1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * An RTC driver for Allwinner A31/A23
4 *
5 * Copyright (c) 2014, Chen-Yu Tsai <wens@csie.org>
6 *
7 * based on rtc-sunxi.c
8 *
9 * An RTC driver for Allwinner A10/A20
10 *
11 * Copyright (c) 2013, Carlo Caione <carlo.caione@gmail.com>
12 */
13
14 #include <linux/clk.h>
15 #include <linux/clk-provider.h>
16 #include <linux/clk/sunxi-ng.h>
17 #include <linux/delay.h>
18 #include <linux/err.h>
19 #include <linux/fs.h>
20 #include <linux/init.h>
21 #include <linux/interrupt.h>
22 #include <linux/io.h>
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/of.h>
26 #include <linux/of_address.h>
27 #include <linux/platform_device.h>
28 #include <linux/rtc.h>
29 #include <linux/slab.h>
30 #include <linux/types.h>
31
32 /* Control register */
33 #define SUN6I_LOSC_CTRL 0x0000
34 #define SUN6I_LOSC_CTRL_KEY (0x16aa << 16)
35 #define SUN6I_LOSC_CTRL_AUTO_SWT_BYPASS BIT(15)
36 #define SUN6I_LOSC_CTRL_ALM_DHMS_ACC BIT(9)
37 #define SUN6I_LOSC_CTRL_RTC_HMS_ACC BIT(8)
38 #define SUN6I_LOSC_CTRL_RTC_YMD_ACC BIT(7)
39 #define SUN6I_LOSC_CTRL_EXT_LOSC_EN BIT(4)
40 #define SUN6I_LOSC_CTRL_EXT_OSC BIT(0)
41 #define SUN6I_LOSC_CTRL_ACC_MASK GENMASK(9, 7)
42
43 #define SUN6I_LOSC_CLK_PRESCAL 0x0008
44
45 /* RTC */
46 #define SUN6I_RTC_YMD 0x0010
47 #define SUN6I_RTC_HMS 0x0014
48
49 /* Alarm 0 (counter) */
50 #define SUN6I_ALRM_COUNTER 0x0020
51 /* This holds the remaining alarm seconds on older SoCs (current value) */
52 #define SUN6I_ALRM_COUNTER_HMS 0x0024
53 #define SUN6I_ALRM_EN 0x0028
54 #define SUN6I_ALRM_EN_CNT_EN BIT(0)
55 #define SUN6I_ALRM_IRQ_EN 0x002c
56 #define SUN6I_ALRM_IRQ_EN_CNT_IRQ_EN BIT(0)
57 #define SUN6I_ALRM_IRQ_STA 0x0030
58 #define SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND BIT(0)
59
60 /* Alarm 1 (wall clock) */
61 #define SUN6I_ALRM1_EN 0x0044
62 #define SUN6I_ALRM1_IRQ_EN 0x0048
63 #define SUN6I_ALRM1_IRQ_STA 0x004c
64 #define SUN6I_ALRM1_IRQ_STA_WEEK_IRQ_PEND BIT(0)
65
66 /* Alarm config */
67 #define SUN6I_ALARM_CONFIG 0x0050
68 #define SUN6I_ALARM_CONFIG_WAKEUP BIT(0)
69
70 #define SUN6I_LOSC_OUT_GATING 0x0060
71 #define SUN6I_LOSC_OUT_GATING_EN_OFFSET 0
72
73 /* General-purpose data */
74 #define SUN6I_GP_DATA 0x0100
75 #define SUN6I_GP_DATA_SIZE 0x20
76
77 /*
78 * Get date values
79 */
80 #define SUN6I_DATE_GET_DAY_VALUE(x) ((x) & 0x0000001f)
81 #define SUN6I_DATE_GET_MON_VALUE(x) (((x) & 0x00000f00) >> 8)
82 #define SUN6I_DATE_GET_YEAR_VALUE(x) (((x) & 0x003f0000) >> 16)
83 #define SUN6I_LEAP_GET_VALUE(x) (((x) & 0x00400000) >> 22)
84
85 /*
86 * Get time values
87 */
88 #define SUN6I_TIME_GET_SEC_VALUE(x) ((x) & 0x0000003f)
89 #define SUN6I_TIME_GET_MIN_VALUE(x) (((x) & 0x00003f00) >> 8)
90 #define SUN6I_TIME_GET_HOUR_VALUE(x) (((x) & 0x001f0000) >> 16)
91
92 /*
93 * Set date values
94 */
95 #define SUN6I_DATE_SET_DAY_VALUE(x) ((x) & 0x0000001f)
96 #define SUN6I_DATE_SET_MON_VALUE(x) ((x) << 8 & 0x00000f00)
97 #define SUN6I_DATE_SET_YEAR_VALUE(x) ((x) << 16 & 0x003f0000)
98 #define SUN6I_LEAP_SET_VALUE(x) ((x) << 22 & 0x00400000)
99
100 /*
101 * Set time values
102 */
103 #define SUN6I_TIME_SET_SEC_VALUE(x) ((x) & 0x0000003f)
104 #define SUN6I_TIME_SET_MIN_VALUE(x) ((x) << 8 & 0x00003f00)
105 #define SUN6I_TIME_SET_HOUR_VALUE(x) ((x) << 16 & 0x001f0000)
106
107 /*
108 * The year parameter passed to the driver is usually an offset relative to
109 * the year 1900. This macro is used to convert this offset to another one
110 * relative to the minimum year allowed by the hardware.
