848910ff3c9c77c5e6b722e14e6cb11006413f2d
[linux-2.6.git] / drivers / media / dvb / b2c2 / flexcop-i2c.c
1 /*
2  * This file is part of linux driver the digital TV devices equipped with B2C2 FlexcopII(b)/III
3  *
4  * flexcop-i2c.c - flexcop internal 2Wire bus (I2C) and dvb i2c initialization
5  *
6  * see flexcop.c for copyright information.
7  */
8 #include "flexcop.h"
9
10 #define FC_MAX_I2C_RETRIES 100000
11
12 static int flexcop_i2c_operation(struct flexcop_device *fc, flexcop_ibi_value *r100)
13 {
14         int i;
15         flexcop_ibi_value r;
16
17         r100->tw_sm_c_100.working_start = 1;
18         deb_i2c("r100 before: %08x\n",r100->raw);
19
20         fc->write_ibi_reg(fc, tw_sm_c_100, ibi_zero);
21         fc->write_ibi_reg(fc, tw_sm_c_100, *r100); /* initiating i2c operation */
22
23         for (i = 0; i < FC_MAX_I2C_RETRIES; i++) {
24                 r = fc->read_ibi_reg(fc, tw_sm_c_100);
25
26                 if (!r.tw_sm_c_100.no_base_addr_ack_error) {
27                         if (r.tw_sm_c_100.st_done) {  /* && !r.tw_sm_c_100.working_start */
28                                 *r100 = r;
29                                 deb_i2c("i2c success\n");
30                                 return 0;
31                         }
32                 } else {
33                         deb_i2c("suffering from an i2c ack_error\n");
34                         return -EREMOTEIO;
35                 }
36         }
37         deb_i2c("tried %d times i2c operation, never finished or too many ack errors.\n",i);
38         return -EREMOTEIO;
39 }
40
41 static int flexcop_i2c_read4(struct flexcop_device *fc, flexcop_ibi_value r100, u8 *buf)
42 {
43         flexcop_ibi_value r104;
44         int len = r100.tw_sm_c_100.total_bytes, /* remember total_bytes is buflen-1 */
45                 ret;
46
47         if ((ret = flexcop_i2c_operation(fc,&r100)) != 0) {
48                 /* The Cablestar needs a different kind of i2c-transfer (does not
49                  * support "Repeat Start"):
50                  * wait for the ACK failure,
51                  * and do a subsequent read with the Bit 30 enabled
52                  */
53                 r100.tw_sm_c_100.no_base_addr_ack_error = 1;
54                 if ((ret = flexcop_i2c_operation(fc,&r100)) != 0) {
55                         deb_i2c("no_base_addr read failed. %d\n",ret);
56                         return ret;
57                 }
58         }
59
60         buf[0] = r100.tw_sm_c_100.data1_reg;
61
62         if (len > 0) {
63                 r104 = fc->read_ibi_reg(fc,tw_sm_c_104);
64                 deb_i2c("read: r100: %08x, r104: %08x\n",r100.raw,r104.raw);
65
66                 /* there is at least one more byte, otherwise we wouldn't be here */
67                 buf[1] = r104.tw_sm_c_104.data2_reg;
68                 if (len > 1) buf[2] = r104.tw_sm_c_104.data3_reg;
69                 if (len > 2) buf[3] = r104.tw_sm_c_104.data4_reg;
70         }
71
72         return 0;
73 }
74
75 static int flexcop_i2c_write4(struct flexcop_device *fc, flexcop_ibi_value r100, u8 *buf)
76 {
77         flexcop_ibi_value r104;
78         int len = r100.tw_sm_c_100.total_bytes; /* remember total_bytes is buflen-1 */
79         r104.raw = 0;
80
81         /* there is at least one byte, otherwise we wouldn't be here */
82         r100.tw_sm_c_100.data1_reg = buf[0];
83
84         r104.tw_sm_c_104.data2_reg = len > 0 ? buf[1] : 0;
85         r104.tw_sm_c_104.data3_reg = len > 1 ? buf[2] : 0;
86         r104.tw_sm_c_104.data4_reg = len > 2 ? buf[3] : 0;
87
88         deb_i2c("write: r100: %08x, r104: %08x\n",r100.raw,r104.raw);
89
90         /* write the additional i2c data before doing the actual i2c operation */
91         fc->write_ibi_reg(fc,tw_sm_c_104,r104);
92         return flexcop_i2c_operation(fc,&r100);
