drivers/video/nvidia/nv_i2c.c

   1 /*
   2  * linux/drivers/video/nvidia/nvidia-i2c.c - nVidia i2c
   3  *
   4  * Copyright 2004 Antonino A. Daplas <adaplas @pol.net>
   5  *
   6  * Based on rivafb-i2c.c
   7  *
   8  * This file is subject to the terms and conditions of the GNU General Public
   9  * License.  See the file COPYING in the main directory of this archive
  10  * for more details.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/kernel.h>
  15 #include <linux/delay.h>
  16 #include <linux/pci.h>
  17 #include <linux/fb.h>
  18
  19 #include <asm/io.h>
  20
  21 #include "nv_type.h"
  22 #include "nv_local.h"
  23 #include "nv_proto.h"
  24
  25 #include "../edid.h"
  26
  27 static void nvidia_gpio_setscl(void *data, int state)
  28 {
  29         struct nvidia_i2c_chan *chan = data;
  30         struct nvidia_par *par = chan->par;
  31         u32 val;
  32
  33         val = NVReadCrtc(par, chan->ddc_base + 1) & 0xf0;
  34
  35         if (state)
  36                 val |= 0x20;
  37         else
  38                 val &= ~0x20;
  39
  40         NVWriteCrtc(par, chan->ddc_base + 1, val | 0x01);
  41 }
  42
  43 static void nvidia_gpio_setsda(void *data, int state)
  44 {
  45         struct nvidia_i2c_chan *chan = data;
  46         struct nvidia_par *par = chan->par;
  47         u32 val;
  48
  49         val = NVReadCrtc(par, chan->ddc_base + 1) & 0xf0;
  50
  51         if (state)
  52                 val |= 0x10;
  53         else
  54                 val &= ~0x10;
  55
  56         NVWriteCrtc(par, chan->ddc_base + 1, val | 0x01);
  57 }
  58
  59 static int nvidia_gpio_getscl(void *data)
  60 {
  61         struct nvidia_i2c_chan *chan = data;
  62         struct nvidia_par *par = chan->par;
  63         u32 val = 0;
  64
  65         if (NVReadCrtc(par, chan->ddc_base) & 0x04)
  66                 val = 1;
  67
  68         return val;
  69 }
  70
  71 static int nvidia_gpio_getsda(void *data)
  72 {
  73         struct nvidia_i2c_chan *chan = data;
  74         struct nvidia_par *par = chan->par;
  75         u32 val = 0;
  76
  77         if (NVReadCrtc(par, chan->ddc_base) & 0x08)
  78                 val = 1;
  79
  80         return val;
  81 }
  82
  83 static int nvidia_setup_i2c_bus(struct nvidia_i2c_chan *chan, const char *name,
  84                                 unsigned int i2c_class)
  85 {
  86         int rc;
  87
  88         strcpy(chan->adapter.name, name);
  89         chan->adapter.owner = THIS_MODULE;
  90         chan->adapter.class = i2c_class;
  91         chan->adapter.algo_data = &chan->algo;
  92         chan->adapter.dev.parent = &chan->par->pci_dev->dev;
  93         chan->algo.setsda = nvidia_gpio_setsda;
  94         chan->algo.setscl = nvidia_gpio_setscl;
  95         chan->algo.getsda = nvidia_gpio_getsda;
  96         chan->algo.getscl = nvidia_gpio_getscl;
  97         chan->algo.udelay = 40;
  98         chan->algo.timeout = msecs_to_jiffies(2);
  99         chan->algo.data = chan;
 100
 101         i2c_set_adapdata(&chan->adapter, chan);
 102
 103         /* Raise SCL and SDA */
 104         nvidia_gpio_setsda(chan, 1);
 105         nvidia_gpio_setscl(chan, 1);
 106         udelay(20);
 107
 108         rc = i2c_bit_add_bus(&chan->adapter);
 109         if (rc == 0)
 110                 dev_dbg(&chan->par->pci_dev->dev,
 111                         "I2C bus %s registered.\n", name);
 112         else {
 113                 dev_warn(&chan->par->pci_dev->dev,
 114                          "Failed to register I2C bus %s.\n", name);
 115                 chan->par = NULL;
 116         }
 117
 118         return rc;
 119 }
 120
 121 void nvidia_create_i2c_busses(struct nvidia_par *par)
 122 {
 123         par->chan[0].par = par;
 124         par->chan[1].par = par;
 125         par->chan[2].par = par;
 126
 127         par->chan[0].ddc_base = (par->reverse_i2c) ? 0x36 : 0x3e;
 128         nvidia_setup_i2c_bus(&par->chan[0], "nvidia #0",
 129                              (par->reverse_i2c) ? I2C_CLASS_HWMON : 0);
 130
 131         par->chan[1].ddc_base = (par->reverse_i2c) ? 0x3e : 0x36;
 132         nvidia_setup_i2c_bus(&par->chan[1], "nvidia #1",
 133                              (par->reverse_i2c) ? 0 : I2C_CLASS_HWMON);
 134
 135         par->chan[2].ddc_base = 0x50;
 136         nvidia_setup_i2c_bus(&par->chan[2], "nvidia #2", 0);
 137 }
 138
 139 void nvidia_delete_i2c_busses(struct nvidia_par *par)
 140 {
 141         int i;
 142
 143         for (i = 0; i < 3; i++) {
 144                 if (!par->chan[i].par)
 145                         continue;
 146                 i2c_del_adapter(&par->chan[i].adapter);
 147                 par->chan[i].par = NULL;
 148         }
 149 }
 150
 151 int nvidia_probe_i2c_connector(struct fb_info *info, int conn, u8 **out_edid)
 152 {
 153         struct nvidia_par *par = info->par;
 154         u8 *edid = NULL;
 155
 156         if (par->chan[conn - 1].par)
 157                 edid = fb_ddc_read(&par->chan[conn - 1].adapter);
 158
 159         if (!edid && conn == 1) {
 160                 /* try to get from firmware */
 161                 const u8 *e = fb_firmware_edid(info->device);
 162
 163                 if (e != NULL)
 164                         edid = kmemdup(e, EDID_LENGTH, GFP_KERNEL);
 165         }
 166
 167         *out_edid = edid;
 168
 169         return (edid) ? 0 : 1;
 170 }