111 *
112 * The year range is 1970 - 2033. This range is selected to match Allwinner's
113 * driver, even though it is somewhat limited.
114 */
115 #define SUN6I_YEAR_MIN 1970
116 #define SUN6I_YEAR_OFF (SUN6I_YEAR_MIN - 1900)
117
118 #define SECS_PER_DAY (24 * 3600ULL)
119
120 /*
121 * There are other differences between models, including:
122 *
123 * - number of GPIO pins that can be configured to hold a certain level
124 * - crypto-key related registers (H5, H6)
125 * - boot process related (super standby, secondary processor entry address)
126 * registers (R40, H6)
127 * - SYS power domain controls (R40)
128 * - DCXO controls (H6)
129 * - RC oscillator calibration (H6)
130 *
131 * These functions are not covered by this driver.
132 */
133 struct sun6i_rtc_clk_data {
134 unsigned long rc_osc_rate;
135 unsigned int fixed_prescaler : 16;
136 unsigned int has_prescaler : 1;
137 unsigned int has_out_clk : 1;
138 unsigned int has_losc_en : 1;
139 unsigned int has_auto_swt : 1;
140 };
141
142 #define RTC_LINEAR_DAY BIT(0)
143
144 struct sun6i_rtc_dev {
145 struct rtc_device *rtc;
146 const struct sun6i_rtc_clk_data *data;
147 void __iomem *base;
148 int irq;
149 time64_t alarm;
150 unsigned long flags;
151
152 struct clk_hw hw;
153 struct clk_hw *int_osc;
154 struct clk *losc;
155 struct clk *ext_losc;
156
157 spinlock_t lock;
158 };
159
160 static struct sun6i_rtc_dev *sun6i_rtc;
161
sun6i_rtc_osc_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)162 static unsigned long sun6i_rtc_osc_recalc_rate(struct clk_hw *hw,
163 unsigned long parent_rate)
164 {
165 struct sun6i_rtc_dev *rtc = container_of(hw, struct sun6i_rtc_dev, hw);
166 u32 val = 0;
167
168 val = readl(rtc->base + SUN6I_LOSC_CTRL);
169 if (val & SUN6I_LOSC_CTRL_EXT_OSC)
170 return parent_rate;
171
172 if (rtc->data->fixed_prescaler)
173 parent_rate /= rtc->data->fixed_prescaler;
174
175 if (rtc->data->has_prescaler) {
176 val = readl(rtc->base + SUN6I_LOSC_CLK_PRESCAL);
177 val &= GENMASK(4, 0);
178 }
179
180 return parent_rate / (val + 1);
181 }
182
sun6i_rtc_osc_get_parent(struct clk_hw * hw)183 static u8 sun6i_rtc_osc_get_parent(struct clk_hw *hw)
184 {
185 struct sun6i_rtc_dev *rtc = container_of(hw, struct sun6i_rtc_dev, hw);
186
187 return readl(rtc->base + SUN6I_LOSC_CTRL) & SUN6I_LOSC_CTRL_EXT_OSC;
188 }
189
sun6i_rtc_osc_set_parent(struct clk_hw * hw,u8 index)190 static int sun6i_rtc_osc_set_parent(struct clk_hw *hw, u8 index)
191 {
192 struct sun6i_rtc_dev *rtc = container_of(hw, struct sun6i_rtc_dev, hw);
193 unsigned long flags;
194 u32 val;
195
196 if (index > 1)
197 return -EINVAL;
198
199 spin_lock_irqsave(&rtc->lock, flags);
200 val = readl(rtc->base + SUN6I_LOSC_CTRL);
201 val &= ~SUN6I_LOSC_CTRL_EXT_OSC;
202 val |= SUN6I_LOSC_CTRL_KEY;
203 val |= index ? SUN6I_LOSC_CTRL_EXT_OSC : 0;
204 if (rtc->data->has_losc_en) {
205 val &= ~SUN6I_LOSC_CTRL_EXT_LOSC_EN;
206 val |= index ? SUN6I_LOSC_CTRL_EXT_LOSC_EN : 0;
207 }
208 writel(val, rtc->base + SUN6I_LOSC_CTRL);
209 spin_unlock_irqrestore(&rtc->lock, flags);
210
211 return 0;
212 }
213
214 static const struct clk_ops sun6i_rtc_osc_ops = {
215 .recalc_rate = sun6i_rtc_osc_recalc_rate,
216 .determine_rate = clk_hw_determine_rate_no_reparent,
217
218 .get_parent = sun6i_rtc_osc_get_parent,
219 .set_parent = sun6i_rtc_osc_set_parent,
220 };
221
sun6i_rtc_clk_init(struct device_node * node,const struct sun6i_rtc_clk_data * data)222 static void __init sun6i_rtc_clk_init(struct device_node *node,
