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Commit d3b542fc authored by Shobhit Kumar's avatar Shobhit Kumar Committed by Daniel Vetter
Browse files

drm/i915: Add parsing support for new MIPI blocks in VBT 



The parser extracts the config block(#52) and sequence(#53) data
and store in private data structures.

v2: Address review comments by Jani
    - adjust code for the structure changes for bdb_mipi_config
    - add boundry and buffer overflow checks as suggested
    - use kmemdup instead of kmalloc and memcpy

v3: More strict check while parsing VBT
    - Ensure that at anytime we do not go beyond sequence block
      while parsing
    - On unknown element fail the whole parsing

v4: Style changes and spell check mostly as suggested by Jani

Signed-off-by: default avatarShobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: default avatarJani Nikula <jani.nikula@intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent 773875bf

drivers/gpu/drm/i915/i915_drv.h

+6 −0
Original line number Diff line number Diff line
@@ -1169,6 +1169,12 @@ struct intel_vbt_data { 
	/* MIPI DSI */

	struct {

		u16 panel_id;

		struct mipi_config *config;

		struct mipi_pps_data *pps;

		u8 seq_version;

		u32 size;

		u8 *data;

		u8 *sequence[MIPI_SEQ_MAX];

	} dsi;



	int crt_ddc_pin;

drivers/gpu/drm/i915/intel_bios.c

+199 −5
Original line number Diff line number Diff line
@@ -626,19 +626,213 @@ parse_edp(struct drm_i915_private *dev_priv, struct bdb_header *bdb) 
	}

}



static u8 *goto_next_sequence(u8 *data, int *size)

{

	u16 len;

	int tmp = *size;



	if (--tmp < 0)

		return NULL;



	/* goto first element */

	data++;

	while (1) {

		switch (*data) {

		case MIPI_SEQ_ELEM_SEND_PKT:

			/*

			 * skip by this element payload size

			 * skip elem id, command flag and data type

			 */

			if ((tmp = tmp - 5) < 0)

				return NULL;



			data += 3;

			len = *((u16 *)data);



			if ((tmp = tmp - len) < 0)

				return NULL;



			/* skip by len */

			data = data + 2 + len;

			break;

		case MIPI_SEQ_ELEM_DELAY:

			/* skip by elem id, and delay is 4 bytes */

			if ((tmp = tmp - 5) < 0)

				return NULL;



			data += 5;

			break;

		case MIPI_SEQ_ELEM_GPIO:

			if ((tmp = tmp - 3) < 0)

				return NULL;



			data += 3;

			break;

		default:

			DRM_ERROR("Unknown element\n");

			return NULL;

		}



		/* end of sequence ? */

		if (*data == 0)

			break;

	}



	/* goto next sequence or end of block byte */

	if (--tmp < 0)

		return NULL;



	data++;



	/* update amount of data left for the sequence block to be parsed */

	*size = tmp;

	return data;

}



static void

parse_mipi(struct drm_i915_private *dev_priv, struct bdb_header *bdb)

{

	struct bdb_mipi *mipi;

	struct bdb_mipi_config *start;

	struct bdb_mipi_sequence *sequence;

	struct mipi_config *config;

	struct mipi_pps_data *pps;

	u8 *data, *seq_data;

	int i, panel_id, seq_size;

	u16 block_size;



	/* Initialize this to undefined indicating no generic MIPI support */

	dev_priv->vbt.dsi.panel_id = MIPI_DSI_UNDEFINED_PANEL_ID;



	/* Block #40 is already parsed and panel_fixed_mode is

	 * stored in dev_priv->lfp_lvds_vbt_mode

	 * resuse this when needed

	 */



	/* Parse #52 for panel index used from panel_type already

	 * parsed

	 */

	start = find_section(bdb, BDB_MIPI_CONFIG);

	if (!start) {

		DRM_DEBUG_KMS("No MIPI config BDB found");

		return;

	}



	DRM_DEBUG_DRIVER("Found MIPI Config block, panel index = %d\n",

								panel_type);



	/*

	 * get hold of the correct configuration block and pps data as per

	 * the panel_type as index

	 */

	config = &start->config[panel_type];

	pps = &start->pps[panel_type];



	/* store as of now full data. Trim when we realise all is not needed */

	dev_priv->vbt.dsi.config = kmemdup(config, sizeof(struct mipi_config), GFP_KERNEL);

	if (!dev_priv->vbt.dsi.config)

		return;



	mipi = find_section(bdb, BDB_MIPI_CONFIG);

	if (!mipi) {

		DRM_DEBUG_KMS("No MIPI BDB found");

	dev_priv->vbt.dsi.pps = kmemdup(pps, sizeof(struct mipi_pps_data), GFP_KERNEL);

	if (!dev_priv->vbt.dsi.pps) {

		kfree(dev_priv->vbt.dsi.config);

		return;

