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
15 struct 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
flcdev_to_sgm3140(struct led_classdev_flash * flcdev)33 static struct sgm3140 *flcdev_to_sgm3140(struct led_classdev_flash *flcdev)
34 {
35 return container_of(flcdev, struct sgm3140, fled_cdev);
36 }
37
sgm3140_strobe_set(struct led_classdev_flash * fled_cdev,bool state)38 static int sgm3140_strobe_set(struct led_classdev_flash *fled_cdev, bool state)
39 {
40 struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);
41 int ret;
42
43 if (priv->enabled == state)
44 return 0;
45
46 if (state) {
47 ret = regulator_enable(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(priv->flash_gpio, 1);
54 gpiod_set_value_cansleep(priv->enable_gpio, 1);
55 mod_timer(&priv->powerdown_timer,
56 jiffies + usecs_to_jiffies(priv->timeout));
57 } else {
58 del_timer_sync(&priv->powerdown_timer);
59 gpiod_set_value_cansleep(priv->enable_gpio, 0);
60 gpiod_set_value_cansleep(priv->flash_gpio, 0);
61 ret = regulator_disable(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
sgm3140_strobe_get(struct led_classdev_flash * fled_cdev,bool * state)74 static int sgm3140_strobe_get(struct led_classdev_flash *fled_cdev, bool *state)
75 {
76 struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);
77
78 *state = timer_pending(&priv->powerdown_timer);
79
80 return 0;
81 }
82
sgm3140_timeout_set(struct led_classdev_flash * fled_cdev,u32 timeout)83 static int sgm3140_timeout_set(struct led_classdev_flash *fled_cdev,
84 u32 timeout)
85 {
86 struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);
87
88 priv->timeout = timeout;
89
90 return 0;
91 }
92
93 static 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
sgm3140_brightness_set(struct led_classdev * led_cdev,enum led_brightness brightness)99 static 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(led_cdev);
103 struct sgm3140 *priv = flcdev_to_sgm3140(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(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(priv->flash_gpio, 0);
118 gpiod_set_value_cansleep(priv->enable_gpio, 1);
119 } else {
120 del_timer_sync(&priv->powerdown_timer);
121 gpiod_set_value_cansleep(priv->flash_gpio, 0);
122 gpiod_set_value_cansleep(priv->enable_gpio, 0);
123 ret = regulator_disable(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
sgm3140_powerdown_timer(struct timer_list * t)136 static void sgm3140_powerdown_timer(struct timer_list *t)
137 {
138 struct sgm3140 *priv = from_timer(priv, t, powerdown_timer);
139
140 gpiod_set_value(priv->enable_gpio, 0);
141 gpiod_set_value(priv->flash_gpio, 0);
142 regulator_disable(priv->vin_regulator);
143
144 priv->enabled = false;
145 }
146
sgm3140_init_flash_timeout(struct sgm3140 * priv)147 static 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)
sgm3140_init_v4l2_flash_config(struct sgm3140 * priv,struct v4l2_flash_config * v4l2_sd_cfg)161 static 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
sgm3140_init_v4l2_flash_config(struct sgm3140 * priv,struct v4l2_flash_config * v4l2_sd_cfg)179 static void sgm3140_init_v4l2_flash_config(struct sgm3140 *priv,
180 struct v4l2_flash_config *v4l2_sd_cfg)
181 {
182 }
183 #endif
184
sgm3140_probe(struct platform_device * pdev)185 static 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(&pdev->dev, sizeof(*priv), GFP_KERNEL);
196 if (!priv)
197 return -ENOMEM;
198
199 priv->flash_gpio = devm_gpiod_get(&pdev->dev, "flash", GPIOD_OUT_LOW);
200 ret = PTR_ERR_OR_ZERO(priv->flash_gpio);
201 if (ret)
202 return dev_err_probe(&pdev->dev, ret,
203 "Failed to request flash gpio\n");
204
205 priv->enable_gpio = devm_gpiod_get(&pdev->dev, "enable", GPIOD_OUT_LOW);
206 ret = PTR_ERR_OR_ZERO(priv->enable_gpio);
207 if (ret)
208 return dev_err_probe(&pdev->dev, ret,
209 "Failed to request enable gpio\n");
210
211 priv->vin_regulator = devm_regulator_get(&pdev->dev, "vin");
212 ret = PTR_ERR_OR_ZERO(priv->vin_regulator);
213 if (ret)
214 return dev_err_probe(&pdev->dev, ret,
215 "Failed to request regulator\n");
216
217 child_node = fwnode_get_next_available_child_node(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(child_node, "flash-max-timeout-us",
226 &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, priv);
255
256 /* Register in the LED subsystem */
257 ret = devm_led_classdev_flash_register_ext(&pdev->dev,
258 fled_cdev, &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);
266
267 /* Create V4L2 Flash subdev */
268 priv->v4l2_flash = v4l2_flash_init(&pdev->dev,
269 child_node,
270 fled_cdev, NULL,
271 &v4l2_sd_cfg);
272 if (IS_ERR(priv->v4l2_flash)) {
273 ret = PTR_ERR(priv->v4l2_flash);
274 goto err;
275 }
276
277 return ret;
278
279 err:
280 fwnode_handle_put(child_node);
281 return ret;
282 }
283
sgm3140_remove(struct platform_device * pdev)284 static int sgm3140_remove(struct platform_device *pdev)
285 {
286 struct sgm3140 *priv = platform_get_drvdata(pdev);
287
288 del_timer_sync(&priv->powerdown_timer);
289
290 v4l2_flash_release(priv->v4l2_flash);
291
292 return 0;
293 }
294
295 static const struct of_device_id sgm3140_dt_match[] = {
296 { .compatible = "ocs,ocp8110" },
297 { .compatible = "richtek,rt5033-led" },
298 { .compatible = "sgmicro,sgm3140" },
299 { /* sentinel */ }
300 };
301 MODULE_DEVICE_TABLE(of, sgm3140_dt_match);
302
303 static struct platform_driver sgm3140_driver = {
304 .probe = sgm3140_probe,
305 .remove = sgm3140_remove,
306 .driver = {
307 .name = "sgm3140",
308 .of_match_table = sgm3140_dt_match,
309 },
310 };
311
312 module_platform_driver(sgm3140_driver);
313
314 MODULE_AUTHOR("Luca Weiss <luca@z3ntu.xyz>");
315 MODULE_DESCRIPTION("SG Micro SGM3140 charge pump LED driver");
316 MODULE_LICENSE("GPL v2");
317