1 /*
2 * linux/drivers/acorn/char/pcf8583.c
3 *
4 * Copyright (C) 2000 Russell King
5 *
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.
9 *
10 * Driver for PCF8583 RTC & RAM chip
11 */
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
18 #include "pcf8583.h"
19
20 static struct i2c_driver pcf8583_driver;
21
22 static unsigned short ignore[] = { I2C_CLIENT_END };
23 static unsigned short normal_addr[] = { 0x50, I2C_CLIENT_END };
24
25 static struct i2c_client_address_data addr_data = {
26 normal_i2c: normal_addr,
27 normal_i2c_range: ignore,
28 probe: ignore,
29 probe_range: ignore,
30 ignore: ignore,
31 ignore_range: ignore,
32 force: ignore,
33 };
34
35 #define DAT(x) ((unsigned int)(x->data))
36
37 static int
pcf8583_attach(struct i2c_adapter * adap,int addr,unsigned short flags,int kind)38 pcf8583_attach(struct i2c_adapter *adap, int addr, unsigned short flags,
39 int kind)
40 {
41 struct i2c_client *c;
42 unsigned char buf[1], ad[1] = { 0 };
43 struct i2c_msg msgs[2] = {
44 { addr, 0, 1, ad },
45 { addr, I2C_M_RD, 1, buf }
46 };
47
48 c = kmalloc(sizeof(*c), GFP_KERNEL);
49 if (!c)
50 return -ENOMEM;
51
52 strcpy(c->name, "PCF8583");
53 c->id = pcf8583_driver.id;
54 c->flags = 0;
55 c->addr = addr;
56 c->adapter = adap;
57 c->driver = &pcf8583_driver;
58 c->data = NULL;
59
60 if (i2c_transfer(c->adapter, msgs, 2) == 2)
61 DAT(c) = buf[0];
62
63 return i2c_attach_client(c);
64 }
65
66 static int
pcf8583_probe(struct i2c_adapter * adap)67 pcf8583_probe(struct i2c_adapter *adap)
68 {
69 return i2c_probe(adap, &addr_data, pcf8583_attach);
70 }
71
72 static int
pcf8583_detach(struct i2c_client * client)73 pcf8583_detach(struct i2c_client *client)
74 {
75 i2c_detach_client(client);
76 kfree(client);
77 return 0;
78 }
79
80 static int
pcf8583_get_datetime(struct i2c_client * client,struct rtc_tm * dt)81 pcf8583_get_datetime(struct i2c_client *client, struct rtc_tm *dt)
82 {
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 }
87 };
88 int ret = -EIO;
89
90 memset(buf, 0, sizeof(buf));
91
92 ret = i2c_transfer(client->adapter, msgs, 2);
93 if (ret == 2) {
94 dt->year_off = buf[4] >> 6;
95 dt->wday = buf[5] >> 5;
96
97 buf[4] &= 0x3f;
98 buf[5] &= 0x1f;
99
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]);
106
107 ret = 0;
108 }
109
110 return ret;
111 }
112
113 static int
pcf8583_set_datetime(struct i2c_client * client,struct rtc_tm * dt,int datetoo)114 pcf8583_set_datetime(struct i2c_client *client, struct rtc_tm *dt, int datetoo)
115 {
116 unsigned char buf[8];
117 int ret, len = 6;
118
119 buf[0] = 0;
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);
125
126 if (datetoo) {
127 len = 8;
128 buf[6] = BIN_TO_BCD(dt->mday) | (dt->year_off << 6);
129 buf[7] = BIN_TO_BCD(dt->mon) | (dt->wday << 5);
130 }
131
132 ret = i2c_master_send(client, (char *)buf, len);
133 if (ret == len)
134 ret = 0;
135
136 buf[1] = DAT(client);
137 i2c_master_send(client, (char *)buf, 2);
138
139 return ret;
140 }
141
142 static int
pcf8583_get_ctrl(struct i2c_client * client,unsigned char * ctrl)143 pcf8583_get_ctrl(struct i2c_client *client, unsigned char *ctrl)
144 {
145 *ctrl = DAT(client);
146 return 0;
147 }
148
149 static int
pcf8583_set_ctrl(struct i2c_client * client,unsigned char * ctrl)150 pcf8583_set_ctrl(struct i2c_client *client, unsigned char *ctrl)
151 {
152 unsigned char buf[2];
153
154 buf[0] = 0;
155 buf[1] = *ctrl;
156 DAT(client) = *ctrl;
157
158 return i2c_master_send(client, (char *)buf, 2);
159 }
160
161 static int
pcf8583_read_mem(struct i2c_client * client,struct mem * mem)162 pcf8583_read_mem(struct i2c_client *client, struct mem *mem)
163 {
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 }
168 };
169
170 if (mem->loc < 8)
171 return -EINVAL;
172
173 addr[0] = mem->loc;
174 msgs[1].len = mem->nr;
175
176 return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO;
177 }
178
179 static int
pcf8583_write_mem(struct i2c_client * client,struct mem * mem)180 pcf8583_write_mem(struct i2c_client *client, struct mem *mem)
181 {
182 unsigned char addr[1];
183 struct i2c_msg msgs[2] = {
184 { client->addr, 0, 1, addr },
185 { client->addr, 0, 0, mem->data }
186 };
187
188 if (mem->loc < 8)
189 return -EINVAL;
190
191 addr[0] = mem->loc;
192 msgs[1].len = mem->nr;
193
194 return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO;
195 }
196
197 static int
pcf8583_command(struct i2c_client * client,unsigned int cmd,void * arg)198 pcf8583_command(struct i2c_client *client, unsigned int cmd, void *arg)
199 {
200 switch (cmd) {
201 case RTC_GETDATETIME:
202 return pcf8583_get_datetime(client, arg);
203
204 case RTC_SETTIME:
205 return pcf8583_set_datetime(client, arg, 0);
206
207 case RTC_SETDATETIME:
208 return pcf8583_set_datetime(client, arg, 1);
209
210 case RTC_GETCTRL:
211 return pcf8583_get_ctrl(client, arg);
212
213 case RTC_SETCTRL:
214 return pcf8583_set_ctrl(client, arg);
215
216 case MEM_READ:
217 return pcf8583_read_mem(client, arg);
218
219 case MEM_WRITE:
220 return pcf8583_write_mem(client, arg);
221
222 default:
223 return -EINVAL;
224 }
225 }
226
227 static struct i2c_driver pcf8583_driver = {
228 name: "PCF8583",
229 id: I2C_DRIVERID_PCF8583,
230 flags: I2C_DF_NOTIFY,
231 attach_adapter: pcf8583_probe,
232 detach_client: pcf8583_detach,
233 command: pcf8583_command
234 };
235
pcf8583_init(void)236 static __init int pcf8583_init(void)
237 {
238 return i2c_add_driver(&pcf8583_driver);
239 }
240
241 __initcall(pcf8583_init);
242