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From:   Joel Stanley <joel@jms.id.au>
Date:   Wed, 2 Mar 2022 22:30:08 +0000
Message-ID: <CACPK8Xesu-3cfH+fPvNGW=JfntTarTSv1njb1FBZ7pD2-TMbMA@mail.gmail.com>
Subject: Re: [PATCH v2 07/10] spi: aspeed: Workaround AST2500 limitations
To:     =?UTF-8?Q?C=C3=A9dric_Le_Goater?= <clg@kaod.org>
Cc:     linux-spi@vger.kernel.org,
        linux-mtd <linux-mtd@lists.infradead.org>,
        Mark Brown <broonie@kernel.org>,
        Tudor Ambarus <tudor.ambarus@microchip.com>,
        Pratyush Yadav <p.yadav@ti.com>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        linux-aspeed <linux-aspeed@lists.ozlabs.org>,
        Andrew Jeffery <andrew@aj.id.au>,
        Chin-Ting Kuo <chin-ting_kuo@aspeedtech.com>,
        devicetree <devicetree@vger.kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Wed, 2 Mar 2022 at 17:31, C=C3=A9dric Le Goater <clg@kaod.org> wrote:
>
> It is not possible to configure a full 128MB window for a chip of the
> same size on the AST2500 SPI controller. For his case, the maximum

typo: this

> window size is restricted to 120MB for CE0.
>
> Signed-off-by: C=C3=A9dric Le Goater <clg@kaod.org>

Reviewed-by: Joel Stanley <joel@jms.id.au>

> ---
>  drivers/spi/spi-aspeed-smc.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/drivers/spi/spi-aspeed-smc.c b/drivers/spi/spi-aspeed-smc.c
> index 974ab215ec34..e133984d3c95 100644
> --- a/drivers/spi/spi-aspeed-smc.c
> +++ b/drivers/spi/spi-aspeed-smc.c
> @@ -445,6 +445,8 @@ static int aspeed_spi_set_window(struct aspeed_spi *a=
spi,
>   * - ioremap each window, not strictly necessary since the overall windo=
w
>   *   is correct.
>   */
> +static const struct aspeed_spi_data ast2500_spi_data;
> +
>  static int aspeed_spi_chip_adjust_window(struct aspeed_spi_chip *chip,
>                                          u32 local_offset, u32 size)
>  {
> @@ -453,6 +455,16 @@ static int aspeed_spi_chip_adjust_window(struct aspe=
ed_spi_chip *chip,
>         struct aspeed_spi_window *win =3D &windows[chip->cs];
>         int ret;
>
> +       /*
> +        * Due to an HW issue on the AST2500 SPI controller, the CE0
> +        * window size should be smaller than the maximum 128MB.
> +        */
> +       if (aspi->data =3D=3D &ast2500_spi_data && chip->cs =3D=3D 0 && s=
ize =3D=3D SZ_128M) {
> +               size =3D 120 << 20;
> +               dev_info(aspi->dev, "CE%d window resized to %dMB (AST2500=
 HW quirk)",
> +                        chip->cs, size >> 20);
> +       }
> +
>         aspeed_spi_get_windows(aspi, windows);
>
>         /* Adjust this chip window */
> --
> 2.34.1
>