Commit | Line | Data |
---|---|---|
d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
02964115 TH |
2 | /* |
3 | * A RTC driver for the Simtek STK17TA8 | |
4 | * | |
ab4364d3 | 5 | * By Thomas Hommel <thomas.hommel@ge.com> |
02964115 TH |
6 | * |
7 | * Based on the DS1553 driver from | |
8 | * Atsushi Nemoto <anemo@mba.ocn.ne.jp> | |
02964115 TH |
9 | */ |
10 | ||
11 | #include <linux/bcd.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/kernel.h> | |
5a0e3ad6 | 14 | #include <linux/gfp.h> |
02964115 TH |
15 | #include <linux/delay.h> |
16 | #include <linux/jiffies.h> | |
17 | #include <linux/interrupt.h> | |
18 | #include <linux/rtc.h> | |
19 | #include <linux/platform_device.h> | |
20 | #include <linux/io.h> | |
2113852b | 21 | #include <linux/module.h> |
02964115 | 22 | |
02964115 TH |
23 | #define RTC_REG_SIZE 0x20000 |
24 | #define RTC_OFFSET 0x1fff0 | |
25 | ||
26 | #define RTC_FLAGS (RTC_OFFSET + 0) | |
27 | #define RTC_CENTURY (RTC_OFFSET + 1) | |
28 | #define RTC_SECONDS_ALARM (RTC_OFFSET + 2) | |
29 | #define RTC_MINUTES_ALARM (RTC_OFFSET + 3) | |
30 | #define RTC_HOURS_ALARM (RTC_OFFSET + 4) | |
31 | #define RTC_DATE_ALARM (RTC_OFFSET + 5) | |
32 | #define RTC_INTERRUPTS (RTC_OFFSET + 6) | |
33 | #define RTC_WATCHDOG (RTC_OFFSET + 7) | |
34 | #define RTC_CALIBRATION (RTC_OFFSET + 8) | |
35 | #define RTC_SECONDS (RTC_OFFSET + 9) | |
36 | #define RTC_MINUTES (RTC_OFFSET + 10) | |
37 | #define RTC_HOURS (RTC_OFFSET + 11) | |
38 | #define RTC_DAY (RTC_OFFSET + 12) | |
39 | #define RTC_DATE (RTC_OFFSET + 13) | |
40 | #define RTC_MONTH (RTC_OFFSET + 14) | |
41 | #define RTC_YEAR (RTC_OFFSET + 15) | |
42 | ||
43 | #define RTC_SECONDS_MASK 0x7f | |
44 | #define RTC_DAY_MASK 0x07 | |
45 | #define RTC_CAL_MASK 0x3f | |
46 | ||
47 | /* Bits in the Calibration register */ | |
48 | #define RTC_STOP 0x80 | |
49 | ||
50 | /* Bits in the Flags register */ | |
51 | #define RTC_FLAGS_AF 0x40 | |
52 | #define RTC_FLAGS_PF 0x20 | |
53 | #define RTC_WRITE 0x02 | |
54 | #define RTC_READ 0x01 | |
55 | ||
56 | /* Bits in the Interrupts register */ | |
57 | #define RTC_INTS_AIE 0x40 | |
58 | ||
59 | struct rtc_plat_data { | |
60 | struct rtc_device *rtc; | |
61 | void __iomem *ioaddr; | |
02964115 TH |
62 | unsigned long last_jiffies; |
63 | int irq; | |
64 | unsigned int irqen; | |
65 | int alrm_sec; | |
66 | int alrm_min; | |
67 | int alrm_hour; | |
68 | int alrm_mday; | |
3151520d | 69 | spinlock_t lock; |
02964115 TH |
70 | }; |
71 | ||
72 | static int stk17ta8_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
73 | { | |
85368bb9 | 74 | struct rtc_plat_data *pdata = dev_get_drvdata(dev); |
02964115 TH |
75 | void __iomem *ioaddr = pdata->ioaddr; |
76 | u8 flags; | |
77 | ||
78 | flags = readb(pdata->ioaddr + RTC_FLAGS); | |
79 | writeb(flags | RTC_WRITE, pdata->ioaddr + RTC_FLAGS); | |
80 | ||
fe20ba70 AB |
81 | writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR); |
82 | writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH); | |
83 | writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY); | |
84 | writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE); | |
85 | writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS); | |
86 | writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES); | |
87 | writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS); | |
88 | writeb(bin2bcd((tm->tm_year + 1900) / 100), ioaddr + RTC_CENTURY); | |
02964115 TH |
