summaryrefslogtreecommitdiffstats
path: root/drivers/power/avs/rockchip-io-domain.c
blob: 2e300028f0f774d4662546ba0bd88cce32465cf2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
/*
 * Rockchip IO Voltage Domain driver
 *
 * Copyright 2014 MundoReader S.L.
 * Copyright 2014 Google, Inc.
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/mfd/syscon.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>

#define MAX_SUPPLIES		16

/*
 * The max voltage for 1.8V and 3.3V come from the Rockchip datasheet under
 * "Recommended Operating Conditions" for "Digital GPIO".   When the typical
 * is 3.3V the max is 3.6V.  When the typical is 1.8V the max is 1.98V.
 *
 * They are used like this:
 * - If the voltage on a rail is above the "1.8" voltage (1.98V) we'll tell the
 *   SoC we're at 3.3.
 * - If the voltage on a rail is above the "3.3" voltage (3.6V) we'll consider
 *   that to be an error.
 */
#define MAX_VOLTAGE_1_8		1980000
#define MAX_VOLTAGE_3_3		3600000

#define RK3288_SOC_CON2			0x24c
#define RK3288_SOC_CON2_FLASH0		BIT(7)
#define RK3288_SOC_FLASH_SUPPLY_NUM	2

#define RK3368_SOC_CON15		0x43c
#define RK3368_SOC_CON15_FLASH0		BIT(14)
#define RK3368_SOC_FLASH_SUPPLY_NUM	2

struct rockchip_iodomain;

/**
 * @supplies: voltage settings matching the register bits.
 */
struct rockchip_iodomain_soc_data {
	int grf_offset;
	const char *supply_names[MAX_SUPPLIES];
	void (*init)(struct rockchip_iodomain *iod);
};

struct rockchip_iodomain_supply {
	struct rockchip_iodomain *iod;
	struct regulator *reg;
	struct notifier_block nb;
	int idx;
};

struct rockchip_iodomain {
	struct device *dev;
	struct regmap *grf;
	struct rockchip_iodomain_soc_data *soc_data;
	struct rockchip_iodomain_supply supplies[MAX_SUPPLIES];
};

static int rockchip_iodomain_write(struct rockchip_iodomain_supply *supply,
				   int uV)
{
	struct rockchip_iodomain *iod = supply->iod;
	u32 val;
	int ret;

	/* set value bit */
	val = (uV > MAX_VOLTAGE_1_8) ? 0 : 1;
	val <<= supply->idx;

	/* apply hiword-mask */
	val |= (BIT(supply->idx) << 16);

	ret = regmap_write(iod->grf, iod->soc_data->grf_offset, val);
	if (ret)
		dev_err(iod->dev, "Couldn't write to GRF\n");

	return ret;
}

static int rockchip_iodomain_notify(struct notifier_block *nb,
				    unsigned long event,
				    void *data)
{
	struct rockchip_iodomain_supply *supply =
			container_of(nb, struct rockchip_iodomain_supply, nb);
	int uV;
	int ret;

	/*
	 * According to Rockchip it's important to keep the SoC IO domain
	 * higher than (or equal to) the external voltage.  That means we need
	 * to change it before external voltage changes happen in the case
	 * of an increase.
	 *
	 * Note that in the "pre" change we pick the max possible voltage that
	 * the regulator might end up at (the client requests a range and we
	 * don't know for certain the exact voltage).  Right now we rely on the
	 * slop in MAX_VOLTAGE_1_8 and MAX_VOLTAGE_3_3 to save us if clients
	 * request something like a max of 3.6V when they really want 3.3V.
	 * We could attempt to come up with better rules if this fails.
	 */
	if (event & REGULATOR_EVENT_PRE_VOLTAGE_CHANGE) {
		struct pre_voltage_change_data *pvc_data = data;

		uV = max_t(unsigned long, pvc_data->old_uV, pvc_data->max_uV);
	} else if (event & (REGULATOR_EVENT_VOLTAGE_CHANGE |
			    REGULATOR_EVENT_ABORT_VOLTAGE_CHANGE)) {
		uV = (unsigned long)data;
	} else {
		return NOTIFY_OK;
	}

	dev_dbg(supply->iod->dev, "Setting to %d\n", uV);

	if (uV > MAX_VOLTAGE_3_3) {
		dev_err(supply->iod->dev, "Voltage too high: %d\n", uV);

		if (event == REGULATOR_EVENT_PRE_VOLTAGE_CHANGE)
			return NOTIFY_BAD;
	}

	ret = rockchip_iodomain_write(supply, uV);
	if (ret && event == REGULATOR_EVENT_PRE_VOLTAGE_CHANGE)
		return NOTIFY_BAD;

	dev_info(supply->iod->dev, "Setting to %d done\n", uV);
	return NOTIFY_OK;
}

static void rk3288_iodomain_init(struct rockchip_iodomain *iod)
{
	int ret;
	u32 val;

