Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Sun, 25 Aug 2019 14:34:16 +0200
From:   Boris Brezillon <boris.brezillon@collabora.com>
To:     <Tudor.Ambarus@microchip.com>
Cc:     <marek.vasut@gmail.com>, <vigneshr@ti.com>,
        <miquel.raynal@bootlin.com>, <richard@nod.at>,
        <linux-mtd@lists.infradead.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 4/6] mtd: spi_nor: Add a ->setup() method
Message-ID: <20190825143416.33932df0@collabora.com>
In-Reply-To: <20190824120650.14752-5-tudor.ambarus@microchip.com>
References: <20190824120650.14752-1-tudor.ambarus@microchip.com>
        <20190824120650.14752-5-tudor.ambarus@microchip.com>
Organization: Collabora
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Sat, 24 Aug 2019 12:07:14 +0000
<Tudor.Ambarus@microchip.com> wrote:

> From: Tudor Ambarus <tudor.ambarus@microchip.com>
> 
> nor->params.setup() configures the SPI NOR memory. Useful for SPI NOR
> flashes that have peculiarities to the SPI NOR standard, e.g.
> different opcodes, specific address calculation, page size, etc.
> Right now the only user will be the S3AN chips, but other
> manufacturers can implement it if needed.
> 
> Move spi_nor_setup() related code in order to avoid a forward
> declaration to spi_nor_default_setup().
> 
> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>

> ---
>  drivers/mtd/spi-nor/spi-nor.c | 428 +++++++++++++++++++++---------------------
>  include/linux/mtd/spi-nor.h   |   5 +
>  2 files changed, 224 insertions(+), 209 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index 0dc6a683719e..17e6c96f9f9a 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -4144,6 +4144,224 @@ static int spi_nor_parse_sfdp(struct spi_nor *nor,
>  	return err;
>  }
>  
> +static int spi_nor_select_read(struct spi_nor *nor,
> +			       u32 shared_hwcaps)
> +{
> +	int cmd, best_match = fls(shared_hwcaps & SNOR_HWCAPS_READ_MASK) - 1;
> +	const struct spi_nor_read_command *read;
> +
> +	if (best_match < 0)
> +		return -EINVAL;
> +
> +	cmd = spi_nor_hwcaps_read2cmd(BIT(best_match));
> +	if (cmd < 0)
> +		return -EINVAL;
> +
> +	read = &nor->params.reads[cmd];
> +	nor->read_opcode = read->opcode;
> +	nor->read_proto = read->proto;
> +
> +	/*
> +	 * In the spi-nor framework, we don't need to make the difference
> +	 * between mode clock cycles and wait state clock cycles.
> +	 * Indeed, the value of the mode clock cycles is used by a QSPI
> +	 * flash memory to know whether it should enter or leave its 0-4-4
> +	 * (Continuous Read / XIP) mode.
> +	 * eXecution In Place is out of the scope of the mtd sub-system.
> +	 * Hence we choose to merge both mode and wait state clock cycles
> +	 * into the so called dummy clock cycles.
> +	 */
> +	nor->read_dummy = read->num_mode_clocks + read->num_wait_states;
> +	return 0;
> +}
> +
> +static int spi_nor_select_pp(struct spi_nor *nor,
> +			     u32 shared_hwcaps)
> +{
> +	int cmd, best_match = fls(shared_hwcaps & SNOR_HWCAPS_PP_MASK) - 1;
> +	const struct spi_nor_pp_command *pp;
> +
> +	if (best_match < 0)
> +		return -EINVAL;
> +
> +	cmd = spi_nor_hwcaps_pp2cmd(BIT(best_match));
> +	if (cmd < 0)
> +		return -EINVAL;
> +
> +	pp = &nor->params.page_programs[cmd];
> +	nor->program_opcode = pp->opcode;
> +	nor->write_proto = pp->proto;
> +	return 0;
> +}
> +
> +/**
> + * spi_nor_select_uniform_erase() - select optimum uniform erase type
> + * @map:		the erase map of the SPI NOR
> + * @wanted_size:	the erase type size to search for. Contains the value of
> + *			info->sector_size or of the "small sector" size in case
> + *			CONFIG_MTD_SPI_NOR_USE_4K_SECTORS is defined.
