summaryrefslogtreecommitdiffstats
path: root/drivers/power/reset/at91-sama5d2_shdwc.c
blob: d8ecffe72f165cb9f0c4b04ab559a3475ae42491 (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
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
/*
 * Atmel SAMA5D2-Compatible Shutdown Controller (SHDWC) driver.
 * Found on some SoCs as the sama5d2 (obviously).
 *
 * Copyright (C) 2015 Atmel Corporation,
 *                    Nicolas Ferre <nicolas.ferre@atmel.com>
 *
 * Evolved from driver at91-poweroff.c.
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2.  This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 *
 * TODO:
 * - addition to status of other wake-up inputs [1 - 15]
 * - Analog Comparator wake-up alarm
 * - Serial RX wake-up alarm
 * - low power debouncer
 */

#include <linux/clk.h>
#include <linux/clk/at91_pmc.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/printk.h>

#include <soc/at91/at91sam9_ddrsdr.h>

#define SLOW_CLOCK_FREQ	32768

#define AT91_SHDW_CR	0x00		/* Shut Down Control Register */
#define AT91_SHDW_SHDW		BIT(0)			/* Shut Down command */
#define AT91_SHDW_KEY		(0xa5UL << 24)		/* KEY Password */

#define AT91_SHDW_MR	0x04		/* Shut Down Mode Register */
#define AT91_SHDW_WKUPDBC_SHIFT	24
#define AT91_SHDW_WKUPDBC_MASK	GENMASK(26, 24)
#define AT91_SHDW_WKUPDBC(x)	(((x) << AT91_SHDW_WKUPDBC_SHIFT) \
						& AT91_SHDW_WKUPDBC_MASK)

#define AT91_SHDW_SR	0x08		/* Shut Down Status Register */
#define AT91_SHDW_WKUPIS_SHIFT	16
#define AT91_SHDW_WKUPIS_MASK	GENMASK(31, 16)
#define AT91_SHDW_WKUPIS(x)	((1 << (x)) << AT91_SHDW_WKUPIS_SHIFT \
						& AT91_SHDW_WKUPIS_MASK)

#define AT91_SHDW_WUIR	0x0c		/* Shutdown Wake-up Inputs Register */
#define AT91_SHDW_WKUPEN_MASK	GENMASK(15, 0)
#define AT91_SHDW_WKUPEN(x)	((1 << (x)) & AT91_SHDW_WKUPEN_MASK)
#define AT91_SHDW_WKUPT_SHIFT	16
#define AT91_SHDW_WKUPT_MASK	GENMASK(31, 16)
#define AT91_SHDW_WKUPT(x)	((1 << (x)) << AT91_SHDW_WKUPT_SHIFT \
						& AT91_SHDW_WKUPT_MASK)

#define SHDW_WK_PIN(reg, cfg)	((reg) & AT91_SHDW_WKUPIS((cfg)->wkup_pin_input))
#define SHDW_RTCWK(reg, cfg)	(((reg) >> ((cfg)->sr_rtcwk_shift)) & 0x1)
#define SHDW_RTTWK(reg, cfg)	(((reg) >> ((cfg)->sr_rttwk_shift)) & 0x1)
#define SHDW_RTCWKEN(cfg)	(1 << ((cfg)->mr_rtcwk_shift))
#define SHDW_RTTWKEN(cfg)	(1 << ((cfg)->mr_rttwk_shift))

#define DBC_PERIOD_US(x)	DIV_ROUND_UP_ULL((1000000 * (x)), \
							SLOW_CLOCK_FREQ)

#define SHDW_CFG_NOT_USED	(32)

struct shdwc_reg_config {
	u8 wkup_pin_input;
	u8 mr_rtcwk_shift;
	u8 mr_rttwk_shift;
	u8 sr_rtcwk_shift;
	u8 sr_rttwk_shift;
};

struct pmc_reg_config {
	u8 mckr;
};

struct ddrc_reg_config {
	u32 type_offset;
	u32 type_mask;
};

struct reg_config {
	struct shdwc_reg_config shdwc;
	struct pmc_reg_config pmc;
	struct ddrc_reg_config ddrc;
};

struct shdwc {
	const struct reg_config *rcfg;
	struct clk *sclk;
	void __iomem *shdwc_base;
	void __iomem *mpddrc_base;
	void __iomem *pmc_base;
};

