1/* Copyright (c) 2015, Sony Mobile Communications, AB.
2 *
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License version 2 and
5 * only version 2 as published by the Free Software Foundation.
6 *
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
10 * GNU General Public License for more details.
11 */
12
13#include <linux/kernel.h>
14#include <linux/leds.h>
15#include <linux/module.h>
16#include <linux/of.h>
17#include <linux/of_device.h>
18#include <linux/regmap.h>
19
20#define PM8941_WLED_REG_VAL_BASE		0x40
21#define  PM8941_WLED_REG_VAL_MAX		0xFFF
22
23#define PM8941_WLED_REG_MOD_EN			0x46
24#define  PM8941_WLED_REG_MOD_EN_BIT		BIT(7)
25#define  PM8941_WLED_REG_MOD_EN_MASK		BIT(7)
26
27#define PM8941_WLED_REG_SYNC			0x47
28#define  PM8941_WLED_REG_SYNC_MASK		0x07
29#define  PM8941_WLED_REG_SYNC_LED1		BIT(0)
30#define  PM8941_WLED_REG_SYNC_LED2		BIT(1)
31#define  PM8941_WLED_REG_SYNC_LED3		BIT(2)
32#define  PM8941_WLED_REG_SYNC_ALL		0x07
33#define  PM8941_WLED_REG_SYNC_CLEAR		0x00
34
35#define PM8941_WLED_REG_FREQ			0x4c
36#define  PM8941_WLED_REG_FREQ_MASK		0x0f
37
38#define PM8941_WLED_REG_OVP			0x4d
39#define  PM8941_WLED_REG_OVP_MASK		0x03
40
41#define PM8941_WLED_REG_BOOST			0x4e
42#define  PM8941_WLED_REG_BOOST_MASK		0x07
43
44#define PM8941_WLED_REG_SINK			0x4f
45#define  PM8941_WLED_REG_SINK_MASK		0xe0
46#define  PM8941_WLED_REG_SINK_SHFT		0x05
47
48/* Per-'string' registers below */
49#define PM8941_WLED_REG_STR_OFFSET		0x10
50
51#define PM8941_WLED_REG_STR_MOD_EN_BASE		0x60
52#define  PM8941_WLED_REG_STR_MOD_MASK		BIT(7)
53#define  PM8941_WLED_REG_STR_MOD_EN		BIT(7)
54
55#define PM8941_WLED_REG_STR_SCALE_BASE		0x62
56#define  PM8941_WLED_REG_STR_SCALE_MASK		0x1f
57
58#define PM8941_WLED_REG_STR_MOD_SRC_BASE	0x63
59#define  PM8941_WLED_REG_STR_MOD_SRC_MASK	0x01
60#define  PM8941_WLED_REG_STR_MOD_SRC_INT	0x00
61#define  PM8941_WLED_REG_STR_MOD_SRC_EXT	0x01
62
63#define PM8941_WLED_REG_STR_CABC_BASE		0x66
64#define  PM8941_WLED_REG_STR_CABC_MASK		BIT(7)
65#define  PM8941_WLED_REG_STR_CABC_EN		BIT(7)
66
67struct pm8941_wled_config {
68	u32 i_boost_limit;
69	u32 ovp;
70	u32 switch_freq;
71	u32 num_strings;
72	u32 i_limit;
73	bool cs_out_en;
74	bool ext_gen;
75	bool cabc_en;
76};
77
78struct pm8941_wled {
79	struct regmap *regmap;
80	u16 addr;
81
82	struct led_classdev cdev;
83
84	struct pm8941_wled_config cfg;
85};
86
87static int pm8941_wled_set(struct led_classdev *cdev,
88			   enum led_brightness value)
89{
90	struct pm8941_wled *wled;
91	u8 ctrl = 0;
92	u16 val;
93	int rc;
94	int i;
95
96	wled = container_of(cdev, struct pm8941_wled, cdev);
97
98	if (value != 0)
99		ctrl = PM8941_WLED_REG_MOD_EN_BIT;
100
101	val = value * PM8941_WLED_REG_VAL_MAX / LED_FULL;
102
103	rc = regmap_update_bits(wled->regmap,
