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 = data;
  46         struct i810fb_par         *par = chan->par;
  47         u8                        __iomem *mmio = par->mmio_start_virtual;
  48
  49         i810_writel(mmio, chan->ddc_base, (state ? SCL_VAL_OUT : 0) | SCL_DIR |
  50                     SCL_DIR_MASK | SCL_VAL_MASK);
  51         i810_readl(mmio, chan->ddc_base);       /* flush posted write */
  52 }
  53
  54 static void i810i2c_setsda(void *data, int state)
  55 {
  56         struct i810fb_i2c_chan    *chan = data;
  57         struct i810fb_par         *par = chan->par;
  58         u8                        __iomem *mmio = par->mmio_start_virtual;
  59
  60         i810_writel(mmio, chan->ddc_base, (state ? SDA_VAL_OUT : 0) | SDA_DIR |
  61                     SDA_DIR_MASK | SDA_VAL_MASK);
  62         i810_readl(mmio, chan->ddc_base);       /* flush posted write */
  63 }
  64
  65 static int i810i2c_getscl(void *data)
  66 {
  67         struct i810fb_i2c_chan    *chan = data;
  68         struct i810fb_par         *par = chan->par;
  69         u8                        __iomem *mmio = par->mmio_start_virtual;
  70
  71         i810_writel(mmio, chan->ddc_base, SCL_DIR_MASK);
  72         i810_writel(mmio, chan->ddc_base, 0);
  73         return ((i810_readl(mmio, chan->ddc_base) & SCL_VAL_IN) != 0);
  74 }
  75
  76 static int i810i2c_getsda(void *data)
  77 {
  78         struct i810fb_i2c_chan    *chan = data;
  79         struct i810fb_par         *par = chan->par;
  80         u8                        __iomem *mmio = par->mmio_start_virtual;
  81
  82         i810_writel(mmio, chan->ddc_base, SDA_DIR_MASK);
  83         i810_writel(mmio, chan->ddc_base, 0);
  84         return ((i810_readl(mmio, chan->ddc_base) & SDA_VAL_IN) != 0);
  85 }
  86
  87 static int i810_setup_i2c_bus(struct i810fb_i2c_chan *chan, const char *name)
  88 {
  89         int rc;
  90
  91         strcpy(chan->adapter.name, name);
  92         chan->adapter.owner             = THIS_MODULE;
  93         chan->adapter.algo_data         = &chan->algo;
  94         chan->adapter.dev.parent        = &chan->par->dev->dev;
  95         chan->adapter.id                = I2C_HW_B_I810;
  96         chan->algo.setsda               = i810i2c_setsda;
  97         chan->algo.setscl               = i810i2c_setscl;
  98         chan->algo.getsda               = i810i2c_getsda;
  99         chan->algo.getscl               = i810i2c_getscl;
 100         chan->algo.udelay               = 10;
 101         chan->algo.mdelay               = 10;
 102         chan->algo.timeout              = (HZ/2);
 103         chan->algo.data                 = chan;
 104
 105         i2c_set_adapdata(&chan->adapter, chan);
 106
 107         /* Raise SCL and SDA */
 108         chan->algo.setsda(chan, 1);
 109         chan->algo.setscl(chan, 1);
 110         udelay(20);
 111
 112         rc = i2c_bit_add_bus(&chan->adapter);
 113
 114         if (rc == 0)
 115                 dev_dbg(&chan->par->dev->dev, "I2C bus %s registered.\n",name);
 116         else {
 117                 dev_warn(&chan->par->dev->dev, "Failed to register I2C bus "
 118                          "%s.\n", name);
 119                 chan->par = NULL;
 120         }
 121
 122         return rc;
 123 }
 124
 125 void i810_create_i2c_busses(struct i810fb_par *par)
 126 {
 127         par->chan[0].par        = par;
 128         par->chan[1].par        = par;
 129         par->chan[2].par        = par;
 130
 131         par->chan[0].ddc_base = GPIOA;
 132         i810_setup_i2c_bus(&par->chan[0], "I810-DDC");
 133         par->chan[1].ddc_base = GPIOB;
 134         i810_setup_i2c_bus(&par->chan[1], "I810-I2C");
 135         par->chan[2].ddc_base = GPIOC;
 136         i810_setup_i2c_bus(&par->chan[2], "I810-GPIOC");
 137 }
 138
 139 void i810_delete_i2c_busses(struct i810fb_par *par)
 140 {
 141         if (par->chan[0].par)
 142                 i2c_bit_del_bus(&par->chan[0].adapter);
 143         par->chan[0].par = NULL;
 144
 145         if (par->chan[1].par)
 146                 i2c_bit_del_bus(&par->chan[1].adapter);
 147         par->chan[1].par = NULL;
 148
 149         if (par->chan[2].par)
 150                 i2c_bit_del_bus(&par->chan[2].adapter);
 151         par->chan[2].par = NULL;
 152 }
 153
 154 static u8 *i810_do_probe_i2c_edid(struct i810fb_i2c_chan *chan)
 155 {
 156         u8 start = 0x0;
 157         struct i2c_msg msgs[] = {
 158                 {
 159                         .addr   = I810_DDC,
 160                         .len    = 1,
 161                         .buf    = &start,
 162                 }, {
 163                         .addr   = I810_DDC,
 164                         .flags  = I2C_M_RD,
 165                         .len    = EDID_LENGTH,
 166                 },
 167         };
 168         u8 *buf;
 169
 170         buf = kmalloc(EDID_LENGTH, GFP_KERNEL);
 171         if (!buf) {
 172                 DPRINTK("i810-i2c: Failed to allocate memory\n");
 173                 return NULL;
 174         }
 175         msgs[1].buf = buf;
 176
 177         if (i2c_transfer(&chan->adapter, msgs, 2) == 2) {
 178                 DPRINTK("i810-i2c: I2C Transfer successful\n");
 179                 return buf;
 180         }
 181
 182         DPRINTK("i810-i2c: Unable to read EDID block.\n");
 183         kfree(buf);
 184         return NULL;
 185 }
 186
 187 int i810_probe_i2c_connector(struct fb_info *info, u8 **out_edid, int conn)
 188 {
 189         struct i810fb_par *par = info->par;
 190         u8 *edid = NULL;
 191         int i;
 192
 193         DPRINTK("i810-i2c: Probe DDC%i Bus\n", conn);
 194         if (conn < 4) {
 195                 for (i = 0; i < 3; i++) {
 196                         /* Do the real work */
 197                         edid = i810_do_probe_i2c_edid(&par->chan[conn-1]);
 198                         if (edid)
 199                                 break;
 200                 }
 201         } else {
 202                 const u8 *e = fb_firmware_edid(info->device);
 203
 204                 if (e != NULL) {
 205                         DPRINTK("i810-i2c: Getting EDID from BIOS\n");
 206                         edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
 207                         if (edid)
 208                                 memcpy(edid, e, EDID_LENGTH);
 209                 }
 210         }
 211
 212         if (out_edid)
 213                 *out_edid = edid;
 214
 215         return (edid) ? 0 : 1;
 216 }