linux-sg2042/drivers/gpu/drm/mgag200/mgag200_i2c.c

157 lines
3.9 KiB
C

/*
* Copyright 2012 Red Hat Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sub license, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
* USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
*/
/*
* Authors: Dave Airlie <airlied@redhat.com>
*/
#include <linux/export.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-bit.h>
#include <drm/drmP.h>
#include "mgag200_drv.h"
static int mga_i2c_read_gpio(struct mga_device *mdev)
{
WREG8(DAC_INDEX, MGA1064_GEN_IO_DATA);
return RREG8(DAC_DATA);
}
static void mga_i2c_set_gpio(struct mga_device *mdev, int mask, int val)
{
int tmp;
WREG8(DAC_INDEX, MGA1064_GEN_IO_CTL);
tmp = (RREG8(DAC_DATA) & mask) | val;
WREG_DAC(MGA1064_GEN_IO_CTL, tmp);
WREG_DAC(MGA1064_GEN_IO_DATA, 0);
}
static inline void mga_i2c_set(struct mga_device *mdev, int mask, int state)
{
if (state)
state = 0;
else
state = mask;
mga_i2c_set_gpio(mdev, ~mask, state);
}
static void mga_gpio_setsda(void *data, int state)
{
struct mga_i2c_chan *i2c = data;
struct mga_device *mdev = i2c->dev->dev_private;
mga_i2c_set(mdev, i2c->data, state);
}
static void mga_gpio_setscl(void *data, int state)
{
struct mga_i2c_chan *i2c = data;
struct mga_device *mdev = i2c->dev->dev_private;
mga_i2c_set(mdev, i2c->clock, state);
}
static int mga_gpio_getsda(void *data)
{
struct mga_i2c_chan *i2c = data;
struct mga_device *mdev = i2c->dev->dev_private;
return (mga_i2c_read_gpio(mdev) & i2c->data) ? 1 : 0;
}
static int mga_gpio_getscl(void *data)
{
struct mga_i2c_chan *i2c = data;
struct mga_device *mdev = i2c->dev->dev_private;
return (mga_i2c_read_gpio(mdev) & i2c->clock) ? 1 : 0;
}
struct mga_i2c_chan *mgag200_i2c_create(struct drm_device *dev)
{
struct mga_device *mdev = dev->dev_private;
struct mga_i2c_chan *i2c;
int ret;
int data, clock;
WREG_DAC(MGA1064_GEN_IO_CTL2, 1);
WREG_DAC(MGA1064_GEN_IO_DATA, 0xff);
WREG_DAC(MGA1064_GEN_IO_CTL, 0);
switch (mdev->type) {
case G200_SE_A:
case G200_SE_B:
case G200_EV:
case G200_WB:
data = 1;
clock = 2;
break;
case G200_EH:
case G200_ER:
data = 2;
clock = 1;
break;
default:
data = 2;
clock = 8;
break;
}
i2c = kzalloc(sizeof(struct mga_i2c_chan), GFP_KERNEL);
if (!i2c)
return NULL;
i2c->data = data;
i2c->clock = clock;
i2c->adapter.owner = THIS_MODULE;
i2c->adapter.class = I2C_CLASS_DDC;
i2c->adapter.dev.parent = &dev->pdev->dev;
i2c->dev = dev;
i2c_set_adapdata(&i2c->adapter, i2c);
snprintf(i2c->adapter.name, sizeof(i2c->adapter.name), "mga i2c");
i2c->adapter.algo_data = &i2c->bit;
i2c->bit.udelay = 10;
i2c->bit.timeout = 2;
i2c->bit.data = i2c;
i2c->bit.setsda = mga_gpio_setsda;
i2c->bit.setscl = mga_gpio_setscl;
i2c->bit.getsda = mga_gpio_getsda;
i2c->bit.getscl = mga_gpio_getscl;
ret = i2c_bit_add_bus(&i2c->adapter);
if (ret) {
kfree(i2c);
i2c = NULL;
}
return i2c;
}
void mgag200_i2c_destroy(struct mga_i2c_chan *i2c)
{
if (!i2c)
return;
i2c_del_adapter(&i2c->adapter);
kfree(i2c);
}