Re: [PATCH v13 13/15] mmc: sdhci-cadence: Add AMD Pensando Elba SoC support
From: Ulf Hansson
Date: Mon Apr 17 2023 - 10:55:35 EST
On Mon, 10 Apr 2023 at 20:47, Brad Larson <blarson@xxxxxxx> wrote:
>
> Add support for AMD Pensando Elba SoC which explicitly
> controls byte-lane enables on writes.
>
> Select MMC_SDHCI_IO_ACCESSORS for MMC_SDHCI_CADENCE which
> allows Elba SoC sdhci_elba_ops to overwrite the SDHCI
> IO memory accessors
>
> Signed-off-by: Brad Larson <blarson@xxxxxxx>
> Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Applied for next, thanks!
Kind regards
Uffe
> ---
>
> v13 changes:
> - Use GENMASK(7, 3) in elba_priv_writel() to set all byte enables
> - Add a variable 'shift' with GENMASK(1, 0) in elba_write_w() and
> elba_write_b() to set the byte enable variable.
>
> v11 changes:
> - Remove elba-drv_init() call to platform_get_resource() since that
> check is done inside devm_platform_ioremap_resource()
> - Move spin_lock_init() before error check
> - Remove extra parentheses
>
> v10 changes:
> - Add Elba specific support into this 3rd patch. This builds on the private
> writel() enabled in patch 1 followed by platform specific init() in patch 2.
> - Specify when first used the reason for the spinlock use to order byte-enable
> prior to write data.
>
> ---
> drivers/mmc/host/Kconfig | 1 +
> drivers/mmc/host/sdhci-cadence.c | 98 ++++++++++++++++++++++++++++++++
> 2 files changed, 99 insertions(+)
>
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index 4745fe217ade..9f793892123c 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -255,6 +255,7 @@ config MMC_SDHCI_CADENCE
> tristate "SDHCI support for the Cadence SD/SDIO/eMMC controller"
> depends on MMC_SDHCI_PLTFM
> depends on OF
> + select MMC_SDHCI_IO_ACCESSORS
> help
> This selects the Cadence SD/SDIO/eMMC driver.
>
> diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c
> index c528a25f48b8..5d1e9cef74f5 100644
> --- a/drivers/mmc/host/sdhci-cadence.c
> +++ b/drivers/mmc/host/sdhci-cadence.c
> @@ -66,6 +66,8 @@ struct sdhci_cdns_phy_param {
>
> struct sdhci_cdns_priv {
> void __iomem *hrs_addr;
> + void __iomem *ctl_addr; /* write control */
> + spinlock_t wrlock; /* write lock */
> bool enhanced_strobe;
> void (*priv_writel)(struct sdhci_cdns_priv *priv, u32 val, void __iomem *reg);
> unsigned int nr_phy_params;
> @@ -321,6 +323,91 @@ static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
> sdhci_set_uhs_signaling(host, timing);
> }
>
> +/* Elba control register bits [6:3] are byte-lane enables */
> +#define ELBA_BYTE_ENABLE_MASK(x) ((x) << 3)
> +
> +/*
> + * The Pensando Elba SoC explicitly controls byte-lane enabling on writes
> + * which includes writes to the HRS registers. The write lock (wrlock)
> + * is used to ensure byte-lane enable, using write control (ctl_addr),
> + * occurs before the data write.
> + */
> +static void elba_priv_writel(struct sdhci_cdns_priv *priv, u32 val,
> + void __iomem *reg)
> +{
> + unsigned long flags;
> +
> + spin_lock_irqsave(&priv->wrlock, flags);
> + writel(GENMASK(7, 3), priv->ctl_addr);
> + writel(val, reg);
> + spin_unlock_irqrestore(&priv->wrlock, flags);
> +}
> +
> +static void elba_write_l(struct sdhci_host *host, u32 val, int reg)
> +{
> + elba_priv_writel(sdhci_cdns_priv(host), val, host->ioaddr + reg);
> +}
> +
> +static void elba_write_w(struct sdhci_host *host, u16 val, int reg)
> +{
> + struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
> + u32 shift = reg & GENMASK(1, 0);
> + unsigned long flags;
> + u32 byte_enables;
> +
> + byte_enables = GENMASK(1, 0) << shift;
> + spin_lock_irqsave(&priv->wrlock, flags);
> + writel(ELBA_BYTE_ENABLE_MASK(byte_enables), priv->ctl_addr);
> + writew(val, host->ioaddr + reg);
> + spin_unlock_irqrestore(&priv->wrlock, flags);
> +}
> +
> +static void elba_write_b(struct sdhci_host *host, u8 val, int reg)
> +{
> + struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
> + u32 shift = reg & GENMASK(1, 0);
> + unsigned long flags;
> + u32 byte_enables;
> +
> + byte_enables = BIT(0) << shift;
> + spin_lock_irqsave(&priv->wrlock, flags);
> + writel(ELBA_BYTE_ENABLE_MASK(byte_enables), priv->ctl_addr);
> + writeb(val, host->ioaddr + reg);
> + spin_unlock_irqrestore(&priv->wrlock, flags);
> +}
> +
> +static const struct sdhci_ops sdhci_elba_ops = {
> + .write_l = elba_write_l,
> + .write_w = elba_write_w,
> + .write_b = elba_write_b,
> + .set_clock = sdhci_set_clock,
> + .get_timeout_clock = sdhci_cdns_get_timeout_clock,
> + .set_bus_width = sdhci_set_bus_width,
> + .reset = sdhci_reset,
> + .set_uhs_signaling = sdhci_cdns_set_uhs_signaling,
> +};
> +
> +static int elba_drv_init(struct platform_device *pdev)
> +{
> + struct sdhci_host *host = platform_get_drvdata(pdev);
> + struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
> + void __iomem *ioaddr;
> +
> + host->mmc->caps |= MMC_CAP_1_8V_DDR | MMC_CAP_8_BIT_DATA;
> + spin_lock_init(&priv->wrlock);
> +
> + /* Byte-lane control register */
> + ioaddr = devm_platform_ioremap_resource(pdev, 1);
> + if (IS_ERR(ioaddr))
> + return PTR_ERR(ioaddr);
> +
> + priv->ctl_addr = ioaddr;
> + priv->priv_writel = elba_priv_writel;
> + writel(ELBA_BYTE_ENABLE_MASK(0xf), priv->ctl_addr);
> +
> + return 0;
> +}
> +
> static const struct sdhci_ops sdhci_cdns_ops = {
> .set_clock = sdhci_set_clock,
> .get_timeout_clock = sdhci_cdns_get_timeout_clock,
> @@ -337,6 +424,13 @@ static const struct sdhci_cdns_drv_data sdhci_cdns_uniphier_drv_data = {
> },
> };
>
> +static const struct sdhci_cdns_drv_data sdhci_elba_drv_data = {
> + .init = elba_drv_init,
> + .pltfm_data = {
> + .ops = &sdhci_elba_ops,
> + },
> +};
> +
> static const struct sdhci_cdns_drv_data sdhci_cdns_drv_data = {
> .pltfm_data = {
> .ops = &sdhci_cdns_ops,
> @@ -477,6 +571,10 @@ static const struct of_device_id sdhci_cdns_match[] = {
> .compatible = "socionext,uniphier-sd4hc",
> .data = &sdhci_cdns_uniphier_drv_data,
> },
> + {
> + .compatible = "amd,pensando-elba-sd4hc",
> + .data = &sdhci_elba_drv_data,
> + },
> { .compatible = "cdns,sd4hc" },
> { /* sentinel */ }
> };
> --
> 2.17.1
>