[PATCH v2 3/3] mmc: sdio: mediatek: Support SDIO feature

Yong Mao yong.mao at mediatek.com
Tue Apr 18 03:13:11 PDT 2017


From: yong mao <yong.mao at mediatek.com>

1. Add irqlock to protect accessing the shared register
2. Implement enable_sdio_irq interface
3. Add msdc_recheck_sdio_irq mechanism to make sure all interrupts
   can be processed immediately

Signed-off-by: Yong Mao <yong.mao at mediatek.com>
Signed-off-by: Chaotian Jing <chaotian.jing at mediatek.com>
---
 drivers/mmc/host/mtk-sd.c |  182 +++++++++++++++++++++++++++++++++++----------
 1 file changed, 143 insertions(+), 39 deletions(-)

diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 07f3236..fdae197 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -118,6 +118,7 @@
 #define MSDC_PS_CDSTS           (0x1 << 1)	/* R  */
 #define MSDC_PS_CDDEBOUNCE      (0xf << 12)	/* RW */
 #define MSDC_PS_DAT             (0xff << 16)	/* R  */
+#define MSDC_PS_DATA1           (0x1 << 17)	/* R  */
 #define MSDC_PS_CMD             (0x1 << 24)	/* R  */
 #define MSDC_PS_WP              (0x1 << 31)	/* R  */
 
@@ -312,6 +313,7 @@ struct msdc_host {
 	int cmd_rsp;
 
 	spinlock_t lock;
+	spinlock_t irqlock;    /* irq lock */
 	struct mmc_request *mrq;
 	struct mmc_command *cmd;
 	struct mmc_data *data;
@@ -330,12 +332,14 @@ struct msdc_host {
 	struct pinctrl_state *pins_uhs;
 	struct delayed_work req_timeout;
 	int irq;		/* host interrupt */
+	bool irq_thread_alive;
 
 	struct clk *src_clk;	/* msdc source clock */
 	struct clk *h_clk;      /* msdc h_clk */
 	u32 mclk;		/* mmc subsystem clock frequency */
 	u32 src_clk_freq;	/* source clock frequency */
 	u32 sclk;		/* SD/MS bus clock frequency */
+	bool clock_on;
 	unsigned char timing;
 	bool vqmmc_enabled;
 	u32 hs400_ds_delay;
@@ -343,6 +347,7 @@ struct msdc_host {
 	u32 hs400_cmd_int_delay; /* cmd internal delay for HS400 */
 	bool hs400_cmd_resp_sel_rising;
 				 /* cmd response sample selection for HS400 */
+	u32 clk_pad_delay;
 	bool hs400_mode;	/* current eMMC will run at hs400 mode */
 	struct msdc_save_para save_para; /* used when gate HCLK */
 	struct msdc_tune_para def_tune_para; /* default tune setting */
@@ -399,6 +404,7 @@ static void msdc_reset_hw(struct msdc_host *host)
 
 static void msdc_cmd_next(struct msdc_host *host,
 		struct mmc_request *mrq, struct mmc_command *cmd);
+static void msdc_recheck_sdio_irq(struct msdc_host *host);
 
 static const u32 cmd_ints_mask = MSDC_INTEN_CMDRDY | MSDC_INTEN_RSPCRCERR |
 			MSDC_INTEN_CMDTMO | MSDC_INTEN_ACMDRDY |
@@ -525,6 +531,7 @@ static void msdc_gate_clock(struct msdc_host *host)
 {
 	clk_disable_unprepare(host->src_clk);
 	clk_disable_unprepare(host->h_clk);
+	host->clock_on = false;
 }
 
 static void msdc_ungate_clock(struct msdc_host *host)
@@ -533,6 +540,7 @@ static void msdc_ungate_clock(struct msdc_host *host)
 	clk_prepare_enable(host->src_clk);
 	while (!(readl(host->base + MSDC_CFG) & MSDC_CFG_CKSTB))
 		cpu_relax();
+	host->clock_on = true;
 }
 
 static void msdc_set_mclk(struct msdc_host *host, unsigned char timing, u32 hz)
@@ -541,6 +549,7 @@ static void msdc_set_mclk(struct msdc_host *host, unsigned char timing, u32 hz)
 	u32 flags;
 	u32 div;
 	u32 sclk;
+	unsigned long irq_flags;
 
 	if (!hz) {
 		dev_dbg(host->dev, "set mclk to 0\n");
@@ -549,8 +558,11 @@ static void msdc_set_mclk(struct msdc_host *host, unsigned char timing, u32 hz)
 		return;
 	}
 
