Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 1 | /* |
| 2 | * An rtc/i2c driver for the Dallas DS1672 |
Alessandro Zummo | 3903586 | 2006-04-10 22:54:41 -0700 | [diff] [blame] | 3 | * Copyright 2005-06 Tower Technologies |
| 4 | * |
| 5 | * Author: Alessandro Zummo <a.zummo@towertech.it> |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 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 | |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 12 | #include <linux/i2c.h> |
| 13 | #include <linux/rtc.h> |
Paul Gortmaker | 2113852 | 2011-05-27 09:57:25 -0400 | [diff] [blame] | 14 | #include <linux/module.h> |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 15 | |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 16 | #define DRV_VERSION "0.4" |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 17 | |
| 18 | /* Registers */ |
| 19 | |
| 20 | #define DS1672_REG_CNT_BASE 0 |
| 21 | #define DS1672_REG_CONTROL 4 |
| 22 | #define DS1672_REG_TRICKLE 5 |
| 23 | |
Alessandro Zummo | 3903586 | 2006-04-10 22:54:41 -0700 | [diff] [blame] | 24 | #define DS1672_REG_CONTROL_EOSC 0x80 |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 25 | |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 26 | static struct i2c_driver ds1672_driver; |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 27 | |
| 28 | /* |
| 29 | * In the routines that deal directly with the ds1672 hardware, we use |
| 30 | * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch |
| 31 | * Epoch is initialized as 2000. Time is set to UTC. |
| 32 | */ |
| 33 | static int ds1672_get_datetime(struct i2c_client *client, struct rtc_time *tm) |
| 34 | { |
| 35 | unsigned long time; |
| 36 | unsigned char addr = DS1672_REG_CNT_BASE; |
| 37 | unsigned char buf[4]; |
| 38 | |
| 39 | struct i2c_msg msgs[] = { |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 40 | {client->addr, 0, 1, &addr}, /* setup read ptr */ |
| 41 | {client->addr, I2C_M_RD, 4, buf}, /* read date */ |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 42 | }; |
| 43 | |
| 44 | /* read date registers */ |
| 45 | if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { |
Harvey Harrison | 2a4e2b8 | 2008-04-28 02:12:00 -0700 | [diff] [blame] | 46 | dev_err(&client->dev, "%s: read error\n", __func__); |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 47 | return -EIO; |
| 48 | } |
| 49 | |
| 50 | dev_dbg(&client->dev, |
Jeff Garzik | 11966ad | 2006-10-04 04:41:53 -0400 | [diff] [blame] | 51 | "%s: raw read data - counters=%02x,%02x,%02x,%02x\n", |
Harvey Harrison | 2a4e2b8 | 2008-04-28 02:12:00 -0700 | [diff] [blame] | 52 | __func__, buf[0], buf[1], buf[2], buf[3]); |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 53 | |
| 54 | time = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; |
| 55 | |
| 56 | rtc_time_to_tm(time, tm); |
| 57 | |
| 58 | dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " |
| 59 | "mday=%d, mon=%d, year=%d, wday=%d\n", |
Harvey Harrison | 2a4e2b8 | 2008-04-28 02:12:00 -0700 | [diff] [blame] | 60 | __func__, tm->tm_sec, tm->tm_min, tm->tm_hour, |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 61 | tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); |
| 62 | |
| 63 | return 0; |
| 64 | } |
| 65 | |
| 66 | static int ds1672_set_mmss(struct i2c_client *client, unsigned long secs) |
| 67 | { |
| 68 | int xfer; |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame] | 69 | unsigned char buf[6]; |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 70 | |
| 71 | buf[0] = DS1672_REG_CNT_BASE; |
| 72 | buf[1] = secs & 0x000000FF; |
| 73 | buf[2] = (secs & 0x0000FF00) >> 8; |
| 74 | buf[3] = (secs & 0x00FF0000) >> 16; |
| 75 | buf[4] = (secs & 0xFF000000) >> 24; |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 76 | buf[5] = 0; /* set control reg to enable counting */ |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 77 | |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame] | 78 | xfer = i2c_master_send(client, buf, 6); |
| 79 | if (xfer != 6) { |
Harvey Harrison | 2a4e2b8 | 2008-04-28 02:12:00 -0700 | [diff] [blame] | 80 | dev_err(&client->dev, "%s: send: %d\n", __func__, xfer); |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 81 | return -EIO; |
| 82 | } |
| 83 | |
| 84 | return 0; |
| 85 | } |
| 86 | |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 87 | static int ds1672_rtc_read_time(struct device *dev, struct rtc_time *tm) |
| 88 | { |
| 89 | return ds1672_get_datetime(to_i2c_client(dev), tm); |
| 90 | } |
| 91 | |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 92 | static int ds1672_rtc_set_mmss(struct device *dev, unsigned long secs) |
| 93 | { |
| 94 | return ds1672_set_mmss(to_i2c_client(dev), secs); |
| 95 | } |
| 96 | |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame] | 97 | static int ds1672_get_control(struct i2c_client *client, u8 *status) |
| 98 | { |
| 99 | unsigned char addr = DS1672_REG_CONTROL; |
| 100 | |
| 101 | struct i2c_msg msgs[] = { |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 102 | {client->addr, 0, 1, &addr}, /* setup read ptr */ |
| 103 | {client->addr, I2C_M_RD, 1, status}, /* read control */ |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame] | 104 | }; |
| 105 | |
| 106 | /* read control register */ |
| 107 | if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { |
Harvey Harrison | 2a4e2b8 | 2008-04-28 02:12:00 -0700 | [diff] [blame] | 108 | dev_err(&client->dev, "%s: read error\n", __func__); |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame] | 109 | return -EIO; |
| 110 | } |
| 111 | |
| 112 | return 0; |
| 113 | } |
| 114 | |
