1 /*-*- linux-c -*-
2 *  linux/drivers/video/i810-i2c.c -- Intel 810/815 I2C support
3 *
4 *      Copyright (C) 2004 Antonino Daplas<adaplas@pol.net>
5 *      All Rights Reserved
6 *
7 *  This file is subject to the terms and conditions of the GNU General Public
8 *  License. See the file COPYING in the main directory of this archive for
9 *  more details.
10 */
11#include <linux/module.h>
12#include <linux/kernel.h>
13#include <linux/delay.h>
14#include <linux/gfp.h>
15#include <linux/pci.h>
16#include <linux/fb.h>
17#include "i810.h"
18#include "i810_regs.h"
19#include "i810_main.h"
20#include "../edid.h"
21
22/* bit locations in the registers */
23#define SCL_DIR_MASK		0x0001
24#define SCL_DIR			0x0002
25#define SCL_VAL_MASK		0x0004
26#define SCL_VAL_OUT		0x0008
27#define SCL_VAL_IN		0x0010
28#define SDA_DIR_MASK		0x0100
29#define SDA_DIR			0x0200
30#define SDA_VAL_MASK		0x0400
31#define SDA_VAL_OUT		0x0800
32#define SDA_VAL_IN		0x1000
33
34#define DEBUG  /* define this for verbose EDID parsing output */
35
36#ifdef DEBUG
37#define DPRINTK(fmt, args...) printk(fmt,## args)
38#else
39#define DPRINTK(fmt, args...)
40#endif
41
42static void i810i2c_setscl(void *data, int state)
43{
44        struct i810fb_i2c_chan    *chan = data;
45        struct i810fb_par         *par = chan->par;
46	u8                        __iomem *mmio = par->mmio_start_virtual;
47
48	if (state)
49		i810_writel(mmio, chan->ddc_base, SCL_DIR_MASK | SCL_VAL_MASK);
50	else
51		i810_writel(mmio, chan->ddc_base, SCL_DIR | SCL_DIR_MASK | SCL_VAL_MASK);
52	i810_readl(mmio, chan->ddc_base);	/* flush posted write */
53}
54
55static void i810i2c_setsda(void *data, int state)
56{
57        struct i810fb_i2c_chan    *chan = data;
58        struct i810fb_par         *par = chan->par;
59	u8                        __iomem *mmio = par->mmio_start_virtual;
60
61	if (state)
62		i810_writel(mmio, chan->ddc_base, SDA_DIR_MASK | SDA_VAL_MASK);
63	else
64		i810_writel(mmio, chan->ddc_base, SDA_DIR | SDA_DIR_MASK | SDA_VAL_MASK);
65	i810_readl(mmio, chan->ddc_base);	/* flush posted write */
66}
67
68static int i810i2c_getscl(void *data)
69{
70        struct i810fb_i2c_chan    *chan = data;
71        struct i810fb_par         *par = chan->par;
72	u8                        __iomem *mmio = par->mmio_start_virtual;
73
74	i810_writel(mmio, chan->ddc_base, SCL_DIR_MASK);
75	i810_writel(mmio, chan->ddc_base, 0);
76	return ((i810_readl(mmio, chan->ddc_base) & SCL_VAL_IN) != 0);
77}
78
79static int i810i2c_getsda(void *data)
80{
81        struct i810fb_i2c_chan    *chan = data;
82        struct i810fb_par         *par = chan->par;
83	u8                        __iomem *mmio = par->mmio_start_virtual;
84
85	i810_writel(mmio, chan->ddc_base, SDA_DIR_MASK);
86	i810_writel(mmio, chan->ddc_base, 0);
87	return ((i810_readl(mmio, chan->ddc_base) & SDA_VAL_IN) != 0);
88}
89
90static int i810_setup_i2c_bus(struct i810fb_i2c_chan *chan, const char *name)
91{
92        int rc;
93
94        strcpy(chan->adapter.name, name);
95        chan->adapter.owner             = THIS_MODULE;
96        chan->adapter.algo_data         = &chan->algo;
97        chan->adapter.dev.parent        = &chan->par->dev->dev;
98	chan->algo.setsda               = i810i2c_setsda;
99	chan->algo.setscl               = i810i2c_setscl;
100	chan->algo.getsda               = i810i2c_getsda;
101	chan->algo.getscl               = i810i2c_getscl;
102	chan->algo.udelay               = 10;
103        chan->algo.timeout              = (HZ/2);
104        chan->algo.data                 = chan;
105
106        i2c_set_adapdata(&chan->adapter, chan);
107
108        /* Raise SCL and SDA */
109        chan->algo.setsda(chan, 1);
110        chan->algo.setscl(chan, 1);
111        udelay(20);
112
113        rc = i2c_bit_add_bus(&chan->adapter);
114
115        if (rc == 0)
116                dev_dbg(&chan->par->dev->dev, "I2C bus %s registered.\n",name);
117        else {
118                dev_warn(&chan->par->dev->dev, "Failed to register I2C bus "
119			 "%s.\n", name);
120		chan->par = NULL;
121	}
122
123        return rc;
124}
125
126void i810_create_i2c_busses(struct i810fb_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 = GPIOA;
133	i810_setup_i2c_bus(&par->chan[0], "I810-DDC");
134	par->chan[1].ddc_base = GPIOB;
135	i810_setup_i2c_bus(&par->chan[1], "I810-I2C");
136	par->chan[2].ddc_base = GPIOC;
137	i810_setup_i2c_bus(&par->chan[2], "I810-GPIOC");
138}
139
140void i810_delete_i2c_busses(struct i810fb_par *par)
141{
142        if (par->chan[0].par)
143		i2c_del_adapter(&par->chan[0].adapter);
144        par->chan[0].par = NULL;
145
146	if (par->chan[1].par)
147		i2c_del_adapter(&par->chan[1].adapter);
148	par->chan[1].par = NULL;
149
150	if (par->chan[2].par)
151		i2c_del_adapter(&par->chan[2].adapter);
152	par->chan[2].par = NULL;
153}
154
155int i810_probe_i2c_connector(struct fb_info *info, u8 **out_edid, int conn)
156{
157	struct i810fb_par *par = info->par;
158        u8 *edid = NULL;
159
160	DPRINTK("i810-i2c: Probe DDC%i Bus\n", conn+1);
161	if (conn < par->ddc_num) {
162		edid = fb_ddc_read(&par->chan[conn].adapter);
163	} else {
164		const u8 *e = fb_firmware_edid(info->device);
165
166		if (e != NULL) {
167			DPRINTK("i810-i2c: Getting EDID from BIOS\n");
168			edid = kmemdup(e, EDID_LENGTH, GFP_KERNEL);
169		}
170	}
171
172	*out_edid = edid;
173
174        return (edid) ? 0 : 1;
175}
176