Merge branch 'topic/qcom' into for-linus

Documentation/devicetree/bindings/dma/qcom_hidma_mgmt.txt

@@ -5,13 +5,13 @@ memcpy and memset capabilities. It has been designed for virtualized
 environments.
 
 Each HIDMA HW instance consists of multiple DMA channels. These channels
-share the same bandwidth. The bandwidth utilization can be parititioned
+share the same bandwidth. The bandwidth utilization can be partitioned
 among channels based on the priority and weight assignments.
 
 There are only two priority levels and 15 weigh assignments possible.
 
 Other parameters here determine how much of the system bus this HIDMA
-instance can use like maximum read/write request and and number of bytes to
+instance can use like maximum read/write request and number of bytes to
 read/write in a single burst.
 
 Main node required properties:
@@ -47,12 +47,18 @@ When the OS is not in control of the management interface (i.e. it's a guest),
 the channel nodes appear on their own, not under a management node.
 
 Required properties:
-- compatible: must contain "qcom,hidma-1.0"
+- compatible: must contain "qcom,hidma-1.0" for initial HW or "qcom,hidma-1.1"
+for MSI capable HW.
 - reg: Addresses for the transfer and event channel
 - interrupts: Should contain the event interrupt
 - desc-count: Number of asynchronous requests this channel can handle
 - iommus: required a iommu node
 
+Optional properties for MSI:
+- msi-parent : See the generic MSI binding described in
+ devicetree/bindings/interrupt-controller/msi.txt for a description of the
+ msi-parent property.
+
 Example:
 
 Hypervisor OS configuration:

drivers/dma/qcom/hidma.c

@@ -56,6 +56,7 @@
 #include <linux/irq.h>
 #include <linux/atomic.h>
 #include <linux/pm_runtime.h>
+#include <linux/msi.h>
 
 #include "../dmaengine.h"
 #include "hidma.h"
@@ -70,6 +71,7 @@
 #define HIDMA_ERR_INFO_SW			0xFF
 #define HIDMA_ERR_CODE_UNEXPECTED_TERMINATE	0x0
 #define HIDMA_NR_DEFAULT_DESC			10
+#define HIDMA_MSI_INTS				11
 
 static inline struct hidma_dev *to_hidma_dev(struct dma_device *dmadev)
 {
@@ -553,6 +555,17 @@ static irqreturn_t hidma_chirq_handler(int chirq, void *arg)
 	return hidma_ll_inthandler(chirq, lldev);
 }
 
+#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
+static irqreturn_t hidma_chirq_handler_msi(int chirq, void *arg)
+{
+	struct hidma_lldev **lldevp = arg;
+	struct hidma_dev *dmadev = to_hidma_dev_from_lldev(lldevp);
+
+	return hidma_ll_inthandler_msi(chirq, *lldevp,
+				       1 << (chirq - dmadev->msi_virqbase));
+}
+#endif
+
 static ssize_t hidma_show_values(struct device *dev,
 				 struct device_attribute *attr, char *buf)
 {
@@ -567,8 +580,13 @@ static ssize_t hidma_show_values(struct device *dev,
 	return strlen(buf);
 }
 
-static int hidma_create_sysfs_entry(struct hidma_dev *dev, char *name,
+static inline void  hidma_sysfs_uninit(struct hidma_dev *dev)
-				    int mode)
+{
+	device_remove_file(dev->ddev.dev, dev->chid_attrs);
+}
+
+static struct device_attribute*
+hidma_create_sysfs_entry(struct hidma_dev *dev, char *name, int mode)
 {
 	struct device_attribute *attrs;
 	char *name_copy;
@@ -576,18 +594,125 @@ static int hidma_create_sysfs_entry(struct hidma_dev *dev, char *name,
 	attrs = devm_kmalloc(dev->ddev.dev, sizeof(struct device_attribute),
 			     GFP_KERNEL);
 	if (!attrs)
-		return -ENOMEM;
+		return NULL;
 
 	name_copy = devm_kstrdup(dev->ddev.dev, name, GFP_KERNEL);
 	if (!name_copy)
-		return -ENOMEM;
+		return NULL;
 
 	attrs->attr.name = name_copy;
 	attrs->attr.mode = mode;
 	attrs->show = hidma_show_values;
 	sysfs_attr_init(&attrs->attr);
 
