nv_i2c.c revision 3269711b76ba27b78862c48398b0d313ccaa99c2 
1/*
2 * linux/drivers/video/nvidia/nvidia-i2c.c - nVidia i2c
3 *
4 * Copyright 2004 Antonino A. Daplas <adaplas @pol.net>
5 *
6 * Based on rivafb-i2c.c
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License.  See the file COPYING in the main directory of this archive
10 * for more details.
11 */
12
13#include <linux/module.h>
14#include <linux/kernel.h>
15#include <linux/sched.h>
16#include <linux/delay.h>
17#include <linux/pci.h>
18#include <linux/fb.h>
19
20#include <asm/io.h>
21
22#include "nv_type.h"
23#include "nv_local.h"
24#include "nv_proto.h"
25
26#include "../edid.h"
27
28static void nvidia_gpio_setscl(void *data, int state)
29{
30	struct nvidia_i2c_chan *chan = data;
31	struct nvidia_par *par = chan->par;
32	u32 val;
33
34	VGA_WR08(par->PCIO, 0x3d4, chan->ddc_base + 1);
35	val = VGA_RD08(par->PCIO, 0x3d5) & 0xf0;
36
37	if (state)
38		val |= 0x20;
39	else
40		val &= ~0x20;
41
42	VGA_WR08(par->PCIO, 0x3d4, chan->ddc_base + 1);
43	VGA_WR08(par->PCIO, 0x3d5, val | 0x1);
44}
45
46static void nvidia_gpio_setsda(void *data, int state)
47{
48	struct nvidia_i2c_chan *chan = data;
49	struct nvidia_par *par = chan->par;
50	u32 val;
51
52	VGA_WR08(par->PCIO, 0x3d4, chan->ddc_base + 1);
53	val = VGA_RD08(par->PCIO, 0x3d5) & 0xf0;
54
55	if (state)
56		val |= 0x10;
57	else
58		val &= ~0x10;
59
60	VGA_WR08(par->PCIO, 0x3d4, chan->ddc_base + 1);
61	VGA_WR08(par->PCIO, 0x3d5, val | 0x1);
62}
63
64static int nvidia_gpio_getscl(void *data)
65{
66	struct nvidia_i2c_chan *chan = data;
67	struct nvidia_par *par = chan->par;
68	u32 val = 0;
69
70	VGA_WR08(par->PCIO, 0x3d4, chan->ddc_base);
71	if (VGA_RD08(par->PCIO, 0x3d5) & 0x04)
72		val = 1;
73
74	val = VGA_RD08(par->PCIO, 0x3d5);
75
76	return val;
77}
78
79static int nvidia_gpio_getsda(void *data)
80{
81	struct nvidia_i2c_chan *chan = data;
82	struct nvidia_par *par = chan->par;
83	u32 val = 0;
84
85	VGA_WR08(par->PCIO, 0x3d4, chan->ddc_base);
86	if (VGA_RD08(par->PCIO, 0x3d5) & 0x08)
87		val = 1;
88
89	return val;
90}
91
92static int nvidia_setup_i2c_bus(struct nvidia_i2c_chan *chan, const char *name)
93{
94	int rc;
95
96	strcpy(chan->adapter.name, name);
97	chan->adapter.owner = THIS_MODULE;
98	chan->adapter.id = I2C_HW_B_NVIDIA;
99	chan->adapter.algo_data = &chan->algo;
100	chan->adapter.dev.parent = &chan->par->pci_dev->dev;
101	chan->algo.setsda = nvidia_gpio_setsda;
102	chan->algo.setscl = nvidia_gpio_setscl;
103	chan->algo.getsda = nvidia_gpio_getsda;
104	chan->algo.getscl = nvidia_gpio_getscl;
105	chan->algo.udelay = 40;
106	chan->algo.timeout = msecs_to_jiffies(2);
107	chan->algo.data = chan;
108
109	i2c_set_adapdata(&chan->adapter, chan);
110
111	/* Raise SCL and SDA */
112	nvidia_gpio_setsda(chan, 1);
113	nvidia_gpio_setscl(chan, 1);
114	udelay(20);
115
116	rc = i2c_bit_add_bus(&chan->adapter);
117	if (rc == 0)
118		dev_dbg(&chan->par->pci_dev->dev,
119			"I2C bus %s registered.\n", name);
120	else {
121		dev_warn(&chan->par->pci_dev->dev,
122			 "Failed to register I2C bus %s.\n", name);
123		chan->par = NULL;
124	}
125
126	return rc;
127}
128
129void nvidia_create_i2c_busses(struct nvidia_par *par)
130{
131	par->bus = 3;
132
133	par->chan[0].par = par;
134	par->chan[1].par = par;
135	par->chan[2].par = par;
136
137	par->chan[0].ddc_base = 0x3e;
138	nvidia_setup_i2c_bus(&par->chan[0], "nvidia #0");
139
140	par->chan[1].ddc_base = 0x36;
141	nvidia_setup_i2c_bus(&par->chan[1], "nvidia #1");
142
143	par->chan[2].ddc_base = 0x50;
144	nvidia_setup_i2c_bus(&par->chan[2], "nvidia #2");
145}
146
147void nvidia_delete_i2c_busses(struct nvidia_par *par)
148{
149	if (par->chan[0].par)
150		i2c_del_adapter(&par->chan[0].adapter);
151	par->chan[0].par = NULL;
152
153	if (par->chan[1].par)
154		i2c_del_adapter(&par->chan[1].adapter);
155	par->chan[1].par = NULL;
156
157	if (par->chan[2].par)
158		i2c_del_adapter(&par->chan[2].adapter);
159	par->chan[2].par = NULL;
160
161}
162
163static u8 *nvidia_do_probe_i2c_edid(struct nvidia_i2c_chan *chan)
164{
165	u8 start = 0x0;
166	struct i2c_msg msgs[] = {
167		{
168		 .addr = 0x50,
169		 .len = 1,
170		 .buf = &start,
171		 }, {
172		     .addr = 0x50,
173		     .flags = I2C_M_RD,
174		     .len = EDID_LENGTH,
175		     },
176	};
177	u8 *buf;
178
179	if (!chan->par)
180		return NULL;
181
182	buf = kmalloc(EDID_LENGTH, GFP_KERNEL);
183	if (!buf) {
184		dev_warn(&chan->par->pci_dev->dev, "Out of memory!\n");
185		return NULL;
186	}
187	msgs[1].buf = buf;
188
189	if (i2c_transfer(&chan->adapter, msgs, 2) == 2)
190		return buf;
191	dev_dbg(&chan->par->pci_dev->dev, "Unable to read EDID block.\n");
192	kfree(buf);
193	return NULL;
194}
195
196int nvidia_probe_i2c_connector(struct fb_info *info, int conn, u8 **out_edid)
197{
198	struct nvidia_par *par = info->par;
199	u8 *edid = NULL;
200	int i;
201
202	for (i = 0; i < 3; i++) {
203		/* Do the real work */
204		edid = nvidia_do_probe_i2c_edid(&par->chan[conn - 1]);
205		if (edid)
206			break;
207	}
208
209	if (!edid && conn == 1) {
210		/* try to get from firmware */
211		const u8 *e = fb_firmware_edid(info->device);
212
213		if (e != NULL)
214			edid = kmemdup(e, EDID_LENGTH, GFP_KERNEL);
215	}
216
217	*out_edid = edid;
218
219	return (edid) ? 0 : 1;
220}
221