linux/drivers/video/fbdev/nvidia/nv_i2c.c
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   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
  28static 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
  44static 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
  60static 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
  72static 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
  84static 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
 122void 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
 140void 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
 152int 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}
 172