aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/media/dvb/b2c2/flexcop-i2c.c
blob: 5347a406fff7e0e73abe885eff3562ca747a10a6 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
/*
 * This file is part of linux driver the digital TV devices equipped with B2C2 FlexcopII(b)/III
 *
 * flexcop-i2c.c - flexcop internal 2Wire bus (I2C) and dvb i2c initialization
 *
 * see flexcop.c for copyright information.
 */
#include "flexcop.h"

#define FC_MAX_I2C_RETRIES 100000

static int flexcop_i2c_operation(struct flexcop_device *fc, flexcop_ibi_value *r100)
{
	int i;
	flexcop_ibi_value r;

	r100->tw_sm_c_100.working_start = 1;
	deb_i2c("r100 before: %08x\n",r100->raw);

	fc->write_ibi_reg(fc, tw_sm_c_100, ibi_zero);
	fc->write_ibi_reg(fc, tw_sm_c_100, *r100); /* initiating i2c operation */

	for (i = 0; i < FC_MAX_I2C_RETRIES; i++) {
		r = fc->read_ibi_reg(fc, tw_sm_c_100);

		if (!r.tw_sm_c_100.no_base_addr_ack_error) {
			if (r.tw_sm_c_100.st_done) {  /* && !r.tw_sm_c_100.working_start */
				*r100 = r;
				deb_i2c("i2c success\n");
				return 0;
			}
		} else {
			deb_i2c("suffering from an i2c ack_error\n");
			return -EREMOTEIO;
		}
	}
	deb_i2c("tried %d times i2c operation, never finished or too many ack errors.\n",i);
	return -EREMOTEIO;
}

static int flexcop_i2c_read4(struct flexcop_device *fc, flexcop_ibi_value r100, u8 *buf)
{
	flexcop_ibi_value r104;
	int len = r100.tw_sm_c_100.total_bytes, /* remember total_bytes is buflen-1 */
		ret;

	if ((ret = flexcop_i2c_operation(fc,&r100)) != 0) {
		/* The Cablestar needs a different kind of i2c-transfer (does not
		 * support "Repeat Start"):
		 * wait for the ACK failure,
		 * and do a subsequent read with the Bit 30 enabled
		 */
		r100.tw_sm_c_100.no_base_addr_ack_error = 1;
		if ((ret = flexcop_i2c_operation(fc,&r100)) != 0) {
			deb_i2c("no_base_addr read failed. %d\n",ret);
			return ret;
		}
	}

	buf[0] = r100.tw_sm_c_100.data1_reg;

	if (len > 0) {
		r104 = fc->read_ibi_reg(fc,tw_sm_c_104);
		deb_i2c("read: r100: %08x, r104: %08x\n",r100.raw,r104.raw);

		/* there is at least one more byte, otherwise we wouldn't be here */
		buf[1] = r104.tw_sm_c_104.data2_reg;
		if (len > 1) buf[2] = r104.tw_sm_c_104.data3_reg;
		if (len > 2) buf[3] = r104.tw_sm_c_104.data4_reg;
	}

	return 0;
}

static int flexcop_i2c_write4(struct flexcop_device *fc, flexcop_ibi_value r100, u8 *buf)
{
	flexcop_ibi_value r104;
	int len = r100.tw_sm_c_100.total_bytes; /* remember total_bytes is buflen-1 */
	r104.raw = 0;

	/* there is at least one byte, otherwise we wouldn't be here */
	r100.tw_sm_c_100.data1_reg = buf[0];

	r104.tw_sm_c_104.data2_reg = len > 0 ? buf[1] : 0;
	r104.tw_sm_c_104.data3_reg = len > 1 ? buf[2] : 0;
	r104.tw_sm_c_104.data4_reg = len > 2 ? buf[3] : 0;

	deb_i2c("write: r100: %08x, r104: %08x\n",r100.raw,r104.raw);

