xref: /linux/drivers/media/pci/mantis/mantis_i2c.c (revision 93d90ad708b8da6efc0e487b66111aa9db7f70c7)
1 /*
2 	Mantis PCI bridge driver
3 
4 	Copyright (C) Manu Abraham (abraham.manu@gmail.com)
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 as published by
8 	the Free Software Foundation; either version 2 of the License, or
9 	(at your option) any later version.
10 
11 	This program is distributed in the hope that it will be useful,
12 	but WITHOUT ANY WARRANTY; without even the implied warranty of
13 	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 	GNU General Public License for more details.
15 
16 	You should have received a copy of the GNU General Public License
17 	along with this program; if not, write to the Free Software
18 	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20 
21 #include <asm/io.h>
22 #include <linux/ioport.h>
23 #include <linux/pci.h>
24 #include <linux/i2c.h>
25 
26 #include "dmxdev.h"
27 #include "dvbdev.h"
28 #include "dvb_demux.h"
29 #include "dvb_frontend.h"
30 #include "dvb_net.h"
31 
32 #include "mantis_common.h"
33 #include "mantis_reg.h"
34 #include "mantis_i2c.h"
35 
36 #define TRIALS			10000
37 
38 static int mantis_i2c_read(struct mantis_pci *mantis, const struct i2c_msg *msg)
39 {
40 	u32 rxd, i, stat, trials;
41 
42 	dprintk(MANTIS_INFO, 0, "        %s:  Address=[0x%02x] <R>[ ",
43 		__func__, msg->addr);
44 
45 	for (i = 0; i < msg->len; i++) {
46 		rxd = (msg->addr << 25) | (1 << 24)
47 					| MANTIS_I2C_RATE_3
48 					| MANTIS_I2C_STOP
49 					| MANTIS_I2C_PGMODE;
50 
51 		if (i == (msg->len - 1))
52 			rxd &= ~MANTIS_I2C_STOP;
53 
54 		mmwrite(MANTIS_INT_I2CDONE, MANTIS_INT_STAT);
55 		mmwrite(rxd, MANTIS_I2CDATA_CTL);
56 
57 		/* wait for xfer completion */
58 		for (trials = 0; trials < TRIALS; trials++) {
59 			stat = mmread(MANTIS_INT_STAT);
60 			if (stat & MANTIS_INT_I2CDONE)
61 				break;
62 		}
63 
64 		dprintk(MANTIS_TMG, 0, "I2CDONE: trials=%d\n", trials);
65 
66 		/* wait for xfer completion */
67 		for (trials = 0; trials < TRIALS; trials++) {
68 			stat = mmread(MANTIS_INT_STAT);
69 			if (stat & MANTIS_INT_I2CRACK)
70 				break;
71 		}
72 
73 		dprintk(MANTIS_TMG, 0, "I2CRACK: trials=%d\n", trials);
74 
75 		rxd = mmread(MANTIS_I2CDATA_CTL);
76 		msg->buf[i] = (u8)((rxd >> 8) & 0xFF);
77 		dprintk(MANTIS_INFO, 0, "%02x ", msg->buf[i]);
78 	}
79 	dprintk(MANTIS_INFO, 0, "]\n");
80 
81 	return 0;
82 }
83 
84 static int mantis_i2c_write(struct mantis_pci *mantis, const struct i2c_msg *msg)
85 {
86 	int i;
87 	u32 txd = 0, stat, trials;
88 
89 	dprintk(MANTIS_INFO, 0, "        %s: Address=[0x%02x] <W>[ ",
90 		__func__, msg->addr);
91 
92 	for (i = 0; i < msg->len; i++) {
93 		dprintk(MANTIS_INFO, 0, "%02x ", msg->buf[i]);
94 		txd = (msg->addr << 25) | (msg->buf[i] << 8)
95 					| MANTIS_I2C_RATE_3
96 					| MANTIS_I2C_STOP
97 					| MANTIS_I2C_PGMODE;
98 
99 		if (i == (msg->len - 1))
100 			txd &= ~MANTIS_I2C_STOP;
101 
102 		mmwrite(MANTIS_INT_I2CDONE, MANTIS_INT_STAT);
103 		mmwrite(txd, MANTIS_I2CDATA_CTL);
104 
105 		/* wait for xfer completion */
106 		for (trials = 0; trials < TRIALS; trials++) {
107 			stat = mmread(MANTIS_INT_STAT);
108 			if (stat & MANTIS_INT_I2CDONE)
109 				break;
110 		}
111 
112 		dprintk(MANTIS_TMG, 0, "I2CDONE: trials=%d\n", trials);
113 
114 		/* wait for xfer completion */
115 		for (trials = 0; trials < TRIALS; trials++) {
116 			stat = mmread(MANTIS_INT_STAT);
117 			if (stat & MANTIS_INT_I2CRACK)
118 				break;
119 		}
120 
121 		dprintk(MANTIS_TMG, 0, "I2CRACK: trials=%d\n", trials);
122 	}
123 	dprintk(MANTIS_INFO, 0, "]\n");
124 
125 	return 0;
126 }
127 
128 static int mantis_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num)
129 {
130 	int ret = 0, i = 0, trials;
131 	u32 stat, data, txd;
132 	struct mantis_pci *mantis;
133 	struct mantis_hwconfig *config;
134 
