OMAP2/3 MMC: initial conversion to runtime PM

Convert the HSMMC driver to use the runtime PM layer.  A notable
    aspect of this is that the use of the dev_attr data from the
    omap_hwmod allows the redaction of all of the integration-specific
    hacks inside this driver.  Regulator control has not yet been
    converted; the driver still uses the platform_data set_power hook.

    In converting to runtime PM layer, the clock frameworks is no longer
    used for fclk and iclk.  Instead, the runtime PM get and put functions
    are used.  These result in calls into the OMAP runtime PM core which
    internally uses the omap_device API to disable/re-enable the device.
    (Note that the 2430 debounce clock is not currently handled here,
    only the fclk and iclk are managed.)

    Based on an initial conversion of this driver to use omap_device by
    by Paul Walmsely: http://marc.info/?l=linux-omap&m=124419789124570&w=2
    and then converted to use runtime PM API instead of omap_device API.

    The omap_hsmmc driver has some hacks in this version to compensate for
    the fact that the main runtime PM core prevents runtime transitions
    during suspend.  This prevens us from using common hooks for runtime
    PM and static PM.  Current workaround is to hack in some extra put/get
    calls in the suspend/resume path while this issue is being discussed
    on linux-pm.

    Cc: Paul Walmsley <paul@pwsan.com>
    Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
    Signed-off-by: Kishore Kadiyala <kishore.kadiyala@ti.com>

1 files changed, 134 insertions, 128 deletions

diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 4c6c374aff19..a4b235db751f 100755
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -160,12 +160,10 @@ struct omap_hsmmc_host {
 	 */
 	struct	regulator	*vcc;
 	struct	regulator	*vcc_aux;
-	struct	semaphore	sem;
 	struct	work_struct	mmc_carddetect_work;
 	void	__iomem		*base;
 	resource_size_t		mapbase;
 	spinlock_t		irq_lock; /* Prevent races with irq handler */
-	unsigned long		flags;
 	unsigned int		id;
 	unsigned int		dma_len;
 	unsigned int		dma_sg_idx;
@@ -186,6 +184,7 @@ struct omap_hsmmc_host {
 	int			protect_card;
 	int			reqs_blocked;
 	int			use_reg;
+	int			req_in_progress;
 
 	struct	omap_mmc_platform_data	*pdata;
 };
@@ -544,6 +543,27 @@ static void omap_hsmmc_stop_clock(struct omap_hsmmc_host *host)
 		dev_dbg(mmc_dev(host->mmc), "MMC Clock is not stoped\n");
 }
 
+static void omap_hsmmc_enable_irq(struct omap_hsmmc_host *host)
+{
+	unsigned int irq_mask;
+
+	if (host->use_dma)
+		irq_mask = INT_EN_MASK & ~(BRR_ENABLE | BWR_ENABLE);
+	else
+		irq_mask = INT_EN_MASK;
+
+	OMAP_HSMMC_WRITE(host->base, STAT, STAT_CLEAR);
+	OMAP_HSMMC_WRITE(host->base, ISE, irq_mask);
+	OMAP_HSMMC_WRITE(host->base, IE, irq_mask);
+}
+
+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);
+	OMAP_HSMMC_WRITE(host->base, STAT, STAT_CLEAR);
+}
+
 #ifdef CONFIG_PM
 
 /*
@@ -612,9 +632,7 @@ static int omap_hsmmc_context_restore(struct omap_hsmmc_host *host)
 		&& time_before(jiffies, timeout))
 		;
 
-	OMAP_HSMMC_WRITE(host->base, STAT, STAT_CLEAR);
-	OMAP_HSMMC_WRITE(host->base, ISE, INT_EN_MASK);
-	OMAP_HSMMC_WRITE(host->base, IE, INT_EN_MASK);
+	omap_hsmmc_disable_irq(host);
 
