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1/*
2 * An I2C driver for the Epson RX8581 RTC
3 *
4 * Author: Martyn Welch <martyn.welch@ge.com>
5 * Copyright 2008 GE Intelligent Platforms Embedded Systems, Inc.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * Based on: rtc-pcf8563.c (An I2C driver for the Philips PCF8563 RTC)
12 * Copyright 2005-06 Tower Technologies
13 */
14
15#include <linux/module.h>
16#include <linux/i2c.h>
17#include <linux/bcd.h>
18#include <linux/rtc.h>
19#include <linux/log2.h>
20
21#define DRV_VERSION "0.1"
22
23#define RX8581_REG_SC 0x00 /* Second in BCD */
24#define RX8581_REG_MN 0x01 /* Minute in BCD */
25#define RX8581_REG_HR 0x02 /* Hour in BCD */
26#define RX8581_REG_DW 0x03 /* Day of Week */
27#define RX8581_REG_DM 0x04 /* Day of Month in BCD */
28#define RX8581_REG_MO 0x05 /* Month in BCD */
29#define RX8581_REG_YR 0x06 /* Year in BCD */
30#define RX8581_REG_RAM 0x07 /* RAM */
31#define RX8581_REG_AMN 0x08 /* Alarm Min in BCD*/
32#define RX8581_REG_AHR 0x09 /* Alarm Hour in BCD */
33#define RX8581_REG_ADM 0x0A
34#define RX8581_REG_ADW 0x0A
35#define RX8581_REG_TMR0 0x0B
36#define RX8581_REG_TMR1 0x0C
37#define RX8581_REG_EXT 0x0D /* Extension Register */
38#define RX8581_REG_FLAG 0x0E /* Flag Register */
39#define RX8581_REG_CTRL 0x0F /* Control Register */
40
41
42/* Flag Register bit definitions */
43#define RX8581_FLAG_UF 0x20 /* Update */
44#define RX8581_FLAG_TF 0x10 /* Timer */
45#define RX8581_FLAG_AF 0x08 /* Alarm */
46#define RX8581_FLAG_VLF 0x02 /* Voltage Low */
47
48/* Control Register bit definitions */
49#define RX8581_CTRL_UIE 0x20 /* Update Interrupt Enable */
50#define RX8581_CTRL_TIE 0x10 /* Timer Interrupt Enable */
51#define RX8581_CTRL_AIE 0x08 /* Alarm Interrupt Enable */
52#define RX8581_CTRL_STOP 0x02 /* STOP bit */
53#define RX8581_CTRL_RESET 0x01 /* RESET bit */
54
55static struct i2c_driver rx8581_driver;
56
57/*
58 * In the routines that deal directly with the rx8581 hardware, we use
59 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
60 */
61static int rx8581_get_datetime(struct i2c_client *client, struct rtc_time *tm)
62{
63 unsigned char date[7];
64 int data, err;
65
66 /* First we ensure that the "update flag" is not set, we read the
67 * time and date then re-read the "update flag". If the update flag
68 * has been set, we know that the time has changed during the read so
69 * we repeat the whole process again.
