drivers/gpu/drm/mgag200/mgag200_i2c.c

   1 /*
   2  * Copyright 2012 Red Hat Inc.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the
   6  * "Software"), to deal in the Software without restriction, including
   7  * without limitation the rights to use, copy, modify, merge, publish,
   8  * distribute, sub license, and/or sell copies of the Software, and to
   9  * permit persons to whom the Software is furnished to do so, subject to
  10  * the following conditions:
  11  *
  12  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  13  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  14  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  15  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  16  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  17  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  18  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  19  *
  20  * The above copyright notice and this permission notice (including the
  21  * next paragraph) shall be included in all copies or substantial portions
  22  * of the Software.
  23  *
  24  */
  25 /*
  26  * Authors: Dave Airlie <airlied@redhat.com>
  27  */
  28
  29 #include <linux/export.h>
  30 #include <linux/i2c-algo-bit.h>
  31 #include <linux/i2c.h>
  32 #include <linux/pci.h>
  33
  34 #include "mgag200_drv.h"
  35
  36 static int mga_i2c_read_gpio(struct mga_device *mdev)
  37 {
  38         WREG8(DAC_INDEX, MGA1064_GEN_IO_DATA);
  39         return RREG8(DAC_DATA);
  40 }
  41
  42 static void mga_i2c_set_gpio(struct mga_device *mdev, int mask, int val)
  43 {
  44         int tmp;
  45
  46         WREG8(DAC_INDEX, MGA1064_GEN_IO_CTL);
  47         tmp = (RREG8(DAC_DATA) & mask) | val;
  48         WREG_DAC(MGA1064_GEN_IO_CTL, tmp);
  49         WREG_DAC(MGA1064_GEN_IO_DATA, 0);
  50 }
  51
  52 static inline void mga_i2c_set(struct mga_device *mdev, int mask, int state)
  53 {
  54         if (state)
  55                 state = 0;
  56         else
  57                 state = mask;
  58         mga_i2c_set_gpio(mdev, ~mask, state);
  59 }
  60
  61 static void mga_gpio_setsda(void *data, int state)
  62 {
  63         struct mga_i2c_chan *i2c = data;
  64         struct mga_device *mdev = to_mga_device(i2c->dev);
  65         mga_i2c_set(mdev, i2c->data, state);
  66 }
  67
  68 static void mga_gpio_setscl(void *data, int state)
  69 {
  70         struct mga_i2c_chan *i2c = data;
  71         struct mga_device *mdev = to_mga_device(i2c->dev);
  72         mga_i2c_set(mdev, i2c->clock, state);
  73 }
  74
  75 static int mga_gpio_getsda(void *data)
  76 {
  77         struct mga_i2c_chan *i2c = data;
  78         struct mga_device *mdev = to_mga_device(i2c->dev);
  79         return (mga_i2c_read_gpio(mdev) & i2c->data) ? 1 : 0;
  80 }
  81
  82 static int mga_gpio_getscl(void *data)
  83 {
  84         struct mga_i2c_chan *i2c = data;
  85         struct mga_device *mdev = to_mga_device(i2c->dev);
  86         return (mga_i2c_read_gpio(mdev) & i2c->clock) ? 1 : 0;
  87 }
  88
  89 struct mga_i2c_chan *mgag200_i2c_create(struct drm_device *dev)
  90 {
  91         struct mga_device *mdev = to_mga_device(dev);
  92         struct mga_i2c_chan *i2c;
  93         int ret;
  94         int data, clock;
  95
  96         WREG_DAC(MGA1064_GEN_IO_CTL2, 1);
  97         WREG_DAC(MGA1064_GEN_IO_DATA, 0xff);
  98         WREG_DAC(MGA1064_GEN_IO_CTL, 0);
  99
 100         switch (mdev->type) {
 101         case G200_SE_A:
 102         case G200_SE_B:
 103         case G200_EV:
 104         case G200_WB:
 105         case G200_EW3:
 106                 data = 1;
 107                 clock = 2;
 108                 break;
 109         case G200_EH:
 110         case G200_EH3:
 111         case G200_ER:
 112                 data = 2;
 113                 clock = 1;
 114                 break;
 115         default:
 116                 data = 2;
 117                 clock = 8;
 118                 break;
 119         }
 120
 121         i2c = kzalloc(sizeof(struct mga_i2c_chan), GFP_KERNEL);
 122         if (!i2c)
 123                 return NULL;
 124
 125         i2c->data = data;
 126         i2c->clock = clock;
 127         i2c->adapter.owner = THIS_MODULE;
 128         i2c->adapter.class = I2C_CLASS_DDC;
 129         i2c->adapter.dev.parent = &dev->pdev->dev;
 130         i2c->dev = dev;
 131         i2c_set_adapdata(&i2c->adapter, i2c);
 132         snprintf(i2c->adapter.name, sizeof(i2c->adapter.name), "mga i2c");
 133
 134         i2c->adapter.algo_data = &i2c->bit;
 135
 136         i2c->bit.udelay = 10;
 137         i2c->bit.timeout = 2;
 138         i2c->bit.data = i2c;
 139         i2c->bit.setsda         = mga_gpio_setsda;
 140         i2c->bit.setscl         = mga_gpio_setscl;
 141         i2c->bit.getsda         = mga_gpio_getsda;
 142         i2c->bit.getscl         = mga_gpio_getscl;
 143
 144         ret = i2c_bit_add_bus(&i2c->adapter);
 145         if (ret) {
 146                 kfree(i2c);
 147                 i2c = NULL;
 148         }
 149         return i2c;
 150 }
 151
 152 void mgag200_i2c_destroy(struct mga_i2c_chan *i2c)
 153 {
 154         if (!i2c)
 155                 return;
 156         i2c_del_adapter(&i2c->adapter);
 157         kfree(i2c);
 158 }
 159