From patchwork Wed Nov 17 10:44:17 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sekhar Nori X-Patchwork-Id: 332021 Received: from arroyo.ext.ti.com (arroyo.ext.ti.com [192.94.94.40]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id oAHAxDuN014589 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 17 Nov 2010 10:59:51 GMT Received: from dlep33.itg.ti.com ([157.170.170.112]) by arroyo.ext.ti.com (8.13.7/8.13.7) with ESMTP id oAHAwmuM013648 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 17 Nov 2010 04:59:07 -0600 Received: from linux.omap.com (localhost [127.0.0.1]) by dlep33.itg.ti.com (8.13.7/8.13.7) with ESMTP id oAHAwlq7020236 for ; Wed, 17 Nov 2010 04:58:48 -0600 (CST) Received: from linux.omap.com (localhost [127.0.0.1]) by linux.omap.com (Postfix) with ESMTP id C5F4D8063A for ; Wed, 17 Nov 2010 04:58:46 -0600 (CST) X-Original-To: davinci-linux-open-source@linux.davincidsp.com Delivered-To: davinci-linux-open-source@linux.davincidsp.com Received: from dbdp31.itg.ti.com (dbdp31.itg.ti.com [172.24.170.98]) by linux.omap.com (Postfix) with ESMTP id 1AE6580647 for ; Wed, 17 Nov 2010 04:44:34 -0600 (CST) Received: from psplinux051.india.ti.com (localhost [127.0.0.1]) by dbdp31.itg.ti.com (8.13.8/8.13.8) with ESMTP id oAHAiVNZ021944; Wed, 17 Nov 2010 16:14:32 +0530 (IST) Received: from psplinux051.india.ti.com (localhost [127.0.0.1]) by psplinux051.india.ti.com (8.13.1/8.13.1) with ESMTP id oAHAiQdS030572; Wed, 17 Nov 2010 16:14:26 +0530 Received: (from a0875516@localhost) by psplinux051.india.ti.com (8.13.1/8.13.1/Submit) id oAHAiQWx030569; Wed, 17 Nov 2010 16:14:26 +0530 From: Sekhar Nori To: spi-devel-general@lists.sourceforge.net Subject: [PATCH 45/49] spi: davinci: add additional comments Date: Wed, 17 Nov 2010 16:14:17 +0530 Message-Id: <1289990661-30126-46-git-send-email-nsekhar@ti.com> X-Mailer: git-send-email 1.6.2.4 In-Reply-To: <1289990661-30126-45-git-send-email-nsekhar@ti.com> References: <1289990661-30126-1-git-send-email-nsekhar@ti.com> <1289990661-30126-2-git-send-email-nsekhar@ti.com> <1289990661-30126-3-git-send-email-nsekhar@ti.com> <1289990661-30126-4-git-send-email-nsekhar@ti.com> <1289990661-30126-5-git-send-email-nsekhar@ti.com> <1289990661-30126-6-git-send-email-nsekhar@ti.com> <1289990661-30126-7-git-send-email-nsekhar@ti.com> <1289990661-30126-8-git-send-email-nsekhar@ti.com> <1289990661-30126-9-git-send-email-nsekhar@ti.com> <1289990661-30126-10-git-send-email-nsekhar@ti.com> <1289990661-30126-11-git-send-email-nsekhar@ti.com> <1289990661-30126-12-git-send-email-nsekhar@ti.com> <1289990661-30126-13-git-send-email-nsekhar@ti.com> <1289990661-30126-14-git-send-email-nsekhar@ti.com> <1289990661-30126-15-git-send-email-nsekhar@ti.com> <1289990661-30126-16-git-send-email-nsekhar@ti.com> <1289990661-30126-17-git-send-email-nsekhar@ti.com> <1289990661-30126-18-git-send-email-nsekhar@ti.com> <1289990661-30126-19-git-send-email-nsekhar@ti.com> <1289990661-30126-20-git-send-email-nsekhar@ti.com> <1289990661-30126-21-git-send-email-nsekhar@ti.com> <1289990661-30126-22-git-send-email-nsekhar@ti.com> <1289990661-30126-23-git-send-email-nsekhar@ti.com> <1289990661-30126-24-git-send-email-nsekhar@ti.com> <1289990661-30126-25-git-send-email-nsekhar@ti.com> <1289990661-30126-26-git-send-email-nsekhar@ti.com> <1289990661-30126-27-git-send-email-nsekhar@ti.com> <1289990661-30126-28-git-send-email-nsekhar@ti.com> <1289990661-30126-29-git-send-email-nsekhar@ti.com> <1289990661-30126-30-git-send-email-nsekhar@ti.com> <1289990661-30126-31-git-send-email-nsekhar@ti.com> <1289990661-30126-32-git-send-email-nsekhar@ti.com> <1289990661-30126-33-git-send-email-nsekhar@ti.com> <1289990661-30126-34-git-send-email-nsekhar@ti.com> <1289990661-30126-35-git-send-email-nsekhar@ti.com> <1289990661-30126-36-git-send-email-nsekhar@ti.com> <1289990661-30126-37-git-send-email-nsekhar@ti.com> <1289990661-30126-38-git-send-email-nsekhar@ti.com> <1289990661-30126-39-git-send-email-nsekhar@ti.com> <1289990661-30126-40-git-send-email-nsekhar@ti.com> <1289990661-30126-41-git-send-email-nsekhar@ti.com> <1289990661-30126-42-git-send-email-nsekhar@ti.com> <1289990661-30126-43-git-send-email-nsekhar@ti.com> <1289990661-30126-44-git-send-email-nsekhar@ti.com> <1289990661-30126-45-git-send-email-nsekhar@ti.com> Cc: Grant Likely , davinci-linux-open-source@linux.davincidsp.com, David Brownell X-BeenThere: davinci-linux-open-source@linux.davincidsp.com X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: davinci-linux-open-source-bounces+patchwork-davinci=patchwork.kernel.org@linux.davincidsp.com Errors-To: davinci-linux-open-source-bounces+patchwork-davinci=patchwork.kernel.org@linux.davincidsp.com X-Greylist: Sender succeeded STARTTLS authentication, not delayed by milter-greylist-4.2.3 (demeter1.kernel.org [140.211.167.41]); Wed, 17 Nov 2010 10:59:52 +0000 (UTC) diff --git a/arch/arm/mach-davinci/include/mach/spi.h b/arch/arm/mach-davinci/include/mach/spi.h index 1f8b786..38f4da5 100644 --- a/arch/arm/mach-davinci/include/mach/spi.h +++ b/arch/arm/mach-davinci/include/mach/spi.h @@ -26,6 +26,20 @@ enum { SPI_VERSION_2, /* For DA8xx */ }; +/** + * davinci_spi_platform_data - Platform data for SPI master device on DaVinci + * + * @version: version of the SPI IP. Different DaVinci devices have slightly + * varying versions of the same IP. + * @num_chipselect: number of chipselects supported by this SPI master + * @intr_line: interrupt line used to connect the SPI IP to the ARM interrupt + * controller withn the SoC. Possible values are 0 and 1. + * @chip_sel: list of GPIOs which can act as chip-selects for the SPI. + * SPI_INTERN_CS denotes internal SPI chip-select. Not necessary + * to populate if all chip-selects are internal. + * @cshold_bug: set this to true if the SPI controller on your chip requires + * a write to CSHOLD bit in between transfers (like in DM355). + */ struct davinci_spi_platform_data { u8 version; u8 num_chipselect; @@ -34,6 +48,24 @@ struct davinci_spi_platform_data { bool cshold_bug; }; +/** + * davinci_spi_config - Per-chip-select configuration for SPI slave devices + * + * @wdelay: amount of delay between transmissions. Measured in number of + * SPI module clocks. + * @odd_parity: polarity of parity flag at the end of transmit data stream. + * 0 - odd parity, 1 - even parity. + * @parity_enable: enable transmission of parity at end of each transmit + * data stream. + * @io_type: type of IO transfer. Choose between polled, interrupt and DMA. + * @timer_disable: disable chip-select timers (setup and hold) + * @c2tdelay: chip-select setup time. Measured in number of SPI module clocks. + * @t2cdelay: chip-select hold time. Measured in number of SPI module clocks. + * @t2edelay: transmit data finished to SPI ENAn pin inactive time. Measured + * in number of SPI clocks. + * @c2edelay: chip-select active to SPI ENAn signal active time. Measured in + * number of SPI clocks. + */ struct davinci_spi_config { u8 wdelay; u8 odd_parity; diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c index 2ec5fd2..f40f1be 100644 --- a/drivers/spi/davinci_spi.c +++ b/drivers/spi/davinci_spi.c @@ -787,6 +787,13 @@ rx_dma_failed: /** * davinci_spi_probe - probe function for SPI Master Controller * @pdev: platform_device structure which contains plateform specific data + * + * According to Linux Device Model this function will be invoked by Linux + * with platform_device struct which contains the device specific info. + * This function will map the SPI controller's memory, register IRQ, + * Reset SPI controller and setting its registers to default value. + * It will invoke spi_bitbang_start to create work queue so that client driver + * can register transfer method to work queue. */ static int davinci_spi_probe(struct platform_device *pdev) {