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13#include <linux/kernel.h>
14#include <linux/backlight.h>
15#include <linux/module.h>
16#include <linux/of.h>
17#include <linux/of_device.h>
18#include <linux/regmap.h>
19
20
21#define PM8941_WLED_DEFAULT_BRIGHTNESS 2048
22
23#define PM8941_WLED_REG_VAL_BASE 0x40
24#define PM8941_WLED_REG_VAL_MAX 0xFFF
25
26#define PM8941_WLED_REG_MOD_EN 0x46
27#define PM8941_WLED_REG_MOD_EN_BIT BIT(7)
28#define PM8941_WLED_REG_MOD_EN_MASK BIT(7)
29
30#define PM8941_WLED_REG_SYNC 0x47
31#define PM8941_WLED_REG_SYNC_MASK 0x07
32#define PM8941_WLED_REG_SYNC_LED1 BIT(0)
33#define PM8941_WLED_REG_SYNC_LED2 BIT(1)
34#define PM8941_WLED_REG_SYNC_LED3 BIT(2)
35#define PM8941_WLED_REG_SYNC_ALL 0x07
36#define PM8941_WLED_REG_SYNC_CLEAR 0x00
37
38#define PM8941_WLED_REG_FREQ 0x4c
39#define PM8941_WLED_REG_FREQ_MASK 0x0f
40
41#define PM8941_WLED_REG_OVP 0x4d
42#define PM8941_WLED_REG_OVP_MASK 0x03
43
44#define PM8941_WLED_REG_BOOST 0x4e
45#define PM8941_WLED_REG_BOOST_MASK 0x07
46
47#define PM8941_WLED_REG_SINK 0x4f
48#define PM8941_WLED_REG_SINK_MASK 0xe0
49#define PM8941_WLED_REG_SINK_SHFT 0x05
50
51
52#define PM8941_WLED_REG_STR_OFFSET 0x10
53
54#define PM8941_WLED_REG_STR_MOD_EN_BASE 0x60
55#define PM8941_WLED_REG_STR_MOD_MASK BIT(7)
56#define PM8941_WLED_REG_STR_MOD_EN BIT(7)
57
58#define PM8941_WLED_REG_STR_SCALE_BASE 0x62
59#define PM8941_WLED_REG_STR_SCALE_MASK 0x1f
60
61#define PM8941_WLED_REG_STR_MOD_SRC_BASE 0x63
62#define PM8941_WLED_REG_STR_MOD_SRC_MASK 0x01
63#define PM8941_WLED_REG_STR_MOD_SRC_INT 0x00
64#define PM8941_WLED_REG_STR_MOD_SRC_EXT 0x01
65
66#define PM8941_WLED_REG_STR_CABC_BASE 0x66
67#define PM8941_WLED_REG_STR_CABC_MASK BIT(7)
68#define PM8941_WLED_REG_STR_CABC_EN BIT(7)
69
70struct pm8941_wled_config {
71 u32 i_boost_limit;
72 u32 ovp;
73 u32 switch_freq;
74 u32 num_strings;
75 u32 i_limit;
76 bool cs_out_en;
77 bool ext_gen;
78 bool cabc_en;
79};
80
81struct pm8941_wled {
82 const char *name;
83 struct regmap *regmap;
84 u16 addr;
85
86 struct pm8941_wled_config cfg;
87};
88
89static int pm8941_wled_update_status(struct backlight_device *bl)
90{
91 struct pm8941_wled *wled = bl_get_data(bl);
92 u16 val = bl->props.brightness;
93 u8 ctrl = 0;
94 int rc;
95 int i;
96
97 if (bl->props.power != FB_BLANK_UNBLANK ||
98 bl->props.fb_blank != FB_BLANK_UNBLANK ||
99 bl->props.state & BL_CORE_FBBLANK)
100 val = 0;
101
102 if (val != 0)
103 ctrl = PM8941_WLED_REG_MOD_EN_BIT;
