1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Loongson RTC driver |
4 | * |
5 | * Maintained out-of-tree by Huacai Chen <chenhuacai@kernel.org>. |
6 | * Rewritten for mainline by WANG Xuerui <git@xen0n.name>. |
7 | * Binbin Zhou <zhoubinbin@loongson.cn> |
8 | */ |
9 | |
10 | #include <linux/bitfield.h> |
11 | #include <linux/kernel.h> |
12 | #include <linux/module.h> |
13 | #include <linux/platform_device.h> |
14 | #include <linux/regmap.h> |
15 | #include <linux/rtc.h> |
16 | #include <linux/acpi.h> |
17 | |
18 | /* Time Of Year(TOY) counters registers */ |
19 | #define TOY_TRIM_REG 0x20 /* Must be initialized to 0 */ |
20 | #define TOY_WRITE0_REG 0x24 /* TOY low 32-bits value (write-only) */ |
21 | #define TOY_WRITE1_REG 0x28 /* TOY high 32-bits value (write-only) */ |
22 | #define TOY_READ0_REG 0x2c /* TOY low 32-bits value (read-only) */ |
23 | #define TOY_READ1_REG 0x30 /* TOY high 32-bits value (read-only) */ |
24 | #define TOY_MATCH0_REG 0x34 /* TOY timing interrupt 0 */ |
25 | #define TOY_MATCH1_REG 0x38 /* TOY timing interrupt 1 */ |
26 | #define TOY_MATCH2_REG 0x3c /* TOY timing interrupt 2 */ |
27 | |
28 | /* RTC counters registers */ |
29 | #define RTC_CTRL_REG 0x40 /* TOY and RTC control register */ |
30 | #define RTC_TRIM_REG 0x60 /* Must be initialized to 0 */ |
31 | #define RTC_WRITE0_REG 0x64 /* RTC counters value (write-only) */ |
32 | #define RTC_READ0_REG 0x68 /* RTC counters value (read-only) */ |
33 | #define RTC_MATCH0_REG 0x6c /* RTC timing interrupt 0 */ |
34 | #define RTC_MATCH1_REG 0x70 /* RTC timing interrupt 1 */ |
35 | #define RTC_MATCH2_REG 0x74 /* RTC timing interrupt 2 */ |
36 | |
37 | /* bitmask of TOY_WRITE0_REG */ |
38 | #define TOY_MON GENMASK(31, 26) |
39 | #define TOY_DAY GENMASK(25, 21) |
40 | #define TOY_HOUR GENMASK(20, 16) |
41 | #define TOY_MIN GENMASK(15, 10) |
42 | #define TOY_SEC GENMASK(9, 4) |
43 | #define TOY_MSEC GENMASK(3, 0) |
44 | |
45 | /* bitmask of TOY_MATCH0/1/2_REG */ |
46 | #define TOY_MATCH_YEAR GENMASK(31, 26) |
47 | #define TOY_MATCH_MON GENMASK(25, 22) |
48 | #define TOY_MATCH_DAY GENMASK(21, 17) |
49 | #define TOY_MATCH_HOUR GENMASK(16, 12) |
50 | #define TOY_MATCH_MIN GENMASK(11, 6) |
51 | #define TOY_MATCH_SEC GENMASK(5, 0) |
52 | |
53 | /* bitmask of RTC_CTRL_REG */ |
54 | #define RTC_ENABLE BIT(13) /* 1: RTC counters enable */ |
55 | #define TOY_ENABLE BIT(11) /* 1: TOY counters enable */ |
56 | #define OSC_ENABLE BIT(8) /* 1: 32.768k crystal enable */ |
57 | #define TOY_ENABLE_MASK (TOY_ENABLE | OSC_ENABLE) |
58 | |
59 | /* PM domain registers */ |
60 | #define PM1_STS_REG 0x0c /* Power management 1 status register */ |
61 | #define RTC_STS BIT(10) /* RTC status */ |
62 | #define PM1_EN_REG 0x10 /* Power management 1 enable register */ |
63 | #define RTC_EN BIT(10) /* RTC event enable */ |
64 | |
65 | /* |
66 | * According to the LS1C manual, RTC_CTRL and alarm-related registers are not defined. |
67 | * Accessing the relevant registers will cause the system to hang. |
68 | */ |
69 | #define LS1C_RTC_CTRL_WORKAROUND BIT(0) |