-	return device_create_file(dev->ddev.dev, attrs);
+	return attrs;
+}
+
+static int hidma_sysfs_init(struct hidma_dev *dev)
+{
+	dev->chid_attrs = hidma_create_sysfs_entry(dev, "chid", S_IRUGO);
+	if (!dev->chid_attrs)
+		return -ENOMEM;
+
+	return device_create_file(dev->ddev.dev, dev->chid_attrs);
+}
+
+#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
+static void hidma_write_msi_msg(struct msi_desc *desc, struct msi_msg *msg)
+{
+	struct device *dev = msi_desc_to_dev(desc);
+	struct hidma_dev *dmadev = dev_get_drvdata(dev);
+
+	if (!desc->platform.msi_index) {
+		writel(msg->address_lo, dmadev->dev_evca + 0x118);
+		writel(msg->address_hi, dmadev->dev_evca + 0x11C);
+		writel(msg->data, dmadev->dev_evca + 0x120);
+	}
+}
+#endif
+
+static void hidma_free_msis(struct hidma_dev *dmadev)
+{
+#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
+	struct device *dev = dmadev->ddev.dev;
+	struct msi_desc *desc;
+
+	/* free allocated MSI interrupts above */
+	for_each_msi_entry(desc, dev)
+		devm_free_irq(dev, desc->irq, &dmadev->lldev);
+
+	platform_msi_domain_free_irqs(dev);
+#endif
+}
+
+static int hidma_request_msi(struct hidma_dev *dmadev,
+			     struct platform_device *pdev)
+{
+#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
+	int rc;
+	struct msi_desc *desc;
+	struct msi_desc *failed_desc = NULL;
+
+	rc = platform_msi_domain_alloc_irqs(&pdev->dev, HIDMA_MSI_INTS,
+					    hidma_write_msi_msg);
+	if (rc)
+		return rc;
+
+	for_each_msi_entry(desc, &pdev->dev) {
+		if (!desc->platform.msi_index)
+			dmadev->msi_virqbase = desc->irq;
+
+		rc = devm_request_irq(&pdev->dev, desc->irq,
+				       hidma_chirq_handler_msi,
+				       0, "qcom-hidma-msi",
+				       &dmadev->lldev);
+		if (rc) {
+			failed_desc = desc;
+			break;
+		}
+	}
+
+	if (rc) {
+		/* free allocated MSI interrupts above */
+		for_each_msi_entry(desc, &pdev->dev) {
+			if (desc == failed_desc)
+				break;
+			devm_free_irq(&pdev->dev, desc->irq,
+				      &dmadev->lldev);
+		}
+	} else {
+		/* Add callback to free MSIs on teardown */
+		hidma_ll_setup_irq(dmadev->lldev, true);
+
+	}
+	if (rc)
+		dev_warn(&pdev->dev,
+			 "failed to request MSI irq, falling back to wired IRQ\n");
+	return rc;
+#else
+	return -EINVAL;
+#endif
+}
+
+static bool hidma_msi_capable(struct device *dev)
+{
+	struct acpi_device *adev = ACPI_COMPANION(dev);
+	const char *of_compat;
+	int ret = -EINVAL;
+
+	if (!adev || acpi_disabled) {
+		ret = device_property_read_string(dev, "compatible",
+						  &of_compat);
+		if (ret)
+			return false;
+
+		ret = strcmp(of_compat, "qcom,hidma-1.1");
+	} else {
+#ifdef CONFIG_ACPI
+		ret = strcmp(acpi_device_hid(adev), "QCOM8062");
+#endif
+	}
+	return ret == 0;
 }
 
 static int hidma_probe(struct platform_device *pdev)
@@ -599,6 +724,7 @@ static int hidma_probe(struct platform_device *pdev)
 	void __iomem *evca;
 	void __iomem *trca;
 	int rc;
+	bool msi;
 
 	pm_runtime_set_autosuspend_delay(&pdev->dev, HIDMA_AUTOSUSPEND_TIMEOUT);
 	pm_runtime_use_autosuspend(&pdev->dev);
@@ -660,6 +786,12 @@ static int hidma_probe(struct platform_device *pdev)
 	dmadev->ddev.device_terminate_all = hidma_terminate_all;
 	dmadev->ddev.copy_align = 8;
 
+	/*
+	 * Determine the MSI capability of the platform. Old HW doesn't
+	 * support MSI.
+	 */
+	msi = hidma_msi_capable(&pdev->dev);
+
 	device_property_read_u32(&pdev->dev, "desc-count",
 				 &dmadev->nr_descriptors);
 
@@ -688,10 +820,17 @@ static int hidma_probe(struct platform_device *pdev)
 		goto dmafree;
 	}
 
-	rc = devm_request_irq(&pdev->dev, chirq, hidma_chirq_handler, 0,
+	platform_set_drvdata(pdev, dmadev);
-			      "qcom-hidma", dmadev->lldev);
+	if (msi)
+		rc = hidma_request_msi(dmadev, pdev);
+
+	if (!msi || rc) {
+		hidma_ll_setup_irq(dmadev->lldev, false);
+		rc = devm_request_irq(&pdev->dev, chirq, hidma_chirq_handler,
+				      0, "qcom-hidma", dmadev->lldev);
 		if (rc)
 			goto uninit;
+	}
 
