drivers/gpu/drm/i915/display/dvo_ch7xxx.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/i915/display/dvo_ch7xxx.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/i915/display/dvo_ch7xxx.c
Extension
.c
Size
8876 bytes
Lines
388
Domain
Driver Families
Bucket
drivers/gpu
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

struct ch7xxx_priv {
	bool quiet;
};

static char *ch7xxx_get_id(u8 vid)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(ch7xxx_ids); i++) {
		if (ch7xxx_ids[i].vid == vid)
			return ch7xxx_ids[i].name;
	}

	return NULL;
}

static char *ch7xxx_get_did(u8 did)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(ch7xxx_dids); i++) {
		if (ch7xxx_dids[i].did == did)
			return ch7xxx_dids[i].name;
	}

	return NULL;
}

/** Reads an 8 bit register */
static bool ch7xxx_readb(struct intel_dvo_device *dvo, int addr, u8 *ch)
{
	struct ch7xxx_priv *ch7xxx = dvo->dev_priv;
	struct i2c_adapter *adapter = dvo->i2c_bus;
	u8 out_buf[2];
	u8 in_buf[2];

	struct i2c_msg msgs[] = {
		{
			.addr = dvo->target_addr,
			.flags = 0,
			.len = 1,
			.buf = out_buf,
		},
		{
			.addr = dvo->target_addr,
			.flags = I2C_M_RD,
			.len = 1,
			.buf = in_buf,
		}
	};

	out_buf[0] = addr;
	out_buf[1] = 0;

	if (i2c_transfer(adapter, msgs, 2) == 2) {
		*ch = in_buf[0];
		return true;
	}

	if (!ch7xxx->quiet) {
		DRM_DEBUG_KMS("Unable to read register 0x%02x from %s:%02x.\n",
			  addr, adapter->name, dvo->target_addr);
	}
	return false;
}

/** Writes an 8 bit register */
static bool ch7xxx_writeb(struct intel_dvo_device *dvo, int addr, u8 ch)
{
	struct ch7xxx_priv *ch7xxx = dvo->dev_priv;
	struct i2c_adapter *adapter = dvo->i2c_bus;
	u8 out_buf[2];
	struct i2c_msg msg = {
		.addr = dvo->target_addr,
		.flags = 0,
		.len = 2,
		.buf = out_buf,
	};

	out_buf[0] = addr;
	out_buf[1] = ch;

	if (i2c_transfer(adapter, &msg, 1) == 1)
		return true;

	if (!ch7xxx->quiet) {
		DRM_DEBUG_KMS("Unable to write register 0x%02x to %s:%d.\n",
			  addr, adapter->name, dvo->target_addr);
	}

Annotation

Implementation Notes