104
105 rc = regmap_update_bits(wled->regmap,
106 wled->addr + PM8941_WLED_REG_MOD_EN,
107 PM8941_WLED_REG_MOD_EN_MASK, ctrl);
108 if (rc)
109 return rc;
110
111 for (i = 0; i < wled->cfg.num_strings; ++i) {
112 u8 v[2] = { val & 0xff, (val >> 8) & 0xf };
113
114 rc = regmap_bulk_write(wled->regmap,
115 wled->addr + PM8941_WLED_REG_VAL_BASE + 2 * i,
116 v, 2);
117 if (rc)
118 return rc;
119 }
120
121 rc = regmap_update_bits(wled->regmap,
122 wled->addr + PM8941_WLED_REG_SYNC,
123 PM8941_WLED_REG_SYNC_MASK, PM8941_WLED_REG_SYNC_ALL);
124 if (rc)
125 return rc;
126
127 rc = regmap_update_bits(wled->regmap,
128 wled->addr + PM8941_WLED_REG_SYNC,
129 PM8941_WLED_REG_SYNC_MASK, PM8941_WLED_REG_SYNC_CLEAR);
130 return rc;
131}
132
133static int pm8941_wled_setup(struct pm8941_wled *wled)
134{
135 int rc;
136 int i;
137
138 rc = regmap_update_bits(wled->regmap,
139 wled->addr + PM8941_WLED_REG_OVP,
140 PM8941_WLED_REG_OVP_MASK, wled->cfg.ovp);
141 if (rc)
142 return rc;
143
144 rc = regmap_update_bits(wled->regmap,
145 wled->addr + PM8941_WLED_REG_BOOST,
146 PM8941_WLED_REG_BOOST_MASK, wled->cfg.i_boost_limit);
147 if (rc)
148 return rc;
149
150 rc = regmap_update_bits(wled->regmap,
151 wled->addr + PM8941_WLED_REG_FREQ,
152 PM8941_WLED_REG_FREQ_MASK, wled->cfg.switch_freq);
153 if (rc)
154 return rc;
155
156 if (wled->cfg.cs_out_en) {
157 u8 all = (BIT(wled->cfg.num_strings) - 1)
158 << PM8941_WLED_REG_SINK_SHFT;
159
160 rc = regmap_update_bits(wled->regmap,
161 wled->addr + PM8941_WLED_REG_SINK,
162 PM8941_WLED_REG_SINK_MASK, all);
163 if (rc)
164 return rc;
165 }
166
167 for (i = 0; i < wled->cfg.num_strings; ++i) {
168 u16 addr = wled->addr + PM8941_WLED_REG_STR_OFFSET * i;
169
170 rc = regmap_update_bits(wled->regmap,
171 addr + PM8941_WLED_REG_STR_MOD_EN_BASE,
172 PM8941_WLED_REG_STR_MOD_MASK,
173 PM8941_WLED_REG_STR_MOD_EN);
174 if (rc)
175 return rc;
176
177 if (wled->cfg.ext_gen) {
178 rc = regmap_update_bits(wled->regmap,
179 addr + PM8941_WLED_REG_STR_MOD_SRC_BASE,
180 PM8941_WLED_REG_STR_MOD_SRC_MASK,
181 PM8941_WLED_REG_STR_MOD_SRC_EXT);
182 if (rc)
183 return rc;
184 }
185
186 rc = regmap_update_bits(wled->regmap,
187 addr + PM8941_WLED_REG_STR_SCALE_BASE,
188 PM8941_WLED_REG_STR_SCALE_MASK,
189 wled->cfg.i_limit);
190 if (rc)
191 return rc;
192
193 rc = regmap_update_bits(wled->regmap,
194 addr + PM8941_WLED_REG_STR_CABC_BASE,
195 PM8941_WLED_REG_STR_CABC_MASK,
196 wled->cfg.cabc_en ?
