Roman Fietze | d6c7428 | 2010-08-10 18:02:14 -0700 | [diff] [blame] | 1 | /* |
| 2 | * An I2C driver for the Intersil ISL 12022 |
| 3 | * |
| 4 | * Author: Roman Fietze <roman.fietze@telemotive.de> |
| 5 | * |
| 6 | * Based on the Philips PCF8563 RTC |
| 7 | * by Alessandro Zummo <a.zummo@towertech.it>. |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or |
| 10 | * modify it under the terms of the GNU General Public License version |
| 11 | * 2 as published by the Free Software Foundation. |
| 12 | */ |
| 13 | |
| 14 | #include <linux/i2c.h> |
| 15 | #include <linux/bcd.h> |
| 16 | #include <linux/rtc.h> |
| 17 | #include <linux/slab.h> |
Paul Gortmaker | 2113852 | 2011-05-27 09:57:25 -0400 | [diff] [blame] | 18 | #include <linux/module.h> |
Sachin Kamat | 17cc54b2 | 2013-07-03 15:07:49 -0700 | [diff] [blame] | 19 | #include <linux/err.h> |
Stuart Longland | db04d62 | 2014-08-08 14:20:20 -0700 | [diff] [blame^] | 20 | #include <linux/of.h> |
| 21 | #include <linux/of_device.h> |
Roman Fietze | d6c7428 | 2010-08-10 18:02:14 -0700 | [diff] [blame] | 22 | |
| 23 | #define DRV_VERSION "0.1" |
| 24 | |
| 25 | /* ISL register offsets */ |
| 26 | #define ISL12022_REG_SC 0x00 |
| 27 | #define ISL12022_REG_MN 0x01 |
| 28 | #define ISL12022_REG_HR 0x02 |
| 29 | #define ISL12022_REG_DT 0x03 |
| 30 | #define ISL12022_REG_MO 0x04 |
| 31 | #define ISL12022_REG_YR 0x05 |
| 32 | #define ISL12022_REG_DW 0x06 |
| 33 | |
| 34 | #define ISL12022_REG_SR 0x07 |
| 35 | #define ISL12022_REG_INT 0x08 |
| 36 | |
| 37 | /* ISL register bits */ |
| 38 | #define ISL12022_HR_MIL (1 << 7) /* military or 24 hour time */ |
| 39 | |
| 40 | #define ISL12022_SR_LBAT85 (1 << 2) |
| 41 | #define ISL12022_SR_LBAT75 (1 << 1) |
| 42 | |
| 43 | #define ISL12022_INT_WRTC (1 << 6) |
| 44 | |
| 45 | |
| 46 | static struct i2c_driver isl12022_driver; |
| 47 | |
| 48 | struct isl12022 { |
| 49 | struct rtc_device *rtc; |
| 50 | |
| 51 | bool write_enabled; /* true if write enable is set */ |
| 52 | }; |
| 53 | |
| 54 | |
| 55 | static int isl12022_read_regs(struct i2c_client *client, uint8_t reg, |
| 56 | uint8_t *data, size_t n) |
| 57 | { |
| 58 | struct i2c_msg msgs[] = { |
| 59 | { |
| 60 | .addr = client->addr, |
| 61 | .flags = 0, |
| 62 | .len = 1, |
| 63 | .buf = data |
| 64 | }, /* setup read ptr */ |
| 65 | { |
| 66 | .addr = client->addr, |
| 67 | .flags = I2C_M_RD, |
| 68 | .len = n, |
| 69 | .buf = data |
| 70 | } |
| 71 | }; |
| 72 | |
| 73 | int ret; |
| 74 | |
| 75 | data[0] = reg; |
| 76 | ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); |
| 77 | if (ret != ARRAY_SIZE(msgs)) { |
| 78 | dev_err(&client->dev, "%s: read error, ret=%d\n", |
| 79 | __func__, ret); |
| 80 | return -EIO; |
| 81 | } |
| 82 | |
| 83 | return 0; |
| 84 | } |
| 85 | |
| 86 | |
| 87 | static int isl12022_write_reg(struct i2c_client *client, |
| 88 | uint8_t reg, uint8_t val) |
| 89 | { |
| 90 | uint8_t data[2] = { reg, val }; |
