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
10static 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
41static 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
86static 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
106int 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 */
172EXPORT_SYMBOL(flexcop_i2c_request);
173
174/* master xfer callback for demodulator */
175static 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
215static u32 flexcop_i2c_func(struct i2c_adapter *adapter)
216{
217	return I2C_FUNC_I2C;
218}
219
220static struct i2c_algorithm flexcop_algo = {
221	.master_xfer	= flexcop_master_xfer,
222	.functionality	= flexcop_i2c_func,
223};
224
225int 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
273adap_2_failed:
274	i2c_del_adapter(&fc->fc_i2c_adap[1].i2c_adap);
275adap_1_failed:
276	i2c_del_adapter(&fc->fc_i2c_adap[0].i2c_adap);
277	return ret;
278}
279
280void 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