Re: [PATCH v2 08/10] spi: aspeed: Add support for the AST2400 SPI controller

[Joel Stanley]

On Wed, 2 Mar 2022 at 17:31, Cédric Le Goater <clg@xxxxxxxx> wrote:
>
> Extend the driver for the AST2400 SPI Flash Controller (SPI). This
> controller has a slightly different interface which requires
> adaptation of the 4B handling. Summary of features :
>
>    . host Firmware
>    . 1 chip select pin (CE0)
>    . slightly different register set, between AST2500 and the legacy
>      controller
>    . no segment registers
>    . single, dual mode.
>
> Signed-off-by: Cédric Le Goater <clg@xxxxxxxx>

Reviewed-by: Joel Stanley <joel@xxxxxxxxx>

> ---
>  drivers/spi/spi-aspeed-smc.c | 33 ++++++++++++++++++++++++++++++++-
>  1 file changed, 32 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/spi/spi-aspeed-smc.c b/drivers/spi/spi-aspeed-smc.c
> index e133984d3c95..8c6d7f79d97f 100644
> --- a/drivers/spi/spi-aspeed-smc.c
> +++ b/drivers/spi/spi-aspeed-smc.c
> @@ -32,6 +32,7 @@
>  #define   CTRL_IO_DUAL_DATA            BIT(29)
>  #define   CTRL_IO_QUAD_DATA            BIT(30)
>  #define   CTRL_COMMAND_SHIFT           16
> +#define   CTRL_IO_ADDRESS_4B           BIT(13) /* AST2400 SPI only */
>  #define   CTRL_IO_DUMMY_SET(dummy)                                     \
>         (((((dummy) >> 2) & 0x1) << 14) | (((dummy) & 0x3) << 6))
>  #define   CTRL_CE_STOP_ACTIVE          BIT(2)
> @@ -272,6 +273,8 @@ static bool aspeed_spi_supports_op(struct spi_mem *mem, const struct spi_mem_op
>         return spi_mem_default_supports_op(mem, op);
>  }
>
> +static const struct aspeed_spi_data ast2400_spi_data;
> +
>  static int do_aspeed_spi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
>  {
>         struct aspeed_spi *aspi = spi_controller_get_devdata(mem->spi->master);
> @@ -301,6 +304,9 @@ static int do_aspeed_spi_exec_op(struct spi_mem *mem, const struct spi_mem_op *o
>                         addr_mode |= (0x11 << chip->cs);
>                 else
>                         addr_mode &= ~(0x11 << chip->cs);
> +
> +               if (op->addr.nbytes == 4 && chip->aspi->data == &ast2400_spi_data)
> +                       ctl_val |= CTRL_IO_ADDRESS_4B;
>         }
>
>         if (op->dummy.buswidth && op->dummy.nbytes)
> @@ -392,7 +398,13 @@ static int aspeed_spi_chip_set_default_window(struct aspeed_spi_chip *chip)
>         struct aspeed_spi_window windows[ASPEED_SPI_MAX_NUM_CS] = { 0 };
>         struct aspeed_spi_window *win = &windows[chip->cs];
>
> -       aspeed_spi_get_windows(aspi, windows);
> +       /* No segment registers for the AST2400 SPI controller */
> +       if (aspi->data == &ast2400_spi_data) {
> +               win->offset = 0;
> +               win->size = aspi->ahb_window_size;
> +       } else {
> +               aspeed_spi_get_windows(aspi, windows);
> +       }
>
>         chip->ahb_base = aspi->ahb_base + win->offset;
>         chip->ahb_window_size = win->size;
> @@ -455,6 +467,10 @@ static int aspeed_spi_chip_adjust_window(struct aspeed_spi_chip *chip,
>         struct aspeed_spi_window *win = &windows[chip->cs];
>         int ret;
>
> +       /* No segment registers for the AST2400 SPI controller */
> +       if (aspi->data == &ast2400_spi_data)
> +               return 0;
> +
>         /*
>          * Due to an HW issue on the AST2500 SPI controller, the CE0
>          * window size should be smaller than the maximum 128MB.
> @@ -539,6 +555,12 @@ static int aspeed_spi_dirmap_create(struct spi_mem_dirmap_desc *desc)
>                 else
>                         addr_mode &= ~(0x11 << chip->cs);
>                 writel(addr_mode, aspi->regs + CE_CTRL_REG);
> +
> +               /* AST2400 SPI controller sets 4BYTE address mode in
> +                * CE0 Control Register
> +                */
> +               if (op->addr.nbytes == 4 && chip->aspi->data == &ast2400_spi_data)
> +                       ctl_val |= CTRL_IO_ADDRESS_4B;
>         }
>
>         /* READ mode is the controller default setting */
> @@ -805,6 +827,14 @@ static const struct aspeed_spi_data ast2400_fmc_data = {
>         .segment_reg   = aspeed_spi_segment_reg,
>  };
>
> +static const struct aspeed_spi_data ast2400_spi_data = {
> +       .max_cs        = 1,
> +       .hastype       = false,
> +       .we0           = 0,
> +       .ctl0          = 0x04,
> +       /* No segment registers */
> +};
> +
>  static const struct aspeed_spi_data ast2500_fmc_data = {
>         .max_cs        = 3,
>         .hastype       = true,
> @@ -849,6 +879,7 @@ static const struct aspeed_spi_data ast2600_spi_data = {
>
>  static const struct of_device_id aspeed_spi_matches[] = {
>         { .compatible = "aspeed,ast2400-fmc", .data = &ast2400_fmc_data },
> +       { .compatible = "aspeed,ast2400-spi", .data = &ast2400_spi_data },
>         { .compatible = "aspeed,ast2500-fmc", .data = &ast2500_fmc_data },
>         { .compatible = "aspeed,ast2500-spi", .data = &ast2500_spi_data },
>         { .compatible = "aspeed,ast2600-fmc", .data = &ast2600_fmc_data },
> --
> 2.34.1
>