70 | |
71 | struct loongson_rtc_config { |
72 | u32 pm_offset; /* Offset of PM domain, for RTC alarm wakeup */ |
73 | u32 flags; /* Workaround bits */ |
74 | }; |
75 | |
76 | struct loongson_rtc_priv { |
77 | spinlock_t lock; /* protects PM registers access */ |
78 | u32 fix_year; /* RTC alarm year compensation value */ |
79 | struct rtc_device *rtcdev; |
80 | struct regmap *regmap; |
81 | void __iomem *pm_base; /* PM domain base, for RTC alarm wakeup */ |
82 | const struct loongson_rtc_config *config; |
83 | }; |
84 | |
85 | static const struct loongson_rtc_config ls1b_rtc_config = { |
86 | .pm_offset = 0, |
87 | .flags = 0, |
88 | }; |
89 | |
90 | static const struct loongson_rtc_config ls1c_rtc_config = { |
91 | .pm_offset = 0, |
92 | .flags = LS1C_RTC_CTRL_WORKAROUND, |
93 | }; |
94 | |
95 | static const struct loongson_rtc_config generic_rtc_config = { |
96 | .pm_offset = 0x100, |
97 | .flags = 0, |
98 | }; |
99 | |
100 | static const struct loongson_rtc_config ls2k1000_rtc_config = { |
101 | .pm_offset = 0x800, |
102 | .flags = 0, |
103 | }; |
104 | |
105 | static const struct regmap_config loongson_rtc_regmap_config = { |
106 | .reg_bits = 32, |
107 | .val_bits = 32, |
108 | .reg_stride = 4, |
109 | }; |
110 | |
111 | /* RTC alarm irq handler */ |
112 | static irqreturn_t loongson_rtc_isr(int irq, void *id) |
113 | { |
114 | struct loongson_rtc_priv *priv = (struct loongson_rtc_priv *)id; |
115 | |
116 | rtc_update_irq(rtc: priv->rtcdev, num: 1, RTC_AF | RTC_IRQF); |
117 | return IRQ_HANDLED; |
118 | } |
119 | |
120 | /* For ACPI fixed event handler */ |
121 | static u32 loongson_rtc_handler(void *id) |
122 | { |
123 | struct loongson_rtc_priv *priv = (struct loongson_rtc_priv *)id; |
124 | |
125 | spin_lock(lock: &priv->lock); |
126 | /* Disable RTC alarm wakeup and interrupt */ |
127 | writel(readl(addr: priv->pm_base + PM1_EN_REG) & ~RTC_EN, |
128 | addr: priv->pm_base + PM1_EN_REG); |
129 | |
130 | /* Clear RTC interrupt status */ |
131 | writel(RTC_STS, addr: priv->pm_base + PM1_STS_REG); |
132 | spin_unlock(lock: &priv->lock); |
133 | |
134 | /* |
135 | * The TOY_MATCH0_REG should be cleared 0 here, |
136 | * otherwise the interrupt cannot be cleared. |
137 | */ |
138 | return regmap_write(map: priv->regmap, TOY_MATCH0_REG, val: 0); |
139 | } |
140 | |
141 | static int loongson_rtc_set_enabled(struct device *dev) |
142 | { |
143 | struct loongson_rtc_priv *priv = dev_get_drvdata(dev); |
144 | |
145 | if (priv->config->flags & LS1C_RTC_CTRL_WORKAROUND) |
146 | return 0; |
147 | |
148 | /* Enable RTC TOY counters and crystal */ |
149 | return regmap_update_bits(map: priv->regmap, RTC_CTRL_REG, TOY_ENABLE_MASK, |
150 | TOY_ENABLE_MASK); |
151 | } |
152 | |
153 | static bool loongson_rtc_get_enabled(struct device *dev) |
154 | { |
155 | int ret; |
156 | u32 ctrl_data; |
157 | struct loongson_rtc_priv *priv = dev_get_drvdata(dev); |
158 | |
159 | if (priv->config->flags & LS1C_RTC_CTRL_WORKAROUND) |
160 | return true; |
161 | |