104			wled->addr + PM8941_WLED_REG_MOD_EN,
105			PM8941_WLED_REG_MOD_EN_MASK, ctrl);
106	if (rc)
107		return rc;
108
109	for (i = 0; i < wled->cfg.num_strings; ++i) {
110		u8 v[2] = { val & 0xff, (val >> 8) & 0xf };
111
112		rc = regmap_bulk_write(wled->regmap,
113				wled->addr + PM8941_WLED_REG_VAL_BASE + 2 * i,
114				v, 2);
115		if (rc)
116			return rc;
117	}
118
119	rc = regmap_update_bits(wled->regmap,
120			wled->addr + PM8941_WLED_REG_SYNC,
121			PM8941_WLED_REG_SYNC_MASK, PM8941_WLED_REG_SYNC_ALL);
122	if (rc)
123		return rc;
124
125	rc = regmap_update_bits(wled->regmap,
126			wled->addr + PM8941_WLED_REG_SYNC,
127			PM8941_WLED_REG_SYNC_MASK, PM8941_WLED_REG_SYNC_CLEAR);
128	return rc;
129}
130
131static void pm8941_wled_set_brightness(struct led_classdev *cdev,
132				       enum led_brightness value)
133{
134	if (pm8941_wled_set(cdev, value)) {
135		dev_err(cdev->dev, "Unable to set brightness\n");
136		return;
137	}
138	cdev->brightness = value;
139}
140
141static int pm8941_wled_setup(struct pm8941_wled *wled)
142{
143	int rc;
144	int i;
145
146	rc = regmap_update_bits(wled->regmap,
147			wled->addr + PM8941_WLED_REG_OVP,
148			PM8941_WLED_REG_OVP_MASK, wled->cfg.ovp);
149	if (rc)
150		return rc;
151
152	rc = regmap_update_bits(wled->regmap,
153			wled->addr + PM8941_WLED_REG_BOOST,
154			PM8941_WLED_REG_BOOST_MASK, wled->cfg.i_boost_limit);
155	if (rc)
156		return rc;
157
158	rc = regmap_update_bits(wled->regmap,
159			wled->addr + PM8941_WLED_REG_FREQ,
160			PM8941_WLED_REG_FREQ_MASK, wled->cfg.switch_freq);
161	if (rc)
162		return rc;
163
164	if (wled->cfg.cs_out_en) {
165		u8 all = (BIT(wled->cfg.num_strings) - 1)
166				<< PM8941_WLED_REG_SINK_SHFT;
167
168		rc = regmap_update_bits(wled->regmap,
169				wled->addr + PM8941_WLED_REG_SINK,
170				PM8941_WLED_REG_SINK_MASK, all);
171		if (rc)
172			return rc;
173	}
174
175	for (i = 0; i < wled->cfg.num_strings; ++i) {
176		u16 addr = wled->addr + PM8941_WLED_REG_STR_OFFSET * i;
177
178		rc = regmap_update_bits(wled->regmap,
179				addr + PM8941_WLED_REG_STR_MOD_EN_BASE,
180				PM8941_WLED_REG_STR_MOD_MASK,
181				PM8941_WLED_REG_STR_MOD_EN);
182		if (rc)
183			return rc;
184
185		if (wled->cfg.ext_gen) {
186			rc = regmap_update_bits(wled->regmap,
187					addr + PM8941_WLED_REG_STR_MOD_SRC_BASE,
188					PM8941_WLED_REG_STR_MOD_SRC_MASK,
189					PM8941_WLED_REG_STR_MOD_SRC_EXT);
190			if (rc)
191				return rc;
192		}
193
194		rc = regmap_update_bits(wled->regmap,
195				addr + PM8941_WLED_REG_STR_SCALE_BASE,
196				PM8941_WLED_REG_STR_SCALE_MASK,
197				wled->cfg.i_limit);
198		if (rc)
199			return rc;
200
201		rc = regmap_update_bits(wled->regmap,
202				addr + PM8941_WLED_REG_STR_CABC_BASE,
203				PM8941_WLED_REG_STR_CABC_MASK,
204				wled->cfg.cabc_en ?
