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7dc679ef | 1 | // SPDX-License-Identifier: GPL-2.0 |
453b4c6d JJ |
2 | /* |
3 | * MOXA ART RTC driver. | |
4 | * | |
5 | * Copyright (C) 2013 Jonas Jensen | |
6 | * | |
7 | * Jonas Jensen <jonas.jensen@gmail.com> | |
8 | * | |
9 | * Based on code from | |
10 | * Moxa Technology Co., Ltd. <www.moxa.com> | |
453b4c6d JJ |
11 | */ |
12 | ||
13 | #include <linux/init.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/delay.h> | |
16 | #include <linux/rtc.h> | |
17 | #include <linux/platform_device.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/gpio.h> | |
20 | #include <linux/of_gpio.h> | |
21 | ||
22 | #define GPIO_RTC_RESERVED 0x0C | |
23 | #define GPIO_RTC_DATA_SET 0x10 | |
24 | #define GPIO_RTC_DATA_CLEAR 0x14 | |
25 | #define GPIO_RTC_PIN_PULL_ENABLE 0x18 | |
26 | #define GPIO_RTC_PIN_PULL_TYPE 0x1C | |
27 | #define GPIO_RTC_INT_ENABLE 0x20 | |
28 | #define GPIO_RTC_INT_RAW_STATE 0x24 | |
29 | #define GPIO_RTC_INT_MASKED_STATE 0x28 | |
30 | #define GPIO_RTC_INT_MASK 0x2C | |
31 | #define GPIO_RTC_INT_CLEAR 0x30 | |
32 | #define GPIO_RTC_INT_TRIGGER 0x34 | |
33 | #define GPIO_RTC_INT_BOTH 0x38 | |
34 | #define GPIO_RTC_INT_RISE_NEG 0x3C | |
35 | #define GPIO_RTC_BOUNCE_ENABLE 0x40 | |
36 | #define GPIO_RTC_BOUNCE_PRE_SCALE 0x44 | |
37 | #define GPIO_RTC_PROTECT_W 0x8E | |
38 | #define GPIO_RTC_PROTECT_R 0x8F | |
39 | #define GPIO_RTC_YEAR_W 0x8C | |
40 | #define GPIO_RTC_YEAR_R 0x8D | |
41 | #define GPIO_RTC_DAY_W 0x8A | |
42 | #define GPIO_RTC_DAY_R 0x8B | |
43 | #define GPIO_RTC_MONTH_W 0x88 | |
44 | #define GPIO_RTC_MONTH_R 0x89 | |
45 | #define GPIO_RTC_DATE_W 0x86 | |
46 | #define GPIO_RTC_DATE_R 0x87 | |
47 | #define GPIO_RTC_HOURS_W 0x84 | |
48 | #define GPIO_RTC_HOURS_R 0x85 | |
49 | #define GPIO_RTC_MINUTES_W 0x82 | |
50 | #define GPIO_RTC_MINUTES_R 0x83 | |
51 | #define GPIO_RTC_SECONDS_W 0x80 | |
52 | #define GPIO_RTC_SECONDS_R 0x81 | |
53 | #define GPIO_RTC_DELAY_TIME 8 | |
54 | ||
55 | struct moxart_rtc { | |
56 | struct rtc_device *rtc; | |
57 | spinlock_t rtc_lock; | |
58 | int gpio_data, gpio_sclk, gpio_reset; | |
59 | }; | |
60 | ||
61 | static int day_of_year[12] = { 0, 31, 59, 90, 120, 151, 181, | |
62 | 212, 243, 273, 304, 334 }; | |
63 | ||
64 | static void moxart_rtc_write_byte(struct device *dev, u8 data) | |
65 | { | |
66 | struct moxart_rtc *moxart_rtc = dev_get_drvdata(dev); | |
67 | int i; | |
68 | ||
69 | for (i = 0; i < 8; i++, data >>= 1) { | |
70 | gpio_set_value(moxart_rtc->gpio_sclk, 0); | |
71 | gpio_set_value(moxart_rtc->gpio_data, ((data & 1) == 1)); | |
72 | udelay(GPIO_RTC_DELAY_TIME); | |
73 | gpio_set_value(moxart_rtc->gpio_sclk, 1); | |
74 | udelay(GPIO_RTC_DELAY_TIME); | |
75 | } | |
76 | } | |
77 | ||
78 | static u8 moxart_rtc_read_byte(struct device *dev) | |
79 | { | |
80 | struct moxart_rtc *moxart_rtc = dev_get_drvdata(dev); | |