223 const struct sun6i_rtc_clk_data *data)
224 {
225 struct clk_hw_onecell_data *clk_data;
226 struct sun6i_rtc_dev *rtc;
227 struct clk_init_data init = {
228 .ops = &sun6i_rtc_osc_ops,
229 .name = "losc",
230 };
231 const char *iosc_name = "rtc-int-osc";
232 const char *clkout_name = "osc32k-out";
233 const char *parents[2];
234 u32 reg;
235
236 rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
237 if (!rtc)
238 return;
239
240 rtc->data = data;
241 clk_data = kzalloc(struct_size(clk_data, hws, 3), GFP_KERNEL);
242 if (!clk_data) {
243 kfree(rtc);
244 return;
245 }
246
247 spin_lock_init(&rtc->lock);
248
249 rtc->base = of_io_request_and_map(node, 0, of_node_full_name(node));
250 if (IS_ERR(rtc->base)) {
251 pr_crit("Can't map RTC registers");
252 goto err;
253 }
254
255 reg = SUN6I_LOSC_CTRL_KEY;
256 if (rtc->data->has_auto_swt) {
257 /* Bypass auto-switch to int osc, on ext losc failure */
258 reg |= SUN6I_LOSC_CTRL_AUTO_SWT_BYPASS;
259 writel(reg, rtc->base + SUN6I_LOSC_CTRL);
260 }
261
262 /* Switch to the external, more precise, oscillator, if present */
263 if (of_property_present(node, "clocks")) {
264 reg |= SUN6I_LOSC_CTRL_EXT_OSC;
265 if (rtc->data->has_losc_en)
266 reg |= SUN6I_LOSC_CTRL_EXT_LOSC_EN;
267 }
268 writel(reg, rtc->base + SUN6I_LOSC_CTRL);
269
270 /* Yes, I know, this is ugly. */
271 sun6i_rtc = rtc;
272
273 of_property_read_string_index(node, "clock-output-names", 2,
274 &iosc_name);
275
276 rtc->int_osc = clk_hw_register_fixed_rate_with_accuracy(NULL,
277 iosc_name,
278 NULL, 0,
279 rtc->data->rc_osc_rate,
280 300000000);
281 if (IS_ERR(rtc->int_osc)) {
282 pr_crit("Couldn't register the internal oscillator\n");
283 goto err;
284 }
285
286 parents[0] = clk_hw_get_name(rtc->int_osc);
287 /* If there is no external oscillator, this will be NULL and ... */
288 parents[1] = of_clk_get_parent_name(node, 0);
289
290 rtc->hw.init = &init;
291
292 init.parent_names = parents;
293 /* ... number of clock parents will be 1. */
294 init.num_parents = of_clk_get_parent_count(node) + 1;
295 of_property_read_string_index(node, "clock-output-names", 0,
296 &init.name);
297
298 rtc->losc = clk_register(NULL, &rtc->hw);
299 if (IS_ERR(rtc->losc)) {
300 pr_crit("Couldn't register the LOSC clock\n");
301 goto err_register;
302 }
303
304 of_property_read_string_index(node, "clock-output-names", 1,
305 &clkout_name);
306 rtc->ext_losc = clk_register_gate(NULL, clkout_name, init.name,
307 0, rtc->base + SUN6I_LOSC_OUT_GATING,
308 SUN6I_LOSC_OUT_GATING_EN_OFFSET, 0,
309 &rtc->lock);
310 if (IS_ERR(rtc->ext_losc)) {
311 pr_crit("Couldn't register the LOSC external gate\n");
312 goto err_register;
313 }
314
315 clk_data->num = 3;
316 clk_data->hws[0] = &rtc->hw;
317 clk_data->hws[1] = __clk_get_hw(rtc->ext_losc);
318 clk_data->hws[2] = rtc->int_osc;
319 of_clk_add_hw_provider(node, of_clk_hw_onecell_get, clk_data);
320 return;
321
322 err_register:
323 clk_hw_unregister_fixed_rate(rtc->int_osc);
324 err:
325 kfree(clk_data);
326 }
327
328 static const struct sun6i_rtc_clk_data sun6i_a31_rtc_data = {
329 .rc_osc_rate = 667000, /* datasheet says 600 ~ 700 KHz */
330 .has_prescaler = 1,
331 };
332
sun6i_a31_rtc_clk_init(struct device_node * node)333 static void __init sun6i_a31_rtc_clk_init(struct device_node *node)
334 {
335 sun6i_rtc_clk_init(node, &sun6i_a31_rtc_data);
