From patchwork Tue Sep 16 11:25:05 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Grygorii Strashko X-Patchwork-Id: 390046 Return-Path: X-Original-To: incoming-dt@patchwork.ozlabs.org Delivered-To: patchwork-incoming-dt@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id EE3C8140096 for ; Tue, 16 Sep 2014 21:25:37 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753169AbaIPLZg (ORCPT ); Tue, 16 Sep 2014 07:25:36 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:47647 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752061AbaIPLZf (ORCPT ); Tue, 16 Sep 2014 07:25:35 -0400 Received: from dflxv15.itg.ti.com ([128.247.5.124]) by bear.ext.ti.com (8.13.7/8.13.7) with ESMTP id s8GBPArR031661; Tue, 16 Sep 2014 06:25:10 -0500 Received: from DFLE73.ent.ti.com (dfle73.ent.ti.com [128.247.5.110]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id s8GBP9Ek031620; Tue, 16 Sep 2014 06:25:09 -0500 Received: from dflp33.itg.ti.com (10.64.6.16) by DFLE73.ent.ti.com (128.247.5.110) with Microsoft SMTP Server id 14.3.174.1; Tue, 16 Sep 2014 06:25:09 -0500 Received: from localhost (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp33.itg.ti.com (8.14.3/8.13.8) with ESMTP id s8GBP8w9009256; Tue, 16 Sep 2014 06:25:09 -0500 From: Grygorii Strashko To: , Mark Brown , CC: , , , Murali Karicheri , Grygorii Strashko Subject: [RESEND PATCH v3] spi: davinci: add support for adding delay between word's transmissions Date: Tue, 16 Sep 2014 14:25:05 +0300 Message-ID: <1410866705-13520-1-git-send-email-grygorii.strashko@ti.com> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org From: Murali Karicheri This patch adds ability to configure delay between transmission of words over SPI bus if it's required by SPI slave devices. New optional SPI slave property: - ti,spi-word-delay : delay between transmission of words (SPIFMTn.WDELAY, SPIDAT1.WDEL) Signed-off-by: Murali Karicheri Signed-off-by: Grygorii Strashko --- Rebased on top of: spi.git/for-next + "[PATCH] spi: davinci: remove empty function davinci_spi_cleanup" http://www.spinics.net/lists/arm-kernel/msg362811.html v3: http://www.spinics.net/lists/devicetree/msg49141.html v2: http://www.spinics.net/lists/devicetree/msg48514.html v1: http://www.spinics.net/lists/linux-spi/msg01609.html .../devicetree/bindings/spi/spi-davinci.txt | 30 ++++++++++++ drivers/spi/spi-davinci.c | 55 +++++++++++++++++++--- 2 files changed, 78 insertions(+), 7 deletions(-) diff --git a/Documentation/devicetree/bindings/spi/spi-davinci.txt b/Documentation/devicetree/bindings/spi/spi-davinci.txt index f80887b..12ecfe9 100644 --- a/Documentation/devicetree/bindings/spi/spi-davinci.txt +++ b/Documentation/devicetree/bindings/spi/spi-davinci.txt @@ -1,5 +1,10 @@ Davinci SPI controller device bindings +Links on DM: +Keystone 2 - http://www.ti.com/lit/ug/sprugp2a/sprugp2a.pdf +dm644x - http://www.ti.com/lit/ug/sprue32a/sprue32a.pdf +OMAP-L138/da830 - http://www.ti.com/lit/ug/spruh77a/spruh77a.pdf + Required properties: - #address-cells: number of cells required to define a chip select address on the SPI bus. Should be set to 1. @@ -24,6 +29,30 @@ Optional: cs-gpios = <0>, <0>, <0>, <&gpio1 30 0>, <&gpio1 31 0>; where first three are internal CS and last two are GPIO CS. +Optional properties for slave devices: +SPI slave nodes can contain the following properties. +Not all SPI Peripherals from Texas Instruments support this. +Please check SPI peripheral documentation for a device before using these. + +- ti,spi-wdelay : delay between transmission of words + (SPIFMTn.WDELAY, SPIDAT1.WDEL) must be specified in number of SPI module + clock periods. + + delay = WDELAY * SPI_module_clock_period + 2 * SPI_module_clock_period + +Below is timing diagram which shows functional meaning of +"ti,spi-wdelay" parameter. + + +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +SPI_CLK | | | | | | | | | | | | | | | | + +----------+ +-+ +-+ +-+ +-+ +---------------------------+ +-+ +-+ +- + +SPI_SOMI/SIMO+-----------------+ +----------- + +----------+ word1 +---------------------------+word2 + +-----------------+ +----------- + WDELAY + <--------------------------> + Example