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12#include <linux/backlight.h>
13#include <linux/delay.h>
14#include <linux/device.h>
15#include <linux/err.h>
16#include <linux/fb.h>
17#include <linux/kernel.h>
18#include <linux/mfd/as3711.h>
19#include <linux/module.h>
20#include <linux/platform_device.h>
21#include <linux/regmap.h>
22#include <linux/slab.h>
23
24enum as3711_bl_type {
25 AS3711_BL_SU1,
26 AS3711_BL_SU2,
27};
28
29struct as3711_bl_data {
30 bool powered;
31 enum as3711_bl_type type;
32 int brightness;
33 struct backlight_device *bl;
34};
35
36struct as3711_bl_supply {
37 struct as3711_bl_data su1;
38 struct as3711_bl_data su2;
39 const struct as3711_bl_pdata *pdata;
40 struct as3711 *as3711;
41};
42
43static struct as3711_bl_supply *to_supply(struct as3711_bl_data *su)
44{
45 switch (su->type) {
46 case AS3711_BL_SU1:
47 return container_of(su, struct as3711_bl_supply, su1);
48 case AS3711_BL_SU2:
49 return container_of(su, struct as3711_bl_supply, su2);
50 }
51 return NULL;
52}
53
54static int as3711_set_brightness_auto_i(struct as3711_bl_data *data,
55 unsigned int brightness)
56{
57 struct as3711_bl_supply *supply = to_supply(data);
58 struct as3711 *as3711 = supply->as3711;
59 const struct as3711_bl_pdata *pdata = supply->pdata;
60 int ret = 0;
61
62
63 if (pdata->su2_auto_curr1)
64 ret = regmap_write(as3711->regmap, AS3711_CURR1_VALUE,
65 brightness);
66 if (!ret && pdata->su2_auto_curr2)
67 ret = regmap_write(as3711->regmap, AS3711_CURR2_VALUE,
68 brightness);
69 if (!ret && pdata->su2_auto_curr3)
70 ret = regmap_write(as3711->regmap, AS3711_CURR3_VALUE,
71 brightness);
72
73 return ret;
74}
75
76static int as3711_set_brightness_v(struct as3711 *as3711,
77 unsigned int brightness,
78 unsigned int reg)
79{
80 if (brightness > 31)
81 return -EINVAL;
82
83 return regmap_update_bits(as3711->regmap, reg, 0xf0,
84 brightness << 4);
85}
86
87static int as3711_bl_su2_reset(struct as3711_bl_supply *supply)
88{
89 struct as3711 *as3711 = supply->as3711;
90 int ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_5,
91 3, supply->pdata->su2_fbprot);
92 if (!ret)
93 ret = regmap_update_bits(as3711->regmap,
94 AS3711_STEPUP_CONTROL_2, 1, 0);
95 if (!ret)
96 ret = regmap_update_bits(as3711->regmap,
97 AS3711_STEPUP_CONTROL_2, 1, 1);
98 return ret;
99}
100
101
102
103
104
105static int as3711_bl_update_status(struct backlight_device *bl)
106{
107 struct as3711_bl_data *data = bl_get_data(bl);
108 struct as3711_bl_supply *supply = to_supply(data);
109 struct as3711 *as3711 = supply->as3711;
110 int brightness = bl->props.brightness;
111 int ret = 0;
112
113 dev_dbg(&bl->dev, "%s(): brightness %u, pwr %x, blank %x, state %x\n",
114 __func__, bl->props.brightness, bl->props.power,
115 bl->props.fb_blank, bl->props.state);
116
117 if (bl->props.power != FB_BLANK_UNBLANK ||
118 bl->props.fb_blank != FB_BLANK_UNBLANK ||
119 bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
120 brightness = 0;
121
122 if (data->type == AS3711_BL_SU1) {
123 ret = as3711_set_brightness_v(as3711, brightness,