70 */
71 data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
72 if (data < 0) {
73 dev_err(&client->dev, "Unable to read device flags\n");
74 return -EIO;
75 }
76
77 do {
78 /* If update flag set, clear it */
79 if (data & RX8581_FLAG_UF) {
80 err = i2c_smbus_write_byte_data(client,
81 RX8581_REG_FLAG, (data & ~RX8581_FLAG_UF));
82 if (err != 0) {
83 dev_err(&client->dev, "Unable to write device "
84 "flags\n");
85 return -EIO;
86 }
87 }
88
89 /* Now read time and date */
90 err = i2c_smbus_read_i2c_block_data(client, RX8581_REG_SC,
91 7, date);
92 if (err < 0) {
93 dev_err(&client->dev, "Unable to read date\n");
94 return -EIO;
95 }
96
97 /* Check flag register */
98 data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
99 if (data < 0) {
100 dev_err(&client->dev, "Unable to read device flags\n");
101 return -EIO;
102 }
103 } while (data & RX8581_FLAG_UF);
104
105 if (data & RX8581_FLAG_VLF)
106 dev_info(&client->dev,
107 "low voltage detected, date/time is not reliable.\n");
108
109 dev_dbg(&client->dev,
110 "%s: raw data is sec=%02x, min=%02x, hr=%02x, "
111 "wday=%02x, mday=%02x, mon=%02x, year=%02x\n",
112 __func__,
113 date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
114
115 tm->tm_sec = bcd2bin(date[RX8581_REG_SC] & 0x7F);
116 tm->tm_min = bcd2bin(date[RX8581_REG_MN] & 0x7F);
117 tm->tm_hour = bcd2bin(date[RX8581_REG_HR] & 0x3F); /* rtc hr 0-23 */
118 tm->tm_wday = ilog2(date[RX8581_REG_DW] & 0x7F);
119 tm->tm_mday = bcd2bin(date[RX8581_REG_DM] & 0x3F);
120 tm->tm_mon = bcd2bin(date[RX8581_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
121 tm->tm_year = bcd2bin(date[RX8581_REG_YR]);
122 if (tm->tm_year < 70)
123 tm->tm_year += 100; /* assume we are in 1970...2069 */
124
125
126 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
127 "mday=%d, mon=%d, year=%d, wday=%d\n",
128 __func__,
129 tm->tm_sec, tm->tm_min, tm->tm_hour,
130 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
131
132 err = rtc_valid_tm(tm);
133 if (err < 0)
134 dev_err(&client->dev, "retrieved date/time is not valid.\n");
135
136 return err;
137}
138
139static int rx8581_set_datetime(struct i2c_client *client, struct rtc_time *tm)
140{
141 int data, err;
142 unsigned char buf[7];
143
144 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
145 "mday=%d, mon=%d, year=%d, wday=%d\n",
146 __func__,
147 tm->tm_sec, tm->tm_min, tm->tm_hour,
148 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
149
150 /* hours, minutes and seconds */
151 buf[RX8581_REG_SC] = bin2bcd(tm->tm_sec);
152 buf[RX8581_REG_MN] = bin2bcd(tm->tm_min);
153 buf[RX8581_REG_HR] = bin2bcd(tm->tm_hour);
154
155 buf[RX8581_REG_DM] = bin2bcd(tm->tm_mday);
156
157 /* month, 1 - 12 */
158 buf[RX8581_REG_MO] = bin2bcd(tm->tm_mon + 1);
159
160 /* year and century */
161 buf[RX8581_REG_YR] = bin2bcd(tm->tm_year % 100);
162 buf[RX8581_REG_DW] = (0x1 << tm->tm_wday);
163
164 /* Stop the clock */
165 data = i2c_smbus_read_byte_data(client, RX8581_REG_CTRL);
166 if (data < 0) {
167 dev_err(&client->dev, "Unable to read control register\n");
168 return -EIO;
169 }
170
171 err = i2c_smbus_write_byte_data(client, RX8581_REG_CTRL,