93 }
94
95 int flexcop_i2c_request(struct flexcop_device *fc, flexcop_access_op_t op,
96                 flexcop_i2c_port_t port, u8 chipaddr, u8 addr, u8 *buf, u16 len)
97 {
98         int ret;
99         u16 bytes_to_transfer;
100         flexcop_ibi_value r100;
101
102         deb_i2c("op = %d\n",op);
103         r100.raw = 0;
104         r100.tw_sm_c_100.chipaddr = chipaddr;
105         r100.tw_sm_c_100.twoWS_rw = op;
106         r100.tw_sm_c_100.twoWS_port_reg = port;
107
108         while (len != 0) {
109                 bytes_to_transfer = len > 4 ? 4 : len;
110
111                 r100.tw_sm_c_100.total_bytes = bytes_to_transfer - 1;
112                 r100.tw_sm_c_100.baseaddr = addr;
113
114                 if (op == FC_READ)
115                         ret = flexcop_i2c_read4(fc, r100, buf);
116                 else
117                         ret = flexcop_i2c_write4(fc,r100, buf);
118
119                 if (ret < 0)
120                         return ret;
121
122                 buf  += bytes_to_transfer;
123                 addr += bytes_to_transfer;
124                 len  -= bytes_to_transfer;
125         };
126
127         return 0;
128 }
129 /* exported for PCI i2c */
130 EXPORT_SYMBOL(flexcop_i2c_request);
131
132 /* master xfer callback for demodulator */
133 static int flexcop_master_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num)
134 {
135         struct flexcop_device *fc = i2c_get_adapdata(i2c_adap);
136         int i, ret = 0;
137
138         if (down_interruptible(&fc->i2c_sem))
139                 return -ERESTARTSYS;
140
141         /* reading */
142         if (num == 2 &&
143                 msgs[0].flags == 0 &&
144                 msgs[1].flags == I2C_M_RD &&
145                 msgs[0].buf != NULL &&
146                 msgs[1].buf != NULL) {
147
148                 ret = fc->i2c_request(fc, FC_READ, FC_I2C_PORT_DEMOD, msgs[0].addr, msgs[0].buf[0], msgs[1].buf, msgs[1].len);
149
150         } else for (i = 0; i < num; i++) { /* writing command */
151                 if (msgs[i].flags != 0 || msgs[i].buf == NULL || msgs[i].len < 2) {
152                         ret = -EINVAL;
153                         break;
154                 }
155
156                 ret = fc->i2c_request(fc, FC_WRITE, FC_I2C_PORT_DEMOD, msgs[i].addr, msgs[i].buf[0], &msgs[i].buf[1], msgs[i].len - 1);
157         }
158
159         if (ret < 0)
160                 err("i2c master_xfer failed");
161         else
162                 ret = num;
163
164         up(&fc->i2c_sem);
165
166         return ret;
167 }
168
169 static u32 flexcop_i2c_func(struct i2c_adapter *adapter)
170 {
171         return I2C_FUNC_I2C;
172 }
173
174 static struct i2c_algorithm flexcop_algo = {
175         .master_xfer    = flexcop_master_xfer,
176         .functionality  = flexcop_i2c_func,
177 };
178
179 int flexcop_i2c_init(struct flexcop_device *fc)
180 {
181         int ret;
182
183         sema_init(&fc->i2c_sem,1);
184
185         memset(&fc->i2c_adap, 0, sizeof(struct i2c_adapter));
186         strncpy(fc->i2c_adap.name, "B2C2 FlexCop device",I2C_NAME_SIZE);
187
188         i2c_set_adapdata(&fc->i2c_adap,fc);
189
190         fc->i2c_adap.class          = I2C_CLASS_TV_DIGITAL;
191         fc->i2c_adap.algo       = &flexcop_algo;
192         fc->i2c_adap.algo_data  = NULL;
193         fc->i2c_adap.id         = I2C_ALGO_BIT;
194
195         if ((ret = i2c_add_adapter(&fc->i2c_adap)) < 0)
196                 return ret;
197
198         fc->init_state |= FC_STATE_I2C_INIT;
199         return 0;
200 }
201
202 void flexcop_i2c_exit(struct flexcop_device *fc)
203 {
204         if (fc->init_state & FC_STATE_I2C_INIT)
205                 i2c_del_adapter(&fc->i2c_adap);
206
207         fc->init_state &= ~FC_STATE_I2C_INIT;
208 }