124 AS3711_STEPUP_CONTROL_1);
125 } else {
126 const struct as3711_bl_pdata *pdata = supply->pdata;
127
128 switch (pdata->su2_feedback) {
129 case AS3711_SU2_VOLTAGE:
130 ret = as3711_set_brightness_v(as3711, brightness,
131 AS3711_STEPUP_CONTROL_2);
132 break;
133 case AS3711_SU2_CURR_AUTO:
134 ret = as3711_set_brightness_auto_i(data, brightness / 4);
135 if (ret < 0)
136 return ret;
137 if (brightness) {
138 ret = as3711_bl_su2_reset(supply);
139 if (ret < 0)
140 return ret;
141 udelay(500);
142 ret = as3711_set_brightness_auto_i(data, brightness);
143 } else {
144 ret = regmap_update_bits(as3711->regmap,
145 AS3711_STEPUP_CONTROL_2, 1, 0);
146 }
147 break;
148
149 case AS3711_SU2_CURR1:
150 ret = regmap_write(as3711->regmap, AS3711_CURR1_VALUE,
151 brightness);
152 break;
153 case AS3711_SU2_CURR2:
154 ret = regmap_write(as3711->regmap, AS3711_CURR2_VALUE,
155 brightness);
156 break;
157 case AS3711_SU2_CURR3:
158 ret = regmap_write(as3711->regmap, AS3711_CURR3_VALUE,
159 brightness);
160 break;
161 default:
162 ret = -EINVAL;
163 }
164 }
165 if (!ret)
166 data->brightness = brightness;
167
168 return ret;
169}
170
171static int as3711_bl_get_brightness(struct backlight_device *bl)
172{
173 struct as3711_bl_data *data = bl_get_data(bl);
174
175 return data->brightness;
176}
177
178static const struct backlight_ops as3711_bl_ops = {
179 .update_status = as3711_bl_update_status,
180 .get_brightness = as3711_bl_get_brightness,
181};
182
183static int as3711_bl_init_su2(struct as3711_bl_supply *supply)
184{
185 struct as3711 *as3711 = supply->as3711;
186 const struct as3711_bl_pdata *pdata = supply->pdata;
187 u8 ctl = 0;
188 int ret;
189
190 dev_dbg(as3711->dev, "%s(): use %u\n", __func__, pdata->su2_feedback);
191
192
193 ret = regmap_write(as3711->regmap, AS3711_STEPUP_CONTROL_2, 0);
194 if (ret < 0)
195 return ret;
196
197 switch (pdata->su2_feedback) {
198 case AS3711_SU2_VOLTAGE:
199 ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 0);
200 break;
201 case AS3711_SU2_CURR1:
202 ctl = 1;
203 ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 1);
204 break;
205 case AS3711_SU2_CURR2:
206 ctl = 4;
207 ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 2);
208 break;
209 case AS3711_SU2_CURR3:
210 ctl = 0x10;
211 ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 3);
212 break;
213 case AS3711_SU2_CURR_AUTO:
214 if (pdata->su2_auto_curr1)
215 ctl = 2;
216 if (pdata->su2_auto_curr2)
217 ctl |= 8;
218 if (pdata->su2_auto_curr3)
219 ctl |= 0x20;
220 ret = 0;
221 break;
222 default:
223 return -EINVAL;
224 }
225
226 if (!ret)
227 ret = regmap_write(as3711->regmap, AS3711_CURR_CONTROL, ctl);
228
229 return ret;
230}
231
232static int as3711_bl_register(struct platform_device *pdev,
233 unsigned int max_brightness, struct as3711_bl_data *su)
234{
235 struct backlight_properties props = {.type = BACKLIGHT_RAW,};
236 struct backlight_device *bl;
237
238
239 props.max_brightness = max_brightness;
240
241 bl = devm_backlight_device_register(&pdev->dev,
242 su->type == AS3711_BL_SU1 ?
