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From: <Tudor.Ambarus@microchip.com>
To: <yangyicong@hisilicon.com>, <linux-mtd@lists.infradead.org>
Cc: vigneshr@ti.com, sergei.shtylyov@cogentembedded.com,
	richard@nod.at, me@yadavpratyush.com, john.garry@huawei.com,
	linuxarm@huawei.com, alexander.sverdlin@nokia.com,
	miquel.raynal@bootlin.com, p.yadav@ti.com
Subject: Re: [PATCH 1/2] mtd: spi-nor: Add capability to disable flash quad mode
Date: Thu, 2 Jul 2020 11:07:43 +0000	[thread overview]
Message-ID: <7cb989be-3621-ff45-5277-1e82968128b2@microchip.com> (raw)
In-Reply-To: <1592312547-19239-2-git-send-email-yangyicong@hisilicon.com>

On 6/16/20 4:02 PM, Yicong Yang wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> Previous we didn't provide a way to disable the flash's quad mode.
> Which means we cannot do some cleanup works when to remove or
> poweroff the flash, like what set 4-byte address mode does in
> spi_nor_restore().
> 
> Add the capability to disable the flash quad mode, by introducing
> an enable flag in the flash parameters quad_enable() hooks and
> related functions.
> 
> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
> Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
> ---
>  drivers/mtd/spi-nor/core.c | 55 +++++++++++++++++++++++++++++++---------------
>  drivers/mtd/spi-nor/core.h | 10 ++++-----
>  2 files changed, 42 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
> index 0369d98..ad5498f 100644
> --- a/drivers/mtd/spi-nor/core.c
> +++ b/drivers/mtd/spi-nor/core.c
> @@ -1907,15 +1907,16 @@ static int spi_nor_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
>  }
> 
>  /**
> - * spi_nor_sr1_bit6_quad_enable() - Set the Quad Enable BIT(6) in the Status
> - * Register 1.
> + * spi_nor_sr1_bit6_quad_enable() - Set/Unset the Quad Enable BIT(6) in the
> + *                                  Status Register 1.
>   * @nor:       pointer to a 'struct spi_nor'
> + * @enable:    true to enter quad mode. false to leave quad mode.

s/enter/enable and s/leave/disable? s/quad mode/Quad Mode
>   *
>   * Bit 6 of the Status Register 1 is the QE bit for Macronix like QSPI memories.
>   *
>   * Return: 0 on success, -errno otherwise.
>   */
> -int spi_nor_sr1_bit6_quad_enable(struct spi_nor *nor)
> +int spi_nor_sr1_bit6_quad_enable(struct spi_nor *nor, bool enable)
>  {
>         int ret;
> 
> @@ -1923,45 +1924,58 @@ int spi_nor_sr1_bit6_quad_enable(struct spi_nor *nor)
>         if (ret)
>                 return ret;
> 
> -       if (nor->bouncebuf[0] & SR1_QUAD_EN_BIT6)
> +       if ((enable && (nor->bouncebuf[0] & SR1_QUAD_EN_BIT6)) ||
> +           (!enable || !(nor->bouncebuf[0] & SR1_QUAD_EN_BIT6)))

there's a bug here, I think that you wanted:
(!enable && !(nor->bouncebuf[0] & SR1_QUAD_EN_BIT6))

>                 return 0;
> 
> -       nor->bouncebuf[0] |= SR1_QUAD_EN_BIT6;
> +       if (enable)
> +               nor->bouncebuf[0] |= SR1_QUAD_EN_BIT6;
> +       else
> +               nor->bouncebuf[0] &= ~SR1_QUAD_EN_BIT6;
> 
>         return spi_nor_write_sr1_and_check(nor, nor->bouncebuf[0]);
>  }
> 
>  /**
> - * spi_nor_sr2_bit1_quad_enable() - set the Quad Enable BIT(1) in the Status
> - * Register 2.
> + * spi_nor_sr2_bit1_quad_enable() - set/unset the Quad Enable BIT(1) in the
> + *                                  Status Register 2.
>   * @nor:       pointer to a 'struct spi_nor'.
> + * @enable:    true to enter quad mode. false to leave quad mode.

