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->enable_gpio, 1);
118 } else {
119 gpiod_set_value_cansleep(priv->enable_gpio, 0);
120 ret = regulator_disable(priv->vin_regulator);
121 if (ret) {
122 dev_err(led_cdev->dev,
123 "failed to disable regulator: %d\n", ret);
124 return ret;
125 }
126 }
127
128 priv->enabled = enable;
129
130 return 0;
131 }
132
sgm3140_powerdown_timer(struct timer_list * t)133 static void sgm3140_powerdown_timer(struct timer_list *t)
134 {
135 struct sgm3140 *priv = from_timer(priv, t, powerdown_timer);
136
137 gpiod_set_value(priv->enable_gpio, 0);
138 gpiod_set_value(priv->flash_gpio, 0);
139 regulator_disable(priv->vin_regulator);
140
141 priv->enabled = false;
142 }
143
sgm3140_init_flash_timeout(struct sgm3140 * priv)144 static void sgm3140_init_flash_timeout(struct sgm3140 *priv)
145 {
146 struct led_classdev_flash *fled_cdev = &priv->fled_cdev;
147 struct led_flash_setting *s;
148
149 /* Init flash timeout setting */
150 s = &fled_cdev->timeout;
151 s->min = 1;
152 s->max = priv->max_timeout;
153 s->step = 1;
154 s->val = FLASH_TIMEOUT_DEFAULT;
155 }
156
157 #if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
sgm3140_init_v4l2_flash_config(struct sgm3140 * priv,struct v4l2_flash_config * v4l2_sd_cfg)158 static void sgm3140_init_v4l2_flash_config(struct sgm3140 *priv,
159 struct v4l2_flash_config *v4l2_sd_cfg)
160 {
161 struct led_classdev *led_cdev = &priv->fled_cdev.led_cdev;
162 struct led_flash_setting *s;
163
164 strscpy(v4l2_sd_cfg->dev_name, led_cdev->dev->kobj.name,
165 sizeof(v4l2_sd_cfg->dev_name));
166
167 /* Init flash intensity setting */
168 s = &v4l2_sd_cfg->intensity;
169 s->min = 0;
170 s->max = 1;
171 s->step = 1;
172 s->val = 1;
173 }
174
175 #else
sgm3140_init_v4l2_flash_config(struct sgm3140 * priv,struct v4l2_flash_config * v4l2_sd_cfg)176 static void sgm3140_init_v4l2_flash_config(struct sgm3140 *priv,
177 struct v4l2_flash_config *v4l2_sd_cfg)
178 {
179 }
180 #endif
181
sgm3140_probe(struct platform_device * pdev)182 static int sgm3140_probe(struct platform_device *pdev)
183 {
184 struct sgm3140 *priv;
185 struct led_classdev *led_cdev;
186 struct led_classdev_flash *fled_cdev;
187 struct led_init_data init_data = {};
188 struct fwnode_handle *child_node;
189 struct v4l2_flash_config v4l2_sd_cfg = {};
190 int ret;
191
192 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
193 if (!priv)
194 return -ENOMEM;
195
196 priv->flash_gpio = devm_gpiod_get(&pdev->dev, "flash", GPIOD_OUT_LOW);
197 ret = PTR_ERR_OR_ZERO(priv->flash_gpio);
198 if (ret)
199 return dev_err_probe(&pdev->dev, ret,
200 "Failed to request flash gpio\n");
201
202 priv->enable_gpio = devm_gpiod_get(&pdev->dev, "enable", GPIOD_OUT_LOW);
203 ret = PTR_ERR_OR_ZERO(priv->enable_gpio);
204 if (ret)
205 return dev_err_probe(&pdev->dev, ret,
206 "Failed to request enable gpio\n");
207
208 priv->vin_regulator = devm_regulator_get(&pdev->dev, "vin");
209 ret = PTR_ERR_OR_ZERO(priv->vin_regulator);
210 if (ret)
211 return dev_err_probe(&pdev->dev, ret,
212 "Failed to request regulator\n");
213
214 child_node = fwnode_get_next_available_child_node(pdev->dev.fwnode,
215 NULL);
216 if (!child_node) {
217 dev_err(&pdev->dev,
218 "No fwnode child node found for connected LED.\n");
219 return -EINVAL;
220 }
221
222 ret = fwnode_property_read_u32(child_node, "flash-max-timeout-us",
223 &priv->max_timeout);
224 if (ret) {
225 priv->max_timeout = FLASH_MAX_TIMEOUT_DEFAULT;
226 dev_warn(&pdev->dev,
227 "flash-max-timeout-us property missing\n");
228 }
229
230 /*
231 * Set default timeout to FLASH_DEFAULT_TIMEOUT except if max_timeout
232 * from DT is lower.
233 */
234 priv->timeout = min(priv->max_timeout, FLASH_TIMEOUT_DEFAULT);
235
236 timer_setup(&priv->powerdown_timer, sgm3140_powerdown_timer, 0);
237
238 fled_cdev = &priv->fled_cdev;
239 led_cdev = &fled_cdev->led_cdev;
240
241 fled_cdev->ops = &sgm3140_flash_ops;
242
243 led_cdev->brightness_set_blocking = sgm3140_brightness_set;
244 led_cdev->max_brightness = LED_ON;
245 led_cdev->flags |= LED_DEV_CAP_FLASH;
246
247 sgm3140_init_flash_timeout(priv);
248
249 init_data.fwnode = child_node;
250
251 platform_set_drvdata(pdev, priv);
252
253 /* Register in the LED subsystem */
254 ret = devm_led_classdev_flash_register_ext(&pdev->dev,
255 fled_cdev, &init_data);
256 if (ret) {
257 dev_err(&pdev->dev, "Failed to register flash device: %d\n",
258 ret);
259 goto err;
260 }
261
262 sgm3140_init_v4l2_flash_config(priv, &v4l2_sd_cfg);
263
264 /* Create V4L2 Flash subdev */
265 priv->v4l2_flash = v4l2_flash_init(&pdev->dev,
266 child_node,
267 fled_cdev, NULL,
268 &v4l2_sd_cfg);
269 if (IS_ERR(priv->v4l2_flash)) {
270 ret = PTR_ERR(priv->v4l2_flash);
271 goto err;
272 }
273
274 return ret;
275
276 err:
277 fwnode_handle_put(child_node);
278 return ret;
279 }
280
sgm3140_remove(struct platform_device * pdev)281 static int sgm3140_remove(struct platform_device *pdev)
282 {
283 struct sgm3140 *priv = platform_get_drvdata(pdev);
284
285 del_timer_sync(&priv->powerdown_timer);
286
287 v4l2_flash_release(priv->v4l2_flash);
288
289 return 0;
290 }
291
292 static const struct of_device_id sgm3140_dt_match[] = {
293 { .compatible = "sgmicro,sgm3140" },
294 { /* sentinel */ }
295 };
296 MODULE_DEVICE_TABLE(of, sgm3140_dt_match);
297
298 static struct platform_driver sgm3140_driver = {
299 .probe = sgm3140_probe,
300 .remove = sgm3140_remove,
301 .driver = {
302 .name = "sgm3140",
303 .of_match_table = sgm3140_dt_match,
304 },
305 };
306
307 module_platform_driver(sgm3140_driver);
308
309 MODULE_AUTHOR("Luca Weiss <luca@z3ntu.xyz>");
310 MODULE_DESCRIPTION("SG Micro SGM3140 charge pump LED driver");
311 MODULE_LICENSE("GPL v2");
312