1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * LED driver for TI lp3952 controller
4 *
5 * Copyright (C) 2016, DAQRI, LLC.
6 * Author: Tony Makkiel <tony.makkiel@daqri.com>
7 */
8
9#include <linux/delay.h>
10#include <linux/gpio/consumer.h>
11#include <linux/i2c.h>
12#include <linux/io.h>
13#include <linux/kernel.h>
14#include <linux/leds.h>
15#include <linux/leds-lp3952.h>
16#include <linux/module.h>
17#include <linux/notifier.h>
18#include <linux/platform_device.h>
19#include <linux/pm.h>
20#include <linux/reboot.h>
21#include <linux/regmap.h>
22
23static int lp3952_register_write(struct i2c_client *client, u8 reg, u8 val)
24{
25 int ret;
26 struct lp3952_led_array *priv = i2c_get_clientdata(client);
27
28 ret = regmap_write(map: priv->regmap, reg, val);
29
30 if (ret)
31 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
32 __func__, reg, val, ret);
33 return ret;
34}
35
36static void lp3952_on_off(struct lp3952_led_array *priv,
37 enum lp3952_leds led_id, bool on)
38{
39 int ret, val;
40
41 dev_dbg(&priv->client->dev, "%s LED %d to %d\n", __func__, led_id, on);
42
43 val = 1 << led_id;
44 if (led_id == LP3952_LED_ALL)
45 val = LP3952_LED_MASK_ALL;
46
47 ret = regmap_update_bits(map: priv->regmap, LP3952_REG_LED_CTRL, mask: val,
48 val: on ? val : 0);
49 if (ret)
50 dev_err(&priv->client->dev, "%s, Error %d\n", __func__, ret);
51}
52
53/*
54 * Using Imax to control brightness. There are 4 possible
55 * setting 25, 50, 75 and 100 % of Imax. Possible values are
56 * values 0-4. 0 meaning turn off.
57 */
58static int lp3952_set_brightness(struct led_classdev *cdev,
59 enum led_brightness value)
60{
61 unsigned int reg, shift_val;
62 struct lp3952_ctrl_hdl *led = container_of(cdev,
63 struct lp3952_ctrl_hdl,
64 cdev);
65 struct lp3952_led_array *priv = (struct lp3952_led_array *)led->priv;
66
67 dev_dbg(cdev->dev, "Brightness request: %d on %d\n", value,
68 led->channel);
69
70 if (value == LED_OFF) {
71 lp3952_on_off(priv, led_id: led->channel, on: false);
72 return 0;
73 }
74
75 if (led->channel > LP3952_RED_1) {
76 dev_err(cdev->dev, " %s Invalid LED requested", __func__);
77 return -EINVAL;
78 }
79
80 if (led->channel >= LP3952_BLUE_1) {
81 reg = LP3952_REG_RGB1_MAX_I_CTRL;
82 shift_val = (led->channel - LP3952_BLUE_1) * 2;
83 } else {
84 reg = LP3952_REG_RGB2_MAX_I_CTRL;
85 shift_val = led->channel * 2;
86 }
87
88 /* Enable the LED in case it is not enabled already */
89 lp3952_on_off(priv, led_id: led->channel, on: true);
90
91 return regmap_update_bits(map: priv->regmap, reg, mask: 3 << shift_val,
92 val: --value << shift_val);
93}
94
95static int lp3952_get_label(struct device *dev, const char *label, char *dest)
96{
97 int ret;
98 const char *str;
99
100 ret = device_property_read_string(dev, propname: label, val: &str);
101 if (ret)
102 return ret;
103
104 strscpy(dest, str, LP3952_LABEL_MAX_LEN);
105 return 0;
106}
107
108static int lp3952_register_led_classdev(struct lp3952_led_array *priv)
109{
110 int i, acpi_ret, ret = -ENODEV;
111 static const char *led_name_hdl[LP3952_LED_ALL] = {
112 "blue2",
113 "green2",
114 "red2",
115 "blue1",
116 "green1",
117 "red1"
118 };
119
120 for (i = 0; i < LP3952_LED_ALL; i++) {
121 acpi_ret = lp3952_get_label(dev: &priv->client->dev, label: led_name_hdl[i],
122 dest: priv->leds[i].name);
123 if (acpi_ret)
124 continue;
125
126 priv->leds[i].cdev.name = priv->leds[i].name;
127 priv->leds[i].cdev.brightness = LED_OFF;
128 priv->leds[i].cdev.max_brightness = LP3952_BRIGHT_MAX;
129 priv->leds[i].cdev.brightness_set_blocking =
130 lp3952_set_brightness;
131 priv->leds[i].channel = i;
132 priv->leds[i].priv = priv;
133
134 ret = devm_led_classdev_register(parent: &priv->client->dev,
135 led_cdev: &priv->leds[i].cdev);
136 if (ret < 0) {
137 dev_err(&priv->client->dev,
