Re: [PATCH v4 08/20] mtd: spi-nor: Describe all the Reg Ops

[Vignesh Raghavendra]

On 02/11/19 4:53 PM, Tudor.Ambarus@xxxxxxxxxxxxx wrote:
> From: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
> 
> Document all the Register Operations.
> 
> Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>

Reviewed-by: Vignesh Raghavendra <vigneshr@xxxxxx>

Regards
Vignesh

> ---
>  drivers/mtd/spi-nor/spi-nor.c | 138 ++++++++++++++++++++++++++++++++++++++----
>  1 file changed, 127 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index 857675a4e329..99a9a6aba41d 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -388,9 +388,11 @@ static ssize_t spi_nor_write_data(struct spi_nor *nor, loff_t to, size_t len,
>  	return nor->controller_ops->write(nor, to, len, buf);
>  }
>  
> -/*
> - * Set write enable latch with Write Enable command.
> - * Returns negative if error occurred.
> +/**
> + * spi_nor_write_enable() - Set write enable latch with Write Enable command.
> + * @nor:	pointer to 'struct spi_nor'.
> + *
> + * Return: 0 on success, -errno otherwise.
>   */
>  static int spi_nor_write_enable(struct spi_nor *nor)
>  {
> @@ -415,8 +417,11 @@ static int spi_nor_write_enable(struct spi_nor *nor)
>  	return ret;
>  }
>  
> -/*
> - * Send write disable instruction to the chip.
> +/**
> + * spi_nor_write_disable() - Send Write Disable instruction to the chip.
> + * @nor:	pointer to 'struct spi_nor'.
> + *
> + * Return: 0 on success, -errno otherwise.
>   */
>  static int spi_nor_write_disable(struct spi_nor *nor)
>  {
> @@ -534,6 +539,14 @@ static int spi_nor_read_cr(struct spi_nor *nor, u8 *cr)
>  	return ret;
>  }
>  
> +/**
> + * macronix_set_4byte() - Set 4-byte address mode for Macronix flashes.
> + * @nor:	pointer to 'struct spi_nor'.
> + * @enable:	true to enter the 4-byte address mode, false to exit the 4-byte
> + *		address mode.
> + *
> + * Return: 0 on success, -errno otherwise.
> + */
>  static int macronix_set_4byte(struct spi_nor *nor, bool enable)
>  {
>  	int ret;
> @@ -562,6 +575,14 @@ static int macronix_set_4byte(struct spi_nor *nor, bool enable)
>  	return ret;
>  }
>  
> +/**
> + * st_micron_set_4byte() - Set 4-byte address mode for ST and Micron flashes.
> + * @nor:	pointer to 'struct spi_nor'.
> + * @enable:	true to enter the 4-byte address mode, false to exit the 4-byte
> + *		address mode.
> + *
> + * Return: 0 on success, -errno otherwise.
> + */
>  static int st_micron_set_4byte(struct spi_nor *nor, bool enable)
>  {
>  	int ret;
> @@ -577,6 +598,14 @@ static int st_micron_set_4byte(struct spi_nor *nor, bool enable)
>  	return spi_nor_write_disable(nor);
>  }
>  
> +/**
> + * spansion_set_4byte() - Set 4-byte address mode for Spansion flashes.
> + * @nor:	pointer to 'struct spi_nor'.
> + * @enable:	true to enter the 4-byte address mode, false to exit the 4-byte
> + *		address mode.
> + *
> + * Return: 0 on success, -errno otherwise.
> + */
>  static int spansion_set_4byte(struct spi_nor *nor, bool enable)
>  {
>  	int ret;
> @@ -602,6 +631,13 @@ static int spansion_set_4byte(struct spi_nor *nor, bool enable)
>  	return ret;
>  }
>  
