1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * lm3533-bl.c -- LM3533 Backlight driver
4 *
5 * Copyright (C) 2011-2012 Texas Instruments
6 *
7 * Author: Johan Hovold <jhovold@gmail.com>
8 */
9
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/platform_device.h>
13 #include <linux/backlight.h>
14 #include <linux/slab.h>
15
16 #include <linux/mfd/lm3533.h>
17
18
19 #define LM3533_HVCTRLBANK_COUNT 2
20 #define LM3533_BL_MAX_BRIGHTNESS 255
21
22 #define LM3533_REG_CTRLBANK_AB_BCONF 0x1a
23
24
25 struct lm3533_bl {
26 struct lm3533 *lm3533;
27 struct lm3533_ctrlbank cb;
28 struct backlight_device *bd;
29 int id;
30 };
31
32
lm3533_bl_get_ctrlbank_id(struct lm3533_bl * bl)33 static inline int lm3533_bl_get_ctrlbank_id(struct lm3533_bl *bl)
34 {
35 return bl->id;
36 }
37
lm3533_bl_update_status(struct backlight_device * bd)38 static int lm3533_bl_update_status(struct backlight_device *bd)
39 {
40 struct lm3533_bl *bl = bl_get_data(bd);
41
42 return lm3533_ctrlbank_set_brightness(&bl->cb, backlight_get_brightness(bd));
43 }
44
lm3533_bl_get_brightness(struct backlight_device * bd)45 static int lm3533_bl_get_brightness(struct backlight_device *bd)
46 {
47 struct lm3533_bl *bl = bl_get_data(bd);
48 u8 val;
49 int ret;
50
51 ret = lm3533_ctrlbank_get_brightness(&bl->cb, &val);
52 if (ret)
53 return ret;
54
55 return val;
56 }
57
58 static const struct backlight_ops lm3533_bl_ops = {
59 .get_brightness = lm3533_bl_get_brightness,
60 .update_status = lm3533_bl_update_status,
61 };
62
show_id(struct device * dev,struct device_attribute * attr,char * buf)63 static ssize_t show_id(struct device *dev,
64 struct device_attribute *attr, char *buf)
65 {
66 struct lm3533_bl *bl = dev_get_drvdata(dev);
67
68 return scnprintf(buf, PAGE_SIZE, "%d\n", bl->id);
69 }
70
show_als_channel(struct device * dev,struct device_attribute * attr,char * buf)71 static ssize_t show_als_channel(struct device *dev,
72 struct device_attribute *attr, char *buf)
73 {
74 struct lm3533_bl *bl = dev_get_drvdata(dev);
75 unsigned channel = lm3533_bl_get_ctrlbank_id(bl);
76
77 return scnprintf(buf, PAGE_SIZE, "%u\n", channel);
78 }
79
show_als_en(struct device * dev,struct device_attribute * attr,char * buf)80 static ssize_t show_als_en(struct device *dev,
81 struct device_attribute *attr, char *buf)
82 {
83 struct lm3533_bl *bl = dev_get_drvdata(dev);
84 int ctrlbank = lm3533_bl_get_ctrlbank_id(bl);
85 u8 val;
86 u8 mask;
87 bool enable;
88 int ret;
89
90 ret = lm3533_read(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, &val);
91 if (ret)
92 return ret;
93
94 mask = 1 << (2 * ctrlbank);
95 enable = val & mask;
96
97 return scnprintf(buf, PAGE_SIZE, "%d\n", enable);
98 }
99
store_als_en(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)100 static ssize_t store_als_en(struct device *dev,
101 struct device_attribute *attr,
102 const char *buf, size_t len)
103 {
104 struct lm3533_bl *bl = dev_get_drvdata(dev);
105 int ctrlbank = lm3533_bl_get_ctrlbank_id(bl);
106 int enable;
107 u8 val;
108 u8 mask;
109 int ret;
110
111 if (kstrtoint(buf, 0, &enable))
112 return -EINVAL;
113
114 mask = 1 << (2 * ctrlbank);
115
116 if (enable)
117 val = mask;
118 else
119 val = 0;
120
121 ret = lm3533_update(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, val,
122 mask);
123 if (ret)
124 return ret;
125
126 return len;
127 }
128
show_linear(struct device * dev,struct device_attribute * attr,char * buf)129 static ssize_t show_linear(struct device *dev,
130 struct device_attribute *attr, char *buf)
131 {