89 | |
90 | writeb(flags & ~RTC_WRITE, pdata->ioaddr + RTC_FLAGS); | |
91 | return 0; | |
92 | } | |
93 | ||
94 | static int stk17ta8_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
95 | { | |
85368bb9 | 96 | struct rtc_plat_data *pdata = dev_get_drvdata(dev); |
02964115 TH |
97 | void __iomem *ioaddr = pdata->ioaddr; |
98 | unsigned int year, month, day, hour, minute, second, week; | |
99 | unsigned int century; | |
100 | u8 flags; | |
101 | ||
102 | /* give enough time to update RTC in case of continuous read */ | |
103 | if (pdata->last_jiffies == jiffies) | |
104 | msleep(1); | |
105 | pdata->last_jiffies = jiffies; | |
106 | ||
107 | flags = readb(pdata->ioaddr + RTC_FLAGS); | |
108 | writeb(flags | RTC_READ, ioaddr + RTC_FLAGS); | |
109 | second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK; | |
110 | minute = readb(ioaddr + RTC_MINUTES); | |
111 | hour = readb(ioaddr + RTC_HOURS); | |
112 | day = readb(ioaddr + RTC_DATE); | |
113 | week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK; | |
114 | month = readb(ioaddr + RTC_MONTH); | |
115 | year = readb(ioaddr + RTC_YEAR); | |
116 | century = readb(ioaddr + RTC_CENTURY); | |
117 | writeb(flags & ~RTC_READ, ioaddr + RTC_FLAGS); | |
fe20ba70 AB |
118 | tm->tm_sec = bcd2bin(second); |
119 | tm->tm_min = bcd2bin(minute); | |
120 | tm->tm_hour = bcd2bin(hour); | |
121 | tm->tm_mday = bcd2bin(day); | |
122 | tm->tm_wday = bcd2bin(week); | |
123 | tm->tm_mon = bcd2bin(month) - 1; | |
02964115 | 124 | /* year is 1900 + tm->tm_year */ |
fe20ba70 | 125 | tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900; |
02964115 | 126 | |
02964115 TH |
127 | return 0; |
128 | } | |
129 | ||
130 | static void stk17ta8_rtc_update_alarm(struct rtc_plat_data *pdata) | |
131 | { | |
132 | void __iomem *ioaddr = pdata->ioaddr; | |
133 | unsigned long irqflags; | |
134 | u8 flags; | |
135 | ||
3151520d | 136 | spin_lock_irqsave(&pdata->lock, irqflags); |
02964115 TH |
137 | |
138 | flags = readb(ioaddr + RTC_FLAGS); | |
139 | writeb(flags | RTC_WRITE, ioaddr + RTC_FLAGS); | |
140 | ||
141 | writeb(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ? | |
fe20ba70 | 142 | 0x80 : bin2bcd(pdata->alrm_mday), |
02964115 TH |
143 | ioaddr + RTC_DATE_ALARM); |
144 | writeb(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ? | |
fe20ba70 | 145 | 0x80 : bin2bcd(pdata->alrm_hour), |
02964115 TH |
146 | ioaddr + RTC_HOURS_ALARM); |
147 | writeb(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ? | |
fe20ba70 | 148 | 0x80 : bin2bcd(pdata->alrm_min), |
02964115 TH |
149 | ioaddr + RTC_MINUTES_ALARM); |
150 | writeb(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ? | |
fe20ba70 | 151 | 0x80 : bin2bcd(pdata->alrm_sec), |
02964115 TH |
152 | ioaddr + RTC_SECONDS_ALARM); |
153 | writeb(pdata->irqen ? RTC_INTS_AIE : 0, ioaddr + RTC_INTERRUPTS); | |
154 | readb(ioaddr + RTC_FLAGS); /* clear interrupts */ | |
155 | writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS); | |
3151520d | 156 | spin_unlock_irqrestore(&pdata->lock, irqflags); |
02964115 TH |
157 | } |
158 | ||
159 | static int stk17ta8_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) | |
160 | { | |
85368bb9 | 161 | struct rtc_plat_data *pdata = dev_get_drvdata(dev); |
02964115 | 162 | |
2fac6674 | 163 | if (pdata->irq <= 0) |
02964115 TH |
164 | return -EINVAL; |
165 | pdata->alrm_mday = alrm->time.tm_mday; | |
166 | pdata->alrm_hour = alrm->time.tm_hour; | |