| 91 | int err; |
| 92 | |
| 93 | err = i2c_master_send(client, data, sizeof(data)); |
| 94 | if (err != sizeof(data)) { |
| 95 | dev_err(&client->dev, |
| 96 | "%s: err=%d addr=%02x, data=%02x\n", |
| 97 | __func__, err, data[0], data[1]); |
| 98 | return -EIO; |
| 99 | } |
| 100 | |
| 101 | return 0; |
| 102 | } |
| 103 | |
| 104 | |
| 105 | /* |
| 106 | * In the routines that deal directly with the isl12022 hardware, we use |
| 107 | * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. |
| 108 | */ |
| 109 | static int isl12022_get_datetime(struct i2c_client *client, struct rtc_time *tm) |
| 110 | { |
| 111 | uint8_t buf[ISL12022_REG_INT + 1]; |
| 112 | int ret; |
| 113 | |
| 114 | ret = isl12022_read_regs(client, ISL12022_REG_SC, buf, sizeof(buf)); |
| 115 | if (ret) |
| 116 | return ret; |
| 117 | |
| 118 | if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 | ISL12022_SR_LBAT75)) { |
| 119 | dev_warn(&client->dev, |
| 120 | "voltage dropped below %u%%, " |
| 121 | "date and time is not reliable.\n", |
| 122 | buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75); |
| 123 | } |
| 124 | |
| 125 | dev_dbg(&client->dev, |
| 126 | "%s: raw data is sec=%02x, min=%02x, hr=%02x, " |
| 127 | "mday=%02x, mon=%02x, year=%02x, wday=%02x, " |
| 128 | "sr=%02x, int=%02x", |
| 129 | __func__, |
| 130 | buf[ISL12022_REG_SC], |
| 131 | buf[ISL12022_REG_MN], |
| 132 | buf[ISL12022_REG_HR], |
| 133 | buf[ISL12022_REG_DT], |
| 134 | buf[ISL12022_REG_MO], |
| 135 | buf[ISL12022_REG_YR], |
| 136 | buf[ISL12022_REG_DW], |
| 137 | buf[ISL12022_REG_SR], |
| 138 | buf[ISL12022_REG_INT]); |
| 139 | |
| 140 | tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F); |
| 141 | tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F); |
| 142 | tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F); |
| 143 | tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F); |
| 144 | tm->tm_wday = buf[ISL12022_REG_DW] & 0x07; |
| 145 | tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1; |
| 146 | tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100; |
| 147 | |
| 148 | dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, " |
| 149 | "mday=%d, mon=%d, year=%d, wday=%d\n", |
| 150 | __func__, |
| 151 | tm->tm_sec, tm->tm_min, tm->tm_hour, |
| 152 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); |
| 153 | |
| 154 | /* The clock can give out invalid datetime, but we cannot return |
| 155 | * -EINVAL otherwise hwclock will refuse to set the time on bootup. */ |
| 156 | if (rtc_valid_tm(tm) < 0) |
| 157 | dev_err(&client->dev, "retrieved date and time is invalid.\n"); |
| 158 | |
| 159 | return 0; |
| 160 | } |
| 161 | |
| 162 | static int isl12022_set_datetime(struct i2c_client *client, struct rtc_time *tm) |
| 163 | { |
| 164 | struct isl12022 *isl12022 = i2c_get_clientdata(client); |
| 165 | size_t i; |
| 166 | int ret; |
| 167 | uint8_t buf[ISL12022_REG_DW + 1]; |
