1// SPDX-License-Identifier: GPL-2.0
2// Copyright (C) 2020 Luca Weiss <luca@z3ntu.xyz>
3
4#include <linux/gpio/consumer.h>
5#include <linux/led-class-flash.h>
6#include <linux/module.h>
7#include <linux/regulator/consumer.h>
8#include <linux/platform_device.h>
9
10#include <media/v4l2-flash-led-class.h>
11
12#define FLASH_TIMEOUT_DEFAULT 250000U /* 250ms */
13#define FLASH_MAX_TIMEOUT_DEFAULT 300000U /* 300ms */
14
15struct sgm3140 {
16 struct led_classdev_flash fled_cdev;
17 struct v4l2_flash *v4l2_flash;
18
19 struct timer_list powerdown_timer;
20
21 struct gpio_desc *flash_gpio;
22 struct gpio_desc *enable_gpio;
23 struct regulator *vin_regulator;
24
25 bool enabled;
26
27 /* current timeout in us */
28 u32 timeout;
29 /* maximum timeout in us */
30 u32 max_timeout;
31};
32
33static struct sgm3140 *flcdev_to_sgm3140(struct led_classdev_flash *flcdev)
34{
35 return container_of(flcdev, struct sgm3140, fled_cdev);
36}
37
38static int sgm3140_strobe_set(struct led_classdev_flash *fled_cdev, bool state)
39{
40 struct sgm3140 *priv = flcdev_to_sgm3140(flcdev: fled_cdev);
41 int ret;
42
43 if (priv->enabled == state)
44 return 0;
45
46 if (state) {
47 ret = regulator_enable(regulator: priv->vin_regulator);
48 if (ret) {
49 dev_err(fled_cdev->led_cdev.dev,
50 "failed to enable regulator: %d\n", ret);
51 return ret;
52 }
53 gpiod_set_value_cansleep(desc: priv->flash_gpio, value: 1);
54 gpiod_set_value_cansleep(desc: priv->enable_gpio, value: 1);
55 mod_timer(timer: &priv->powerdown_timer,
56 expires: jiffies + usecs_to_jiffies(u: priv->timeout));
57 } else {
58 del_timer_sync(timer: &priv->powerdown_timer);
59 gpiod_set_value_cansleep(desc: priv->enable_gpio, value: 0);
60 gpiod_set_value_cansleep(desc: priv->flash_gpio, value: 0);
61 ret = regulator_disable(regulator: priv->vin_regulator);
62 if (ret) {
63 dev_err(fled_cdev->led_cdev.dev,
64 "failed to disable regulator: %d\n", ret);
65 return ret;
66 }
67 }
68
69 priv->enabled = state;
70
71 return 0;
72}
73
74static int sgm3140_strobe_get(struct led_classdev_flash *fled_cdev, bool *state)
75{
76 struct sgm3140 *priv = flcdev_to_sgm3140(flcdev: fled_cdev);
77
78 *state = timer_pending(timer: &priv->powerdown_timer);
79
80 return 0;
81}
82
83static int sgm3140_timeout_set(struct led_classdev_flash *fled_cdev,
84 u32 timeout)
85{
86 struct sgm3140 *priv = flcdev_to_sgm3140(flcdev: fled_cdev);
87
88 priv->timeout = timeout;
89
90 return 0;
91}
92
93static const struct led_flash_ops sgm3140_flash_ops = {
94 .strobe_set = sgm3140_strobe_set,
95 .strobe_get = sgm3140_strobe_get,
96 .timeout_set = sgm3140_timeout_set,
97};
98
99static int sgm3140_brightness_set(struct led_classdev *led_cdev,
100 enum led_brightness brightness)
101{
102 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(lcdev: led_cdev);
103 struct sgm3140 *priv = flcdev_to_sgm3140(flcdev: fled_cdev);
104 bool enable = brightness == LED_ON;
105 int ret;
106
107 if (priv->enabled == enable)
108 return 0;
109
110 if (enable) {
111 ret = regulator_enable(regulator: priv->vin_regulator);
112 if (ret) {
113 dev_err(led_cdev->dev,
114 "failed to enable regulator: %d\n", ret);
115 return ret;
116 }
117 gpiod_set_value_cansleep(desc: priv->flash_gpio, value: 0);
118 gpiod_set_value_cansleep(desc: priv->enable_gpio, value: 1);
119 } else {
120 del_timer_sync(timer: &priv->powerdown_timer);
121 gpiod_set_value_cansleep(desc: priv->flash_gpio, value: 0);