197 PM8941_WLED_REG_STR_CABC_EN : 0);
198 if (rc)
199 return rc;
200 }
201
202 return 0;
203}
204
205static const struct pm8941_wled_config pm8941_wled_config_defaults = {
206 .i_boost_limit = 3,
207 .i_limit = 20,
208 .ovp = 2,
209 .switch_freq = 5,
210 .num_strings = 0,
211 .cs_out_en = false,
212 .ext_gen = false,
213 .cabc_en = false,
214};
215
216struct pm8941_wled_var_cfg {
217 const u32 *values;
218 u32 (*fn)(u32);
219 int size;
220};
221
222static const u32 pm8941_wled_i_boost_limit_values[] = {
223 105, 385, 525, 805, 980, 1260, 1400, 1680,
224};
225
226static const struct pm8941_wled_var_cfg pm8941_wled_i_boost_limit_cfg = {
227 .values = pm8941_wled_i_boost_limit_values,
228 .size = ARRAY_SIZE(pm8941_wled_i_boost_limit_values),
229};
230
231static const u32 pm8941_wled_ovp_values[] = {
232 35, 32, 29, 27,
233};
234
235static const struct pm8941_wled_var_cfg pm8941_wled_ovp_cfg = {
236 .values = pm8941_wled_ovp_values,
237 .size = ARRAY_SIZE(pm8941_wled_ovp_values),
238};
239
240static u32 pm8941_wled_num_strings_values_fn(u32 idx)
241{
242 return idx + 1;
243}
244
245static const struct pm8941_wled_var_cfg pm8941_wled_num_strings_cfg = {
246 .fn = pm8941_wled_num_strings_values_fn,
247 .size = 3,
248};
249
250static u32 pm8941_wled_switch_freq_values_fn(u32 idx)
251{
252 return 19200 / (2 * (1 + idx));
253}
254
255static const struct pm8941_wled_var_cfg pm8941_wled_switch_freq_cfg = {
256 .fn = pm8941_wled_switch_freq_values_fn,
257 .size = 16,
258};
259
260static const struct pm8941_wled_var_cfg pm8941_wled_i_limit_cfg = {
261 .size = 26,
262};
263
264static u32 pm8941_wled_values(const struct pm8941_wled_var_cfg *cfg, u32 idx)
265{
266 if (idx >= cfg->size)
267 return UINT_MAX;
268 if (cfg->fn)
269 return cfg->fn(idx);
270 if (cfg->values)
271 return cfg->values[idx];
272 return idx;
273}
274
275static int pm8941_wled_configure(struct pm8941_wled *wled, struct device *dev)
276{
277 struct pm8941_wled_config *cfg = &wled->cfg;
278 u32 val;
279 int rc;
280 u32 c;
281 int i;
282 int j;
283
284 const struct {
285 const char *name;
286 u32 *val_ptr;
287 const struct pm8941_wled_var_cfg *cfg;
288 } u32_opts[] = {
289 {
290 "qcom,current-boost-limit",
291 &cfg->i_boost_limit,
292 .cfg = &pm8941_wled_i_boost_limit_cfg,
293 },
294 {
295 "qcom,current-limit",
296 &cfg->i_limit,
297 .cfg = &pm8941_wled_i_limit_cfg,
298 },
299 {
300 "qcom,ovp",
301 &cfg->ovp,
302 .cfg = &pm8941_wled_ovp_cfg,
303 },
304 {
305 "qcom,switching-freq",
306 &cfg->switch_freq,
307 .cfg = &pm8941_wled_switch_freq_cfg,
308 },
309 {
310 "qcom,num-strings",
311 &cfg->num_strings,
312 .cfg = &pm8941_wled_num_strings_cfg,
313 },
314 };
315 const struct {
316 const char *name;
317 bool *val_ptr;
318 } bool_opts[] = {
319 { "qcom,cs-out", &cfg->cs_out_en, },
320 { "qcom,ext-gen", &cfg->ext_gen, },
321 { "qcom,cabc", &cfg->cabc_en, },
322 };
323
