[PATCH 1/2] mmc: sdhci-of-dwcmshc: Add command queue support for rockchip SOCs

[Sebastian Reichel <sebastian.reichel@collabora.com>]

This adds CQE support for the Rockchip RK3588 and RK3576 platform. To
be functional, the eMMC device-tree node must have a 'supports-cqe;'
flag property.

As the RK3576 devicet-tree has been upstreamed with the 'supports-cqe;'
property set by default, the kernel already tried to use CQE, which
results in system hang during suspend. This fixes the issue.

Co-developed-by: Yifeng Zhao <yifeng.zhao@rock-chips.com>
Signed-off-by: Yifeng Zhao <yifeng.zhao@rock-chips.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
 drivers/mmc/host/sdhci-of-dwcmshc.c | 85 +++++++++++++++++++++++++++++++++++--
 1 file changed, 82 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
index eebd45389956..f533c98d5db1 100644
--- a/drivers/mmc/host/sdhci-of-dwcmshc.c
+++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
@@ -24,6 +24,7 @@
 
 #include "sdhci-pltfm.h"
 #include "cqhci.h"
+#include "sdhci-cqhci.h"
 
 #define SDHCI_DWCMSHC_ARG2_STUFF	GENMASK(31, 16)
 
@@ -82,6 +83,8 @@
 #define DWCMSHC_EMMC_DLL_TXCLK		0x808
 #define DWCMSHC_EMMC_DLL_STRBIN		0x80c
 #define DECMSHC_EMMC_DLL_CMDOUT		0x810
+#define DECMSHC_EMMC_MISC_CON		0x81C
+#define MISC_INTCLK_EN			BIT(1)
 #define DWCMSHC_EMMC_DLL_STATUS0	0x840
 #define DWCMSHC_EMMC_DLL_START		BIT(0)
 #define DWCMSHC_EMMC_DLL_LOCKED		BIT(8)
@@ -234,6 +237,7 @@ struct dwcmshc_priv {
 
 struct dwcmshc_pltfm_data {
 	const struct sdhci_pltfm_data pdata;
+	const struct cqhci_host_ops *cqhci_host_ops;
 	int (*init)(struct device *dev, struct sdhci_host *host, struct dwcmshc_priv *dwc_priv);
 	void (*postinit)(struct sdhci_host *host, struct dwcmshc_priv *dwc_priv);
 };
@@ -561,6 +565,61 @@ static void dwcmshc_cqhci_dumpregs(struct mmc_host *mmc)
 	sdhci_dumpregs(mmc_priv(mmc));
 }
 
+static void rk35xx_sdhci_cqe_enable(struct mmc_host *mmc)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct dwcmshc_priv *dwc_priv = sdhci_pltfm_priv(pltfm_host);
+	u32 reg;
+
+	reg = sdhci_readl(host, dwc_priv->vendor_specific_area2 + CQHCI_CFG);
+	reg |= CQHCI_ENABLE;
+	sdhci_writel(host, reg, dwc_priv->vendor_specific_area2 + CQHCI_CFG);
+
+	reg = sdhci_readl(host, SDHCI_PRESENT_STATE);
+	while (reg & SDHCI_DATA_AVAILABLE) {
+		sdhci_readl(host, SDHCI_BUFFER);
+		reg = sdhci_readl(host, SDHCI_PRESENT_STATE);
+	}
+
+	sdhci_writew(host, DWCMSHC_SDHCI_CQE_TRNS_MODE, SDHCI_TRANSFER_MODE);
+
+	sdhci_cqe_enable(mmc);
+
+	sdhci_writew(host, DWCMSHC_SDHCI_CQE_TRNS_MODE, SDHCI_TRANSFER_MODE);
+}
+
+static void rk35xx_sdhci_cqe_disabled(struct mmc_host *mmc, bool recovery)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct dwcmshc_priv *dwc_priv = sdhci_pltfm_priv(pltfm_host);
+	unsigned long flags;
+	u32 ctrl;
+
+	mmc->cqe_ops->cqe_wait_for_idle(mmc);
+	spin_lock_irqsave(&host->lock, flags);
+
+	/*
+	 * During CQE command transfers, command complete bit gets latched.
+	 * So s/w should clear command complete interrupt status when CQE is
+	 * either halted or disabled. Otherwise unexpected SDCHI legacy
+	 * interrupt gets triggered when CQE is halted/disabled.
+	 */
+	ctrl = sdhci_readl(host, SDHCI_INT_ENABLE);
+	ctrl |= SDHCI_INT_RESPONSE;
+	sdhci_writel(host,  ctrl, SDHCI_INT_ENABLE);
+	sdhci_writel(host, SDHCI_INT_RESPONSE, SDHCI_INT_STATUS);
+
+	spin_unlock_irqrestore(&host->lock, flags);
+
+	sdhci_cqe_disable(mmc, recovery);
+
+	ctrl = sdhci_readl(host, dwc_priv->vendor_specific_area2 + CQHCI_CFG);
+	ctrl &= ~CQHCI_ENABLE;
+	sdhci_writel(host, ctrl, dwc_priv->vendor_specific_area2 + CQHCI_CFG);
+}
+
 static void dwcmshc_rk3568_set_clock(struct sdhci_host *host, unsigned int clock)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -679,6 +738,10 @@ static void rk35xx_sdhci_reset(struct sdhci_host *host, u8 mask)
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 	struct dwcmshc_priv *dwc_priv = sdhci_pltfm_priv(pltfm_host);
 	struct rk35xx_priv *priv = dwc_priv->priv;
+	u32 extra = sdhci_readl(host, DECMSHC_EMMC_MISC_CON);
+
+	if ((host->mmc->caps2 & MMC_CAP2_CQE) && (mask & SDHCI_RESET_ALL))
+		cqhci_deactivate(host->mmc);
 