 	/* Do not initialize card-specific things if the power is off */
 	if (host->power_mode == MMC_POWER_OFF)
@@ -717,6 +735,8 @@ static void send_init_stream(struct omap_hsmmc_host *host)
 		return;
 
 	disable_irq(host->irq);
+
+	OMAP_HSMMC_WRITE(host->base, IE, INT_EN_MASK);
 	OMAP_HSMMC_WRITE(host->base, CON,
 		OMAP_HSMMC_READ(host->base, CON) | INIT_STREAM);
 	OMAP_HSMMC_WRITE(host->base, CMD, INIT_STREAM_CMD);
@@ -782,17 +802,7 @@ omap_hsmmc_start_command(struct omap_hsmmc_host *host, struct mmc_command *cmd,
 		mmc_hostname(host->mmc), cmd->opcode, cmd->arg);
 	host->cmd = cmd;
 
-	/*
-	 * Clear status bits and enable interrupts
-	 */
-	OMAP_HSMMC_WRITE(host->base, STAT, STAT_CLEAR);
-	OMAP_HSMMC_WRITE(host->base, ISE, INT_EN_MASK);
-
-	if (host->use_dma)
-		OMAP_HSMMC_WRITE(host->base, IE,
-				 INT_EN_MASK & ~(BRR_ENABLE | BWR_ENABLE));
-	else
-		OMAP_HSMMC_WRITE(host->base, IE, INT_EN_MASK);
+	omap_hsmmc_enable_irq(host);
 
 	host->response_busy = 0;
 	if (cmd->flags & MMC_RSP_PRESENT) {
@@ -826,13 +836,7 @@ omap_hsmmc_start_command(struct omap_hsmmc_host *host, struct mmc_command *cmd,
 	if (host->use_dma)
 		cmdreg |= DMA_EN;
 
-	/*
-	 * In an interrupt context (i.e. STOP command), the spinlock is unlocked
-	 * by the interrupt handler, otherwise (i.e. for a new request) it is
-	 * unlocked here.
-	 */
-	if (!in_interrupt())
-		spin_unlock_irqrestore(&host->irq_lock, host->flags);
+	host->req_in_progress = 1;
 
 	OMAP_HSMMC_WRITE(host->base, ARG, cmd->arg);
 	OMAP_HSMMC_WRITE(host->base, CMD, cmdreg);
@@ -847,6 +851,23 @@ omap_hsmmc_get_dma_dir(struct omap_hsmmc_host *host, struct mmc_data *data)
 		return DMA_FROM_DEVICE;
 }
 
+static void omap_hsmmc_request_done(struct omap_hsmmc_host *host, struct mmc_request *mrq)
+{
+	int dma_ch;
+
+	spin_lock(&host->irq_lock);
+	host->req_in_progress = 0;
+	dma_ch = host->dma_ch;
+	spin_unlock(&host->irq_lock);
+
+	omap_hsmmc_disable_irq(host);
+	/* Do not complete the request if DMA is still in progress */
+	if (mrq->data && host->use_dma && dma_ch != -1)
+		return;
+	host->mrq = NULL;
+	mmc_request_done(host->mmc, mrq);
+}
+
 /*
  * Notify the transfer complete to MMC core
  */
@@ -863,25 +884,19 @@ omap_hsmmc_xfer_done(struct omap_hsmmc_host *host, struct mmc_data *data)
 			return;
 		}
 
-		host->mrq = NULL;
-		mmc_request_done(host->mmc, mrq);
+		omap_hsmmc_request_done(host, mrq);
 		return;
 	}
 
 	host->data = NULL;
 
-	if (host->use_dma && host->dma_ch != -1)
-		dma_unmap_sg(mmc_dev(host->mmc), data->sg, host->dma_len,
-			omap_hsmmc_get_dma_dir(host, data));
-
 	if (!data->error)
 		data->bytes_xfered += data->blocks * (data->blksz);
 	else
 		data->bytes_xfered = 0;
 
 	if (!data->stop) {
-		host->mrq = NULL;
-		mmc_request_done(host->mmc, data->mrq);
+		omap_hsmmc_request_done(host, data->mrq);
 		return;
 	}
 	omap_hsmmc_start_command(host, data->stop, NULL);
@@ -907,10 +922,8 @@ omap_hsmmc_cmd_done(struct omap_hsmmc_host *host, struct mmc_command *cmd)
 			cmd->resp[0] = OMAP_HSMMC_READ(host->base, RSP10);
 		}
 	}
-	if ((host->data == NULL && !host->response_busy) || cmd->error) {
-		host->mrq = NULL;
-		mmc_request_done(host->mmc, cmd->mrq);
-	}
+	if ((host->data == NULL && !host->response_busy) || cmd->error)
+		omap_hsmmc_request_done(host, cmd->mrq);
 }
 
