blob: 734a9158946b1f805a3738d9e9c31f25cf8b3314 [file] [log] [blame]
Guennadi Liakhovetskide474b5b2013-02-21 16:43:59 -08001/*
2 * AS3711 PMIC backlight driver, using DCDC Step Up Converters
3 *
4 * Copyright (C) 2012 Renesas Electronics Corporation
5 * Author: Guennadi Liakhovetski, <g.liakhovetski@gmx.de>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the version 2 of the GNU General Public License as
9 * published by the Free Software Foundation
10 */
11
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 const char *fb_name;
32 struct device *fb_dev;
33 enum as3711_bl_type type;
34 int brightness;
35 struct backlight_device *bl;
36};
37
38struct as3711_bl_supply {
39 struct as3711_bl_data su1;
40 struct as3711_bl_data su2;
41 const struct as3711_bl_pdata *pdata;
42 struct as3711 *as3711;
43};
44
45static struct as3711_bl_supply *to_supply(struct as3711_bl_data *su)
46{
47 switch (su->type) {
48 case AS3711_BL_SU1:
49 return container_of(su, struct as3711_bl_supply, su1);
50 case AS3711_BL_SU2:
51 return container_of(su, struct as3711_bl_supply, su2);
52 }
53 return NULL;
54}
55
56static int as3711_set_brightness_auto_i(struct as3711_bl_data *data,
57 unsigned int brightness)
58{
59 struct as3711_bl_supply *supply = to_supply(data);
60 struct as3711 *as3711 = supply->as3711;
61 const struct as3711_bl_pdata *pdata = supply->pdata;
62 int ret = 0;
63
64 /* Only all equal current values are supported */
65 if (pdata->su2_auto_curr1)
66 ret = regmap_write(as3711->regmap, AS3711_CURR1_VALUE,
67 brightness);
68 if (!ret && pdata->su2_auto_curr2)
69 ret = regmap_write(as3711->regmap, AS3711_CURR2_VALUE,
70 brightness);
71 if (!ret && pdata->su2_auto_curr3)
72 ret = regmap_write(as3711->regmap, AS3711_CURR3_VALUE,
73 brightness);
74
75 return ret;
76}
77
78static int as3711_set_brightness_v(struct as3711 *as3711,
79 unsigned int brightness,
80 unsigned int reg)
81{
82 if (brightness > 31)
83 return -EINVAL;
84
85 return regmap_update_bits(as3711->regmap, reg, 0xf0,
86 brightness << 4);
87}
88
89static int as3711_bl_su2_reset(struct as3711_bl_supply *supply)
90{
91 struct as3711 *as3711 = supply->as3711;
92 int ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_5,
93 3, supply->pdata->su2_fbprot);
94 if (!ret)
95 ret = regmap_update_bits(as3711->regmap,
96 AS3711_STEPUP_CONTROL_2, 1, 0);
97 if (!ret)
98 ret = regmap_update_bits(as3711->regmap,
99 AS3711_STEPUP_CONTROL_2, 1, 1);
100 return ret;
101}
102
103/*
104 * Someone with less fragile or less expensive hardware could try to simplify
105 * the brightness adjustment procedure.