122 gpiod_set_value_cansleep(desc: priv->enable_gpio, value: 0);
123 ret = regulator_disable(regulator: priv->vin_regulator);
124 if (ret) {
125 dev_err(led_cdev->dev,
126 "failed to disable regulator: %d\n", ret);
127 return ret;
128 }
129 }
130
131 priv->enabled = enable;
132
133 return 0;
134}
135
136static void sgm3140_powerdown_timer(struct timer_list *t)
137{
138 struct sgm3140 *priv = from_timer(priv, t, powerdown_timer);
139
140 gpiod_set_value(desc: priv->enable_gpio, value: 0);
141 gpiod_set_value(desc: priv->flash_gpio, value: 0);
142 regulator_disable(regulator: priv->vin_regulator);
143
144 priv->enabled = false;
145}
146
147static void sgm3140_init_flash_timeout(struct sgm3140 *priv)
148{
149 struct led_classdev_flash *fled_cdev = &priv->fled_cdev;
150 struct led_flash_setting *s;
151
152 /* Init flash timeout setting */
153 s = &fled_cdev->timeout;
154 s->min = 1;
155 s->max = priv->max_timeout;
156 s->step = 1;
157 s->val = FLASH_TIMEOUT_DEFAULT;
158}
159
160#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
161static void sgm3140_init_v4l2_flash_config(struct sgm3140 *priv,
162 struct v4l2_flash_config *v4l2_sd_cfg)
163{
164 struct led_classdev *led_cdev = &priv->fled_cdev.led_cdev;
165 struct led_flash_setting *s;
166
167 strscpy(v4l2_sd_cfg->dev_name, led_cdev->dev->kobj.name,
168 sizeof(v4l2_sd_cfg->dev_name));
169
170 /* Init flash intensity setting */
171 s = &v4l2_sd_cfg->intensity;
172 s->min = 0;
173 s->max = 1;
174 s->step = 1;
175 s->val = 1;
176}
177
178#else
179static void sgm3140_init_v4l2_flash_config(struct sgm3140 *priv,
180 struct v4l2_flash_config *v4l2_sd_cfg)
181{
182}
183#endif
184
185static int sgm3140_probe(struct platform_device *pdev)
186{
187 struct sgm3140 *priv;
188 struct led_classdev *led_cdev;
189 struct led_classdev_flash *fled_cdev;
190 struct led_init_data init_data = {};
191 struct fwnode_handle *child_node;
192 struct v4l2_flash_config v4l2_sd_cfg = {};
193 int ret;
194
195 priv = devm_kzalloc(dev: &pdev->dev, size: sizeof(*priv), GFP_KERNEL);
196 if (!priv)
197 return -ENOMEM;
198
199 priv->flash_gpio = devm_gpiod_get(dev: &pdev->dev, con_id: "flash", flags: GPIOD_OUT_LOW);
200 ret = PTR_ERR_OR_ZERO(ptr: priv->flash_gpio);
201 if (ret)
202 return dev_err_probe(dev: &pdev->dev, err: ret,
203 fmt: "Failed to request flash gpio\n");
204
205 priv->enable_gpio = devm_gpiod_get(dev: &pdev->dev, con_id: "enable", flags: GPIOD_OUT_LOW);
206 ret = PTR_ERR_OR_ZERO(ptr: priv->enable_gpio);
207 if (ret)
208 return dev_err_probe(dev: &pdev->dev, err: ret,
209 fmt: "Failed to request enable gpio\n");
210
211 priv->vin_regulator = devm_regulator_get(dev: &pdev->dev, id: "vin");
212 ret = PTR_ERR_OR_ZERO(ptr: priv->vin_regulator);
213 if (ret)
214 return dev_err_probe(dev: &pdev->dev, err: ret,
215 fmt: "Failed to request regulator\n");
216
217 child_node = fwnode_get_next_available_child_node(fwnode: pdev->dev.fwnode,
218 NULL);
219 if (!child_node) {
220 dev_err(&pdev->dev,
221 "No fwnode child node found for connected LED.\n");
222 return -EINVAL;
223 }
224
225 ret = fwnode_property_read_u32(fwnode: child_node, propname: "flash-max-timeout-us",
226 val: &priv->max_timeout);
227 if (ret) {
228 priv->max_timeout = FLASH_MAX_TIMEOUT_DEFAULT;
229 dev_warn(&pdev->dev,
230 "flash-max-timeout-us property missing\n");
231 }
232
233 /*
234 * Set default timeout to FLASH_DEFAULT_TIMEOUT except if max_timeout
235 * from DT is lower.