	/* if no flash supply we should leave things alone */
	if (!iod->supplies[RK3288_SOC_FLASH_SUPPLY_NUM].reg)
		return;

	/*
	 * set flash0 iodomain to also use this framework
	 * instead of a special gpio.
	 */
	val = RK3288_SOC_CON2_FLASH0 | (RK3288_SOC_CON2_FLASH0 << 16);
	ret = regmap_write(iod->grf, RK3288_SOC_CON2, val);
	if (ret < 0)
		dev_warn(iod->dev, "couldn't update flash0 ctrl\n");
}

static void rk3368_iodomain_init(struct rockchip_iodomain *iod)
{
	int ret;
	u32 val;

	/* if no flash supply we should leave things alone */
	if (!iod->supplies[RK3368_SOC_FLASH_SUPPLY_NUM].reg)
		return;

	/*
	 * set flash0 iodomain to also use this framework
	 * instead of a special gpio.
	 */
	val = RK3368_SOC_CON15_FLASH0 | (RK3368_SOC_CON15_FLASH0 << 16);
	ret = regmap_write(iod->grf, RK3368_SOC_CON15, val);
	if (ret < 0)
		dev_warn(iod->dev, "couldn't update flash0 ctrl\n");
}

/*
 * On the rk3188 the io-domains are handled by a shared register with the
 * lower 8 bits being still being continuing drive-strength settings.
 */
static const struct rockchip_iodomain_soc_data soc_data_rk3188 = {
	.grf_offset = 0x104,
	.supply_names = {
		NULL,
		NULL,
		NULL,
		NULL,
		NULL,
		NULL,
		NULL,
		NULL,
		"ap0",
		"ap1",
		"cif",
		"flash",
		"vccio0",
		"vccio1",
		"lcdc0",
		"lcdc1",
	},
};

static const struct rockchip_iodomain_soc_data soc_data_rk3288 = {
	.grf_offset = 0x380,
	.supply_names = {
		"lcdc",		/* LCDC_VDD */
		"dvp",		/* DVPIO_VDD */
		"flash0",	/* FLASH0_VDD (emmc) */
		"flash1",	/* FLASH1_VDD (sdio1) */
		"wifi",		/* APIO3_VDD  (sdio0) */
		"bb",		/* APIO5_VDD */
		"audio",	/* APIO4_VDD */
		"sdcard",	/* SDMMC0_VDD (sdmmc) */
		"gpio30",	/* APIO1_VDD */
		"gpio1830",	/* APIO2_VDD */
	},
	.init = rk3288_iodomain_init,
};

static const struct rockchip_iodomain_soc_data soc_data_rk3368 = {
	.grf_offset = 0x900,
	.supply_names = {
		NULL,		/* reserved */
		"dvp",		/* DVPIO_VDD */
		"flash0",	/* FLASH0_VDD (emmc) */
		"wifi",		/* APIO2_VDD (sdio0) */
		NULL,
		"audio",	/* APIO3_VDD */
		"sdcard",	/* SDMMC0_VDD (sdmmc) */
		"gpio30",	/* APIO1_VDD */
		"gpio1830",	/* APIO4_VDD (gpujtag) */
	},
	.init = rk3368_iodomain_init,
};

static const struct rockchip_iodomain_soc_data soc_data_rk3368_pmu = {
	.grf_offset = 0x100,
	.supply_names = {
		NULL,
		NULL,
		NULL,
		NULL,
		"pmu",	        /*PMU IO domain*/
		"vop",	        /*LCDC IO domain*/
	},
};