| 168 | |
| 169 | dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, " |
| 170 | "mday=%d, mon=%d, year=%d, wday=%d\n", |
| 171 | __func__, |
| 172 | tm->tm_sec, tm->tm_min, tm->tm_hour, |
| 173 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); |
| 174 | |
| 175 | if (!isl12022->write_enabled) { |
| 176 | |
| 177 | ret = isl12022_read_regs(client, ISL12022_REG_INT, buf, 1); |
| 178 | if (ret) |
| 179 | return ret; |
| 180 | |
| 181 | /* Check if WRTC (write rtc enable) is set factory default is |
| 182 | * 0 (not set) */ |
| 183 | if (!(buf[0] & ISL12022_INT_WRTC)) { |
| 184 | dev_info(&client->dev, |
| 185 | "init write enable and 24 hour format\n"); |
| 186 | |
| 187 | /* Set the write enable bit. */ |
| 188 | ret = isl12022_write_reg(client, |
| 189 | ISL12022_REG_INT, |
| 190 | buf[0] | ISL12022_INT_WRTC); |
| 191 | if (ret) |
| 192 | return ret; |
| 193 | |
| 194 | /* Write to any RTC register to start RTC, we use the |
| 195 | * HR register, setting the MIL bit to use the 24 hour |
| 196 | * format. */ |
| 197 | ret = isl12022_read_regs(client, ISL12022_REG_HR, |
| 198 | buf, 1); |
| 199 | if (ret) |
| 200 | return ret; |
| 201 | |
| 202 | ret = isl12022_write_reg(client, |
| 203 | ISL12022_REG_HR, |
| 204 | buf[0] | ISL12022_HR_MIL); |
| 205 | if (ret) |
| 206 | return ret; |
| 207 | } |
| 208 | |
| 209 | isl12022->write_enabled = 1; |
| 210 | } |
| 211 | |
| 212 | /* hours, minutes and seconds */ |
| 213 | buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec); |
| 214 | buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min); |
Roman Fietze | 6d23b25 | 2010-08-10 18:02:21 -0700 | [diff] [blame] | 215 | buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) | ISL12022_HR_MIL; |
Roman Fietze | d6c7428 | 2010-08-10 18:02:14 -0700 | [diff] [blame] | 216 | |
| 217 | buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday); |
| 218 | |
| 219 | /* month, 1 - 12 */ |
| 220 | buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1); |
| 221 | |
| 222 | /* year and century */ |
| 223 | buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100); |
| 224 | |
| 225 | buf[ISL12022_REG_DW] = tm->tm_wday & 0x07; |
| 226 | |
| 227 | /* write register's data */ |
| 228 | for (i = 0; i < ARRAY_SIZE(buf); i++) { |
| 229 | ret = isl12022_write_reg(client, ISL12022_REG_SC + i, |
| 230 | buf[ISL12022_REG_SC + i]); |
| 231 | if (ret) |
| 232 | return -EIO; |
Peter Senna Tschudin | 0b7e039 | 2013-02-21 16:44:30 -0800 | [diff] [blame] | 233 | } |
Roman Fietze | d6c7428 | 2010-08-10 18:02:14 -0700 | [diff] [blame] | 234 | |
| 235 | return 0; |
| 236 | } |
| 237 | |
| 238 | static int isl12022_rtc_read_time(struct device *dev, struct rtc_time *tm) |
| 239 | { |
| 240 | return isl12022_get_datetime(to_i2c_client(dev), tm); |
| 241 | } |
| 242 | |
| 243 | static int isl12022_rtc_set_time(struct device *dev, struct rtc_time *tm) |
| 244 | { |