> +/**
> + * spi_nor_write_ear() - Write Extended Address Register.
> + * @nor:	pointer to 'struct spi_nor'.
> + * @ear:	value to write to the Extended Address Register.
> + *
> + * Return: 0 on success, -errno otherwise.
> + */
>  static int spi_nor_write_ear(struct spi_nor *nor, u8 ear)
>  {
>  	int ret;
> @@ -627,6 +663,14 @@ static int spi_nor_write_ear(struct spi_nor *nor, u8 ear)
>  	return ret;
>  }
>  
> +/**
> + * winbond_set_4byte() - Set 4-byte address mode for Winbond flashes.
> + * @nor:	pointer to 'struct spi_nor'.
> + * @enable:	true to enter the 4-byte address mode, false to exit the 4-byte
> + *		address mode.
> + *
> + * Return: 0 on success, -errno otherwise.
> + */
>  static int winbond_set_4byte(struct spi_nor *nor, bool enable)
>  {
>  	int ret;
> @@ -651,6 +695,14 @@ static int winbond_set_4byte(struct spi_nor *nor, bool enable)
>  	return spi_nor_write_disable(nor);
>  }
>  
> +/**
> + * spi_nor_xread_sr() - Read the Status Register on S3AN flashes.
> + * @nor:	pointer to 'struct spi_nor'.
> + * @sr:		pointer to a DMA-able buffer where the value of the
> + *              Status Register will be written.
> + *
> + * Return: 0 on success, -errno otherwise.
> + */
>  static int spi_nor_xread_sr(struct spi_nor *nor, u8 *sr)
>  {
>  	int ret;
> @@ -674,6 +726,13 @@ static int spi_nor_xread_sr(struct spi_nor *nor, u8 *sr)
>  	return ret;
>  }
>  
> +/**
> + * s3an_sr_ready() - Query the Status Register of the S3AN flash to see if the
> + * flash is ready for new commands.
> + * @nor:	pointer to 'struct spi_nor'.
> + *
> + * Return: 0 on success, -errno otherwise.
> + */
>  static int s3an_sr_ready(struct spi_nor *nor)
>  {
>  	int ret;
> @@ -685,6 +744,10 @@ static int s3an_sr_ready(struct spi_nor *nor)
>  	return !!(nor->bouncebuf[0] & XSR_RDY);
>  }
>  
> +/**
> + * spi_nor_clear_sr() - Clear the Status Register.
> + * @nor:	pointer to 'struct spi_nor'.
> + */
>  static void spi_nor_clear_sr(struct spi_nor *nor)
>  {
>  	int ret;
> @@ -706,6 +769,13 @@ static void spi_nor_clear_sr(struct spi_nor *nor)
>  		dev_dbg(nor->dev, "error %d clearing SR\n", ret);
>  }
>  
> +/**
> + * spi_nor_sr_ready() - Query the Status Register to see if the flash is ready
> + * for new commands.
> + * @nor:	pointer to 'struct spi_nor'.
> + *
> + * Return: 0 on success, -errno otherwise.
> + */
>  static int spi_nor_sr_ready(struct spi_nor *nor)
>  {
>  	int ret = spi_nor_read_sr(nor, nor->bouncebuf);
> @@ -727,6 +797,10 @@ static int spi_nor_sr_ready(struct spi_nor *nor)
>  	return !(nor->bouncebuf[0] & SR_WIP);
>  }
>  
> +/**
> + * spi_nor_clear_fsr() - Clear the Flag Status Register.
> + * @nor:	pointer to 'struct spi_nor'.
> + */
>  static void spi_nor_clear_fsr(struct spi_nor *nor)
>  {
>  	int ret;
> @@ -748,6 +822,13 @@ static void spi_nor_clear_fsr(struct spi_nor *nor)
>  		dev_dbg(nor->dev, "error %d clearing FSR\n", ret);
>  }
>  
> +/**
> + * spi_nor_fsr_ready() - Query the Flag Status Register to see if the flash is
> + * ready for new commands.
> + * @nor:	pointer to 'struct spi_nor'.
> + *
> + * Return: 0 on success, -errno otherwise.
> + */
