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 "../edid.h"
  21
  22 #define I810_DDC 0x50
  23 /* bit locations in the registers */
  24 #define SCL_DIR_MASK            0x0001
  25 #define SCL_DIR                 0x0002
  26 #define SCL_VAL_MASK            0x0004
  27 #define SCL_VAL_OUT             0x0008
  28 #define SCL_VAL_IN              0x0010
  29 #define SDA_DIR_MASK            0x0100
  30 #define SDA_DIR                 0x0200
  31 #define SDA_VAL_MASK            0x0400
  32 #define SDA_VAL_OUT             0x0800
  33 #define SDA_VAL_IN              0x1000
  34
  35 #define DEBUG  /* define this for verbose EDID parsing output */
  36
  37 #ifdef DEBUG
  38 #define DPRINTK(fmt, args...) printk(fmt,## args)
  39 #else
  40 #define DPRINTK(fmt, args...)
  41 #endif
  42
  43 static void i810i2c_setscl(void *data, int state)
  44 {
  45         struct i810fb_i2c_chan    *chan = (struct i810fb_i2c_chan *)data;
  46         struct i810fb_par         *par = chan->par;
  47         u8                        *mmio = par->mmio_start_virtual;
  48
  49         i810_writel(mmio, GPIOB, (state ? SCL_VAL_OUT : 0) | SCL_DIR |
  50                     SCL_DIR_MASK | SCL_VAL_MASK);
  51         i810_readl(mmio, GPIOB);        /* flush posted write */
  52 }
  53
  54 static void i810i2c_setsda(void *data, int state)
  55 {
  56         struct i810fb_i2c_chan    *chan = (struct i810fb_i2c_chan *)data;
  57         struct i810fb_par         *par = chan->par;
  58         u8                        *mmio = par->mmio_start_virtual;
  59
  60         i810_writel(mmio, GPIOB, (state ? SDA_VAL_OUT : 0) | SDA_DIR |
  61                     SDA_DIR_MASK | SDA_VAL_MASK);
  62         i810_readl(mmio, GPIOB);        /* flush posted write */
  63 }
  64
  65 static int i810i2c_getscl(void *data)
  66 {
  67         struct i810fb_i2c_chan    *chan = (struct i810fb_i2c_chan *)data;
  68         struct i810fb_par         *par = chan->par;
  69         u8                        *mmio = par->mmio_start_virtual;
  70
  71         i810_writel(mmio, GPIOB, SCL_DIR_MASK);
  72         i810_writel(mmio, GPIOB, 0);
  73         return (0 != (i810_readl(mmio, GPIOB) & SCL_VAL_IN));
  74 }
  75
  76 static int i810i2c_getsda(void *data)
  77 {
  78         struct i810fb_i2c_chan    *chan = (struct i810fb_i2c_chan *)data;
  79         struct i810fb_par         *par = chan->par;
  80         u8                        *mmio = par->mmio_start_virtual;
  81
  82         i810_writel(mmio, GPIOB, SDA_DIR_MASK);
  83         i810_writel(mmio, GPIOB, 0);
  84         return (0 != (i810_readl(mmio, GPIOB) & SDA_VAL_IN));
  85 }
  86
  87 static void i810ddc_setscl(void *data, int state)
  88 {
  89         struct i810fb_i2c_chan    *chan = (struct i810fb_i2c_chan *)data;
  90         struct i810fb_par       *par = chan->par;
  91         u8                      *mmio = par->mmio_start_virtual;
  92
  93         i810_writel(mmio, GPIOA, (state ? SCL_VAL_OUT : 0) | SCL_DIR |
  94                     SCL_DIR_MASK | SCL_VAL_MASK);
  95         i810_readl(mmio, GPIOA);        /* flush posted write */
  96 }
  97
  98 static void i810ddc_setsda(void *data, int state)
  99 {
 100         struct i810fb_i2c_chan    *chan = (struct i810fb_i2c_chan *)data;
 101         struct i810fb_par         *par = chan->par;
 102         u8                      *mmio = par->mmio_start_virtual;
 103
 104         i810_writel(mmio, GPIOA, (state ? SDA_VAL_OUT : 0) | SDA_DIR |
 105                     SDA_DIR_MASK | SDA_VAL_MASK);
 106         i810_readl(mmio, GPIOA);        /* flush posted write */
 107 }
 108
 109 static int i810ddc_getscl(void *data)
 110 {
 111         struct i810fb_i2c_chan    *chan = (struct i810fb_i2c_chan *)data;
 112         struct i810fb_par         *par = chan->par;
 113         u8                      *mmio = par->mmio_start_virtual;
 114
 115         i810_writel(mmio, GPIOA, SCL_DIR_MASK);
 116         i810_writel(mmio, GPIOA, 0);
 117         return (0 != (i810_readl(mmio, GPIOA) & SCL_VAL_IN));
 118 }
 119
 120 static int i810ddc_getsda(void *data)
 121 {
 122         struct i810fb_i2c_chan    *chan = (struct i810fb_i2c_chan *)data;
 123         struct i810fb_par         *par = chan->par;
 124         u8                      *mmio = par->mmio_start_virtual;
 125
 126         i810_writel(mmio, GPIOA, SDA_DIR_MASK);
 127         i810_writel(mmio, GPIOA, 0);
 128         return (0 != (i810_readl(mmio, GPIOA) & SDA_VAL_IN));
 129 }
 130
 131 #define I2C_ALGO_DDC_I810   0x0e0000
 132 #define I2C_ALGO_I2C_I810   0x0f0000
 133 static int i810_setup_i2c_bus(struct i810fb_i2c_chan *chan, const char *name,