336 }
337 CLK_OF_DECLARE_DRIVER(sun6i_a31_rtc_clk, "allwinner,sun6i-a31-rtc",
338 sun6i_a31_rtc_clk_init);
339
340 static const struct sun6i_rtc_clk_data sun8i_a23_rtc_data = {
341 .rc_osc_rate = 667000, /* datasheet says 600 ~ 700 KHz */
342 .has_prescaler = 1,
343 .has_out_clk = 1,
344 };
345
sun8i_a23_rtc_clk_init(struct device_node * node)346 static void __init sun8i_a23_rtc_clk_init(struct device_node *node)
347 {
348 sun6i_rtc_clk_init(node, &sun8i_a23_rtc_data);
349 }
350 CLK_OF_DECLARE_DRIVER(sun8i_a23_rtc_clk, "allwinner,sun8i-a23-rtc",
351 sun8i_a23_rtc_clk_init);
352
353 static const struct sun6i_rtc_clk_data sun8i_h3_rtc_data = {
354 .rc_osc_rate = 16000000,
355 .fixed_prescaler = 32,
356 .has_prescaler = 1,
357 .has_out_clk = 1,
358 };
359
sun8i_h3_rtc_clk_init(struct device_node * node)360 static void __init sun8i_h3_rtc_clk_init(struct device_node *node)
361 {
362 sun6i_rtc_clk_init(node, &sun8i_h3_rtc_data);
363 }
364 CLK_OF_DECLARE_DRIVER(sun8i_h3_rtc_clk, "allwinner,sun8i-h3-rtc",
365 sun8i_h3_rtc_clk_init);
366 /* As far as we are concerned, clocks for H5 are the same as H3 */
367 CLK_OF_DECLARE_DRIVER(sun50i_h5_rtc_clk, "allwinner,sun50i-h5-rtc",
368 sun8i_h3_rtc_clk_init);
369
370 static const struct sun6i_rtc_clk_data sun50i_h6_rtc_data = {
371 .rc_osc_rate = 16000000,
372 .fixed_prescaler = 32,
373 .has_prescaler = 1,
374 .has_out_clk = 1,
375 .has_losc_en = 1,
376 .has_auto_swt = 1,
377 };
378
sun50i_h6_rtc_clk_init(struct device_node * node)379 static void __init sun50i_h6_rtc_clk_init(struct device_node *node)
380 {
381 sun6i_rtc_clk_init(node, &sun50i_h6_rtc_data);
382 }
383 CLK_OF_DECLARE_DRIVER(sun50i_h6_rtc_clk, "allwinner,sun50i-h6-rtc",
384 sun50i_h6_rtc_clk_init);
385
386 /*
387 * The R40 user manual is self-conflicting on whether the prescaler is
388 * fixed or configurable. The clock diagram shows it as fixed, but there
389 * is also a configurable divider in the RTC block.
390 */
391 static const struct sun6i_rtc_clk_data sun8i_r40_rtc_data = {
392 .rc_osc_rate = 16000000,
393 .fixed_prescaler = 512,
394 };
sun8i_r40_rtc_clk_init(struct device_node * node)395 static void __init sun8i_r40_rtc_clk_init(struct device_node *node)
396 {
397 sun6i_rtc_clk_init(node, &sun8i_r40_rtc_data);
398 }
399 CLK_OF_DECLARE_DRIVER(sun8i_r40_rtc_clk, "allwinner,sun8i-r40-rtc",
400 sun8i_r40_rtc_clk_init);
401
402 static const struct sun6i_rtc_clk_data sun8i_v3_rtc_data = {
403 .rc_osc_rate = 32000,
404 .has_out_clk = 1,
405 .has_auto_swt = 1,
406 };
407
sun8i_v3_rtc_clk_init(struct device_node * node)408 static void __init sun8i_v3_rtc_clk_init(struct device_node *node)
409 {
410 sun6i_rtc_clk_init(node, &sun8i_v3_rtc_data);
411 }
412 CLK_OF_DECLARE_DRIVER(sun8i_v3_rtc_clk, "allwinner,sun8i-v3-rtc",
413 sun8i_v3_rtc_clk_init);
414
sun6i_rtc_alarmirq(int irq,void * id)415 static irqreturn_t sun6i_rtc_alarmirq(int irq, void *id)
416 {
417 struct sun6i_rtc_dev *chip = (struct sun6i_rtc_dev *) id;
418 irqreturn_t ret = IRQ_NONE;
419 u32 val;
420
421 spin_lock(&chip->lock);
422 val = readl(chip->base + SUN6I_ALRM_IRQ_STA);
423
424 if (val & SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND) {
425 val |= SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND;
426 writel(val, chip->base + SUN6I_ALRM_IRQ_STA);
427
428 rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF);
429
430 ret = IRQ_HANDLED;
431 }