	/* write the additional i2c data before doing the actual i2c operation */
	fc->write_ibi_reg(fc,tw_sm_c_104,r104);
	return flexcop_i2c_operation(fc,&r100);
}

int flexcop_i2c_request(struct flexcop_device *fc, flexcop_access_op_t op,
		flexcop_i2c_port_t port, u8 chipaddr, u8 addr, u8 *buf, u16 len)
{
	int ret;
	u16 bytes_to_transfer;
	flexcop_ibi_value r100;

	deb_i2c("op = %d\n",op);
	r100.raw = 0;
	r100.tw_sm_c_100.chipaddr = chipaddr;
	r100.tw_sm_c_100.twoWS_rw = op;
	r100.tw_sm_c_100.twoWS_port_reg = port;

	while (len != 0) {
		bytes_to_transfer = len > 4 ? 4 : len;

		r100.tw_sm_c_100.total_bytes = bytes_to_transfer - 1;
		r100.tw_sm_c_100.baseaddr = addr;

		if (op == FC_READ)
			ret = flexcop_i2c_read4(fc, r100, buf);
		else
			ret = flexcop_i2c_write4(fc,r100, buf);

		if (ret < 0)
			return ret;

		buf  += bytes_to_transfer;
		addr += bytes_to_transfer;
		len  -= bytes_to_transfer;
	};

	return 0;
}
/* exported for PCI i2c */
EXPORT_SYMBOL(flexcop_i2c_request);

/* master xfer callback for demodulator */
static int flexcop_master_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num)
{
	struct flexcop_device *fc = i2c_get_adapdata(i2c_adap);
	int i, ret = 0;

	if (mutex_lock_interruptible(&fc->i2c_mutex))
		return -ERESTARTSYS;

	/* reading */
	if (num == 2 &&
		msgs[0].flags == 0 &&
		msgs[1].flags == I2C_M_RD &&
		msgs[0].buf != NULL &&
		msgs[1].buf != NULL) {

		ret = fc->i2c_request(fc, FC_READ, FC_I2C_PORT_DEMOD, msgs[0].addr, msgs[0].buf[0], msgs[1].buf, msgs[1].len);

	} else for (i = 0; i < num; i++) { /* writing command */
		if (msgs[i].flags != 0 || msgs[i].buf == NULL || msgs[i].len < 2) {
			ret = -EINVAL;
			break;
		}

		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);
	}

	if (ret < 0)
		err("i2c master_xfer failed");
	else
		ret = num;

	mutex_unlock(&fc->i2c_mutex);

	return ret;
}

static u32 flexcop_i2c_func(struct i2c_adapter *adapter)
{
	return I2C_FUNC_I2C;
}

static struct i2c_algorithm flexcop_algo = {
	.master_xfer	= flexcop_master_xfer,
	.functionality	= flexcop_i2c_func,
};

int flexcop_i2c_init(struct flexcop_device *fc)
{
	int ret;

	mutex_init(&fc->i2c_mutex);

	memset(&fc->i2c_adap, 0, sizeof(struct i2c_adapter));
	strncpy(fc->i2c_adap.name, "B2C2 FlexCop device",I2C_NAME_SIZE);

	i2c_set_adapdata(&fc->i2c_adap,fc);

	fc->i2c_adap.class	    = I2C_CLASS_TV_DIGITAL;
	fc->i2c_adap.algo       = &flexcop_algo;
	fc->i2c_adap.algo_data  = NULL;
	fc->i2c_adap.dev.parent	= fc->dev;

	if ((ret = i2c_add_adapter(&fc->i2c_adap)) < 0)
		return ret;

	fc->init_state |= FC_STATE_I2C_INIT;
	return 0;
}

void flexcop_i2c_exit(struct flexcop_device *fc)
{
	if (fc->init_state & FC_STATE_I2C_INIT)
		i2c_del_adapter(&fc->i2c_adap);

	fc->init_state &= ~FC_STATE_I2C_INIT;
}