324 rc = of_property_read_u32(dev->of_node, "reg", &val);
325 if (rc || val > 0xffff) {
326 dev_err(dev, "invalid IO resources\n");
327 return rc ? rc : -EINVAL;
328 }
329 wled->addr = val;
330
331 rc = of_property_read_string(dev->of_node, "label", &wled->name);
332 if (rc)
333 wled->name = dev->of_node->name;
334
335 *cfg = pm8941_wled_config_defaults;
336 for (i = 0; i < ARRAY_SIZE(u32_opts); ++i) {
337 rc = of_property_read_u32(dev->of_node, u32_opts[i].name, &val);
338 if (rc == -EINVAL) {
339 continue;
340 } else if (rc) {
341 dev_err(dev, "error reading '%s'\n", u32_opts[i].name);
342 return rc;
343 }
344
345 c = UINT_MAX;
346 for (j = 0; c != val; j++) {
347 c = pm8941_wled_values(u32_opts[i].cfg, j);
348 if (c == UINT_MAX) {
349 dev_err(dev, "invalid value for '%s'\n",
350 u32_opts[i].name);
351 return -EINVAL;
352 }
353 }
354
355 dev_dbg(dev, "'%s' = %u\n", u32_opts[i].name, c);
356 *u32_opts[i].val_ptr = j;
357 }
358
359 for (i = 0; i < ARRAY_SIZE(bool_opts); ++i) {
360 if (of_property_read_bool(dev->of_node, bool_opts[i].name))
361 *bool_opts[i].val_ptr = true;
362 }
363
364 cfg->num_strings = cfg->num_strings + 1;
365
366 return 0;
367}
368
369static const struct backlight_ops pm8941_wled_ops = {
370 .update_status = pm8941_wled_update_status,
371};
372
373static int pm8941_wled_probe(struct platform_device *pdev)
374{
375 struct backlight_properties props;
376 struct backlight_device *bl;
377 struct pm8941_wled *wled;
378 struct regmap *regmap;
379 u32 val;
380 int rc;
381
382 regmap = dev_get_regmap(pdev->dev.parent, NULL);
383 if (!regmap) {
384 dev_err(&pdev->dev, "Unable to get regmap\n");
385 return -EINVAL;
386 }
387
388 wled = devm_kzalloc(&pdev->dev, sizeof(*wled), GFP_KERNEL);
389 if (!wled)
390 return -ENOMEM;
391
392 wled->regmap = regmap;
393
394 rc = pm8941_wled_configure(wled, &pdev->dev);
395 if (rc)
396 return rc;
397
398 rc = pm8941_wled_setup(wled);
399 if (rc)
400 return rc;
401
402 val = PM8941_WLED_DEFAULT_BRIGHTNESS;
403 of_property_read_u32(pdev->dev.of_node, "default-brightness", &val);
404
405 memset(&props, 0, sizeof(struct backlight_properties));
406 props.type = BACKLIGHT_RAW;
407 props.brightness = val;
408 props.max_brightness = PM8941_WLED_REG_VAL_MAX;
409 bl = devm_backlight_device_register(&pdev->dev, wled->name,
410 &pdev->dev, wled,
411 &pm8941_wled_ops, &props);
412 return PTR_ERR_OR_ZERO(bl);
413};
414
415static const struct of_device_id pm8941_wled_match_table[] = {
416 { .compatible = "qcom,pm8941-wled" },
417 {}
418};
419MODULE_DEVICE_TABLE(of, pm8941_wled_match_table);
420
421static struct platform_driver pm8941_wled_driver = {
422 .probe = pm8941_wled_probe,
423 .driver = {
424 .name = "pm8941-wled",
425 .of_match_table = pm8941_wled_match_table,
426 },
427};
428
429module_platform_driver(pm8941_wled_driver);
430
431MODULE_DESCRIPTION("pm8941 wled driver");
432MODULE_LICENSE("GPL v2");
433