432 spin_unlock(&chip->lock);
433
434 return ret;
435 }
436
sun6i_rtc_setaie(int to,struct sun6i_rtc_dev * chip)437 static void sun6i_rtc_setaie(int to, struct sun6i_rtc_dev *chip)
438 {
439 u32 alrm_val = 0;
440 u32 alrm_irq_val = 0;
441 u32 alrm_wake_val = 0;
442 unsigned long flags;
443
444 if (to) {
445 alrm_val = SUN6I_ALRM_EN_CNT_EN;
446 alrm_irq_val = SUN6I_ALRM_IRQ_EN_CNT_IRQ_EN;
447 alrm_wake_val = SUN6I_ALARM_CONFIG_WAKEUP;
448 } else {
449 writel(SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND,
450 chip->base + SUN6I_ALRM_IRQ_STA);
451 }
452
453 spin_lock_irqsave(&chip->lock, flags);
454 writel(alrm_val, chip->base + SUN6I_ALRM_EN);
455 writel(alrm_irq_val, chip->base + SUN6I_ALRM_IRQ_EN);
456 writel(alrm_wake_val, chip->base + SUN6I_ALARM_CONFIG);
457 spin_unlock_irqrestore(&chip->lock, flags);
458 }
459
sun6i_rtc_gettime(struct device * dev,struct rtc_time * rtc_tm)460 static int sun6i_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
461 {
462 struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
463 u32 date, time;
464
465 /*
466 * read again in case it changes
467 */
468 do {
469 date = readl(chip->base + SUN6I_RTC_YMD);
470 time = readl(chip->base + SUN6I_RTC_HMS);
471 } while ((date != readl(chip->base + SUN6I_RTC_YMD)) ||
472 (time != readl(chip->base + SUN6I_RTC_HMS)));
473
474 if (chip->flags & RTC_LINEAR_DAY) {
475 /*
476 * Newer chips store a linear day number, the manual
477 * does not mandate any epoch base. The BSP driver uses
478 * the UNIX epoch, let's just copy that, as it's the
479 * easiest anyway.
480 */
481 rtc_time64_to_tm((date & 0xffff) * SECS_PER_DAY, rtc_tm);
482 } else {
483 rtc_tm->tm_mday = SUN6I_DATE_GET_DAY_VALUE(date);
484 rtc_tm->tm_mon = SUN6I_DATE_GET_MON_VALUE(date) - 1;
485 rtc_tm->tm_year = SUN6I_DATE_GET_YEAR_VALUE(date);
486
487 /*
488 * switch from (data_year->min)-relative offset to
489 * a (1900)-relative one
490 */
491 rtc_tm->tm_year += SUN6I_YEAR_OFF;
492 }
493
494 rtc_tm->tm_sec = SUN6I_TIME_GET_SEC_VALUE(time);
495 rtc_tm->tm_min = SUN6I_TIME_GET_MIN_VALUE(time);
496 rtc_tm->tm_hour = SUN6I_TIME_GET_HOUR_VALUE(time);
497
498 return 0;
499 }
500
sun6i_rtc_getalarm(struct device * dev,struct rtc_wkalrm * wkalrm)501 static int sun6i_rtc_getalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
502 {
503 struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
504 unsigned long flags;
505 u32 alrm_st;
506 u32 alrm_en;
507
508 spin_lock_irqsave(&chip->lock, flags);
509 alrm_en = readl(chip->base + SUN6I_ALRM_IRQ_EN);
510 alrm_st = readl(chip->base + SUN6I_ALRM_IRQ_STA);
511 spin_unlock_irqrestore(&chip->lock, flags);
512
513 wkalrm->enabled = !!(alrm_en & SUN6I_ALRM_EN_CNT_EN);
514 wkalrm->pending = !!(alrm_st & SUN6I_ALRM_EN_CNT_EN);
515 rtc_time64_to_tm(chip->alarm, &wkalrm->time);
516
517 return 0;
518 }
519
sun6i_rtc_setalarm(struct device * dev,struct rtc_wkalrm * wkalrm)520 static int sun6i_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
521 {
522 struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
523 struct rtc_time *alrm_tm = &wkalrm->time;
524 struct rtc_time tm_now;
525 time64_t time_set;
526 u32 counter_val, counter_val_hms;
527 int ret;
528
529 time_set = rtc_tm_to_time64(alrm_tm);
530
531 if (chip->flags & RTC_LINEAR_DAY) {
532 /*
533 * The alarm registers hold the actual alarm time, encoded
534 * in the same way (linear day + HMS) as the current time.