 	INIT_LIST_HEAD(&dmadev->ddev.channels);
 	rc = hidma_chan_init(dmadev, 0);
@@ -705,14 +844,16 @@ static int hidma_probe(struct platform_device *pdev)
 	dmadev->irq = chirq;
 	tasklet_init(&dmadev->task, hidma_issue_task, (unsigned long)dmadev);
 	hidma_debug_init(dmadev);
-	hidma_create_sysfs_entry(dmadev, "chid", S_IRUGO);
+	hidma_sysfs_init(dmadev);
 	dev_info(&pdev->dev, "HI-DMA engine driver registration complete\n");
-	platform_set_drvdata(pdev, dmadev);
 	pm_runtime_mark_last_busy(dmadev->ddev.dev);
 	pm_runtime_put_autosuspend(dmadev->ddev.dev);
 	return 0;
 
 uninit:
+	if (msi)
+		hidma_free_msis(dmadev);
+
 	hidma_debug_uninit(dmadev);
 	hidma_ll_uninit(dmadev->lldev);
 dmafree:
@@ -730,8 +871,13 @@ static int hidma_remove(struct platform_device *pdev)
 
 	pm_runtime_get_sync(dmadev->ddev.dev);
 	dma_async_device_unregister(&dmadev->ddev);
+	if (!dmadev->lldev->msi_support)
 		devm_free_irq(dmadev->ddev.dev, dmadev->irq, dmadev->lldev);
+	else
+		hidma_free_msis(dmadev);
+
 	tasklet_kill(&dmadev->task);
+	hidma_sysfs_uninit(dmadev);
 	hidma_debug_uninit(dmadev);
 	hidma_ll_uninit(dmadev->lldev);
 	hidma_free(dmadev);
@@ -746,12 +892,15 @@ static int hidma_remove(struct platform_device *pdev)
 #if IS_ENABLED(CONFIG_ACPI)
 static const struct acpi_device_id hidma_acpi_ids[] = {
 	{"QCOM8061"},
+	{"QCOM8062"},
 	{},
 };
+MODULE_DEVICE_TABLE(acpi, hidma_acpi_ids);
 #endif
 
 static const struct of_device_id hidma_match[] = {
 	{.compatible = "qcom,hidma-1.0",},
+	{.compatible = "qcom,hidma-1.1",},
 	{},
 };
 MODULE_DEVICE_TABLE(of, hidma_match);

drivers/dma/qcom/hidma.h

@@ -46,6 +46,7 @@ struct hidma_tre {
 };
 
 struct hidma_lldev {
+	bool msi_support;		/* flag indicating MSI support    */
 	bool initialized;		/* initialized flag               */
 	u8 trch_state;			/* trch_state of the device	  */
 	u8 evch_state;			/* evch_state of the device	  */
@@ -58,7 +59,7 @@ struct hidma_lldev {
 	void __iomem *evca;		/* Event Channel address          */
 	struct hidma_tre
 		**pending_tre_list;	/* Pointers to pending TREs	  */
-	s32 pending_tre_count;		/* Number of TREs pending	  */
+	atomic_t pending_tre_count;	/* Number of TREs pending	  */
 
 	void *tre_ring;			/* TRE ring			  */
 	dma_addr_t tre_dma;		/* TRE ring to be shared with HW  */
@@ -114,6 +115,7 @@ struct hidma_dev {
 	int				irq;
 	int				chidx;
 	u32				nr_descriptors;
+	int				msi_virqbase;
 
 	struct hidma_lldev		*lldev;
 	void				__iomem *dev_trca;
@@ -128,6 +130,9 @@ struct hidma_dev {
 	struct dentry			*debugfs;
 	struct dentry			*stats;
 
+	/* sysfs entry for the channel id */
+	struct device_attribute		*chid_attrs;
+
 	/* Task delivering issue_pending */
 	struct tasklet_struct		task;
 };
@@ -145,12 +150,14 @@ int hidma_ll_disable(struct hidma_lldev *lldev);
 int hidma_ll_enable(struct hidma_lldev *llhndl);
 void hidma_ll_set_transfer_params(struct hidma_lldev *llhndl, u32 tre_ch,
 	dma_addr_t src, dma_addr_t dest, u32 len, u32 flags);
+void hidma_ll_setup_irq(struct hidma_lldev *lldev, bool msi);
 int hidma_ll_setup(struct hidma_lldev *lldev);
 struct hidma_lldev *hidma_ll_init(struct device *dev, u32 max_channels,
 			void __iomem *trca, void __iomem *evca,
 			u8 chidx);
 int hidma_ll_uninit(struct hidma_lldev *llhndl);
 irqreturn_t hidma_ll_inthandler(int irq, void *arg);
+irqreturn_t hidma_ll_inthandler_msi(int irq, void *arg, int cause);
 void hidma_cleanup_pending_tre(struct hidma_lldev *llhndl, u8 err_info,
 				u8 err_code);
 int hidma_debug_init(struct hidma_dev *dmadev);

