nv_i2c.c revision 2707cd016b12d5e64c4feefcb5740b65f0c46845 
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/delay.h>
16#include <linux/pci.h>
17#include <linux/fb.h>
18
19#include <asm/io.h>
20
21#include "nv_type.h"
22#include "nv_local.h"
23#include "nv_proto.h"
24
25#include "../edid.h"
26
27static void nvidia_gpio_setscl(void *data, int state)
28{
29	struct nvidia_i2c_chan *chan = data;
30	struct nvidia_par *par = chan->par;
31	u32 val;
32
33	VGA_WR08(par->PCIO, 0x3d4, chan->ddc_base + 1);
34	val = VGA_RD08(par->PCIO, 0x3d5) & 0xf0;
35
36	if (state)
37		val |= 0x20;
38	else
39		val &= ~0x20;
40
41	VGA_WR08(par->PCIO, 0x3d4, chan->ddc_base + 1);
42	VGA_WR08(par->PCIO, 0x3d5, val | 0x1);
43}
44
45static void nvidia_gpio_setsda(void *data, int state)
46{
47	struct nvidia_i2c_chan *chan = data;
48	struct nvidia_par *par = chan->par;
49	u32 val;
50
51	VGA_WR08(par->PCIO, 0x3d4, chan->ddc_base + 1);
52	val = VGA_RD08(par->PCIO, 0x3d5) & 0xf0;
53
54	if (state)
55		val |= 0x10;
56	else
57		val &= ~0x10;
58
59	VGA_WR08(par->PCIO, 0x3d4, chan->ddc_base + 1);
60	VGA_WR08(par->PCIO, 0x3d5, val | 0x1);
61}
62
63static int nvidia_gpio_getscl(void *data)
64{
65	struct nvidia_i2c_chan *chan = data;
66	struct nvidia_par *par = chan->par;
67	u32 val = 0;
68
69	VGA_WR08(par->PCIO, 0x3d4, chan->ddc_base);
70	if (VGA_RD08(par->PCIO, 0x3d5) & 0x04)
71		val = 1;
72
73	return val;
74}
75
76static int nvidia_gpio_getsda(void *data)
77{
78	struct nvidia_i2c_chan *chan = data;
79	struct nvidia_par *par = chan->par;
80	u32 val = 0;
81
82	VGA_WR08(par->PCIO, 0x3d4, chan->ddc_base);
83	if (VGA_RD08(par->PCIO, 0x3d5) & 0x08)
84		val = 1;
85
86	return val;
87}
88
89static int nvidia_setup_i2c_bus(struct nvidia_i2c_chan *chan, const char *name)
90{
91	int rc;
92
93	strcpy(chan->adapter.name, name);
94	chan->adapter.owner = THIS_MODULE;
95	chan->adapter.id = I2C_HW_B_NVIDIA;
96	chan->adapter.algo_data = &chan->algo;
97	chan->adapter.dev.parent = &chan->par->pci_dev->dev;
98	chan->algo.setsda = nvidia_gpio_setsda;
99	chan->algo.setscl = nvidia_gpio_setscl;
100	chan->algo.getsda = nvidia_gpio_getsda;
101	chan->algo.getscl = nvidia_gpio_getscl;
102	chan->algo.udelay = 40;
103	chan->algo.timeout = msecs_to_jiffies(2);
104	chan->algo.data = chan;
105
106	i2c_set_adapdata(&chan->adapter, chan);
107
108	/* Raise SCL and SDA */
109	nvidia_gpio_setsda(chan, 1);
110	nvidia_gpio_setscl(chan, 1);
111	udelay(20);
112
113	rc = i2c_bit_add_bus(&chan->adapter);
114	if (rc == 0)
115		dev_dbg(&chan->par->pci_dev->dev,
116			"I2C bus %s registered.\n", name);
117	else {
118		dev_warn(&chan->par->pci_dev->dev,
119			 "Failed to register I2C bus %s.\n", name);
120		chan->par = NULL;
121	}
122
123	return rc;
124}
125
126void nvidia_create_i2c_busses(struct nvidia_par *par)
127{
128	par->bus = 3;
129
130	par->chan[0].par = par;
131	par->chan[1].par = par;
132	par->chan[2].par = par;
133
134	par->chan[0].ddc_base = 0x36;
135	nvidia_setup_i2c_bus(&par->chan[0], "nvidia #0");
136
137	par->chan[1].ddc_base = 0x3e;
138	nvidia_setup_i2c_bus(&par->chan[1], "nvidia #1");
139
140	par->chan[2].ddc_base = 0x50;
141	nvidia_setup_i2c_bus(&par->chan[2], "nvidia #2");
142}
143
144void nvidia_delete_i2c_busses(struct nvidia_par *par)
145{
146	if (par->chan[0].par)
147		i2c_del_adapter(&par->chan[0].adapter);
148	par->chan[0].par = NULL;
149
150	if (par->chan[1].par)
151		i2c_del_adapter(&par->chan[1].adapter);
152	par->chan[1].par = NULL;
153
154	if (par->chan[2].par)
155		i2c_del_adapter(&par->chan[2].adapter);
156	par->chan[2].par = NULL;
157
158}
159
160int nvidia_probe_i2c_connector(struct fb_info *info, int conn, u8 **out_edid)
161{
162	struct nvidia_par *par = info->par;
163	u8 *edid = NULL;
164
165	if (par->chan[conn - 1].par)
166		edid = fb_ddc_read(&par->chan[conn - 1].adapter);
167
168	if (!edid && conn == 1) {
169		/* try to get from firmware */
170		const u8 *e = fb_firmware_edid(info->device);
171
172		if (e != NULL)
173			edid = kmemdup(e, EDID_LENGTH, GFP_KERNEL);
174	}
175
176	*out_edid = edid;
177
178	return (edid) ? 0 : 1;
179}
180