81 | int i; | |
82 | u8 data = 0; | |
83 | ||
84 | for (i = 0; i < 8; i++) { | |
85 | gpio_set_value(moxart_rtc->gpio_sclk, 0); | |
86 | udelay(GPIO_RTC_DELAY_TIME); | |
87 | gpio_set_value(moxart_rtc->gpio_sclk, 1); | |
88 | udelay(GPIO_RTC_DELAY_TIME); | |
89 | if (gpio_get_value(moxart_rtc->gpio_data)) | |
90 | data |= (1 << i); | |
91 | udelay(GPIO_RTC_DELAY_TIME); | |
92 | } | |
93 | return data; | |
94 | } | |
95 | ||
96 | static u8 moxart_rtc_read_register(struct device *dev, u8 cmd) | |
97 | { | |
98 | struct moxart_rtc *moxart_rtc = dev_get_drvdata(dev); | |
99 | u8 data; | |
100 | unsigned long flags; | |
101 | ||
102 | local_irq_save(flags); | |
103 | ||
104 | gpio_direction_output(moxart_rtc->gpio_data, 0); | |
105 | gpio_set_value(moxart_rtc->gpio_reset, 1); | |
106 | udelay(GPIO_RTC_DELAY_TIME); | |
107 | moxart_rtc_write_byte(dev, cmd); | |
108 | gpio_direction_input(moxart_rtc->gpio_data); | |
109 | udelay(GPIO_RTC_DELAY_TIME); | |
110 | data = moxart_rtc_read_byte(dev); | |
111 | gpio_set_value(moxart_rtc->gpio_sclk, 0); | |
112 | gpio_set_value(moxart_rtc->gpio_reset, 0); | |
113 | udelay(GPIO_RTC_DELAY_TIME); | |
114 | ||
115 | local_irq_restore(flags); | |
116 | ||
117 | return data; | |
118 | } | |
119 | ||
120 | static void moxart_rtc_write_register(struct device *dev, u8 cmd, u8 data) | |
121 | { | |
122 | struct moxart_rtc *moxart_rtc = dev_get_drvdata(dev); | |
123 | unsigned long flags; | |
124 | ||
125 | local_irq_save(flags); | |
126 | ||
127 | gpio_direction_output(moxart_rtc->gpio_data, 0); | |
128 | gpio_set_value(moxart_rtc->gpio_reset, 1); | |
129 | udelay(GPIO_RTC_DELAY_TIME); | |
130 | moxart_rtc_write_byte(dev, cmd); | |
131 | moxart_rtc_write_byte(dev, data); | |
132 | gpio_set_value(moxart_rtc->gpio_sclk, 0); | |
133 | gpio_set_value(moxart_rtc->gpio_reset, 0); | |
134 | udelay(GPIO_RTC_DELAY_TIME); | |
135 | ||
136 | local_irq_restore(flags); | |
137 | } | |
138 | ||
139 | static int moxart_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
140 | { | |
141 | struct moxart_rtc *moxart_rtc = dev_get_drvdata(dev); | |
142 | ||
143 | spin_lock_irq(&moxart_rtc->rtc_lock); | |
144 | ||
145 | moxart_rtc_write_register(dev, GPIO_RTC_PROTECT_W, 0); | |
146 | moxart_rtc_write_register(dev, GPIO_RTC_YEAR_W, | |
147 | (((tm->tm_year - 100) / 10) << 4) | | |
148 | ((tm->tm_year - 100) % 10)); | |
149 | ||
150 | moxart_rtc_write_register(dev, GPIO_RTC_MONTH_W, | |
151 | (((tm->tm_mon + 1) / 10) << 4) | | |
152 | ((tm->tm_mon + 1) % 10)); | |
153 | ||
154 | moxart_rtc_write_register(dev, GPIO_RTC_DATE_W, | |
155 | ((tm->tm_mday / 10) << 4) | | |
156 | (tm->tm_mday % 10)); | |
157 | ||
158 | moxart_rtc_write_register(dev, GPIO_RTC_HOURS_W, | |
159 | ((tm->tm_hour / 10) << 4) | | |
160 | (tm->tm_hour % 10)); | |
161 | ||
162 | moxart_rtc_write_register(dev, GPIO_RTC_MINUTES_W, | |
163 | ((tm->tm_min / 10) << 4) | | |