 /*
@@ -918,14 +931,19 @@ omap_hsmmc_cmd_done(struct omap_hsmmc_host *host, struct mmc_command *cmd)
  */
 static void omap_hsmmc_dma_cleanup(struct omap_hsmmc_host *host, int errno)
 {
+	int dma_ch;
+
 	host->data->error = errno;
 
-	if (host->use_dma && host->dma_ch != -1) {
+	spin_lock(&host->irq_lock);
+	dma_ch = host->dma_ch;
+	host->dma_ch = -1;
+	spin_unlock(&host->irq_lock);
+
+	if (host->use_dma && dma_ch != -1) {
 		dma_unmap_sg(mmc_dev(host->mmc), host->data->sg, host->dma_len,
 			omap_hsmmc_get_dma_dir(host, host->data));
-		omap_free_dma(host->dma_ch);
-		host->dma_ch = -1;
-		up(&host->sem);
+		omap_free_dma(dma_ch);
 	}
 	host->data = NULL;
 }
@@ -995,28 +1013,21 @@ static inline void omap_hsmmc_reset_controller_fsm(struct omap_hsmmc_host *host,
 			__func__);
 }
 
-/*
- * MMC controller IRQ handler
- */
-static irqreturn_t omap_hsmmc_irq(int irq, void *dev_id)
+static void omap_hsmmc_do_irq(struct omap_hsmmc_host *host, int status)
 {
-	struct omap_hsmmc_host *host = dev_id;
 	struct mmc_data *data;
-	int end_cmd = 0, end_trans = 0, status;
-
-	spin_lock(&host->irq_lock);
-
-	if (host->mrq == NULL) {
-		OMAP_HSMMC_WRITE(host->base, STAT,
-			OMAP_HSMMC_READ(host->base, STAT));
-		/* Flush posted write */
-		OMAP_HSMMC_READ(host->base, STAT);
-		spin_unlock(&host->irq_lock);
-		return IRQ_HANDLED;
+	int end_cmd = 0, end_trans = 0;
+
+	if (!host->req_in_progress) {
+		do {
+			OMAP_HSMMC_WRITE(host->base, STAT, status);
+			/* Flush posted write */
+			status = OMAP_HSMMC_READ(host->base, STAT);
+		} while (status & INT_EN_MASK);
+		return;
 	}
 
 	data = host->data;
-	status = OMAP_HSMMC_READ(host->base, STAT);
 	dev_dbg(mmc_dev(host->mmc), "IRQ Status is %x\n", status);
 
 	if (status & ERR) {
@@ -1069,15 +1080,27 @@ static irqreturn_t omap_hsmmc_irq(int irq, void *dev_id)
 	}
 
 	OMAP_HSMMC_WRITE(host->base, STAT, status);
-	/* Flush posted write */
-	OMAP_HSMMC_READ(host->base, STAT);
 
 	if (end_cmd || ((status & CC) && host->cmd))
 		omap_hsmmc_cmd_done(host, host->cmd);
 	if ((end_trans || (status & TC)) && host->mrq)
 		omap_hsmmc_xfer_done(host, data);
+}
 
