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>
20 static struct i2c_driver pcf8583_driver;
22 static unsigned short ignore[] = { I2C_CLIENT_END };
23 static unsigned short normal_addr[] = { 0x50, I2C_CLIENT_END };
25 static struct i2c_client_address_data addr_data = {
26 normal_i2c: normal_addr,
27 normal_i2c_range: ignore,
35 #define DAT(x) ((unsigned int)(x->data))
38 pcf8583_attach(struct i2c_adapter *adap, int addr, unsigned short flags,
42 unsigned char buf[1], ad[1] = { 0 };
43 struct i2c_msg msgs[2] = {
45 { addr, I2C_M_RD, 1, buf }
48 c = kmalloc(sizeof(*c), GFP_KERNEL);
52 strcpy(c->name, "PCF8583");
53 c->id = pcf8583_driver.id;
57 c->driver = &pcf8583_driver;
60 if (i2c_transfer(c->adapter, msgs, 2) == 2)
63 return i2c_attach_client(c);
67 pcf8583_probe(struct i2c_adapter *adap)
69 return i2c_probe(adap, &addr_data, pcf8583_attach);
73 pcf8583_detach(struct i2c_client *client)
75 i2c_detach_client(client);
81 pcf8583_get_datetime(struct i2c_client *client, struct rtc_tm *dt)
83 unsigned char buf[8], addr[1] = { 1 };
84 struct i2c_msg msgs[2] = {
85 { client->addr, 0, 1, addr },
86 { client->addr, I2C_M_RD, 6, buf }
90 memset(buf, 0, sizeof(buf));
92 ret = i2c_transfer(client->adapter, msgs, 2);
94 dt->year_off = buf[4] >> 6;
95 dt->wday = buf[5] >> 5;
100 dt->cs = BCD_TO_BIN(buf[0]);
101 dt->secs = BCD_TO_BIN(buf[1]);
102 dt->mins = BCD_TO_BIN(buf[2]);
103 dt->hours = BCD_TO_BIN(buf[3]);
104 dt->mday = BCD_TO_BIN(buf[4]);
105 dt->mon = BCD_TO_BIN(buf[5]);
114 pcf8583_set_datetime(struct i2c_client *client, struct rtc_tm *dt, int datetoo)
116 unsigned char buf[8];
120 buf[1] = DAT(client) | 0x80;
121 buf[2] = BIN_TO_BCD(dt->cs);
122 buf[3] = BIN_TO_BCD(dt->secs);
123 buf[4] = BIN_TO_BCD(dt->mins);
124 buf[5] = BIN_TO_BCD(dt->hours);
128 buf[6] = BIN_TO_BCD(dt->mday) | (dt->year_off << 6);
129 buf[7] = BIN_TO_BCD(dt->mon) | (dt->wday << 5);
132 ret = i2c_master_send(client, (char *)buf, len);
136 buf[1] = DAT(client);
137 i2c_master_send(client, (char *)buf, 2);
143 pcf8583_get_ctrl(struct i2c_client *client, unsigned char *ctrl)
150 pcf8583_set_ctrl(struct i2c_client *client, unsigned char *ctrl)
152 unsigned char buf[2];
158 return i2c_master_send(client, (char *)buf, 2);
162 pcf8583_read_mem(struct i2c_client *client, struct mem *mem)
164 unsigned char addr[1];
165 struct i2c_msg msgs[2] = {
166 { client->addr, 0, 1, addr },
167 { client->addr, I2C_M_RD, 0, mem->data }
174 msgs[1].len = mem->nr;
176 return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO;
180 pcf8583_write_mem(struct i2c_client *client, struct mem *mem)
182 unsigned char addr[1];
183 struct i2c_msg msgs[2] = {
184 { client->addr, 0, 1, addr },
185 { client->addr, 0, 0, mem->data }
192 msgs[1].len = mem->nr;
194 return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO;
198 pcf8583_command(struct i2c_client *client, unsigned int cmd, void *arg)
201 case RTC_GETDATETIME:
202 return pcf8583_get_datetime(client, arg);
205 return pcf8583_set_datetime(client, arg, 0);
207 case RTC_SETDATETIME:
208 return pcf8583_set_datetime(client, arg, 1);
211 return pcf8583_get_ctrl(client, arg);
214 return pcf8583_set_ctrl(client, arg);
217 return pcf8583_read_mem(client, arg);
220 return pcf8583_write_mem(client, arg);
227 static struct i2c_driver pcf8583_driver = {
229 id: I2C_DRIVERID_PCF8583,
230 flags: I2C_DF_NOTIFY,
231 attach_adapter: pcf8583_probe,
232 detach_client: pcf8583_detach,
233 command: pcf8583_command
236 static __init int pcf8583_init(void)
238 return i2c_add_driver(&pcf8583_driver);
241 __initcall(pcf8583_init);