106 */
107static int as3711_bl_update_status(struct backlight_device *bl)
108{
109 struct as3711_bl_data *data = bl_get_data(bl);
110 struct as3711_bl_supply *supply = to_supply(data);
111 struct as3711 *as3711 = supply->as3711;
112 int brightness = bl->props.brightness;
113 int ret = 0;
114
115 dev_dbg(&bl->dev, "%s(): brightness %u, pwr %x, blank %x, state %x\n",
116 __func__, bl->props.brightness, bl->props.power,
117 bl->props.fb_blank, bl->props.state);
118
119 if (bl->props.power != FB_BLANK_UNBLANK ||
120 bl->props.fb_blank != FB_BLANK_UNBLANK ||
121 bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
122 brightness = 0;
123
124 if (data->type == AS3711_BL_SU1) {
125 ret = as3711_set_brightness_v(as3711, brightness,
126 AS3711_STEPUP_CONTROL_1);
127 } else {
128 const struct as3711_bl_pdata *pdata = supply->pdata;
129
130 switch (pdata->su2_feedback) {
131 case AS3711_SU2_VOLTAGE:
132 ret = as3711_set_brightness_v(as3711, brightness,
133 AS3711_STEPUP_CONTROL_2);
134 break;
135 case AS3711_SU2_CURR_AUTO:
136 ret = as3711_set_brightness_auto_i(data, brightness / 4);
137 if (ret < 0)
138 return ret;
139 if (brightness) {
140 ret = as3711_bl_su2_reset(supply);
141 if (ret < 0)
142 return ret;
143 udelay(500);
144 ret = as3711_set_brightness_auto_i(data, brightness);
145 } else {
146 ret = regmap_update_bits(as3711->regmap,
147 AS3711_STEPUP_CONTROL_2, 1, 0);
148 }
149 break;
150 /* Manual one current feedback pin below */
151 case AS3711_SU2_CURR1:
152 ret = regmap_write(as3711->regmap, AS3711_CURR1_VALUE,
153 brightness);
154 break;
155 case AS3711_SU2_CURR2:
156 ret = regmap_write(as3711->regmap, AS3711_CURR2_VALUE,
157 brightness);
158 break;
159 case AS3711_SU2_CURR3:
160 ret = regmap_write(as3711->regmap, AS3711_CURR3_VALUE,
161 brightness);
162 break;
163 default:
164 ret = -EINVAL;
165 }
166 }
167 if (!ret)
168 data->brightness = brightness;
169
170 return ret;
171}
172
173static int as3711_bl_get_brightness(struct backlight_device *bl)
174{
175 struct as3711_bl_data *data = bl_get_data(bl);
176
177 return data->brightness;
178}
179
180static const struct backlight_ops as3711_bl_ops = {
181 .update_status = as3711_bl_update_status,
182 .get_brightness = as3711_bl_get_brightness,
183};
184
185static int as3711_bl_init_su2(struct as3711_bl_supply *supply)
186{
187 struct as3711 *as3711 = supply->as3711;
188 const struct as3711_bl_pdata *pdata = supply->pdata;
189 u8 ctl = 0;
190 int ret;
191
192 dev_dbg(as3711->dev, "%s(): use %u\n", __func__, pdata->su2_feedback);
193
194 /* Turn SU2 off */
195 ret = regmap_write(as3711->regmap, AS3711_STEPUP_CONTROL_2, 0);
196 if (ret < 0)
197 return ret;
198
199 switch (pdata->su2_feedback) {
200 case AS3711_SU2_VOLTAGE:
201 ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 0);
202 break;
203 case AS3711_SU2_CURR1:
204 ctl = 1;
205 ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 1);
206 break;
207 case AS3711_SU2_CURR2:
208 ctl = 4;
209 ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 2);
210 break;
211 case AS3711_SU2_CURR3:
212 ctl = 0x10;
213 ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 3);
214 break;
215 case AS3711_SU2_CURR_AUTO:
216 if (pdata->su2_auto_curr1)
217 ctl = 2;
218 if (pdata->su2_auto_curr2)
219 ctl |= 8;
220 if (pdata->su2_auto_curr3)
221 ctl |= 0x20;
222 ret = 0;
223 break;
224 default:
225 return -EINVAL;
226 }
227
228 if (!ret)
229 ret = regmap_write(as3711->regmap, AS3711_CURR_CONTROL, ctl);
230
231 return ret;
232}
233
234static int as3711_bl_register(struct platform_device *pdev,
235 unsigned int max_brightness, struct as3711_bl_data *su)
236{
237 struct backlight_properties props = {.type = BACKLIGHT_RAW,};
238 struct backlight_device *bl;
239
240 /* max tuning I = 31uA for voltage- and 38250uA for current-feedback */
241 props.max_brightness = max_brightness;
242
Jingoo Han83dedc02013-11-12 15:09:10 -0800243 bl = devm_backlight_device_register(&pdev->dev,
244 su->type == AS3711_BL_SU1 ?