172 (data | RX8581_CTRL_STOP));
173 if (err < 0) {
174 dev_err(&client->dev, "Unable to write control register\n");
175 return -EIO;
176 }
177
178 /* write register's data */
179 err = i2c_smbus_write_i2c_block_data(client, RX8581_REG_SC, 7, buf);
180 if (err < 0) {
181 dev_err(&client->dev, "Unable to write to date registers\n");
182 return -EIO;
183 }
184
185 /* get VLF and clear it */
186 data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
187 if (data < 0) {
188 dev_err(&client->dev, "Unable to read flag register\n");
189 return -EIO;
190 }
191
192 err = i2c_smbus_write_byte_data(client, RX8581_REG_FLAG,
193 (data & ~(RX8581_FLAG_VLF)));
194 if (err != 0) {
195 dev_err(&client->dev, "Unable to write flag register\n");
196 return -EIO;
197 }
198
199 /* Restart the clock */
200 data = i2c_smbus_read_byte_data(client, RX8581_REG_CTRL);
201 if (data < 0) {
202 dev_err(&client->dev, "Unable to read control register\n");
203 return -EIO;
204 }
205
206 err = i2c_smbus_write_byte_data(client, RX8581_REG_CTRL,
207 (data & ~(RX8581_CTRL_STOP)));
208 if (err != 0) {
209 dev_err(&client->dev, "Unable to write control register\n");
210 return -EIO;
211 }
212
213 return 0;
214}
215
216static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm)
217{
218 return rx8581_get_datetime(to_i2c_client(dev), tm);
219}
220
221static int rx8581_rtc_set_time(struct device *dev, struct rtc_time *tm)
222{
223 return rx8581_set_datetime(to_i2c_client(dev), tm);
224}
225
226static const struct rtc_class_ops rx8581_rtc_ops = {
227 .read_time = rx8581_rtc_read_time,
228 .set_time = rx8581_rtc_set_time,
229};
230
231static int __devinit rx8581_probe(struct i2c_client *client,
232 const struct i2c_device_id *id)
233{
234 struct rtc_device *rtc;
235
236 dev_dbg(&client->dev, "%s\n", __func__);
237
238 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
239 return -ENODEV;
240
241 dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
242
243 rtc = rtc_device_register(rx8581_driver.driver.name,
244 &client->dev, &rx8581_rtc_ops, THIS_MODULE);
245
246 if (IS_ERR(rtc))
247 return PTR_ERR(rtc);
248
249 i2c_set_clientdata(client, rtc);
250
251 return 0;
252}
253
254static int __devexit rx8581_remove(struct i2c_client *client)
255{
256 struct rtc_device *rtc = i2c_get_clientdata(client);
257
258 rtc_device_unregister(rtc);
259
260 return 0;
261}
262
263static const struct i2c_device_id rx8581_id[] = {
264 { "rx8581", 0 },
265 { }
266};
267MODULE_DEVICE_TABLE(i2c, rx8581_id);
268
269static struct i2c_driver rx8581_driver = {
270 .driver = {
271 .name = "rtc-rx8581",
272 .owner = THIS_MODULE,
273 },
274 .probe = rx8581_probe,
275 .remove = __devexit_p(rx8581_remove),
276 .id_table = rx8581_id,
277};
278
279module_i2c_driver(rx8581_driver);
280
281MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com>");
282MODULE_DESCRIPTION("Epson RX-8581 RTC driver");
283MODULE_LICENSE("GPL");
284MODULE_VERSION(DRV_VERSION);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * An I2C driver for the Epson RX8581 RTC
4 *
5 * Author: Martyn Welch <martyn.welch@ge.com>
6 * Copyright 2008 GE Intelligent Platforms Embedded Systems, Inc.
