linux/drivers/video/fbdev/i810/i810-i2c.c
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   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