From patchwork Thu Jan 23 10:30:51 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lee Jones X-Patchwork-Id: 23574 Return-Path: X-Original-To: linaro@patches.linaro.org Delivered-To: linaro@patches.linaro.org Received: from mail-ie0-f198.google.com (mail-ie0-f198.google.com [209.85.223.198]) by ip-10-151-82-157.ec2.internal (Postfix) with ESMTPS id A9E67218BD for ; Thu, 23 Jan 2014 10:31:48 +0000 (UTC) Received: by mail-ie0-f198.google.com with SMTP id ar20sf3001316iec.1 for ; Thu, 23 Jan 2014 02:31:48 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:delivered-to:from:to:cc:subject :date:message-id:in-reply-to:references:x-original-sender :x-original-authentication-results:precedence:mailing-list:list-id :list-post:list-help:list-archive:list-unsubscribe; bh=WyEOnooptu5Z+fqVPmKVj/K24bpmnIYNoBybmT3NKYY=; b=R8nE+AELDx4YRu7RZIIsHKDkCyl8ex1jNGFOfl8YVoppaktCMAEw55zXNikhKzFHEv CbM2ss1rqkO3eQwadOyUf9EFIQd0qx7h8soZbgN38Cc2kql9DTxNxCNcvApIr3ATIFlX zhtm87ITGfLnNVUcMiyPw+W9s2MztI4cW2GCN9RSbZvbUzPmQ1VjgqCx6dLkwAvUP7BW cX0RHKpJFKgGJ+Jhyxt8JH/CJAHpV2Em+Pu8db8slKYGDV+LzmcbJajS3uNP3veu1pa3 5vYvnjhpN2qIBjWxCD25Axk3CVJTI1Kd2Y+7KVKR/wrTjRaVwd70x+NG9cla7E3Hcyef hTWg== X-Gm-Message-State: ALoCoQlBc4ROiTfv9l3SIRr3D/mxc7jRex0VkMYNC+ejteSQ6BU1AOXL0AOFFlFk2qI4YmyYyg88 X-Received: by 10.50.32.6 with SMTP id e6mr3379774igi.6.1390473107970; Thu, 23 Jan 2014 02:31:47 -0800 (PST) MIME-Version: 1.0 X-BeenThere: patchwork-forward@linaro.org Received: by 10.49.106.232 with SMTP id gx8ls299567qeb.39.gmail; Thu, 23 Jan 2014 02:31:47 -0800 (PST) X-Received: by 10.58.49.161 with SMTP id v1mr4088030ven.5.1390473107799; Thu, 23 Jan 2014 02:31:47 -0800 (PST) Received: from mail-vc0-f177.google.com (mail-vc0-f177.google.com [209.85.220.177]) by mx.google.com with ESMTPS id sg4si6433863vcb.11.2014.01.23.02.31.47 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 23 Jan 2014 02:31:47 -0800 (PST) Received-SPF: neutral (google.com: 209.85.220.177 is neither permitted nor denied by best guess record for domain of patch+caf_=patchwork-forward=linaro.org@linaro.org) client-ip=209.85.220.177; Received: by mail-vc0-f177.google.com with SMTP id if11so930295vcb.22 for ; Thu, 23 Jan 2014 02:31:47 -0800 (PST) X-Received: by 10.220.103.141 with SMTP id k13mr4075039vco.25.1390473107706; Thu, 23 Jan 2014 02:31:47 -0800 (PST) X-Forwarded-To: patchwork-forward@linaro.org X-Forwarded-For: patch@linaro.org patchwork-forward@linaro.org Delivered-To: patches@linaro.org Received: by 10.220.174.196 with SMTP id u4csp15899vcz; Thu, 23 Jan 2014 02:31:47 -0800 (PST) X-Received: by 10.180.205.162 with SMTP id lh2mr7098142wic.57.1390473106702; Thu, 23 Jan 2014 02:31:46 -0800 (PST) Received: from mail-we0-f179.google.com (mail-we0-f179.google.com [74.125.82.179]) by mx.google.com with ESMTPS id c9si8783722wjy.47.2014.01.23.02.31.46 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 23 Jan 2014 02:31:46 -0800 (PST) Received-SPF: neutral (google.com: 74.125.82.179 is neither permitted nor denied by