> + *
> + * Once the optimum uniform sector erase command is found, disable all the
> + * other.
> + *
> + * Return: pointer to erase type on success, NULL otherwise.
> + */
> +static const struct spi_nor_erase_type *
> +spi_nor_select_uniform_erase(struct spi_nor_erase_map *map,
> +			     const u32 wanted_size)
> +{
> +	const struct spi_nor_erase_type *tested_erase, *erase = NULL;
> +	int i;
> +	u8 uniform_erase_type = map->uniform_erase_type;
> +
> +	for (i = SNOR_ERASE_TYPE_MAX - 1; i >= 0; i--) {
> +		if (!(uniform_erase_type & BIT(i)))
> +			continue;
> +
> +		tested_erase = &map->erase_type[i];
> +
> +		/*
> +		 * If the current erase size is the one, stop here:
> +		 * we have found the right uniform Sector Erase command.
> +		 */
> +		if (tested_erase->size == wanted_size) {
> +			erase = tested_erase;
> +			break;
> +		}
> +
> +		/*
> +		 * Otherwise, the current erase size is still a valid canditate.
> +		 * Select the biggest valid candidate.
> +		 */
> +		if (!erase && tested_erase->size)
> +			erase = tested_erase;
> +			/* keep iterating to find the wanted_size */
> +	}
> +
> +	if (!erase)
> +		return NULL;
> +
> +	/* Disable all other Sector Erase commands. */
> +	map->uniform_erase_type &= ~SNOR_ERASE_TYPE_MASK;
> +	map->uniform_erase_type |= BIT(erase - map->erase_type);
> +	return erase;
> +}
> +
> +static int spi_nor_select_erase(struct spi_nor *nor, u32 wanted_size)
> +{
> +	struct spi_nor_erase_map *map = &nor->params.erase_map;
> +	const struct spi_nor_erase_type *erase = NULL;
> +	struct mtd_info *mtd = &nor->mtd;
> +	int i;
> +
> +	/*
> +	 * The previous implementation handling Sector Erase commands assumed
> +	 * that the SPI flash memory has an uniform layout then used only one
> +	 * of the supported erase sizes for all Sector Erase commands.
> +	 * So to be backward compatible, the new implementation also tries to
> +	 * manage the SPI flash memory as uniform with a single erase sector
> +	 * size, when possible.
> +	 */
> +#ifdef CONFIG_MTD_SPI_NOR_USE_4K_SECTORS
> +	/* prefer "small sector" erase if possible */
> +	wanted_size = 4096u;
> +#endif
> +
> +	if (spi_nor_has_uniform_erase(nor)) {
> +		erase = spi_nor_select_uniform_erase(map, wanted_size);
> +		if (!erase)
> +			return -EINVAL;
> +		nor->erase_opcode = erase->opcode;
> +		mtd->erasesize = erase->size;
> +		return 0;
> +	}
> +
> +	/*
> +	 * For non-uniform SPI flash memory, set mtd->erasesize to the
> +	 * maximum erase sector size. No need to set nor->erase_opcode.
> +	 */
> +	for (i = SNOR_ERASE_TYPE_MAX - 1; i >= 0; i--) {
> +		if (map->erase_type[i].size) {
> +			erase = &map->erase_type[i];
> +			break;
> +		}
> +	}
> +
> +	if (!erase)
> +		return -EINVAL;
> +
> +	mtd->erasesize = erase->size;
> +	return 0;
> +}
> +
> +static int spi_nor_default_setup(struct spi_nor *nor,
> +				 const struct spi_nor_hwcaps *hwcaps)
> +{
> +	struct spi_nor_flash_parameter *params = &nor->params;
> +	u32 ignored_mask, shared_mask;
> +	int err;
> +
> +	/*
> +	 * Keep only the hardware capabilities supported by both the SPI
> +	 * controller and the SPI flash memory.
