| /* |
| * linux/drivers/i2c/chips/ds1337.c |
| * |
| * Copyright (C) 2005 James Chapman <jchapman@katalix.com> |
| * |
| * based on linux/drivers/acorn/char/pcf8583.c |
| * Copyright (C) 2000 Russell King |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * Driver for Dallas Semiconductor DS1337 and DS1339 real time clock chip |
| */ |
| |
| #include <linux/config.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/slab.h> |
| #include <linux/i2c.h> |
| #include <linux/i2c-sensor.h> |
| #include <linux/string.h> |
| #include <linux/rtc.h> /* get the user-level API */ |
| #include <linux/bcd.h> |
| #include <linux/list.h> |
| |
| /* Device registers */ |
| #define DS1337_REG_HOUR 2 |
| #define DS1337_REG_DAY 3 |
| #define DS1337_REG_DATE 4 |
| #define DS1337_REG_MONTH 5 |
| #define DS1337_REG_CONTROL 14 |
| #define DS1337_REG_STATUS 15 |
| |
| /* FIXME - how do we export these interface constants? */ |
| #define DS1337_GET_DATE 0 |
| #define DS1337_SET_DATE 1 |
| |
| /* |
| * Functions declaration |
| */ |
| static unsigned short normal_i2c[] = { 0x68, I2C_CLIENT_END }; |
| static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END }; |
| |
| SENSORS_INSMOD_1(ds1337); |
| |
| static int ds1337_attach_adapter(struct i2c_adapter *adapter); |
| static int ds1337_detect(struct i2c_adapter *adapter, int address, int kind); |
| static void ds1337_init_client(struct i2c_client *client); |
| static int ds1337_detach_client(struct i2c_client *client); |
| static int ds1337_command(struct i2c_client *client, unsigned int cmd, |
| void *arg); |
| |
| /* |
| * Driver data (common to all clients) |
| */ |
| static struct i2c_driver ds1337_driver = { |
| .owner = THIS_MODULE, |
| .name = "ds1337", |
| .flags = I2C_DF_NOTIFY, |
| .attach_adapter = ds1337_attach_adapter, |
| .detach_client = ds1337_detach_client, |
| .command = ds1337_command, |
| }; |
| |
| /* |
| * Client data (each client gets its own) |
| */ |
| struct ds1337_data { |
| struct i2c_client client; |
| struct list_head list; |
| }; |
| |
| /* |
| * Internal variables |
| */ |
| static LIST_HEAD(ds1337_clients); |
| |
| static inline int ds1337_read(struct i2c_client *client, u8 reg, u8 *value) |
| { |
| s32 tmp = i2c_smbus_read_byte_data(client, reg); |
| |
| if (tmp < 0) |
| return -EIO; |
| |
| *value = tmp; |
| |
| return 0; |
| } |
| |
| /* |
| * Chip access functions |
| */ |
| static int ds1337_get_datetime(struct i2c_client *client, struct rtc_time *dt) |
| { |
| int result; |
| u8 buf[7]; |
| u8 val; |
| struct i2c_msg msg[2]; |
| u8 offs = 0; |
| |
| if (!dt) { |
| dev_dbg(&client->dev, "%s: EINVAL: dt=NULL\n", __FUNCTION__); |
| return -EINVAL; |
| } |
| |
| msg[0].addr = client->addr; |
| msg[0].flags = 0; |
| msg[0].len = 1; |
| msg[0].buf = &offs; |
| |
| msg[1].addr = client->addr; |
| msg[1].flags = I2C_M_RD; |
| msg[1].len = sizeof(buf); |
| msg[1].buf = &buf[0]; |
| |
| result = i2c_transfer(client->adapter, msg, 2); |
| |
| dev_dbg(&client->dev, "%s: [%d] %02x %02x %02x %02x %02x %02x %02x\n", |
| __FUNCTION__, result, buf[0], buf[1], buf[2], buf[3], |
| buf[4], buf[5], buf[6]); |
| |
| if (result == 2) { |
| dt->tm_sec = BCD2BIN(buf[0]); |
| dt->tm_min = BCD2BIN(buf[1]); |
| val = buf[2] & 0x3f; |
| dt->tm_hour = BCD2BIN(val); |
| dt->tm_wday = BCD2BIN(buf[3]) - 1; |
| dt->tm_mday = BCD2BIN(buf[4]); |
| val = buf[5] & 0x7f; |
| dt->tm_mon = BCD2BIN(val) - 1; |
| dt->tm_year = BCD2BIN(buf[6]); |
| if (buf[5] & 0x80) |
| dt->tm_year += 100; |
| |
