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/pci.h>
15#include <linux/fb.h>
16#include "i810.h"
17#include "i810_regs.h"
18#include "i810_main.h"
19#include "../edid.h"
20
21/* bit locations in the registers */
22#define SCL_DIR_MASK		0x0001
23#define SCL_DIR			0x0002
24#define SCL_VAL_MASK		0x0004
25#define SCL_VAL_OUT		0x0008
26#define SCL_VAL_IN		0x0010
27#define SDA_DIR_MASK		0x0100
28#define SDA_DIR			0x0200
29#define SDA_VAL_MASK		0x0400
30#define SDA_VAL_OUT		0x0800
31#define SDA_VAL_IN		0x1000
32
33#define DEBUG  /* define this for verbose EDID parsing output */
34
35#ifdef DEBUG
36#define DPRINTK(fmt, args...) printk(fmt,## args)
37#else
38#define DPRINTK(fmt, args...)
39#endif
40
41static void i810i2c_setscl(void *data, int state)
42{
43        struct i810fb_i2c_chan    *chan = data;
44        struct i810fb_par         *par = chan->par;
45	u8                        __iomem *mmio = par->mmio_start_virtual;
46
47	i810_writel(mmio, chan->ddc_base, (state ? SCL_VAL_OUT : 0) | SCL_DIR |
48		    SCL_DIR_MASK | SCL_VAL_MASK);
49	i810_readl(mmio, chan->ddc_base);	/* flush posted write */
50}
51
52static void i810i2c_setsda(void *data, int state)
53{
54        struct i810fb_i2c_chan    *chan = data;
55        struct i810fb_par         *par = chan->par;
56	u8                        __iomem *mmio = par->mmio_start_virtual;
57
58 	i810_writel(mmio, chan->ddc_base, (state ? SDA_VAL_OUT : 0) | SDA_DIR |
59		    SDA_DIR_MASK | SDA_VAL_MASK);
60	i810_readl(mmio, chan->ddc_base);	/* flush posted write */
61}
62
63static int i810i2c_getscl(void *data)
64{
65        struct i810fb_i2c_chan    *chan = data;
66        struct i810fb_par         *par = chan->par;
67	u8                        __iomem *mmio = par->mmio_start_virtual;
68
69	i810_writel(mmio, chan->ddc_base, SCL_DIR_MASK);
70	i810_writel(mmio, chan->ddc_base, 0);
71	return ((i810_readl(mmio, chan->ddc_base) & SCL_VAL_IN) != 0);
72}
73
74static int i810i2c_getsda(void *data)
75{
76        struct i810fb_i2c_chan    *chan = data;
77        struct i810fb_par         *par = chan->par;
78	u8                        __iomem *mmio = par->mmio_start_virtual;
79
80	i810_writel(mmio, chan->ddc_base, SDA_DIR_MASK);
81	i810_writel(mmio, chan->ddc_base, 0);
82	return ((i810_readl(mmio, chan->ddc_base) & SDA_VAL_IN) != 0);
83}
84
85static int i810_setup_i2c_bus(struct i810fb_i2c_chan *chan, const char *name)
86{
87        int rc;
88
89        strcpy(chan->adapter.name, name);
90        chan->adapter.owner             = THIS_MODULE;
91        chan->adapter.algo_data         = &chan->algo;
92        chan->adapter.dev.parent        = &chan->par->dev->dev;
93	chan->adapter.id                = I2C_HW_B_I810;
94	chan->algo.setsda               = i810i2c_setsda;
95	chan->algo.setscl               = i810i2c_setscl;
96	chan->algo.getsda               = i810i2c_getsda;
97	chan->algo.getscl               = i810i2c_getscl;
98	chan->algo.udelay               = 10;
99        chan->algo.timeout              = (HZ/2);
100        chan->algo.data                 = chan;
101
102        i2c_set_adapdata(&chan->adapter, chan);
103
104        /* Raise SCL and SDA */
105        chan->algo.setsda(chan, 1);
106        chan->algo.setscl(chan, 1);
107        udelay(20);
108
109        rc = i2c_bit_add_bus(&chan->adapter);
110
111        if (rc == 0)
112                dev_dbg(&chan->par->dev->dev, "I2C bus %s registered.\n",name);
113        else {
114                dev_warn(&chan->par->dev->dev, "Failed to register I2C bus "
115			 "%s.\n", name);
116		chan->par = NULL;
117	}
118
119        return rc;
120}
121
122void i810_create_i2c_busses(struct i810fb_par *par)
123{
124        par->chan[0].par        = par;
125	par->chan[1].par        = par;
126	par->chan[2].par        = par;
127
128	par->chan[0].ddc_base = GPIOA;
129	i810_setup_i2c_bus(&par->chan[0], "I810-DDC");
130	par->chan[1].ddc_base = GPIOB;
131	i810_setup_i2c_bus(&par->chan[1], "I810-I2C");
132	par->chan[2].ddc_base = GPIOC;
133	i810_setup_i2c_bus(&par->chan[2], "I810-GPIOC");
134}
135
136void i810_delete_i2c_busses(struct i810fb_par *par)
137{
138        if (par->chan[0].par)
139		i2c_del_adapter(&par->chan[0].adapter);
140        par->chan[0].par = NULL;
141
142	if (par->chan[1].par)
143		i2c_del_adapter(&par->chan[1].adapter);
144	par->chan[1].par = NULL;
145
146	if (par->chan[2].par)
147		i2c_del_adapter(&par->chan[2].adapter);
148	par->chan[2].par = NULL;
149}
150
151int i810_probe_i2c_connector(struct fb_info *info, u8 **out_edid, int conn)
152{
153	struct i810fb_par *par = info->par;
154        u8 *edid = NULL;
155
156	DPRINTK("i810-i2c: Probe DDC%i Bus\n", conn+1);
157	if (conn < par->ddc_num) {
158		edid = fb_ddc_read(&par->chan[conn].adapter);
159	} else {
160		const u8 *e = fb_firmware_edid(info->device);
161
162		if (e != NULL) {
163			DPRINTK("i810-i2c: Getting EDID from BIOS\n");
164			edid = kmemdup(e, EDID_LENGTH, GFP_KERNEL);
165		}
166	}
167
168	*out_edid = edid;
169
170        return (edid) ? 0 : 1;
171}
172