> +	 */
> +	shared_mask = hwcaps->mask & params->hwcaps.mask;
> +
> +	if (nor->spimem) {
> +		/*
> +		 * When called from spi_nor_probe(), all caps are set and we
> +		 * need to discard some of them based on what the SPI
> +		 * controller actually supports (using spi_mem_supports_op()).
> +		 */
> +		spi_nor_spimem_adjust_hwcaps(nor, &shared_mask);
> +	} else {
> +		/*
> +		 * SPI n-n-n protocols are not supported when the SPI
> +		 * controller directly implements the spi_nor interface.
> +		 * Yet another reason to switch to spi-mem.
> +		 */
> +		ignored_mask = SNOR_HWCAPS_X_X_X;
> +		if (shared_mask & ignored_mask) {
> +			dev_dbg(nor->dev,
> +				"SPI n-n-n protocols are not supported.\n");
> +			shared_mask &= ~ignored_mask;
> +		}
> +	}
> +
> +	/* Select the (Fast) Read command. */
> +	err = spi_nor_select_read(nor, shared_mask);
> +	if (err) {
> +		dev_err(nor->dev,
> +			"can't select read settings supported by both the SPI controller and memory.\n");
> +		return err;
> +	}
> +
> +	/* Select the Page Program command. */
> +	err = spi_nor_select_pp(nor, shared_mask);
> +	if (err) {
> +		dev_err(nor->dev,
> +			"can't select write settings supported by both the SPI controller and memory.\n");
> +		return err;
> +	}
> +
> +	/* Select the Sector Erase command. */
> +	err = spi_nor_select_erase(nor, nor->info->sector_size);
> +	if (err)
> +		dev_err(nor->dev,
> +			"can't select erase settings supported by both the SPI controller and memory.\n");
> +
> +	return err;
> +}
> +
> +static int spi_nor_setup(struct spi_nor *nor,
> +			 const struct spi_nor_hwcaps *hwcaps)
> +{
> +	if (!nor->params.setup)
> +		return 0;
> +
> +	return nor->params.setup(nor, hwcaps);
> +}
> +
>  static void atmel_set_default_init(struct spi_nor *nor)
>  {
>  	nor->params.disable_block_protection = spi_nor_clear_sr_bp;
> @@ -4247,6 +4465,7 @@ static void spi_nor_legacy_init_params(struct spi_nor *nor)
>  	/* Initialize legacy flash parameters and settings. */
>  	params->quad_enable = spansion_quad_enable;
>  	params->set_4byte = spansion_set_4byte;
> +	params->setup = spi_nor_default_setup;
>  
>  	/* Set SPI NOR sizes. */
>  	params->size = (u64)info->sector_size * info->n_sectors;
> @@ -4421,215 +4640,6 @@ static void spi_nor_init_params(struct spi_nor *nor)
>  	spi_nor_late_init_params(nor);
>  }
>  
> -static int spi_nor_select_read(struct spi_nor *nor,
> -			       u32 shared_hwcaps)
> -{
> -	int cmd, best_match = fls(shared_hwcaps & SNOR_HWCAPS_READ_MASK) - 1;
> -	const struct spi_nor_read_command *read;
> -
> -	if (best_match < 0)
> -		return -EINVAL;
> -
> -	cmd = spi_nor_hwcaps_read2cmd(BIT(best_match));
> -	if (cmd < 0)
> -		return -EINVAL;
> -
> -	read = &nor->params.reads[cmd];
> -	nor->read_opcode = read->opcode;
> -	nor->read_proto = read->proto;
> -
> -	/*
> -	 * In the spi-nor framework, we don't need to make the difference
> -	 * between mode clock cycles and wait state clock cycles.
> -	 * Indeed, the value of the mode clock cycles is used by a QSPI
> -	 * flash memory to know whether it should enter or leave its 0-4-4
> -	 * (Continuous Read / XIP) mode.
> -	 * eXecution In Place is out of the scope of the mtd sub-system.
> -	 * Hence we choose to merge both mode and wait state clock cycles
> -	 * into the so called dummy clock cycles.
