xref: /openbmc/linux/drivers/video/fbdev/via/via_i2c.c (revision 293d5b43)
1 /*
2  * Copyright 1998-2009 VIA Technologies, Inc. All Rights Reserved.
3  * Copyright 2001-2008 S3 Graphics, Inc. All Rights Reserved.
4 
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public
7  * License as published by the Free Software Foundation;
8  * either version 2, or (at your option) any later version.
9 
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTIES OR REPRESENTATIONS; without even
12  * the implied warranty of MERCHANTABILITY or FITNESS FOR
13  * A PARTICULAR PURPOSE.See the GNU General Public License
14  * 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.,
19  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20  */
21 
22 #include <linux/platform_device.h>
23 #include <linux/delay.h>
24 #include <linux/spinlock.h>
25 #include <linux/module.h>
26 #include <linux/via-core.h>
27 #include <linux/via_i2c.h>
28 
29 /*
30  * There can only be one set of these, so there's no point in having
31  * them be dynamically allocated...
32  */
33 #define VIAFB_NUM_I2C		5
34 static struct via_i2c_stuff via_i2c_par[VIAFB_NUM_I2C];
35 static struct viafb_dev *i2c_vdev;  /* Passed in from core */
36 
37 static void via_i2c_setscl(void *data, int state)
38 {
39 	u8 val;
40 	struct via_port_cfg *adap_data = data;
41 	unsigned long flags;
42 
43 	spin_lock_irqsave(&i2c_vdev->reg_lock, flags);
44 	val = via_read_reg(adap_data->io_port, adap_data->ioport_index) & 0xF0;
45 	if (state)
46 		val |= 0x20;
47 	else
48 		val &= ~0x20;
49 	switch (adap_data->type) {
50 	case VIA_PORT_I2C:
51 		val |= 0x01;
52 		break;
53 	case VIA_PORT_GPIO:
54 		val |= 0x82;
55 		break;
56 	default:
57 		printk(KERN_ERR "viafb_i2c: specify wrong i2c type.\n");
58 	}
59 	via_write_reg(adap_data->io_port, adap_data->ioport_index, val);
60 	spin_unlock_irqrestore(&i2c_vdev->reg_lock, flags);
61 }
62 
63 static int via_i2c_getscl(void *data)
64 {
65 	struct via_port_cfg *adap_data = data;
66 	unsigned long flags;
67 	int ret = 0;
68 
69 	spin_lock_irqsave(&i2c_vdev->reg_lock, flags);
70 	if (adap_data->type == VIA_PORT_GPIO)
71 		via_write_reg_mask(adap_data->io_port, adap_data->ioport_index,
72 			0, 0x80);
73 	if (via_read_reg(adap_data->io_port, adap_data->ioport_index) & 0x08)
74 		ret = 1;
75 	spin_unlock_irqrestore(&i2c_vdev->reg_lock, flags);
76 	return ret;
77 }
78 
79 static int via_i2c_getsda(void *data)
80 {
81 	struct via_port_cfg *adap_data = data;
82 	unsigned long flags;
83 	int ret = 0;
84 
85 	spin_lock_irqsave(&i2c_vdev->reg_lock, flags);
86 	if (adap_data->type == VIA_PORT_GPIO)
87 		via_write_reg_mask(adap_data->io_port, adap_data->ioport_index,
88 			0, 0x40);
89 	if (via_read_reg(adap_data->io_port, adap_data->ioport_index) & 0x04)
90 		ret = 1;
91 	spin_unlock_irqrestore(&i2c_vdev->reg_lock, flags);
92 	return ret;
93 }
94 
95 static void via_i2c_setsda(void *data, int state)
96 {
97 	u8 val;
98 	struct via_port_cfg *adap_data = data;
99 	unsigned long flags;
100 
101 	spin_lock_irqsave(&i2c_vdev->reg_lock, flags);
102 	val = via_read_reg(adap_data->io_port, adap_data->ioport_index) & 0xF0;
103 	if (state)
104 		val |= 0x10;
105 	else
106 		val &= ~0x10;
107 	switch (adap_data->type) {
108 	case VIA_PORT_I2C:
109 		val |= 0x01;
110 		break;
111 	case VIA_PORT_GPIO:
112 		val |= 0x42;
113 		break;
114 	default:
115 		printk(KERN_ERR "viafb_i2c: specify wrong i2c type.\n");
116 	}
117 	via_write_reg(adap_data->io_port, adap_data->ioport_index, val);
118 	spin_unlock_irqrestore(&i2c_vdev->reg_lock, flags);
119 }
120 
121 int viafb_i2c_readbyte(u8 adap, u8 slave_addr, u8 index, u8 *pdata)
122 {
123 	int ret;
124 	u8 mm1[] = {0x00};
125 	struct i2c_msg msgs[2];
126 
127 	if (!via_i2c_par[adap].is_active)
128 		return -ENODEV;
129 	*pdata = 0;
130 	msgs[0].flags = 0;
131 	msgs[1].flags = I2C_M_RD;
132 	msgs[0].addr = msgs[1].addr = slave_addr / 2;
133 	mm1[0] = index;
134 	msgs[0].len = 1; msgs[1].len = 1;
135 	msgs[0].buf = mm1; msgs[1].buf = pdata;
136 	ret = i2c_transfer(&via_i2c_par[adap].adapter, msgs, 2);
137 	if (ret == 2)