+	spin_lock_irqsave(&host->irqlock, irq_flags);
 	flags = readl(host->base + MSDC_INTEN);
 	sdr_clr_bits(host->base + MSDC_INTEN, flags);
+	spin_unlock_irqrestore(&host->irqlock, irq_flags);
+
 	sdr_clr_bits(host->base + MSDC_CFG, MSDC_CFG_HS400_CK_MODE);
 	if (timing == MMC_TIMING_UHS_DDR50 ||
 	    timing == MMC_TIMING_MMC_DDR52 ||
@@ -600,7 +612,10 @@ static void msdc_set_mclk(struct msdc_host *host, unsigned char timing, u32 hz)
 	host->timing = timing;
 	/* need because clk changed. */
 	msdc_set_timeout(host, host->timeout_ns, host->timeout_clks);
+
+	spin_lock_irqsave(&host->irqlock, irq_flags);
 	sdr_set_bits(host->base + MSDC_INTEN, flags);
+	spin_unlock_irqrestore(&host->irqlock, irq_flags);
 
 	/*
 	 * mmc_select_hs400() will drop to 50Mhz and High speed mode,
@@ -708,6 +723,7 @@ static inline u32 msdc_cmd_prepare_raw_cmd(struct msdc_host *host,
 static void msdc_start_data(struct msdc_host *host, struct mmc_request *mrq,
 			    struct mmc_command *cmd, struct mmc_data *data)
 {
+	unsigned long flags;
 	bool read;
 
 	WARN_ON(host->data);
@@ -716,8 +732,12 @@ static void msdc_start_data(struct msdc_host *host, struct mmc_request *mrq,
 
 	mod_delayed_work(system_wq, &host->req_timeout, DAT_TIMEOUT);
 	msdc_dma_setup(host, &host->dma, data);
+
+	spin_lock_irqsave(&host->irqlock, flags);
 	sdr_set_bits(host->base + MSDC_INTEN, data_ints_mask);
 	sdr_set_field(host->base + MSDC_DMA_CTRL, MSDC_DMA_CTRL_START, 1);
+	spin_unlock_irqrestore(&host->irqlock, flags);
+
 	dev_dbg(host->dev, "DMA start\n");
 	dev_dbg(host->dev, "%s: cmd=%d DMA data: %d blocks; read=%d\n",
 			__func__, cmd->opcode, data->blocks, read);
@@ -774,6 +794,8 @@ static void msdc_request_done(struct msdc_host *host, struct mmc_request *mrq)
 	if (mrq->data)
 		msdc_unprepare_data(host, mrq);
 	mmc_request_done(host->mmc, mrq);
+
+	msdc_recheck_sdio_irq(host);
 }
 
 /* returns true if command is fully handled; returns false otherwise */
@@ -797,15 +819,17 @@ static bool msdc_cmd_done(struct msdc_host *host, int events,
 					| MSDC_INT_CMDTMO)))
 		return done;
 
-	spin_lock_irqsave(&host->lock, flags);
 	done = !host->cmd;
+	spin_lock_irqsave(&host->lock, flags);
 	host->cmd = NULL;
 	spin_unlock_irqrestore(&host->lock, flags);
 
 	if (done)
 		return true;
 
+	spin_lock_irqsave(&host->irqlock, flags);
 	sdr_clr_bits(host->base + MSDC_INTEN, cmd_ints_mask);
+	spin_unlock_irqrestore(&host->irqlock, flags);
 
 	if (cmd->flags & MMC_RSP_PRESENT) {
 		if (cmd->flags & MMC_RSP_136) {
@@ -883,6 +907,7 @@ static inline bool msdc_cmd_is_ready(struct msdc_host *host,
 static void msdc_start_command(struct msdc_host *host,
 		struct mmc_request *mrq, struct mmc_command *cmd)
 {
+	unsigned long flags;
 	u32 rawcmd;
 
 	WARN_ON(host->cmd);
@@ -901,7 +926,10 @@ static void msdc_start_command(struct msdc_host *host,
 	rawcmd = msdc_cmd_prepare_raw_cmd(host, mrq, cmd);
 	mod_delayed_work(system_wq, &host->req_timeout, DAT_TIMEOUT);
 
