On Mon, 6 Dec 2021 at 15:29, Mårten Lindahl <marten.lindahl@xxxxxxxx> wrote:
>
> Current dw_mci driver supports a TMOUT register which consists of a 24
> bit field (TMOUT[31:8]) for the DATA_TIMEOUT. The maximum value of this
> field is 0xFFFFFF, which with a 200MHz clock will give a full DRTO of:
>
> 0xFFFFFF / 200000000 => ~84 ms
>
> However, the ARTPEC-8 SoC DWMMC IP version has a TMOUT register with an
> extended DATA_TIMEOUT field, which supports longer timers for the DRTO.
> In this version the DATA_TIMEOUT field is split into two, which with the
> same 200MHz clock as above will allow a maximum timeout of:
>
> ((TMOUT[10:8] -1) * 0xFFFFFF + TMOUT[31:11] * 8) / 200000000 => ~587 ms
>
> Add a quirk to support this. The quirk is enabled for ARTPEC-8 SoCs.
>
> Signed-off-by: Mårten Lindahl <marten.lindahl@xxxxxxxx>
> ---
>
> v2:
> - Removed unnecessary comment
> - Change 1<<0 to BIT(0)
>
> drivers/mmc/host/dw_mmc-exynos.c | 5 +++++
> drivers/mmc/host/dw_mmc.c | 33 ++++++++++++++++++++++++++++----
> drivers/mmc/host/dw_mmc.h | 6 ++++++
> 3 files changed, 40 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
> index 86486e6659de..1b625642c5b4 100644
> --- a/drivers/mmc/host/dw_mmc-exynos.c
> +++ b/drivers/mmc/host/dw_mmc-exynos.c
> @@ -127,6 +127,11 @@ static int dw_mci_exynos_priv_init(struct dw_mci *host)
> DQS_CTRL_GET_RD_DELAY(priv->saved_strobe_ctrl);
> }
>
> + if (priv->ctrl_type == DW_MCI_TYPE_ARTPEC8) {
> + /* Quirk needed for ARTPEC-8 SoCs */
> + host->quirks |= DW_MMC_QUIRK_EXTENDED_TMOUT;
> + }
> +
> host->bus_hz /= (priv->ciu_div + 1);
>
> return 0;
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index f2a14a434bef..45ea9fd97a6a 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -1289,6 +1289,7 @@ static void dw_mci_set_data_timeout(struct dw_mci *host,
> {
> u32 clk_div, tmout;
> u64 tmp;
> + unsigned int tmp2;
>
> clk_div = (mci_readl(host, CLKDIV) & 0xFF) * 2;
> if (clk_div == 0)
> @@ -1301,10 +1302,28 @@ static void dw_mci_set_data_timeout(struct dw_mci *host,
> tmout = 0xFF; /* Set maximum */
>
> /* TMOUT[31:8] (DATA_TIMEOUT) */
> - if (!tmp || tmp > 0xFFFFFF)
> - tmout |= (0xFFFFFF << 8);
> - else
> - tmout |= (tmp & 0xFFFFFF) << 8;
> + if (host->quirks & DW_MMC_QUIRK_EXTENDED_TMOUT) {
Adding an option for dealing with quirks, should be avoided if
possible. That's because we want to avoid sprinkling common dw_mmc
code with variant specific code, as it will sooner or later turn into
a nightmare to maintain.
In this case, I suggest you look into extending the struct
dw_mci_drv_data with some new callback (perhaps ->set_data_timeout())
and then implement it for your variant.
If that callback is present, it should take precedence over the
generic dw_mci_set_data_timeout(), if you get what I mean.
Moreover, if some common dw_mmc code needs to be called from your
callback, I suggest we make that code available through exported
dw_mmc library functions instead.
> + /*
> + * Extended HW timer (max = 0x6FFFFF2):
> + * ((TMOUT[10:8] - 1) * 0xFFFFFF + TMOUT[31:11] * 8)
> + */
> + if (!tmp || tmp > 0x6FFFFF2)
> + tmout |= (0xFFFFFF << 8);
> + else {
> + /* TMOUT[10:8] */
> + tmp2 = (((unsigned int)tmp / 0xFFFFFF) + 1) & 0x7;
> + tmout |= tmp2 << 8;
> +
> + /* TMOUT[31:11] */
> + tmp = tmp - ((tmp2 - 1) * 0xFFFFFF);
> + tmout |= (tmp & 0xFFFFF8) << 8;
> + }
> + } else {
> + if (!tmp || tmp > 0xFFFFFF)
> + tmout |= (0xFFFFFF << 8);
> + else
> + tmout |= (tmp & 0xFFFFFF) << 8;
> + }
>
> mci_writel(host, TMOUT, tmout);
> dev_dbg(host->dev, "timeout_ns: %u => TMOUT[31:8]: 0x%#08x",
> @@ -2005,9 +2024,15 @@ static void dw_mci_set_drto(struct dw_mci *host)
> if (drto_div == 0)
> drto_div = 1;
>
> + if (host->quirks & DW_MMC_QUIRK_EXTENDED_TMOUT)
> + drto_clks = (((drto_clks & 0x7) - 1) * 0xFFFFFF) +
> + ((drto_clks & 0xFFFFF8));
> +
> drto_ms = DIV_ROUND_UP_ULL((u64)MSEC_PER_SEC * drto_clks * drto_div,
> host->bus_hz);
>
> + dev_dbg(host->dev, "drto_ms: %u\n", drto_ms);
> +
> /* add a bit spare time */
> drto_ms += 10;
>
> diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
> index 771d5afa3136..3b6510d4a684 100644
> --- a/drivers/mmc/host/dw_mmc.h
> +++ b/drivers/mmc/host/dw_mmc.h
> @@ -118,6 +118,7 @@ struct dw_mci_dma_slave {
> * @part_buf: Simple buffer for partial fifo reads/writes.
> * @push_data: Pointer to FIFO push function.
> * @pull_data: Pointer to FIFO pull function.
> + * @quirks: Set of quirks that apply to specific versions of the IP.
> * @vqmmc_enabled: Status of vqmmc, should be true or false.
> * @irq_flags: The flags to be passed to request_irq.
> * @irq: The irq value to be passed to request_irq.
> @@ -223,6 +224,8 @@ struct dw_mci {
> void (*push_data)(struct dw_mci *host, void *buf, int cnt);
> void (*pull_data)(struct dw_mci *host, void *buf, int cnt);
>
> + u32 quirks;
> +
> bool vqmmc_enabled;
> unsigned long irq_flags; /* IRQ flags */
> int irq;
> @@ -274,6 +277,9 @@ struct dw_mci_board {
> struct dma_pdata *data;
> };
>
> +/* Support for longer data read timeout */
> +#define DW_MMC_QUIRK_EXTENDED_TMOUT BIT(0)
> +
> #define DW_MMC_240A 0x240a
> #define DW_MMC_280A 0x280a
>
Kind regards
Uffe
