xref: /linux/drivers/media/common/b2c2/flexcop-i2c.c (revision bb9707077b4ee5f77bc9939b057ff8a0d410296f)
1 /*
2  * Linux driver for digital TV devices equipped with B2C2 FlexcopII(b)/III
3  * flexcop-i2c.c - flexcop internal 2Wire bus (I2C) and dvb i2c initialization
4  * see flexcop.c for copyright information
5  */
6 #include "flexcop.h"
7 
8 #define FC_MAX_I2C_RETRIES 100000
9 
10 static int flexcop_i2c_operation(struct flexcop_device *fc,
11 		flexcop_ibi_value *r100)
12 {
13 	int i;
14 	flexcop_ibi_value r;
15 
16 	r100->tw_sm_c_100.working_start = 1;
17 	deb_i2c("r100 before: %08x\n",r100->raw);
18 
19 	fc->write_ibi_reg(fc, tw_sm_c_100, ibi_zero);
20 	fc->write_ibi_reg(fc, tw_sm_c_100, *r100); /* initiating i2c operation */
21 
22 	for (i = 0; i < FC_MAX_I2C_RETRIES; i++) {
23 		r = fc->read_ibi_reg(fc, tw_sm_c_100);
24 
25 		if (!r.tw_sm_c_100.no_base_addr_ack_error) {
26 			if (r.tw_sm_c_100.st_done) {
27 				*r100 = r;
28 				deb_i2c("i2c success\n");
29 				return 0;
30 			}
31 		} else {
32 			deb_i2c("suffering from an i2c ack_error\n");
33 			return -EREMOTEIO;
34 		}
35 	}
36 	deb_i2c("tried %d times i2c operation, "
37 			"never finished or too many ack errors.\n", i);
38 	return -EREMOTEIO;
39 }
40 
41 static int flexcop_i2c_read4(struct flexcop_i2c_adapter *i2c,
42 		flexcop_ibi_value r100, u8 *buf)
43 {
44 	flexcop_ibi_value r104;
45 	int len = r100.tw_sm_c_100.total_bytes,
46 		/* remember total_bytes is buflen-1 */
47 		ret;
48 
49 	/* work-around to have CableStar2 and SkyStar2 rev 2.7 work
50 	 * correctly:
51 	 *
52 	 * the ITD1000 is behind an i2c-gate which closes automatically
53 	 * after an i2c-transaction the STV0297 needs 2 consecutive reads
54 	 * one with no_base_addr = 0 and one with 1
55 	 *
56 	 * those two work-arounds are conflictin: we check for the card
57 	 * type, it is set when probing the ITD1000 */
58 	if (i2c->fc->dev_type == FC_SKY_REV27)
59 		r100.tw_sm_c_100.no_base_addr_ack_error = i2c->no_base_addr;
60 
61 	ret = flexcop_i2c_operation(i2c->fc, &r100);
62 	if (ret != 0) {
63 		deb_i2c("Retrying operation\n");
64 		r100.tw_sm_c_100.no_base_addr_ack_error = i2c->no_base_addr;
65 		ret = flexcop_i2c_operation(i2c->fc, &r100);
66 	}
67 	if (ret != 0) {
68 		deb_i2c("read failed. %d\n", ret);
69 		return ret;
70 	}
71 
72 	buf[0] = r100.tw_sm_c_100.data1_reg;
73 
74 	if (len > 0) {
75 		r104 = i2c->fc->read_ibi_reg(i2c->fc, tw_sm_c_104);
76 		deb_i2c("read: r100: %08x, r104: %08x\n", r100.raw, r104.raw);
77 
78 		/* there is at least one more byte, otherwise we wouldn't be here */
79 		buf[1] = r104.tw_sm_c_104.data2_reg;
80 		if (len > 1) buf[2] = r104.tw_sm_c_104.data3_reg;
81 		if (len > 2) buf[3] = r104.tw_sm_c_104.data4_reg;
82 	}
83 	return 0;
84 }
85 
86 static int flexcop_i2c_write4(struct flexcop_device *fc,
87 		flexcop_ibi_value r100, u8 *buf)
88 {
89 	flexcop_ibi_value r104;
90 	int len = r100.tw_sm_c_100.total_bytes; /* remember total_bytes is buflen-1 */
91 	r104.raw = 0;
92 
93 	/* there is at least one byte, otherwise we wouldn't be here */
