Re: [PATCH v5 2/3] rockchip: sdhci: Add HS400 Enhanced Strobe support for RK3399

On 2022/3/16 01:46, Alper Nebi Yasak wrote:

On RK3399, a register bit must be set to enable Enhanced Strobe. Let the Rockchip SDHCI driver set it when Enhanced Strobe configuration is requested. However, having it set makes the lower-speed modes stop working and makes reinitialization fail, so let it be unset as needed in set_control_reg().

This is mostly ported from Linux's Arasan SDHCI driver which happens to be the underlying IP. (drivers/mmc/host/sdhci-of-arasan.c in Linux tree).

Signed-off-by: Alper Nebi Yasak alpernebiyasak@gmail.com Reviewed-by: Jaehoon Chung jh80.chung@samsung.com

Reviewed-by: Kever Yang kever.yang@rock-chips.com

Thanks, - Kever

---

Changes in v5:

• Add tag: "Reviewed-by: Jaehoon Chung jh80.chung@samsung.com"

Changes in v4:

• Add comment for Rockchip SDHCI set_enhanced_strobe() driver data op

Changes in v2:

• Unset ES bit in rk3399 set_control_reg() to fix a reinit issue

• Don't use unnecessary & for function pointer in ops struct

• Rename rk3399_set_enhanced_strobe -> rk3399_sdhci_set_enhanced_strobe

• Let set_enhanced_strobe() unset the ES bit if mode is not HS400_ES

  drivers/mmc/rockchip_sdhci.c | 53 ++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+)

diff --git a/drivers/mmc/rockchip_sdhci.c b/drivers/mmc/rockchip_sdhci.c index b91df05de4ff..f4d5a59036a2 100644 --- a/drivers/mmc/rockchip_sdhci.c +++ b/drivers/mmc/rockchip_sdhci.c @@ -42,6 +42,9 @@ ((((x) >> PHYCTRL_DLLRDY_SHIFT) & PHYCTRL_DLLRDY_MASK) ==\ PHYCTRL_DLLRDY_DONE)

+#define ARASAN_VENDOR_REGISTER 0x78 +#define ARASAN_VENDOR_ENHANCED_STROBE BIT(0)

• /* Rockchip specific Registers */ #define DWCMSHC_EMMC_DLL_CTRL 0x800 #define DWCMSHC_EMMC_DLL_CTRL_RESET BIT(1)

@@ -117,6 +120,19 @@ struct sdhci_data { * Return: 0 if successful, -ve on error */ int (*set_ios_post)(struct sdhci_host *host);

• /**

• * set_enhanced_strobe() - Set HS400 Enhanced Strobe config
  

• *
  

• * This is the set_enhanced_strobe() SDHCI operation that should
  

• * be used for the hardware this driver data is associated with.
  

• * Normally, this is used to set any host-specific configuration
  

• * necessary for HS400 ES.
  

• *
  

• * @host: SDHCI host structure
  

• * Return: 0 if successful, -ve on error
  

• */
  

• int (*set_enhanced_strobe)(struct sdhci_host *host); };

  static int rk3399_emmc_phy_init(struct udevice *dev)

@@ -206,6 +222,21 @@ static int rk3399_emmc_get_phy(struct udevice *dev) return 0; }

+static int rk3399_sdhci_set_enhanced_strobe(struct sdhci_host *host) +{

• struct mmc *mmc = host->mmc;
• u32 vendor;
• vendor = sdhci_readl(host, ARASAN_VENDOR_REGISTER);
• if (mmc->selected_mode == MMC_HS_400_ES)

• vendor |= ARASAN_VENDOR_ENHANCED_STROBE;
  

• else

• vendor &= ~ARASAN_VENDOR_ENHANCED_STROBE;
  

• sdhci_writel(host, vendor, ARASAN_VENDOR_REGISTER);
• return 0;

+}

• static void rk3399_sdhci_set_control_reg(struct sdhci_host *host) { struct rockchip_sdhc *priv = container_of(host, struct rockchip_sdhc, host);

@@ -217,6 +248,15 @@ static void rk3399_sdhci_set_control_reg(struct sdhci_host *host) rk3399_emmc_phy_power_off(priv->phy);

sdhci_set_control_reg(host);

• /*

• * Reinitializing the device tries to set it to lower-speed modes
  

• * first, which fails if the Enhanced Strobe bit is set, making
  

• * the device impossible to use. Set the correct value here to
  

• * let reinitialization attempts succeed.
  

• */
  

• if (CONFIG_IS_ENABLED(MMC_HS400_ES_SUPPORT))

• rk3399_sdhci_set_enhanced_strobe(host);
  

  };

  static int rk3399_sdhci_set_ios_post(struct sdhci_host *host)

@@ -409,10 +449,22 @@ static int rockchip_sdhci_execute_tuning(struct mmc *mmc, u8 opcode) return ret; }

+static int rockchip_sdhci_set_enhanced_strobe(struct sdhci_host *host) +{

• struct rockchip_sdhc *priv = container_of(host, struct rockchip_sdhc, host);
• struct sdhci_data *data = (struct sdhci_data *)dev_get_driver_data(priv->dev);
• if (data->set_enhanced_strobe)

• return data->set_enhanced_strobe(host);
  

• return -ENOTSUPP;

+}

• static struct sdhci_ops rockchip_sdhci_ops = { .set_ios_post = rockchip_sdhci_set_ios_post, .platform_execute_tuning = &rockchip_sdhci_execute_tuning, .set_control_reg = rockchip_sdhci_set_control_reg,

• .set_enhanced_strobe = rockchip_sdhci_set_enhanced_strobe, };

  static int rockchip_sdhci_probe(struct udevice *dev)

@@ -495,6 +547,7 @@ static const struct sdhci_data rk3399_data = { .emmc_phy_init = rk3399_emmc_phy_init, .set_control_reg = rk3399_sdhci_set_control_reg, .set_ios_post = rk3399_sdhci_set_ios_post,

• .set_enhanced_strobe = rk3399_sdhci_set_enhanced_strobe, };

  static const struct sdhci_data rk3568_data = {