *led = container_of(led_cdev, struct lm3697_led,
126                                               led_dev);
127         int ctrl_en_val = (1 << led->control_bank);
128         struct device *dev = led->priv->dev;
129         int ret;
130
131         mutex_lock(&led->priv->lock);
132
133         if (brt_val == LED_OFF) {
134                 ret = regmap_update_bits(led->priv->regmap, LM3697_CTRL_ENABLE,
135                                          ctrl_en_val, ~ctrl_en_val);
136                 if (ret) {
137                         dev_err(dev, "Cannot write ctrl register\n");
138                         goto brightness_out;
139                 }
140
141                 led->enabled = LED_OFF;
142         } else {
143                 ret = ti_lmu_common_set_brightness(&led->lmu_data, brt_val);
144                 if (ret) {
145                         dev_err(dev, "Cannot write brightness\n");
146                         goto brightness_out;
147                 }
148
149                 if (!led->enabled) {
150                         ret = regmap_update_bits(led->priv->regmap,
151                                                  LM3697_CTRL_ENABLE,
152                                                  ctrl_en_val, ctrl_en_val);
153                         if (ret) {
154                                 dev_err(dev, "Cannot enable the device\n");
155                                 goto brightness_out;
156                         }
157
158                         led->enabled = brt_val;
159                 }
160         }
161
162 brightness_out:
163         mutex_unlock(&led->priv->lock);
164         return ret;
165 }
166
167 static int lm3697_init(struct lm3697 *priv)
168 {
169         struct device *dev = priv->dev;
170         struct lm3697_led *led;
171         int i, ret;
172
173         if (priv->enable_gpio) {
174                 gpiod_direction_output(priv->enable_gpio, 1);
175         } else {
176                 ret = regmap_write(priv->regmap, LM3697_RESET, LM3697_SW_RESET);
177                 if (ret) {
178                         dev_err(dev, "Cannot reset the device\n");
179                         goto out;
180                 }
181         }
182
183         ret = regmap_write(priv->regmap, LM3697_CTRL_ENABLE, 0x0);
184         if (ret) {
185                 dev_err(dev, "Cannot write ctrl enable\n");
186                 goto out;
187         }
188
189         ret = regmap_write(priv->regmap, LM3697_OUTPUT_CONFIG, priv->bank_cfg);
190         if (ret)
191                 dev_err(dev, "Cannot write OUTPUT config\n");
192
193         for (i = 0; i < priv->num_banks; i++) {
194                 led = &priv->leds[i];
195                 ret = ti_lmu_common_set_ramp(&led->lmu_data);
196                 if (ret)
197                         dev_err(dev, "Setting the ramp rate failed\n");
198         }
199 out:
200         return ret;
201 }
202
203 static int lm3697_probe_dt(struct lm3697 *priv)
204 {
205         struct fwnode_handle *child = NULL;
206         struct device *dev = priv->dev;
207         struct lm3697_led *led;
208         int ret = -EINVAL;
209         int control_bank;
210         size_t i = 0;
211         int j;
212
213         priv->enable_gpio = devm_gpiod_get_optional(dev, "enable",
214                                                     GPIOD_OUT_LOW);
215         if (IS_ERR(priv->enable_gpio))
216                 return dev_err_probe(dev, PTR_ERR(priv->enable_gpio),
217                                           "Failed to get enable GPIO\n");
218
219         priv->regulator = devm_regulator_get(dev, "vled");
220         if (IS_ERR(priv->regulator))
221                 priv->regulator = NULL;
222
223         device_for_each_child_node(dev, child) {
224                 struct led_init_data init_data = {};
225
226                 ret = fwnode_property_read_u32(child, "reg", &control_bank);
227                 if (ret) {
228                         dev_err(dev, "reg property missing\n");
229                         goto child_out;
230                 }
231
232                 if (control_bank > LM3697_CONTROL_B) {
233                         dev_err(dev, "reg property is invalid\n");
234                         ret = -EINVAL;
235                         goto child_out;
236                 }
237
238                 led = &priv->leds[i];
239
240                 ret = ti_lmu_common_get_brt_res(dev, child, &led->lmu_data);
241                 if (ret)
242                         dev_warn(dev,
243                                  "brightness resolution property missing\n");
244
245                 led->control_bank = control_bank;
246                 led->lmu_data.regmap = priv->regmap;
247                 led->lmu_data.runtime_ramp_reg = LM3697_CTRL_A_RAMP +
248                                                  control_bank;
249                 led->lmu_data.msb_brightness_reg = LM3697_CTRL_A_BRT_MSB +
250                                                    led->control_bank * 2;
