From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754265AbcB2UWF (ORCPT ); Mon, 29 Feb 2016 15:22:05 -0500 Received: from mail-pa0-f65.google.com ([209.85.220.65]:35014 "EHLO mail-pa0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752251AbcB2UV6 (ORCPT ); Mon, 29 Feb 2016 15:21:58 -0500 Date: Tue, 1 Mar 2016 04:17:14 +0800 From: Han Xu To: Yunhui Cui Cc: Yunhui Cui , "dwmw2@infradead.org" , "computersforpeace@gmail.com" , "han.xu@freescale.com" , "linux-mtd@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , Yao Yuan Subject: Re: [PATCH v2 3/4] mtd:spi-nor:fsl-quadspi:Add fast-read mode support Message-ID: <20160229201714.GA18909@shlinux2.ap.freescale.net> References: <1454326208-4533-1-git-send-email-B56489@freescale.com> <1454326208-4533-3-git-send-email-B56489@freescale.com> <20160217180742.GB17485@shlinux2> <20160226163145.GA2182@shlinux2.ap.freescale.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 29, 2016 at 03:43:36AM +0000, Yunhui Cui wrote: > Hi Han, > > But I don't think QuadSPI driver need to check the m25p,fast-read property again since spi-nor layer has already done that. Adding the property in flash node should work in the same way. > > [Yunhui]: There are three modes in fsl-quadspi driver , fast mode, quad mode, ddr quad read. The last parameter mode of spi_nor_scan() I have to specify . Otherwise, flash is still set to quad mode. If the Nor chip behaves as you said only support fasst-read, the (info->flags & SPI_NOR_QUAD_READ) can only take false path. > spi-nor.c: > > 1419 if (mode == SPI_NOR_QUAD && info->flags & SPI_NOR_QUAD_READ) { > 1420 ret = set_quad_mode(nor, info); > 1421 if (ret) { > 1422 dev_err(dev, "quad mode not supported\n"); > 1423 return ret; > 1424 } > 1425 nor->flash_read = SPI_NOR_QUAD; > 1426 } else if (mode == SPI_NOR_DUAL && info->flags & SPI_NOR_DUAL_READ) { > 1427 nor->flash_read = SPI_NOR_DUAL; > 1428 } > > > Thanks > Yunhui > -----Original Message----- > From: Han Xu [mailto:xhnjupt@gmail.com] > Sent: Saturday, February 27, 2016 12:32 AM > To: Yunhui Cui > Cc: Yunhui Cui; dwmw2@infradead.org; computersforpeace@gmail.com; han.xu@freescale.com; linux-mtd@lists.infradead.org; linux-kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org; Yao Yuan > Subject: Re: [PATCH v2 3/4] mtd:spi-nor:fsl-quadspi:Add fast-read mode support > > On Thu, Feb 25, 2016 at 08:07:22AM +0000, Yunhui Cui wrote: > > Hi Han, > > > > I have provided the options " m25p,fast-read ", because there are probable some flashes can't support quad mode. > > So we should support fast-read mode in our driver. Moreover, There is a option to select fast-read mode in spi_nor.c : > > /* If we were instantiated by DT, use it */ > > if (of_property_read_bool(np, "m25p,fast-read")) > > nor->flash_read = SPI_NOR_FAST; > > Did you have some REAL cases using SPI NOR that only supports upto fast-read with Quad SPI driver? Neither fast-read or normal-read, which is actually more general, supported in the driver, just because I didn't see any REAL cases till now. > > I didn't run against the patch, although IMO it's not that necessary. But I don't think QuadSPI driver need to check the m25p,fast-read property again since spi-nor layer has already done that. Adding the property in flash node should work in the same way. > > > > > Thanks > > Yunhui > > > > -----Original Message----- > > From: Han Xu [mailto:xhnjupt@gmail.com] > > Sent: Thursday, February 18, 2016 2:08 AM > > To: Yunhui