94 	r100.tw_sm_c_100.data1_reg = buf[0];
95 	r104.tw_sm_c_104.data2_reg = len > 0 ? buf[1] : 0;
96 	r104.tw_sm_c_104.data3_reg = len > 1 ? buf[2] : 0;
97 	r104.tw_sm_c_104.data4_reg = len > 2 ? buf[3] : 0;
98 
99 	deb_i2c("write: r100: %08x, r104: %08x\n", r100.raw, r104.raw);
100 
101 	/* write the additional i2c data before doing the actual i2c operation */
102 	fc->write_ibi_reg(fc, tw_sm_c_104, r104);
103 	return flexcop_i2c_operation(fc, &r100);
104 }
105 
106 int flexcop_i2c_request(struct flexcop_i2c_adapter *i2c,
107 		flexcop_access_op_t op, u8 chipaddr, u8 addr, u8 *buf, u16 len)
108 {
109 	int ret;
110 
111 #ifdef DUMP_I2C_MESSAGES
112 	int i;
113 #endif
114 
115 	u16 bytes_to_transfer;
116 	flexcop_ibi_value r100;
117 
118 	deb_i2c("op = %d\n",op);
119 	r100.raw = 0;
120 	r100.tw_sm_c_100.chipaddr = chipaddr;
121 	r100.tw_sm_c_100.twoWS_rw = op;
122 	r100.tw_sm_c_100.twoWS_port_reg = i2c->port;
123 
124 #ifdef DUMP_I2C_MESSAGES
125 	printk(KERN_DEBUG "%d ", i2c->port);
126 	if (op == FC_READ)
127 		printk("rd(");
128 	else
129 		printk("wr(");
130 	printk("%02x): %02x ", chipaddr, addr);
131 #endif
132 
133 	/* in that case addr is the only value ->
134 	 * we write it twice as baseaddr and val0
135 	 * BBTI is doing it like that for ISL6421 at least */
136 	if (i2c->no_base_addr && len == 0 && op == FC_WRITE) {
137 		buf = &addr;
138 		len = 1;
139 	}
140 
141 	while (len != 0) {
142 		bytes_to_transfer = len > 4 ? 4 : len;
143 
144 		r100.tw_sm_c_100.total_bytes = bytes_to_transfer - 1;
145 		r100.tw_sm_c_100.baseaddr = addr;
146 
147 		if (op == FC_READ)
148 			ret = flexcop_i2c_read4(i2c, r100, buf);
149 		else
150 			ret = flexcop_i2c_write4(i2c->fc, r100, buf);
151 
152 #ifdef DUMP_I2C_MESSAGES
153 		for (i = 0; i < bytes_to_transfer; i++)
154 			printk("%02x ", buf[i]);
155 #endif
156 
157 		if (ret < 0)
158 			return ret;
159 
160 		buf  += bytes_to_transfer;
161 		addr += bytes_to_transfer;
162 		len  -= bytes_to_transfer;
163 	}
164 
165 #ifdef DUMP_I2C_MESSAGES
166 	printk("\n");
167 #endif
168 
169 	return 0;
170 }
171 /* exported for PCI i2c */
172 EXPORT_SYMBOL(flexcop_i2c_request);
173 
174 /* master xfer callback for demodulator */
175 static int flexcop_master_xfer(struct i2c_adapter *i2c_adap,
176 		struct i2c_msg msgs[], int num)
177 {
178 	struct flexcop_i2c_adapter *i2c = i2c_get_adapdata(i2c_adap);
179 	int i, ret = 0;
180 
181 	/* Some drivers use 1 byte or 0 byte reads as probes, which this
182 	 * driver doesn't support.  These probes will always fail, so this
183 	 * hack makes them always succeed.  If one knew how, it would of
184 	 * course be better to actually do the read.  */
185 	if (num == 1 && msgs[0].flags == I2C_M_RD && msgs[0].len <= 1)
186 		return 1;
187 
188 	if (mutex_lock_interruptible(&i2c->fc->i2c_mutex))
189 		return -ERESTARTSYS;
190 
191 	for (i = 0; i < num; i++) {
192 		/* reading */
193 		if (i+1 < num && (msgs[i+1].flags == I2C_M_RD)) {
194 			ret = i2c->fc->i2c_request(i2c, FC_READ, msgs[i].addr,