Guennadi Liakhovetskide474b5b2013-02-21 16:43:59 -0800245 "as3711-su1" : "as3711-su2",
246 &pdev->dev, su,
247 &as3711_bl_ops, &props);
248 if (IS_ERR(bl)) {
249 dev_err(&pdev->dev, "failed to register backlight\n");
250 return PTR_ERR(bl);
251 }
252
253 bl->props.brightness = props.max_brightness;
254
255 backlight_update_status(bl);
256
257 su->bl = bl;
258
259 return 0;
260}
261
Guennadi Liakhovetski59eb2b52013-04-29 16:17:55 -0700262static int as3711_backlight_parse_dt(struct device *dev)
263{
264 struct as3711_bl_pdata *pdata = dev_get_platdata(dev);
265 struct device_node *bl =
266 of_find_node_by_name(dev->parent->of_node, "backlight"), *fb;
267 int ret;
268
269 if (!bl) {
270 dev_dbg(dev, "backlight node not found\n");
271 return -ENODEV;
272 }
273
274 fb = of_parse_phandle(bl, "su1-dev", 0);
275 if (fb) {
276 pdata->su1_fb = fb->full_name;
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 return ret;
283 }
284
285 fb = of_parse_phandle(bl, "su2-dev", 0);
286 if (fb) {
287 int count = 0;
288
289 pdata->su2_fb = fb->full_name;
290
291 ret = of_property_read_u32(bl, "su2-max-uA", &pdata->su2_max_uA);
292 if (pdata->su2_max_uA <= 0)
293 ret = -EINVAL;
294 if (ret < 0)
295 return ret;
296
297 if (of_find_property(bl, "su2-feedback-voltage", NULL)) {
298 pdata->su2_feedback = AS3711_SU2_VOLTAGE;
299 count++;
300 }
301 if (of_find_property(bl, "su2-feedback-curr1", NULL)) {
302 pdata->su2_feedback = AS3711_SU2_CURR1;
303 count++;
304 }
305 if (of_find_property(bl, "su2-feedback-curr2", NULL)) {
306 pdata->su2_feedback = AS3711_SU2_CURR2;
307 count++;
308 }
309 if (of_find_property(bl, "su2-feedback-curr3", NULL)) {
310 pdata->su2_feedback = AS3711_SU2_CURR3;
311 count++;
312 }
313 if (of_find_property(bl, "su2-feedback-curr-auto", NULL)) {
314 pdata->su2_feedback = AS3711_SU2_CURR_AUTO;
315 count++;
316 }
317 if (count != 1)
318 return -EINVAL;
319
320 count = 0;
321 if (of_find_property(bl, "su2-fbprot-lx-sd4", NULL)) {
322 pdata->su2_fbprot = AS3711_SU2_LX_SD4;
323 count++;
324 }
325 if (of_find_property(bl, "su2-fbprot-gpio2", NULL)) {
326 pdata->su2_fbprot = AS3711_SU2_GPIO2;
327 count++;
328 }
329 if (of_find_property(bl, "su2-fbprot-gpio3", NULL)) {
330 pdata->su2_fbprot = AS3711_SU2_GPIO3;
331 count++;
332 }
333 if (of_find_property(bl, "su2-fbprot-gpio4", NULL)) {
334 pdata->su2_fbprot = AS3711_SU2_GPIO4;
335 count++;
336 }
337 if (count != 1)
338 return -EINVAL;
339
340 count = 0;
341 if (of_find_property(bl, "su2-auto-curr1", NULL)) {
342 pdata->su2_auto_curr1 = true;
343 count++;
344 }
345 if (of_find_property(bl, "su2-auto-curr2", NULL)) {
346 pdata->su2_auto_curr2 = true;
347 count++;
348 }
349 if (of_find_property(bl, "su2-auto-curr3", NULL)) {
350 pdata->su2_auto_curr3 = true;
351 count++;
352 }
353
354 /*
355 * At least one su2-auto-curr* must be specified iff
356 * AS3711_SU2_CURR_AUTO is used
357 */
358 if (!count ^ (pdata->su2_feedback != AS3711_SU2_CURR_AUTO))
359 return -EINVAL;
360 }
361
362 return 0;
363}
364
Guennadi Liakhovetskide474b5b2013-02-21 16:43:59 -0800365static int as3711_backlight_probe(struct platform_device *pdev)
366{
367 struct as3711_bl_pdata *pdata = dev_get_platdata(&pdev->dev);
368 struct as3711 *as3711 = dev_get_drvdata(pdev->dev.parent);
369 struct as3711_bl_supply *supply;
370 struct as3711_bl_data *su;
371 unsigned int max_brightness;
372 int ret;
373
Guennadi Liakhovetski59eb2b52013-04-29 16:17:55 -0700374 if (!pdata) {
Guennadi Liakhovetskide474b5b2013-02-21 16:43:59 -0800375 dev_err(&pdev->dev, "No platform data, exiting...\n");
376 return -ENODEV;
377 }
378
Guennadi Liakhovetski59eb2b52013-04-29 16:17:55 -0700379 if (pdev->dev.parent->of_node) {
380 ret = as3711_backlight_parse_dt(&pdev->dev);
381 if (ret < 0) {
382 dev_err(&pdev->dev, "DT parsing failed: %d\n", ret);
383 return ret;
384 }
385 }
386
387 if (!pdata->su1_fb && !pdata->su2_fb) {
388 dev_err(&pdev->dev, "No framebuffer specified\n");
389 return -EINVAL;
390 }
391
Guennadi Liakhovetskide474b5b2013-02-21 16:43:59 -0800392 /*
393 * Due to possible hardware damage I chose to block all modes,
394 * unsupported on my hardware. Anyone, wishing to use any of those modes
395 * will have to first review the code, then activate and test it.
