[PATCH V1] mmc: sdhci-msm: Add CQHCI support for sdhci-msm

[Veerabhadrarao Badiganti <vbadigan@codeaurora.org>]

From: Ritesh Harjani <riteshh@codeaurora.org>

This adds CQHCI support for sdhci-msm platforms.

Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org>
Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>

---
This patch is based on RFC patch
https://lkml.org/lkml/2017/8/30/313

Changes since RFC:
	- Updated settings so that TDLBA won't get reset when
	  CQE is enabled.
	- Removed new compatible string and moved to supports-cqe
	  dt flag to identify CQE support.
	- Incorporated review comments.

Tested on: qcs404, sc7180
---
 drivers/mmc/host/sdhci-msm.c | 115 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 114 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index 3d0bb5e..a4e3507 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -15,6 +15,7 @@
 #include <linux/regulator/consumer.h>
 
 #include "sdhci-pltfm.h"
+#include "cqhci.h"
 
 #define CORE_MCI_VERSION		0x50
 #define CORE_VERSION_MAJOR_SHIFT	28
@@ -122,6 +123,10 @@
 #define msm_host_writel(msm_host, val, host, offset) \
 	msm_host->var_ops->msm_writel_relaxed(val, host, offset)
 
+/* CQHCI vendor specific registers */
+#define CQHCI_VENDOR_CFG1	0xA00
+#define DISABLE_RST_ON_CMDQ_EN	(0x3 << 13)
+
 struct sdhci_msm_offset {
 	u32 core_hc_mode;
 	u32 core_mci_data_cnt;
@@ -1567,6 +1572,109 @@ static void sdhci_msm_set_clock(struct sdhci_host *host, unsigned int clock)
 	__sdhci_msm_set_clock(host, clock);
 }
 
+/*****************************************************************************\
+ *                                                                           *
+ * MSM Command Queue Engine (CQE)                                            *
+ *                                                                           *
+\*****************************************************************************/
+
+static u32 sdhci_msm_cqe_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;
+}
+
+void sdhci_msm_cqe_disable(struct mmc_host *mmc, bool recovery)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	unsigned long flags;
+	u32 ctrl;
+
+	/*
+	 * When CQE is halted, the legacy SDHCI path operates only
+	 * on 128bit descriptors in 64bit mode.
+	 */
+	if (host->flags & SDHCI_USE_64_BIT_DMA)
+		host->desc_sz = 16;
+
+	spin_lock_irqsave(&host->lock, flags);
+
+	/*
+	 * During CQE operation command complete bit gets latched.
+	 * So s/w should clear command complete interrupt status when CQE is
+	 * halted. Otherwise unexpected SDCHI legacy interrupt gets
+	 * triggered when CQE is halted.
+	 */
+	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);
+}
+
+static const struct cqhci_host_ops sdhci_msm_cqhci_ops = {
+	.enable		= sdhci_cqe_enable,
+	.disable	= sdhci_msm_cqe_disable,
+};
+
+static int sdhci_msm_cqe_add_host(struct sdhci_host *host,
+				struct platform_device *pdev)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
+	struct cqhci_host *cq_host;
+	bool dma64;
+	int ret;
+
+	ret = sdhci_setup_host(host);
+	if (ret)
+		return ret;
+
+	cq_host = cqhci_pltfm_init(pdev);
+	if (IS_ERR(cq_host)) {
+		ret = PTR_ERR(cq_host);
+		dev_err(&pdev->dev, "cqhci-pltfm init: failed: %d\n", ret);
+		goto cleanup;
+	}
+
+	msm_host->mmc->caps2 |= MMC_CAP2_CQE | MMC_CAP2_CQE_DCMD;
+	cq_host->ops = &sdhci_msm_cqhci_ops;
+
+	dma64 = host->flags & SDHCI_USE_64_BIT_DMA;
+
+	ret = cqhci_init(cq_host, host->mmc, dma64);
+	if (ret) {
+		dev_err(&pdev->dev, "%s: CQE init: failed (%d)\n",
+				mmc_hostname(host->mmc), ret);
+		goto cleanup;
+	}
+
+	/* Disable cqe reset due to cqe enable signal */
+	cqhci_writel(cq_host, cqhci_readl(cq_host, CQHCI_VENDOR_CFG1) |
+		       DISABLE_RST_ON_CMDQ_EN, CQHCI_VENDOR_CFG1);
+
+	ret = __sdhci_add_host(host);
+	if (ret)
+		goto cleanup;
+
+	dev_info(&pdev->dev, "%s: CQE init: success\n",
+			mmc_hostname(host->mmc));
+	return ret;
+
+cleanup:
+	sdhci_cleanup_host(host);
+	return ret;
+}
+
 /*
  * Platform specific register write functions. This is so that, if any
  * register write needs to be followed up by platform specific actions,
@@ -1731,6 +1839,7 @@ static void sdhci_msm_set_regulator_caps(struct sdhci_msm_host *msm_host)
 	.set_uhs_signaling = sdhci_msm_set_uhs_signaling,
 	.write_w = sdhci_msm_writew,
 	.write_b = sdhci_msm_writeb,
+	.irq	= sdhci_msm_cqe_irq,
 };
 
 static const struct sdhci_pltfm_data sdhci_msm_pdata = {
@@ -1754,6 +1863,7 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 	u8 core_major;
 	const struct sdhci_msm_offset *msm_offset;
 	const struct sdhci_msm_variant_info *var_info;
+	struct device_node *node = pdev->dev.of_node;
 
 	host = sdhci_pltfm_init(pdev, &sdhci_msm_pdata, sizeof(*msm_host));
 	if (IS_ERR(host))
@@ -1952,7 +2062,10 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 	pm_runtime_use_autosuspend(&pdev->dev);
 
 	host->mmc_host_ops.execute_tuning = sdhci_msm_execute_tuning;
-	ret = sdhci_add_host(host);
+	if (of_property_read_bool(node, "supports-cqe"))
+		ret = sdhci_msm_cqe_add_host(host, pdev);
+	else
+		ret = sdhci_add_host(host);
 	if (ret)
 		goto pm_runtime_disable;
 	sdhci_msm_set_regulator_caps(msm_host);
-- 
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