251                 led->lmu_data.lsb_brightness_reg = LM3697_CTRL_A_BRT_LSB +
252                                                    led->control_bank * 2;
253
254                 led->num_leds = fwnode_property_count_u32(child, "led-sources");
255                 if (led->num_leds > LM3697_MAX_LED_STRINGS) {
256                         dev_err(dev, "Too many LED strings defined\n");
257                         continue;
258                 }
259
260                 ret = fwnode_property_read_u32_array(child, "led-sources",
261                                                     led->hvled_strings,
262                                                     led->num_leds);
263                 if (ret) {
264                         dev_err(dev, "led-sources property missing\n");
265                         goto child_out;
266                 }
267
268                 for (j = 0; j < led->num_leds; j++)
269                         priv->bank_cfg |=
270                                 (led->control_bank << led->hvled_strings[j]);
271
272                 ret = ti_lmu_common_get_ramp_params(dev, child, &led->lmu_data);
273                 if (ret)
274                         dev_warn(dev, "runtime-ramp properties missing\n");
275
276                 init_data.fwnode = child;
277                 init_data.devicename = priv->client->name;
278                 /* for backwards compatibility if `label` is not present */
279                 init_data.default_label = ":";
280
281                 led->priv = priv;
282                 led->led_dev.max_brightness = led->lmu_data.max_brightness;
283                 led->led_dev.brightness_set_blocking = lm3697_brightness_set;
284
285                 ret = devm_led_classdev_register_ext(dev, &led->led_dev,
286                                                      &init_data);
287                 if (ret) {
288                         dev_err(dev, "led register err: %d\n", ret);
289                         goto child_out;
290                 }
291
292                 i++;
293         }
294
295         return ret;
296
297 child_out:
298         fwnode_handle_put(child);
299         return ret;
300 }
301
302 static int lm3697_probe(struct i2c_client *client)
303 {
304         struct device *dev = &client->dev;
305         struct lm3697 *led;
306         int count;
307         int ret;
308
309         count = device_get_child_node_count(dev);
310         if (!count || count > LM3697_MAX_CONTROL_BANKS) {
311                 dev_err(dev, "Strange device tree!");
312                 return -ENODEV;
313         }
314
315         led = devm_kzalloc(dev, struct_size(led, leds, count), GFP_KERNEL);
316         if (!led)
317                 return -ENOMEM;
318
319         mutex_init(&led->lock);
320         i2c_set_clientdata(client, led);
321
322         led->client = client;
323         led->dev = dev;
324         led->num_banks = count;
325         led->regmap = devm_regmap_init_i2c(client, &lm3697_regmap_config);
326         if (IS_ERR(led->regmap)) {
327                 ret = PTR_ERR(led->regmap);
328                 dev_err(dev, "Failed to allocate register map: %d\n", ret);
329                 return ret;
330         }
331
332         ret = lm3697_probe_dt(led);
333         if (ret)
334                 return ret;
335
336         return lm3697_init(led);
337 }
338
339 static void lm3697_remove(struct i2c_client *client)
340 {
341         struct lm3697 *led = i2c_get_clientdata(client);
342         struct device *dev = &led->client->dev;
343         int ret;
344
345         ret = regmap_update_bits(led->regmap, LM3697_CTRL_ENABLE,
346                                  LM3697_CTRL_A_B_EN, 0);
347         if (ret)
348                 dev_err(dev, "Failed to disable the device\n");
349
350         if (led->enable_gpio)
351                 gpiod_direction_output(led->enable_gpio, 0);
352
353         if (led->regulator) {
354                 ret = regulator_disable(led->regulator);
355                 if (ret)
356                         dev_err(dev, "Failed to disable regulator\n");
357         }
358
359         mutex_destroy(&led->lock);
360 }
361
362 static const struct i2c_device_id lm3697_id[] = {
363         { "lm3697", 0 },
364         { }
365 };
366 MODULE_DEVICE_TABLE(i2c, lm3697_id);
367
368 static const struct of_device_id of_lm3697_leds_match[] = {
369         { .compatible = "ti,lm3697", },
370         {},
371 };
372 MODULE_DEVICE_TABLE(of, of_lm3697_leds_match);
373
374 static struct i2c_driver lm3697_driver = {
375         .driver = {
376                 .name   = "lm3697",
377                 .of_match_table = of_lm3697_leds_match,
378         },
379         .probe          = lm3697_probe,
380         .remove         = lm3697_remove,
381         .id_table       = lm3697_id,
382 };
383 module_i2c_driver(lm3697_driver);
384
385 MODULE_DESCRIPTION("Texas Instruments LM3697 LED driver");
386 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
387 MODULE_LICENSE("GPL v2");