drivers/video/i810/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/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
  41 static 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
  52 static 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
  63 static 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
  74 static 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
  85 static 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
 122 void 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
 136 void 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
 151 int 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 }