On Fri, Dec 05, 2014 at 07:09:59AM +0000, Bean Huo 霍斌斌 (beanhuo) wrote:
> This patch adds code which enables Quad I/O mode on Micron SPI NOR flashes.
>
> For Micron SPI NOR flash,enabling or disabling quad I/O protocol can be done
> By two methods, which are to use EVCR(Enhanced Volatile Configuration
> Register)
> and the ENTER QUAD I/O MODE command.There is no difference between these two
> methods.Unfortunately,for some Micron spi nor flashes,there no ENTER Quad I/O
> command(35h),such as n25q064.But for all current Micron spi nor,if it support
> quad I/O mode,using EVCR definitely be supported.It is a recommended method to
> enable Quad I/O mode by EVCR,Quad I/O protocol bit 7.When EVCR bit 7 is reset
> to 0,the SPI NOR flash will operate in quad I/O mode.
>
> This patch has been tested on N25Q512A and MT25TL256BAA1ESF.Micron spi nor of
> spi_nor_ids[] table all support this method.
>
> Signed-off-by: bean huo <[email protected]>
> Acked-by: Marek Vasut <[email protected]>
> ---
> v1-v2:
> Modified to that capture wait_till_ready()
> return value,if error,directly return its
> the value.
> v2-v3:
> Directly use the reurning error value of
> read_reg and write_reg,instead of -EINVAL.
> v3-v4:
> Modify commit logs that wraped into 80 columns.
> v4-v5:
> Rebuild new patch based on latest linux-mtd.
> v5-v6:
> Rebuild patch based on latest l2-mtd.
> add some comments.
> Add SPI_NOR_QUAD_READ flag in the spi_nor_ids[] for Micron spi nor.
>
> drivers/mtd/spi-nor/spi-nor.c | 61
> +++++++++++++++++++++++++++++++++++------
> include/linux/mtd/spi-nor.h | 7 +++++
> 2 files changed, 60 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index 0f8ec3c..128941e 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -560,14 +560,14 @@ static const struct spi_device_id spi_nor_ids[] = {
> { "mx66l1g55g", INFO(0xc2261b, 0, 64 * 1024, 2048, SPI_NOR_QUAD_READ)
> },
>
> /* Micron */
> - { "n25q032", INFO(0x20ba16, 0, 64 * 1024, 64, 0) },
> - { "n25q064", INFO(0x20ba17, 0, 64 * 1024, 128, 0) },
> - { "n25q128a11", INFO(0x20bb18, 0, 64 * 1024, 256, 0) },
> - { "n25q128a13", INFO(0x20ba18, 0, 64 * 1024, 256, 0) },
> - { "n25q256a", INFO(0x20ba19, 0, 64 * 1024, 512, SECT_4K) },
> - { "n25q512a", INFO(0x20bb20, 0, 64 * 1024, 1024, SECT_4K) },
> - { "n25q512ax3", INFO(0x20ba20, 0, 64 * 1024, 1024, USE_FSR) },
> - { "n25q00", INFO(0x20ba21, 0, 64 * 1024, 2048, USE_FSR) },
> + { "n25q032", INFO(0x20ba16, 0, 64 * 1024, 64, SPI_NOR_QUAD_READ)
> },
> + { "n25q064", INFO(0x20ba17, 0, 64 * 1024, 128, SPI_NOR_QUAD_READ)
> },
> + { "n25q128a11", INFO(0x20bb18, 0, 64 * 1024, 256, SPI_NOR_QUAD_READ)
> },
> + { "n25q128a13", INFO(0x20ba18, 0, 64 * 1024, 256, SPI_NOR_QUAD_READ)
> },
> + { "n25q256a", INFO(0x20ba19, 0, 64 * 1024, 512, SECT_4K |
> SPI_NOR_QUAD_READ) },
> + { "n25q512a", INFO(0x20bb20, 0, 64 * 1024, 1024, SECT_4K | USE_FSR |
> SPI_NOR_QUAD_READ) },
> + { "n25q512ax3", INFO(0x20ba20, 0, 64 * 1024, 1024, SECT_4K | USE_FSR |
> SPI_NOR_QUAD_READ) },
> + { "n25q00", INFO(0x20ba21, 0, 64 * 1024, 2048, SECT_4K | USE_FSR |
> SPI_NOR_QUAD_READ) },
Are you sure *all* of these support quad mode? I know some manufacturers
have been known to reuse IDs, and I wouldn't want a false positive to
slip in here, where an old part might not support it but the new one
does...