132 struct lm3533_bl *bl = dev_get_drvdata(dev);
133 u8 val;
134 u8 mask;
135 int linear;
136 int ret;
137
138 ret = lm3533_read(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, &val);
139 if (ret)
140 return ret;
141
142 mask = 1 << (2 * lm3533_bl_get_ctrlbank_id(bl) + 1);
143
144 if (val & mask)
145 linear = 1;
146 else
147 linear = 0;
148
149 return scnprintf(buf, PAGE_SIZE, "%x\n", linear);
150 }
151
store_linear(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)152 static ssize_t store_linear(struct device *dev,
153 struct device_attribute *attr,
154 const char *buf, size_t len)
155 {
156 struct lm3533_bl *bl = dev_get_drvdata(dev);
157 unsigned long linear;
158 u8 mask;
159 u8 val;
160 int ret;
161
162 if (kstrtoul(buf, 0, &linear))
163 return -EINVAL;
164
165 mask = 1 << (2 * lm3533_bl_get_ctrlbank_id(bl) + 1);
166
167 if (linear)
168 val = mask;
169 else
170 val = 0;
171
172 ret = lm3533_update(bl->lm3533, LM3533_REG_CTRLBANK_AB_BCONF, val,
173 mask);
174 if (ret)
175 return ret;
176
177 return len;
178 }
179
show_pwm(struct device * dev,struct device_attribute * attr,char * buf)180 static ssize_t show_pwm(struct device *dev,
181 struct device_attribute *attr,
182 char *buf)
183 {
184 struct lm3533_bl *bl = dev_get_drvdata(dev);
185 u8 val;
186 int ret;
187
188 ret = lm3533_ctrlbank_get_pwm(&bl->cb, &val);
189 if (ret)
190 return ret;
191
192 return scnprintf(buf, PAGE_SIZE, "%u\n", val);
193 }
194
store_pwm(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)195 static ssize_t store_pwm(struct device *dev,
196 struct device_attribute *attr,
197 const char *buf, size_t len)
198 {
199 struct lm3533_bl *bl = dev_get_drvdata(dev);
200 u8 val;
201 int ret;
202
203 if (kstrtou8(buf, 0, &val))
204 return -EINVAL;
205
206 ret = lm3533_ctrlbank_set_pwm(&bl->cb, val);
207 if (ret)
208 return ret;
209
210 return len;
211 }
212
213 static LM3533_ATTR_RO(als_channel);
214 static LM3533_ATTR_RW(als_en);
215 static LM3533_ATTR_RO(id);
216 static LM3533_ATTR_RW(linear);
217 static LM3533_ATTR_RW(pwm);
218
219 static struct attribute *lm3533_bl_attributes[] = {
220 &dev_attr_als_channel.attr,
221 &dev_attr_als_en.attr,
222 &dev_attr_id.attr,
223 &dev_attr_linear.attr,
224 &dev_attr_pwm.attr,
225 NULL,
226 };
227
lm3533_bl_attr_is_visible(struct kobject * kobj,struct attribute * attr,int n)228 static umode_t lm3533_bl_attr_is_visible(struct kobject *kobj,
229 struct attribute *attr, int n)
230 {
231 struct device *dev = kobj_to_dev(kobj);
232 struct lm3533_bl *bl = dev_get_drvdata(dev);
233 umode_t mode = attr->mode;
234
235 if (attr == &dev_attr_als_channel.attr ||
236 attr == &dev_attr_als_en.attr) {
237 if (!bl->lm3533->have_als)
238 mode = 0;
239 }
240
241 return mode;
242 };
243
244 static struct attribute_group lm3533_bl_attribute_group = {
245 .is_visible = lm3533_bl_attr_is_visible,
246 .attrs = lm3533_bl_attributes
247 };
248
lm3533_bl_setup(struct lm3533_bl * bl,struct lm3533_bl_platform_data * pdata)249 static int lm3533_bl_setup(struct lm3533_bl *bl,
250 struct lm3533_bl_platform_data *pdata)
251 {
252 int ret;
253
254 ret = lm3533_ctrlbank_set_max_current(&bl->cb, pdata->max_current);
255 if (ret)
256 return ret;
257
258 return lm3533_ctrlbank_set_pwm(&bl->cb, pdata->pwm);
259 }
260
lm3533_bl_probe(struct platform_device * pdev)261 static int lm3533_bl_probe(struct platform_device *pdev)
262 {
263 struct lm3533 *lm3533;
264 struct lm3533_bl_platform_data *pdata;
265 struct lm3533_bl *bl;
266 struct backlight_device *bd;
267 struct backlight_properties props;
268 int ret;
269