+	spin_lock_irqsave(&host->irqlock, flags);
 	sdr_set_bits(host->base + MSDC_INTEN, cmd_ints_mask);
+	spin_unlock_irqrestore(&host->irqlock, flags);
+
 	writel(cmd->arg, host->base + SDC_ARG);
 	writel(rawcmd, host->base + SDC_CMD);
 }
@@ -993,8 +1021,8 @@ static bool msdc_data_xfer_done(struct msdc_host *host, u32 events,
 	     | MSDC_INT_DMA_BDCSERR | MSDC_INT_DMA_GPDCSERR
 	     | MSDC_INT_DMA_PROTECT);
 
-	spin_lock_irqsave(&host->lock, flags);
 	done = !host->data;
+	spin_lock_irqsave(&host->lock, flags);
 	if (check_data)
 		host->data = NULL;
 	spin_unlock_irqrestore(&host->lock, flags);
@@ -1009,7 +1037,11 @@ static bool msdc_data_xfer_done(struct msdc_host *host, u32 events,
 				1);
 		while (readl(host->base + MSDC_DMA_CFG) & MSDC_DMA_CFG_STS)
 			cpu_relax();
+
+		spin_lock_irqsave(&host->irqlock, flags);
 		sdr_clr_bits(host->base + MSDC_INTEN, data_ints_mask);
+		spin_unlock_irqrestore(&host->irqlock, flags);
+
 		dev_dbg(host->dev, "DMA stop\n");
 
 		if ((events & MSDC_INT_XFER_COMPL) && (!stop || !stop->error)) {
@@ -1123,44 +1155,47 @@ static void msdc_request_timeout(struct work_struct *work)
 
 static irqreturn_t msdc_irq(int irq, void *dev_id)
 {
+	unsigned long flags;
 	struct msdc_host *host = (struct msdc_host *) dev_id;
+	struct mmc_request *mrq;
+	struct mmc_command *cmd;
+	struct mmc_data *data;
+	u32 events, event_mask;
+
+	spin_lock_irqsave(&host->irqlock, flags);
+	events = readl(host->base + MSDC_INT);
+	event_mask = readl(host->base + MSDC_INTEN);
+	/* clear interrupts */
+	writel(events & event_mask, host->base + MSDC_INT);
+
+	mrq = host->mrq;
+	cmd = host->cmd;
+	data = host->data;
+	spin_unlock_irqrestore(&host->irqlock, flags);
+
+	if ((events & event_mask) & MSDC_INT_SDIOIRQ) {
+		mmc_signal_sdio_irq(host->mmc);
+		if (!mrq)
+			return IRQ_HANDLED;
+	}
 
-	while (true) {
-		unsigned long flags;
-		struct mmc_request *mrq;
-		struct mmc_command *cmd;
-		struct mmc_data *data;
-		u32 events, event_mask;
-
-		spin_lock_irqsave(&host->lock, flags);
-		events = readl(host->base + MSDC_INT);
-		event_mask = readl(host->base + MSDC_INTEN);
-		/* clear interrupts */
-		writel(events & event_mask, host->base + MSDC_INT);
-
-		mrq = host->mrq;
-		cmd = host->cmd;
-		data = host->data;
-		spin_unlock_irqrestore(&host->lock, flags);
-
-		if (!(events & event_mask))
-			break;
+	if (!(events & (event_mask & ~MSDC_INT_SDIOIRQ)))
+		return IRQ_HANDLED;
 
-		if (!mrq) {
-			dev_err(host->dev,
-				"%s: MRQ=NULL; events=%08X; event_mask=%08X\n",
-				__func__, events, event_mask);
-			WARN_ON(1);
-			break;
-		}
+	if (!mrq) {
+		dev_err(host->dev,
+			"%s: MRQ=NULL; events=%08X; event_mask=%08X\n",
+			__func__, events, event_mask);
+		WARN_ON(1);
+		return IRQ_HANDLED;
+	}
 
-		dev_dbg(host->dev, "%s: events=%08X\n", __func__, events);
+	dev_dbg(host->dev, "%s: events=%08X\n", __func__, events);
 
