drivers/video/fbdev/riva/rivafb-i2c.c

Source file repositories/reference/linux-study-clean/drivers/video/fbdev/riva/rivafb-i2c.c

File Facts

System
Linux kernel
Corpus path
drivers/video/fbdev/riva/rivafb-i2c.c
Extension
.c
Size
3690 bytes
Lines
167
Domain
Driver Families
Bucket
drivers/video
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/pci.h>
#include <linux/fb.h>
#include <linux/jiffies.h>

#include <asm/io.h>

#include "rivafb.h"
#include "../edid.h"

static void riva_gpio_setscl(void* data, int state)
{
	struct riva_i2c_chan 	*chan = data;
	struct riva_par 	*par = chan->par;
	u32			val;

	VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base + 1);
	val = VGA_RD08(par->riva.PCIO, 0x3d5) & 0xf0;

	if (state)
		val |= 0x20;
	else
		val &= ~0x20;

	VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base + 1);
	VGA_WR08(par->riva.PCIO, 0x3d5, val | 0x1);
}

static void riva_gpio_setsda(void* data, int state)
{
	struct riva_i2c_chan 	*chan = data;
	struct riva_par 	*par = chan->par;
	u32			val;

	VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base + 1);
	val = VGA_RD08(par->riva.PCIO, 0x3d5) & 0xf0;

	if (state)
		val |= 0x10;
	else
		val &= ~0x10;

	VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base + 1);
	VGA_WR08(par->riva.PCIO, 0x3d5, val | 0x1);
}

static int riva_gpio_getscl(void* data)
{
	struct riva_i2c_chan 	*chan = data;
	struct riva_par 	*par = chan->par;
	u32			val = 0;

	VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base);
	if (VGA_RD08(par->riva.PCIO, 0x3d5) & 0x04)
		val = 1;

	return val;
}

static int riva_gpio_getsda(void* data)
{
	struct riva_i2c_chan 	*chan = data;
	struct riva_par 	*par = chan->par;
	u32			val = 0;

	VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base);
	if (VGA_RD08(par->riva.PCIO, 0x3d5) & 0x08)
		val = 1;

	return val;
}

static int riva_setup_i2c_bus(struct riva_i2c_chan *chan, const char *name,
			      unsigned int i2c_class)
{
	int rc;

	strscpy(chan->adapter.name, name);
	chan->adapter.owner		= THIS_MODULE;
	chan->adapter.class		= i2c_class;
	chan->adapter.algo_data		= &chan->algo;
	chan->adapter.dev.parent	= &chan->par->pdev->dev;
	chan->algo.setsda		= riva_gpio_setsda;
	chan->algo.setscl		= riva_gpio_setscl;
	chan->algo.getsda		= riva_gpio_getsda;
	chan->algo.getscl		= riva_gpio_getscl;
	chan->algo.udelay		= 40;
	chan->algo.timeout		= msecs_to_jiffies(2);

Annotation

Implementation Notes