linux_dsm_epyc7002/drivers/gpu/drm/gma500/intel_i2c.c
Thomas Gleixner a61127c213 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 335
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation this program
  is distributed in the hope it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not write to the free
  software foundation inc 51 franklin st fifth floor boston ma 02110
  1301 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 111 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000436.567572064@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:37:06 +02:00

158 lines
3.7 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright © 2006-2007 Intel Corporation
*
* Authors:
* Eric Anholt <eric@anholt.net>
*/
#include <linux/export.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-bit.h>
#include "psb_drv.h"
#include "psb_intel_reg.h"
/*
* Intel GPIO access functions
*/
#define I2C_RISEFALL_TIME 20
static int get_clock(void *data)
{
struct psb_intel_i2c_chan *chan = data;
struct drm_device *dev = chan->drm_dev;
u32 val;
val = REG_READ(chan->reg);
return (val & GPIO_CLOCK_VAL_IN) != 0;
}
static int get_data(void *data)
{
struct psb_intel_i2c_chan *chan = data;
struct drm_device *dev = chan->drm_dev;
u32 val;
val = REG_READ(chan->reg);
return (val & GPIO_DATA_VAL_IN) != 0;
}
static void set_clock(void *data, int state_high)
{
struct psb_intel_i2c_chan *chan = data;
struct drm_device *dev = chan->drm_dev;
u32 reserved = 0, clock_bits;
/* On most chips, these bits must be preserved in software. */
reserved =
REG_READ(chan->reg) & (GPIO_DATA_PULLUP_DISABLE |
GPIO_CLOCK_PULLUP_DISABLE);
if (state_high)
clock_bits = GPIO_CLOCK_DIR_IN | GPIO_CLOCK_DIR_MASK;
else
clock_bits = GPIO_CLOCK_DIR_OUT | GPIO_CLOCK_DIR_MASK |
GPIO_CLOCK_VAL_MASK;
REG_WRITE(chan->reg, reserved | clock_bits);
udelay(I2C_RISEFALL_TIME); /* wait for the line to change state */
}
static void set_data(void *data, int state_high)
{
struct psb_intel_i2c_chan *chan = data;
struct drm_device *dev = chan->drm_dev;
u32 reserved = 0, data_bits;
/* On most chips, these bits must be preserved in software. */
reserved =
REG_READ(chan->reg) & (GPIO_DATA_PULLUP_DISABLE |
GPIO_CLOCK_PULLUP_DISABLE);
if (state_high)
data_bits = GPIO_DATA_DIR_IN | GPIO_DATA_DIR_MASK;
else
data_bits =
GPIO_DATA_DIR_OUT | GPIO_DATA_DIR_MASK |
GPIO_DATA_VAL_MASK;
REG_WRITE(chan->reg, reserved | data_bits);
udelay(I2C_RISEFALL_TIME); /* wait for the line to change state */
}
/**
* psb_intel_i2c_create - instantiate an Intel i2c bus using the specified GPIO reg
* @dev: DRM device
* @output: driver specific output device
* @reg: GPIO reg to use
* @name: name for this bus
*
* Creates and registers a new i2c bus with the Linux i2c layer, for use
* in output probing and control (e.g. DDC or SDVO control functions).
*
* Possible values for @reg include:
* %GPIOA
* %GPIOB
* %GPIOC
* %GPIOD
* %GPIOE
* %GPIOF
* %GPIOG
* %GPIOH
* see PRM for details on how these different busses are used.
*/
struct psb_intel_i2c_chan *psb_intel_i2c_create(struct drm_device *dev,
const u32 reg, const char *name)
{
struct psb_intel_i2c_chan *chan;
chan = kzalloc(sizeof(struct psb_intel_i2c_chan), GFP_KERNEL);
if (!chan)
goto out_free;
chan->drm_dev = dev;
chan->reg = reg;
snprintf(chan->adapter.name, I2C_NAME_SIZE, "intel drm %s", name);
chan->adapter.owner = THIS_MODULE;
chan->adapter.algo_data = &chan->algo;
chan->adapter.dev.parent = &dev->pdev->dev;
chan->algo.setsda = set_data;
chan->algo.setscl = set_clock;
chan->algo.getsda = get_data;
chan->algo.getscl = get_clock;
chan->algo.udelay = 20;
chan->algo.timeout = usecs_to_jiffies(2200);
chan->algo.data = chan;
i2c_set_adapdata(&chan->adapter, chan);
if (i2c_bit_add_bus(&chan->adapter))
goto out_free;
/* JJJ: raise SCL and SDA? */
set_data(chan, 1);
set_clock(chan, 1);
udelay(20);
return chan;
out_free:
kfree(chan);
return NULL;
}
/**
* psb_intel_i2c_destroy - unregister and free i2c bus resources
* @output: channel to free
*
* Unregister the adapter from the i2c layer, then free the structure.
*/
void psb_intel_i2c_destroy(struct psb_intel_i2c_chan *chan)
{
if (!chan)
return;
i2c_del_adapter(&chan->adapter);
kfree(chan);
}