>  static int spi_nor_fsr_ready(struct spi_nor *nor)
>  {
>  	int ret = spi_nor_read_fsr(nor, nor->bouncebuf);
> @@ -772,6 +853,12 @@ static int spi_nor_fsr_ready(struct spi_nor *nor)
>  	return nor->bouncebuf[0] & FSR_READY;
>  }
>  
> +/**
> + * spi_nor_ready() - Query the flash to see if it is ready for new commands.
> + * @nor:	pointer to 'struct spi_nor'.
> + *
> + * Return: 0 on success, -errno otherwise.
> + */
>  static int spi_nor_ready(struct spi_nor *nor)
>  {
>  	int sr, fsr;
> @@ -788,9 +875,13 @@ static int spi_nor_ready(struct spi_nor *nor)
>  	return sr && fsr;
>  }
>  
> -/*
> - * Service routine to read status register until ready, or timeout occurs.
> - * Returns non-zero if error.
> +/**
> + * spi_nor_wait_till_ready_with_timeout() - Service routine to read the
> + * Status Register until ready, or timeout occurs.
> + * @nor:		pointer to "struct spi_nor".
> + * @timeout_jiffies:	jiffies to wait until timeout.
> + *
> + * Return: 0 on success, -errno otherwise.
>   */
>  static int spi_nor_wait_till_ready_with_timeout(struct spi_nor *nor,
>  						unsigned long timeout_jiffies)
> @@ -818,6 +909,13 @@ static int spi_nor_wait_till_ready_with_timeout(struct spi_nor *nor,
>  	return -ETIMEDOUT;
>  }
>  
> +/**
> + * spi_nor_wait_till_ready() - Wait for a predefined amount of time for the
> + * flash to be ready, or timeout occurs.
> + * @nor:	pointer to "struct spi_nor".
> + *
> + * Return: 0 on success, -errno otherwise.
> + */
>  static int spi_nor_wait_till_ready(struct spi_nor *nor)
>  {
>  	return spi_nor_wait_till_ready_with_timeout(nor,
> @@ -880,6 +978,14 @@ static int spi_nor_write_sr_and_check(struct spi_nor *nor, u8 status_new,
>  	return ((nor->bouncebuf[0] & mask) != (status_new & mask)) ? -EIO : 0;
>  }
>  
> +/**
> + * spi_nor_write_sr2() - Write the Status Register 2 using the
> + * SPINOR_OP_WRSR2 (3eh) command.
> + * @nor:	pointer to 'struct spi_nor'.
> + * @sr2:	pointer to DMA-able buffer to write to the Status Register 2.
> + *
> + * Return: 0 on success, -errno otherwise.
> + */
>  static int spi_nor_write_sr2(struct spi_nor *nor, const u8 *sr2)
>  {
>  	int ret;
> @@ -909,6 +1015,15 @@ static int spi_nor_write_sr2(struct spi_nor *nor, const u8 *sr2)
>  	return spi_nor_wait_till_ready(nor);
>  }
>  
> +/**
> + * spi_nor_read_sr2() - Read the Status Register 2 using the
> + * SPINOR_OP_RDSR2 (3fh) command.
> + * @nor:	pointer to 'struct spi_nor'.
> + * @sr2:	pointer to DMA-able buffer where the value of the
> + *		Status Register 2 will be written.
> + *
> + * Return: 0 on success, -errno otherwise.
> + */
>  static int spi_nor_read_sr2(struct spi_nor *nor, u8 *sr2)
>  {
>  	int ret;
> @@ -932,10 +1047,11 @@ static int spi_nor_read_sr2(struct spi_nor *nor, u8 *sr2)
>  	return ret;
>  }
>  
> -/*
> - * Erase the whole flash memory
> +/**
> + * spi_nor_erase_chip() - Erase the entire flash memory.
> + * @nor:	pointer to 'struct spi_nor'.
>   *
> - * Returns 0 if successful, non-zero otherwise.
> + * Return: 0 on success, -errno otherwise.
>   */
>  static int spi_nor_erase_chip(struct spi_nor *nor)
>  {
> 

-- 
Regards
Vignesh