| 245 | return isl12022_set_datetime(to_i2c_client(dev), tm); |
| 246 | } |
| 247 | |
| 248 | static const struct rtc_class_ops isl12022_rtc_ops = { |
| 249 | .read_time = isl12022_rtc_read_time, |
| 250 | .set_time = isl12022_rtc_set_time, |
| 251 | }; |
| 252 | |
| 253 | static int isl12022_probe(struct i2c_client *client, |
| 254 | const struct i2c_device_id *id) |
| 255 | { |
| 256 | struct isl12022 *isl12022; |
| 257 | |
Roman Fietze | d6c7428 | 2010-08-10 18:02:14 -0700 | [diff] [blame] | 258 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) |
| 259 | return -ENODEV; |
| 260 | |
Jingoo Han | dc831f9 | 2013-04-29 16:20:41 -0700 | [diff] [blame] | 261 | isl12022 = devm_kzalloc(&client->dev, sizeof(struct isl12022), |
| 262 | GFP_KERNEL); |
Roman Fietze | d6c7428 | 2010-08-10 18:02:14 -0700 | [diff] [blame] | 263 | if (!isl12022) |
| 264 | return -ENOMEM; |
| 265 | |
| 266 | dev_dbg(&client->dev, "chip found, driver version " DRV_VERSION "\n"); |
| 267 | |
| 268 | i2c_set_clientdata(client, isl12022); |
| 269 | |
Jingoo Han | dc831f9 | 2013-04-29 16:20:41 -0700 | [diff] [blame] | 270 | isl12022->rtc = devm_rtc_device_register(&client->dev, |
| 271 | isl12022_driver.driver.name, |
| 272 | &isl12022_rtc_ops, THIS_MODULE); |
Sachin Kamat | dac30a9 | 2013-07-15 15:43:32 +0530 | [diff] [blame] | 273 | return PTR_ERR_OR_ZERO(isl12022->rtc); |
Roman Fietze | d6c7428 | 2010-08-10 18:02:14 -0700 | [diff] [blame] | 274 | } |
| 275 | |
Stuart Longland | db04d62 | 2014-08-08 14:20:20 -0700 | [diff] [blame^] | 276 | #ifdef CONFIG_OF |
| 277 | static struct of_device_id isl12022_dt_match[] = { |
| 278 | { .compatible = "isl,isl12022" }, |
| 279 | { }, |
| 280 | }; |
| 281 | #endif |
| 282 | |
Roman Fietze | d6c7428 | 2010-08-10 18:02:14 -0700 | [diff] [blame] | 283 | static const struct i2c_device_id isl12022_id[] = { |
| 284 | { "isl12022", 0 }, |
Roman Fietze | d6c7428 | 2010-08-10 18:02:14 -0700 | [diff] [blame] | 285 | { } |
| 286 | }; |
| 287 | MODULE_DEVICE_TABLE(i2c, isl12022_id); |
| 288 | |
| 289 | static struct i2c_driver isl12022_driver = { |
| 290 | .driver = { |
| 291 | .name = "rtc-isl12022", |
Stuart Longland | db04d62 | 2014-08-08 14:20:20 -0700 | [diff] [blame^] | 292 | #ifdef CONFIG_OF |
| 293 | .of_match_table = of_match_ptr(isl12022_dt_match), |
| 294 | #endif |
Roman Fietze | d6c7428 | 2010-08-10 18:02:14 -0700 | [diff] [blame] | 295 | }, |
| 296 | .probe = isl12022_probe, |
Roman Fietze | d6c7428 | 2010-08-10 18:02:14 -0700 | [diff] [blame] | 297 | .id_table = isl12022_id, |
| 298 | }; |
| 299 | |
Axel Lin | 0abc920 | 2012-03-23 15:02:31 -0700 | [diff] [blame] | 300 | module_i2c_driver(isl12022_driver); |
Roman Fietze | d6c7428 | 2010-08-10 18:02:14 -0700 | [diff] [blame] | 301 | |
| 302 | MODULE_AUTHOR("roman.fietze@telemotive.de"); |
| 303 | MODULE_DESCRIPTION("ISL 12022 RTC driver"); |
| 304 | MODULE_LICENSE("GPL"); |
| 305 | MODULE_VERSION(DRV_VERSION); |