167 | pdata->alrm_min = alrm->time.tm_min; | |
168 | pdata->alrm_sec = alrm->time.tm_sec; | |
169 | if (alrm->enabled) | |
170 | pdata->irqen |= RTC_AF; | |
171 | stk17ta8_rtc_update_alarm(pdata); | |
172 | return 0; | |
173 | } | |
174 | ||
175 | static int stk17ta8_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) | |
176 | { | |
85368bb9 | 177 | struct rtc_plat_data *pdata = dev_get_drvdata(dev); |
02964115 | 178 | |
2fac6674 | 179 | if (pdata->irq <= 0) |
02964115 TH |
180 | return -EINVAL; |
181 | alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday; | |
182 | alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour; | |
183 | alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min; | |
184 | alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec; | |
185 | alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0; | |
186 | return 0; | |
187 | } | |
188 | ||
189 | static irqreturn_t stk17ta8_rtc_interrupt(int irq, void *dev_id) | |
190 | { | |
191 | struct platform_device *pdev = dev_id; | |
192 | struct rtc_plat_data *pdata = platform_get_drvdata(pdev); | |
193 | void __iomem *ioaddr = pdata->ioaddr; | |
3151520d | 194 | unsigned long events = 0; |
02964115 | 195 | |
3151520d | 196 | spin_lock(&pdata->lock); |
02964115 | 197 | /* read and clear interrupt */ |
3151520d AN |
198 | if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) { |
199 | events = RTC_IRQF; | |
200 | if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80) | |
201 | events |= RTC_UF; | |
202 | else | |
203 | events |= RTC_AF; | |
0d71915d | 204 | rtc_update_irq(pdata->rtc, 1, events); |
3151520d AN |
205 | } |
206 | spin_unlock(&pdata->lock); | |
207 | return events ? IRQ_HANDLED : IRQ_NONE; | |
02964115 TH |
208 | } |
209 | ||
3151520d AN |
210 | static int stk17ta8_rtc_alarm_irq_enable(struct device *dev, |
211 | unsigned int enabled) | |
02964115 | 212 | { |
85368bb9 | 213 | struct rtc_plat_data *pdata = dev_get_drvdata(dev); |
02964115 | 214 | |
2fac6674 | 215 | if (pdata->irq <= 0) |
3151520d AN |
216 | return -EINVAL; |
217 | if (enabled) | |
02964115 | 218 | pdata->irqen |= RTC_AF; |
3151520d AN |
219 | else |
220 | pdata->irqen &= ~RTC_AF; | |
221 | stk17ta8_rtc_update_alarm(pdata); | |
02964115 TH |
222 | return 0; |
223 | } | |
224 | ||
225 | static const struct rtc_class_ops stk17ta8_rtc_ops = { | |
3151520d AN |
226 | .read_time = stk17ta8_rtc_read_time, |
227 | .set_time = stk17ta8_rtc_set_time, | |
228 | .read_alarm = stk17ta8_rtc_read_alarm, | |
229 | .set_alarm = stk17ta8_rtc_set_alarm, | |
230 | .alarm_irq_enable = stk17ta8_rtc_alarm_irq_enable, | |
02964115 TH |
231 | }; |
232 | ||
d7ca4299 AB |
233 | static int stk17ta8_nvram_read(void *priv, unsigned int pos, void *val, |
234 | size_t bytes) | |
02964115 | 235 | { |
d7ca4299 | 236 | struct rtc_plat_data *pdata = priv; |
02964115 | 237 | void __iomem *ioaddr = pdata->ioaddr; |
d7ca4299 | 238 | u8 *buf = val; |
02964115 | 239 | |
d7ca4299 | 240 | for (; bytes; bytes--) |
02964115 | 241 | *buf++ = readb(ioaddr + pos++); |
d7ca4299 | 242 | return 0; |
02964115 TH |
243 | } |
244 | ||
d7ca4299 AB |
245 | static int stk17ta8_nvram_write(void *priv, unsigned int pos, void *val, |
246 | size_t bytes) | |
02964115 | 247 | { |
d7ca4299 | 248 | struct rtc_plat_data *pdata = priv; |
02964115 | 249 | void __iomem *ioaddr = pdata->ioaddr; |
d7ca4299 | 250 | u8 *buf = val; |
02964115 | 251 | |
