diff --git a/kernel/chips/ds1307.c b/kernel/chips/ds1307.c new file mode 100644 index 00000000..2f1f40b2 --- /dev/null +++ b/kernel/chips/ds1307.c @@ -0,0 +1,367 @@ + +/* + * linux/drivers/i2c/ds1307.c + * + * Author: Abraham van der Merwe + * + * Linux support for the Dallas Semiconductor DS1307 Serial Real-Time + * Clock. + * + * Based on code from the lm-sensors project which is available + * at http://www.lm-sensors.nu/ and Russell King's PCF8583 Real-Time + * Clock driver (linux/drivers/acorn/char/pcf8583.c). + * + * This source code 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. + */ + +#include +#include +#include + +#include +#include +#include +#include +#include + +#include + +#include "ds1307.h" + +#define BCD_TO_BIN(x) (((x) & 15) + ((x) >> 4) * 10) +#define BIN_TO_BCD(x) ((((x) / 10) << 4) + (x) % 10) + +static struct i2c_driver ds1307; +static DECLARE_MUTEX (mutex); + +/* + * The DS1307 Real-Time Clock wants the address in a different + * message, so we can't use the normal i2c_master_recv() routine + * for receiving data. + */ +static int ds1307_i2c_recv (struct i2c_client *client,char *buf,char addr,int count) +{ + struct i2c_msg msg[] = { + { addr: client->addr, flags: 0, len: 1, buf: &addr }, + { addr: client->addr, flags: I2C_M_RD, len: count, buf: buf } + }; + int result = 0; + + if (down_interruptible (&mutex)) + return (-ERESTARTSYS); + + if (i2c_transfer (client->adapter,msg,2) != 2) + result = -EIO; + + up (&mutex); + + return (result); +} + +/* + * Would've been nice to specify the address to this as well, but then we + * would need to copy the buffer twice - not worth it... + */ +static int ds1307_i2c_send (struct i2c_client *client,const char *buf,int count) +{ + int result = 0; + + if (down_interruptible (&mutex)) + return (-ERESTARTSYS); + + if (i2c_master_send (client,(const char *) buf,count) != count) + result = -EIO; + + up (&mutex); + + return (result); +} + +static int ds1307_attach (struct i2c_adapter *adapter,int addr,unsigned short flags,int kind) +{ + struct i2c_client *client; + int result; + + if ((client = (struct i2c_client *) kmalloc (sizeof (struct i2c_client),GFP_KERNEL)) == NULL) + return (-ENOMEM); + + strcpy (client->name,ds1307.name); + client->id = ds1307.id; + client->flags = I2C_CLIENT_ALLOW_USE | I2C_CLIENT_ALLOW_MULTIPLE_USE; + client->addr = addr; + client->adapter = adapter; + client->driver = &ds1307; + client->data = NULL; + + if ((result = i2c_attach_client (client))) { + kfree (client); + return (result); + } + + return (0); +} + +static int ds1307_attach_adapter (struct i2c_adapter *adapter) +{ + static unsigned short ignore[] = { I2C_CLIENT_END }; + static unsigned short addr[] = { 0x68, I2C_CLIENT_END }; + static struct i2c_client_address_data ds1307_addr_data = { + normal_i2c: addr, + normal_i2c_range: ignore, + probe: ignore, + probe_range: ignore, + ignore: ignore, + ignore_range: ignore, + force: ignore + }; + + return (i2c_probe (adapter,&ds1307_addr_data,ds1307_attach)); +} + +static int ds1307_detach_client (struct i2c_client *client) +{ + int result; + + if ((result = i2c_detach_client (client))) + return (result); + + kfree (client); + + return (0); +} + +static int ds1307_getdate (struct i2c_client *client,void *arg) +{ + struct ds1307_date *date = (struct ds1307_date *) arg; + u8 buf[7]; + + /* this also enables the oscillator */ + memset (buf,0,7); + + /* enable 24-hour mode */ + buf[2] = 0x40; + + if (ds1307_i2c_recv (client,(char *) buf,0,7) < 0) + return (-EIO); + + date->tm_sec = BCD_TO_BIN (buf[0] & ~0x80); + date->tm_min = BCD_TO_BIN (buf[1]); + date->tm_hour = BCD_TO_BIN (buf[2] & 0x3f); + date->tm_wday = BCD_TO_BIN (buf[3]) - 1; + date->tm_mday = BCD_TO_BIN (buf[4]); + date->tm_mon = BCD_TO_BIN (buf[5]) - 1; + date->tm_year = BCD_TO_BIN (buf[6]) + 100; + + return (0); +} + +static int ds1307_setdate (struct i2c_client *client,void *arg) +{ + struct ds1307_date *date = (struct ds1307_date *) arg; + u8 buf[8]; + + /* select address 0 */ + buf[0] = 0; + + buf[1] = BIN_TO_BCD (date->tm_sec); + buf[2] = BIN_TO_BCD (date->tm_min); + buf[3] = BIN_TO_BCD (date->tm_hour) | 0x40; + buf[4] = BIN_TO_BCD (date->tm_wday + 1); + buf[5] = BIN_TO_BCD (date->tm_mday); + buf[6] = BIN_TO_BCD (date->tm_mon + 1); + buf[7] = BIN_TO_BCD (date->tm_year - 100); + + return (ds1307_i2c_send (client,(const char *) buf,8)); +} + +static int ds1307_enable (struct i2c_client *client,void *arg) +{ + u8 buf[2]; + + if (ds1307_i2c_recv (client,(char *) buf + 1,0,1) < 0) + return (-EIO); + + if ((buf[1] & 0x80)) { + buf[0] = 0, buf[1] &= ~0x80; + return (ds1307_i2c_send (client,(const char *) buf,2)); + } + + return (0); +} + +static int ds1307_irqon (struct i2c_client *client,void *arg) +{ + u8 buf[2]; + + if (ds1307_i2c_recv (client,(char *) buf + 1,7,1) < 0) + return (-EIO); + + buf[0] = 7; + buf[1] |= 0x10; + + return (ds1307_i2c_send (client,(const char *) buf,2)); +} + +static int ds1307_irqoff (struct i2c_client *client,void *arg) +{ + u8 buf[2]; + + if (ds1307_i2c_recv (client,(char *) buf + 1,7,1) < 0) + return (-EIO); + + buf[0] = 7; + buf[1] &= ~0x10; + + return (ds1307_i2c_send (client,(const char *) buf,2)); +} + +static int ds1307_getfreq (struct i2c_client *client,void *arg) +{ + u16 *freq = (u16 *) arg; + u8 buf; + static const u16 table[] = { + DS1307_FREQ_1HZ, + DS1307_FREQ_4KHZ, + DS1307_FREQ_8KHZ, + DS1307_FREQ_32KHZ + }; + + if (ds1307_i2c_recv (client,(char *) &buf,7,1) < 0) + return (-EIO); + + *freq = table[buf & 3]; + + return (0); +} + +static int ds1307_setfreq (struct i2c_client *client,void *arg) +{ + u16 *freq = (u16 *) arg; + u8 buf[2]; + + /* select address 7 */ + buf[0] = 7; + + /* default to 1HZ */ + buf[1] = 0; + + switch (*freq) { + case DS1307_FREQ_32KHZ: buf[1]++; + case DS1307_FREQ_8KHZ: buf[1]++; + case DS1307_FREQ_4KHZ: buf[1]++; + case DS1307_FREQ_1HZ: break; + default: + return (-EINVAL); + } + + return (ds1307_i2c_send (client,(const char *) buf,2)); +} + +static int ds1307_read (struct i2c_client *client,void *arg) +{ + struct ds1307_memory *mem = (struct ds1307_memory *) arg; + u8 buf[DS1307_SIZE]; + + if (mem->offset >= DS1307_SIZE || mem->offset + mem->length > DS1307_SIZE) + return (-EINVAL); + + if (ds1307_i2c_recv (client,(char *) buf,mem->offset + 8,mem->length) < 0) + return (-EIO); + + memcpy (mem->buf,buf,mem->length); + + return (0); +} + +static int ds1307_write (struct i2c_client *client,void *arg) +{ + struct ds1307_memory *mem = (struct ds1307_memory *) arg; + u8 buf[DS1307_SIZE + 1]; + + if (mem->offset >= DS1307_SIZE || mem->offset + mem->length > DS1307_SIZE) + return (-EINVAL); + + buf[0] = mem->offset + 8; + + memcpy (buf + 1,mem->buf,mem->length); + + return (ds1307_i2c_send (client,(const char *) buf,mem->length + 1)); +} + +static