>
> /* PMC */
> { "pm25lv512", INFO(0, 0, 32 * 1024, 2, SECT_4K_PMC) },
> @@ -891,6 +891,44 @@ static int spansion_quad_enable(struct spi_nor *nor)
> return 0;
> }
>
> +static int micron_quad_enable(struct spi_nor *nor)
> +{
> + int ret, val;
> +
> + ret = nor->read_reg(nor, SPINOR_OP_RD_EVCR, &val, 1);
sparse (rightfully) complains about this line:
drivers/mtd/spi-nor/spi-nor.c: In function ‘micron_quad_enable’:
drivers/mtd/spi-nor/spi-nor.c:898:2: warning: passing argument 3 of
‘nor->read_reg’ from incompatible pointer type [enabled by default]
ret = nor->read_reg(nor, SPINOR_OP_RD_EVCR, &val, 1);
^
drivers/mtd/spi-nor/spi-nor.c:898:2: note: expected ‘u8 *’ but argument is of
type ‘int *’
drivers/mtd/spi-nor/spi-nor.c:898:54: warning: incorrect type in argument 3
(different type sizes) [sparse]
drivers/mtd/spi-nor/spi-nor.c:898:54: expected unsigned char [usertype] *buf
[sparse]
drivers/mtd/spi-nor/spi-nor.c:898:54: got int *<noident> [sparse]
So 'val' should be of type u8. Otherwise, you risk utilizing
uninitialized data for the other 32-8 bits.
> + if (ret < 0) {
> + dev_err(nor->dev, "error %d reading EVCR\n", ret);
> + return ret;
> + }
> +
> + write_enable(nor);
> +
> + /* set EVCR ,enable quad I/O */
You have the space on the wrong side of the comma.
> + nor->cmd_buf[0] = val & ~EVCR_QUAD_EN_MICRON;
> + ret = nor->write_reg(nor, SPINOR_OP_WD_EVCR, nor->cmd_buf, 1, 0);
> + if (ret < 0) {
> + dev_err(nor->dev, "error while writing EVCR register\n");
> + return ret;
> + }
> +
> + ret = spi_nor_wait_till_ready(nor);
> + if (ret)
> + return ret;
> +
> + /* read EVCR and check it */
> + ret = nor->read_reg(nor, SPINOR_OP_RD_EVCR, &val, 1);
Same here:
drivers/mtd/spi-nor/spi-nor.c:919:2: warning: passing argument 3 of
‘nor->read_reg’ from incompatible pointer type [enabled by default]
ret = nor->read_reg(nor, SPINOR_OP_RD_EVCR, &val, 1);
^
drivers/mtd/spi-nor/spi-nor.c:919:2: note: expected ‘u8 *’ but argument is of
type ‘int *’
drivers/mtd/spi-nor/spi-nor.c:919:54: warning: incorrect type in argument 3
(different type sizes) [sparse]
drivers/mtd/spi-nor/spi-nor.c:919:54: expected unsigned char [usertype] *buf
[sparse]
drivers/mtd/spi-nor/spi-nor.c:919:54: got int *<noident> [sparse]
> + if (ret < 0) {
> + dev_err(nor->dev, "error %d reading EVCR\n", ret);
> + return ret;
> + }
> + if (val & EVCR_QUAD_EN_MICRON) {
> + dev_err(nor->dev, "Micron EVCR Quad bit not clear\n");
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> static int set_quad_mode(struct spi_nor *nor, struct flash_info *info)
> {
> int status;
> @@ -903,6 +941,13 @@ static int set_quad_mode(struct spi_nor *nor, struct
> flash_info *info)
> return -EINVAL;
> }
> return status;
> + case CFI_MFR_ST:
> + status = micron_quad_enable(nor);
> + if (status) {
> + dev_err(nor->dev, "Micron quad-read not enabled\n");
> + return -EINVAL;
> + }
> + return status;
> default:
> status = spansion_quad_enable(nor);
> if (status) {
> diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
> index 63aeccf..4720b86 100644
> --- a/include/linux/mtd/spi-nor.h
> +++ b/include/linux/mtd/spi-nor.h
> @@ -56,6 +56,10 @@
> /* Used for Spansion flashes only. */
> #define SPINOR_OP_BRWR 0x17 /* Bank register write */
>
> +/* Used for Micron flashes only. */
> +#define SPINOR_OP_RD_EVCR 0x65 /* Read EVCR register */
> +#define SPINOR_OP_WD_EVCR 0x61 /* Write EVCR register */
> +
> /* Status Register bits. */
> #define SR_WIP 1 /* Write in progress */
> #define SR_WEL 2 /* Write enable latch */
> @@ -67,6 +71,9 @@
>
> #define SR_QUAD_EN_MX 0x40 /* Macronix Quad I/O */
>
> +/* Enhanced Volatile Configuration Register bits */
> +#define EVCR_QUAD_EN_MICRON 0x80 /* Micron Quad I/O */
> +
> /* Flag Status Register bits */
> #define FSR_READY 0x80
>
With int vs. u8 fixed up, this looks good. Hopefully I can take v7!
Thanks,
Brian
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