aboutsummaryrefslogtreecommitdiff
path: root/drivers/rtc/rtc-sunplus.c
blob: e8e2ab1103fc049fcfe56aa8e629129847bb6254 (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
// SPDX-License-Identifier: GPL-2.0

/*
 * The RTC driver for Sunplus	SP7021
 *
 * Copyright (C) 2019 Sunplus Technology Inc., All rights reseerved.
 */

#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/ktime.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/reset.h>
#include <linux/rtc.h>

#define RTC_REG_NAME			"rtc"

#define RTC_CTRL			0x40
#define TIMER_FREEZE_MASK_BIT		BIT(5 + 16)
#define TIMER_FREEZE			BIT(5)
#define DIS_SYS_RST_RTC_MASK_BIT	BIT(4 + 16)
#define DIS_SYS_RST_RTC			BIT(4)
#define RTC32K_MODE_RESET_MASK_BIT	BIT(3 + 16)
#define RTC32K_MODE_RESET		BIT(3)
#define ALARM_EN_OVERDUE_MASK_BIT	BIT(2 + 16)
#define ALARM_EN_OVERDUE		BIT(2)
#define ALARM_EN_PMC_MASK_BIT		BIT(1 + 16)
#define ALARM_EN_PMC			BIT(1)
#define ALARM_EN_MASK_BIT		BIT(0 + 16)
#define ALARM_EN			BIT(0)
#define RTC_TIMER_OUT			0x44
#define RTC_DIVIDER			0x48
#define RTC_TIMER_SET			0x4c
#define RTC_ALARM_SET			0x50
#define RTC_USER_DATA			0x54
#define RTC_RESET_RECORD		0x58
#define RTC_BATT_CHARGE_CTRL		0x5c
#define BAT_CHARGE_RSEL_MASK_BIT	GENMASK(3 + 16, 2 + 16)
#define BAT_CHARGE_RSEL_MASK		GENMASK(3, 2)
#define BAT_CHARGE_RSEL_2K_OHM		FIELD_PREP(BAT_CHARGE_RSEL_MASK, 0)
#define BAT_CHARGE_RSEL_250_OHM		FIELD_PREP(BAT_CHARGE_RSEL_MASK, 1)
#define BAT_CHARGE_RSEL_50_OHM		FIELD_PREP(BAT_CHARGE_RSEL_MASK, 2)
#define BAT_CHARGE_RSEL_0_OHM		FIELD_PREP(BAT_CHARGE_RSEL_MASK, 3)
#define BAT_CHARGE_DSEL_MASK_BIT	BIT(1 + 16)
#define BAT_CHARGE_DSEL_MASK		GENMASK(1, 1)
#define BAT_CHARGE_DSEL_ON		FIELD_PREP(BAT_CHARGE_DSEL_MASK, 0)
#define BAT_CHARGE_DSEL_OFF		FIELD_PREP(BAT_CHARGE_DSEL_MASK, 1)
#define BAT_CHARGE_EN_MASK_BIT		BIT(0 + 16)
#define BAT_CHARGE_EN			BIT(0)
#define RTC_TRIM_CTRL			0x60

struct sunplus_rtc {
	struct rtc_device *rtc;
	struct resource *res;
	struct clk *rtcclk;
	struct reset_control *rstc;
	void __iomem *reg_base;
	int irq;
};

static void sp_get_seconds(struct device *dev, unsigned long *secs)
{
	struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);

	*secs = (unsigned long)readl(sp_rtc->reg_base + RTC_TIMER_OUT);
}

static void sp_set_seconds(struct device *dev, unsigned long secs)
{
	struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);

	writel((u32)secs, sp_rtc->reg_base + RTC_TIMER_SET);
}

static int sp_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	unsigned long secs;

	sp_get_seconds(dev, &secs);
	rtc_time64_to_tm(secs, tm);

	return 0;
}

static int sp_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	unsigned long secs;

	secs = rtc_tm_to_time64(tm);
	dev_dbg(dev, "%s, secs = %lu\n", __func__, secs);
	sp_set_seconds(dev, secs);

	return 0;
}

static int sp_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);
	unsigned long alarm_time;

	alarm_time = rtc_tm_to_time64(&alrm->time);
	dev_dbg(dev, "%s, alarm_time: %u\n", __func__, (u32)(alarm_time));
	writel((u32)alarm_time, sp_rtc->reg_base + RTC_ALARM_SET);

	return 0;
}

static int sp_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);
	unsigned int alarm_time;

	alarm_time = readl(sp_rtc->reg_base + RTC_ALARM_SET);
	dev_dbg(dev, "%s, alarm_time: %u\n", __func__, alarm_time);

