[linux-2.6-block.git] / drivers / gpu / drm / gma500 / intel_i2c.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright © 2006-2007 Intel Corporation
 *
 * Authors:
 *	Eric Anholt <eric@anholt.net>
 */

#include <linux/delay.h>
#include <linux/export.h>
#include <linux/i2c-algo-bit.h>
#include <linux/i2c.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 gma_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 gma_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 gma_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 gma_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 */
}

/**
 * gma_i2c_create - instantiate an Intel i2c bus using the specified GPIO reg
 * @dev: DRM 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 gma_i2c_chan *gma_i2c_create(struct drm_device *dev, const u32 reg,
				    const char *name)
{
	struct gma_i2c_chan *chan;

	chan = kzalloc(sizeof(struct gma_i2c_chan), GFP_KERNEL);
	if (!chan)
		goto out_free;

	chan->drm_dev = dev;
	chan->reg = reg;
	snprintf(chan->base.name, I2C_NAME_SIZE, "intel drm %s", name);
	chan->base.owner = THIS_MODULE;
	chan->base.algo_data = &chan->algo;
	chan->base.dev.parent = dev->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->base, chan);

	if (i2c_bit_add_bus(&chan->base))
		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;
}

/**
 * gma_i2c_destroy - unregister and free i2c bus resources
 * @chan: channel to free
 *
 * Unregister the adapter from the i2c layer, then free the structure.
 */
void gma_i2c_destroy(struct gma_i2c_chan *chan)
{
	if (!chan)
		return;