162 | ret = regmap_read(map: priv->regmap, RTC_CTRL_REG, val: &ctrl_data); |
163 | if (ret < 0) |
164 | return false; |
165 | |
166 | return ctrl_data & TOY_ENABLE_MASK; |
167 | } |
168 | |
169 | static int loongson_rtc_read_time(struct device *dev, struct rtc_time *tm) |
170 | { |
171 | int ret; |
172 | u32 rtc_data[2]; |
173 | struct loongson_rtc_priv *priv = dev_get_drvdata(dev); |
174 | |
175 | if (!loongson_rtc_get_enabled(dev)) |
176 | return -EINVAL; |
177 | |
178 | ret = regmap_bulk_read(map: priv->regmap, TOY_READ0_REG, val: rtc_data, |
179 | ARRAY_SIZE(rtc_data)); |
180 | if (ret < 0) |
181 | return ret; |
182 | |
183 | tm->tm_sec = FIELD_GET(TOY_SEC, rtc_data[0]); |
184 | tm->tm_min = FIELD_GET(TOY_MIN, rtc_data[0]); |
185 | tm->tm_hour = FIELD_GET(TOY_HOUR, rtc_data[0]); |
186 | tm->tm_mday = FIELD_GET(TOY_DAY, rtc_data[0]); |
187 | tm->tm_mon = FIELD_GET(TOY_MON, rtc_data[0]) - 1; |
188 | tm->tm_year = rtc_data[1]; |
189 | |
190 | /* Prepare for RTC alarm year compensation value. */ |
191 | priv->fix_year = tm->tm_year / 64 * 64; |
192 | return 0; |
193 | } |
194 | |
195 | static int loongson_rtc_set_time(struct device *dev, struct rtc_time *tm) |
196 | { |
197 | int ret; |
198 | u32 rtc_data[2]; |
199 | struct loongson_rtc_priv *priv = dev_get_drvdata(dev); |
200 | |
201 | rtc_data[0] = FIELD_PREP(TOY_SEC, tm->tm_sec) |
202 | | FIELD_PREP(TOY_MIN, tm->tm_min) |
203 | | FIELD_PREP(TOY_HOUR, tm->tm_hour) |
204 | | FIELD_PREP(TOY_DAY, tm->tm_mday) |
205 | | FIELD_PREP(TOY_MON, tm->tm_mon + 1); |
206 | rtc_data[1] = tm->tm_year; |
207 | |
208 | ret = regmap_bulk_write(map: priv->regmap, TOY_WRITE0_REG, val: rtc_data, |
209 | ARRAY_SIZE(rtc_data)); |
210 | if (ret < 0) |
211 | return ret; |
212 | |
213 | return loongson_rtc_set_enabled(dev); |
214 | } |
215 | |
216 | static int loongson_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) |
217 | { |
218 | int ret; |
219 | u32 alarm_data; |
220 | struct loongson_rtc_priv *priv = dev_get_drvdata(dev); |
221 | |
222 | ret = regmap_read(map: priv->regmap, TOY_MATCH0_REG, val: &alarm_data); |
223 | if (ret < 0) |
224 | return ret; |
225 | |
226 | alrm->time.tm_sec = FIELD_GET(TOY_MATCH_SEC, alarm_data); |
227 | alrm->time.tm_min = FIELD_GET(TOY_MATCH_MIN, alarm_data); |
228 | alrm->time.tm_hour = FIELD_GET(TOY_MATCH_HOUR, alarm_data); |
229 | alrm->time.tm_mday = FIELD_GET(TOY_MATCH_DAY, alarm_data); |
230 | alrm->time.tm_mon = FIELD_GET(TOY_MATCH_MON, alarm_data) - 1; |
231 | /* |
232 | * This is a hardware bug: the year field of SYS_TOYMATCH is only 6 bits, |
233 | * making it impossible to save year values larger than 64. |
234 | * |
235 | * SYS_TOYMATCH is used to match the alarm time value and determine if |
236 | * an alarm is triggered, so we must keep the lower 6 bits of the year |
237 | * value constant during the value conversion. |
238 | * |
239 | * In summary, we need to manually add 64(or a multiple of 64) to the |
240 | * year value to avoid the invalid alarm prompt at startup. |
241 | */ |
