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 #include <linux/export.h>
  29 #include <linux/i2c.h>
  30 #include <linux/i2c-algo-bit.h>
  31 #include <drm/drmP.h>
  32
  33 #include "mgag200_drv.h"
  34
  35 static int mga_i2c_read_gpio(struct mga_device *mdev)
  36 {
  37         WREG8(DAC_INDEX, MGA1064_GEN_IO_DATA);
  38         return RREG8(DAC_DATA);
  39 }
  40
  41 static void mga_i2c_set_gpio(struct mga_device *mdev, int mask, int val)
  42 {
  43         int tmp;
  44
  45         WREG8(DAC_INDEX, MGA1064_GEN_IO_CTL);
  46         tmp = (RREG8(DAC_DATA) & mask) | val;
  47         WREG_DAC(MGA1064_GEN_IO_CTL, tmp);
  48         WREG_DAC(MGA1064_GEN_IO_DATA, 0);
  49 }
  50
  51 static inline void mga_i2c_set(struct mga_device *mdev, int mask, int state)
  52 {
  53         if (state)
  54                 state = 0;
  55         else
  56                 state = mask;
  57         mga_i2c_set_gpio(mdev, ~mask, state);
  58 }
  59
  60 static void mga_gpio_setsda(void *data, int state)
  61 {
  62         struct mga_i2c_chan *i2c = data;
  63         struct mga_device *mdev = i2c->dev->dev_private;
  64         mga_i2c_set(mdev, i2c->data, state);
  65 }
  66
  67 static void mga_gpio_setscl(void *data, int state)
  68 {
  69         struct mga_i2c_chan *i2c = data;
  70         struct mga_device *mdev = i2c->dev->dev_private;
  71         mga_i2c_set(mdev, i2c->clock, state);
  72 }
  73
  74 static int mga_gpio_getsda(void *data)
  75 {
  76         struct mga_i2c_chan *i2c = data;
  77         struct mga_device *mdev = i2c->dev->dev_private;
  78         return (mga_i2c_read_gpio(mdev) & i2c->data) ? 1 : 0;
  79 }
  80
  81 static int mga_gpio_getscl(void *data)
  82 {
  83         struct mga_i2c_chan *i2c = data;
  84         struct mga_device *mdev = i2c->dev->dev_private;
  85         return (mga_i2c_read_gpio(mdev) & i2c->clock) ? 1 : 0;
  86 }
  87
  88 struct mga_i2c_chan *mgag200_i2c_create(struct drm_device *dev)
  89 {
  90         struct mga_device *mdev = dev->dev_private;
  91         struct mga_i2c_chan *i2c;
  92         int ret;
  93         int data, clock;
  94
  95         WREG_DAC(MGA1064_GEN_IO_CTL2, 1);
  96         WREG_DAC(MGA1064_GEN_IO_DATA, 0xff);
  97         WREG_DAC(MGA1064_GEN_IO_CTL, 0);
  98
  99         switch (mdev->type) {
 100         case G200_SE_A:
 101         case G200_SE_B:
 102         case G200_EV:
 103         case G200_WB:
 104                 data = 1;
 105                 clock = 2;
 106                 break;
 107         case G200_EH:
 108         case G200_ER:
 109                 data = 2;
 110                 clock = 1;
 111                 break;
 112         default:
 113                 data = 2;
 114                 clock = 8;
 115                 break;
 116         }
 117
 118         i2c = kzalloc(sizeof(struct mga_i2c_chan), GFP_KERNEL);
 119         if (!i2c)
 120                 return NULL;
 121
 122         i2c->data = data;
 123         i2c->clock = clock;
 124         i2c->adapter.owner = THIS_MODULE;
 125         i2c->adapter.class = I2C_CLASS_DDC;
 126         i2c->adapter.dev.parent = &dev->pdev->dev;
 127         i2c->dev = dev;
 128         i2c_set_adapdata(&i2c->adapter, i2c);
 129         snprintf(i2c->adapter.name, sizeof(i2c->adapter.name), "mga i2c");
 130
 131         i2c->adapter.algo_data = &i2c->bit;
 132
 133         i2c->bit.udelay = 10;
 134         i2c->bit.timeout = 2;
 135         i2c->bit.data = i2c;
 136         i2c->bit.setsda         = mga_gpio_setsda;
 137         i2c->bit.setscl         = mga_gpio_setscl;
 138         i2c->bit.getsda         = mga_gpio_getsda;
 139         i2c->bit.getscl         = mga_gpio_getscl;
 140
 141         ret = i2c_bit_add_bus(&i2c->adapter);
 142         if (ret) {
 143                 kfree(i2c);
 144                 i2c = NULL;
 145         }
 146         return i2c;
 147 }
 148
 149 void mgag200_i2c_destroy(struct mga_i2c_chan *i2c)
 150 {
 151         if (!i2c)
 152                 return;
 153         i2c_del_adapter(&i2c->adapter);
 154         kfree(i2c);
 155 }
 156