7 *
8 * Based on: rtc-pcf8563.c (An I2C driver for the Philips PCF8563 RTC)
9 * Copyright 2005-06 Tower Technologies
10 */
11
12#include <linux/module.h>
13#include <linux/i2c.h>
14#include <linux/bcd.h>
15#include <linux/of.h>
16#include <linux/of_device.h>
17#include <linux/regmap.h>
18#include <linux/rtc.h>
19#include <linux/log2.h>
20
21#define RX8581_REG_SC 0x00 /* Second in BCD */
22#define RX8581_REG_MN 0x01 /* Minute in BCD */
23#define RX8581_REG_HR 0x02 /* Hour in BCD */
24#define RX8581_REG_DW 0x03 /* Day of Week */
25#define RX8581_REG_DM 0x04 /* Day of Month in BCD */
26#define RX8581_REG_MO 0x05 /* Month in BCD */
27#define RX8581_REG_YR 0x06 /* Year in BCD */
28#define RX8581_REG_RAM 0x07 /* RAM */
29#define RX8581_REG_AMN 0x08 /* Alarm Min in BCD*/
30#define RX8581_REG_AHR 0x09 /* Alarm Hour in BCD */
31#define RX8581_REG_ADM 0x0A
32#define RX8581_REG_ADW 0x0A
33#define RX8581_REG_TMR0 0x0B
34#define RX8581_REG_TMR1 0x0C
35#define RX8581_REG_EXT 0x0D /* Extension Register */
36#define RX8581_REG_FLAG 0x0E /* Flag Register */
37#define RX8581_REG_CTRL 0x0F /* Control Register */
38
39
40/* Flag Register bit definitions */
41#define RX8581_FLAG_UF 0x20 /* Update */
42#define RX8581_FLAG_TF 0x10 /* Timer */
43#define RX8581_FLAG_AF 0x08 /* Alarm */
44#define RX8581_FLAG_VLF 0x02 /* Voltage Low */
45
46/* Control Register bit definitions */
47#define RX8581_CTRL_UIE 0x20 /* Update Interrupt Enable */
48#define RX8581_CTRL_TIE 0x10 /* Timer Interrupt Enable */
49#define RX8581_CTRL_AIE 0x08 /* Alarm Interrupt Enable */
50#define RX8581_CTRL_STOP 0x02 /* STOP bit */
51#define RX8581_CTRL_RESET 0x01 /* RESET bit */
52
53#define RX8571_USER_RAM 0x10
54#define RX8571_NVRAM_SIZE 0x10
55
56struct rx8581 {
57 struct regmap *regmap;
58 struct rtc_device *rtc;
59};
60
61struct rx85x1_config {
62 struct regmap_config regmap;
63 unsigned int num_nvram;
64};
65
66/*
67 * In the routines that deal directly with the rx8581 hardware, we use
68 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
69 */
70static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm)
71{
72 struct i2c_client *client = to_i2c_client(dev);
73 unsigned char date[7];
74 unsigned int data;
75 int err;
76 struct rx8581 *rx8581 = i2c_get_clientdata(client);
77
78 /* First we ensure that the "update flag" is not set, we read the
79 * time and date then re-read the "update flag". If the update flag
80 * has been set, we know that the time has changed during the read so
81 * we repeat the whole process again.
82 */
83 err = regmap_read(rx8581->regmap, RX8581_REG_FLAG, &data);
84 if (err < 0)
85 return err;
86
87 if (data & RX8581_FLAG_VLF) {
88 dev_warn(dev,
89 "low voltage detected, date/time is not reliable.\n");
90 return -EINVAL;
91 }
92
93 do {
94 /* If update flag set, clear it */
95 if (data & RX8581_FLAG_UF) {
96 err = regmap_write(rx8581->regmap, RX8581_REG_FLAG,
97 data & ~RX8581_FLAG_UF);
98 if (err < 0)
99 return err;
100 }
101
102 /* Now read time and date */
103 err = regmap_bulk_read(rx8581->regmap, RX8581_REG_SC, date,
104 sizeof(date));
105 if (err < 0)
106 return err;
107
108 /* Check flag register */
109 err = regmap_read(rx8581->regmap, RX8581_REG_FLAG, &data);