 134                               int conn)
 135 {
 136         int rc;
 137
 138         strcpy(chan->adapter.name, name);
 139         chan->adapter.owner             = THIS_MODULE;
 140         chan->adapter.algo_data         = &chan->algo;
 141         chan->adapter.dev.parent        = &chan->par->dev->dev;
 142         switch (conn) {
 143         case 1:
 144                 chan->adapter.id                = I2C_ALGO_DDC_I810;
 145                 chan->algo.setsda               = i810ddc_setsda;
 146                 chan->algo.setscl               = i810ddc_setscl;
 147                 chan->algo.getsda               = i810ddc_getsda;
 148                 chan->algo.getscl               = i810ddc_getscl;
 149                 break;
 150         case 2:
 151                 chan->adapter.id                = I2C_ALGO_I2C_I810;
 152                 chan->algo.setsda               = i810i2c_setsda;
 153                 chan->algo.setscl               = i810i2c_setscl;
 154                 chan->algo.getsda               = i810i2c_getsda;
 155                 chan->algo.getscl               = i810i2c_getscl;
 156                 break;
 157         }
 158         chan->algo.udelay               = 10;
 159         chan->algo.mdelay               = 10;
 160         chan->algo.timeout              = (HZ/2);
 161         chan->algo.data                 = chan;
 162
 163         i2c_set_adapdata(&chan->adapter, chan);
 164
 165         /* Raise SCL and SDA */
 166         chan->algo.setsda(chan, 1);
 167         chan->algo.setscl(chan, 1);
 168         udelay(20);
 169
 170         rc = i2c_bit_add_bus(&chan->adapter);
 171         if (rc == 0)
 172                 dev_dbg(&chan->par->dev->dev, "I2C bus %s registered.\n",name);
 173         else
 174                 dev_warn(&chan->par->dev->dev, "Failed to register I2C bus "
 175                          "%s.\n", name);
 176         return rc;
 177 }
 178
 179 void i810_create_i2c_busses(struct i810fb_par *par)
 180 {
 181         par->chan[0].par        = par;
 182         par->chan[1].par        = par;
 183         i810_setup_i2c_bus(&par->chan[0], "I810-DDC", 1);
 184         i810_setup_i2c_bus(&par->chan[1], "I810-I2C", 2);
 185 }
 186
 187 void i810_delete_i2c_busses(struct i810fb_par *par)
 188 {
 189         if (par->chan[0].par)
 190                 i2c_bit_del_bus(&par->chan[0].adapter);
 191         par->chan[0].par = NULL;
 192         if (par->chan[1].par)
 193                 i2c_bit_del_bus(&par->chan[1].adapter);
 194         par->chan[1].par = NULL;
 195 }
 196
 197 static u8 *i810_do_probe_i2c_edid(struct i810fb_i2c_chan *chan)
 198 {
 199         u8 start = 0x0;
 200         struct i2c_msg msgs[] = {
 201                 {
 202                         .addr   = I810_DDC,
 203                         .len    = 1,
 204                         .buf    = &start,
 205                 }, {
 206                         .addr   = I810_DDC,
 207                         .flags  = I2C_M_RD,
 208                         .len    = EDID_LENGTH,
 209                 },
 210         };
 211         u8 *buf;
 212
 213         buf = kmalloc(EDID_LENGTH, GFP_KERNEL);
 214         if (!buf) {
 215                 DPRINTK("i810-i2c: Failed to allocate memory\n");
 216                 return NULL;
 217         }
 218         msgs[1].buf = buf;
 219
 220         if (i2c_transfer(&chan->adapter, msgs, 2) == 2) {
 221                 DPRINTK("i810-i2c: I2C Transfer successful\n");
 222                 return buf;
 223         }
 224         DPRINTK("i810-i2c: Unable to read EDID block.\n");
 225         kfree(buf);
 226         return NULL;
 227 }
 228
 229 int i810_probe_i2c_connector(struct fb_info *info, u8 **out_edid, int conn)
 230 {
 231         struct i810fb_par *par = info->par;
 232         u8 *edid = NULL;
 233         int i;
 234
 235         DPRINTK("i810-i2c: Probe DDC%i Bus\n", conn);
 236         if (conn < 3) {
 237                 for (i = 0; i < 3; i++) {
 238                         /* Do the real work */
 239                         edid = i810_do_probe_i2c_edid(&par->chan[conn-1]);
 240                         if (edid)
 241                                 break;
 242                 }
 243         } else {
 244                 DPRINTK("i810-i2c: Getting EDID from BIOS\n");
 245                 edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
 246                 if (edid)
 247                         memcpy(edid, fb_firmware_edid(info->device),
 248                                EDID_LENGTH);
 249         }
 250
 251         if (out_edid)
 252                 *out_edid = edid;
 253
 254         return (edid) ? 0 : 1;
 255 }
 256
 257