> -	 */
> -	nor->read_dummy = read->num_mode_clocks + read->num_wait_states;
> -	return 0;
> -}
> -
> -static int spi_nor_select_pp(struct spi_nor *nor,
> -			     u32 shared_hwcaps)
> -{
> -	int cmd, best_match = fls(shared_hwcaps & SNOR_HWCAPS_PP_MASK) - 1;
> -	const struct spi_nor_pp_command *pp;
> -
> -	if (best_match < 0)
> -		return -EINVAL;
> -
> -	cmd = spi_nor_hwcaps_pp2cmd(BIT(best_match));
> -	if (cmd < 0)
> -		return -EINVAL;
> -
> -	pp = &nor->params.page_programs[cmd];
> -	nor->program_opcode = pp->opcode;
> -	nor->write_proto = pp->proto;
> -	return 0;
> -}
> -
> -/**
> - * spi_nor_select_uniform_erase() - select optimum uniform erase type
> - * @map:		the erase map of the SPI NOR
> - * @wanted_size:	the erase type size to search for. Contains the value of
> - *			info->sector_size or of the "small sector" size in case
> - *			CONFIG_MTD_SPI_NOR_USE_4K_SECTORS is defined.
> - *
> - * Once the optimum uniform sector erase command is found, disable all the
> - * other.
> - *
> - * Return: pointer to erase type on success, NULL otherwise.
> - */
> -static const struct spi_nor_erase_type *
> -spi_nor_select_uniform_erase(struct spi_nor_erase_map *map,
> -			     const u32 wanted_size)
> -{
> -	const struct spi_nor_erase_type *tested_erase, *erase = NULL;
> -	int i;
> -	u8 uniform_erase_type = map->uniform_erase_type;
> -
> -	for (i = SNOR_ERASE_TYPE_MAX - 1; i >= 0; i--) {
> -		if (!(uniform_erase_type & BIT(i)))
> -			continue;
> -
> -		tested_erase = &map->erase_type[i];
> -
> -		/*
> -		 * If the current erase size is the one, stop here:
> -		 * we have found the right uniform Sector Erase command.
> -		 */
> -		if (tested_erase->size == wanted_size) {
> -			erase = tested_erase;
> -			break;
> -		}
> -
> -		/*
> -		 * Otherwise, the current erase size is still a valid canditate.
> -		 * Select the biggest valid candidate.
> -		 */
> -		if (!erase && tested_erase->size)
> -			erase = tested_erase;
> -			/* keep iterating to find the wanted_size */
> -	}
> -
> -	if (!erase)
> -		return NULL;
> -
> -	/* Disable all other Sector Erase commands. */
> -	map->uniform_erase_type &= ~SNOR_ERASE_TYPE_MASK;
> -	map->uniform_erase_type |= BIT(erase - map->erase_type);
> -	return erase;
> -}
> -
> -static int spi_nor_select_erase(struct spi_nor *nor, u32 wanted_size)
> -{
> -	struct spi_nor_erase_map *map = &nor->params.erase_map;
> -	const struct spi_nor_erase_type *erase = NULL;
> -	struct mtd_info *mtd = &nor->mtd;
> -	int i;
> -
> -	/*
> -	 * The previous implementation handling Sector Erase commands assumed
> -	 * that the SPI flash memory has an uniform layout then used only one
> -	 * of the supported erase sizes for all Sector Erase commands.
> -	 * So to be backward compatible, the new implementation also tries to
> -	 * manage the SPI flash memory as uniform with a single erase sector
> -	 * size, when possible.
> -	 */
> -#ifdef CONFIG_MTD_SPI_NOR_USE_4K_SECTORS
> -	/* prefer "small sector" erase if possible */
> -	wanted_size = 4096u;
> -#endif
> -
> -	if (spi_nor_has_uniform_erase(nor)) {
> -		erase = spi_nor_select_uniform_erase(map, wanted_size);
> -		if (!erase)
> -			return -EINVAL;
> -		nor->erase_opcode = erase->opcode;
> -		mtd->erasesize = erase->size;
> -		return 0;
> -	}
> -
> -	/*
> -	 * For non-uniform SPI flash memory, set mtd->erasesize to the
> -	 * maximum erase sector size. No need to set nor->erase_opcode.