110 if (err < 0)
111 return err;
112 } while (data & RX8581_FLAG_UF);
113
114 dev_dbg(dev, "%s: raw data is sec=%02x, min=%02x, hr=%02x, "
115 "wday=%02x, mday=%02x, mon=%02x, year=%02x\n",
116 __func__,
117 date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
118
119 tm->tm_sec = bcd2bin(date[RX8581_REG_SC] & 0x7F);
120 tm->tm_min = bcd2bin(date[RX8581_REG_MN] & 0x7F);
121 tm->tm_hour = bcd2bin(date[RX8581_REG_HR] & 0x3F); /* rtc hr 0-23 */
122 tm->tm_wday = ilog2(date[RX8581_REG_DW] & 0x7F);
123 tm->tm_mday = bcd2bin(date[RX8581_REG_DM] & 0x3F);
124 tm->tm_mon = bcd2bin(date[RX8581_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
125 tm->tm_year = bcd2bin(date[RX8581_REG_YR]) + 100;
126
127 dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
128 "mday=%d, mon=%d, year=%d, wday=%d\n",
129 __func__,
130 tm->tm_sec, tm->tm_min, tm->tm_hour,
131 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
132
133 return 0;
134}
135
136static int rx8581_rtc_set_time(struct device *dev, struct rtc_time *tm)
137{
138 struct i2c_client *client = to_i2c_client(dev);
139 int err;
140 unsigned char buf[7];
141 struct rx8581 *rx8581 = i2c_get_clientdata(client);
142
143 dev_dbg(dev, "%s: secs=%d, mins=%d, hours=%d, "
144 "mday=%d, mon=%d, year=%d, wday=%d\n",
145 __func__,
146 tm->tm_sec, tm->tm_min, tm->tm_hour,
147 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
148
149 /* hours, minutes and seconds */
150 buf[RX8581_REG_SC] = bin2bcd(tm->tm_sec);
151 buf[RX8581_REG_MN] = bin2bcd(tm->tm_min);
152 buf[RX8581_REG_HR] = bin2bcd(tm->tm_hour);
153
154 buf[RX8581_REG_DM] = bin2bcd(tm->tm_mday);
155
156 /* month, 1 - 12 */
157 buf[RX8581_REG_MO] = bin2bcd(tm->tm_mon + 1);
158
159 /* year and century */
160 buf[RX8581_REG_YR] = bin2bcd(tm->tm_year - 100);
161 buf[RX8581_REG_DW] = (0x1 << tm->tm_wday);
162
163 /* Stop the clock */
164 err = regmap_update_bits(rx8581->regmap, RX8581_REG_CTRL,
165 RX8581_CTRL_STOP, RX8581_CTRL_STOP);
166 if (err < 0)
167 return err;
168
169 /* write register's data */
170 err = regmap_bulk_write(rx8581->regmap, RX8581_REG_SC,
171 buf, sizeof(buf));
172 if (err < 0)
173 return err;
174
175 /* get VLF and clear it */
176 err = regmap_update_bits(rx8581->regmap, RX8581_REG_FLAG,
177 RX8581_FLAG_VLF, 0);
178 if (err < 0)
179 return err;
180
181 /* Restart the clock */
182 return regmap_update_bits(rx8581->regmap, RX8581_REG_CTRL,
183 RX8581_CTRL_STOP, 0);
184}
185
186static const struct rtc_class_ops rx8581_rtc_ops = {
187 .read_time = rx8581_rtc_read_time,
188 .set_time = rx8581_rtc_set_time,
189};
190
191static int rx8571_nvram_read(void *priv, unsigned int offset, void *val,
192 size_t bytes)
193{
194 struct rx8581 *rx8581 = priv;
195
196 return regmap_bulk_read(rx8581->regmap, RX8571_USER_RAM + offset,
197 val, bytes);
198}
199
200static int rx8571_nvram_write(void *priv, unsigned int offset, void *val,
201 size_t bytes)
202{
203 struct rx8581 *rx8581 = priv;
204
205 return regmap_bulk_write(rx8581->regmap, RX8571_USER_RAM + offset,
206 val, bytes);
207}
208
209static int rx85x1_nvram_read(void *priv, unsigned int offset, void *val,
210 size_t bytes)
211{
212 struct rx8581 *rx8581 = priv;
213 unsigned int tmp_val;