/*
 * Hold configuration here, cannot be more than one instance of the driver
 * since pm_power_off itself is global.
 */
static struct shdwc *at91_shdwc;

static const unsigned long long sdwc_dbc_period[] = {
	0, 3, 32, 512, 4096, 32768,
};

static void __init at91_wakeup_status(struct platform_device *pdev)
{
	struct shdwc *shdw = platform_get_drvdata(pdev);
	const struct reg_config *rcfg = shdw->rcfg;
	u32 reg;
	char *reason = "unknown";

	reg = readl(shdw->shdwc_base + AT91_SHDW_SR);

	dev_dbg(&pdev->dev, "%s: status = %#x\n", __func__, reg);

	/* Simple power-on, just bail out */
	if (!reg)
		return;

	if (SHDW_WK_PIN(reg, &rcfg->shdwc))
		reason = "WKUP pin";
	else if (SHDW_RTCWK(reg, &rcfg->shdwc))
		reason = "RTC";
	else if (SHDW_RTTWK(reg, &rcfg->shdwc))
		reason = "RTT";

	pr_info("AT91: Wake-Up source: %s\n", reason);
}

static void at91_poweroff(void)
{
	asm volatile(
		/* Align to cache lines */
		".balign 32\n\t"

		/* Ensure AT91_SHDW_CR is in the TLB by reading it */
		"	ldr	r6, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t"

		/* Power down SDRAM0 */
		"	tst	%0, #0\n\t"
		"	beq	1f\n\t"
		"	str	%1, [%0, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t"

		/* Switch the master clock source to slow clock. */
		"1:	ldr	r6, [%4, %5]\n\t"
		"	bic	r6, r6,  #" __stringify(AT91_PMC_CSS) "\n\t"
		"	str	r6, [%4, %5]\n\t"
		/* Wait for clock switch. */
		"2:	ldr	r6, [%4, #" __stringify(AT91_PMC_SR) "]\n\t"
		"	tst	r6, #"	    __stringify(AT91_PMC_MCKRDY) "\n\t"
		"	beq	2b\n\t"

		/* Shutdown CPU */
		"	str	%3, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t"

		"	b	.\n\t"
		:
		: "r" (at91_shdwc->mpddrc_base),
		  "r" cpu_to_le32(AT91_DDRSDRC_LPDDR2_PWOFF),
		  "r" (at91_shdwc->shdwc_base),
		  "r" cpu_to_le32(AT91_SHDW_KEY | AT91_SHDW_SHDW),
		  "r" (at91_shdwc->pmc_base),
		  "r" (at91_shdwc->rcfg->pmc.mckr)
		: "r6");
}

static u32 at91_shdwc_debouncer_value(struct platform_device *pdev,
				      u32 in_period_us)
{
	int i;
	int max_idx = ARRAY_SIZE(sdwc_dbc_period) - 1;
	unsigned long long period_us;
	unsigned long long max_period_us = DBC_PERIOD_US(sdwc_dbc_period[max_idx]);

	if (in_period_us > max_period_us) {
		dev_warn(&pdev->dev,
			 "debouncer period %u too big, reduced to %llu us\n",
			 in_period_us, max_period_us);
		return max_idx;
	}

	for (i = max_idx - 1; i > 0; i--) {
		period_us = DBC_PERIOD_US(sdwc_dbc_period[i]);
		dev_dbg(&pdev->dev, "%s: ref[%d] = %llu\n",
						__func__, i, period_us);
		if (in_period_us > period_us)
			break;
	}

	return i + 1;
}

static u32 at91_shdwc_get_wakeup_input(struct platform_device *pdev,
				       struct device_node *np)
{
	struct device_node *cnp;
	u32 wk_input_mask;
	u32 wuir = 0;
	u32 wk_input;

