drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c
Extension
.c
Size
23480 bytes
Lines
765
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

while (buf_len > 0) {
			cur_size = MIN(buf_len, HDCP_MAX_AUX_TRANSACTION_SIZE);
			success = hdcp->config.ddc.funcs.read_dpcd(hdcp->config.ddc.handle,
					hdcp_dpcd_addrs[msg_id] + data_offset,
					buf + data_offset,
					cur_size);

			if (!success)
				break;

			buf_len -= cur_size;
			data_offset += cur_size;
		}
	} else {
		int num_i2c_offsets = ARRAY_SIZE(hdcp_i2c_offsets);
		if (msg_id >= num_i2c_offsets)
			return MOD_HDCP_STATUS_DDC_FAILURE;

		success = hdcp->config.ddc.funcs.read_i2c(
				hdcp->config.ddc.handle,
				HDCP_I2C_ADDR,
				hdcp_i2c_offsets[msg_id],
				buf,
				(uint32_t)buf_len);
	}

	return success ? MOD_HDCP_STATUS_SUCCESS : MOD_HDCP_STATUS_DDC_FAILURE;
}

static enum mod_hdcp_status read_repeatedly(struct mod_hdcp *hdcp,
		enum mod_hdcp_ddc_message_id msg_id,
		uint8_t *buf,
		uint32_t buf_len,
		uint8_t read_size)
{
	enum mod_hdcp_status status = MOD_HDCP_STATUS_DDC_FAILURE;
	uint32_t cur_size = 0;
	uint32_t data_offset = 0;

	while (buf_len > 0) {
		cur_size = MIN(buf_len, read_size);
		status = read(hdcp, msg_id, buf + data_offset, cur_size);

		if (status != MOD_HDCP_STATUS_SUCCESS)
			break;

		buf_len -= cur_size;
		data_offset += cur_size;
	}

	return status;
}

static enum mod_hdcp_status write(struct mod_hdcp *hdcp,
		enum mod_hdcp_ddc_message_id msg_id,
		uint8_t *buf,
		uint32_t buf_len)
{
	bool success = true;
	uint32_t cur_size = 0;
	uint32_t data_offset = 0;

	if (msg_id == MOD_HDCP_MESSAGE_ID_INVALID ||
		msg_id >= MOD_HDCP_MESSAGE_ID_MAX)
		return MOD_HDCP_STATUS_DDC_FAILURE;

	if (is_dp_hdcp(hdcp)) {
		int num_dpcd_addrs = ARRAY_SIZE(hdcp_dpcd_addrs);
		if (msg_id >= num_dpcd_addrs)
			return MOD_HDCP_STATUS_DDC_FAILURE;

		while (buf_len > 0) {
			cur_size = MIN(buf_len, HDCP_MAX_AUX_TRANSACTION_SIZE);
			success = hdcp->config.ddc.funcs.write_dpcd(
					hdcp->config.ddc.handle,
					hdcp_dpcd_addrs[msg_id] + data_offset,
					buf + data_offset,
					cur_size);

			if (!success)
				break;

			buf_len -= cur_size;
			data_offset += cur_size;
		}
	} else {
		int num_i2c_offsets = ARRAY_SIZE(hdcp_i2c_offsets);
		if (msg_id >= num_i2c_offsets)
			return MOD_HDCP_STATUS_DDC_FAILURE;

Annotation

Implementation Notes