214 int ret;
215
216 ret = regmap_read(rx8581->regmap, RX8581_REG_RAM, &tmp_val);
217 (*(unsigned char *)val) = (unsigned char) tmp_val;
218
219 return ret;
220}
221
222static int rx85x1_nvram_write(void *priv, unsigned int offset, void *val,
223 size_t bytes)
224{
225 struct rx8581 *rx8581 = priv;
226 unsigned char tmp_val;
227
228 tmp_val = *((unsigned char *)val);
229 return regmap_write(rx8581->regmap, RX8581_REG_RAM,
230 (unsigned int)tmp_val);
231}
232
233static const struct rx85x1_config rx8581_config = {
234 .regmap = {
235 .reg_bits = 8,
236 .val_bits = 8,
237 .max_register = 0xf,
238 },
239 .num_nvram = 1
240};
241
242static const struct rx85x1_config rx8571_config = {
243 .regmap = {
244 .reg_bits = 8,
245 .val_bits = 8,
246 .max_register = 0x1f,
247 },
248 .num_nvram = 2
249};
250
251static int rx8581_probe(struct i2c_client *client)
252{
253 struct rx8581 *rx8581;
254 const struct rx85x1_config *config = &rx8581_config;
255 const void *data = of_device_get_match_data(&client->dev);
256 static struct nvmem_config nvmem_cfg[] = {
257 {
258 .name = "rx85x1-",
259 .word_size = 1,
260 .stride = 1,
261 .size = 1,
262 .reg_read = rx85x1_nvram_read,
263 .reg_write = rx85x1_nvram_write,
264 }, {
265 .name = "rx8571-",
266 .word_size = 1,
267 .stride = 1,
268 .size = RX8571_NVRAM_SIZE,
269 .reg_read = rx8571_nvram_read,
270 .reg_write = rx8571_nvram_write,
271 },
272 };
273 int ret, i;
274
275 dev_dbg(&client->dev, "%s\n", __func__);
276
277 if (data)
278 config = data;
279
280 rx8581 = devm_kzalloc(&client->dev, sizeof(struct rx8581), GFP_KERNEL);
281 if (!rx8581)
282 return -ENOMEM;
283
284 i2c_set_clientdata(client, rx8581);
285
286 rx8581->regmap = devm_regmap_init_i2c(client, &config->regmap);
287 if (IS_ERR(rx8581->regmap))
288 return PTR_ERR(rx8581->regmap);
289
290 rx8581->rtc = devm_rtc_allocate_device(&client->dev);
291 if (IS_ERR(rx8581->rtc))
292 return PTR_ERR(rx8581->rtc);
293
294 rx8581->rtc->ops = &rx8581_rtc_ops;
295 rx8581->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
296 rx8581->rtc->range_max = RTC_TIMESTAMP_END_2099;
297 rx8581->rtc->start_secs = 0;
298 rx8581->rtc->set_start_time = true;
299
300 ret = devm_rtc_register_device(rx8581->rtc);
301
302 for (i = 0; i < config->num_nvram; i++) {
303 nvmem_cfg[i].priv = rx8581;
304 devm_rtc_nvmem_register(rx8581->rtc, &nvmem_cfg[i]);
305 }
306
307 return ret;
308}
309
310static const struct i2c_device_id rx8581_id[] = {
311 { "rx8581", 0 },
312 { }
313};
314MODULE_DEVICE_TABLE(i2c, rx8581_id);
315
316static const __maybe_unused struct of_device_id rx8581_of_match[] = {
317 { .compatible = "epson,rx8571", .data = &rx8571_config },
318 { .compatible = "epson,rx8581", .data = &rx8581_config },
319 { /* sentinel */ }
320};
321MODULE_DEVICE_TABLE(of, rx8581_of_match);
322
323static struct i2c_driver rx8581_driver = {
324 .driver = {
325 .name = "rtc-rx8581",
326 .of_match_table = of_match_ptr(rx8581_of_match),
327 },
328 .probe_new = rx8581_probe,
329 .id_table = rx8581_id,
330};
331
332module_i2c_driver(rx8581_driver);
333
334MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com>");
335MODULE_DESCRIPTION("Epson RX-8571/RX-8581 RTC driver");
336MODULE_LICENSE("GPL");