	}



	/* XXX: add more info */

	/* We have mandatory mipi config blocks. Initialize as generic panel */

	dev_priv->vbt.dsi.panel_id = MIPI_DSI_GENERIC_PANEL_ID;



	/* Check if we have sequence block as well */

	sequence = find_section(bdb, BDB_MIPI_SEQUENCE);

	if (!sequence) {

		DRM_DEBUG_KMS("No MIPI Sequence found, parsing complete\n");

		return;

	}



	DRM_DEBUG_DRIVER("Found MIPI sequence block\n");



	block_size = get_blocksize(sequence);



	/*

	 * parse the sequence block for individual sequences

	 */

	dev_priv->vbt.dsi.seq_version = sequence->version;



	seq_data = &sequence->data[0];



	/*

	 * sequence block is variable length and hence we need to parse and

	 * get the sequence data for specific panel id

	 */

	for (i = 0; i < MAX_MIPI_CONFIGURATIONS; i++) {

		panel_id = *seq_data;

		seq_size = *((u16 *) (seq_data + 1));

		if (panel_id == panel_type)

			break;



		/* skip the sequence including seq header of 3 bytes */

		seq_data = seq_data + 3 + seq_size;

		if ((seq_data - &sequence->data[0]) > block_size) {

			DRM_ERROR("Sequence start is beyond sequence block size, corrupted sequence block\n");

			return;

		}

	}



	if (i == MAX_MIPI_CONFIGURATIONS) {

		DRM_ERROR("Sequence block detected but no valid configuration\n");

		return;

	}



	/* check if found sequence is completely within the sequence block

	 * just being paranoid */

	if (seq_size > block_size) {

		DRM_ERROR("Corrupted sequence/size, bailing out\n");

		return;

	}



	/* skip the panel id(1 byte) and seq size(2 bytes) */

	dev_priv->vbt.dsi.data = kmemdup(seq_data + 3, seq_size, GFP_KERNEL);

	if (!dev_priv->vbt.dsi.data)

		return;



	/*

	 * loop into the sequence data and split into multiple sequneces

	 * There are only 5 types of sequences as of now

	 */

	data = dev_priv->vbt.dsi.data;

	dev_priv->vbt.dsi.size = seq_size;



	/* two consecutive 0x00 indicate end of all sequences */

	while (1) {

		int seq_id = *data;

		if (MIPI_SEQ_MAX > seq_id && seq_id > MIPI_SEQ_UNDEFINED) {

			dev_priv->vbt.dsi.sequence[seq_id] = data;

			DRM_DEBUG_DRIVER("Found mipi sequence - %d\n", seq_id);

		} else {

			DRM_ERROR("undefined sequence\n");

			goto err;

		}



		/* partial parsing to skip elements */

		data = goto_next_sequence(data, &seq_size);



		if (data == NULL) {

			DRM_ERROR("Sequence elements going beyond block itself. Sequence block parsing failed\n");

			goto err;

		}



		if (*data == 0)

			break; /* end of sequence reached */

	}



	DRM_DEBUG_DRIVER("MIPI related vbt parsing complete\n");

	return;

err:

	kfree(dev_priv->vbt.dsi.data);

	dev_priv->vbt.dsi.data = NULL;



	/* error during parsing so set all pointers to null

	 * because of partial parsing */

	memset(dev_priv->vbt.dsi.sequence, 0, MIPI_SEQ_MAX);

}



static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port,

drivers/gpu/drm/i915/intel_bios.h

+31 −0
Original line number Diff line number Diff line
@@ -896,4 +896,35 @@ struct bdb_mipi_sequence { 
	u8 data[0];

};



/* MIPI Sequnece Block definitions */

enum mipi_seq {

	MIPI_SEQ_UNDEFINED = 0,

	MIPI_SEQ_ASSERT_RESET,

	MIPI_SEQ_INIT_OTP,

	MIPI_SEQ_DISPLAY_ON,

	MIPI_SEQ_DISPLAY_OFF,

	MIPI_SEQ_DEASSERT_RESET,

	MIPI_SEQ_MAX

};



enum mipi_seq_element {

	MIPI_SEQ_ELEM_UNDEFINED = 0,

	MIPI_SEQ_ELEM_SEND_PKT,

	MIPI_SEQ_ELEM_DELAY,

	MIPI_SEQ_ELEM_GPIO,

	MIPI_SEQ_ELEM_STATUS,

	MIPI_SEQ_ELEM_MAX

};



enum mipi_gpio_pin_index {

	MIPI_GPIO_UNDEFINED = 0,

	MIPI_GPIO_PANEL_ENABLE,

	MIPI_GPIO_BL_ENABLE,

	MIPI_GPIO_PWM_ENABLE,

	MIPI_GPIO_RESET_N,

	MIPI_GPIO_PWR_DOWN_R,

	MIPI_GPIO_STDBY_RST_N,

	MIPI_GPIO_MAX

};



#endif /* _I830_BIOS_H_ */