d7ca4299 | 252 | for (; bytes; bytes--) |
02964115 | 253 | writeb(*buf++, ioaddr + pos++); |
d7ca4299 | 254 | return 0; |
02964115 TH |
255 | } |
256 | ||
5a167f45 | 257 | static int stk17ta8_rtc_probe(struct platform_device *pdev) |
02964115 | 258 | { |
02964115 TH |
259 | struct resource *res; |
260 | unsigned int cal; | |
261 | unsigned int flags; | |
262 | struct rtc_plat_data *pdata; | |
3151520d | 263 | void __iomem *ioaddr; |
02964115 | 264 | int ret = 0; |
d7ca4299 AB |
265 | struct nvmem_config nvmem_cfg = { |
266 | .name = "stk17ta8_nvram", | |
267 | .word_size = 1, | |
268 | .stride = 1, | |
269 | .size = RTC_OFFSET, | |
270 | .reg_read = stk17ta8_nvram_read, | |
271 | .reg_write = stk17ta8_nvram_write, | |
272 | }; | |
02964115 | 273 | |
3151520d | 274 | pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); |
02964115 TH |
275 | if (!pdata) |
276 | return -ENOMEM; | |
7c1d69ee JL |
277 | |
278 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
279 | ioaddr = devm_ioremap_resource(&pdev->dev, res); | |
280 | if (IS_ERR(ioaddr)) | |
281 | return PTR_ERR(ioaddr); | |
02964115 TH |
282 | pdata->ioaddr = ioaddr; |
283 | pdata->irq = platform_get_irq(pdev, 0); | |
284 | ||
285 | /* turn RTC on if it was not on */ | |
286 | cal = readb(ioaddr + RTC_CALIBRATION); | |
287 | if (cal & RTC_STOP) { | |
288 | cal &= RTC_CAL_MASK; | |
289 | flags = readb(ioaddr + RTC_FLAGS); | |
290 | writeb(flags | RTC_WRITE, ioaddr + RTC_FLAGS); | |
291 | writeb(cal, ioaddr + RTC_CALIBRATION); | |
292 | writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS); | |
293 | } | |
294 | if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_PF) | |
295 | dev_warn(&pdev->dev, "voltage-low detected.\n"); | |
296 | ||
3151520d AN |
297 | spin_lock_init(&pdata->lock); |
298 | pdata->last_jiffies = jiffies; | |
299 | platform_set_drvdata(pdev, pdata); | |
2fac6674 | 300 | if (pdata->irq > 0) { |
02964115 | 301 | writeb(0, ioaddr + RTC_INTERRUPTS); |
3151520d AN |
302 | if (devm_request_irq(&pdev->dev, pdata->irq, |
303 | stk17ta8_rtc_interrupt, | |
2f6e5f94 | 304 | IRQF_SHARED, |
02964115 TH |
305 | pdev->name, pdev) < 0) { |
306 | dev_warn(&pdev->dev, "interrupt not available.\n"); | |
2fac6674 | 307 | pdata->irq = 0; |
02964115 TH |
308 | } |
309 | } | |
310 | ||
91cb6774 | 311 | pdata->rtc = devm_rtc_allocate_device(&pdev->dev); |
3151520d AN |
312 | if (IS_ERR(pdata->rtc)) |
313 | return PTR_ERR(pdata->rtc); | |
b74d2caa | 314 | |
91cb6774 | 315 | pdata->rtc->ops = &stk17ta8_rtc_ops; |
d7ca4299 | 316 | pdata->rtc->nvram_old_abi = true; |
91cb6774 | 317 | |
d7ca4299 AB |
318 | nvmem_cfg.priv = pdata; |
319 | ret = rtc_nvmem_register(pdata->rtc, &nvmem_cfg); | |
91cb6774 AB |
320 | if (ret) |
321 | return ret; | |
322 | ||
d7ca4299 | 323 | return rtc_register_device(pdata->rtc); |
02964115 TH |
324 | } |
325 | ||
ad28a07b KS |
326 | /* work with hotplug and coldplug */ |
327 | MODULE_ALIAS("platform:stk17ta8"); | |
328 | ||
02964115 TH |
329 | static struct platform_driver stk17ta8_rtc_driver = { |
330 | .probe = stk17ta8_rtc_probe, | |
02964115 TH |
331 | .driver = { |
332 | .name = "stk17ta8", | |
02964115 TH |
333 | }, |
334 | }; | |
335 | ||
0c4eae66 | 336 | module_platform_driver(stk17ta8_rtc_driver); |
02964115 | 337 | |
ab4364d3 | 338 | MODULE_AUTHOR("Thomas Hommel <thomas.hommel@ge.com>"); |
02964115 TH |
339 | MODULE_DESCRIPTION("Simtek STK17TA8 RTC driver"); |
340 | MODULE_LICENSE("GPL"); |