1/*
2 * linux/drivers/video/riva/fbdev-i2c.c - nVidia i2c
3 *
4 * Maintained by Ani Joshi <ajoshi@shell.unixbox.com>
5 *
6 * Copyright 2004 Antonino A. Daplas <adaplas @pol.net>
7 *
8 * Based on radeonfb-i2c.c
9 *
10 * This file is subject to the terms and conditions of the GNU General Public
11 * License. See the file COPYING in the main directory of this archive
12 * for more details.
13 */
14
15#include <linux/module.h>
16#include <linux/kernel.h>
17#include <linux/delay.h>
18#include <linux/pci.h>
19#include <linux/fb.h>
20#include <linux/jiffies.h>
21
22#include <asm/io.h>
23
24#include "rivafb.h"
25#include "../edid.h"
26
27static void riva_gpio_setscl(void* data, int state)
28{
29 struct riva_i2c_chan *chan = data;
30 struct riva_par *par = chan->par;
31 u32 val;
32
33 VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base + 1);
34 val = VGA_RD08(par->riva.PCIO, 0x3d5) & 0xf0;
35
36 if (state)
37 val |= 0x20;
38 else
39 val &= ~0x20;
40
41 VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base + 1);
42 VGA_WR08(par->riva.PCIO, 0x3d5, val | 0x1);
43}
44
45static void riva_gpio_setsda(void* data, int state)
46{
47 struct riva_i2c_chan *chan = data;
48 struct riva_par *par = chan->par;
49 u32 val;
50
51 VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base + 1);
52 val = VGA_RD08(par->riva.PCIO, 0x3d5) & 0xf0;
53
54 if (state)
55 val |= 0x10;
56 else
57 val &= ~0x10;
58
59 VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base + 1);
60 VGA_WR08(par->riva.PCIO, 0x3d5, val | 0x1);
61}
62
63static int riva_gpio_getscl(void* data)
64{
65 struct riva_i2c_chan *chan = data;
66 struct riva_par *par = chan->par;
67 u32 val = 0;
68
69 VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base);
70 if (VGA_RD08(par->riva.PCIO, 0x3d5) & 0x04)
71 val = 1;
72
73 return val;
74}
75
76static int riva_gpio_getsda(void* data)
77{
78 struct riva_i2c_chan *chan = data;
79 struct riva_par *par = chan->par;
80 u32 val = 0;
81
82 VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base);
83 if (VGA_RD08(par->riva.PCIO, 0x3d5) & 0x08)
84 val = 1;
85
86 return val;
87}
88
89static int riva_setup_i2c_bus(struct riva_i2c_chan *chan, const char *name,
90 unsigned int i2c_class)
91{
92 int rc;
93
94 strcpy(p: chan->adapter.name, q: name);
95 chan->adapter.owner = THIS_MODULE;
96 chan->adapter.class = i2c_class;
97 chan->adapter.algo_data = &chan->algo;
98 chan->adapter.dev.parent = &chan->par->pdev->dev;
99 chan->algo.setsda = riva_gpio_setsda;
100 chan->algo.setscl = riva_gpio_setscl;
101 chan->algo.getsda = riva_gpio_getsda;
102 chan->algo.getscl = riva_gpio_getscl;
103 chan->algo.udelay = 40;
104 chan->algo.timeout = msecs_to_jiffies(m: 2);
105 chan->algo.data = chan;
106
107 i2c_set_adapdata(adap: &chan->adapter, data: chan);
108
109 /* Raise SCL and SDA */
110 riva_gpio_setsda(data: chan, state: 1);
111 riva_gpio_setscl(data: chan, state: 1);
112 udelay(20);
113
114 rc = i2c_bit_add_bus(&chan->adapter);
115 if (rc == 0)
116 dev_dbg(&chan->par->pdev->dev, "I2C bus %s registered.\n", name);
117 else {
118 dev_warn(&chan->par->pdev->dev,
119 "Failed to register I2C bus %s.\n", name);
120 chan->par = NULL;
121 }
122
123 return rc;
124}
125
126void riva_create_i2c_busses(struct riva_par *par)
127{
128 par->chan[0].par = par;
129 par->chan[1].par = par;
130 par->chan[2].par = par;
131
132 par->chan[0].ddc_base = 0x36;
133 par->chan[1].ddc_base = 0x3e;
134 par->chan[2].ddc_base = 0x50;
135 riva_setup_i2c_bus(chan: &par->chan[0], name: "BUS1", I2C_CLASS_HWMON);
136 riva_setup_i2c_bus(chan: &par->chan[1], name: "BUS2", i2c_class: 0);
137 riva_setup_i2c_bus(chan: &par->chan[2], name: "BUS3", i2c_class: 0);
138}
139
140void riva_delete_i2c_busses(struct riva_par *par)
141{
142 int i;
143
144 for (i = 0; i < 3; i++) {
145 if (!par->chan[i].par)
146 continue;
147 i2c_del_adapter(adap: &par->chan[i].adapter);
148 par->chan[i].par = NULL;
149 }
150}
151
152int riva_probe_i2c_connector(struct riva_par *par, int conn, u8 **out_edid)
153{
154 u8 *edid = NULL;
155
156 if (par->chan[conn].par)
157 edid = fb_ddc_read(adapter: &par->chan[conn].adapter);
158
159 if (out_edid)
160 *out_edid = edid;
161 if (!edid)
162 return 1;
163
164 return 0;
165}
166
167

source code of linux/drivers/video/fbdev/riva/rivafb-i2c.c