[PATCH v5 1/3] mmc: omap_hsmmc: Enable SDIO IRQ.

[Andreas Fenkart <afenkart@gmail.com>]

For now, only support SDIO interrupt if we are booted with
DT. This is because some platforms need special quirks. And
we don't want to add new legacy mux platform init code
callbacks any longer as we are moving to DT based booting
anyways.

Signed-off-by: Andreas Fenkart <afenkart@gmail.com>
---
 drivers/mmc/host/omap_hsmmc.c          |  109 ++++++++++++++++++++++++++++----
 include/linux/platform_data/mmc-omap.h |    1 +
 2 files changed, 97 insertions(+), 13 deletions(-)

diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 8be5c9f..c197028 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -131,6 +131,7 @@ static void apply_clk_hack(struct device *dev)
 #define TC_EN			(1 << 1)
 #define BWR_EN			(1 << 4)
 #define BRR_EN			(1 << 5)
+#define CIRQ_EN			(1 << 8)
 #define ERR_EN			(1 << 15)
 #define CTO_EN			(1 << 16)
 #define CCRC_EN			(1 << 17)
@@ -215,6 +216,9 @@ struct omap_hsmmc_host {
 	int			reqs_blocked;
 	int			use_reg;
 	int			req_in_progress;
+	int                     flags;
+#define HSMMC_SDIO_IRQ_ENABLED	(1 << 0)        /* SDIO irq enabled */
+
 	struct omap_hsmmc_next	next_data;
 	struct	omap_mmc_platform_data	*pdata;
 };
@@ -495,27 +499,40 @@ static void omap_hsmmc_stop_clock(struct omap_hsmmc_host *host)
 static void omap_hsmmc_enable_irq(struct omap_hsmmc_host *host,
 				  struct mmc_command *cmd)
 {
-	unsigned int irq_mask;
+	u32 irq_mask = INT_EN_MASK;
+	unsigned long flags;
 
 	if (host->use_dma)
-		irq_mask = INT_EN_MASK & ~(BRR_EN | BWR_EN);
-	else
-		irq_mask = INT_EN_MASK;
+		irq_mask &= ~(BRR_EN | BWR_EN);
 
 	/* Disable timeout for erases */
 	if (cmd->opcode == MMC_ERASE)
 		irq_mask &= ~DTO_EN;
 
+	spin_lock_irqsave(&host->irq_lock, flags);
 	OMAP_HSMMC_WRITE(host->base, STAT, STAT_CLEAR);
 	OMAP_HSMMC_WRITE(host->base, ISE, irq_mask);
+
+	/* latch pending CIRQ, but don't signal */
+	if (host->flags & HSMMC_SDIO_IRQ_ENABLED)
+		irq_mask |= CIRQ_EN;
 	OMAP_HSMMC_WRITE(host->base, IE, irq_mask);
+	spin_unlock_irqrestore(&host->irq_lock, flags);
 }
 
 static void omap_hsmmc_disable_irq(struct omap_hsmmc_host *host)
 {
-	OMAP_HSMMC_WRITE(host->base, ISE, 0);
-	OMAP_HSMMC_WRITE(host->base, IE, 0);
+	u32 irq_mask = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&host->irq_lock, flags);
+	/* no transfer running, need to signal cirq if enabled */
+	if (host->flags & HSMMC_SDIO_IRQ_ENABLED)
+		irq_mask |= CIRQ_EN;
+	OMAP_HSMMC_WRITE(host->base, ISE, irq_mask);
+	OMAP_HSMMC_WRITE(host->base, IE, irq_mask);
 	OMAP_HSMMC_WRITE(host->base, STAT, STAT_CLEAR);
+	spin_unlock_irqrestore(&host->irq_lock, flags);
 }
 
 /* Calculate divisor for the given clock frequency */
@@ -1078,8 +1095,12 @@ static irqreturn_t omap_hsmmc_irq(int irq, void *dev_id)
 	int status;
 
 	status = OMAP_HSMMC_READ(host->base, STAT);
-	while (status & INT_EN_MASK && host->req_in_progress) {
-		omap_hsmmc_do_irq(host, status);
+	while (status & (INT_EN_MASK | CIRQ_EN)) {
+		if (host->req_in_progress)
+			omap_hsmmc_do_irq(host, status);
+
+		if (status & CIRQ_EN)
+			mmc_signal_sdio_irq(host->mmc);
 
 		/* Flush posted write */
 		status = OMAP_HSMMC_READ(host->base, STAT);
@@ -1591,6 +1612,37 @@ static void omap_hsmmc_init_card(struct mmc_host *mmc, struct mmc_card *card)
 		mmc_slot(host).init_card(card);
 }
 