	i2c_del_adapter(&chan->base);
	kfree(chan);
}
Commit	Line	Data
a61127c2	1	// SPDX-License-Identifier: GPL-2.0-only
5091b7eb AC	2	/*
	3	* Copyright © 2006-2007 Intel Corporation
	4	*
5091b7eb AC	5	* Authors:
	6	* Eric Anholt <eric@anholt.net>
	7	*/
0c7b178a	8
51474335	9	#include <linux/delay.h>
af3a2cfb	10	#include <linux/export.h>
5091b7eb	11	#include <linux/i2c-algo-bit.h>
51474335	12	#include <linux/i2c.h>
5091b7eb AC	13
	14	#include "psb_drv.h"
	15	#include "psb_intel_reg.h"
	16
	17	/*
	18	* Intel GPIO access functions
	19	*/
	20
	21	#define I2C_RISEFALL_TIME 20
	22
	23	static int get_clock(void *data)
	24	{
04477e5e	25	struct gma_i2c_chan *chan = data;
5091b7eb AC	26	struct drm_device *dev = chan->drm_dev;
	27	u32 val;
	28
	29	val = REG_READ(chan->reg);
	30	return (val & GPIO_CLOCK_VAL_IN) != 0;
	31	}
	32
	33	static int get_data(void *data)
	34	{
04477e5e	35	struct gma_i2c_chan *chan = data;
5091b7eb AC	36	struct drm_device *dev = chan->drm_dev;
	37	u32 val;
	38
	39	val = REG_READ(chan->reg);
	40	return (val & GPIO_DATA_VAL_IN) != 0;
	41	}
	42
	43	static void set_clock(void *data, int state_high)
	44	{
04477e5e	45	struct gma_i2c_chan *chan = data;
5091b7eb AC	46	struct drm_device *dev = chan->drm_dev;
	47	u32 reserved = 0, clock_bits;
	48
	49	/* On most chips, these bits must be preserved in software. */
	50	reserved =
	51	REG_READ(chan->reg) & (GPIO_DATA_PULLUP_DISABLE \|
	52	GPIO_CLOCK_PULLUP_DISABLE);
	53
	54	if (state_high)
	55	clock_bits = GPIO_CLOCK_DIR_IN \| GPIO_CLOCK_DIR_MASK;
	56	else
	57	clock_bits = GPIO_CLOCK_DIR_OUT \| GPIO_CLOCK_DIR_MASK \|
	58	GPIO_CLOCK_VAL_MASK;
	59	REG_WRITE(chan->reg, reserved \| clock_bits);
	60	udelay(I2C_RISEFALL_TIME); /* wait for the line to change state */
	61	}
	62
	63	static void set_data(void *data, int state_high)
	64	{
04477e5e	65	struct gma_i2c_chan *chan = data;
5091b7eb AC	66	struct drm_device *dev = chan->drm_dev;
	67	u32 reserved = 0, data_bits;
	68
	69	/* On most chips, these bits must be preserved in software. */
	70	reserved =
	71	REG_READ(chan->reg) & (GPIO_DATA_PULLUP_DISABLE \|
	72	GPIO_CLOCK_PULLUP_DISABLE);
	73
	74	if (state_high)
	75	data_bits = GPIO_DATA_DIR_IN \| GPIO_DATA_DIR_MASK;
	76	else
	77	data_bits =
	78	GPIO_DATA_DIR_OUT \| GPIO_DATA_DIR_MASK \|
	79	GPIO_DATA_VAL_MASK;
	80
	81	REG_WRITE(chan->reg, reserved \| data_bits);
	82	udelay(I2C_RISEFALL_TIME); /* wait for the line to change state */
	83	}
	84
	85	/**
04477e5e	86	* gma_i2c_create - instantiate an Intel i2c bus using the specified GPIO reg
5091b7eb	87	* @dev: DRM device
5091b7eb AC	88	* @reg: GPIO reg to use
	89	* @name: name for this bus
	90	*
	91	* Creates and registers a new i2c bus with the Linux i2c layer, for use
	92	* in output probing and control (e.g. DDC or SDVO control functions).
	93	*
	94	* Possible values for @reg include:
	95	* %GPIOA
	96	* %GPIOB
	97	* %GPIOC
	98	* %GPIOD
	99	* %GPIOE
	100	* %GPIOF
	101	* %GPIOG
	102	* %GPIOH
	103	* see PRM for details on how these different busses are used.
	104	*/
04477e5e PJ	105	struct gma_i2c_chan gma_i2c_create(struct drm_device dev, const u32 reg,
04477e5e PJ	106	const char *name)
5091b7eb	107	{
04477e5e	108	struct gma_i2c_chan *chan;
5091b7eb	109
04477e5e	110	chan = kzalloc(sizeof(struct gma_i2c_chan), GFP_KERNEL);
5091b7eb AC	111	if (!chan)
	112	goto out_free;
	113
	114	chan->drm_dev = dev;
	115	chan->reg = reg;
ba1677f7 PJ	116	snprintf(chan->base.name, I2C_NAME_SIZE, "intel drm %s", name);
	117	chan->base.owner = THIS_MODULE;
	118	chan->base.algo_data = &chan->algo;
	119	chan->base.dev.parent = dev->dev;
5091b7eb AC	120	chan->algo.setsda = set_data;
	121	chan->algo.setscl = set_clock;
	122	chan->algo.getsda = get_data;
	123	chan->algo.getscl = get_clock;
	124	chan->algo.udelay = 20;
	125	chan->algo.timeout = usecs_to_jiffies(2200);
	126	chan->algo.data = chan;
	127
ba1677f7	128	i2c_set_adapdata(&chan->base, chan);
5091b7eb	129
ba1677f7	130	if (i2c_bit_add_bus(&chan->base))
5091b7eb AC	131	goto out_free;
	132
	133	/* JJJ: raise SCL and SDA? */
	134	set_data(chan, 1);
	135	set_clock(chan, 1);
	136	udelay(20);
	137
	138	return chan;
	139
	140	out_free:
	141	kfree(chan);
	142	return NULL;
	143	}
	144
	145	/**
04477e5e	146	* gma_i2c_destroy - unregister and free i2c bus resources
93c3ffc8	147	* @chan: channel to free
5091b7eb AC	148	*
	149	* Unregister the adapter from the i2c layer, then free the structure.
	150	*/
04477e5e	151	void gma_i2c_destroy(struct gma_i2c_chan *chan)
5091b7eb AC	152	{
	153	if (!chan)
	154	return;
	155
ba1677f7	156	i2c_del_adapter(&chan->base);
5091b7eb AC	157	kfree(chan);
5091b7eb AC	158	}