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/sched.h>
  14 #include <linux/delay.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         i810_writel(mmio, chan->ddc_base, (state ? SCL_VAL_OUT : 0) | SCL_DIR |
  49                     SCL_DIR_MASK | SCL_VAL_MASK);
  50         i810_readl(mmio, chan->ddc_base);       /* flush posted write */
  51 }
  52
  53 static void i810i2c_setsda(void *data, int state)
  54 {
  55         struct i810fb_i2c_chan    *chan = data;
  56         struct i810fb_par         *par = chan->par;
  57         u8                        __iomem *mmio = par->mmio_start_virtual;
  58
  59         i810_writel(mmio, chan->ddc_base, (state ? SDA_VAL_OUT : 0) | SDA_DIR |
  60                     SDA_DIR_MASK | SDA_VAL_MASK);
  61         i810_readl(mmio, chan->ddc_base);       /* flush posted write */
  62 }
  63
  64 static int i810i2c_getscl(void *data)
  65 {
  66         struct i810fb_i2c_chan    *chan = data;
  67         struct i810fb_par         *par = chan->par;
  68         u8                        __iomem *mmio = par->mmio_start_virtual;
  69
  70         i810_writel(mmio, chan->ddc_base, SCL_DIR_MASK);
  71         i810_writel(mmio, chan->ddc_base, 0);
  72         return ((i810_readl(mmio, chan->ddc_base) & SCL_VAL_IN) != 0);
  73 }
  74
  75 static int i810i2c_getsda(void *data)
  76 {
  77         struct i810fb_i2c_chan    *chan = data;
  78         struct i810fb_par         *par = chan->par;
  79         u8                        __iomem *mmio = par->mmio_start_virtual;
  80
  81         i810_writel(mmio, chan->ddc_base, SDA_DIR_MASK);
  82         i810_writel(mmio, chan->ddc_base, 0);
  83         return ((i810_readl(mmio, chan->ddc_base) & SDA_VAL_IN) != 0);
  84 }
  85
  86 static int i810_setup_i2c_bus(struct i810fb_i2c_chan *chan, const char *name)
  87 {
  88         int rc;
  89
  90         strcpy(chan->adapter.name, name);
  91         chan->adapter.owner             = THIS_MODULE;
  92         chan->adapter.algo_data         = &chan->algo;
  93         chan->adapter.dev.parent        = &chan->par->dev->dev;
  94         chan->adapter.id                = I2C_HW_B_I810;
  95         chan->algo.setsda               = i810i2c_setsda;
  96         chan->algo.setscl               = i810i2c_setscl;
  97         chan->algo.getsda               = i810i2c_getsda;
  98         chan->algo.getscl               = i810i2c_getscl;
  99         chan->algo.udelay               = 10;
 100         chan->algo.timeout              = (HZ/2);
 101         chan->algo.data                 = chan;
 102
 103         i2c_set_adapdata(&chan->adapter, chan);
 104
 105         /* Raise SCL and SDA */
 106         chan->algo.setsda(chan, 1);
 107         chan->algo.setscl(chan, 1);
 108         udelay(20);
 109
 110         rc = i2c_bit_add_bus(&chan->adapter);
 111
 112         if (rc == 0)
 113                 dev_dbg(&chan->par->dev->dev, "I2C bus %s registered.\n",name);
 114         else {
 115                 dev_warn(&chan->par->dev->dev, "Failed to register I2C bus "
 116                          "%s.\n", name);
 117                 chan->par = NULL;
 118         }
 119
 120         return rc;
 121 }
 122
 123 void i810_create_i2c_busses(struct i810fb_par *par)
 124 {
 125         par->chan[0].par        = par;
 126         par->chan[1].par        = par;
 127         par->chan[2].par        = par;
 128
 129         par->chan[0].ddc_base = GPIOA;
 130         i810_setup_i2c_bus(&par->chan[0], "I810-DDC");
 131         par->chan[1].ddc_base = GPIOB;
 132         i810_setup_i2c_bus(&par->chan[1], "I810-I2C");
 133         par->chan[2].ddc_base = GPIOC;
 134         i810_setup_i2c_bus(&par->chan[2], "I810-GPIOC");
 135 }
 136
 137 void i810_delete_i2c_busses(struct i810fb_par *par)
 138 {
 139         if (par->chan[0].par)
 140                 i2c_bit_del_bus(&par->chan[0].adapter);
 141         par->chan[0].par = NULL;
 142
 143         if (par->chan[1].par)
 144                 i2c_bit_del_bus(&par->chan[1].adapter);
 145         par->chan[1].par = NULL;
 146
 147         if (par->chan[2].par)
 148                 i2c_bit_del_bus(&par->chan[2].adapter);
 149         par->chan[2].par = NULL;
 150 }
 151
 152 int i810_probe_i2c_connector(struct fb_info *info, u8 **out_edid, int conn)
 153 {
 154         struct i810fb_par *par = info->par;
 155         u8 *edid = NULL;
 156
 157         DPRINTK("i810-i2c: Probe DDC%i Bus\n", conn+1);
 158         if (conn < par->ddc_num) {
 159                 edid = fb_ddc_read(&par->chan[conn].adapter);
 160         } else {
 161                 const u8 *e = fb_firmware_edid(info->device);
 162
 163                 if (e != NULL) {
 164                         DPRINTK("i810-i2c: Getting EDID from BIOS\n");
 165                         edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
 166                         if (edid)
 167                                 memcpy(edid, e, EDID_LENGTH);
 168                 }
 169         }
 170
 171         *out_edid = edid;
 172
 173         return (edid) ? 0 : 1;
 174 }