RE: [EXT] [PATCH] spi: spi-fsl-qspi: Clear TDH bits in FLSHCR register

[Han Xu]

> -----Original Message-----
> From: Schrempf Frieder <frieder.schrempf@xxxxxxxxxx>
> Sent: Monday, October 7, 2019 2:23 AM
> To: Han Xu <han.xu@xxxxxxx>; Mark Brown <broonie@xxxxxxxxxx>
> Cc: Schrempf Frieder <frieder.schrempf@xxxxxxxxxx>; stable@xxxxxxxxxxxxxxx;
> linux-spi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: [EXT] [PATCH] spi: spi-fsl-qspi: Clear TDH bits in FLSHCR register
> 
> Caution: EXT Email
> 
> From: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx>
> 
> Later versions of the QSPI controller (e.g. in i.MX6UL/ULL and i.MX7) seem to have
> an additional TDH setting in the FLSHCR register, that needs to be set in accordance
> with the access mode that is used (DDR or SDR).
> 
> Previous bootstages such as BootROM or bootloader might have used the DDR
> mode to access the flash. As we currently only use SDR mode, we need to make
> sure the TDH bits are cleared upon initialization.
> 
> Fixes: 84d043185dbe ("spi: Add a driver for the Freescale/NXP QuadSPI controller")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx>
> ---
>  drivers/spi/spi-fsl-qspi.c | 38 +++++++++++++++++++++++++++++++++-----
>  1 file changed, 33 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/spi/spi-fsl-qspi.c b/drivers/spi/spi-fsl-qspi.c index
> c02e24c01136..63c9f7edaf6c 100644
> --- a/drivers/spi/spi-fsl-qspi.c
> +++ b/drivers/spi/spi-fsl-qspi.c
> @@ -63,6 +63,11 @@
>  #define QUADSPI_IPCR                   0x08
>  #define QUADSPI_IPCR_SEQID(x)          ((x) << 24)
> 
> +#define QUADSPI_FLSHCR                 0x0c
> +#define QUADSPI_FLSHCR_TCSS_MASK       GENMASK(3, 0)
> +#define QUADSPI_FLSHCR_TCSH_MASK       GENMASK(11, 8)
> +#define QUADSPI_FLSHCR_TDH_MASK                GENMASK(17, 16)
> +
>  #define QUADSPI_BUF3CR                 0x1c
>  #define QUADSPI_BUF3CR_ALLMST_MASK     BIT(31)
>  #define QUADSPI_BUF3CR_ADATSZ(x)       ((x) << 8)
> @@ -95,6 +100,9 @@
>  #define QUADSPI_FR                     0x160
>  #define QUADSPI_FR_TFF_MASK            BIT(0)
> 
> +#define QUADSPI_RSER                   0x164
> +#define QUADSPI_RSER_TFIE              BIT(0)
> +
>  #define QUADSPI_SPTRCLR                        0x16c
>  #define QUADSPI_SPTRCLR_IPPTRC         BIT(8)
>  #define QUADSPI_SPTRCLR_BFPTRC         BIT(0)
> @@ -112,9 +120,6 @@
>  #define QUADSPI_LCKER_LOCK             BIT(0)
>  #define QUADSPI_LCKER_UNLOCK           BIT(1)
> 
> -#define QUADSPI_RSER                   0x164
> -#define QUADSPI_RSER_TFIE              BIT(0)
> -
>  #define QUADSPI_LUT_BASE               0x310
>  #define QUADSPI_LUT_OFFSET             (SEQID_LUT * 4 * 4)
>  #define QUADSPI_LUT_REG(idx) \
> @@ -181,6 +186,12 @@
>   */
>  #define QUADSPI_QUIRK_BASE_INTERNAL    BIT(4)
> 
> +/*
> + * Controller uses TDH bits in register QUADSPI_FLSHCR.
> + * They need to be set in accordance with the DDR/SDR mode.
> + */
> +#define QUADSPI_QUIRK_USE_TDH_SETTING  BIT(5)
> +
>  struct fsl_qspi_devtype_data {
>         unsigned int rxfifo;
>         unsigned int txfifo;
> @@ -209,7 +220,8 @@ static const struct fsl_qspi_devtype_data imx7d_data = {
>         .rxfifo = SZ_128,
>         .txfifo = SZ_512,
>         .ahb_buf_size = SZ_1K,
> -       .quirks = QUADSPI_QUIRK_TKT253890 | QUADSPI_QUIRK_4X_INT_CLK,
> +       .quirks = QUADSPI_QUIRK_TKT253890 | QUADSPI_QUIRK_4X_INT_CLK |
> +                 QUADSPI_QUIRK_USE_TDH_SETTING,
>         .little_endian = true,
>  };
> 
> @@ -217,7 +229,8 @@ static const struct fsl_qspi_devtype_data imx6ul_data = {
>         .rxfifo = SZ_128,
>         .txfifo = SZ_512,
>         .ahb_buf_size = SZ_1K,
> -       .quirks = QUADSPI_QUIRK_TKT253890 | QUADSPI_QUIRK_4X_INT_CLK,
> +       .quirks = QUADSPI_QUIRK_TKT253890 | QUADSPI_QUIRK_4X_INT_CLK |
> +                 QUADSPI_QUIRK_USE_TDH_SETTING,
>         .little_endian = true,
>  };
> 
> @@ -275,6 +288,11 @@ static inline int needs_amba_base_offset(struct fsl_qspi *q)
>         return !(q->devtype_data->quirks & QUADSPI_QUIRK_BASE_INTERNAL);  }
> 
> +static inline int needs_tdh_setting(struct fsl_qspi *q) {
> +       return q->devtype_data->quirks & QUADSPI_QUIRK_USE_TDH_SETTING;
> +}
> +
>  /*
>   * An IC bug makes it necessary to rearrange the 32-bit data.
>   * Later chips, such as IMX6SLX, have fixed this bug.
> @@ -710,6 +728,16 @@ static int fsl_qspi_default_setup(struct fsl_qspi *q)
>         qspi_writel(q, QUADSPI_MCR_MDIS_MASK |
> QUADSPI_MCR_RESERVED_MASK,
>                     base + QUADSPI_MCR);
> 
> +       /*
> +        * Previous boot stages (BootROM, bootloader) might have used DDR
> +        * mode and did not clear the TDH bits. As we currently use SDR mode
> +        * only, clear the TDH bits if necessary.
> +        */
> +       if (needs_tdh_setting(q))
> +               qspi_writel(q, qspi_readl(q, base + QUADSPI_FLSHCR) &
> +                           ~QUADSPI_FLSHCR_TDH_MASK,
> +                           base + QUADSPI_FLSHCR);
> +
>         reg = qspi_readl(q, base + QUADSPI_SMPR);
>         qspi_writel(q, reg & ~(QUADSPI_SMPR_FSDLY_MASK
>                         | QUADSPI_SMPR_FSPHS_MASK
> --

Acked-by: Han Xu <han.xu@xxxxxxx>

> 2.17.1