int ds1307_command (struct i2c_client *client,unsigned int cmd,void *arg) +{ + static const struct { + int cmd; + int (*function) (struct i2c_client *,void *arg); + } ioctl[] = { + { DS1307_ENABLE, ds1307_enable }, + { DS1307_GET_DATE, ds1307_getdate }, + { DS1307_SET_DATE, ds1307_setdate }, + { DS1307_IRQ_ON, ds1307_irqon }, + { DS1307_IRQ_OFF, ds1307_irqoff }, + { DS1307_GET_FREQ, ds1307_getfreq }, + { DS1307_SET_FREQ, ds1307_setfreq }, + { DS1307_READ, ds1307_read }, + { DS1307_WRITE, ds1307_write } + }; + int i; + + for (i = 0; i < sizeof (ioctl) / sizeof (ioctl[0]); i++) + if (ioctl[i].cmd == cmd) + return (ioctl[i].function (client,arg)); + + return (-EINVAL); +} + +static void ds1307_inc_use (struct i2c_client *client) +{ + MOD_INC_USE_COUNT; +} + +static void ds1307_dec_use (struct i2c_client *client) +{ + MOD_DEC_USE_COUNT; +} + +static struct i2c_driver ds1307 = { + name: "ds1307", + id: I2C_DRIVERID_DS1307, + flags: I2C_DF_NOTIFY, + attach_adapter: ds1307_attach_adapter, + detach_client: ds1307_detach_client, + command: ds1307_command, + inc_use: ds1307_inc_use, + dec_use: ds1307_dec_use +}; + +static int __init ds1307_init (void) +{ + int result; + + if ((result = i2c_add_driver (&ds1307))) + return (result); + + printk ("Dallas Semiconductor DS1307 Real-Time Clock driver (V0.03)\n"); + + return (0); +} + +static void __exit ds1307_exit (void) +{ + i2c_del_driver (&ds1307); +} + +EXPORT_NO_SYMBOLS; + +MODULE_AUTHOR ("Abraham van der Merwe "); +MODULE_DESCRIPTION ("Linux support for DS1307 Real-Time Clock"); + +#ifdef MODULE_LICENSE +MODULE_LICENSE ("GPL"); +#endif /* #ifdef MODULE_LICENSE */ + +module_init (ds1307_init); +module_exit (ds1307_exit); + diff --git a/kernel/include/ds1307.h b/kernel/include/ds1307.h new file mode 100644 index 00000000..688caf20 --- /dev/null +++ b/kernel/include/ds1307.h @@ -0,0 +1,59 @@ +#ifndef DS1307_H +#define DS1307_H + +/* + * linux/include/linux/ds1307.h + * + * Author: Abraham van der Merwe + * + * Linux support for the Dallas Semiconductor DS1307 Serial Real-Time + * Clock. + * + * Based on code from the lm-sensors project which is available + * at http://www.lm-sensors.nu/ and Russell King's PCF8583 Real-Time + * Clock driver (linux/drivers/acorn/char/pcf8583.c). + * + * This source code 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. + */ + +#include + +/* practically the same as struct rtc_time, but without tm_yday and tm_isdst */ +struct ds1307_date { + int tm_sec; + int tm_min; + int tm_hour; + int tm_mday; + int tm_mon; + int tm_year; + int tm_wday; +}; + +struct ds1307_memory { + u8 offset; /* 0 - 55 */ + u8 buf[56]; /* data */ + u8 length; /* offset + length <= 50 */ +}; + +/* size of the rtc non-volatile ram */ +#define DS1307_SIZE 56 + +/* the following frequencies are supported */ +#define DS1307_FREQ_1HZ 1 +#define DS1307_FREQ_4KHZ 4096 +#define DS1307_FREQ_8KHZ 8192 +#define DS1307_FREQ_32KHZ 32768 + +#define DS1307_GET_DATE _IOR ('d',0,struct ds1307_date *) +#define DS1307_SET_DATE _IOW ('d',1,struct ds1307_date *) +#define DS1307_IRQ_ON _IO ('d',2) +#define DS1307_IRQ_OFF _IO ('d',3) +#define DS1307_GET_FREQ _IOR ('d',4,u16 *) +#define DS1307_SET_FREQ _IOW ('d',5,u16 *) +#define DS1307_READ _IOR ('d',6,struct ds1307_memory *) +#define DS1307_WRITE _IOW ('d',7,struct ds1307_memory *) +#define DS1307_ENABLE _IO ('d',8) + +#endif /* #ifdef DS1307_H */