drivers/gpu/drm/gma500/cdv_intel_dp.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/gma500/cdv_intel_dp.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/gma500/cdv_intel_dp.c
Extension
.c
Size
56727 bytes
Lines
2095
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 i2c_algo_dp_aux_data {
	bool running;
	u16 address;
	int (*aux_ch) (struct i2c_adapter *adapter,
		       int mode, uint8_t write_byte,
		       uint8_t *read_byte);
};

/* Run a single AUX_CH I2C transaction, writing/reading data as necessary */
static int
i2c_algo_dp_aux_transaction(struct i2c_adapter *adapter, int mode,
			    uint8_t write_byte, uint8_t *read_byte)
{
	struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;
	int ret;

	ret = (*algo_data->aux_ch)(adapter, mode,
				   write_byte, read_byte);
	return ret;
}

/*
 * I2C over AUX CH
 */

/*
 * Send the address. If the I2C link is running, this 'restarts'
 * the connection with the new address, this is used for doing
 * a write followed by a read (as needed for DDC)
 */
static int
i2c_algo_dp_aux_address(struct i2c_adapter *adapter, u16 address, bool reading)
{
	struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;
	int mode = MODE_I2C_START;

	if (reading)
		mode |= MODE_I2C_READ;
	else
		mode |= MODE_I2C_WRITE;
	algo_data->address = address;
	algo_data->running = true;
	return i2c_algo_dp_aux_transaction(adapter, mode, 0, NULL);
}

/*
 * Stop the I2C transaction. This closes out the link, sending
 * a bare address packet with the MOT bit turned off
 */
static void
i2c_algo_dp_aux_stop(struct i2c_adapter *adapter, bool reading)
{
	struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;
	int mode = MODE_I2C_STOP;

	if (reading)
		mode |= MODE_I2C_READ;
	else
		mode |= MODE_I2C_WRITE;
	if (algo_data->running) {
		(void) i2c_algo_dp_aux_transaction(adapter, mode, 0, NULL);
		algo_data->running = false;
	}
}

/*
 * Write a single byte to the current I2C address, the
 * I2C link must be running or this returns -EIO
 */
static int
i2c_algo_dp_aux_put_byte(struct i2c_adapter *adapter, u8 byte)
{
	struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;

	if (!algo_data->running)
		return -EIO;

	return i2c_algo_dp_aux_transaction(adapter, MODE_I2C_WRITE, byte, NULL);
}

/*
 * Read a single byte from the current I2C address, the
 * I2C link must be running or this returns -EIO
 */
static int
i2c_algo_dp_aux_get_byte(struct i2c_adapter *adapter, u8 *byte_ret)
{
	struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;

	if (!algo_data->running)

Annotation

Implementation Notes