2 * linux/drivers/acorn/char/pcf8583.c
4 * Copyright (C) 2000 Russell King
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 * Driver for PCF8583 RTC & RAM chip
12 #include <linux/i2c.h>
13 #include <linux/slab.h>
14 #include <linux/string.h>
15 #include <linux/mc146818rtc.h>
16 #include <linux/init.h>
17 #include <linux/errno.h>
18 #include <linux/bcd.h>
22 static struct i2c_driver pcf8583_driver;
24 static unsigned short ignore[] = { I2C_CLIENT_END };
25 static unsigned short normal_addr[] = { 0x50, I2C_CLIENT_END };
27 static struct i2c_client_address_data addr_data = {
28 .normal_i2c = normal_addr,
34 #define DAT(x) ((unsigned int)(x->dev.driver_data))
37 pcf8583_attach(struct i2c_adapter *adap, int addr, int kind)
40 unsigned char buf[1], ad[1] = { 0 };
41 struct i2c_msg msgs[2] = {
43 { addr, I2C_M_RD, 1, buf }
46 c = kmalloc(sizeof(*c), GFP_KERNEL);
50 memset(c, 0, sizeof(*c));
53 c->driver = &pcf8583_driver;
55 if (i2c_transfer(c->adapter, msgs, 2) == 2)
58 return i2c_attach_client(c);
62 pcf8583_probe(struct i2c_adapter *adap)
64 return i2c_probe(adap, &addr_data, pcf8583_attach);
68 pcf8583_detach(struct i2c_client *client)
70 i2c_detach_client(client);
76 pcf8583_get_datetime(struct i2c_client *client, struct rtc_tm *dt)
78 unsigned char buf[8], addr[1] = { 1 };
79 struct i2c_msg msgs[2] = {
80 { client->addr, 0, 1, addr },
81 { client->addr, I2C_M_RD, 6, buf }
85 memset(buf, 0, sizeof(buf));
87 ret = i2c_transfer(client->adapter, msgs, 2);
89 dt->year_off = buf[4] >> 6;
90 dt->wday = buf[5] >> 5;
95 dt->cs = BCD_TO_BIN(buf[0]);
96 dt->secs = BCD_TO_BIN(buf[1]);
97 dt->mins = BCD_TO_BIN(buf[2]);
98 dt->hours = BCD_TO_BIN(buf[3]);
99 dt->mday = BCD_TO_BIN(buf[4]);
100 dt->mon = BCD_TO_BIN(buf[5]);
109 pcf8583_set_datetime(struct i2c_client *client, struct rtc_tm *dt, int datetoo)
111 unsigned char buf[8];
115 buf[1] = DAT(client) | 0x80;
116 buf[2] = BIN_TO_BCD(dt->cs);
117 buf[3] = BIN_TO_BCD(dt->secs);
118 buf[4] = BIN_TO_BCD(dt->mins);
119 buf[5] = BIN_TO_BCD(dt->hours);
123 buf[6] = BIN_TO_BCD(dt->mday) | (dt->year_off << 6);
124 buf[7] = BIN_TO_BCD(dt->mon) | (dt->wday << 5);
127 ret = i2c_master_send(client, (char *)buf, len);
131 buf[1] = DAT(client);
132 i2c_master_send(client, (char *)buf, 2);
138 pcf8583_get_ctrl(struct i2c_client *client, unsigned char *ctrl)
145 pcf8583_set_ctrl(struct i2c_client *client, unsigned char *ctrl)
147 unsigned char buf[2];
153 return i2c_master_send(client, (char *)buf, 2);
157 pcf8583_read_mem(struct i2c_client *client, struct mem *mem)
159 unsigned char addr[1];
160 struct i2c_msg msgs[2] = {
161 { client->addr, 0, 1, addr },
162 { client->addr, I2C_M_RD, 0, mem->data }
169 msgs[1].len = mem->nr;
171 return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO;
175 pcf8583_write_mem(struct i2c_client *client, struct mem *mem)
177 unsigned char addr[1];
178 struct i2c_msg msgs[2] = {
179 { client->addr, 0, 1, addr },
180 { client->addr, 0, 0, mem->data }
187 msgs[1].len = mem->nr;
189 return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO;
193 pcf8583_command(struct i2c_client *client, unsigned int cmd, void *arg)
196 case RTC_GETDATETIME:
197 return pcf8583_get_datetime(client, arg);
200 return pcf8583_set_datetime(client, arg, 0);
202 case RTC_SETDATETIME:
203 return pcf8583_set_datetime(client, arg, 1);
206 return pcf8583_get_ctrl(client, arg);
209 return pcf8583_set_ctrl(client, arg);
212 return pcf8583_read_mem(client, arg);
215 return pcf8583_write_mem(client, arg);
222 static struct i2c_driver pcf8583_driver = {
224 .id = I2C_DRIVERID_PCF8583,
225 .flags = I2C_DF_NOTIFY,
226 .attach_adapter = pcf8583_probe,
227 .detach_client = pcf8583_detach,
228 .command = pcf8583_command
231 static __init int pcf8583_init(void)
233 return i2c_add_driver(&pcf8583_driver);
236 __initcall(pcf8583_init);