mmc: sdhci-esdhc-imx: add CMDQ support

Add CMDQ support for imx8qm/imx8qxp.
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
[Ulf: Rebased on top of latest changes]
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/Kconfig

@@ -224,6 +224,7 @@ config MMC_SDHCI_ESDHC_IMX
 	depends on ARCH_MXC
 	depends on MMC_SDHCI_PLTFM
 	select MMC_SDHCI_IO_ACCESSORS
+	select MMC_CQHCI
 	help
 	  This selects the Freescale eSDHC/uSDHC controller support
 	  found on i.MX25, i.MX35 i.MX5x and i.MX6x.

drivers/mmc/host/sdhci-esdhc-imx.c

@@ -25,6 +25,7 @@
 #include <linux/pm_runtime.h>
 #include "sdhci-pltfm.h"
 #include "sdhci-esdhc.h"
+#include "cqhci.h"
 
 #define ESDHC_SYS_CTRL_DTOCV_MASK	0x0f
 #define	ESDHC_CTRL_D3CD			0x08
@@ -104,6 +105,9 @@
  */
 #define ESDHC_INT_VENDOR_SPEC_DMA_ERR	(1 << 28)
 
+/* the address offset of CQHCI */
+#define ESDHC_CQHCI_ADDR_OFFSET		0x100
+
 /*
  * The CMDTYPE of the CMD register (offset 0xE) should be set to
  * "11" when the STOP CMD12 is issued on imx53 to abort one
@@ -147,6 +151,8 @@
 #define ESDHC_FLAG_ERR010450		BIT(10)
 /* The IP supports HS400ES mode */
 #define ESDHC_FLAG_HS400_ES		BIT(11)
+/* The IP has Host Controller Interface for Command Queuing */
+#define ESDHC_FLAG_CQHCI		BIT(12)
 
 struct esdhc_soc_data {
 	u32 flags;
@@ -198,7 +204,8 @@ static const struct esdhc_soc_data usdhc_imx7d_data = {
 static struct esdhc_soc_data usdhc_imx8qxp_data = {
 	.flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_STD_TUNING
 			| ESDHC_FLAG_HAVE_CAP1 | ESDHC_FLAG_HS200
-			| ESDHC_FLAG_HS400 | ESDHC_FLAG_HS400_ES,
+			| ESDHC_FLAG_HS400 | ESDHC_FLAG_HS400_ES
+			| ESDHC_FLAG_CQHCI,
 };
 
 struct pltfm_imx_data {
@@ -1094,6 +1101,19 @@ static void esdhc_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
 			SDHCI_TIMEOUT_CONTROL);
 }
 
+static u32 esdhc_cqhci_irq(struct sdhci_host *host, u32 intmask)
+{
+	int cmd_error = 0;
+	int data_error = 0;
+
+	if (!sdhci_cqe_irq(host, intmask, &cmd_error, &data_error))
+		return intmask;
+
+	cqhci_irq(host->mmc, intmask, cmd_error, data_error);
+
+	return 0;
+}
+
 static struct sdhci_ops sdhci_esdhc_ops = {
 	.read_l = esdhc_readl_le,
 	.read_w = esdhc_readw_le,
@@ -1110,6 +1130,7 @@ static struct sdhci_ops sdhci_esdhc_ops = {
 	.set_bus_width = esdhc_pltfm_set_bus_width,
 	.set_uhs_signaling = esdhc_set_uhs_signaling,
 	.reset = esdhc_reset,
+	.irq = esdhc_cqhci_irq,
 };
 
 static const struct sdhci_pltfm_data sdhci_esdhc_imx_pdata = {
@@ -1185,6 +1206,55 @@ static void sdhci_esdhc_imx_hwinit(struct sdhci_host *host)
 	}
 }
 
