From: Boris Brezillon <boris.brezillon@bootlin.com>
To: Chuanhua Han <chuanhua.han@nxp.com>
Cc: broonie@kernel.org, linux-spi@vger.kernel.org,
linux-kernel@vger.kernel.org, eha@deif.com
Subject: Re: [PATCH v2 1/4] spi: spi-mem: Add the spi_set_xfer_bpw function
Date: Sun, 30 Sep 2018 12:04:25 +0200 [thread overview]
Message-ID: <20180930120425.7715cb29@bbrezillon> (raw)
In-Reply-To: <20180930092535.24544-1-chuanhua.han@nxp.com>
Hi Chuanhua,
On Sun, 30 Sep 2018 17:25:32 +0800
Chuanhua Han <chuanhua.han@nxp.com> wrote:
> Before we add this spi_transfer to the spi_message chain table, we need
> bits_per_word_mask based on spi_control to set the bits_per_word of
> this spi_transfer.
Let's make it clearer: this is wrong. The spi-mem protocol is just
using bytes, not custom size words. Fix the fsl-dspi driver if needed,
but don't try to adjust xfer->bits_per_word in spi-mem.c, because this
is inappropriate.
Regards,
Boris
>
> Signed-off-by: Chuanhua Han <chuanhua.han@nxp.com>
> ---
> Changes in v2:
> -The original patch is divided into multiple patches(the original
> patch theme is "spi: spi-fsl-dspi: Fix support for XSPI transport
> mode"),one of which is segmented.
>
> drivers/spi/spi-mem.c | 39 +++++++++++++++++++++++++++++++++++++++
> 1 file changed, 39 insertions(+)
>
> diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
> index eb72dba71d83..717e711c0952 100644
> --- a/drivers/spi/spi-mem.c
> +++ b/drivers/spi/spi-mem.c
> @@ -175,6 +175,41 @@ bool spi_mem_supports_op(struct spi_mem *mem, const struct spi_mem_op *op)
> }
> EXPORT_SYMBOL_GPL(spi_mem_supports_op);
>
> +/**
> + * spi_set_xfer_bpw() - Set the bits_per_word for each transfer based on
> + * the bits_per_word_mask of the spi controller
> + * @ctrl: the spi controller
> + * @xfer: the spi transfer
> + *
> + * This function sets the bits_per_word for each transfer based on the spi
> + * controller's bits_per_word_mask to improve the efficiency of spi transport.
> + *
> + * Return: 0 in case of success, a negative error code otherwise.
> + */
> +int spi_set_xfer_bpw(struct spi_controller *ctlr, struct spi_transfer *xfer)
> +{
> + if (!ctlr || !xfer) {
> + dev_err(&ctlr->dev,
> + "Fail to set bits_per_word for spi transfer\n");
> + return -EINVAL;
> + }
> +
> + if (ctlr->bits_per_word_mask) {
> + if (!(xfer->len % 4)) {
> + if (ctlr->bits_per_word_mask & SPI_BPW_MASK(32))
> + xfer->bits_per_word = 32;
> + } else if (!(xfer->len % 2)) {
> + if (ctlr->bits_per_word_mask & SPI_BPW_MASK(16))
> + xfer->bits_per_word = 16;
> + } else {
> + xfer->bits_per_word = 8;
> + }
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(spi_set_xfer_bpw);
> +
> /**
> * spi_mem_exec_op() - Execute a memory operation
> * @mem: the SPI memory
> @@ -252,6 +287,7 @@ int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
> xfers[xferpos].tx_buf = tmpbuf;
> xfers[xferpos].len = sizeof(op->cmd.opcode);
> xfers[xferpos].tx_nbits = op->cmd.buswidth;
> + spi_set_xfer_bpw(ctlr, &xfers[xferpos]);
> spi_message_add_tail(&xfers[xferpos], &msg);
> xferpos++;
> totalxferlen++;
> @@ -266,6 +302,7 @@ int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
> xfers[xferpos].tx_buf = tmpbuf + 1;
> xfers[xferpos].len = op->addr.nbytes;
> xfers[xferpos].tx_nbits = op->addr.buswidth;
> + spi_set_xfer_bpw(ctlr, &xfers[xferpos]);
> spi_message_add_tail(&xfers[xferpos], &msg);
> xferpos++;
> totalxferlen += op->addr.nbytes;
> @@ -276,6 +313,7 @@ int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
> xfers[xferpos].tx_buf = tmpbuf + op->addr.nbytes + 1;
> xfers[xferpos].len = op->dummy.nbytes;
> xfers[xferpos].tx_nbits = op->dummy.buswidth;
> + spi_set_xfer_bpw(ctlr, &xfers[xferpos]);
> spi_message_add_tail(&xfers[xferpos], &msg);
> xferpos++;
> totalxferlen += op->dummy.nbytes;
> @@ -291,6 +329,7 @@ int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
> }
>
> xfers[xferpos].len = op->data.nbytes;
> + spi_set_xfer_bpw(ctlr, &xfers[xferpos]);
> spi_message_add_tail(&xfers[xferpos], &msg);
> xferpos++;
> totalxferlen += op->data.nbytes;
next prev parent reply other threads:[~2018-09-30 10:04 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-30 9:25 [PATCH v2 1/4] spi: spi-mem: Add the spi_set_xfer_bpw function Chuanhua Han
2018-09-30 9:25 ` [PATCH v2 2/4] spi: spi-fsl-dspi: Fix delete the processing of undefined bitmask for rxdata Chuanhua Han
2018-09-30 10:06 ` Boris Brezillon
2018-09-30 10:10 ` Chuanhua Han
2018-09-30 10:17 ` Boris Brezillon
2018-09-30 10:37 ` Chuanhua Han
2018-09-30 10:37 ` Esben Haabendal
2018-09-30 10:41 ` Boris Brezillon
2018-09-30 10:29 ` Esben Haabendal
2018-09-30 9:25 ` [PATCH v2 3/4] spi: spi-fsl-dspi: Fix cmd_fifo is written before tx_fifo Chuanhua Han
2018-09-30 10:30 ` Esben Haabendal
2018-09-30 9:25 ` [PATCH v2 4/4] spi: spi-fsl-dspi: Fix adjust the byte order when sending and receiving data Chuanhua Han
2018-09-30 10:27 ` Esben Haabendal
2018-09-30 10:04 ` Boris Brezillon [this message]
2018-09-30 10:17 ` [PATCH v2 1/4] spi: spi-mem: Add the spi_set_xfer_bpw function Esben Haabendal
2018-09-30 10:40 ` Chuanhua Han
2018-09-30 10:18 ` Chuanhua Han
2018-09-30 10:40 ` Boris Brezillon
2018-09-30 10:48 ` Chuanhua Han
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180930120425.7715cb29@bbrezillon \
--to=boris.brezillon@bootlin.com \
--cc=broonie@kernel.org \
--cc=chuanhua.han@nxp.com \
--cc=eha@deif.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-spi@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).