535 */
536 counter_val_hms = SUN6I_TIME_SET_SEC_VALUE(alrm_tm->tm_sec) |
537 SUN6I_TIME_SET_MIN_VALUE(alrm_tm->tm_min) |
538 SUN6I_TIME_SET_HOUR_VALUE(alrm_tm->tm_hour);
539 /* The division will cut off the H:M:S part of alrm_tm. */
540 counter_val = div_u64(rtc_tm_to_time64(alrm_tm), SECS_PER_DAY);
541 } else {
542 /* The alarm register holds the number of seconds left. */
543 time64_t time_now;
544
545 ret = sun6i_rtc_gettime(dev, &tm_now);
546 if (ret < 0) {
547 dev_err(dev, "Error in getting time\n");
548 return -EINVAL;
549 }
550
551 time_now = rtc_tm_to_time64(&tm_now);
552 if (time_set <= time_now) {
553 dev_err(dev, "Date to set in the past\n");
554 return -EINVAL;
555 }
556 if ((time_set - time_now) > U32_MAX) {
557 dev_err(dev, "Date too far in the future\n");
558 return -EINVAL;
559 }
560
561 counter_val = time_set - time_now;
562 }
563
564 sun6i_rtc_setaie(0, chip);
565 writel(0, chip->base + SUN6I_ALRM_COUNTER);
566 if (chip->flags & RTC_LINEAR_DAY)
567 writel(0, chip->base + SUN6I_ALRM_COUNTER_HMS);
568 usleep_range(100, 300);
569
570 writel(counter_val, chip->base + SUN6I_ALRM_COUNTER);
571 if (chip->flags & RTC_LINEAR_DAY)
572 writel(counter_val_hms, chip->base + SUN6I_ALRM_COUNTER_HMS);
573 chip->alarm = time_set;
574
575 sun6i_rtc_setaie(wkalrm->enabled, chip);
576
577 return 0;
578 }
579
sun6i_rtc_wait(struct sun6i_rtc_dev * chip,int offset,unsigned int mask,unsigned int ms_timeout)580 static int sun6i_rtc_wait(struct sun6i_rtc_dev *chip, int offset,
581 unsigned int mask, unsigned int ms_timeout)
582 {
583 const unsigned long timeout = jiffies + msecs_to_jiffies(ms_timeout);
584 u32 reg;
585
586 do {
587 reg = readl(chip->base + offset);
588 reg &= mask;
589
590 if (!reg)
591 return 0;
592
593 } while (time_before(jiffies, timeout));
594
595 return -ETIMEDOUT;
596 }
597
sun6i_rtc_settime(struct device * dev,struct rtc_time * rtc_tm)598 static int sun6i_rtc_settime(struct device *dev, struct rtc_time *rtc_tm)
599 {
600 struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
601 u32 date = 0;
602 u32 time = 0;
603
604 time = SUN6I_TIME_SET_SEC_VALUE(rtc_tm->tm_sec) |
605 SUN6I_TIME_SET_MIN_VALUE(rtc_tm->tm_min) |
606 SUN6I_TIME_SET_HOUR_VALUE(rtc_tm->tm_hour);
607
608 if (chip->flags & RTC_LINEAR_DAY) {
609 /* The division will cut off the H:M:S part of rtc_tm. */
610 date = div_u64(rtc_tm_to_time64(rtc_tm), SECS_PER_DAY);
611 } else {
612 rtc_tm->tm_year -= SUN6I_YEAR_OFF;
613 rtc_tm->tm_mon += 1;
614
615 date = SUN6I_DATE_SET_DAY_VALUE(rtc_tm->tm_mday) |
616 SUN6I_DATE_SET_MON_VALUE(rtc_tm->tm_mon) |
617 SUN6I_DATE_SET_YEAR_VALUE(rtc_tm->tm_year);
618
619 if (is_leap_year(rtc_tm->tm_year + SUN6I_YEAR_MIN))
620 date |= SUN6I_LEAP_SET_VALUE(1);
621 }
622
623 /* Check whether registers are writable */
624 if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
625 SUN6I_LOSC_CTRL_ACC_MASK, 50)) {
626 dev_err(dev, "rtc is still busy.\n");
627 return -EBUSY;
628 }
629
630 writel(time, chip->base + SUN6I_RTC_HMS);
631
632 /*
633 * After writing the RTC HH-MM-SS register, the
634 * SUN6I_LOSC_CTRL_RTC_HMS_ACC bit is set and it will not
635 * be cleared until the real writing operation is finished
636 */
637
638 if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
639 SUN6I_LOSC_CTRL_RTC_HMS_ACC, 50)) {
640 dev_err(dev, "Failed to set rtc time.\n");
641 return -ETIMEDOUT;
642 }
643
644 writel(date, chip->base + SUN6I_RTC_YMD);
645
646 /*
647 * After writing the RTC YY-MM-DD register, the
