LXR linux/drivers/gpu/drm/mgag200/mgag200

   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
  35static 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
  41static 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
  51static 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
  60static 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
  67static 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
  74static 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
  81static 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
  88struct 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
 149void 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
 157