[PATCH] mmc: sdhci-tegra: Add required callbacks to set/clear CQE_EN bit

[Jon Hunter <jonathanh@nvidia.com>]

From: Aniruddha Tvs Rao <anrao@nvidia.com>

CMD8 is not supported with Command Queue Enabled. Add required callback
to clear CQE_EN and CQE_INTR fields in the host controller register
before sending CMD8. Add corresponding callback in the CQHCI resume path
to re-enable CQE_EN and CQE_INTR fields.

Reported-by: Kamal Mostafa <kamal@canonical.com>
Tested-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Aniruddha Tvs Rao <anrao@nvidia.com>
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
---
 drivers/mmc/host/sdhci-tegra.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index c61f797a853f..387ce9cdbd7c 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -119,6 +119,10 @@
 /* SDMMC CQE Base Address for Tegra Host Ver 4.1 and Higher */
 #define SDHCI_TEGRA_CQE_BASE_ADDR			0xF000
 
+#define SDHCI_TEGRA_CQE_TRNS_MODE	(SDHCI_TRNS_MULTI | \
+					 SDHCI_TRNS_BLK_CNT_EN | \
+					 SDHCI_TRNS_DMA)
+
 struct sdhci_tegra_soc_data {
 	const struct sdhci_pltfm_data *pdata;
 	u64 dma_mask;
@@ -1156,6 +1160,7 @@ static void tegra_sdhci_voltage_switch(struct sdhci_host *host)
 static void tegra_cqhci_writel(struct cqhci_host *cq_host, u32 val, int reg)
 {
 	struct mmc_host *mmc = cq_host->mmc;
+	struct sdhci_host *host = mmc_priv(mmc);
 	u8 ctrl;
 	ktime_t timeout;
 	bool timed_out;
@@ -1170,6 +1175,7 @@ static void tegra_cqhci_writel(struct cqhci_host *cq_host, u32 val, int reg)
 	 */
 	if (reg == CQHCI_CTL && !(val & CQHCI_HALT) &&
 	    cqhci_readl(cq_host, CQHCI_CTL) & CQHCI_HALT) {
+		sdhci_writew(host, SDHCI_TEGRA_CQE_TRNS_MODE, SDHCI_TRANSFER_MODE);
 		sdhci_cqe_enable(mmc);
 		writel(val, cq_host->mmio + reg);
 		timeout = ktime_add_us(ktime_get(), 50);
@@ -1205,6 +1211,7 @@ static void sdhci_tegra_update_dcmd_desc(struct mmc_host *mmc,
 static void sdhci_tegra_cqe_enable(struct mmc_host *mmc)
 {
 	struct cqhci_host *cq_host = mmc->cqe_private;
+	struct sdhci_host *host = mmc_priv(mmc);
 	u32 val;
 
 	/*
@@ -1218,6 +1225,7 @@ static void sdhci_tegra_cqe_enable(struct mmc_host *mmc)
 		if (val & CQHCI_ENABLE)
 			cqhci_writel(cq_host, (val & ~CQHCI_ENABLE),
 				     CQHCI_CFG);
+		sdhci_writew(host, SDHCI_TEGRA_CQE_TRNS_MODE, SDHCI_TRANSFER_MODE);
 		sdhci_cqe_enable(mmc);
 		if (val & CQHCI_ENABLE)
 			cqhci_writel(cq_host, val, CQHCI_CFG);
@@ -1281,12 +1289,36 @@ static void tegra_sdhci_set_timeout(struct sdhci_host *host,
 	__sdhci_set_timeout(host, cmd);
 }
 
+static void sdhci_tegra_cqe_pre_enable(struct mmc_host *mmc)
+{
+	struct cqhci_host *cq_host = mmc->cqe_private;
+	u32 reg;
+
+	reg = cqhci_readl(cq_host, CQHCI_CFG);
+	reg |= CQHCI_ENABLE;
+	cqhci_writel(cq_host, reg, CQHCI_CFG);
+}
+
+static void sdhci_tegra_cqe_post_disable(struct mmc_host *mmc)
+{
+	struct cqhci_host *cq_host = mmc->cqe_private;
+	struct sdhci_host *host = mmc_priv(mmc);
+	u32 reg;
+
+	reg = cqhci_readl(cq_host, CQHCI_CFG);
+	reg &= ~CQHCI_ENABLE;
+	cqhci_writel(cq_host, reg, CQHCI_CFG);
+	sdhci_writew(host, 0x0, SDHCI_TRANSFER_MODE);
+}
+
 static const struct cqhci_host_ops sdhci_tegra_cqhci_ops = {
 	.write_l    = tegra_cqhci_writel,
 	.enable	= sdhci_tegra_cqe_enable,
 	.disable = sdhci_cqe_disable,
 	.dumpregs = sdhci_tegra_dumpregs,
 	.update_dcmd_desc = sdhci_tegra_update_dcmd_desc,
+	.pre_enable = sdhci_tegra_cqe_pre_enable,
+	.post_disable = sdhci_tegra_cqe_post_disable,
 };
 
 static int tegra_sdhci_set_dma_mask(struct sdhci_host *host)
-- 
2.25.1