drivers/video/fbdev/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 riva_setup_i2c_bus(struct riva_i2c_chan *chan, const char *name,
  90                               unsigned int i2c_class)
  91 {
  92         int rc;
  93
  94         strcpy(chan->adapter.name, name);
  95         chan->adapter.owner             = THIS_MODULE;
  96         chan->adapter.class             = i2c_class;
  97         chan->adapter.algo_data         = &chan->algo;
  98         chan->adapter.dev.parent        = &chan->par->pdev->dev;
  99         chan->algo.setsda               = riva_gpio_setsda;
 100         chan->algo.setscl               = riva_gpio_setscl;
 101         chan->algo.getsda               = riva_gpio_getsda;
 102         chan->algo.getscl               = riva_gpio_getscl;
 103         chan->algo.udelay               = 40;
 104         chan->algo.timeout              = msecs_to_jiffies(2);
 105         chan->algo.data                 = chan;
 106
 107         i2c_set_adapdata(&chan->adapter, chan);
 108
 109         /* Raise SCL and SDA */
 110         riva_gpio_setsda(chan, 1);
 111         riva_gpio_setscl(chan, 1);
 112         udelay(20);
 113
 114         rc = i2c_bit_add_bus(&chan->adapter);
 115         if (rc == 0)
 116                 dev_dbg(&chan->par->pdev->dev, "I2C bus %s registered.\n", name);
 117         else {
 118                 dev_warn(&chan->par->pdev->dev,
 119                          "Failed to register I2C bus %s.\n", name);
 120                 chan->par = NULL;
 121         }
 122
 123         return rc;
 124 }
 125
 126 void riva_create_i2c_busses(struct riva_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 = 0x36;
 133         par->chan[1].ddc_base = 0x3e;
 134         par->chan[2].ddc_base = 0x50;
 135         riva_setup_i2c_bus(&par->chan[0], "BUS1", I2C_CLASS_HWMON);
 136         riva_setup_i2c_bus(&par->chan[1], "BUS2", 0);
 137         riva_setup_i2c_bus(&par->chan[2], "BUS3", 0);
 138 }
 139
 140 void riva_delete_i2c_busses(struct riva_par *par)
 141 {
 142         int i;
 143
 144         for (i = 0; i < 3; i++) {
 145                 if (!par->chan[i].par)
 146                         continue;
 147                 i2c_del_adapter(&par->chan[i].adapter);
 148                 par->chan[i].par = NULL;
 149         }
 150 }
 151
 152 int riva_probe_i2c_connector(struct riva_par *par, int conn, u8 **out_edid)
 153 {
 154         u8 *edid = NULL;
 155
 156         if (par->chan[conn].par)
 157                 edid = fb_ddc_read(&par->chan[conn].adapter);
 158
 159         if (out_edid)
 160                 *out_edid = edid;
 161         if (!edid)
 162                 return 1;
 163
 164         return 0;
 165 }
 166