| dev_dbg(&client->dev, "%s: secs=%d, mins=%d, " |
| "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n", |
| __FUNCTION__, dt->tm_sec, dt->tm_min, |
| dt->tm_hour, dt->tm_mday, |
| dt->tm_mon, dt->tm_year, dt->tm_wday); |
| |
| return 0; |
| } |
| |
| dev_err(&client->dev, "error reading data! %d\n", result); |
| return -EIO; |
| } |
| |
| static int ds1337_set_datetime(struct i2c_client *client, struct rtc_time *dt) |
| { |
| int result; |
| u8 buf[8]; |
| u8 val; |
| struct i2c_msg msg[1]; |
| |
| if (!dt) { |
| dev_dbg(&client->dev, "%s: EINVAL: dt=NULL\n", __FUNCTION__); |
| return -EINVAL; |
| } |
| |
| dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, " |
| "mday=%d, mon=%d, year=%d, wday=%d\n", __FUNCTION__, |
| dt->tm_sec, dt->tm_min, dt->tm_hour, |
| dt->tm_mday, dt->tm_mon, dt->tm_year, dt->tm_wday); |
| |
| buf[0] = 0; /* reg offset */ |
| buf[1] = BIN2BCD(dt->tm_sec); |
| buf[2] = BIN2BCD(dt->tm_min); |
| buf[3] = BIN2BCD(dt->tm_hour) | (1 << 6); |
| buf[4] = BIN2BCD(dt->tm_wday) + 1; |
| buf[5] = BIN2BCD(dt->tm_mday); |
| buf[6] = BIN2BCD(dt->tm_mon) + 1; |
| val = dt->tm_year; |
| if (val >= 100) { |
| val -= 100; |
| buf[6] |= (1 << 7); |
| } |
| buf[7] = BIN2BCD(val); |
| |
| msg[0].addr = client->addr; |
| msg[0].flags = 0; |
| msg[0].len = sizeof(buf); |
| msg[0].buf = &buf[0]; |
| |
| result = i2c_transfer(client->adapter, msg, 1); |
| if (result == 1) |
| return 0; |
| |
| dev_err(&client->dev, "error writing data! %d\n", result); |
| return -EIO; |
| } |
| |
| static int ds1337_command(struct i2c_client *client, unsigned int cmd, |
| void *arg) |
| { |
| dev_dbg(&client->dev, "%s: cmd=%d\n", __FUNCTION__, cmd); |
| |
| switch (cmd) { |
| case DS1337_GET_DATE: |
| return ds1337_get_datetime(client, arg); |
| |
| case DS1337_SET_DATE: |
| return ds1337_set_datetime(client, arg); |
| |
| default: |
| return -EINVAL; |
| } |
| } |
| |
| /* |
| * Public API for access to specific device. Useful for low-level |
| * RTC access from kernel code. |
| */ |
| int ds1337_do_command(int bus, int cmd, void *arg) |
| { |
| struct list_head *walk; |
| struct list_head *tmp; |
| struct ds1337_data *data; |
| |
| list_for_each_safe(walk, tmp, &ds1337_clients) { |
| data = list_entry(walk, struct ds1337_data, list); |
| if (data->client.adapter->nr == bus) |
| return ds1337_command(&data->client, cmd, arg); |
| } |
| |
| return -ENODEV; |
| } |
| |
| static int ds1337_attach_adapter(struct i2c_adapter *adapter) |
| { |
| return i2c_detect(adapter, &addr_data, ds1337_detect); |
| } |
| |
| /* |
| * The following function does more than just detection. If detection |
| * succeeds, it also registers the new chip. |
| */ |
| static int ds1337_detect(struct i2c_adapter *adapter, int address, int kind) |
| { |
| struct i2c_client *new_client; |
| struct ds1337_data *data; |
| int err = 0; |
| const char *name = ""; |
| |
| if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | |
| I2C_FUNC_I2C)) |
| goto exit; |
| |
| if (!(data = kmalloc(sizeof(struct ds1337_data), GFP_KERNEL))) { |
| err = -ENOMEM; |
| goto exit; |
| } |
| memset(data, 0, sizeof(struct ds1337_data)); |
| INIT_LIST_HEAD(&data->list); |
| |
| /* The common I2C client data is placed right before the |
| * DS1337-specific data. |
| */ |
| new_client = &data->client; |
| i2c_set_clientdata(new_client, data); |
| new_client->addr = address; |
| new_client->adapter = adapter; |
| new_client->driver = &ds1337_driver; |
| new_client->flags = 0; |
| |
