i810-i2c.c

  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}