From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Gamari Subject: [PATCH] mcspi: Add support for GPIO chip select lines Date: Tue, 21 Dec 2010 12:56:35 -0500 Message-ID: <1292954195-20204-2-git-send-email-bgamari.foss@gmail.com> References: <1b68c6791001272033q60dd31dbif4de285cd9bac83d@mail.gmail.com> Return-path: Received: from mail-vw0-f46.google.com ([209.85.212.46]:48541 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751736Ab0LUR4p (ORCPT ); Tue, 21 Dec 2010 12:56:45 -0500 Received: by vws16 with SMTP id 16so1814897vws.19 for ; Tue, 21 Dec 2010 09:56:45 -0800 (PST) In-Reply-To: <1b68c6791001272033q60dd31dbif4de285cd9bac83d@mail.gmail.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: beagleboard , linux-omap , David Brownell , Eric Miao , Michael Cc: Ben Gamari This mechanism is in large part stolen from the s3c64xx-spi module. To use this functionality, one simply must define a set_level function to set the CS state and a omap2_mcspi_csinfo struct for each chip select in the board file. Each spi_board_info.controller_data should then be set to point to the appropriate csinfo struct. This will cause the driver to call the csinfo->set_level function instead of toggling the McSPI chip select lines. Signed-off-by: Ben Gamari --- arch/arm/plat-omap/include/plat/mcspi.h | 14 ++++++++++++++ drivers/spi/omap2_mcspi.c | 14 +++++++++----- 2 files changed, 23 insertions(+), 5 deletions(-) diff --git a/arch/arm/plat-omap/include/plat/mcspi.h b/arch/arm/plat-omap/include/plat/mcspi.h index 1254e49..ab84b8d 100644 --- a/arch/arm/plat-omap/include/plat/mcspi.h +++ b/arch/arm/plat-omap/include/plat/mcspi.h @@ -1,6 +1,20 @@ #ifndef _OMAP2_MCSPI_H #define _OMAP2_MCSPI_H +/** + * struct omap2_mcspi_csinfo - Chip Select description + * @line: Custom 'identity' of the CS line + * @set_level: Function to set the state of a given CS line + * + * This is to allow use of GPIO lines as CS lines. Allocate and initialize one + * in the machine init code and make spi_board_info.controller_data point to + * it. + */ +struct omap2_mcspi_csinfo { + unsigned line; + void (*set_level)(unsigned line_id, int lvl); +}; + struct omap2_mcspi_platform_config { unsigned short num_cs; }; diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c index 2a651e6..92ccbd6 100644 --- a/drivers/spi/omap2_mcspi.c +++ b/drivers/spi/omap2_mcspi.c @@ -35,6 +35,7 @@ #include #include +#include #include #include @@ -235,11 +236,14 @@ static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable) static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active) { - u32 l; - - l = mcspi_cached_chconf0(spi); - MOD_REG_BIT(l, OMAP2_MCSPI_CHCONF_FORCE, cs_active); - mcspi_write_chconf0(spi, l); + if (spi->controller_data) { + struct omap2_mcspi_csinfo *csinfo = spi->controller_data; + (*csinfo->set_level)(csinfo->line, cs_active); + } else { + u32 l = mcspi_cached_chconf0(spi); + MOD_REG_BIT(l, OMAP2_MCSPI_CHCONF_FORCE, cs_active); + mcspi_write_chconf0(spi, l); + } } static void omap2_mcspi_set_master_mode(struct spi_master *master) -- 1.7.1