138 		ret = 0;
139 	else if (ret >= 0)
140 		ret = -EIO;
141 
142 	return ret;
143 }
144 
145 int viafb_i2c_writebyte(u8 adap, u8 slave_addr, u8 index, u8 data)
146 {
147 	int ret;
148 	u8 msg[2] = { index, data };
149 	struct i2c_msg msgs;
150 
151 	if (!via_i2c_par[adap].is_active)
152 		return -ENODEV;
153 	msgs.flags = 0;
154 	msgs.addr = slave_addr / 2;
155 	msgs.len = 2;
156 	msgs.buf = msg;
157 	ret = i2c_transfer(&via_i2c_par[adap].adapter, &msgs, 1);
158 	if (ret == 1)
159 		ret = 0;
160 	else if (ret >= 0)
161 		ret = -EIO;
162 
163 	return ret;
164 }
165 
166 int viafb_i2c_readbytes(u8 adap, u8 slave_addr, u8 index, u8 *buff, int buff_len)
167 {
168 	int ret;
169 	u8 mm1[] = {0x00};
170 	struct i2c_msg msgs[2];
171 
172 	if (!via_i2c_par[adap].is_active)
173 		return -ENODEV;
174 	msgs[0].flags = 0;
175 	msgs[1].flags = I2C_M_RD;
176 	msgs[0].addr = msgs[1].addr = slave_addr / 2;
177 	mm1[0] = index;
178 	msgs[0].len = 1; msgs[1].len = buff_len;
179 	msgs[0].buf = mm1; msgs[1].buf = buff;
180 	ret = i2c_transfer(&via_i2c_par[adap].adapter, msgs, 2);
181 	if (ret == 2)
182 		ret = 0;
183 	else if (ret >= 0)
184 		ret = -EIO;
185 
186 	return ret;
187 }
188 
189 /*
190  * Allow other viafb subdevices to look up a specific adapter
191  * by port name.
192  */
193 struct i2c_adapter *viafb_find_i2c_adapter(enum viafb_i2c_adap which)
194 {
195 	struct via_i2c_stuff *stuff = &via_i2c_par[which];
196 
197 	return &stuff->adapter;
198 }
199 EXPORT_SYMBOL_GPL(viafb_find_i2c_adapter);
200 
201 
202 static int create_i2c_bus(struct i2c_adapter *adapter,
203 			  struct i2c_algo_bit_data *algo,
204 			  struct via_port_cfg *adap_cfg,
205 			  struct pci_dev *pdev)
206 {
207 	algo->setsda = via_i2c_setsda;
208 	algo->setscl = via_i2c_setscl;
209 	algo->getsda = via_i2c_getsda;
210 	algo->getscl = via_i2c_getscl;
211 	algo->udelay = 10;
212 	algo->timeout = 2;
213 	algo->data = adap_cfg;
214 
215 	sprintf(adapter->name, "viafb i2c io_port idx 0x%02x",
216 		adap_cfg->ioport_index);
217 	adapter->owner = THIS_MODULE;
218 	adapter->class = I2C_CLASS_DDC;
219 	adapter->algo_data = algo;
220 	if (pdev)
221 		adapter->dev.parent = &pdev->dev;
222 	else
223 		adapter->dev.parent = NULL;
224 	/* i2c_set_adapdata(adapter, adap_cfg); */
225 
226 	/* Raise SCL and SDA */
227 	via_i2c_setsda(adap_cfg, 1);
228 	via_i2c_setscl(adap_cfg, 1);
229 	udelay(20);
230 
231 	return i2c_bit_add_bus(adapter);
232 }
233 
234 static int viafb_i2c_probe(struct platform_device *platdev)
235 {
236 	int i, ret;
237 	struct via_port_cfg *configs;
238 
239 	i2c_vdev = platdev->dev.platform_data;
240 	configs = i2c_vdev->port_cfg;
241 
242 	for (i = 0; i < VIAFB_NUM_PORTS; i++) {
243 		struct via_port_cfg *adap_cfg = configs++;
244 		struct via_i2c_stuff *i2c_stuff = &via_i2c_par[i];
245 
246 		i2c_stuff->is_active = 0;
247 		if (adap_cfg->type == 0 || adap_cfg->mode != VIA_MODE_I2C)
248 			continue;
249 		ret = create_i2c_bus(&i2c_stuff->adapter,
250 				     &i2c_stuff->algo, adap_cfg,
251 				NULL); /* FIXME: PCIDEV */
252 		if (ret < 0) {
253 			printk(KERN_ERR "viafb: cannot create i2c bus %u:%d\n",
254 				i, ret);
255 			continue;  /* Still try to make the rest */
256 		}
257 		i2c_stuff->is_active = 1;
258 	}
259 
260 	return 0;
261 }
262 
263 static int viafb_i2c_remove(struct platform_device *platdev)
264 {
265 	int i;
266 
267 	for (i = 0; i < VIAFB_NUM_PORTS; i++) {
268 		struct via_i2c_stuff *i2c_stuff = &via_i2c_par[i];
269 		/*
270 		 * Only remove those entries in the array that we've
271 		 * actually used (and thus initialized algo_data)
272 		 */
273 		if (i2c_stuff->is_active)
274 			i2c_del_adapter(&i2c_stuff->adapter);
275 	}
276 	return 0;
277 }
278 
279 static struct platform_driver via_i2c_driver = {
280 	.driver = {
281 		.name = "viafb-i2c",
282 	},
283 	.probe = viafb_i2c_probe,
284 	.remove = viafb_i2c_remove,
285 };
286 
287 int viafb_i2c_init(void)
288 {
289 	return platform_driver_register(&via_i2c_driver);
290 }
291 
292 void viafb_i2c_exit(void)
293 {
294 	platform_driver_unregister(&via_i2c_driver);
295 }
296