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 
27 static 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 
45 static 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 
63 static 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 
76 static 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 
89 static 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(chan->adapter.name, 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(2);
105 	chan->algo.data 		= chan;
106 
107 	i2c_set_adapdata(&chan->adapter, chan);
108 
109 	/* Raise SCL and SDA */
110 	riva_gpio_setsda(chan, 1);
111 	riva_gpio_setscl(chan, 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 
126 void 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(&par->chan[0], "BUS1", I2C_CLASS_HWMON);
136 	riva_setup_i2c_bus(&par->chan[1], "BUS2", 0);
137 	riva_setup_i2c_bus(&par->chan[2], "BUS3", 0);
138 }
139 
140 void 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(&par->chan[i].adapter);
148 		par->chan[i].par = NULL;
149 	}
150 }
151 
152 int 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(&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