drivers/video/riva/rivafb-i2c.c

   1 /*
   2  * linux/drivers/video/riva/fbdev-i2c.c - nVidia i2c
   3  *
   4  * Maintained by Ani Joshi <ajoshi@shell.unixbox.com>
   5  *
   6  * Copyright 2004 Antonino A. Daplas <adaplas @pol.net>
   7  *
   8  * Based on radeonfb-i2c.c
   9  *
  10  * This file is subject to the terms and conditions of the GNU General Public
  11  * License.  See the file COPYING in the main directory of this archive
  12  * for more details.
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/kernel.h>
  17 #include <linux/delay.h>
  18 #include <linux/pci.h>
  19 #include <linux/fb.h>
  20 #include <linux/jiffies.h>
  21
  22 #include <asm/io.h>
  23
  24 #include "rivafb.h"
  25 #include "../edid.h"
  26
  27 static void riva_gpio_setscl(void* data, int state)
  28 {
  29         struct riva_i2c_chan    *chan = data;
  30         struct riva_par         *par = chan->par;
  31         u32                     val;
  32
  33         VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base + 1);
  34         val = VGA_RD08(par->riva.PCIO, 0x3d5) & 0xf0;
  35
  36         if (state)
  37                 val |= 0x20;
  38         else
  39                 val &= ~0x20;
  40
  41         VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base + 1);
  42         VGA_WR08(par->riva.PCIO, 0x3d5, val | 0x1);
  43 }
  44
  45 static void riva_gpio_setsda(void* data, int state)
  46 {
  47         struct riva_i2c_chan    *chan = data;
  48         struct riva_par         *par = chan->par;
  49         u32                     val;
  50
  51         VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base + 1);
  52         val = VGA_RD08(par->riva.PCIO, 0x3d5) & 0xf0;
  53
  54         if (state)
  55                 val |= 0x10;
  56         else
  57                 val &= ~0x10;
  58
  59         VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base + 1);
  60         VGA_WR08(par->riva.PCIO, 0x3d5, val | 0x1);
  61 }
  62
  63 static int riva_gpio_getscl(void* data)
  64 {
  65         struct riva_i2c_chan    *chan = data;
  66         struct riva_par         *par = chan->par;
  67         u32                     val = 0;
  68
  69         VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base);
  70         if (VGA_RD08(par->riva.PCIO, 0x3d5) & 0x04)
  71                 val = 1;
  72
  73         return val;
  74 }
  75
  76 static int riva_gpio_getsda(void* data)
  77 {
  78         struct riva_i2c_chan    *chan = data;
  79         struct riva_par         *par = chan->par;
  80         u32                     val = 0;
  81
  82         VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base);
  83         if (VGA_RD08(par->riva.PCIO, 0x3d5) & 0x08)
  84                 val = 1;
  85
  86         return val;
  87 }
  88
  89 static int __devinit riva_setup_i2c_bus(struct riva_i2c_chan *chan,
  90                                         const char *name,
  91                                         unsigned int i2c_class)
  92 {
  93         int rc;
  94
  95         strcpy(chan->adapter.name, name);
  96         chan->adapter.owner             = THIS_MODULE;
  97         chan->adapter.class             = i2c_class;
  98         chan->adapter.algo_data         = &chan->algo;
  99         chan->adapter.dev.parent        = &chan->par->pdev->dev;
 100         chan->algo.setsda               = riva_gpio_setsda;
 101         chan->algo.setscl               = riva_gpio_setscl;
 102         chan->algo.getsda               = riva_gpio_getsda;
 103         chan->algo.getscl               = riva_gpio_getscl;
 104         chan->algo.udelay               = 40;
 105         chan->algo.timeout              = msecs_to_jiffies(2);
 106         chan->algo.data                 = chan;
 107
 108         i2c_set_adapdata(&chan->adapter, chan);
 109
 110         /* Raise SCL and SDA */
 111         riva_gpio_setsda(chan, 1);
 112         riva_gpio_setscl(chan, 1);
 113         udelay(20);
 114
 115         rc = i2c_bit_add_bus(&chan->adapter);
 116         if (rc == 0)
 117                 dev_dbg(&chan->par->pdev->dev, "I2C bus %s registered.\n", name);
 118         else {
 119                 dev_warn(&chan->par->pdev->dev,
 120                          "Failed to register I2C bus %s.\n", name);
 121                 chan->par = NULL;
 122         }
 123
 124         return rc;
 125 }
 126
 127 void __devinit riva_create_i2c_busses(struct riva_par *par)
 128 {
 129         par->chan[0].par        = par;
 130         par->chan[1].par        = par;
 131         par->chan[2].par        = par;
 132
 133         par->chan[0].ddc_base = 0x36;
 134         par->chan[1].ddc_base = 0x3e;
 135         par->chan[2].ddc_base = 0x50;
 136         riva_setup_i2c_bus(&par->chan[0], "BUS1", I2C_CLASS_HWMON);
 137         riva_setup_i2c_bus(&par->chan[1], "BUS2", 0);
 138         riva_setup_i2c_bus(&par->chan[2], "BUS3", 0);
 139 }
 140
 141 void riva_delete_i2c_busses(struct riva_par *par)
 142 {
 143         int i;
 144
 145         for (i = 0; i < 3; i++) {
 146                 if (!par->chan[i].par)
 147                         continue;
 148                 i2c_del_adapter(&par->chan[i].adapter);
 149                 par->chan[i].par = NULL;
 150         }
 151 }
 152
 153 int __devinit riva_probe_i2c_connector(struct riva_par *par, int conn, u8 **out_edid)
 154 {
 155         u8 *edid = NULL;
 156
 157         if (par->chan[conn].par)
 158                 edid = fb_ddc_read(&par->chan[conn].adapter);
 159
 160         if (out_edid)
 161                 *out_edid = edid;
 162         if (!edid)
 163                 return 1;
 164
 165         return 0;
 166 }
 167