243 "as3711-su1" : "as3711-su2",
244 &pdev->dev, su,
245 &as3711_bl_ops, &props);
246 if (IS_ERR(bl)) {
247 dev_err(&pdev->dev, "failed to register backlight\n");
248 return PTR_ERR(bl);
249 }
250
251 bl->props.brightness = props.max_brightness;
252
253 backlight_update_status(bl);
254
255 su->bl = bl;
256
257 return 0;
258}
259
260static int as3711_backlight_parse_dt(struct device *dev)
261{
262 struct as3711_bl_pdata *pdata = dev_get_platdata(dev);
263 struct device_node *bl, *fb;
264 int ret;
265
266 bl = of_get_child_by_name(dev->parent->of_node, "backlight");
267 if (!bl) {
268 dev_dbg(dev, "backlight node not found\n");
269 return -ENODEV;
270 }
271
272 fb = of_parse_phandle(bl, "su1-dev", 0);
273 if (fb) {
274 of_node_put(fb);
275
276 pdata->su1_fb = true;
277
278 ret = of_property_read_u32(bl, "su1-max-uA", &pdata->su1_max_uA);
279 if (pdata->su1_max_uA <= 0)
280 ret = -EINVAL;
281 if (ret < 0)
282 goto err_put_bl;
283 }
284
285 fb = of_parse_phandle(bl, "su2-dev", 0);
286 if (fb) {
287 int count = 0;
288
289 of_node_put(fb);
290
291 pdata->su2_fb = true;
292
293 ret = of_property_read_u32(bl, "su2-max-uA", &pdata->su2_max_uA);
294 if (pdata->su2_max_uA <= 0)
295 ret = -EINVAL;
296 if (ret < 0)
297 goto err_put_bl;
298
299 if (of_find_property(bl, "su2-feedback-voltage", NULL)) {
300 pdata->su2_feedback = AS3711_SU2_VOLTAGE;
301 count++;
302 }
303 if (of_find_property(bl, "su2-feedback-curr1", NULL)) {
304 pdata->su2_feedback = AS3711_SU2_CURR1;
305 count++;
306 }
307 if (of_find_property(bl, "su2-feedback-curr2", NULL)) {
308 pdata->su2_feedback = AS3711_SU2_CURR2;
309 count++;
310 }
311 if (of_find_property(bl, "su2-feedback-curr3", NULL)) {
312 pdata->su2_feedback = AS3711_SU2_CURR3;
313 count++;
314 }
315 if (of_find_property(bl, "su2-feedback-curr-auto", NULL)) {
316 pdata->su2_feedback = AS3711_SU2_CURR_AUTO;
317 count++;
318 }
319 if (count != 1) {
320 ret = -EINVAL;
321 goto err_put_bl;
322 }
323
324 count = 0;
325 if (of_find_property(bl, "su2-fbprot-lx-sd4", NULL)) {
326 pdata->su2_fbprot = AS3711_SU2_LX_SD4;
327 count++;
328 }
329 if (of_find_property(bl, "su2-fbprot-gpio2", NULL)) {
330 pdata->su2_fbprot = AS3711_SU2_GPIO2;
331 count++;
332 }
333 if (of_find_property(bl, "su2-fbprot-gpio3", NULL)) {
334 pdata->su2_fbprot = AS3711_SU2_GPIO3;
335 count++;
336 }
337 if (of_find_property(bl, "su2-fbprot-gpio4", NULL)) {
338 pdata->su2_fbprot = AS3711_SU2_GPIO4;
339 count++;
340 }
341 if (count != 1) {
342 ret = -EINVAL;
343 goto err_put_bl;
344 }
345
346 count = 0;
347 if (of_find_property(bl, "su2-auto-curr1", NULL)) {
348 pdata->su2_auto_curr1 = true;
349 count++;
350 }
351 if (of_find_property(bl, "su2-auto-curr2", NULL)) {
352 pdata->su2_auto_curr2 = true;
353 count++;
354 }
355 if (of_find_property(bl, "su2-auto-curr3", NULL)) {
356 pdata->su2_auto_curr3 = true;
357 count++;
358 }
359
360
361
362
363
364 if (!count ^ (pdata->su2_feedback != AS3711_SU2_CURR_AUTO)) {
