LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
To: "Mark Brown" <broonie@kernel.org>,
	"Michal Simek" <michal.simek@xilinx.com>,
	"Sören Brinkmann" <soren.brinkmann@xilinx.com>,
	linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Cc: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Subject: [PATCH 08/18] spi/xilinx: Support cores with no interrupt
Date: Fri, 23 Jan 2015 17:08:40 +0100	[thread overview]
Message-ID: <1422029330-10971-9-git-send-email-ricardo.ribalda@gmail.com> (raw)
In-Reply-To: <1422029330-10971-1-git-send-email-ricardo.ribalda@gmail.com>

The core can run in polling mode. In fact, the performance of the core
is similar (or even better), due to the fact most of the spi
transactions are just a couple of bytes and there is one irq per
transactions.

When an mtd device is connected via spi, reading 8MB of data produces
more than 80K interrupts (with irq disabling, context swith....)

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
---
 drivers/spi/spi-xilinx.c | 33 +++++++++++++++++++--------------
 1 file changed, 19 insertions(+), 14 deletions(-)

diff --git a/drivers/spi/spi-xilinx.c b/drivers/spi/spi-xilinx.c
index 3f8450d..8a28cab 100644
--- a/drivers/spi/spi-xilinx.c
+++ b/drivers/spi/spi-xilinx.c
@@ -173,8 +173,11 @@ static void xspi_init_hw(struct xilinx_spi *xspi)
 	xspi->write_fn(XSPI_INTR_TX_EMPTY,
 			regs_base + XIPIF_V123B_IIER_OFFSET);
 	/* Enable the global IPIF interrupt */
-	xspi->write_fn(XIPIF_V123B_GINTR_ENABLE,
-		regs_base + XIPIF_V123B_DGIER_OFFSET);
+	if (xspi->irq >= 0)
+		xspi->write_fn(XIPIF_V123B_GINTR_ENABLE,
+			regs_base + XIPIF_V123B_DGIER_OFFSET);
+	else
+		xspi->write_fn(0, regs_base + XIPIF_V123B_DGIER_OFFSET);
 	/* Deselect the slave on the SPI bus */
 	xspi->write_fn(0xffff, regs_base + XSPI_SSR_OFFSET);
 	/* Disable the transmitter, enable Manual Slave Select Assertion,
@@ -264,7 +267,12 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
 							~XSPI_CR_TRANS_INHIBIT;
 		xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET);
 
-		wait_for_completion(&xspi->done);
+		if (xspi->irq >= 0)
+			wait_for_completion(&xspi->done);
+		else
+			while (!(xspi->read_fn(xspi->regs + XSPI_SR_OFFSET) &
+						XSPI_SR_TX_EMPTY_MASK))
+				;
 
 		/* A transmit has just completed. Process received data and
 		 * check for more data to transmit. Always inhibit the
@@ -412,20 +420,17 @@ static int xilinx_spi_probe(struct platform_device *pdev)
 
 	xspi->buffer_size = xilinx_spi_find_buffer_size(xspi);
 
-	/* SPI controller initializations */
-	xspi_init_hw(xspi);
-
 	xspi->irq = platform_get_irq(pdev, 0);
-	if (xspi->irq < 0) {
-		ret = xspi->irq;
-		goto put_master;
+	if (xspi->irq >= 0) {
+		/* Register for SPI Interrupt */
+		ret = devm_request_irq(&pdev->dev, xspi->irq, xilinx_spi_irq, 0,
+				dev_name(&pdev->dev), xspi);
+		if (ret)
+			goto put_master;
 	}
 
-	/* Register for SPI Interrupt */
-	ret = devm_request_irq(&pdev->dev, xspi->irq, xilinx_spi_irq, 0,
-			       dev_name(&pdev->dev), xspi);
-	if (ret)
-		goto put_master;
+	/* SPI controller initializations */
+	xspi_init_hw(xspi);
 
 	ret = spi_bitbang_start(&xspi->bitbang);
 	if (ret) {
-- 
2.1.4


  parent reply	other threads:[~2015-01-23 16:13 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-23 16:08 [PATCH 00/18] spi/xilinx: Speed-up Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 01/18] spi/xilinx: Support for spi mode LSB_FIRST Ricardo Ribalda Delgado
2015-01-26 19:23   ` Mark Brown
2015-01-23 16:08 ` [PATCH 02/18] spi/xilinx: Support for spi mode LOOP Ricardo Ribalda Delgado
2015-01-26 19:23   ` Mark Brown
2015-01-23 16:08 ` [PATCH 03/18] spi/xilinx: Simplify data read from the Rx FIFO Ricardo Ribalda Delgado
2015-01-27 17:25   ` Mark Brown
2015-01-23 16:08 ` [PATCH 04/18] spi-xilinx: Simplify spi_fill_tx_fifo Ricardo Ribalda Delgado
2015-01-26 23:54   ` Mark Brown
2015-01-23 16:08 ` [PATCH 05/18] spi/xilinx: Leave the IRQ always enabled Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 06/18] spi/xilinx: Code cleanup Ricardo Ribalda Delgado
2015-01-27  0:05   ` Mark Brown
2015-01-23 16:08 ` [PATCH 07/18] spi/xilinx: Use cached value of register Ricardo Ribalda Delgado
2015-01-23 16:08 ` Ricardo Ribalda Delgado [this message]
2015-01-27  0:04   ` [PATCH 08/18] spi/xilinx: Support cores with no interrupt Mark Brown
2015-01-27 19:05     ` Ricardo Ribalda Delgado
2015-01-27 19:49       ` Mark Brown
2015-01-27 19:56         ` Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 09/18] spi/xilinx: Do not inhibit transmission in polling mode Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 10/18] spi/xilinx: Support for spi mode CS_HIGH Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 11/18] spi/xilinx: Remove rx_fn and tx_fn pointer Ricardo Ribalda Delgado
2015-01-27  0:09   ` Mark Brown
2015-01-27 10:00     ` Ricardo Ribalda Delgado
2015-01-27 15:42       ` Joe Perches
2015-01-27 19:07         ` Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 12/18] spi/xilinx: Make spi_tx and spi_rx simmetric Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 13/18] spi/xilinx: Convert remainding_bytes in remaining words Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 14/18] spi/xilinx: Convert bits_per_word in bytes_per_word Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 15/18] spi/xilinx: Remove iowrite/ioread wrappers Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 16/18] spi/xilinx: Reset core before buffer_size detection Ricardo Ribalda Delgado
2015-01-27  0:11   ` Mark Brown
2015-01-23 16:08 ` [PATCH 17/18] spi/xilinx: Remove remaining_words driver data variable Ricardo Ribalda Delgado
2015-01-23 16:08 ` [PATCH 18/18] spi/xilinx: Check number of slaves range Ricardo Ribalda Delgado
2015-01-27  0:14 ` [PATCH 00/18] spi/xilinx: Speed-up Mark Brown
2015-01-27 10:17   ` Ricardo Ribalda Delgado
2015-01-27 11:59     ` Mark Brown

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=1422029330-10971-9-git-send-email-ricardo.ribalda@gmail.com \
    --to=ricardo.ribalda@gmail.com \
    --cc=broonie@kernel.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-spi@vger.kernel.org \
    --cc=michal.simek@xilinx.com \
    --cc=soren.brinkmann@xilinx.com \
    --subject='Re: [PATCH 08/18] spi/xilinx: Support cores with no interrupt' \
    /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

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).