ditto

>   *
>   * Bit 1 of the Status Register 2 is the QE bit for Spansion like QSPI memories.
>   *
>   * Return: 0 on success, -errno otherwise.
>   */
> -int spi_nor_sr2_bit1_quad_enable(struct spi_nor *nor)
> +int spi_nor_sr2_bit1_quad_enable(struct spi_nor *nor, bool enable)
>  {
>         int ret;
> 
>         if (nor->flags & SNOR_F_NO_READ_CR)
> -               return spi_nor_write_16bit_cr_and_check(nor, SR2_QUAD_EN_BIT1);
> +               return spi_nor_write_16bit_cr_and_check(nor,
> +                                               enable ? SR2_QUAD_EN_BIT1 : 0);
> 
>         ret = spi_nor_read_cr(nor, nor->bouncebuf);
>         if (ret)
>                 return ret;
> 
> -       if (nor->bouncebuf[0] & SR2_QUAD_EN_BIT1)
> +       if ((enable && (nor->bouncebuf[0] & SR2_QUAD_EN_BIT1)) ||
> +           !(enable || (nor->bouncebuf[0] & SR2_QUAD_EN_BIT1)))

I am too finding the following line more readable. Would you change it?

(!enable && !(nor->bouncebuf[0] & SR2_QUAD_EN_BIT1))

>                 return 0;
> 
>         nor->bouncebuf[0] |= SR2_QUAD_EN_BIT1;

you forgot to drop this line

> 
> +       if (enable)
> +               nor->bouncebuf[0] |= SR2_QUAD_EN_BIT1;
> +       else
> +               nor->bouncebuf[0] &= ~SR2_QUAD_EN_BIT1;
> +
>         return spi_nor_write_16bit_cr_and_check(nor, nor->bouncebuf[0]);
>  }
> 
>  /**
> - * spi_nor_sr2_bit7_quad_enable() - set QE bit in Status Register 2.
> + * spi_nor_sr2_bit7_quad_enable() - set/unset QE bit in Status Register 2.
>   * @nor:       pointer to a 'struct spi_nor'
> + * @enable:    true to enter quad mode. false to leave quad mode.

ditto

>   *
>   * Set the Quad Enable (QE) bit in the Status Register 2.
>   *
> @@ -1971,7 +1985,7 @@ int spi_nor_sr2_bit1_quad_enable(struct spi_nor *nor)
>   *
>   * Return: 0 on success, -errno otherwise.
>   */
> -int spi_nor_sr2_bit7_quad_enable(struct spi_nor *nor)
> +int spi_nor_sr2_bit7_quad_enable(struct spi_nor *nor, bool enable)
>  {
>         u8 *sr2 = nor->bouncebuf;
>         int ret;
> @@ -1981,11 +1995,15 @@ int spi_nor_sr2_bit7_quad_enable(struct spi_nor *nor)
>         ret = spi_nor_read_sr2(nor, sr2);
>         if (ret)
>                 return ret;
> -       if (*sr2 & SR2_QUAD_EN_BIT7)
> +       if ((enable && (*sr2 & SR2_QUAD_EN_BIT7)) ||
> +           !(enable || (*sr2 & SR2_QUAD_EN_BIT7)))

(!enable && !(*sr2 & SR2_QUAD_EN_BIT7))

>                 return 0;
> 
>         /* Update the Quad Enable bit. */
> -       *sr2 |= SR2_QUAD_EN_BIT7;
> +       if (enable)
> +               *sr2 |= SR2_QUAD_EN_BIT7;
> +       else
> +               *sr2 &= ~SR2_QUAD_EN_BIT7;
> 
>         ret = spi_nor_write_sr2(nor, sr2);
>         if (ret)
> @@ -2898,12 +2916,13 @@ static int spi_nor_init_params(struct spi_nor *nor)
>  }
> 
>  /**
> - * spi_nor_quad_enable() - enable Quad I/O if needed.
> + * spi_nor_quad_enable() - enable/disable Quad I/O if needed.
>   * @nor:                pointer to a 'struct spi_nor'
> + * @enable:             true to enable quad mode. false to disable.