-	spin_unlock(&host->irq_lock);
+/*
+ * MMC controller IRQ handler
+ */
+static irqreturn_t omap_hsmmc_irq(int irq, void *dev_id)
+{
+	struct omap_hsmmc_host *host = dev_id;
+	int status;
+
+	status = OMAP_HSMMC_READ(host->base, STAT);
+	do {
+		omap_hsmmc_do_irq(host, status);
+		/* Flush posted write */
+		status = OMAP_HSMMC_READ(host->base, STAT);
+	} while (status & INT_EN_MASK);
 
 	return IRQ_HANDLED;
 }
@@ -1272,31 +1295,47 @@ static void omap_hsmmc_config_dma_params(struct omap_hsmmc_host *host,
 /*
  * DMA call back function
  */
-static void omap_hsmmc_dma_cb(int lch, u16 ch_status, void *data)
+static void omap_hsmmc_dma_cb(int lch, u16 ch_status, void *cb_data)
 {
-	struct omap_hsmmc_host *host = data;
+	struct omap_hsmmc_host *host = cb_data;
+	struct mmc_data *data = host->mrq->data;
+	int dma_ch, req_in_progress;
 
 	if (ch_status & OMAP2_DMA_MISALIGNED_ERR_IRQ)
 		dev_dbg(mmc_dev(host->mmc), "MISALIGNED_ADRS_ERR\n");
 
-	if (host->dma_ch < 0)
+	spin_lock(&host->irq_lock);
+	if (host->dma_ch < 0) {
+		spin_unlock(&host->irq_lock);
 		return;
+	}
 
 	host->dma_sg_idx++;
 	if (host->dma_sg_idx < host->dma_len) {
 		/* Fire up the next transfer. */
-		omap_hsmmc_config_dma_params(host, host->data,
-					   host->data->sg + host->dma_sg_idx);
+		omap_hsmmc_config_dma_params(host, data,
+					   data->sg + host->dma_sg_idx);
+		spin_unlock(&host->irq_lock);
 		return;
 	}
 
-	omap_free_dma(host->dma_ch);
+	dma_unmap_sg(mmc_dev(host->mmc), data->sg, host->dma_len,
+		omap_hsmmc_get_dma_dir(host, data));
+
+	req_in_progress = host->req_in_progress;
+	dma_ch = host->dma_ch;
 	host->dma_ch = -1;
-	/*
-	 * DMA Callback: run in interrupt context.
-	 * mutex_unlock will throw a kernel warning if used.
-	 */
-	up(&host->sem);
+	spin_unlock(&host->irq_lock);
+
+	omap_free_dma(dma_ch);
+
+	/* If DMA has finished after TC, complete the request */
+	if (!req_in_progress) {
+		struct mmc_request *mrq = host->mrq;
+
+		host->mrq = NULL;
+		mmc_request_done(host->mmc, mrq);
+	}
 }
 
 /*
@@ -1305,7 +1344,7 @@ static void omap_hsmmc_dma_cb(int lch, u16 ch_status, void *data)
 static int omap_hsmmc_start_dma_transfer(struct omap_hsmmc_host *host,
 					struct mmc_request *req)
 {
-	int dma_ch = 0, ret = 0, err = 1, i;
+	int dma_ch = 0, ret = 0, i;
 	struct mmc_data *data = req->data;
 
 	/* Sanity check: all the SG entries must be aligned by block size. */
@@ -1322,23 +1361,7 @@ static int omap_hsmmc_start_dma_transfer(struct omap_hsmmc_host *host,
 		 */
 		return -EINVAL;
 
-	/*
-	 * If for some reason the DMA transfer is still active,
-	 * we wait for timeout period and free the dma
-	 */
-	if (host->dma_ch != -1) {
-		set_current_state(TASK_UNINTERRUPTIBLE);
-		schedule_timeout(100);
-		if (down_trylock(&host->sem)) {
-			omap_free_dma(host->dma_ch);
-			host->dma_ch = -1;
-			up(&host->sem);
-			return err;
-		}
-	} else {
-		if (down_trylock(&host->sem))
-			return err;
-	}
+	BUG_ON(host->dma_ch != -1);
 
 	ret = omap_request_dma(omap_hsmmc_get_dma_sync_dev(host, data),
 			       "MMC/SD", omap_hsmmc_dma_cb, host, &dma_ch);
@@ -1438,37 +1461,27 @@ static void omap_hsmmc_request(struct mmc_host *mmc, struct mmc_request *req)
 	struct omap_hsmmc_host *host = mmc_priv(mmc);
 	int err;
 