365 ret = -EINVAL;
366 goto err_put_bl;
367 }
368 }
369
370 of_node_put(bl);
371
372 return 0;
373
374err_put_bl:
375 of_node_put(bl);
376
377 return ret;
378}
379
380static int as3711_backlight_probe(struct platform_device *pdev)
381{
382 struct as3711_bl_pdata *pdata = dev_get_platdata(&pdev->dev);
383 struct as3711 *as3711 = dev_get_drvdata(pdev->dev.parent);
384 struct as3711_bl_supply *supply;
385 struct as3711_bl_data *su;
386 unsigned int max_brightness;
387 int ret;
388
389 if (!pdata) {
390 dev_err(&pdev->dev, "No platform data, exiting...\n");
391 return -ENODEV;
392 }
393
394 if (pdev->dev.parent->of_node) {
395 ret = as3711_backlight_parse_dt(&pdev->dev);
396 if (ret < 0) {
397 dev_err(&pdev->dev, "DT parsing failed: %d\n", ret);
398 return ret;
399 }
400 }
401
402 if (!pdata->su1_fb && !pdata->su2_fb) {
403 dev_err(&pdev->dev, "No framebuffer specified\n");
404 return -EINVAL;
405 }
406
407
408
409
410
411
412 if (pdata->su1_fb ||
413 pdata->su2_fbprot != AS3711_SU2_GPIO4 ||
414 pdata->su2_feedback != AS3711_SU2_CURR_AUTO) {
415 dev_warn(&pdev->dev,
416 "Attention! An untested mode has been chosen!\n"
417 "Please, review the code, enable, test, and report success:-)\n");
418 return -EINVAL;
419 }
420
421 supply = devm_kzalloc(&pdev->dev, sizeof(*supply), GFP_KERNEL);
422 if (!supply)
423 return -ENOMEM;
424
425 supply->as3711 = as3711;
426 supply->pdata = pdata;
427
428 if (pdata->su1_fb) {
429 su = &supply->su1;
430 su->type = AS3711_BL_SU1;
431
432 max_brightness = min(pdata->su1_max_uA, 31);
433 ret = as3711_bl_register(pdev, max_brightness, su);
434 if (ret < 0)
435 return ret;
436 }
437
438 if (pdata->su2_fb) {
439 su = &supply->su2;
440 su->type = AS3711_BL_SU2;
441
442 switch (pdata->su2_fbprot) {
443 case AS3711_SU2_GPIO2:
444 case AS3711_SU2_GPIO3:
445 case AS3711_SU2_GPIO4:
446 case AS3711_SU2_LX_SD4:
447 break;
448 default:
449 return -EINVAL;
450 }
451
452 switch (pdata->su2_feedback) {
453 case AS3711_SU2_VOLTAGE:
454 max_brightness = min(pdata->su2_max_uA, 31);
455 break;
456 case AS3711_SU2_CURR1:
457 case AS3711_SU2_CURR2:
458 case AS3711_SU2_CURR3:
459 case AS3711_SU2_CURR_AUTO:
460 max_brightness = min(pdata->su2_max_uA / 150, 255);
461 break;
462 default:
463 return -EINVAL;
464 }
465
466 ret = as3711_bl_init_su2(supply);
467 if (ret < 0)
468 return ret;
469
470 ret = as3711_bl_register(pdev, max_brightness, su);
471 if (ret < 0)
472 return ret;
473 }
474
475 platform_set_drvdata(pdev, supply);
476
477 return 0;
478}
479
480static struct platform_driver as3711_backlight_driver = {
481 .driver = {
482 .name = "as3711-backlight",
483 },
484 .probe = as3711_backlight_probe,
485};
486
487module_platform_driver(as3711_backlight_driver);
488
489MODULE_DESCRIPTION("Backlight Driver for AS3711 PMICs");
490MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de");
491MODULE_LICENSE("GPL");
492MODULE_ALIAS("platform:as3711-backlight");
493