164 | (tm->tm_min % 10)); | |
165 | ||
166 | moxart_rtc_write_register(dev, GPIO_RTC_SECONDS_W, | |
167 | ((tm->tm_sec / 10) << 4) | | |
168 | (tm->tm_sec % 10)); | |
169 | ||
170 | moxart_rtc_write_register(dev, GPIO_RTC_PROTECT_W, 0x80); | |
171 | ||
172 | spin_unlock_irq(&moxart_rtc->rtc_lock); | |
173 | ||
174 | dev_dbg(dev, "%s: success tm_year=%d tm_mon=%d\n" | |
175 | "tm_mday=%d tm_hour=%d tm_min=%d tm_sec=%d\n", | |
176 | __func__, tm->tm_year, tm->tm_mon, tm->tm_mday, | |
177 | tm->tm_hour, tm->tm_min, tm->tm_sec); | |
178 | ||
179 | return 0; | |
180 | } | |
181 | ||
182 | static int moxart_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
183 | { | |
184 | struct moxart_rtc *moxart_rtc = dev_get_drvdata(dev); | |
185 | unsigned char v; | |
186 | ||
187 | spin_lock_irq(&moxart_rtc->rtc_lock); | |
188 | ||
189 | v = moxart_rtc_read_register(dev, GPIO_RTC_SECONDS_R); | |
190 | tm->tm_sec = (((v & 0x70) >> 4) * 10) + (v & 0x0F); | |
191 | ||
192 | v = moxart_rtc_read_register(dev, GPIO_RTC_MINUTES_R); | |
193 | tm->tm_min = (((v & 0x70) >> 4) * 10) + (v & 0x0F); | |
194 | ||
195 | v = moxart_rtc_read_register(dev, GPIO_RTC_HOURS_R); | |
196 | if (v & 0x80) { /* 12-hour mode */ | |
197 | tm->tm_hour = (((v & 0x10) >> 4) * 10) + (v & 0x0F); | |
198 | if (v & 0x20) { /* PM mode */ | |
199 | tm->tm_hour += 12; | |
200 | if (tm->tm_hour >= 24) | |
201 | tm->tm_hour = 0; | |
202 | } | |
203 | } else { /* 24-hour mode */ | |
204 | tm->tm_hour = (((v & 0x30) >> 4) * 10) + (v & 0x0F); | |
205 | } | |
206 | ||
207 | v = moxart_rtc_read_register(dev, GPIO_RTC_DATE_R); | |
208 | tm->tm_mday = (((v & 0x30) >> 4) * 10) + (v & 0x0F); | |
209 | ||
210 | v = moxart_rtc_read_register(dev, GPIO_RTC_MONTH_R); | |
211 | tm->tm_mon = (((v & 0x10) >> 4) * 10) + (v & 0x0F); | |
212 | tm->tm_mon--; | |
213 | ||
214 | v = moxart_rtc_read_register(dev, GPIO_RTC_YEAR_R); | |
215 | tm->tm_year = (((v & 0xF0) >> 4) * 10) + (v & 0x0F); | |
216 | tm->tm_year += 100; | |
217 | if (tm->tm_year <= 69) | |
218 | tm->tm_year += 100; | |
219 | ||
220 | v = moxart_rtc_read_register(dev, GPIO_RTC_DAY_R); | |
221 | tm->tm_wday = (v & 0x0f) - 1; | |
222 | tm->tm_yday = day_of_year[tm->tm_mon]; | |
223 | tm->tm_yday += (tm->tm_mday - 1); | |
224 | if (tm->tm_mon >= 2) { | |
225 | if (!(tm->tm_year % 4) && (tm->tm_year % 100)) | |
226 | tm->tm_yday++; | |
227 | } | |
228 | ||
229 | tm->tm_isdst = 0; | |
230 | ||
231 | spin_unlock_irq(&moxart_rtc->rtc_lock); | |
232 | ||
233 | return 0; | |
234 | } | |
235 | ||
236 | static const struct rtc_class_ops moxart_rtc_ops = { | |
237 | .read_time = moxart_rtc_read_time, | |
238 | .set_time = moxart_rtc_set_time, | |
239 | }; | |
240 | ||
241 | static int moxart_rtc_probe(struct platform_device *pdev) | |
242 | { | |
243 | struct moxart_rtc *moxart_rtc; | |
244 | int ret = 0; | |
245 | ||
