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/config.h>
  12 #include <linux/module.h>
  13 #include <linux/kernel.h>
  14 #include <linux/sched.h>
  15 #include <linux/delay.h>
  16 #include <linux/pci.h>
  17 #include <linux/fb.h>
  18 #include "i810.h"
  19 #include "i810_regs.h"
  20 #include "i810_main.h"
  21 #include "../edid.h"
  22
  23 #define I810_DDC 0x50
  24 /* bit locations in the registers */
  25 #define SCL_DIR_MASK            0x0001
  26 #define SCL_DIR                 0x0002
  27 #define SCL_VAL_MASK            0x0004
  28 #define SCL_VAL_OUT             0x0008
  29 #define SCL_VAL_IN              0x0010
  30 #define SDA_DIR_MASK            0x0100
  31 #define SDA_DIR                 0x0200
  32 #define SDA_VAL_MASK            0x0400
  33 #define SDA_VAL_OUT             0x0800
  34 #define SDA_VAL_IN              0x1000
  35
  36 #define DEBUG  /* define this for verbose EDID parsing output */
  37
  38 #ifdef DEBUG
  39 #define DPRINTK(fmt, args...) printk(fmt,## args)
  40 #else
  41 #define DPRINTK(fmt, args...)
  42 #endif
  43
  44 static void i810i2c_setscl(void *data, int state)
  45 {
  46         struct i810fb_i2c_chan    *chan = data;
  47         struct i810fb_par         *par = chan->par;
  48         u8                        __iomem *mmio = par->mmio_start_virtual;
  49
  50         i810_writel(mmio, chan->ddc_base, (state ? SCL_VAL_OUT : 0) | SCL_DIR |
  51                     SCL_DIR_MASK | SCL_VAL_MASK);
  52         i810_readl(mmio, chan->ddc_base);       /* flush posted write */
  53 }
  54
  55 static 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         i810_writel(mmio, chan->ddc_base, (state ? SDA_VAL_OUT : 0) | SDA_DIR |
  62                     SDA_DIR_MASK | SDA_VAL_MASK);
  63         i810_readl(mmio, chan->ddc_base);       /* flush posted write */
  64 }
  65
  66 static int i810i2c_getscl(void *data)
  67 {
  68         struct i810fb_i2c_chan    *chan = data;
  69         struct i810fb_par         *par = chan->par;
  70         u8                        __iomem *mmio = par->mmio_start_virtual;
  71
  72         i810_writel(mmio, chan->ddc_base, SCL_DIR_MASK);
  73         i810_writel(mmio, chan->ddc_base, 0);
  74         return ((i810_readl(mmio, chan->ddc_base) & SCL_VAL_IN) != 0);
  75 }
  76
  77 static int i810i2c_getsda(void *data)
  78 {
  79         struct i810fb_i2c_chan    *chan = data;
  80         struct i810fb_par         *par = chan->par;
  81         u8                        __iomem *mmio = par->mmio_start_virtual;
  82
  83         i810_writel(mmio, chan->ddc_base, SDA_DIR_MASK);
  84         i810_writel(mmio, chan->ddc_base, 0);
  85         return ((i810_readl(mmio, chan->ddc_base) & SDA_VAL_IN) != 0);
  86 }
  87
  88 static int i810_setup_i2c_bus(struct i810fb_i2c_chan *chan, const char *name)
  89 {
  90         int rc;
  91
  92         strcpy(chan->adapter.name, name);
  93         chan->adapter.owner             = THIS_MODULE;
  94         chan->adapter.algo_data         = &chan->algo;
  95         chan->adapter.dev.parent        = &chan->par->dev->dev;
  96         chan->adapter.id                = I2C_HW_B_I810;
  97         chan->algo.setsda               = i810i2c_setsda;
  98         chan->algo.setscl               = i810i2c_setscl;
  99         chan->algo.getsda               = i810i2c_getsda;
 100         chan->algo.getscl               = i810i2c_getscl;
 101         chan->algo.udelay               = 10;
 102         chan->algo.mdelay               = 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
 126 void 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
 140 void i810_delete_i2c_busses(struct i810fb_par *par)
 141 {
 142         if (par->chan[0].par)
 143                 i2c_bit_del_bus(&par->chan[0].adapter);
 144         par->chan[0].par = NULL;
 145
 146         if (par->chan[1].par)
 147                 i2c_bit_del_bus(&par->chan[1].adapter);
 148         par->chan[1].par = NULL;
 149
 150         if (par->chan[2].par)
 151                 i2c_bit_del_bus(&par->chan[2].adapter);
 152         par->chan[2].par = NULL;
 153 }
 154
 155 static u8 *i810_do_probe_i2c_edid(struct i810fb_i2c_chan *chan)
 156 {
 157         u8 start = 0x0;
 158         struct i2c_msg msgs[] = {
 159                 {
 160                         .addr   = I810_DDC,
 161                         .len    = 1,
 162                         .buf    = &start,
 163                 }, {
 164                         .addr   = I810_DDC,
 165                         .flags  = I2C_M_RD,
 166                         .len    = EDID_LENGTH,
 167                 },
 168         };
 169         u8 *buf;
 170
 171         buf = kmalloc(EDID_LENGTH, GFP_KERNEL);
 172         if (!buf) {
 173                 DPRINTK("i810-i2c: Failed to allocate memory\n");
 174                 return NULL;
 175         }
 176         msgs[1].buf = buf;
 177
 178         if (i2c_transfer(&chan->adapter, msgs, 2) == 2) {
 179                 DPRINTK("i810-i2c: I2C Transfer successful\n");
 180                 return buf;
 181         }
 182
 183         DPRINTK("i810-i2c: Unable to read EDID block.\n");
 184         kfree(buf);
 185         return NULL;
 186 }
 187
 188 int i810_probe_i2c_connector(struct fb_info *info, u8 **out_edid, int conn)
 189 {
 190         struct i810fb_par *par = info->par;
 191         u8 *edid = NULL;
 192         int i;
 193
 194         DPRINTK("i810-i2c: Probe DDC%i Bus\n", conn+1);
 195         if (conn < par->ddc_num) {
 196                 for (i = 0; i < 3; i++) {
 197                         /* Do the real work */
 198                         edid = i810_do_probe_i2c_edid(&par->chan[conn]);
 199                         if (edid)
 200                                 break;
 201                 }
 202         } else {
 203                 const u8 *e = fb_firmware_edid(info->device);
 204
 205                 if (e != NULL) {
 206                         DPRINTK("i810-i2c: Getting EDID from BIOS\n");
 207                         edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
 208                         if (edid)
 209                                 memcpy(edid, e, EDID_LENGTH);
 210                 }
 211         }
 212
 213         if (out_edid)
 214                 *out_edid = edid;
 215
 216         return (edid) ? 0 : 1;
 217 }