648 * SUN6I_LOSC_CTRL_RTC_YMD_ACC bit is set and it will not
649 * be cleared until the real writing operation is finished
650 */
651
652 if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
653 SUN6I_LOSC_CTRL_RTC_YMD_ACC, 50)) {
654 dev_err(dev, "Failed to set rtc time.\n");
655 return -ETIMEDOUT;
656 }
657
658 return 0;
659 }
660
sun6i_rtc_alarm_irq_enable(struct device * dev,unsigned int enabled)661 static int sun6i_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
662 {
663 struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
664
665 if (!enabled)
666 sun6i_rtc_setaie(enabled, chip);
667
668 return 0;
669 }
670
671 static const struct rtc_class_ops sun6i_rtc_ops = {
672 .read_time = sun6i_rtc_gettime,
673 .set_time = sun6i_rtc_settime,
674 .read_alarm = sun6i_rtc_getalarm,
675 .set_alarm = sun6i_rtc_setalarm,
676 .alarm_irq_enable = sun6i_rtc_alarm_irq_enable
677 };
678
sun6i_rtc_nvmem_read(void * priv,unsigned int offset,void * _val,size_t bytes)679 static int sun6i_rtc_nvmem_read(void *priv, unsigned int offset, void *_val, size_t bytes)
680 {
681 struct sun6i_rtc_dev *chip = priv;
682 u32 *val = _val;
683 int i;
684
685 for (i = 0; i < bytes / 4; ++i)
686 val[i] = readl(chip->base + SUN6I_GP_DATA + offset + 4 * i);
687
688 return 0;
689 }
690
sun6i_rtc_nvmem_write(void * priv,unsigned int offset,void * _val,size_t bytes)691 static int sun6i_rtc_nvmem_write(void *priv, unsigned int offset, void *_val, size_t bytes)
692 {
693 struct sun6i_rtc_dev *chip = priv;
694 u32 *val = _val;
695 int i;
696
697 for (i = 0; i < bytes / 4; ++i)
698 writel(val[i], chip->base + SUN6I_GP_DATA + offset + 4 * i);
699
700 return 0;
701 }
702
703 static struct nvmem_config sun6i_rtc_nvmem_cfg = {
704 .type = NVMEM_TYPE_BATTERY_BACKED,
705 .reg_read = sun6i_rtc_nvmem_read,
706 .reg_write = sun6i_rtc_nvmem_write,
707 .size = SUN6I_GP_DATA_SIZE,
708 .word_size = 4,
709 .stride = 4,
710 };
711
712 #ifdef CONFIG_PM_SLEEP
713 /* Enable IRQ wake on suspend, to wake up from RTC. */
sun6i_rtc_suspend(struct device * dev)714 static int sun6i_rtc_suspend(struct device *dev)
715 {
716 struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
717
718 if (device_may_wakeup(dev))
719 enable_irq_wake(chip->irq);
720
721 return 0;
722 }
723
724 /* Disable IRQ wake on resume. */
sun6i_rtc_resume(struct device * dev)725 static int sun6i_rtc_resume(struct device *dev)
726 {
727 struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
728
729 if (device_may_wakeup(dev))
730 disable_irq_wake(chip->irq);
731
732 return 0;
733 }
734 #endif
735
736 static SIMPLE_DEV_PM_OPS(sun6i_rtc_pm_ops,
737 sun6i_rtc_suspend, sun6i_rtc_resume);
738
sun6i_rtc_bus_clk_cleanup(void * data)739 static void sun6i_rtc_bus_clk_cleanup(void *data)
740 {
741 struct clk *bus_clk = data;
742
743 clk_disable_unprepare(bus_clk);
744 }
745
sun6i_rtc_probe(struct platform_device * pdev)746 static int sun6i_rtc_probe(struct platform_device *pdev)
747 {
748 struct sun6i_rtc_dev *chip = sun6i_rtc;
749 struct device *dev = &pdev->dev;
750 struct clk *bus_clk;
751 int ret;
752
753 bus_clk = devm_clk_get_optional(dev, "bus");
754 if (IS_ERR(bus_clk))
755 return PTR_ERR(bus_clk);
756
757 if (bus_clk) {
758 ret = clk_prepare_enable(bus_clk);
759 if (ret)
760 return ret;
761
762 ret = devm_add_action_or_reset(dev, sun6i_rtc_bus_clk_cleanup,
763 bus_clk);
764 if (ret)
765 return ret;
766 }
767
768 if (!chip) {
