From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Subject: Re: [PATCH v2 1/2] mtd: spi-nor: Added spi-nor reset function Date: Thu, 9 Feb 2017 16:13:03 +0100 Message-ID: <51e4e497-535f-fd1a-8a20-17183691799b@gmail.com> References: <1486572781-28808-1-git-send-email-kdasu.kdev@gmail.com> <1486572781-28808-2-git-send-email-kdasu.kdev@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: linux-mtd@lists.infradead.org, f.fainelli@gmail.com, bcm-kernel-feedback-list@broadcom.com To: Kamal Dasu , linux-spi@vger.kernel.org, cyrille.pitchen@atmel.com, marex@denx.de, broonie@kernel.org Return-path: In-Reply-To: <1486572781-28808-2-git-send-email-kdasu.kdev@gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-mtd" Errors-To: linux-mtd-bounces+gldm-linux-mtd-36=gmane.org@lists.infradead.org List-Id: linux-spi.vger.kernel.org On 02/08/2017 05:53 PM, Kamal Dasu wrote: > Refactored spi_nor_scan() code to add spi_nor_reset() function that > programs the nand device to: nand device ? > 1) remove flash protection if applicable > 2) set read mode to quad mode if configured such > 3) set the address width based on the flash size and vendor > > On pm resume spi-nor flash may need to be reconfigured after power > reset, there is no need to go through a full spi_nor_scan(), flash > device driver needs to call spi_nor_reset() to reprogram the flash > to its probed state. > > Signed-off-by: Kamal Dasu > --- > drivers/mtd/spi-nor/spi-nor.c | 62 ++++++++++++++++++++++++++++--------------- > include/linux/mtd/spi-nor.h | 21 ++++++++++++++- > 2 files changed, 61 insertions(+), 22 deletions(-) > > diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c > index da7cd69..8e3d8bd 100644 > --- a/drivers/mtd/spi-nor/spi-nor.c > +++ b/drivers/mtd/spi-nor/spi-nor.c > @@ -1312,6 +1312,41 @@ static int spi_nor_check(struct spi_nor *nor) > return 0; > } > > +int spi_nor_reset(struct spi_nor *nor) > +{ > + int ret = 0; > + const struct flash_info *info = nor->info; > + struct device *dev = nor->dev; Does this reset the SPI NOR (as in, really send a reset opcode) ? It doesn't, so the naming is confusing. This should probably be something like "spi_nor_init()" or "spi_nor_setup()" , no ? > + /* > + * Atmel, SST, Intel/Numonyx, and others serial NOR tend to power up > + * with the software protection bits set > + */ > + > + if (JEDEC_MFR(info) == SNOR_MFR_ATMEL || > + JEDEC_MFR(info) == SNOR_MFR_INTEL || > + JEDEC_MFR(info) == SNOR_MFR_SST || > + info->flags & SPI_NOR_HAS_LOCK) { > + write_enable(nor); > + write_sr(nor, 0); > + spi_nor_wait_till_ready(nor); > + } > + > + if (nor->flash_read == SPI_NOR_QUAD) { > + ret = set_quad_mode(nor, info); > + if (ret) { > + dev_err(dev, "quad mode not supported\n"); > + return ret; > + } > + } > + > + if (nor->addr_width == 4 && JEDEC_MFR(info) != SNOR_MFR_SPANSION) > + set_4byte(nor, info, 1); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(spi_nor_reset); > + > int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode) > { > const struct flash_info *info = NULL; > @@ -1357,22 +1392,9 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode) > } > } > > + nor->info = info; > mutex_init(&nor->lock); > > - /* > - * Atmel, SST, Intel/Numonyx, and others serial NOR tend to power up > - * with the software protection bits set > - */ > - > - if (JEDEC_MFR(info) == SNOR_MFR_ATMEL || > - JEDEC_MFR(info) == SNOR_MFR_INTEL || > - JEDEC_MFR(info) == SNOR_MFR_SST || > - info->flags & SPI_NOR_HAS_LOCK) { > - write_enable(nor); > - write_sr(nor, 0); > - spi_nor_wait_till_ready(nor); > - } > - > if (!mtd->name) > mtd->name = dev_name(dev); > mtd->priv = nor; > @@ -1447,11 +1469,6 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode) > > /* Quad/Dual-read mode takes precedence over fast/normal */ > if (mode == SPI_NOR_QUAD && info->flags & SPI_NOR_QUAD_READ) { > - ret = set_quad_mode(nor, info); > - if (ret) { > - dev_err(dev, "quad mode not supported\n"); > - return ret; > - } > nor->flash_read = SPI_NOR_QUAD; > } else if (mode == SPI_NOR_DUAL && info->flags & SPI_NOR_DUAL_READ) { > nor->flash_read = SPI_NOR_DUAL; > @@ -1503,8 +1520,7 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode) > /* No small sector erase for 4-byte command set */ > nor->erase_opcode = SPINOR_OP_SE_4B; > mtd->erasesize = info->sector_size; > - } else > - set_4byte(nor, info, 1); > + } > } else { > nor->addr_width = 3; > } > @@ -1517,6 +1533,10 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode) > > nor->read_dummy = spi_nor_read_dummy_cycles(nor); > > + ret = spi_nor_reset(nor); > + if (ret) > + return ret; > + > dev_info(dev, "%s (%lld Kbytes)\n", info->name, > (long long)mtd->size >> 10); > > diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h > index c425c7b..4733c04 100644 > --- a/include/linux/mtd/spi-nor.h > +++ b/include/linux/mtd/spi-nor.h > @@ -121,6 +121,8 @@ enum spi_nor_option_flags { > SNOR_F_HAS_SR_TB = BIT(1), > }; > > +struct flash_info; > + > /** > * struct spi_nor - Structure for defining a the SPI NOR layer > * @mtd: point to a mtd_info structure > @@ -154,6 +156,7 @@ enum spi_nor_option_flags { > * @priv: the private data > */ > struct spi_nor { > + const struct flash_info *info; > struct mtd_info mtd; > struct mutex lock; > struct device *dev; > @@ -198,12 +201,28 @@ static inline struct device_node *spi_nor_get_flash_node(struct spi_nor *nor) > } > > /** > + * spi_nor_reset() - reset scan the SPI NOR > + * @nor: the spi_nor structure > + * > + * The drivers uses this function to reset the SPI NOR flash device to > + * its initial scanned state, it shall use all nor information set on poweron > + * for the read mode, address width and enabling write mode for certain > + * manufacturers. This would be needed to be called for flash devices that are > + * reset during power management. > + * > + * The chip type name can be provided through the @name parameter. > + * > + * Return: 0 for success, others for failure. > + */ > +int spi_nor_reset(struct spi_nor *nor); > + > +/** > * spi_nor_scan() - scan the SPI NOR > * @nor: the spi_nor structure > * @name: the chip type name > * @mode: the read mode supported by the driver > * > - * The drivers can use this fuction to scan the SPI NOR. > + * The drivers can use this function to scan the SPI NOR. > * In the scanning, it will try to get all the necessary information to > * fill the mtd_info{} and the spi_nor{}. > * > -- Best regards, Marek Vasut ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/