drivers/video/fbdev/nvidia/nv_i2c.c

Source file repositories/reference/linux-study-clean/drivers/video/fbdev/nvidia/nv_i2c.c

File Facts

System
Linux kernel
Corpus path
drivers/video/fbdev/nvidia/nv_i2c.c
Extension
.c
Size
3787 bytes
Lines
172
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/gfp.h>
#include <linux/pci.h>
#include <linux/fb.h>

#include <asm/io.h>

#include "nv_type.h"
#include "nv_local.h"
#include "nv_proto.h"

#include "../edid.h"

static void nvidia_gpio_setscl(void *data, int state)
{
	struct nvidia_i2c_chan *chan = data;
	struct nvidia_par *par = chan->par;
	u32 val;

	val = NVReadCrtc(par, chan->ddc_base + 1) & 0xf0;

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

	NVWriteCrtc(par, chan->ddc_base + 1, val | 0x01);
}

static void nvidia_gpio_setsda(void *data, int state)
{
	struct nvidia_i2c_chan *chan = data;
	struct nvidia_par *par = chan->par;
	u32 val;

	val = NVReadCrtc(par, chan->ddc_base + 1) & 0xf0;

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

	NVWriteCrtc(par, chan->ddc_base + 1, val | 0x01);
}

static int nvidia_gpio_getscl(void *data)
{
	struct nvidia_i2c_chan *chan = data;
	struct nvidia_par *par = chan->par;
	u32 val = 0;

	if (NVReadCrtc(par, chan->ddc_base) & 0x04)
		val = 1;

	return val;
}

static int nvidia_gpio_getsda(void *data)
{
	struct nvidia_i2c_chan *chan = data;
	struct nvidia_par *par = chan->par;
	u32 val = 0;

	if (NVReadCrtc(par, chan->ddc_base) & 0x08)
		val = 1;

	return val;
}

static int nvidia_setup_i2c_bus(struct nvidia_i2c_chan *chan, const char *name,
				unsigned int i2c_class)
{
	int rc;

	strscpy(chan->adapter.name, name, sizeof(chan->adapter.name));
	chan->adapter.owner = THIS_MODULE;
	chan->adapter.class = i2c_class;
	chan->adapter.algo_data = &chan->algo;
	chan->adapter.dev.parent = &chan->par->pci_dev->dev;
	chan->algo.setsda = nvidia_gpio_setsda;
	chan->algo.setscl = nvidia_gpio_setscl;
	chan->algo.getsda = nvidia_gpio_getsda;
	chan->algo.getscl = nvidia_gpio_getscl;
	chan->algo.udelay = 40;
	chan->algo.timeout = msecs_to_jiffies(2);
	chan->algo.data = chan;

	i2c_set_adapdata(&chan->adapter, chan);

Annotation

Implementation Notes