396 */
397 if (pdata->su1_fb ||
398 pdata->su2_fbprot != AS3711_SU2_GPIO4 ||
399 pdata->su2_feedback != AS3711_SU2_CURR_AUTO) {
400 dev_warn(&pdev->dev,
401 "Attention! An untested mode has been chosen!\n"
402 "Please, review the code, enable, test, and report success:-)\n");
403 return -EINVAL;
404 }
405
406 supply = devm_kzalloc(&pdev->dev, sizeof(*supply), GFP_KERNEL);
407 if (!supply)
408 return -ENOMEM;
409
410 supply->as3711 = as3711;
411 supply->pdata = pdata;
412
413 if (pdata->su1_fb) {
414 su = &supply->su1;
415 su->fb_name = pdata->su1_fb;
416 su->type = AS3711_BL_SU1;
417
418 max_brightness = min(pdata->su1_max_uA, 31);
419 ret = as3711_bl_register(pdev, max_brightness, su);
420 if (ret < 0)
421 return ret;
422 }
423
424 if (pdata->su2_fb) {
425 su = &supply->su2;
426 su->fb_name = pdata->su2_fb;
427 su->type = AS3711_BL_SU2;
428
429 switch (pdata->su2_fbprot) {
430 case AS3711_SU2_GPIO2:
431 case AS3711_SU2_GPIO3:
432 case AS3711_SU2_GPIO4:
433 case AS3711_SU2_LX_SD4:
434 break;
435 default:
Jingoo Han83dedc02013-11-12 15:09:10 -0800436 return -EINVAL;
Guennadi Liakhovetskide474b5b2013-02-21 16:43:59 -0800437 }
438
439 switch (pdata->su2_feedback) {
440 case AS3711_SU2_VOLTAGE:
441 max_brightness = min(pdata->su2_max_uA, 31);
442 break;
443 case AS3711_SU2_CURR1:
444 case AS3711_SU2_CURR2:
445 case AS3711_SU2_CURR3:
446 case AS3711_SU2_CURR_AUTO:
447 max_brightness = min(pdata->su2_max_uA / 150, 255);
448 break;
449 default:
Jingoo Han83dedc02013-11-12 15:09:10 -0800450 return -EINVAL;
Guennadi Liakhovetskide474b5b2013-02-21 16:43:59 -0800451 }
452
453 ret = as3711_bl_init_su2(supply);
454 if (ret < 0)
455 return ret;
456
457 ret = as3711_bl_register(pdev, max_brightness, su);
458 if (ret < 0)
Jingoo Han83dedc02013-11-12 15:09:10 -0800459 return ret;
Guennadi Liakhovetskide474b5b2013-02-21 16:43:59 -0800460 }
461
462 platform_set_drvdata(pdev, supply);
463
464 return 0;
Guennadi Liakhovetskide474b5b2013-02-21 16:43:59 -0800465}
466
467static struct platform_driver as3711_backlight_driver = {
468 .driver = {
469 .name = "as3711-backlight",
Guennadi Liakhovetskide474b5b2013-02-21 16:43:59 -0800470 },
471 .probe = as3711_backlight_probe,
Guennadi Liakhovetskide474b5b2013-02-21 16:43:59 -0800472};
473
474module_platform_driver(as3711_backlight_driver);
475
476MODULE_DESCRIPTION("Backlight Driver for AS3711 PMICs");
477MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de");
478MODULE_LICENSE("GPL");
479MODULE_ALIAS("platform:as3711-backlight");