	if (alarm_time == 0)
		alrm->enabled = 0;
	else
		alrm->enabled = 1;

	rtc_time64_to_tm((unsigned long)(alarm_time), &alrm->time);

	return 0;
}

static int sp_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
	struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);

	if (enabled)
		writel((TIMER_FREEZE_MASK_BIT | DIS_SYS_RST_RTC_MASK_BIT |
			RTC32K_MODE_RESET_MASK_BIT | ALARM_EN_OVERDUE_MASK_BIT |
			ALARM_EN_PMC_MASK_BIT | ALARM_EN_MASK_BIT) |
			(DIS_SYS_RST_RTC | ALARM_EN_OVERDUE | ALARM_EN_PMC | ALARM_EN),
			sp_rtc->reg_base + RTC_CTRL);
	else
		writel((ALARM_EN_OVERDUE_MASK_BIT | ALARM_EN_PMC_MASK_BIT | ALARM_EN_MASK_BIT) |
			0x0, sp_rtc->reg_base + RTC_CTRL);

	return 0;
}

static const struct rtc_class_ops sp_rtc_ops = {
	.read_time =		sp_rtc_read_time,
	.set_time =		sp_rtc_set_time,
	.set_alarm =		sp_rtc_set_alarm,
	.read_alarm =		sp_rtc_read_alarm,
	.alarm_irq_enable =	sp_rtc_alarm_irq_enable,
};

static irqreturn_t sp_rtc_irq_handler(int irq, void *dev_id)
{
	struct platform_device *plat_dev = dev_id;
	struct sunplus_rtc *sp_rtc = dev_get_drvdata(&plat_dev->dev);

	rtc_update_irq(sp_rtc->rtc, 1, RTC_IRQF | RTC_AF);
	dev_dbg(&plat_dev->dev, "[RTC] ALARM INT\n");

	return IRQ_HANDLED;
}

/*
 * -------------------------------------------------------------------------------------
 * bat_charge_rsel   bat_charge_dsel   bat_charge_en     Remarks
 *         x              x                 0            Disable
 *         0              0                 1            0.86mA (2K Ohm with diode)
 *         1              0                 1            1.81mA (250 Ohm with diode)
 *         2              0                 1            2.07mA (50 Ohm with diode)
 *         3              0                 1            16.0mA (0 Ohm with diode)
 *         0              1                 1            1.36mA (2K Ohm without diode)
 *         1              1                 1            3.99mA (250 Ohm without diode)
 *         2              1                 1            4.41mA (50 Ohm without diode)
 *         3              1                 1            16.0mA (0 Ohm without diode)
 * -------------------------------------------------------------------------------------
 */
static void sp_rtc_set_trickle_charger(struct device dev)
{
	struct sunplus_rtc *sp_rtc = dev_get_drvdata(&dev);
	u32 ohms, rsel;
	u32 chargeable;

	if (of_property_read_u32(dev.of_node, "trickle-resistor-ohms", &ohms) ||
	    of_property_read_u32(dev.of_node, "aux-voltage-chargeable", &chargeable)) {
		dev_warn(&dev, "battery charger disabled\n");
		return;
	}

	switch (ohms) {
	case 2000:
		rsel = BAT_CHARGE_RSEL_2K_OHM;
		break;
	case 250:
		rsel = BAT_CHARGE_RSEL_250_OHM;
		break;
	case 50:
		rsel = BAT_CHARGE_RSEL_50_OHM;
		break;
	case 0:
		rsel = BAT_CHARGE_RSEL_0_OHM;
		break;
	default:
		dev_err(&dev, "invalid charger resistor value (%d)\n", ohms);
		return;
	}

	writel(BAT_CHARGE_RSEL_MASK_BIT | rsel, sp_rtc->reg_base + RTC_BATT_CHARGE_CTRL);

	switch (chargeable) {
	case 0:
		writel(BAT_CHARGE_DSEL_MASK_BIT | BAT_CHARGE_DSEL_OFF,
		       sp_rtc->reg_base + RTC_BATT_CHARGE_CTRL);
		break;
	case 1:
		writel(BAT_CHARGE_DSEL_MASK_BIT | BAT_CHARGE_DSEL_ON,
		       sp_rtc->reg_base + RTC_BATT_CHARGE_CTRL);
		break;
	default:
		dev_err(&dev, "invalid aux-voltage-chargeable value (%d)\n", chargeable);
		return;
	}

	writel(BAT_CHARGE_EN_MASK_BIT | BAT_CHARGE_EN, sp_rtc->reg_base + RTC_BATT_CHARGE_CTRL);
}

static int sp_rtc_probe(struct platform_device *plat_dev)
{
	struct sunplus_rtc *sp_rtc;
	int ret;