best guess record for domain of lee.jones@linaro.org) client-ip=74.125.82.179; Received: by mail-we0-f179.google.com with SMTP id w62so928245wes.38 for ; Thu, 23 Jan 2014 02:31:46 -0800 (PST) X-Received: by 10.180.94.67 with SMTP id da3mr7313927wib.38.1390473106146; Thu, 23 Jan 2014 02:31:46 -0800 (PST) Received: from localhost.localdomain ([80.76.198.141]) by mx.google.com with ESMTPSA id ay6sm21257831wjb.23.2014.01.23.02.31.43 for (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 23 Jan 2014 02:31:45 -0800 (PST) From: Lee Jones To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: linus.walleij@linaro.org, dwmw2@infradead.org, linux-mtd@lists.infradead.org, computersforpeace@gmail.com, Angus.Clark@st.com, DCG_UPD_stlinux_kernel@list.st.com, olivier.clergeaud@st.com, Lee Jones Subject: [PATCH RESEND v4 03/37] mtd: st_spi_fsm: Initialise and configure the FSM for normal working conditions Date: Thu, 23 Jan 2014 10:30:51 +0000 Message-Id: <1390473085-24626-4-git-send-email-lee.jones@linaro.org> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1390473085-24626-1-git-send-email-lee.jones@linaro.org> References: <1390473085-24626-1-git-send-email-lee.jones@linaro.org> X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: lee.jones@linaro.org X-Original-Authentication-Results: mx.google.com; spf=neutral (google.com: 209.85.220.177 is neither permitted nor denied by best guess record for domain of patch+caf_=patchwork-forward=linaro.org@linaro.org) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Precedence: list Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org List-ID: X-Google-Group-Id: 836684582541 List-Post: , List-Help: , List-Archive: List-Unsubscribe: , This patch uses default values to initialise a connected flash chip. This includes; a device soft reset, setting of a safe working frequency, a switch into Fast Sequencing Mode, configuring of timing data and a purge of the FIFO. Signed-off-by: Lee Jones --- drivers/mtd/devices/st_spi_fsm.c | 127 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 127 insertions(+) diff --git a/drivers/mtd/devices/st_spi_fsm.c b/drivers/mtd/devices/st_spi_fsm.c index ccee749..5badbe4 100644 --- a/drivers/mtd/devices/st_spi_fsm.c +++ b/drivers/mtd/devices/st_spi_fsm.c @@ -74,6 +74,10 @@ #define SPI_CFG_CS_SETUPHOLD(x) (((x) & 0xff) << 16) #define SPI_CFG_DATA_HOLD(x) (((x) & 0xff) << 24) +#define SPI_CFG_DEFAULT_MIN_CS_HIGH SPI_CFG_MIN_CS_HIGH(0x0AA) +#define SPI_CFG_DEFAULT_CS_SETUPHOLD SPI_CFG_CS_SETUPHOLD(0xA0) +#define SPI_CFG_DEFAULT_DATA_HOLD SPI_CFG_DATA_HOLD(0x00) + /* * Register: SPI_FAST_SEQ_TRANSFER_SIZE */ @@ -185,19 +189,136 @@ #define STFSM_INST_WAIT STFSM_INSTR(STFSM_OPC_WAIT, 0) #define STFSM_INST_STOP STFSM_INSTR(STFSM_OPC_STOP, 0) +#define STFSM_DEFAULT_EMI_FREQ 100000000UL /* 100 MHz */ +#define STFSM_DEFAULT_WR_TIME (STFSM_DEFAULT_EMI_FREQ * (15/1000)) /* 15ms */ + +#define STFSM_FLASH_SAFE_FREQ 10000000UL /* 10 MHz */ + struct stfsm { struct device *dev; void __iomem *base; struct resource *region; struct mtd_info mtd; struct mutex lock; + + uint32_t fifo_dir_delay; }; +static inline uint32_t stfsm_fifo_available(struct stfsm *fsm) +{ + return (readl(fsm->base + SPI_FAST_SEQ_STA) >> 5) & 0x7f; +} + +static void stfsm_clear_fifo(struct stfsm *fsm) +{ + uint32_t avail; + + for (;;) { + avail = stfsm_fifo_available(fsm); + if (!avail) + break; + + while (avail) { + readl(fsm->base + SPI_FAST_SEQ_DATA_REG); + avail--; + } + } +} + +static int stfsm_set_mode(struct stfsm *fsm, uint32_t mode) +{ + int ret, timeout = 10; + + /* Wait for controller to accept mode change */ + while (--timeout) { + ret = readl(fsm->base + SPI_STA_MODE_CHANGE); + if (ret & 0x1) + break; + udelay(1); + } + + if (!timeout) + return -EBUSY; + + writel(mode, fsm->base + SPI_MODESELECT); + + return 0; +} + +static void stfsm_set_freq(struct stfsm *fsm, uint32_t spi_freq) +{ + uint32_t emi_freq; + uint32_t clk_div; + + /* TODO: Make this dynamic */ + emi_freq = STFSM_DEFAULT_EMI_FREQ; + + /* + * Calculate clk_div - values between 2 and 128 + * Multiple of 2, rounded up + */ + clk_div = 2 * DIV_ROUND_UP(emi_freq, 2 * spi_freq); + if (clk_div < 2) + clk_div = 2; + else if (clk_div > 128) + clk_div = 128; + + /* + * Determine a suitable delay for the IP to complete a change of + * direction of the FIFO. The required delay is related to the clock + * divider used. The following heuristics are based on empirical tests, + * using a 100MHz EMI clock. + */ + if (clk_div <= 4) + fsm->fifo_dir_delay = 0; + else if (clk_div <= 10) + fsm->fifo_dir_delay = 1; + else + fsm->fifo_dir_delay = DIV_ROUND_UP(clk_div, 10); + + dev_dbg(fsm->dev, "emi_clk = %uHZ, spi_freq = %uHZ, clk_div = %u\n", + emi_freq, spi_freq, clk_div); + + writel(clk_div, fsm->base + SPI_CLOCKDIV); +} + +static int stfsm_init(struct stfsm *fsm) +{ + int ret; + + /* Perform a soft reset of the FSM controller */ + writel(SEQ_CFG_SWRESET, fsm->base + SPI_FAST_SEQ_CFG); + udelay(1); + writel(0, fsm->base + SPI_FAST_SEQ_CFG); + + /* Set clock to 'safe' frequency initially */ + stfsm_set_freq(fsm, STFSM_FLASH_SAFE_FREQ); + + /* Switch to FSM */ + ret = stfsm_set_mode(fsm, SPI_MODESELECT_FSM); + if (ret) + return ret; + + /* Set timing parameters */ + writel(SPI_CFG_DEVICE_ST | + SPI_CFG_DEFAULT_MIN_CS_HIGH | + SPI_CFG_DEFAULT_CS_SETUPHOLD | + SPI_CFG_DEFAULT_DATA_HOLD, + fsm->base + SPI_CONFIGDATA); + writel(STFSM_DEFAULT_WR_TIME, fsm->base + SPI_STATUS_WR_TIME_REG); + + /* Clear FIFO, just in case */ + stfsm_clear_fifo(fsm); + + return 0; +} + static int stfsm_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; struct resource *res; struct stfsm *fsm; + int ret; if (!np) { dev_err(&pdev->dev, "No DT found\n"); @@ -234,6 +355,12 @@ static int stfsm_probe(struct platform_device *pdev) mutex_init(&fsm->lock); + ret = stfsm_init(fsm); + if (ret) { + dev_err(&pdev->dev, "Failed to initialise FSM Controller\n"); + return ret; + } + platform_set_drvdata(pdev, fsm); fsm->mtd.dev.parent = &pdev->dev;