242 | alrm->time.tm_year = FIELD_GET(TOY_MATCH_YEAR, alarm_data) + priv->fix_year; |
243 | |
244 | alrm->enabled = !!(readl(addr: priv->pm_base + PM1_EN_REG) & RTC_EN); |
245 | return 0; |
246 | } |
247 | |
248 | static int loongson_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) |
249 | { |
250 | u32 val; |
251 | struct loongson_rtc_priv *priv = dev_get_drvdata(dev); |
252 | |
253 | spin_lock(lock: &priv->lock); |
254 | val = readl(addr: priv->pm_base + PM1_EN_REG); |
255 | /* Enable RTC alarm wakeup */ |
256 | writel(val: enabled ? val | RTC_EN : val & ~RTC_EN, |
257 | addr: priv->pm_base + PM1_EN_REG); |
258 | spin_unlock(lock: &priv->lock); |
259 | |
260 | return 0; |
261 | } |
262 | |
263 | static int loongson_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) |
264 | { |
265 | int ret; |
266 | u32 alarm_data; |
267 | struct loongson_rtc_priv *priv = dev_get_drvdata(dev); |
268 | |
269 | alarm_data = FIELD_PREP(TOY_MATCH_SEC, alrm->time.tm_sec) |
270 | | FIELD_PREP(TOY_MATCH_MIN, alrm->time.tm_min) |
271 | | FIELD_PREP(TOY_MATCH_HOUR, alrm->time.tm_hour) |
272 | | FIELD_PREP(TOY_MATCH_DAY, alrm->time.tm_mday) |
273 | | FIELD_PREP(TOY_MATCH_MON, alrm->time.tm_mon + 1) |
274 | | FIELD_PREP(TOY_MATCH_YEAR, alrm->time.tm_year - priv->fix_year); |
275 | |
276 | ret = regmap_write(map: priv->regmap, TOY_MATCH0_REG, val: alarm_data); |
277 | if (ret < 0) |
278 | return ret; |
279 | |
280 | return loongson_rtc_alarm_irq_enable(dev, enabled: alrm->enabled); |
281 | } |
282 | |
283 | static const struct rtc_class_ops loongson_rtc_ops = { |
284 | .read_time = loongson_rtc_read_time, |
285 | .set_time = loongson_rtc_set_time, |
286 | .read_alarm = loongson_rtc_read_alarm, |
287 | .set_alarm = loongson_rtc_set_alarm, |
288 | .alarm_irq_enable = loongson_rtc_alarm_irq_enable, |
289 | }; |
290 | |
291 | static int loongson_rtc_probe(struct platform_device *pdev) |
292 | { |
293 | int ret, alarm_irq; |
294 | void __iomem *regs; |
295 | struct loongson_rtc_priv *priv; |
296 | struct device *dev = &pdev->dev; |
297 | |
298 | priv = devm_kzalloc(dev, size: sizeof(*priv), GFP_KERNEL); |
299 | if (!priv) |
300 | return -ENOMEM; |
301 | |
302 | regs = devm_platform_ioremap_resource(pdev, index: 0); |
303 | if (IS_ERR(ptr: regs)) |
304 | return dev_err_probe(dev, err: PTR_ERR(ptr: regs), |
305 | fmt: "devm_platform_ioremap_resource failed\n" ); |
306 | |
307 | priv->regmap = devm_regmap_init_mmio(dev, regs, |
308 | &loongson_rtc_regmap_config); |
309 | if (IS_ERR(ptr: priv->regmap)) |
310 | return dev_err_probe(dev, err: PTR_ERR(ptr: priv->regmap), |
311 | fmt: "devm_regmap_init_mmio failed\n" ); |
312 | |
313 | priv->config = device_get_match_data(dev); |
314 | spin_lock_init(&priv->lock); |
315 | platform_set_drvdata(pdev, data: priv); |
316 | |
317 | priv->rtcdev = devm_rtc_allocate_device(dev); |
318 | if (IS_ERR(ptr: priv->rtcdev)) |
319 | return dev_err_probe(dev, err: PTR_ERR(ptr: priv->rtcdev), |
320 | fmt: "devm_rtc_allocate_device failed\n" ); |
321 | |
322 | /* Get RTC alarm irq */ |
323 | alarm_irq = platform_get_irq(pdev, 0); |