static const struct of_device_id rockchip_iodomain_match[] = {
	{
		.compatible = "rockchip,rk3188-io-voltage-domain",
		.data = (void *)&soc_data_rk3188
	},
	{
		.compatible = "rockchip,rk3288-io-voltage-domain",
		.data = (void *)&soc_data_rk3288
	},
	{
		.compatible = "rockchip,rk3368-io-voltage-domain",
		.data = (void *)&soc_data_rk3368
	},
	{
		.compatible = "rockchip,rk3368-pmu-io-voltage-domain",
		.data = (void *)&soc_data_rk3368_pmu
	},
	{ /* sentinel */ },
};

static int rockchip_iodomain_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	const struct of_device_id *match;
	struct rockchip_iodomain *iod;
	int i, ret = 0;

	if (!np)
		return -ENODEV;

	iod = devm_kzalloc(&pdev->dev, sizeof(*iod), GFP_KERNEL);
	if (!iod)
		return -ENOMEM;

	iod->dev = &pdev->dev;
	platform_set_drvdata(pdev, iod);

	match = of_match_node(rockchip_iodomain_match, np);
	iod->soc_data = (struct rockchip_iodomain_soc_data *)match->data;

	iod->grf = syscon_regmap_lookup_by_phandle(np, "rockchip,grf");
	if (IS_ERR(iod->grf)) {
		dev_err(&pdev->dev, "couldn't find grf regmap\n");
		return PTR_ERR(iod->grf);
	}

	for (i = 0; i < MAX_SUPPLIES; i++) {
		const char *supply_name = iod->soc_data->supply_names[i];
		struct rockchip_iodomain_supply *supply = &iod->supplies[i];
		struct regulator *reg;
		int uV;

		if (!supply_name)
			continue;

		reg = devm_regulator_get_optional(iod->dev, supply_name);
		if (IS_ERR(reg)) {
			ret = PTR_ERR(reg);

			/* If a supply wasn't specified, that's OK */
			if (ret == -ENODEV)
				continue;
			else if (ret != -EPROBE_DEFER)
				dev_err(iod->dev, "couldn't get regulator %s\n",
					supply_name);
			goto unreg_notify;
		}

		/* set initial correct value */
		uV = regulator_get_voltage(reg);

		/* must be a regulator we can get the voltage of */
		if (uV < 0) {
			dev_err(iod->dev, "Can't determine voltage: %s\n",
				supply_name);
			goto unreg_notify;
		}

		if (uV > MAX_VOLTAGE_3_3) {
			dev_crit(iod->dev,
				 "%d uV is too high. May damage SoC!\n",
				 uV);
			ret = -EINVAL;
			goto unreg_notify;
		}

		/* setup our supply */
		supply->idx = i;
		supply->iod = iod;
		supply->reg = reg;
		supply->nb.notifier_call = rockchip_iodomain_notify;

		ret = rockchip_iodomain_write(supply, uV);
		if (ret) {
			supply->reg = NULL;
			goto unreg_notify;
		}

		/* register regulator notifier */
		ret = regulator_register_notifier(reg, &supply->nb);
		if (ret) {
			dev_err(&pdev->dev,
				"regulator notifier request failed\n");
			supply->reg = NULL;
			goto unreg_notify;
		}
	}

	if (iod->soc_data->init)
		iod->soc_data->init(iod);

	return 0;

unreg_notify:
	for (i = MAX_SUPPLIES - 1; i >= 0; i--) {
		struct rockchip_iodomain_supply *io_supply = &iod->supplies[i];

		if (io_supply->reg)
			regulator_unregister_notifier(io_supply->reg,
						      &io_supply->nb);
	}

	return ret;
}

static int rockchip_iodomain_remove(struct platform_device *pdev)
{
	struct rockchip_iodomain *iod = platform_get_drvdata(pdev);
	int i;

	for (i = MAX_SUPPLIES - 1; i >= 0; i--) {
		struct rockchip_iodomain_supply *io_supply = &iod->supplies[i];

		if (io_supply->reg)
			regulator_unregister_notifier(io_supply->reg,
						      &io_supply->nb);
	}

	return 0;
}

static struct platform_driver rockchip_iodomain_driver = {
	.probe   = rockchip_iodomain_probe,
	.remove  = rockchip_iodomain_remove,
	.driver  = {
		.name  = "rockchip-iodomain",
		.of_match_table = rockchip_iodomain_match,
	},
};

module_platform_driver(rockchip_iodomain_driver);

MODULE_DESCRIPTION("Rockchip IO-domain driver");
MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
MODULE_AUTHOR("Doug Anderson <dianders@chromium.org>");
MODULE_LICENSE("GPL v2");