of a NOR flash slave device (n25q032) connected to DaVinci SPI controller device over the SPI bus. @@ -43,6 +72,7 @@ spi0:spi@20BF0000 { compatible = "st,m25p32"; spi-max-frequency = <25000000>; reg = <0>; + ti,spi-wdelay = <8>; partition@0 { label = "u-boot-spl"; diff --git a/drivers/spi/spi-davinci.c b/drivers/spi/spi-davinci.c index 134fb6e..ada3891 100644 --- a/drivers/spi/spi-davinci.c +++ b/drivers/spi/spi-davinci.c @@ -65,6 +65,7 @@ /* SPIDAT1 (upper 16 bit defines) */ #define SPIDAT1_CSHOLD_MASK BIT(12) +#define SPIDAT1_WDEL BIT(10) /* SPIGCR1 */ #define SPIGCR1_CLKMOD_MASK BIT(1) @@ -209,6 +210,7 @@ static void davinci_spi_chipselect(struct spi_device *spi, int value) { struct davinci_spi *dspi; struct davinci_spi_platform_data *pdata; + struct davinci_spi_config *spicfg = spi->controller_data; u8 chip_sel = spi->chip_select; u16 spidat1 = CS_DEFAULT; bool gpio_chipsel = false; @@ -223,6 +225,10 @@ static void davinci_spi_chipselect(struct spi_device *spi, int value) gpio = spi->cs_gpio; } + /* program delay transfers if tx_delay is non zero */ + if (spicfg->wdelay) + spidat1 |= SPIDAT1_WDEL; + /* * Board specific chip select logic decides the polarity and cs * line for the controller @@ -237,9 +243,9 @@ static void davinci_spi_chipselect(struct spi_device *spi, int value) spidat1 |= SPIDAT1_CSHOLD_MASK; spidat1 &= ~(0x1 << chip_sel); } - - iowrite16(spidat1, dspi->base + SPIDAT1 + 2); } + + iowrite16(spidat1, dspi->base + SPIDAT1 + 2); } /** @@ -285,7 +291,7 @@ static int davinci_spi_setup_transfer(struct spi_device *spi, int prescale; dspi = spi_master_get_devdata(spi->master); - spicfg = (struct davinci_spi_config *)spi->controller_data; + spicfg = spi->controller_data; if (!spicfg) spicfg = &davinci_spi_default_cfg; @@ -333,6 +339,14 @@ static int davinci_spi_setup_transfer(struct spi_device *spi, spifmt |= SPIFMT_PHASE_MASK; /* + * Assume wdelay is used only on SPI peripherals that has this field + * in SPIFMTn register and when it's configured from board file or DT. + */ + if (spicfg->wdelay) + spifmt |= ((spicfg->wdelay << SPIFMT_WDELAY_SHIFT) + & SPIFMT_WDELAY_MASK); + + /* * Version 1 hardware supports two basic SPI modes: * - Standard SPI mode uses 4 pins, with chipselect * - 3 pin SPI is a 4 pin variant without CS (SPI_NO_CS) @@ -349,9 +363,6 @@ static int davinci_spi_setup_transfer(struct spi_device *spi, u32 delay = 0; - spifmt |= ((spicfg->wdelay << SPIFMT_WDELAY_SHIFT) - & SPIFMT_WDELAY_MASK); - if (spicfg->odd_parity) spifmt |= SPIFMT_ODD_PARITY_MASK; @@ -383,6 +394,26 @@ static int davinci_spi_setup_transfer(struct spi_device *spi, return 0; } +static int davinci_spi_of_setup(struct spi_device *spi) +{ + struct davinci_spi_config *spicfg = spi->controller_data; + struct device_node *np = spi->dev.of_node; + u32 prop; + + if (spicfg == NULL && np) { + spicfg = kzalloc(sizeof(*spicfg), GFP_KERNEL); + if (!spicfg) + return -ENOMEM; + *spicfg = davinci_spi_default_cfg; + /* override with dt configured values */ + if (!of_property_read_u32(np, "ti,spi-wdelay", &prop)) + spicfg->wdelay = (u8)prop; + spi->controller_data = spicfg; + } + + return 0; +} + /** * davinci_spi_setup - This functions will set default transfer method * @spi: spi device on which data transfer to be done @@ -433,7 +464,16 @@ static int davinci_spi_setup(struct spi_device *spi) else clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_LOOPBACK_MASK); - return retval; + return davinci_spi_of_setup(spi); +} + +static void davinci_spi_cleanup(struct spi_device *spi) +{ + struct davinci_spi_config *spicfg = spi->controller_data; + + spi->controller_data = NULL; + if (spi->dev.of_node) + kfree(spicfg); } static int davinci_spi_check_error(struct davinci_spi *dspi, int int_status) @@ -947,6 +987,7 @@ static int davinci_spi_probe(struct platform_device *pdev) master->num_chipselect = pdata->num_chipselect; master->bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 16); master->setup = davinci_spi_setup; + master->cleanup = davinci_spi_cleanup; dspi->bitbang.chipselect = davinci_spi_chipselect; dspi->bitbang.setup_transfer = davinci_spi_setup_transfer;