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Commit 5f643c9b authored by Ankit Gupta's avatar Ankit Gupta
Browse files

i2c-msm-v2: remove stop tag after every read 



Multiple buffers are used for the xfers which are
larger than 256 bytes. This patch allows such buffers
to add a repeated start tag for the subsequent read buffers
in a read message instead of adding a stop tag. Only last
buffer in a message uses a STOP tag.

Change-Id: I462c1ee88f247586b984ff6d1c9c799538bc2e90
Signed-off-by: default avatarAnkit Gupta <ankgupta@codeaurora.org>
parent dbd98701

drivers/i2c/busses/i2c-msm-v2.c

+4 −10
Original line number Diff line number Diff line
@@ -260,13 +260,13 @@ static u8 *i2c_msm_buf_to_ptr(struct i2c_msm_xfer_buf *buf) 
 */

static const struct i2c_msm_tag tag_lookup_table[2][2][2] = {

	{{{QUP_TAG2_DATA_WRITE                                   , 2},

	   {QUP_TAG2_DATA_READ_N_STOP                             , 2} },

	   {QUP_TAG2_DATA_READ                                   , 2} },

	/* last buffer */

	  {{QUP_TAG2_DATA_WRITE_N_STOP                            , 2},

	   {QUP_TAG2_DATA_READ_N_STOP                             , 2} } } ,

	/* new addr */

	 {{{QUP_TAG2_START | (QUP_TAG2_DATA_WRITE           << 16), 4},

	   {QUP_TAG2_START | (QUP_TAG2_DATA_READ_N_STOP     << 16), 4} },

	   {QUP_TAG2_START | (QUP_TAG2_DATA_READ            << 16), 4} },

	/* last buffer + new addr */

	  {{QUP_TAG2_START | (QUP_TAG2_DATA_WRITE_N_STOP    << 16), 4},

	   {QUP_TAG2_START | (QUP_TAG2_DATA_READ_N_STOP     << 16), 4} } },
@@ -2631,14 +2631,8 @@ static bool i2c_msm_xfer_next_buf(struct i2c_msm_ctrl *ctrl) 
		cur_buf->len    = min_t(size_t, bc_rem, ctrl->ver.max_buf_size);

		cur_buf->prcsed_bc += cur_buf->len;



		/*

		 * workaround! due to HW issue, a stop is issued after every

		 * read. Once we here we know that this is not the first

		 * buffer of the current message. And if the current message

		 * is Rx then the previous buffers was Rx as well, we already

		 * issued a stop, and we need to issue a start.

		 */

		i2c_msm_xfer_create_cur_tag(ctrl, cur_buf->is_rx);

		/* No Start is required if it is not a first buffer in msg */

		i2c_msm_xfer_create_cur_tag(ctrl, false);

	} else {

		/* first buffer in a new message */

		if (cur_buf->is_init) {