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/gfp.h>
  17 #include <linux/pci.h>
  18 #include <linux/fb.h>
  19
  20 #include <asm/io.h>
  21
  22 #include "nv_type.h"
  23 #include "nv_local.h"
  24 #include "nv_proto.h"
  25
  26 #include "../edid.h"
  27
  28 static void nvidia_gpio_setscl(void *data, int state)
  29 {
  30         struct nvidia_i2c_chan *chan = data;
  31         struct nvidia_par *par = chan->par;
  32         u32 val;
  33
  34         val = NVReadCrtc(par, chan->ddc_base + 1) & 0xf0;
  35
  36         if (state)
  37                 val |= 0x20;
  38         else
  39                 val &= ~0x20;
  40
  41         NVWriteCrtc(par, chan->ddc_base + 1, val | 0x01);
  42 }
  43
  44 static void nvidia_gpio_setsda(void *data, int state)
  45 {
  46         struct nvidia_i2c_chan *chan = data;
  47         struct nvidia_par *par = chan->par;
  48         u32 val;
  49
  50         val = NVReadCrtc(par, chan->ddc_base + 1) & 0xf0;
  51
  52         if (state)
  53                 val |= 0x10;
  54         else
  55                 val &= ~0x10;
  56
  57         NVWriteCrtc(par, chan->ddc_base + 1, val | 0x01);
  58 }
  59
  60 static int nvidia_gpio_getscl(void *data)
  61 {
  62         struct nvidia_i2c_chan *chan = data;
  63         struct nvidia_par *par = chan->par;
  64         u32 val = 0;
  65
  66         if (NVReadCrtc(par, chan->ddc_base) & 0x04)
  67                 val = 1;
  68
  69         return val;
  70 }
  71
  72 static int nvidia_gpio_getsda(void *data)
  73 {
  74         struct nvidia_i2c_chan *chan = data;
  75         struct nvidia_par *par = chan->par;
  76         u32 val = 0;
  77
  78         if (NVReadCrtc(par, chan->ddc_base) & 0x08)
  79                 val = 1;
  80
  81         return val;
  82 }
  83
  84 static int nvidia_setup_i2c_bus(struct nvidia_i2c_chan *chan, const char *name,
  85                                 unsigned int i2c_class)
  86 {
  87         int rc;
  88
  89         strcpy(chan->adapter.name, name);
  90         chan->adapter.owner = THIS_MODULE;
  91         chan->adapter.class = i2c_class;
  92         chan->adapter.algo_data = &chan->algo;
  93         chan->adapter.dev.parent = &chan->par->pci_dev->dev;
  94         chan->algo.setsda = nvidia_gpio_setsda;
  95         chan->algo.setscl = nvidia_gpio_setscl;
  96         chan->algo.getsda = nvidia_gpio_getsda;
  97         chan->algo.getscl = nvidia_gpio_getscl;
  98         chan->algo.udelay = 40;
  99         chan->algo.timeout = msecs_to_jiffies(2);
 100         chan->algo.data = chan;
 101
 102         i2c_set_adapdata(&chan->adapter, chan);
 103
 104         /* Raise SCL and SDA */
 105         nvidia_gpio_setsda(chan, 1);
 106         nvidia_gpio_setscl(chan, 1);
 107         udelay(20);
 108
 109         rc = i2c_bit_add_bus(&chan->adapter);
 110         if (rc == 0)
 111                 dev_dbg(&chan->par->pci_dev->dev,
 112                         "I2C bus %s registered.\n", name);
 113         else {
 114                 dev_warn(&chan->par->pci_dev->dev,
 115                          "Failed to register I2C bus %s.\n", name);
 116                 chan->par = NULL;
 117         }
 118
 119         return rc;
 120 }
 121
 122 void nvidia_create_i2c_busses(struct nvidia_par *par)
 123 {
 124         par->chan[0].par = par;
 125         par->chan[1].par = par;
 126         par->chan[2].par = par;
 127
 128         par->chan[0].ddc_base = (par->reverse_i2c) ? 0x36 : 0x3e;
 129         nvidia_setup_i2c_bus(&par->chan[0], "nvidia #0",
 130                              (par->reverse_i2c) ? I2C_CLASS_HWMON : 0);
 131
 132         par->chan[1].ddc_base = (par->reverse_i2c) ? 0x3e : 0x36;
 133         nvidia_setup_i2c_bus(&par->chan[1], "nvidia #1",
 134                              (par->reverse_i2c) ? 0 : I2C_CLASS_HWMON);
 135
 136         par->chan[2].ddc_base = 0x50;
 137         nvidia_setup_i2c_bus(&par->chan[2], "nvidia #2", 0);
 138 }
 139
 140 void nvidia_delete_i2c_busses(struct nvidia_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 nvidia_probe_i2c_connector(struct fb_info *info, int conn, u8 **out_edid)
 153 {
 154         struct nvidia_par *par = info->par;
 155         u8 *edid = NULL;
 156
 157         if (par->chan[conn - 1].par)
 158                 edid = fb_ddc_read(&par->chan[conn - 1].adapter);
 159
 160         if (!edid && conn == 1) {
 161                 /* try to get from firmware */
 162                 const u8 *e = fb_firmware_edid(info->device);
 163
 164                 if (e != NULL)
 165                         edid = kmemdup(e, EDID_LENGTH, GFP_KERNEL);
 166         }
 167
 168         *out_edid = edid;
 169
 170         return (edid) ? 0 : 1;
 171 }