	for_each_child_of_node(np, cnp) {
		if (of_property_read_u32(cnp, "reg", &wk_input)) {
			dev_warn(&pdev->dev, "reg property is missing for %pOF\n",
				 cnp);
			continue;
		}

		wk_input_mask = 1 << wk_input;
		if (!(wk_input_mask & AT91_SHDW_WKUPEN_MASK)) {
			dev_warn(&pdev->dev,
				 "wake-up input %d out of bounds ignore\n",
				 wk_input);
			continue;
		}
		wuir |= wk_input_mask;

		if (of_property_read_bool(cnp, "atmel,wakeup-active-high"))
			wuir |= AT91_SHDW_WKUPT(wk_input);

		dev_dbg(&pdev->dev, "%s: (child %d) wuir = %#x\n",
						__func__, wk_input, wuir);
	}

	return wuir;
}

static void at91_shdwc_dt_configure(struct platform_device *pdev)
{
	struct shdwc *shdw = platform_get_drvdata(pdev);
	const struct reg_config *rcfg = shdw->rcfg;
	struct device_node *np = pdev->dev.of_node;
	u32 mode = 0, tmp, input;

	if (!np) {
		dev_err(&pdev->dev, "device node not found\n");
		return;
	}

	if (!of_property_read_u32(np, "debounce-delay-us", &tmp))
		mode |= AT91_SHDW_WKUPDBC(at91_shdwc_debouncer_value(pdev, tmp));

	if (of_property_read_bool(np, "atmel,wakeup-rtc-timer"))
		mode |= SHDW_RTCWKEN(&rcfg->shdwc);

	if (of_property_read_bool(np, "atmel,wakeup-rtt-timer"))
		mode |= SHDW_RTTWKEN(&rcfg->shdwc);

	dev_dbg(&pdev->dev, "%s: mode = %#x\n", __func__, mode);
	writel(mode, shdw->shdwc_base + AT91_SHDW_MR);

	input = at91_shdwc_get_wakeup_input(pdev, np);
	writel(input, shdw->shdwc_base + AT91_SHDW_WUIR);
}

static const struct reg_config sama5d2_reg_config = {
	.shdwc = {
		.wkup_pin_input = 0,
		.mr_rtcwk_shift = 17,
		.mr_rttwk_shift	= SHDW_CFG_NOT_USED,
		.sr_rtcwk_shift = 5,
		.sr_rttwk_shift = SHDW_CFG_NOT_USED,
	},
	.pmc = {
		.mckr		= 0x30,
	},
	.ddrc = {
		.type_offset	= AT91_DDRSDRC_MDR,
		.type_mask	= AT91_DDRSDRC_MD
	},
};

static const struct reg_config sam9x60_reg_config = {
	.shdwc = {
		.wkup_pin_input = 0,
		.mr_rtcwk_shift = 17,
		.mr_rttwk_shift = 16,
		.sr_rtcwk_shift = 5,
		.sr_rttwk_shift = 4,
	},
	.pmc = {
		.mckr		= 0x28,
	},
	.ddrc = {
		.type_offset	= AT91_DDRSDRC_MDR,
		.type_mask	= AT91_DDRSDRC_MD
	},
};

static const struct reg_config sama7g5_reg_config = {
	.shdwc = {
		.wkup_pin_input = 0,
		.mr_rtcwk_shift = 17,
		.mr_rttwk_shift = 16,
		.sr_rtcwk_shift = 5,
		.sr_rttwk_shift = 4,
	},
	.pmc = {
		.mckr		= 0x28,
	},
};

static const struct of_device_id at91_shdwc_of_match[] = {
	{
		.compatible = "atmel,sama5d2-shdwc",
		.data = &sama5d2_reg_config,
	},
	{
		.compatible = "microchip,sam9x60-shdwc",
		.data = &sam9x60_reg_config,
	},
	{
		.compatible = "microchip,sama7g5-shdwc",
		.data = &sama7g5_reg_config,
	}, {
		/*sentinel*/
	}
};
MODULE_DEVICE_TABLE(of, at91_shdwc_of_match);

