[Intel-gfx] [PATCH v3] drm/i915: Add parsing support for new MIPI blocks in VBT

Daniel Vetter daniel at ffwll.ch
Mon Apr 14 09:02:51 CEST 2014


On Mon, Apr 14, 2014 at 11:00:34AM +0530, Shobhit Kumar wrote:
> 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: Shobhit Kumar <shobhit.kumar at intel.com>
> Reviewed-by: Jani Nikula <jani.nikula at intel.com>

I didn't spot Jani's r-b tag in earlier mails, was that done off-list?
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_drv.h   |   6 ++
>  drivers/gpu/drm/i915/intel_bios.c | 204 +++++++++++++++++++++++++++++++++++++-
>  drivers/gpu/drm/i915/intel_bios.h |  31 ++++++
>  3 files changed, 236 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 85e362f..1b763aa 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1170,6 +1170,12 @@ 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;
> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
> index 862ca04..917f5bb 100644
> --- a/drivers/gpu/drm/i915/intel_bios.c
> +++ b/drivers/gpu/drm/i915/intel_bios.c
> @@ -636,19 +636,213 @@ 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
> +	 */
>  
> -	mipi = find_section(bdb, BDB_MIPI_CONFIG);
> -	if (!mipi) {
> -		DRM_DEBUG_KMS("No MIPI BDB found");
> +	/* 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;
>  	}
>  
> -	/* XXX: add more info */
> +	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;
> +
> +	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;
> +	}
> +
> +	/* 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,
> diff --git a/drivers/gpu/drm/i915/intel_bios.h b/drivers/gpu/drm/i915/intel_bios.h
> index 036a799..6009deb 100644
> --- a/drivers/gpu/drm/i915/intel_bios.h
> +++ b/drivers/gpu/drm/i915/intel_bios.h
> @@ -899,4 +899,35 @@ 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_ */
> -- 
> 1.8.3.2
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch



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