Cui > > Cc: dwmw2@infradead.org; computersforpeace@gmail.com; > > han.xu@freescale.com; linux-mtd@lists.infradead.org; > > linux-kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org; > > Yao Yuan > > Subject: Re: [PATCH v2 3/4] mtd:spi-nor:fsl-quadspi:Add fast-read mode > > support > > > > On Mon, Feb 01, 2016 at 07:30:07PM +0800, Yunhui Cui wrote: > > > The qspi driver add generic fast-read mode for different flash > > > venders. There are some different board flash work on different > > > mode, such fast-read, quad-mode. > > > So we have to modify the third entrace parameter of spi_nor_scan(). > > > > > > Signed-off-by: Yunhui Cui > > > --- > > > drivers/mtd/spi-nor/fsl-quadspi.c | 27 +++++++++++++++++++++------ > > > 1 file changed, 21 insertions(+), 6 deletions(-) > > > > > > diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c > > > b/drivers/mtd/spi-nor/fsl-quadspi.c > > > index 9861290..0a31cb1 100644 > > > --- a/drivers/mtd/spi-nor/fsl-quadspi.c > > > +++ b/drivers/mtd/spi-nor/fsl-quadspi.c > > > @@ -389,11 +389,21 @@ static void fsl_qspi_init_lut(struct fsl_qspi *q) > > > /* Read */ > > > lut_base = SEQID_READ * 4; > > > > > > - qspi_writel(q, LUT0(CMD, PAD1, read_op) | LUT1(ADDR, PAD1, addrlen), > > > - base + QUADSPI_LUT(lut_base)); > > > - qspi_writel(q, LUT0(DUMMY, PAD1, read_dm) | > > > - LUT1(FSL_READ, PAD4, rxfifo), > > > - base + QUADSPI_LUT(lut_base + 1)); > > > + if (nor->flash_read == SPI_NOR_FAST) { > > > + qspi_writel(q, LUT0(CMD, PAD1, read_op) | > > > + LUT1(ADDR, PAD1, addrlen), > > > + base + QUADSPI_LUT(lut_base)); > > > + qspi_writel(q, LUT0(DUMMY, PAD1, read_dm) | > > > + LUT1(FSL_READ, PAD1, rxfifo), > > > + base + QUADSPI_LUT(lut_base + 1)); > > > + } else if (nor->flash_read == SPI_NOR_QUAD) { > > > + qspi_writel(q, LUT0(CMD, PAD1, read_op) | > > > + LUT1(ADDR, PAD1, addrlen), > > > + base + QUADSPI_LUT(lut_base)); > > > + qspi_writel(q, LUT0(DUMMY, PAD1, read_dm) | > > > + LUT1(FSL_READ, PAD4, rxfifo), > > > + base + QUADSPI_LUT(lut_base + 1)); > > > + } > > > > > > /* Write enable */ > > > lut_base = SEQID_WREN * 4; > > > @@ -468,6 +478,7 @@ static int fsl_qspi_get_seqid(struct fsl_qspi > > > *q, > > > u8 cmd) { > > > switch (cmd) { > > > case SPINOR_OP_READ_1_1_4: > > > + case SPINOR_OP_READ_FAST: > > > return SEQID_READ; > > > case SPINOR_OP_WREN: > > > return SEQID_WREN; > > > @@ -963,6 +974,7 @@ static int fsl_qspi_probe(struct platform_device *pdev) > > > struct spi_nor *nor; > > > struct mtd_info *mtd; > > > int ret, i = 0; > > > + enum read_mode mode = SPI_NOR_QUAD; > > > > > > q = devm_kzalloc(dev, sizeof(*q), GFP_KERNEL); > > > if (!q) > > > @@ -1064,7 +1076,10 @@ static int fsl_qspi_probe(struct platform_device *pdev) > > > /* set the chip address for READID */ > > > fsl_qspi_set_base_addr(q, nor); > > > > > > - ret = spi_nor_scan(nor, NULL, SPI_NOR_QUAD); > > > + ret = of_property_read_bool(np, "m25p,fast-read"); > > > + mode = (ret) ? SPI_NOR_FAST : SPI_NOR_QUAD; > > > + > > > + ret = spi_nor_scan(nor, NULL, mode); > > > if (ret) > > > goto mutex_failed; > > > > > I understand you want to provide a more generic read mode, but this is a quad spi driver, I prefer to provide the options, either quad read/quad IO read, or just normal read. > > > -- > > > 2.1.0.27.g96db324 > > > > > > > > > ______________________________________________________ > > > Linux MTD discussion mailing list > > > http://lists.infradead.org/mailman/listinfo/linux-mtd/