static const struct of_device_id at91_pmc_ids[] = {
	{ .compatible = "atmel,sama5d2-pmc" },
	{ .compatible = "microchip,sam9x60-pmc" },
	{ .compatible = "microchip,sama7g5-pmc" },
	{ /* Sentinel. */ }
};

static int __init at91_shdwc_probe(struct platform_device *pdev)
{
	struct resource *res;
	const struct of_device_id *match;
	struct device_node *np;
	u32 ddr_type;
	int ret;

	if (!pdev->dev.of_node)
		return -ENODEV;

	if (at91_shdwc)
		return -EBUSY;

	at91_shdwc = devm_kzalloc(&pdev->dev, sizeof(*at91_shdwc), GFP_KERNEL);
	if (!at91_shdwc)
		return -ENOMEM;

	platform_set_drvdata(pdev, at91_shdwc);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	at91_shdwc->shdwc_base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(at91_shdwc->shdwc_base))
		return PTR_ERR(at91_shdwc->shdwc_base);

	match = of_match_node(at91_shdwc_of_match, pdev->dev.of_node);
	at91_shdwc->rcfg = match->data;

	at91_shdwc->sclk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(at91_shdwc->sclk))
		return PTR_ERR(at91_shdwc->sclk);

	ret = clk_prepare_enable(at91_shdwc->sclk);
	if (ret) {
		dev_err(&pdev->dev, "Could not enable slow clock\n");
		return ret;
	}

	at91_wakeup_status(pdev);

	at91_shdwc_dt_configure(pdev);

	np = of_find_matching_node(NULL, at91_pmc_ids);
	if (!np) {
		ret = -ENODEV;
		goto clk_disable;
	}

	at91_shdwc->pmc_base = of_iomap(np, 0);
	of_node_put(np);

	if (!at91_shdwc->pmc_base) {
		ret = -ENOMEM;
		goto clk_disable;
	}

	if (at91_shdwc->rcfg->ddrc.type_mask) {
		np = of_find_compatible_node(NULL, NULL,
					     "atmel,sama5d3-ddramc");
		if (!np) {
			ret = -ENODEV;
			goto unmap;
		}

		at91_shdwc->mpddrc_base = of_iomap(np, 0);
		of_node_put(np);

		if (!at91_shdwc->mpddrc_base) {
			ret = -ENOMEM;
			goto unmap;
		}

		ddr_type = readl(at91_shdwc->mpddrc_base +
				 at91_shdwc->rcfg->ddrc.type_offset) &
				 at91_shdwc->rcfg->ddrc.type_mask;
		if (ddr_type != AT91_DDRSDRC_MD_LPDDR2 &&
		    ddr_type != AT91_DDRSDRC_MD_LPDDR3) {
			iounmap(at91_shdwc->mpddrc_base);
			at91_shdwc->mpddrc_base = NULL;
		}
	}

	pm_power_off = at91_poweroff;

	return 0;

unmap:
	iounmap(at91_shdwc->pmc_base);
clk_disable:
	clk_disable_unprepare(at91_shdwc->sclk);

	return ret;
}

static int __exit at91_shdwc_remove(struct platform_device *pdev)
{
	struct shdwc *shdw = platform_get_drvdata(pdev);

	if (pm_power_off == at91_poweroff)
		pm_power_off = NULL;

	/* Reset values to disable wake-up features  */
	writel(0, shdw->shdwc_base + AT91_SHDW_MR);
	writel(0, shdw->shdwc_base + AT91_SHDW_WUIR);

	if (shdw->mpddrc_base)
		iounmap(shdw->mpddrc_base);
	iounmap(shdw->pmc_base);

	clk_disable_unprepare(shdw->sclk);

	return 0;
}

static struct platform_driver at91_shdwc_driver = {
	.remove = __exit_p(at91_shdwc_remove),
	.driver = {
		.name = "at91-shdwc",
		.of_match_table = at91_shdwc_of_match,
	},
};
module_platform_driver_probe(at91_shdwc_driver, at91_shdwc_probe);

MODULE_AUTHOR("Nicolas Ferre <nicolas.ferre@atmel.com>");
MODULE_DESCRIPTION("Atmel shutdown controller driver");
MODULE_LICENSE("GPL v2");