 	if (mask & SDHCI_RESET_ALL && priv->reset) {
 		reset_control_assert(priv->reset);
@@ -687,6 +750,9 @@ static void rk35xx_sdhci_reset(struct sdhci_host *host, u8 mask)
 	}
 
 	sdhci_reset(host, mask);
+
+	/* Enable INTERNAL CLOCK */
+	sdhci_writel(host, MISC_INTCLK_EN | extra, DECMSHC_EMMC_MISC_CON);
 }
 
 static int dwcmshc_rk35xx_init(struct device *dev, struct sdhci_host *host,
@@ -1188,6 +1254,13 @@ static const struct dwcmshc_pltfm_data sdhci_dwcmshc_bf3_pdata = {
 };
 #endif
 
+static const struct cqhci_host_ops rk35xx_cqhci_ops = {
+	.enable		= rk35xx_sdhci_cqe_enable,
+	.disable	= rk35xx_sdhci_cqe_disabled,
+	.dumpregs	= dwcmshc_cqhci_dumpregs,
+	.set_tran_desc	= dwcmshc_set_tran_desc,
+};
+
 static const struct dwcmshc_pltfm_data sdhci_dwcmshc_rk35xx_pdata = {
 	.pdata = {
 		.ops = &sdhci_dwcmshc_rk35xx_ops,
@@ -1196,6 +1269,7 @@ static const struct dwcmshc_pltfm_data sdhci_dwcmshc_rk35xx_pdata = {
 		.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
 			   SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN,
 	},
+	.cqhci_host_ops = &rk35xx_cqhci_ops,
 	.init = dwcmshc_rk35xx_init,
 	.postinit = dwcmshc_rk35xx_postinit,
 };
@@ -1245,7 +1319,9 @@ static const struct cqhci_host_ops dwcmshc_cqhci_ops = {
 	.set_tran_desc	= dwcmshc_set_tran_desc,
 };
 
-static void dwcmshc_cqhci_init(struct sdhci_host *host, struct platform_device *pdev)
+static void dwcmshc_cqhci_init(struct sdhci_host *host,
+			       struct platform_device *pdev,
+			       const struct dwcmshc_pltfm_data *pltfm_data)
 {
 	struct cqhci_host *cq_host;
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -1275,7 +1351,10 @@ static void dwcmshc_cqhci_init(struct sdhci_host *host, struct platform_device *
 	}
 
 	cq_host->mmio = host->ioaddr + priv->vendor_specific_area2;
-	cq_host->ops = &dwcmshc_cqhci_ops;
+	if (pltfm_data->cqhci_host_ops)
+		cq_host->ops = pltfm_data->cqhci_host_ops;
+	else
+		cq_host->ops = &dwcmshc_cqhci_ops;
 
 	/* Enable using of 128-bit task descriptors */
 	dma64 = host->flags & SDHCI_USE_64_BIT_DMA;
@@ -1443,7 +1522,7 @@ static int dwcmshc_probe(struct platform_device *pdev)
 		priv->vendor_specific_area2 =
 			sdhci_readw(host, DWCMSHC_P_VENDOR_AREA2);
 
-		dwcmshc_cqhci_init(host, pdev);
+		dwcmshc_cqhci_init(host, pdev, pltfm_data);
 	}
 
 	if (pltfm_data->postinit)

-- 
2.51.0