205					PM8941_WLED_REG_STR_CABC_EN : 0);
206		if (rc)
207			return rc;
208	}
209
210	return 0;
211}
212
213static const struct pm8941_wled_config pm8941_wled_config_defaults = {
214	.i_boost_limit = 3,
215	.i_limit = 20,
216	.ovp = 2,
217	.switch_freq = 5,
218	.num_strings = 0,
219	.cs_out_en = false,
220	.ext_gen = false,
221	.cabc_en = false,
222};
223
224struct pm8941_wled_var_cfg {
225	const u32 *values;
226	u32 (*fn)(u32);
227	int size;
228};
229
230static const u32 pm8941_wled_i_boost_limit_values[] = {
231	105, 385, 525, 805, 980, 1260, 1400, 1680,
232};
233
234static const struct pm8941_wled_var_cfg pm8941_wled_i_boost_limit_cfg = {
235	.values = pm8941_wled_i_boost_limit_values,
236	.size = ARRAY_SIZE(pm8941_wled_i_boost_limit_values),
237};
238
239static const u32 pm8941_wled_ovp_values[] = {
240	35, 32, 29, 27,
241};
242
243static const struct pm8941_wled_var_cfg pm8941_wled_ovp_cfg = {
244	.values = pm8941_wled_ovp_values,
245	.size = ARRAY_SIZE(pm8941_wled_ovp_values),
246};
247
248static u32 pm8941_wled_num_strings_values_fn(u32 idx)
249{
250	return idx + 1;
251}
252
253static const struct pm8941_wled_var_cfg pm8941_wled_num_strings_cfg = {
254	.fn = pm8941_wled_num_strings_values_fn,
255	.size = 3,
256};
257
258static u32 pm8941_wled_switch_freq_values_fn(u32 idx)
259{
260	return 19200 / (2 * (1 + idx));
261}
262
263static const struct pm8941_wled_var_cfg pm8941_wled_switch_freq_cfg = {
264	.fn = pm8941_wled_switch_freq_values_fn,
265	.size = 16,
266};
267
268static const struct pm8941_wled_var_cfg pm8941_wled_i_limit_cfg = {
269	.size = 26,
270};
271
272static u32 pm8941_wled_values(const struct pm8941_wled_var_cfg *cfg, u32 idx)
273{
274	if (idx >= cfg->size)
275		return UINT_MAX;
276	if (cfg->fn)
277		return cfg->fn(idx);
278	if (cfg->values)
279		return cfg->values[idx];
280	return idx;
281}
282
283static int pm8941_wled_configure(struct pm8941_wled *wled, struct device *dev)
284{
285	struct pm8941_wled_config *cfg = &wled->cfg;
286	u32 val;
287	int rc;
288	u32 c;
289	int i;
290	int j;
291
292	const struct {
293		const char *name;
294		u32 *val_ptr;
295		const struct pm8941_wled_var_cfg *cfg;
296	} u32_opts[] = {
297		{
298			"qcom,current-boost-limit",
299			&cfg->i_boost_limit,
300			.cfg = &pm8941_wled_i_boost_limit_cfg,
301		},
302		{
303			"qcom,current-limit",
304			&cfg->i_limit,
305			.cfg = &pm8941_wled_i_limit_cfg,
306		},
307		{
308			"qcom,ovp",
309			&cfg->ovp,
310			.cfg = &pm8941_wled_ovp_cfg,
311		},
312		{
313			"qcom,switching-freq",
314			&cfg->switch_freq,
315			.cfg = &pm8941_wled_switch_freq_cfg,
316		},
317		{
318			"qcom,num-strings",
319			&cfg->num_strings,
320			.cfg = &pm8941_wled_num_strings_cfg,
321		},
322	};
323	const struct {
324		const char *name;
325		bool *val_ptr;
326	} bool_opts[] = {