-		if (cmd)
-			msdc_cmd_done(host, events, mrq, cmd);
-		else if (data)
-			msdc_data_xfer_done(host, events, mrq, data);
-	}
+	if (cmd)
+		msdc_cmd_done(host, events, mrq, cmd);
+	else if (data)
+		msdc_data_xfer_done(host, events, mrq, data);
 
 	return IRQ_HANDLED;
 }
@@ -1168,6 +1203,7 @@ static irqreturn_t msdc_irq(int irq, void *dev_id)
 static void msdc_init_hw(struct msdc_host *host)
 {
 	u32 val;
+	unsigned long flags;
 
 	/* Configure to MMC/SD mode, clock free running */
 	sdr_set_bits(host->base + MSDC_CFG, MSDC_CFG_MODE | MSDC_CFG_CKPDN);
@@ -1179,11 +1215,14 @@ static void msdc_init_hw(struct msdc_host *host)
 	sdr_clr_bits(host->base + MSDC_PS, MSDC_PS_CDEN);
 
 	/* Disable and clear all interrupts */
+	spin_lock_irqsave(&host->irqlock, flags);
 	writel(0, host->base + MSDC_INTEN);
 	val = readl(host->base + MSDC_INT);
 	writel(val, host->base + MSDC_INT);
+	spin_unlock_irqrestore(&host->irqlock, flags);
 
-	writel(0, host->base + MSDC_PAD_TUNE);
+	sdr_set_field(host->base + MSDC_PAD_TUNE,
+		      MSDC_PAD_TUNE_CLKTDLY, host->clk_pad_delay);
 	writel(0, host->base + MSDC_IOCON);
 	sdr_set_field(host->base + MSDC_IOCON, MSDC_IOCON_DDLSEL, 0);
 	writel(0x403c0046, host->base + MSDC_PATCH_BIT);
@@ -1196,9 +1235,11 @@ static void msdc_init_hw(struct msdc_host *host)
 	 */
 	sdr_set_bits(host->base + SDC_CFG, SDC_CFG_SDIO);
 
-	/* disable detect SDIO device interrupt function */
-	sdr_clr_bits(host->base + SDC_CFG, SDC_CFG_SDIOIDE);
-
+	if (host->mmc->caps & MMC_CAP_SDIO_IRQ)
+		sdr_set_bits(host->base + SDC_CFG, SDC_CFG_SDIOIDE);
+	else
+		/* disable detect SDIO device interrupt function */
+		sdr_clr_bits(host->base + SDC_CFG, SDC_CFG_SDIOIDE);
 	/* Configure to default data timeout */
 	sdr_set_field(host->base + SDC_CFG, SDC_CFG_DTOC, 3);
 
@@ -1210,11 +1251,15 @@ static void msdc_init_hw(struct msdc_host *host)
 static void msdc_deinit_hw(struct msdc_host *host)
 {
 	u32 val;
+	unsigned long flags;
+
 	/* Disable and clear all interrupts */
+	spin_lock_irqsave(&host->irqlock, flags);
 	writel(0, host->base + MSDC_INTEN);
 
 	val = readl(host->base + MSDC_INT);
 	writel(val, host->base + MSDC_INT);
+	spin_unlock_irqrestore(&host->irqlock, flags);
 }
 
 /* init gpd and bd list in msdc_drv_probe */
@@ -1582,6 +1627,48 @@ static void msdc_hw_reset(struct mmc_host *mmc)
 	sdr_clr_bits(host->base + EMMC_IOCON, 1);
 }
 
