drivers/video/fbdev/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/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
  42 static 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
  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         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
  68 static 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
  79 static 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
  90 static 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
 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_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
 155 int 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 }