195 					msgs[i].buf[0], msgs[i+1].buf,
196 					msgs[i+1].len);
197 			i++; /* skip the following message */
198 		} else /* writing */
199 			ret = i2c->fc->i2c_request(i2c, FC_WRITE, msgs[i].addr,
200 					msgs[i].buf[0], &msgs[i].buf[1],
201 					msgs[i].len - 1);
202 		if (ret < 0) {
203 			deb_i2c("i2c master_xfer failed");
204 			break;
205 		}
206 	}
207 
208 	mutex_unlock(&i2c->fc->i2c_mutex);
209 
210 	if (ret == 0)
211 		ret = num;
212 	return ret;
213 }
214 
215 static u32 flexcop_i2c_func(struct i2c_adapter *adapter)
216 {
217 	return I2C_FUNC_I2C;
218 }
219 
220 static struct i2c_algorithm flexcop_algo = {
221 	.master_xfer	= flexcop_master_xfer,
222 	.functionality	= flexcop_i2c_func,
223 };
224 
225 int flexcop_i2c_init(struct flexcop_device *fc)
226 {
227 	int ret;
228 	mutex_init(&fc->i2c_mutex);
229 
230 	fc->fc_i2c_adap[0].fc = fc;
231 	fc->fc_i2c_adap[1].fc = fc;
232 	fc->fc_i2c_adap[2].fc = fc;
233 	fc->fc_i2c_adap[0].port = FC_I2C_PORT_DEMOD;
234 	fc->fc_i2c_adap[1].port = FC_I2C_PORT_EEPROM;
235 	fc->fc_i2c_adap[2].port = FC_I2C_PORT_TUNER;
236 
237 	strlcpy(fc->fc_i2c_adap[0].i2c_adap.name, "B2C2 FlexCop I2C to demod",
238 			sizeof(fc->fc_i2c_adap[0].i2c_adap.name));
239 	strlcpy(fc->fc_i2c_adap[1].i2c_adap.name, "B2C2 FlexCop I2C to eeprom",
240 			sizeof(fc->fc_i2c_adap[1].i2c_adap.name));
241 	strlcpy(fc->fc_i2c_adap[2].i2c_adap.name, "B2C2 FlexCop I2C to tuner",
242 			sizeof(fc->fc_i2c_adap[2].i2c_adap.name));
243 
244 	i2c_set_adapdata(&fc->fc_i2c_adap[0].i2c_adap, &fc->fc_i2c_adap[0]);
245 	i2c_set_adapdata(&fc->fc_i2c_adap[1].i2c_adap, &fc->fc_i2c_adap[1]);
246 	i2c_set_adapdata(&fc->fc_i2c_adap[2].i2c_adap, &fc->fc_i2c_adap[2]);
247 
248 	fc->fc_i2c_adap[0].i2c_adap.algo =
249 		fc->fc_i2c_adap[1].i2c_adap.algo =
250 		fc->fc_i2c_adap[2].i2c_adap.algo = &flexcop_algo;
251 	fc->fc_i2c_adap[0].i2c_adap.algo_data =
252 		fc->fc_i2c_adap[1].i2c_adap.algo_data =
253 		fc->fc_i2c_adap[2].i2c_adap.algo_data = NULL;
254 	fc->fc_i2c_adap[0].i2c_adap.dev.parent =
255 		fc->fc_i2c_adap[1].i2c_adap.dev.parent =
256 		fc->fc_i2c_adap[2].i2c_adap.dev.parent = fc->dev;
257 
258 	ret = i2c_add_adapter(&fc->fc_i2c_adap[0].i2c_adap);
259 	if (ret < 0)
260 		return ret;
261 
262 	ret = i2c_add_adapter(&fc->fc_i2c_adap[1].i2c_adap);
263 	if (ret < 0)
264 		goto adap_1_failed;
265 
266 	ret = i2c_add_adapter(&fc->fc_i2c_adap[2].i2c_adap);
267 	if (ret < 0)
268 		goto adap_2_failed;
269 
270 	fc->init_state |= FC_STATE_I2C_INIT;
271 	return 0;
272 
273 adap_2_failed:
274 	i2c_del_adapter(&fc->fc_i2c_adap[1].i2c_adap);
275 adap_1_failed:
276 	i2c_del_adapter(&fc->fc_i2c_adap[0].i2c_adap);
277 	return ret;
278 }
279 
280 void flexcop_i2c_exit(struct flexcop_device *fc)
281 {
282 	if (fc->init_state & FC_STATE_I2C_INIT) {
283 		i2c_del_adapter(&fc->fc_i2c_adap[2].i2c_adap);
284 		i2c_del_adapter(&fc->fc_i2c_adap[1].i2c_adap);
285 		i2c_del_adapter(&fc->fc_i2c_adap[0].i2c_adap);
286 	}
287 	fc->init_state &= ~FC_STATE_I2C_INIT;
288 }
289