135 	mantis = i2c_get_adapdata(adapter);
136 	BUG_ON(!mantis);
137 	config = mantis->hwconfig;
138 	BUG_ON(!config);
139 
140 	dprintk(MANTIS_DEBUG, 1, "Messages:%d", num);
141 	mutex_lock(&mantis->i2c_lock);
142 
143 	while (i < num) {
144 		/* Byte MODE */
145 		if ((config->i2c_mode & MANTIS_BYTE_MODE) &&
146 		    ((i + 1) < num)			&&
147 		    (msgs[i].len < 2)			&&
148 		    (msgs[i + 1].len < 2)		&&
149 		    (msgs[i + 1].flags & I2C_M_RD)) {
150 
151 			dprintk(MANTIS_DEBUG, 0, "        Byte MODE:\n");
152 
153 			/* Read operation */
154 			txd = msgs[i].addr << 25 | (0x1 << 24)
155 						 | (msgs[i].buf[0] << 16)
156 						 | MANTIS_I2C_RATE_3;
157 
158 			mmwrite(txd, MANTIS_I2CDATA_CTL);
159 			/* wait for xfer completion */
160 			for (trials = 0; trials < TRIALS; trials++) {
161 				stat = mmread(MANTIS_INT_STAT);
162 				if (stat & MANTIS_INT_I2CDONE)
163 					break;
164 			}
165 
166 			/* check for xfer completion */
167 			if (stat & MANTIS_INT_I2CDONE) {
168 				/* check xfer was acknowledged */
169 				if (stat & MANTIS_INT_I2CRACK) {
170 					data = mmread(MANTIS_I2CDATA_CTL);
171 					msgs[i + 1].buf[0] = (data >> 8) & 0xff;
172 					dprintk(MANTIS_DEBUG, 0, "        Byte <%d> RXD=0x%02x  [%02x]\n", 0x0, data, msgs[i + 1].buf[0]);
173 				} else {
174 					/* I/O error */
175 					dprintk(MANTIS_ERROR, 1, "        I/O error, LINE:%d", __LINE__);
176 					ret = -EIO;
177 					break;
178 				}
179 			} else {
180 				/* I/O error */
181 				dprintk(MANTIS_ERROR, 1, "        I/O error, LINE:%d", __LINE__);
182 				ret = -EIO;
183 				break;
184 			}
185 			i += 2; /* Write/Read operation in one go */
186 		}
187 
188 		if (i < num) {
189 			if (msgs[i].flags & I2C_M_RD)
190 				ret = mantis_i2c_read(mantis, &msgs[i]);
191 			else
192 				ret = mantis_i2c_write(mantis, &msgs[i]);
193 
194 			i++;
195 			if (ret < 0)
196 				goto bail_out;
197 		}
198 
199 	}
200 
201 	mutex_unlock(&mantis->i2c_lock);
202 
203 	return num;
204 
205 bail_out:
206 	mutex_unlock(&mantis->i2c_lock);
207 	return ret;
208 }
209 
210 static u32 mantis_i2c_func(struct i2c_adapter *adapter)
211 {
212 	return I2C_FUNC_SMBUS_EMUL;
213 }
214 
215 static struct i2c_algorithm mantis_algo = {
216 	.master_xfer		= mantis_i2c_xfer,
217 	.functionality		= mantis_i2c_func,
218 };
219 
220 int mantis_i2c_init(struct mantis_pci *mantis)
221 {
222 	u32 intstat, intmask;
223 	struct i2c_adapter *i2c_adapter = &mantis->adapter;
224 	struct pci_dev *pdev		= mantis->pdev;
225 
226 	init_waitqueue_head(&mantis->i2c_wq);
227 	mutex_init(&mantis->i2c_lock);
228 	strncpy(i2c_adapter->name, "Mantis I2C", sizeof(i2c_adapter->name));
229 	i2c_set_adapdata(i2c_adapter, mantis);
230 
231 	i2c_adapter->owner	= THIS_MODULE;
232 	i2c_adapter->algo	= &mantis_algo;
233 	i2c_adapter->algo_data	= NULL;
234 	i2c_adapter->timeout	= 500;
235 	i2c_adapter->retries	= 3;
236 	i2c_adapter->dev.parent	= &pdev->dev;
237 
238 	mantis->i2c_rc		= i2c_add_adapter(i2c_adapter);
239 	if (mantis->i2c_rc < 0)
240 		return mantis->i2c_rc;
241 
242 	dprintk(MANTIS_DEBUG, 1, "Initializing I2C ..");
243 
244 	intstat = mmread(MANTIS_INT_STAT);
245 	intmask = mmread(MANTIS_INT_MASK);
246 	mmwrite(intstat, MANTIS_INT_STAT);
247 	dprintk(MANTIS_DEBUG, 1, "Disabling I2C interrupt");
248 	intmask = mmread(MANTIS_INT_MASK);
249 	mmwrite((intmask & ~MANTIS_INT_I2CDONE), MANTIS_INT_MASK);
250 
251 	return 0;
252 }
253 EXPORT_SYMBOL_GPL(mantis_i2c_init);
254 
255 int mantis_i2c_exit(struct mantis_pci *mantis)
256 {
257 	u32 intmask;
258 
259 	dprintk(MANTIS_DEBUG, 1, "Disabling I2C interrupt");
260 	intmask = mmread(MANTIS_INT_MASK);
261 	mmwrite((intmask & ~MANTIS_INT_I2CDONE), MANTIS_INT_MASK);
262 
263 	dprintk(MANTIS_DEBUG, 1, "Removing I2C adapter");
264 	i2c_del_adapter(&mantis->adapter);
265 
266 	return 0;
267 }
268 EXPORT_SYMBOL_GPL(mantis_i2c_exit);
269