769 chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
770 if (!chip)
771 return -ENOMEM;
772
773 spin_lock_init(&chip->lock);
774
775 chip->base = devm_platform_ioremap_resource(pdev, 0);
776 if (IS_ERR(chip->base))
777 return PTR_ERR(chip->base);
778
779 if (IS_REACHABLE(CONFIG_SUN6I_RTC_CCU)) {
780 ret = sun6i_rtc_ccu_probe(dev, chip->base);
781 if (ret)
782 return ret;
783 }
784 }
785
786 platform_set_drvdata(pdev, chip);
787
788 chip->flags = (unsigned long)of_device_get_match_data(&pdev->dev);
789
790 chip->irq = platform_get_irq(pdev, 0);
791 if (chip->irq < 0)
792 return chip->irq;
793
794 ret = devm_request_irq(&pdev->dev, chip->irq, sun6i_rtc_alarmirq,
795 0, dev_name(&pdev->dev), chip);
796 if (ret) {
797 dev_err(&pdev->dev, "Could not request IRQ\n");
798 return ret;
799 }
800
801 /* clear the alarm counter value */
802 writel(0, chip->base + SUN6I_ALRM_COUNTER);
803
804 /* disable counter alarm */
805 writel(0, chip->base + SUN6I_ALRM_EN);
806
807 /* disable counter alarm interrupt */
808 writel(0, chip->base + SUN6I_ALRM_IRQ_EN);
809
810 /* disable week alarm */
811 writel(0, chip->base + SUN6I_ALRM1_EN);
812
813 /* disable week alarm interrupt */
814 writel(0, chip->base + SUN6I_ALRM1_IRQ_EN);
815
816 /* clear counter alarm pending interrupts */
817 writel(SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND,
818 chip->base + SUN6I_ALRM_IRQ_STA);
819
820 /* clear week alarm pending interrupts */
821 writel(SUN6I_ALRM1_IRQ_STA_WEEK_IRQ_PEND,
822 chip->base + SUN6I_ALRM1_IRQ_STA);
823
824 /* disable alarm wakeup */
825 writel(0, chip->base + SUN6I_ALARM_CONFIG);
826
827 clk_prepare_enable(chip->losc);
828
829 device_init_wakeup(&pdev->dev, 1);
830
831 chip->rtc = devm_rtc_allocate_device(&pdev->dev);
832 if (IS_ERR(chip->rtc))
833 return PTR_ERR(chip->rtc);
834
835 chip->rtc->ops = &sun6i_rtc_ops;
836 if (chip->flags & RTC_LINEAR_DAY)
837 chip->rtc->range_max = (65536 * SECS_PER_DAY) - 1;
838 else
839 chip->rtc->range_max = 2019686399LL; /* 2033-12-31 23:59:59 */
840
841 ret = devm_rtc_register_device(chip->rtc);
842 if (ret)
843 return ret;
844
845 sun6i_rtc_nvmem_cfg.priv = chip;
846 ret = devm_rtc_nvmem_register(chip->rtc, &sun6i_rtc_nvmem_cfg);
847 if (ret)
848 return ret;
849
850 return 0;
851 }
852
853 /*
854 * As far as RTC functionality goes, all models are the same. The
855 * datasheets claim that different models have different number of
856 * registers available for non-volatile storage, but experiments show
857 * that all SoCs have 16 registers available for this purpose.
858 */
859 static const struct of_device_id sun6i_rtc_dt_ids[] = {
860 { .compatible = "allwinner,sun6i-a31-rtc" },
861 { .compatible = "allwinner,sun8i-a23-rtc" },
862 { .compatible = "allwinner,sun8i-h3-rtc" },
863 { .compatible = "allwinner,sun8i-r40-rtc" },
864 { .compatible = "allwinner,sun8i-v3-rtc" },
865 { .compatible = "allwinner,sun50i-h5-rtc" },
866 { .compatible = "allwinner,sun50i-h6-rtc" },
867 { .compatible = "allwinner,sun50i-h616-rtc",
868 .data = (void *)RTC_LINEAR_DAY },
869 { .compatible = "allwinner,sun50i-r329-rtc",
870 .data = (void *)RTC_LINEAR_DAY },
871 { /* sentinel */ },
872 };
873 MODULE_DEVICE_TABLE(of, sun6i_rtc_dt_ids);
874
875 static struct platform_driver sun6i_rtc_driver = {
876 .probe = sun6i_rtc_probe,
877 .driver = {
878 .name = "sun6i-rtc",
879 .of_match_table = sun6i_rtc_dt_ids,
880 .pm = &sun6i_rtc_pm_ops,
881 },
882 };
883 builtin_platform_driver(sun6i_rtc_driver);
884