+static void esdhc_cqe_enable(struct mmc_host *mmc)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	u32 reg;
+	u16 mode;
+	int count = 10;
+
+	/*
+	 * CQE gets stuck if it sees Buffer Read Enable bit set, which can be
+	 * the case after tuning, so ensure the buffer is drained.
+	 */
+	reg = sdhci_readl(host, SDHCI_PRESENT_STATE);
+	while (reg & SDHCI_DATA_AVAILABLE) {
+		sdhci_readl(host, SDHCI_BUFFER);
+		reg = sdhci_readl(host, SDHCI_PRESENT_STATE);
+		if (count-- == 0) {
+			dev_warn(mmc_dev(host->mmc),
+				"CQE may get stuck because the Buffer Read Enable bit is set\n");
+			break;
+		}
+		mdelay(1);
+	}
+
+	/*
+	 * Runtime resume will reset the entire host controller, which
+	 * will also clear the DMAEN/BCEN of register ESDHC_MIX_CTRL.
+	 * Here set DMAEN and BCEN when enable CMDQ.
+	 */
+	mode = sdhci_readw(host, SDHCI_TRANSFER_MODE);
+	if (host->flags & SDHCI_REQ_USE_DMA)
+		mode |= SDHCI_TRNS_DMA;
+	if (!(host->quirks2 & SDHCI_QUIRK2_SUPPORT_SINGLE))
+		mode |= SDHCI_TRNS_BLK_CNT_EN;
+	sdhci_writew(host, mode, SDHCI_TRANSFER_MODE);
+
+	sdhci_cqe_enable(mmc);
+}
+
+static void esdhc_sdhci_dumpregs(struct mmc_host *mmc)
+{
+	sdhci_dumpregs(mmc_priv(mmc));
+}
+
+static const struct cqhci_host_ops esdhc_cqhci_ops = {
+	.enable		= esdhc_cqe_enable,
+	.disable	= sdhci_cqe_disable,
+	.dumpregs	= esdhc_sdhci_dumpregs,
+};
+
 #ifdef CONFIG_OF
 static int
 sdhci_esdhc_imx_probe_dt(struct platform_device *pdev,
@@ -1316,6 +1386,7 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
 			of_match_device(imx_esdhc_dt_ids, &pdev->dev);
 	struct sdhci_pltfm_host *pltfm_host;
 	struct sdhci_host *host;
+	struct cqhci_host *cq_host;
 	int err;
 	struct pltfm_imx_data *imx_data;
 
@@ -1406,6 +1477,22 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
 					esdhc_hs400_enhanced_strobe;
 	}
 
+	if (imx_data->socdata->flags & ESDHC_FLAG_CQHCI) {
+		host->mmc->caps2 |= MMC_CAP2_CQE;
+		cq_host = devm_kzalloc(&pdev->dev, sizeof(*cq_host), GFP_KERNEL);
+		if (IS_ERR(cq_host)) {
+			err = PTR_ERR(cq_host);
+			goto disable_ahb_clk;
+		}
+
+		cq_host->mmio = host->ioaddr + ESDHC_CQHCI_ADDR_OFFSET;
+		cq_host->ops = &esdhc_cqhci_ops;
+
+		err = cqhci_init(cq_host, host->mmc, false);
+		if (err)
+			goto disable_ahb_clk;
+	}
+
 	if (of_id)
 		err = sdhci_esdhc_imx_probe_dt(pdev, host, imx_data);
 	else
@@ -1466,6 +1553,13 @@ static int sdhci_esdhc_imx_remove(struct platform_device *pdev)
 static int sdhci_esdhc_suspend(struct device *dev)
 {
 	struct sdhci_host *host = dev_get_drvdata(dev);
+	int ret;
+
+	if (host->mmc->caps2 & MMC_CAP2_CQE) {
+		ret = cqhci_suspend(host->mmc);
+		if (ret)
+			return ret;
+	}
 
 	if (host->tuning_mode != SDHCI_TUNING_MODE_3)
 		mmc_retune_needed(host->mmc);
@@ -1476,11 +1570,19 @@ static int sdhci_esdhc_suspend(struct device *dev)
 static int sdhci_esdhc_resume(struct device *dev)
 {
 	struct sdhci_host *host = dev_get_drvdata(dev);
+	int ret;
 
 	/* re-initialize hw state in case it's lost in low power mode */
 	sdhci_esdhc_imx_hwinit(host);
 
-	return sdhci_resume_host(host);
+	ret = sdhci_resume_host(host);
+	if (ret)
+		return ret;
+
+	if (host->mmc->caps2 & MMC_CAP2_CQE)
+		ret = cqhci_resume(host->mmc);
+
+	return ret;
 }
 #endif
 
@@ -1492,6 +1594,12 @@ static int sdhci_esdhc_runtime_suspend(struct device *dev)
 	struct pltfm_imx_data *imx_data = sdhci_pltfm_priv(pltfm_host);
 	int ret;
 
+	if (host->mmc->caps2 & MMC_CAP2_CQE) {
+		ret = cqhci_suspend(host->mmc);
+		if (ret)
+			return ret;
+	}
+
 	ret = sdhci_runtime_suspend_host(host);
 	if (ret)
 		return ret;
@@ -1535,7 +1643,10 @@ static int sdhci_esdhc_runtime_resume(struct device *dev)
 	if (err)
 		goto disable_ipg_clk;
 
-	return 0;
+	if (host->mmc->caps2 & MMC_CAP2_CQE)
+		err = cqhci_resume(host->mmc);
+
+	return err;
 
 disable_ipg_clk:
 	if (!sdhci_sdio_irq_enabled(host))