270 dev_dbg(&pdev->dev, "%s\n", __func__);
271
272 lm3533 = dev_get_drvdata(pdev->dev.parent);
273 if (!lm3533)
274 return -EINVAL;
275
276 pdata = dev_get_platdata(&pdev->dev);
277 if (!pdata) {
278 dev_err(&pdev->dev, "no platform data\n");
279 return -EINVAL;
280 }
281
282 if (pdev->id < 0 || pdev->id >= LM3533_HVCTRLBANK_COUNT) {
283 dev_err(&pdev->dev, "illegal backlight id %d\n", pdev->id);
284 return -EINVAL;
285 }
286
287 bl = devm_kzalloc(&pdev->dev, sizeof(*bl), GFP_KERNEL);
288 if (!bl)
289 return -ENOMEM;
290
291 bl->lm3533 = lm3533;
292 bl->id = pdev->id;
293
294 bl->cb.lm3533 = lm3533;
295 bl->cb.id = lm3533_bl_get_ctrlbank_id(bl);
296 bl->cb.dev = NULL; /* until registered */
297
298 memset(&props, 0, sizeof(props));
299 props.type = BACKLIGHT_RAW;
300 props.max_brightness = LM3533_BL_MAX_BRIGHTNESS;
301 props.brightness = pdata->default_brightness;
302 bd = devm_backlight_device_register(&pdev->dev, pdata->name,
303 pdev->dev.parent, bl, &lm3533_bl_ops,
304 &props);
305 if (IS_ERR(bd)) {
306 dev_err(&pdev->dev, "failed to register backlight device\n");
307 return PTR_ERR(bd);
308 }
309
310 bl->bd = bd;
311 bl->cb.dev = &bl->bd->dev;
312
313 platform_set_drvdata(pdev, bl);
314
315 ret = sysfs_create_group(&bd->dev.kobj, &lm3533_bl_attribute_group);
316 if (ret < 0) {
317 dev_err(&pdev->dev, "failed to create sysfs attributes\n");
318 return ret;
319 }
320
321 backlight_update_status(bd);
322
323 ret = lm3533_bl_setup(bl, pdata);
324 if (ret)
325 goto err_sysfs_remove;
326
327 ret = lm3533_ctrlbank_enable(&bl->cb);
328 if (ret)
329 goto err_sysfs_remove;
330
331 return 0;
332
333 err_sysfs_remove:
334 sysfs_remove_group(&bd->dev.kobj, &lm3533_bl_attribute_group);
335
336 return ret;
337 }
338
lm3533_bl_remove(struct platform_device * pdev)339 static void lm3533_bl_remove(struct platform_device *pdev)
340 {
341 struct lm3533_bl *bl = platform_get_drvdata(pdev);
342 struct backlight_device *bd = bl->bd;
343
344 dev_dbg(&bd->dev, "%s\n", __func__);
345
346 bd->props.power = BACKLIGHT_POWER_OFF;
347 bd->props.brightness = 0;
348
349 lm3533_ctrlbank_disable(&bl->cb);
350 sysfs_remove_group(&bd->dev.kobj, &lm3533_bl_attribute_group);
351 }
352
353 #ifdef CONFIG_PM_SLEEP
lm3533_bl_suspend(struct device * dev)354 static int lm3533_bl_suspend(struct device *dev)
355 {
356 struct lm3533_bl *bl = dev_get_drvdata(dev);
357
358 dev_dbg(dev, "%s\n", __func__);
359
360 return lm3533_ctrlbank_disable(&bl->cb);
361 }
362
lm3533_bl_resume(struct device * dev)363 static int lm3533_bl_resume(struct device *dev)
364 {
365 struct lm3533_bl *bl = dev_get_drvdata(dev);
366
367 dev_dbg(dev, "%s\n", __func__);
368
369 return lm3533_ctrlbank_enable(&bl->cb);
370 }
371 #endif
372
373 static SIMPLE_DEV_PM_OPS(lm3533_bl_pm_ops, lm3533_bl_suspend, lm3533_bl_resume);
374
lm3533_bl_shutdown(struct platform_device * pdev)375 static void lm3533_bl_shutdown(struct platform_device *pdev)
376 {
377 struct lm3533_bl *bl = platform_get_drvdata(pdev);
378
379 dev_dbg(&pdev->dev, "%s\n", __func__);
380
381 lm3533_ctrlbank_disable(&bl->cb);
382 }
383
384 static struct platform_driver lm3533_bl_driver = {
385 .driver = {
386 .name = "lm3533-backlight",
387 .pm = &lm3533_bl_pm_ops,
388 },
389 .probe = lm3533_bl_probe,
390 .remove_new = lm3533_bl_remove,
391 .shutdown = lm3533_bl_shutdown,
392 };
393 module_platform_driver(lm3533_bl_driver);
394
395 MODULE_AUTHOR("Johan Hovold <jhovold@gmail.com>");
396 MODULE_DESCRIPTION("LM3533 Backlight driver");
397 MODULE_LICENSE("GPL");
398 MODULE_ALIAS("platform:lm3533-backlight");
399