Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752732AbbHUHMU (ORCPT ); Fri, 21 Aug 2015 03:12:20 -0400 Received: from s159.web-hosting.com ([68.65.121.203]:42383 "EHLO s159.web-hosting.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752575AbbHUHMS convert rfc822-to-8bit (ORCPT ); Fri, 21 Aug 2015 03:12:18 -0400 MIME-Version: 1.0 In-Reply-To: References: <1439978205-6092-1-git-send-email-jteki@openedev.com> <1439978205-6092-3-git-send-email-jteki@openedev.com> Date: Fri, 21 Aug 2015 12:42:12 +0530 Message-ID: Subject: Re: [PATCH 3/3] mtd: spi-nor: sf: Add clear flag status register support From: Jagan Teki To: Hou Zhiqiang Cc: "linux-mtd@lists.infradead.org" , Hu Vincent , Brian Norris , David Woodhouse , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT X-OutGoing-Spam-Status: No, score=-2.9 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - server159.web-hosting.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - openedev.com X-Get-Message-Sender-Via: server159.web-hosting.com: authenticated_id: jteki@openedev.com X-Source: X-Source-Args: X-Source-Dir: X-From-Rewrite: unmodified, already matched Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4695 Lines: 112 Hi Zhiqiang, On 20 August 2015 at 08:36, Hou Zhiqiang wrote: > Hello Jagan, > >> -----Original Message----- >> From: Jagan Teki [mailto:jteki@openedev.com] >> Sent: 2015年8月20日 1:49 >> To: Hou Zhiqiang-B48286 >> Cc: linux-mtd@lists.infradead.org; Hu Mingkai-B21284; Brian Norris; David >> Woodhouse; linux-kernel@vger.kernel.org >> Subject: Re: [PATCH 3/3] mtd: spi-nor: sf: Add clear flag status register >> support >> >> Hi Zhiqiang, >> >> On 19 August 2015 at 17:42, Hou Zhiqiang wrote: >> > Hi Jagan, >> > >> >> -----Original Message----- >> >> From: Jagan Teki [mailto:jteki@openedev.com] >> >> Sent: 2015年8月19日 17:57 >> >> To: linux-mtd@lists.infradead.org >> >> Cc: linux-kernel@vger.kernel.org; Jagan Teki; Hou Zhiqiang-B48286; Hu >> >> Mingkai-B21284; David Woodhouse; Brian Norris >> >> Subject: [PATCH 3/3] mtd: spi-nor: sf: Add clear flag status register >> >> support >> >> >> >> The clear flag status register operation was required by Micron >> >> SPI-NOR chips, which support FSR. And if an error bit of FSR have >> >> been set like protection, voltage, erase, and program, it must be >> >> cleared by the clear FSR operation. >> >> >> >> Signed-off-by: Jagan Teki >> >> Cc: Hou Zhiqiang >> >> Cc: Mingkai.Hu >> >> Cc: David Woodhouse >> >> Cc: Brian Norris >> >> --- >> >> drivers/mtd/spi-nor/spi-nor.c | 35 +++++++++++++++++++++++++++++++--- >> - >> >> include/linux/mtd/spi-nor.h | 9 +++++++++ >> >> 2 files changed, 40 insertions(+), 4 deletions(-) >> >> >> >> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi- >> >> nor.c index f954d03..c5c472d5 100644 >> >> --- a/drivers/mtd/spi-nor/spi-nor.c >> >> +++ b/drivers/mtd/spi-nor/spi-nor.c >> >> @@ -100,6 +100,28 @@ static int read_fsr(struct spi_nor *nor) } >> >> >> >> /* >> >> + * Read the clear flag status register. >> >> + * The clear flag status register operation was required by Micron >> >> + * SPI-NOR chips, which support FSR. And if an error bit of FSR >> >> + * have been set like protection, voltage, erase, and program, >> >> + * it must be cleared by the clear FSR operation. >> >> + * Returns zero for FSR bits cleared and negative if error occurred. >> >> + */ >> >> +static int read_cfsr(struct spi_nor *nor) { >> >> + int ret; >> >> + u8 val; >> >> + >> >> + ret = nor->read_reg(nor, SPINOR_OP_RDCFSR, &val, 1); >> > >> > There should be a write_reg instead of read_reg. >> > There isn’t a register named CFSR, and the command SPINOR_OP_RDCFSR is >> > used to clear the FSR, another words reset FSR to default value. >> >> Yes, SPINOR_OP_RDCFSR is clear flag status register, for clearing errors >> bits on fsr we need to read cfsr once. >> > > Sorry, I'm not clear for this operation. Please correct me if I'm wrong. > As far as I understand, this command is used to reset the FSR. Does a value > Will be read back? And there is not the register CFSR, so I don't know which > register will be read by SPINOR_OP_RDCFSR? Sorry for the confusion in previous email. If there is any error bits set during FSR operation, those will reset back to original values by reading CFSR ie means the bits on flag status register revert back to original state, so-that the flag status register is ready for next FSR operation. I have defined this, SPINOR_OP_RDCFSR on the patch diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h index c5a58c4..36c1681 100644 --- a/include/linux/mtd/spi-nor.h +++ b/include/linux/mtd/spi-nor.h @@ -35,6 +35,7 @@ #define SPINOR_OP_RDID 0x9f /* Read JEDEC ID */ #define SPINOR_OP_RDCR 0x35 /* Read configuration register */ #define SPINOR_OP_RDFSR 0x70 /* Read flag status register */ +#define SPINOR_OP_RDCFSR 0x50 /* Read clear flag status register */ For more information pls- refer flash datasheet[1] Page, 29: about fsr Page, 41: about cfsr [1] https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0CCIQFjABahUKEwjTwY3zzbnHAhXVj44KHdiWDVU&url=https%3A%2F%2Fwww.micron.com%2F~%2Fmedia%2Fdocuments%2Fproducts%2Fdata-sheet%2Fnor-flash%2Fserial-nor%2Fn25q%2Fn25q_512mb_1ce_3v_65nm.pdf&ei=Uc3WVZPVCNWfugTYrbaoBQ&usg=AFQjCNEN4dLie4U9OTSbNxN-h9jyN9InDQ&sig2=vRQTvlkbgsgJw1Fy9z1K8A thanks! -- Jagan | openedev. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/