+/**
+ * msdc_recheck_sdio_irq - recheck whether the SDIO IRQ is lost
+ * @host: The host to check.
+ *
+ * Host controller may lost interrupt in some special case.
+ * Add sdio IRQ recheck mechanism to make sure all interrupts
+ * can be processed immediately
+ */
+static void msdc_recheck_sdio_irq(struct msdc_host *host)
+{
+	u32 reg_int, reg_ps;
+
+	if (host->clock_on && (host->mmc->caps & MMC_CAP_SDIO_IRQ) &&
+	    host->irq_thread_alive) {
+		reg_int = readl(host->base + MSDC_INT);
+		reg_ps  = readl(host->base + MSDC_PS);
+		if (!((reg_int & MSDC_INT_SDIOIRQ) ||
+		      (reg_ps & MSDC_PS_DATA1)))
+			mmc_signal_sdio_irq(host->mmc);
+	}
+}
+
+static void msdc_enable_sdio_irq(struct mmc_host *mmc, int enable)
+{
+	unsigned long flags;
+	struct msdc_host *host = mmc_priv(mmc);
+
+	host->irq_thread_alive = true;
+	if (enable) {
+		msdc_recheck_sdio_irq(host);
+
+		spin_lock_irqsave(&host->irqlock, flags);
+		sdr_set_bits(host->base + SDC_CFG, SDC_CFG_SDIOIDE);
+		sdr_set_bits(host->base + MSDC_INTEN, MSDC_INTEN_SDIOIRQ);
+		spin_unlock_irqrestore(&host->irqlock, flags);
+	} else {
+		spin_lock_irqsave(&host->irqlock, flags);
+		sdr_clr_bits(host->base + MSDC_INTEN, MSDC_INTEN_SDIOIRQ);
+		spin_unlock_irqrestore(&host->irqlock, flags);
+	}
+}
+
 static struct mmc_host_ops mt_msdc_ops = {
 	.post_req = msdc_post_req,
 	.pre_req = msdc_pre_req,
@@ -1593,6 +1680,7 @@ static void msdc_hw_reset(struct mmc_host *mmc)
 	.execute_tuning = msdc_execute_tuning,
 	.prepare_hs400_tuning = msdc_prepare_hs400_tuning,
 	.hw_reset = msdc_hw_reset,
+	.enable_sdio_irq = msdc_enable_sdio_irq,
 };
 
 static void msdc_of_property_parse(struct platform_device *pdev,
@@ -1612,6 +1700,9 @@ static void msdc_of_property_parse(struct platform_device *pdev,
 		host->hs400_cmd_resp_sel_rising = true;
 	else
 		host->hs400_cmd_resp_sel_rising = false;
+
+	of_property_read_u32(pdev->dev.of_node, "mediatek,clk-pad-delay",
+			     &host->clk_pad_delay);
 }
 
 static int msdc_drv_probe(struct platform_device *pdev)
@@ -1705,6 +1796,7 @@ static int msdc_drv_probe(struct platform_device *pdev)
 	mmc_dev(mmc)->dma_mask = &host->dma_mask;
 
 	host->timeout_clks = 3 * 1048576;
+	host->irq_thread_alive = false;
 	host->dma.gpd = dma_alloc_coherent(&pdev->dev,
 				2 * sizeof(struct mt_gpdma_desc),
 				&host->dma.gpd_addr, GFP_KERNEL);
@@ -1718,6 +1810,7 @@ static int msdc_drv_probe(struct platform_device *pdev)
 	msdc_init_gpd_bd(host, &host->dma);
 	INIT_DELAYED_WORK(&host->req_timeout, msdc_request_timeout);
 	spin_lock_init(&host->lock);
+	spin_lock_init(&host->irqlock);
 
 	platform_set_drvdata(pdev, mmc);
 	msdc_ungate_clock(host);
@@ -1732,6 +1825,10 @@ static int msdc_drv_probe(struct platform_device *pdev)
 	pm_runtime_set_autosuspend_delay(host->dev, MTK_MMC_AUTOSUSPEND_DELAY);
 	pm_runtime_use_autosuspend(host->dev);
 	pm_runtime_enable(host->dev);
+
+	/* In SDIO irq mode, DATA1 slways need to be detected */
+	if (host->mmc->caps & MMC_CAP_SDIO_IRQ)
+		pm_runtime_get_sync(host->dev);
 	ret = mmc_add_host(mmc);
 
 	if (ret)
@@ -1821,6 +1918,10 @@ static int msdc_runtime_suspend(struct device *dev)
 
 	msdc_save_reg(host);
 	msdc_gate_clock(host);
+	if (host->mmc->caps & MMC_CAP_SDIO_IRQ) {
+		pm_runtime_mark_last_busy(dev);
+		pm_runtime_put_autosuspend(dev);
+	}
 	return 0;
 }
 
@@ -1829,6 +1930,9 @@ static int msdc_runtime_resume(struct device *dev)
 	struct mmc_host *mmc = dev_get_drvdata(dev);
 	struct msdc_host *host = mmc_priv(mmc);
 
+	/* In SDIO irq mode, DATA1 slways need to be detected */
+	if (host->mmc->caps & MMC_CAP_SDIO_IRQ)
+		pm_runtime_get_sync(host->dev);
 	msdc_ungate_clock(host);
 	msdc_restore_reg(host);
 	return 0;
-- 
1.7.9.5




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