236 */
237 priv->timeout = min(priv->max_timeout, FLASH_TIMEOUT_DEFAULT);
238
239 timer_setup(&priv->powerdown_timer, sgm3140_powerdown_timer, 0);
240
241 fled_cdev = &priv->fled_cdev;
242 led_cdev = &fled_cdev->led_cdev;
243
244 fled_cdev->ops = &sgm3140_flash_ops;
245
246 led_cdev->brightness_set_blocking = sgm3140_brightness_set;
247 led_cdev->max_brightness = LED_ON;
248 led_cdev->flags |= LED_DEV_CAP_FLASH;
249
250 sgm3140_init_flash_timeout(priv);
251
252 init_data.fwnode = child_node;
253
254 platform_set_drvdata(pdev, data: priv);
255
256 /* Register in the LED subsystem */
257 ret = devm_led_classdev_flash_register_ext(parent: &pdev->dev,
258 fled_cdev, init_data: &init_data);
259 if (ret) {
260 dev_err(&pdev->dev, "Failed to register flash device: %d\n",
261 ret);
262 goto err;
263 }
264
265 sgm3140_init_v4l2_flash_config(priv, v4l2_sd_cfg: &v4l2_sd_cfg);
266
267 /* Create V4L2 Flash subdev */
268 priv->v4l2_flash = v4l2_flash_init(dev: &pdev->dev,
269 fwn: child_node,
270 fled_cdev, NULL,
271 config: &v4l2_sd_cfg);
272 if (IS_ERR(ptr: priv->v4l2_flash)) {
273 ret = PTR_ERR(ptr: priv->v4l2_flash);
274 goto err;
275 }
276
277 return ret;
278
279err:
280 fwnode_handle_put(fwnode: child_node);
281 return ret;
282}
283
284static void sgm3140_remove(struct platform_device *pdev)
285{
286 struct sgm3140 *priv = platform_get_drvdata(pdev);
287
288 del_timer_sync(timer: &priv->powerdown_timer);
289
290 v4l2_flash_release(v4l2_flash: priv->v4l2_flash);
291}
292
293static const struct of_device_id sgm3140_dt_match[] = {
294 { .compatible = "ocs,ocp8110" },
295 { .compatible = "richtek,rt5033-led" },
296 { .compatible = "sgmicro,sgm3140" },
297 { /* sentinel */ }
298};
299MODULE_DEVICE_TABLE(of, sgm3140_dt_match);
300
301static struct platform_driver sgm3140_driver = {
302 .probe = sgm3140_probe,
303 .remove_new = sgm3140_remove,
304 .driver = {
305 .name = "sgm3140",
306 .of_match_table = sgm3140_dt_match,
307 },
308};
309
310module_platform_driver(sgm3140_driver);
311
312MODULE_AUTHOR("Luca Weiss <luca@z3ntu.xyz>");
313MODULE_DESCRIPTION("SG Micro SGM3140 charge pump LED driver");
314MODULE_LICENSE("GPL v2");
315

source code of linux/drivers/leds/flash/leds-sgm3140.c