From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sourav Poddar Subject: [RFC/PATCH 2/2] driver: spi: Add quad spi read support Date: Fri, 26 Jul 2013 22:45:22 +0530 Message-ID: <1374858922-14637-3-git-send-email-sourav.poddar@ti.com> References: <1374858922-14637-1-git-send-email-sourav.poddar@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, rnayak-l0cyMroinI0@public.gmane.org, Sourav, Poddar , balbi-l0cyMroinI0@public.gmane.org To: , , Return-path: In-Reply-To: <1374858922-14637-1-git-send-email-sourav.poddar-l0cyMroinI0@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-spi.vger.kernel.org Since, qspi controller uses quad read. Configuring the command register, if the transfer of data needs dual or quad lines. This patch has been done on top of the following patch[1], which is the basic idea of adding dual/quad support in spi framework. $subject patch will undergo changes with the ongoing discussion in the community. This patch is posted to demonstrate how patch 1 of the series will support quad read. [1]: http://comments.gmane.org/gmane.linux.kernel.spi.devel/14047 Signed-off-by: Sourav Poddar --- drivers/spi/spi-ti-qspi.c | 16 ++++++++++++++-- 1 files changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/spi/spi-ti-qspi.c b/drivers/spi/spi-ti-qspi.c index 7c848c8..679c813 100644 --- a/drivers/spi/spi-ti-qspi.c +++ b/drivers/spi/spi-ti-qspi.c @@ -86,6 +86,7 @@ struct ti_qspi { #define QSPI_3_PIN (1 << 18) #define QSPI_RD_SNGL (1 << 16) #define QSPI_WR_SNGL (2 << 16) +#define QSPI_RD_DUAL (3 << 16) #define QSPI_RD_QUAD (7 << 16) #define QSPI_INVAL (4 << 16) #define QSPI_WC_CMD_INT_EN (1 << 14) @@ -290,6 +291,7 @@ static void qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t) { u8 *rxbuf; int wlen, count; + unsigned cmd = qspi->cmd; count = t->len; rxbuf = t->rx_buf; @@ -299,8 +301,18 @@ static void qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t) dev_dbg(qspi->dev, "rx cmd %08x dc %08x\n", qspi->cmd | QSPI_RD_SNGL, qspi->dc); ti_qspi_write(qspi, qspi->dc, QSPI_SPI_DC_REG); - ti_qspi_write(qspi, qspi->cmd | QSPI_RD_SNGL, - QSPI_SPI_CMD_REG); + switch (t->bitwidth) { + case SPI_BITWIDTH_QUAD: + cmd |= QSPI_RD_QUAD; + break; + case SPI_BITWIDTH_DUAL: + cmd |= QSPI_RD_DUAL; + break; + case SPI_BITWIDTH_SINGLE: + default: + cmd |= QSPI_RD_SNGL; + } + ti_qspi_writel(qspi, cmd, QSPI_SPI_CMD_REG); ti_qspi_write(qspi, QSPI_WC_INT_EN, QSPI_INTR_ENABLE_SET_REG); wait_for_completion(&qspi->transfer_complete); ti_qspi_read_data(qspi, QSPI_SPI_DATA_REG, wlen, &rxbuf); -- 1.7.1 ------------------------------------------------------------------------------ See everything from the browser to the database with AppDynamics Get end-to-end visibility with application monitoring from AppDynamics Isolate bottlenecks and diagnose root cause in seconds. Start your free trial of AppDynamics Pro today! http://pubads.g.doubleclick.net/gampad/clk?id=48808831&iu=/4140/ostg.clktrk