| /* |
| * Now we do the remaining detection. A negative kind means that |
| * the driver was loaded with no force parameter (default), so we |
| * must both detect and identify the chip. A zero kind means that |
| * the driver was loaded with the force parameter, the detection |
| * step shall be skipped. A positive kind means that the driver |
| * was loaded with the force parameter and a given kind of chip is |
| * requested, so both the detection and the identification steps |
| * are skipped. |
| * |
| * For detection, we read registers that are most likely to cause |
| * detection failure, i.e. those that have more bits with fixed |
| * or reserved values. |
| */ |
| |
| /* Default to an DS1337 if forced */ |
| if (kind == 0) |
| kind = ds1337; |
| |
| if (kind < 0) { /* detection and identification */ |
| u8 data; |
| |
| /* Check that status register bits 6-2 are zero */ |
| if ((ds1337_read(new_client, DS1337_REG_STATUS, &data) < 0) || |
| (data & 0x7c)) |
| goto exit_free; |
| |
| /* Check for a valid day register value */ |
| if ((ds1337_read(new_client, DS1337_REG_DAY, &data) < 0) || |
| (data == 0) || (data & 0xf8)) |
| goto exit_free; |
| |
| /* Check for a valid date register value */ |
| if ((ds1337_read(new_client, DS1337_REG_DATE, &data) < 0) || |
| (data == 0) || (data & 0xc0) || ((data & 0x0f) > 9) || |
| (data >= 0x32)) |
| goto exit_free; |
| |
| /* Check for a valid month register value */ |
| if ((ds1337_read(new_client, DS1337_REG_MONTH, &data) < 0) || |
| (data == 0) || (data & 0x60) || ((data & 0x0f) > 9) || |
| ((data >= 0x13) && (data <= 0x19))) |
| goto exit_free; |
| |
| /* Check that control register bits 6-5 are zero */ |
| if ((ds1337_read(new_client, DS1337_REG_CONTROL, &data) < 0) || |
| (data & 0x60)) |
| goto exit_free; |
| |
| kind = ds1337; |
| } |
| |
| if (kind == ds1337) |
| name = "ds1337"; |
| |
| /* We can fill in the remaining client fields */ |
| strlcpy(new_client->name, name, I2C_NAME_SIZE); |
| |
| /* Tell the I2C layer a new client has arrived */ |
| if ((err = i2c_attach_client(new_client))) |
| goto exit_free; |
| |
| /* Initialize the DS1337 chip */ |
| ds1337_init_client(new_client); |
| |
| /* Add client to local list */ |
| list_add(&data->list, &ds1337_clients); |
| |
| return 0; |
| |
| exit_free: |
| kfree(data); |
| exit: |
| return err; |
| } |
| |
| static void ds1337_init_client(struct i2c_client *client) |
| { |
| s32 val; |
| |
| /* Ensure that device is set in 24-hour mode */ |
| val = i2c_smbus_read_byte_data(client, DS1337_REG_HOUR); |
| if ((val >= 0) && (val & (1 << 6)) == 0) |
| i2c_smbus_write_byte_data(client, DS1337_REG_HOUR, |
| val | (1 << 6)); |
| } |
| |
| static int ds1337_detach_client(struct i2c_client *client) |
| { |
| int err; |
| struct ds1337_data *data = i2c_get_clientdata(client); |
| |
| if ((err = i2c_detach_client(client))) { |
| dev_err(&client->dev, "Client deregistration failed, " |
| "client not detached.\n"); |
| return err; |
| } |
| |
| list_del(&data->list); |
| kfree(data); |
| return 0; |
| } |
| |
| static int __init ds1337_init(void) |
| { |
| return i2c_add_driver(&ds1337_driver); |
| } |
| |
| static void __exit ds1337_exit(void) |
| { |
| i2c_del_driver(&ds1337_driver); |
| } |
| |
| MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); |
| MODULE_DESCRIPTION("DS1337 RTC driver"); |
| MODULE_LICENSE("GPL"); |
| |
| EXPORT_SYMBOL_GPL(ds1337_do_command); |
| |
| module_init(ds1337_init); |
| module_exit(ds1337_exit); |