+static void omap_hsmmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
+{
+	struct omap_hsmmc_host *host = mmc_priv(mmc);
+	u32 irq_mask;
+	unsigned long flags;
+
+	spin_lock_irqsave(&host->irq_lock, flags);
+
+	irq_mask = OMAP_HSMMC_READ(host->base, ISE);
+	if (enable) {
+		host->flags |= HSMMC_SDIO_IRQ_ENABLED;
+		irq_mask |= CIRQ_EN;
+	} else {
+		host->flags &= ~HSMMC_SDIO_IRQ_ENABLED;
+		irq_mask &= ~CIRQ_EN;
+	}
+	OMAP_HSMMC_WRITE(host->base, IE, irq_mask);
+
+	/*
+	 * if enable, piggy back detection on current request
+	 * but always disable immediately
+	 */
+	if (!host->req_in_progress || !enable)
+		OMAP_HSMMC_WRITE(host->base, ISE, irq_mask);
+
+	/* flush posted write */
+	OMAP_HSMMC_READ(host->base, IE);
+
+	spin_unlock_irqrestore(&host->irq_lock, flags);
+}
+
 static void omap_hsmmc_conf_bus_power(struct omap_hsmmc_host *host)
 {
 	u32 hctl, capa, value;
@@ -1643,7 +1695,7 @@ static const struct mmc_host_ops omap_hsmmc_ops = {
 	.get_cd = omap_hsmmc_get_cd,
 	.get_ro = omap_hsmmc_get_ro,
 	.init_card = omap_hsmmc_init_card,
-	/* NYET -- enable_sdio_irq */
+	.enable_sdio_irq = omap_hsmmc_enable_sdio_irq,
 };
 
 #ifdef CONFIG_DEBUG_FS
@@ -1705,7 +1757,18 @@ static void omap_hsmmc_debugfs(struct mmc_host *mmc)
 #endif
 
 #ifdef CONFIG_OF
-static u16 omap4_reg_offset = 0x100;
+struct of_data {
+	u16 offset;
+	int flags;
+};
+
+static struct of_data omap4_data = {
+	.offset	= 0x100,
+};
+static struct of_data am33xx_data = {
+	.offset	= 0x100,
+	.flags	= OMAP_HSMMC_SWAKEUP_MISSING,
+};
 
 static const struct of_device_id omap_mmc_of_match[] = {
 	{
@@ -1716,7 +1779,11 @@ static const struct of_device_id omap_mmc_of_match[] = {
 	},
 	{
 		.compatible = "ti,omap4-hsmmc",
-		.data = &omap4_reg_offset,
+		.data = &omap4_data,
+	},
+	{
+		.compatible = "ti,am33xx-hsmmc",
+		.data = &am33xx_data,
 	},
 	{},
 };
@@ -1801,8 +1868,9 @@ static int omap_hsmmc_probe(struct platform_device *pdev)
 			return PTR_ERR(pdata);
 
 		if (match->data) {
-			const u16 *offsetp = match->data;
-			pdata->reg_offset = *offsetp;
+			const struct of_data *d = match->data;
+			pdata->reg_offset = d->offset;
+			pdata->controller_flags |= d->flags;
 		}
 	}
 
@@ -2020,6 +2088,21 @@ static int omap_hsmmc_probe(struct platform_device *pdev)
 		dev_warn(&pdev->dev,
 			"pins are not configured from the driver\n");
 
+	/*
+	 * For now, only support SDIO interrupt if we are booted with
+	 * DT. This is because some platforms need special quirks. And
+	 * we don't want to add new legacy mux platform init code
+	 * callbacks any longer as we are moving to DT based booting
+	 * anyways.
+	 */
+	if (pdev->dev.of_node) {
+		mmc->caps |= MMC_CAP_SDIO_IRQ;
+		if (pdata->controller_flags & OMAP_HSMMC_SWAKEUP_MISSING) {
+			/* no wakeup from deeper power states, use polling */
+			mmc->caps &= ~MMC_CAP_SDIO_IRQ;
+		}
+	}
+
 	omap_hsmmc_protect_card(host);
 
 	mmc_add_host(mmc);
diff --git a/include/linux/platform_data/mmc-omap.h b/include/linux/platform_data/mmc-omap.h
index 2bf1b30..51e70cf 100644
--- a/include/linux/platform_data/mmc-omap.h
+++ b/include/linux/platform_data/mmc-omap.h
@@ -28,6 +28,7 @@
  */
 #define OMAP_HSMMC_SUPPORTS_DUAL_VOLT		BIT(0)
 #define OMAP_HSMMC_BROKEN_MULTIBLOCK_READ	BIT(1)
+#define OMAP_HSMMC_SWAKEUP_MISSING		BIT(2)
 
 struct mmc_card;
 
-- 
1.7.10.4