ditto

>   *
>   * Return: 0 on success, -errno otherwise.
>   */
> -static int spi_nor_quad_enable(struct spi_nor *nor)
> +static int spi_nor_quad_enable(struct spi_nor *nor, bool enable)
>  {
>         if (!nor->params->quad_enable)
>                 return 0;
> @@ -2912,7 +2931,7 @@ static int spi_nor_quad_enable(struct spi_nor *nor)
>               spi_nor_get_protocol_width(nor->write_proto) == 4))
>                 return 0;
> 
> -       return nor->params->quad_enable(nor);
> +       return nor->params->quad_enable(nor, enable);
>  }
> 
>  /**
> @@ -2936,7 +2955,7 @@ static int spi_nor_init(struct spi_nor *nor)
>  {
>         int err;
> 
> -       err = spi_nor_quad_enable(nor);
> +       err = spi_nor_quad_enable(nor, true);
>         if (err) {
>                 dev_dbg(nor->dev, "quad mode not supported\n");
>                 return err;
> diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
> index 6f2f6b2..222e0d3 100644
> --- a/drivers/mtd/spi-nor/core.h
> +++ b/drivers/mtd/spi-nor/core.h
> @@ -198,7 +198,7 @@ struct spi_nor_locking_ops {
>   *                      higher index in the array, the higher priority.
>   * @erase_map:         the erase map parsed from the SFDP Sector Map Parameter
>   *                      Table.
> - * @quad_enable:       enables SPI NOR quad mode.
> + * @quad_enable:       enables/disables SPI NOR quad mode.
>   * @set_4byte_addr_mode: puts the SPI NOR in 4 byte addressing mode.
>   * @convert_addr:      converts an absolute address into something the flash
>   *                      will understand. Particularly useful when pagesize is
> @@ -219,7 +219,7 @@ struct spi_nor_flash_parameter {
> 
>         struct spi_nor_erase_map        erase_map;
> 
> -       int (*quad_enable)(struct spi_nor *nor);
> +       int (*quad_enable)(struct spi_nor *nor, bool enable);
>         int (*set_4byte_addr_mode)(struct spi_nor *nor, bool enable);
>         u32 (*convert_addr)(struct spi_nor *nor, u32 addr);
>         int (*setup)(struct spi_nor *nor, const struct spi_nor_hwcaps *hwcaps);
> @@ -406,9 +406,9 @@ int spi_nor_write_ear(struct spi_nor *nor, u8 ear);
>  int spi_nor_wait_till_ready(struct spi_nor *nor);
>  int spi_nor_lock_and_prep(struct spi_nor *nor);
>  void spi_nor_unlock_and_unprep(struct spi_nor *nor);
> -int spi_nor_sr1_bit6_quad_enable(struct spi_nor *nor);
> -int spi_nor_sr2_bit1_quad_enable(struct spi_nor *nor);
> -int spi_nor_sr2_bit7_quad_enable(struct spi_nor *nor);
> +int spi_nor_sr1_bit6_quad_enable(struct spi_nor *nor, bool enable);
> +int spi_nor_sr2_bit1_quad_enable(struct spi_nor *nor, bool enable);
> +int spi_nor_sr2_bit7_quad_enable(struct spi_nor *nor, bool enable);
> 
>  int spi_nor_xread_sr(struct spi_nor *nor, u8 *sr);
>  ssize_t spi_nor_read_data(struct spi_nor *nor, loff_t from, size_t len,
> --
> 2.8.1
> 

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  reply	other threads:[~2020-07-02 11:08 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-16 13:02 [PATCH 0/2] Add support to Disable the flash quad mode Yicong Yang
2020-06-16 13:02 ` [PATCH 1/2] mtd: spi-nor: Add capability to disable " Yicong Yang
2020-07-02 11:07   ` Tudor.Ambarus [this message]
2020-06-16 13:02 ` [PATCH 2/2] mtd: spi-nor: Disable the flash quad mode in spi_nor_restore() Yicong Yang
2020-07-02 11:02   ` Tudor.Ambarus
2020-07-03 11:19     ` Pratyush Yadav
2020-07-03 11:52       ` Tudor.Ambarus
2020-07-06  6:47         ` Yicong Yang
2020-09-01  6:16   ` Matthias Weißer
2020-09-01  9:48     ` Pratyush Yadav
2020-09-01 10:08       ` Matthias Weißer
2020-09-01 11:11         ` Pratyush Yadav
2020-09-01 11:41     ` Yicong Yang
2020-09-01 14:20     ` Yicong Yang
2020-09-02  7:50       ` Vignesh Raghavendra
2020-09-02 10:12         ` Yicong Yang
2020-09-03  5:59           ` Vignesh Raghavendra
2020-09-04  7:54             ` Yicong Yang
2020-09-04  9:35               ` Matthias Weißer
2020-09-02 12:15       ` Matthias Weißer
2020-09-03  3:03         ` Yicong Yang
2020-09-03  5:33           ` Matthias Weißer
2020-09-04  7:56             ` Yicong Yang

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