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

	sp_rtc->res = platform_get_resource_byname(plat_dev, IORESOURCE_MEM, RTC_REG_NAME);
	sp_rtc->reg_base = devm_ioremap_resource(&plat_dev->dev, sp_rtc->res);
	if (IS_ERR(sp_rtc->reg_base))
		return dev_err_probe(&plat_dev->dev, PTR_ERR(sp_rtc->reg_base),
					    "%s devm_ioremap_resource fail\n", RTC_REG_NAME);
	dev_dbg(&plat_dev->dev, "res = 0x%x, reg_base = 0x%lx\n",
		sp_rtc->res->start, (unsigned long)sp_rtc->reg_base);

	sp_rtc->irq = platform_get_irq(plat_dev, 0);
	if (sp_rtc->irq < 0)
		return dev_err_probe(&plat_dev->dev, sp_rtc->irq, "platform_get_irq failed\n");

	ret = devm_request_irq(&plat_dev->dev, sp_rtc->irq, sp_rtc_irq_handler,
			       IRQF_TRIGGER_RISING, "rtc irq", plat_dev);
	if (ret)
		return dev_err_probe(&plat_dev->dev, ret, "devm_request_irq failed:\n");

	sp_rtc->rtcclk = devm_clk_get(&plat_dev->dev, NULL);
	if (IS_ERR(sp_rtc->rtcclk))
		return dev_err_probe(&plat_dev->dev, PTR_ERR(sp_rtc->rtcclk),
					    "devm_clk_get fail\n");

	sp_rtc->rstc = devm_reset_control_get_exclusive(&plat_dev->dev, NULL);
	if (IS_ERR(sp_rtc->rstc))
		return dev_err_probe(&plat_dev->dev, PTR_ERR(sp_rtc->rstc),
					    "failed to retrieve reset controller\n");

	ret = clk_prepare_enable(sp_rtc->rtcclk);
	if (ret)
		goto free_clk;

	ret = reset_control_deassert(sp_rtc->rstc);
	if (ret)
		goto free_reset_assert;

	device_init_wakeup(&plat_dev->dev, 1);
	dev_set_drvdata(&plat_dev->dev, sp_rtc);

	sp_rtc->rtc = devm_rtc_allocate_device(&plat_dev->dev);
	if (IS_ERR(sp_rtc->rtc)) {
		ret = PTR_ERR(sp_rtc->rtc);
		goto free_reset_assert;
	}

	sp_rtc->rtc->range_max = U32_MAX;
	sp_rtc->rtc->range_min = 0;
	sp_rtc->rtc->ops = &sp_rtc_ops;

	ret = devm_rtc_register_device(sp_rtc->rtc);
	if (ret)
		goto free_reset_assert;

	/* Setup trickle charger */
	if (plat_dev->dev.of_node)
		sp_rtc_set_trickle_charger(plat_dev->dev);

	/* Keep RTC from system reset */
	writel(DIS_SYS_RST_RTC_MASK_BIT | DIS_SYS_RST_RTC, sp_rtc->reg_base + RTC_CTRL);

	return 0;

free_reset_assert:
	reset_control_assert(sp_rtc->rstc);
free_clk:
	clk_disable_unprepare(sp_rtc->rtcclk);

	return ret;
}

static int sp_rtc_remove(struct platform_device *plat_dev)
{
	struct sunplus_rtc *sp_rtc = dev_get_drvdata(&plat_dev->dev);

	device_init_wakeup(&plat_dev->dev, 0);
	reset_control_assert(sp_rtc->rstc);
	clk_disable_unprepare(sp_rtc->rtcclk);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int sp_rtc_suspend(struct device *dev)
{
	struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
		enable_irq_wake(sp_rtc->irq);

	return 0;
}

static int sp_rtc_resume(struct device *dev)
{
	struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
		disable_irq_wake(sp_rtc->irq);

	return 0;
}
#endif

static const struct of_device_id sp_rtc_of_match[] = {
	{ .compatible = "sunplus,sp7021-rtc" },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, sp_rtc_of_match);

static SIMPLE_DEV_PM_OPS(sp_rtc_pm_ops, sp_rtc_suspend, sp_rtc_resume);

static struct platform_driver sp_rtc_driver = {
	.probe   = sp_rtc_probe,
	.remove  = sp_rtc_remove,
	.driver  = {
		.name	= "sp7021-rtc",
		.of_match_table = sp_rtc_of_match,
		.pm	= &sp_rtc_pm_ops,
	},
};
module_platform_driver(sp_rtc_driver);

MODULE_AUTHOR("Vincent Shih <vincent.sunplus@gmail.com>");
MODULE_DESCRIPTION("Sunplus RTC driver");
MODULE_LICENSE("GPL v2");