-	/*
-	 * Prevent races with the interrupt handler because of unexpected
-	 * interrupts, but not if we are already in interrupt context i.e.
-	 * retries.
-	 */
-	if (!in_interrupt()) {
-		spin_lock_irqsave(&host->irq_lock, host->flags);
-		/*
-		 * Protect the card from I/O if there is a possibility
-		 * it can be removed.
-		 */
-		if (host->protect_card) {
-			if (host->reqs_blocked < 3) {
-				/*
-				 * Ensure the controller is left in a consistent
-				 * state by resetting the command and data state
-				 * machines.
-				 */
-				omap_hsmmc_reset_controller_fsm(host, SRD);
-				omap_hsmmc_reset_controller_fsm(host, SRC);
-				host->reqs_blocked += 1;
-			}
-			req->cmd->error = -EBADF;
-			if (req->data)
-				req->data->error = -EBADF;
-			spin_unlock_irqrestore(&host->irq_lock, host->flags);
-			mmc_request_done(mmc, req);
-			return;
-		} else if (host->reqs_blocked)
-			host->reqs_blocked = 0;
-	}
+	BUG_ON(host->req_in_progress);
+	BUG_ON(host->dma_ch != -1);
+	if (host->protect_card) {
+		if (host->reqs_blocked < 3) {
+			/*
+			 * Ensure the controller is left in a consistent
+			 * state by resetting the command and data state
+			 * machines.
+			 */
+			omap_hsmmc_reset_controller_fsm(host, SRD);
+			omap_hsmmc_reset_controller_fsm(host, SRC);
+			host->reqs_blocked += 1;
+		}
+		req->cmd->error = -EBADF;
+		if (req->data)
+			req->data->error = -EBADF;
+		req->cmd->retries = 0;
+		mmc_request_done(mmc, req);
+		return;
+	} else if (host->reqs_blocked)
+		host->reqs_blocked = 0;
 	WARN_ON(host->mrq != NULL);
 	host->mrq = req;
 	err = omap_hsmmc_prepare_data(host, req);
@@ -1477,8 +1490,6 @@ static void omap_hsmmc_request(struct mmc_host *mmc, struct mmc_request *req)
 		if (req->data)
 			req->data->error = err;
 		host->mrq = NULL;
-		if (!in_interrupt())
-			spin_unlock_irqrestore(&host->irq_lock, host->flags);
 		mmc_request_done(mmc, req);
 		return;
 	}
@@ -2036,7 +2047,6 @@ static int __init omap_hsmmc_probe(struct platform_device *pdev)
 	mmc->f_min	= 400000;
 	mmc->f_max	= 52000000;
 
-	sema_init(&host->sem, 1);
 	spin_lock_init(&host->irq_lock);
 
 	host->iclk = clk_get(&pdev->dev, "ick");
@@ -2157,8 +2167,7 @@ static int __init omap_hsmmc_probe(struct platform_device *pdev)
 		}
 	}
 
-	OMAP_HSMMC_WRITE(host->base, ISE, INT_EN_MASK);
-	OMAP_HSMMC_WRITE(host->base, IE, INT_EN_MASK);
+	omap_hsmmc_disable_irq(host);
 
 	mmc_host_lazy_disable(host->mmc);
 
@@ -2281,10 +2290,7 @@ static int omap_hsmmc_suspend(struct device *dev)
 		mmc_host_enable(host->mmc);
 		ret = mmc_suspend_host(host->mmc, state);
 		if (ret == 0) {
-			OMAP_HSMMC_WRITE(host->base, ISE, 0);
-			OMAP_HSMMC_WRITE(host->base, IE, 0);
-
-
+			omap_hsmmc_disable_irq(host);
 			OMAP_HSMMC_WRITE(host->base, HCTL,
 				OMAP_HSMMC_READ(host->base, HCTL) & ~SDBP);
 			mmc_host_disable(host->mmc);