324 | if (alarm_irq > 0) { |
325 | ret = devm_request_irq(dev, irq: alarm_irq, handler: loongson_rtc_isr, |
326 | irqflags: 0, devname: "loongson-alarm" , dev_id: priv); |
327 | if (ret < 0) |
328 | return dev_err_probe(dev, err: ret, fmt: "Unable to request irq %d\n" , |
329 | alarm_irq); |
330 | |
331 | priv->pm_base = regs - priv->config->pm_offset; |
332 | device_init_wakeup(dev, enable: 1); |
333 | |
334 | if (has_acpi_companion(dev)) |
335 | acpi_install_fixed_event_handler(ACPI_EVENT_RTC, |
336 | handler: loongson_rtc_handler, context: priv); |
337 | } else { |
338 | /* Loongson-1C RTC does not support alarm */ |
339 | clear_bit(RTC_FEATURE_ALARM, addr: priv->rtcdev->features); |
340 | } |
341 | |
342 | /* Loongson RTC does not support UIE */ |
343 | clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, addr: priv->rtcdev->features); |
344 | priv->rtcdev->ops = &loongson_rtc_ops; |
345 | priv->rtcdev->range_min = RTC_TIMESTAMP_BEGIN_2000; |
346 | priv->rtcdev->range_max = RTC_TIMESTAMP_END_2099; |
347 | |
348 | return devm_rtc_register_device(priv->rtcdev); |
349 | } |
350 | |
351 | static void loongson_rtc_remove(struct platform_device *pdev) |
352 | { |
353 | struct device *dev = &pdev->dev; |
354 | struct loongson_rtc_priv *priv = dev_get_drvdata(dev); |
355 | |
356 | if (!test_bit(RTC_FEATURE_ALARM, priv->rtcdev->features)) |
357 | return; |
358 | |
359 | if (has_acpi_companion(dev)) |
360 | acpi_remove_fixed_event_handler(ACPI_EVENT_RTC, |
361 | handler: loongson_rtc_handler); |
362 | |
363 | device_init_wakeup(dev, enable: 0); |
364 | loongson_rtc_alarm_irq_enable(dev, enabled: 0); |
365 | } |
366 | |
367 | static const struct of_device_id loongson_rtc_of_match[] = { |
368 | { .compatible = "loongson,ls1b-rtc" , .data = &ls1b_rtc_config }, |
369 | { .compatible = "loongson,ls1c-rtc" , .data = &ls1c_rtc_config }, |
370 | { .compatible = "loongson,ls7a-rtc" , .data = &generic_rtc_config }, |
371 | { .compatible = "loongson,ls2k1000-rtc" , .data = &ls2k1000_rtc_config }, |
372 | { /* sentinel */ } |
373 | }; |
374 | MODULE_DEVICE_TABLE(of, loongson_rtc_of_match); |
375 | |
376 | static const struct acpi_device_id loongson_rtc_acpi_match[] = { |
377 | { "LOON0001" , .driver_data = (kernel_ulong_t)&generic_rtc_config }, |
378 | { } |
379 | }; |
380 | MODULE_DEVICE_TABLE(acpi, loongson_rtc_acpi_match); |
381 | |
382 | static struct platform_driver loongson_rtc_driver = { |
383 | .probe = loongson_rtc_probe, |
384 | .remove_new = loongson_rtc_remove, |
385 | .driver = { |
386 | .name = "loongson-rtc" , |
387 | .of_match_table = loongson_rtc_of_match, |
388 | .acpi_match_table = loongson_rtc_acpi_match, |
389 | }, |
390 | }; |
391 | module_platform_driver(loongson_rtc_driver); |
392 | |
393 | MODULE_DESCRIPTION("Loongson RTC driver" ); |
394 | MODULE_AUTHOR("Binbin Zhou <zhoubinbin@loongson.cn>" ); |
395 | MODULE_AUTHOR("WANG Xuerui <git@xen0n.name>" ); |
396 | MODULE_AUTHOR("Huacai Chen <chenhuacai@kernel.org>" ); |
397 | MODULE_LICENSE("GPL" ); |
398 | |