| 115 | /* following are the sysfs callback functions */ |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 116 | static ssize_t show_control(struct device *dev, struct device_attribute *attr, |
| 117 | char *buf) |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame] | 118 | { |
| 119 | struct i2c_client *client = to_i2c_client(dev); |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame] | 120 | u8 control; |
| 121 | int err; |
| 122 | |
| 123 | err = ds1672_get_control(client, &control); |
| 124 | if (err) |
| 125 | return err; |
| 126 | |
Alessandro Zummo | 3903586 | 2006-04-10 22:54:41 -0700 | [diff] [blame] | 127 | return sprintf(buf, "%s\n", (control & DS1672_REG_CONTROL_EOSC) |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 128 | ? "disabled" : "enabled"); |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame] | 129 | } |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 130 | |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame] | 131 | static DEVICE_ATTR(control, S_IRUGO, show_control, NULL); |
| 132 | |
David Brownell | ff8371a | 2006-09-30 23:28:17 -0700 | [diff] [blame] | 133 | static const struct rtc_class_ops ds1672_rtc_ops = { |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 134 | .read_time = ds1672_rtc_read_time, |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 135 | .set_mmss = ds1672_rtc_set_mmss, |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 136 | }; |
| 137 | |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 138 | static int ds1672_remove(struct i2c_client *client) |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 139 | { |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 140 | struct rtc_device *rtc = i2c_get_clientdata(client); |
| 141 | |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 142 | if (rtc) |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 143 | rtc_device_unregister(rtc); |
| 144 | |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 145 | return 0; |
| 146 | } |
| 147 | |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 148 | static int ds1672_probe(struct i2c_client *client, |
| 149 | const struct i2c_device_id *id) |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 150 | { |
| 151 | int err = 0; |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame] | 152 | u8 control; |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 153 | struct rtc_device *rtc; |
| 154 | |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 155 | dev_dbg(&client->dev, "%s\n", __func__); |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 156 | |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 157 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) |
| 158 | return -ENODEV; |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 159 | |
| 160 | dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); |
| 161 | |
| 162 | rtc = rtc_device_register(ds1672_driver.driver.name, &client->dev, |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 163 | &ds1672_rtc_ops, THIS_MODULE); |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 164 | |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 165 | if (IS_ERR(rtc)) |
| 166 | return PTR_ERR(rtc); |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 167 | |
| 168 | i2c_set_clientdata(client, rtc); |
| 169 | |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame] | 170 | /* read control register */ |
| 171 | err = ds1672_get_control(client, &control); |
Alessandro Zummo | 3903586 | 2006-04-10 22:54:41 -0700 | [diff] [blame] | 172 | if (err) |
Jeff Garzik | 91046a8 | 2006-12-06 20:35:34 -0800 | [diff] [blame] | 173 | goto exit_devreg; |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame] | 174 | |
| 175 | if (control & DS1672_REG_CONTROL_EOSC) |
| 176 | dev_warn(&client->dev, "Oscillator not enabled. " |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 177 | "Set time to enable.\n"); |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame] | 178 | |
| 179 | /* Register sysfs hooks */ |
Jeff Garzik | 91046a8 | 2006-12-06 20:35:34 -0800 | [diff] [blame] | 180 | err = device_create_file(&client->dev, &dev_attr_control); |
| 181 | if (err) |
| 182 | goto exit_devreg; |
Kumar Gala | 8a95b25 | 2006-04-10 22:54:39 -0700 | [diff] [blame] | 183 | |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 184 | return 0; |
| 185 | |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 186 | exit_devreg: |
Jeff Garzik | 91046a8 | 2006-12-06 20:35:34 -0800 | [diff] [blame] | 187 | rtc_device_unregister(rtc); |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 188 | return err; |
| 189 | } |
| 190 | |
Alessandro Zummo | fe102c7 | 2008-12-09 13:14:11 -0800 | [diff] [blame] | 191 | static struct i2c_device_id ds1672_id[] = { |
| 192 | { "ds1672", 0 }, |
| 193 | { } |
| 194 | }; |
| 195 | |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 196 | static struct i2c_driver ds1672_driver = { |
| 197 | .driver = { |
| 198 | .name = "rtc-ds1672", |
| 199 | }, |
| 200 | .probe = &ds1672_probe, |
| 201 | .remove = &ds1672_remove, |
Alessandro Zummo | fe102c7 | 2008-12-09 13:14:11 -0800 | [diff] [blame] | 202 | .id_table = ds1672_id, |
Alessandro Zummo | 1716b0f | 2008-10-15 22:03:10 -0700 | [diff] [blame] | 203 | }; |
| 204 | |
Axel Lin | 0abc920 | 2012-03-23 15:02:31 -0700 | [diff] [blame^] | 205 | module_i2c_driver(ds1672_driver); |
Alessandro Zummo | edf1aaa | 2006-03-27 01:16:43 -0800 | [diff] [blame] | 206 | |
| 207 | MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); |
| 208 | MODULE_DESCRIPTION("Dallas/Maxim DS1672 timekeeper driver"); |
| 209 | MODULE_LICENSE("GPL"); |
| 210 | MODULE_VERSION(DRV_VERSION); |