138 "couldn't register LED %s\n",
139 priv->leds[i].cdev.name);
140 break;
141 }
142 }
143 return ret;
144}
145
146static int lp3952_set_pattern_gen_cmd(struct lp3952_led_array *priv,
147 u8 cmd_index, u8 r, u8 g, u8 b,
148 enum lp3952_tt tt, enum lp3952_cet cet)
149{
150 int ret;
151 struct ptrn_gen_cmd line = {
152 {
153 {
154 .r = r,
155 .g = g,
156 .b = b,
157 .cet = cet,
158 .tt = tt
159 }
160 }
161 };
162
163 if (cmd_index >= LP3952_CMD_REG_COUNT)
164 return -EINVAL;
165
166 ret = lp3952_register_write(client: priv->client,
167 LP3952_REG_CMD_0 + cmd_index * 2,
168 val: line.bytes.msb);
169 if (ret)
170 return ret;
171
172 return lp3952_register_write(client: priv->client,
173 LP3952_REG_CMD_0 + cmd_index * 2 + 1,
174 val: line.bytes.lsb);
175}
176
177static int lp3952_configure(struct lp3952_led_array *priv)
178{
179 int ret;
180
181 /* Disable any LEDs on from any previous conf. */
182 ret = lp3952_register_write(client: priv->client, LP3952_REG_LED_CTRL, val: 0);
183 if (ret)
184 return ret;
185
186 /* enable rgb patter, loop */
187 ret = lp3952_register_write(client: priv->client, LP3952_REG_PAT_GEN_CTRL,
188 LP3952_PATRN_LOOP | LP3952_PATRN_GEN_EN);
189 if (ret)
190 return ret;
191
192 /* Update Bit 6 (Active mode), Select both Led sets, Bit [1:0] */
193 ret = lp3952_register_write(client: priv->client, LP3952_REG_ENABLES,
194 LP3952_ACTIVE_MODE | LP3952_INT_B00ST_LDR);
195 if (ret)
196 return ret;
197
198 /* Set Cmd1 for RGB intensity,cmd and transition time */
199 return lp3952_set_pattern_gen_cmd(priv, cmd_index: 0, r: I46, g: I71, b: I100, tt: TT0,
200 cet: CET197);
201}
202
203static const struct regmap_config lp3952_regmap = {
204 .reg_bits = 8,
205 .val_bits = 8,
206 .max_register = REG_MAX,
207 .cache_type = REGCACHE_MAPLE,
208};
209
210static void gpio_set_low_action(void *data)
211{
212 struct lp3952_led_array *priv = data;
213
214 gpiod_set_value(desc: priv->enable_gpio, value: 0);
215}
216
217static int lp3952_probe(struct i2c_client *client)
218{
219 int status;
220 struct lp3952_led_array *priv;
221
222 priv = devm_kzalloc(dev: &client->dev, size: sizeof(*priv), GFP_KERNEL);
223 if (!priv)
224 return -ENOMEM;
225
226 priv->client = client;
227
228 priv->enable_gpio = devm_gpiod_get(dev: &client->dev, con_id: "nrst",
229 flags: GPIOD_OUT_HIGH);
230 if (IS_ERR(ptr: priv->enable_gpio)) {
231 status = PTR_ERR(ptr: priv->enable_gpio);
232 dev_err(&client->dev, "Failed to enable gpio: %d\n", status);
233 return status;
234 }
235
236 status = devm_add_action(&client->dev, gpio_set_low_action, priv);
237 if (status)
238 return status;
239
240 priv->regmap = devm_regmap_init_i2c(client, &lp3952_regmap);
241 if (IS_ERR(ptr: priv->regmap)) {
242 int err = PTR_ERR(ptr: priv->regmap);
243
244 dev_err(&client->dev, "Failed to allocate register map: %d\n",
245 err);
246 return err;
247 }
248
249 i2c_set_clientdata(client, data: priv);
250
251 status = lp3952_configure(priv);
252 if (status) {
253 dev_err(&client->dev, "Probe failed. Device not found (%d)\n",
254 status);
255 return status;
256 }
257
258 status = lp3952_register_led_classdev(priv);
259 if (status) {
260 dev_err(&client->dev, "Unable to register led_classdev: %d\n",
261 status);
262 return status;
263 }
264
265 return 0;
266}
267
268static const struct i2c_device_id lp3952_id[] = {
269 { LP3952_NAME },
270 {}
271};
272MODULE_DEVICE_TABLE(i2c, lp3952_id);
273
274static struct i2c_driver lp3952_i2c_driver = {
275 .driver = {
276 .name = LP3952_NAME,
277 },
278 .probe = lp3952_probe,
279 .id_table = lp3952_id,
280};
281
282module_i2c_driver(lp3952_i2c_driver);
283
284MODULE_AUTHOR("Tony Makkiel <tony.makkiel@daqri.com>");
285MODULE_DESCRIPTION("lp3952 I2C LED controller driver");
286MODULE_LICENSE("GPL v2");
287

source code of linux/drivers/leds/leds-lp3952.c