327		{ "qcom,cs-out", &cfg->cs_out_en, },
328		{ "qcom,ext-gen", &cfg->ext_gen, },
329		{ "qcom,cabc", &cfg->cabc_en, },
330	};
331
332	rc = of_property_read_u32(dev->of_node, "reg", &val);
333	if (rc || val > 0xffff) {
334		dev_err(dev, "invalid IO resources\n");
335		return rc ? rc : -EINVAL;
336	}
337	wled->addr = val;
338
339	rc = of_property_read_string(dev->of_node, "label", &wled->cdev.name);
340	if (rc)
341		wled->cdev.name = dev->of_node->name;
342
343	wled->cdev.default_trigger = of_get_property(dev->of_node,
344			"linux,default-trigger", NULL);
345
346	*cfg = pm8941_wled_config_defaults;
347	for (i = 0; i < ARRAY_SIZE(u32_opts); ++i) {
348		rc = of_property_read_u32(dev->of_node, u32_opts[i].name, &val);
349		if (rc == -EINVAL) {
350			continue;
351		} else if (rc) {
352			dev_err(dev, "error reading '%s'\n", u32_opts[i].name);
353			return rc;
354		}
355
356		c = UINT_MAX;
357		for (j = 0; c != val; j++) {
358			c = pm8941_wled_values(u32_opts[i].cfg, j);
359			if (c == UINT_MAX) {
360				dev_err(dev, "invalid value for '%s'\n",
361					u32_opts[i].name);
362				return -EINVAL;
363			}
364		}
365
366		dev_dbg(dev, "'%s' = %u\n", u32_opts[i].name, c);
367		*u32_opts[i].val_ptr = j;
368	}
369
370	for (i = 0; i < ARRAY_SIZE(bool_opts); ++i) {
371		if (of_property_read_bool(dev->of_node, bool_opts[i].name))
372			*bool_opts[i].val_ptr = true;
373	}
374
375	cfg->num_strings = cfg->num_strings + 1;
376
377	return 0;
378}
379
380static int pm8941_wled_probe(struct platform_device *pdev)
381{
382	struct pm8941_wled *wled;
383	struct regmap *regmap;
384	int rc;
385
386	regmap = dev_get_regmap(pdev->dev.parent, NULL);
387	if (!regmap) {
388		dev_err(&pdev->dev, "Unable to get regmap\n");
389		return -EINVAL;
390	}
391
392	wled = devm_kzalloc(&pdev->dev, sizeof(*wled), GFP_KERNEL);
393	if (!wled)
394		return -ENOMEM;
395
396	wled->regmap = regmap;
397
398	rc = pm8941_wled_configure(wled, &pdev->dev);
399	if (rc)
400		return rc;
401
402	rc = pm8941_wled_setup(wled);
403	if (rc)
404		return rc;
405
406	wled->cdev.brightness_set = pm8941_wled_set_brightness;
407
408	rc = devm_led_classdev_register(&pdev->dev, &wled->cdev);
409	if (rc)
410		return rc;
411
412	platform_set_drvdata(pdev, wled);
413
414	return 0;
415};
416
417static const struct of_device_id pm8941_wled_match_table[] = {
418	{ .compatible = "qcom,pm8941-wled" },
419	{}
420};
421MODULE_DEVICE_TABLE(of, pm8941_wled_match_table);
422
423static struct platform_driver pm8941_wled_driver = {
424	.probe = pm8941_wled_probe,
425	.driver	= {
426		.name = "pm8941-wled",
427		.of_match_table	= pm8941_wled_match_table,
428	},
429};
430
431module_platform_driver(pm8941_wled_driver);
432
433MODULE_DESCRIPTION("pm8941 wled driver");
434MODULE_LICENSE("GPL v2");
435MODULE_ALIAS("platform:pm8941-wled");
436