246 | moxart_rtc = devm_kzalloc(&pdev->dev, sizeof(*moxart_rtc), GFP_KERNEL); | |
4410af6e | 247 | if (!moxart_rtc) |
453b4c6d | 248 | return -ENOMEM; |
453b4c6d JJ |
249 | |
250 | moxart_rtc->gpio_data = of_get_named_gpio(pdev->dev.of_node, | |
251 | "gpio-rtc-data", 0); | |
252 | if (!gpio_is_valid(moxart_rtc->gpio_data)) { | |
253 | dev_err(&pdev->dev, "invalid gpio (data): %d\n", | |
254 | moxart_rtc->gpio_data); | |
255 | return moxart_rtc->gpio_data; | |
256 | } | |
257 | ||
258 | moxart_rtc->gpio_sclk = of_get_named_gpio(pdev->dev.of_node, | |
259 | "gpio-rtc-sclk", 0); | |
260 | if (!gpio_is_valid(moxart_rtc->gpio_sclk)) { | |
261 | dev_err(&pdev->dev, "invalid gpio (sclk): %d\n", | |
262 | moxart_rtc->gpio_sclk); | |
263 | return moxart_rtc->gpio_sclk; | |
264 | } | |
265 | ||
266 | moxart_rtc->gpio_reset = of_get_named_gpio(pdev->dev.of_node, | |
267 | "gpio-rtc-reset", 0); | |
268 | if (!gpio_is_valid(moxart_rtc->gpio_reset)) { | |
269 | dev_err(&pdev->dev, "invalid gpio (reset): %d\n", | |
270 | moxart_rtc->gpio_reset); | |
271 | return moxart_rtc->gpio_reset; | |
272 | } | |
273 | ||
274 | spin_lock_init(&moxart_rtc->rtc_lock); | |
275 | platform_set_drvdata(pdev, moxart_rtc); | |
276 | ||
277 | ret = devm_gpio_request(&pdev->dev, moxart_rtc->gpio_data, "rtc_data"); | |
278 | if (ret) { | |
279 | dev_err(&pdev->dev, "can't get rtc_data gpio\n"); | |
280 | return ret; | |
281 | } | |
282 | ||
283 | ret = devm_gpio_request_one(&pdev->dev, moxart_rtc->gpio_sclk, | |
284 | GPIOF_DIR_OUT, "rtc_sclk"); | |
285 | if (ret) { | |
286 | dev_err(&pdev->dev, "can't get rtc_sclk gpio\n"); | |
287 | return ret; | |
288 | } | |
289 | ||
290 | ret = devm_gpio_request_one(&pdev->dev, moxart_rtc->gpio_reset, | |
291 | GPIOF_DIR_OUT, "rtc_reset"); | |
292 | if (ret) { | |
293 | dev_err(&pdev->dev, "can't get rtc_reset gpio\n"); | |
294 | return ret; | |
295 | } | |
296 | ||
297 | moxart_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, | |
298 | &moxart_rtc_ops, | |
299 | THIS_MODULE); | |
300 | if (IS_ERR(moxart_rtc->rtc)) { | |
301 | dev_err(&pdev->dev, "devm_rtc_device_register failed\n"); | |
302 | return PTR_ERR(moxart_rtc->rtc); | |
303 | } | |
304 | ||
305 | return 0; | |
306 | } | |
307 | ||
308 | static const struct of_device_id moxart_rtc_match[] = { | |
309 | { .compatible = "moxa,moxart-rtc" }, | |
310 | { }, | |
311 | }; | |
73798d5c | 312 | MODULE_DEVICE_TABLE(of, moxart_rtc_match); |
453b4c6d JJ |
313 | |
314 | static struct platform_driver moxart_rtc_driver = { | |
315 | .probe = moxart_rtc_probe, | |
316 | .driver = { | |
317 | .name = "moxart-rtc", | |
453b4c6d JJ |
318 | .of_match_table = moxart_rtc_match, |
319 | }, | |
320 | }; | |
321 | module_platform_driver(moxart_rtc_driver); | |
322 | ||
323 | MODULE_DESCRIPTION("MOXART RTC driver"); | |
324 | MODULE_LICENSE("GPL"); | |
325 | MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>"); |