> -	 */
> -	for (i = SNOR_ERASE_TYPE_MAX - 1; i >= 0; i--) {
> -		if (map->erase_type[i].size) {
> -			erase = &map->erase_type[i];
> -			break;
> -		}
> -	}
> -
> -	if (!erase)
> -		return -EINVAL;
> -
> -	mtd->erasesize = erase->size;
> -	return 0;
> -}
> -
> -static int spi_nor_setup(struct spi_nor *nor,
> -			 const struct spi_nor_hwcaps *hwcaps)
> -{
> -	struct spi_nor_flash_parameter *params = &nor->params;
> -	u32 ignored_mask, shared_mask;
> -	int err;
> -
> -	/*
> -	 * Keep only the hardware capabilities supported by both the SPI
> -	 * controller and the SPI flash memory.
> -	 */
> -	shared_mask = hwcaps->mask & params->hwcaps.mask;
> -
> -	if (nor->spimem) {
> -		/*
> -		 * When called from spi_nor_probe(), all caps are set and we
> -		 * need to discard some of them based on what the SPI
> -		 * controller actually supports (using spi_mem_supports_op()).
> -		 */
> -		spi_nor_spimem_adjust_hwcaps(nor, &shared_mask);
> -	} else {
> -		/*
> -		 * SPI n-n-n protocols are not supported when the SPI
> -		 * controller directly implements the spi_nor interface.
> -		 * Yet another reason to switch to spi-mem.
> -		 */
> -		ignored_mask = SNOR_HWCAPS_X_X_X;
> -		if (shared_mask & ignored_mask) {
> -			dev_dbg(nor->dev,
> -				"SPI n-n-n protocols are not supported.\n");
> -			shared_mask &= ~ignored_mask;
> -		}
> -	}
> -
> -	/* Select the (Fast) Read command. */
> -	err = spi_nor_select_read(nor, shared_mask);
> -	if (err) {
> -		dev_err(nor->dev,
> -			"can't select read settings supported by both the SPI controller and memory.\n");
> -		return err;
> -	}
> -
> -	/* Select the Page Program command. */
> -	err = spi_nor_select_pp(nor, shared_mask);
> -	if (err) {
> -		dev_err(nor->dev,
> -			"can't select write settings supported by both the SPI controller and memory.\n");
> -		return err;
> -	}
> -
> -	/* Select the Sector Erase command. */
> -	err = spi_nor_select_erase(nor, nor->info->sector_size);
> -	if (err)
> -		dev_err(nor->dev,
> -			"can't select erase settings supported by both the SPI controller and memory.\n");
> -
> -	return err;
> -}
> -
>  /**
>   * spi_nor_quad_enable() - enable Quad I/O if needed.
>   * @nor:                pointer to a 'struct spi_nor'
> diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
> index f9f1947f7aeb..4752d08e9a3e 100644
> --- a/include/linux/mtd/spi-nor.h
> +++ b/include/linux/mtd/spi-nor.h
> @@ -498,6 +498,10 @@ struct spi_nor_locking_ops {
>   * @convert_addr:	converts an absolute address into something the flash
>   *                      will understand. Particularly useful when pagesize is
>   *                      not a power-of-2.
> + * @setup:		configures the SPI NOR memory. Useful for SPI NOR
> + *                      flashes that have peculiarities to the SPI NOR standard,
> + *                      e.g. different opcodes, specific address calculation,
> + *                      page size, etc.
>   * @disable_block_protection: disables block protection during power-up.
>   * @locking_ops:	SPI NOR locking methods.
>   */
> @@ -514,6 +518,7 @@ struct spi_nor_flash_parameter {
>  	int (*quad_enable)(struct spi_nor *nor);
>  	int (*set_4byte)(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);
>  	int (*disable_block_protection)(struct spi_nor *nor);
>  
>  	const struct spi_nor_locking_ops *locking_ops;