[PATCH] mmc: meson-gx: add SDIO interrupt support

[Ulf Hansson]

On Sun, 14 Aug 2022 at 23:44, Heiner Kallweit <hkallweit1 at gmail.com> wrote:
>
> This adds SDIO interrupt support.
> Successfully tested on a S905X4-based system with a BRCM4334
> SDIO wifi module (brcmfmac driver).
>
> Signed-off-by: Heiner Kallweit <hkallweit1 at gmail.com>
> ---
>  drivers/mmc/host/meson-gx-mmc.c | 45 +++++++++++++++++++++++++--------
>  1 file changed, 34 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
> index 2f08d442e..e8d53fcdd 100644
> --- a/drivers/mmc/host/meson-gx-mmc.c
> +++ b/drivers/mmc/host/meson-gx-mmc.c
> @@ -41,14 +41,17 @@
>  #define   CLK_V2_TX_DELAY_MASK GENMASK(19, 16)
>  #define   CLK_V2_RX_DELAY_MASK GENMASK(23, 20)
>  #define   CLK_V2_ALWAYS_ON BIT(24)
> +#define   CLK_V2_IRQ_SDIO_SLEEP BIT(29)
>
>  #define   CLK_V3_TX_DELAY_MASK GENMASK(21, 16)
>  #define   CLK_V3_RX_DELAY_MASK GENMASK(27, 22)
>  #define   CLK_V3_ALWAYS_ON BIT(28)
> +#define   CLK_V3_IRQ_SDIO_SLEEP BIT(29)
>
>  #define   CLK_TX_DELAY_MASK(h)         (h->data->tx_delay_mask)
>  #define   CLK_RX_DELAY_MASK(h)         (h->data->rx_delay_mask)
>  #define   CLK_ALWAYS_ON(h)             (h->data->always_on)
> +#define   CLK_IRQ_SDIO_SLEEP(h)                (h->data->irq_sdio_sleep)
>
>  #define SD_EMMC_DELAY 0x4
>  #define SD_EMMC_ADJUST 0x8
> @@ -100,9 +103,6 @@
>  #define   IRQ_END_OF_CHAIN BIT(13)
>  #define   IRQ_RESP_STATUS BIT(14)
>  #define   IRQ_SDIO BIT(15)
> -#define   IRQ_EN_MASK \
> -       (IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN | IRQ_RESP_STATUS |\
> -        IRQ_SDIO)
>
>  #define SD_EMMC_CMD_CFG 0x50
>  #define SD_EMMC_CMD_ARG 0x54
> @@ -136,6 +136,7 @@ struct meson_mmc_data {
>         unsigned int rx_delay_mask;
>         unsigned int always_on;
>         unsigned int adjust;
> +       unsigned int irq_sdio_sleep;
>  };
>
>  struct sd_emmc_desc {
> @@ -431,6 +432,7 @@ static int meson_mmc_clk_init(struct meson_host *host)
>         clk_reg |= FIELD_PREP(CLK_CORE_PHASE_MASK, CLK_PHASE_180);
>         clk_reg |= FIELD_PREP(CLK_TX_PHASE_MASK, CLK_PHASE_0);
>         clk_reg |= FIELD_PREP(CLK_RX_PHASE_MASK, CLK_PHASE_0);
> +       clk_reg |= CLK_IRQ_SDIO_SLEEP(host);
>         writel(clk_reg, host->regs + SD_EMMC_CLOCK);
>
>         /* get the mux parents */
> @@ -933,7 +935,6 @@ static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
>  {
>         struct meson_host *host = dev_id;
>         struct mmc_command *cmd;
> -       struct mmc_data *data;
>         u32 irq_en, status, raw_status;
>         irqreturn_t ret = IRQ_NONE;
>
> @@ -948,14 +949,24 @@ static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
>                 return IRQ_NONE;
>         }
>
> -       if (WARN_ON(!host) || WARN_ON(!host->cmd))
> +       if (WARN_ON(!host))
>                 return IRQ_NONE;
>
>         /* ack all raised interrupts */
>         writel(status, host->regs + SD_EMMC_STATUS);
>
>         cmd = host->cmd;
> -       data = cmd->data;
> +
> +       if (status & IRQ_SDIO) {
> +               mmc_signal_sdio_irq(host->mmc);

This is the legacy interface for supporting SDIO irqs. I am planning
to remove it, sooner or later.

Please convert into using sdio_signal_irq() instead. Note that, using
sdio_signal_irq() means you need to implement support for
MMC_CAP2_SDIO_IRQ_NOTHREAD, which also includes to implement the
->ack_sdio_irq() callback.

There are other host drivers to be inspired from, but don't hesitate
to ask if there is something unclear.

[...]

Kind regards
Uffe