drivers/dma/qcom/hidma_dbg.c

@@ -74,7 +74,8 @@ static void hidma_ll_devstats(struct seq_file *s, void *llhndl)
 	seq_printf(s, "tre_ring_handle=%pap\n", &lldev->tre_dma);
 	seq_printf(s, "tre_ring_size = 0x%x\n", lldev->tre_ring_size);
 	seq_printf(s, "tre_processed_off = 0x%x\n", lldev->tre_processed_off);
-	seq_printf(s, "pending_tre_count=%d\n", lldev->pending_tre_count);
+	seq_printf(s, "pending_tre_count=%d\n",
+			atomic_read(&lldev->pending_tre_count));
 	seq_printf(s, "evca=%p\n", lldev->evca);
 	seq_printf(s, "evre_ring=%p\n", lldev->evre_ring);
 	seq_printf(s, "evre_ring_handle=%pap\n", &lldev->evre_dma);
@@ -164,7 +165,6 @@ static const struct file_operations hidma_dma_fops = {
 void hidma_debug_uninit(struct hidma_dev *dmadev)
 {
 	debugfs_remove_recursive(dmadev->debugfs);
-	debugfs_remove_recursive(dmadev->stats);
 }
 
 int hidma_debug_init(struct hidma_dev *dmadev)

drivers/dma/qcom/hidma_ll.c

@@ -198,13 +198,16 @@ static void hidma_ll_tre_complete(unsigned long arg)
 	}
 }
 
-static int hidma_post_completed(struct hidma_lldev *lldev, int tre_iterator,
+static int hidma_post_completed(struct hidma_lldev *lldev, u8 err_info,
-				u8 err_info, u8 err_code)
+				u8 err_code)
 {
 	struct hidma_tre *tre;
 	unsigned long flags;
+	u32 tre_iterator;
 
 	spin_lock_irqsave(&lldev->lock, flags);
+
+	tre_iterator = lldev->tre_processed_off;
 	tre = lldev->pending_tre_list[tre_iterator / HIDMA_TRE_SIZE];
 	if (!tre) {
 		spin_unlock_irqrestore(&lldev->lock, flags);
@@ -218,12 +221,14 @@ static int hidma_post_completed(struct hidma_lldev *lldev, int tre_iterator,
 	 * Keep track of pending TREs that SW is expecting to receive
 	 * from HW. We got one now. Decrement our counter.
 	 */
-	lldev->pending_tre_count--;
+	if (atomic_dec_return(&lldev->pending_tre_count) < 0) {
-	if (lldev->pending_tre_count < 0) {
 		dev_warn(lldev->dev, "tre count mismatch on completion");
-		lldev->pending_tre_count = 0;
+		atomic_set(&lldev->pending_tre_count, 0);
 	}
 
+	HIDMA_INCREMENT_ITERATOR(tre_iterator, HIDMA_TRE_SIZE,
+				 lldev->tre_ring_size);
+	lldev->tre_processed_off = tre_iterator;
 	spin_unlock_irqrestore(&lldev->lock, flags);
 
 	tre->err_info = err_info;
@@ -245,13 +250,11 @@ static int hidma_post_completed(struct hidma_lldev *lldev, int tre_iterator,
 static int hidma_handle_tre_completion(struct hidma_lldev *lldev)
 {
 	u32 evre_ring_size = lldev->evre_ring_size;
-	u32 tre_ring_size = lldev->tre_ring_size;
 	u32 err_info, err_code, evre_write_off;
-	u32 tre_iterator, evre_iterator;
+	u32 evre_iterator;
 	u32 num_completed = 0;
 
 	evre_write_off = readl_relaxed(lldev->evca + HIDMA_EVCA_WRITE_PTR_REG);
-	tre_iterator = lldev->tre_processed_off;
 	evre_iterator = lldev->evre_processed_off;
 
 	if ((evre_write_off > evre_ring_size) ||
@@ -274,12 +277,9 @@ static int hidma_handle_tre_completion(struct hidma_lldev *lldev)
 		err_code =
 		    (cfg >> HIDMA_EVRE_CODE_BIT_POS) & HIDMA_EVRE_CODE_MASK;
 
-		if (hidma_post_completed(lldev, tre_iterator, err_info,
+		if (hidma_post_completed(lldev, err_info, err_code))
-					 err_code))
 			break;
 
-		HIDMA_INCREMENT_ITERATOR(tre_iterator, HIDMA_TRE_SIZE,
-					 tre_ring_size);
 		HIDMA_INCREMENT_ITERATOR(evre_iterator, HIDMA_EVRE_SIZE,
 					 evre_ring_size);
 
@@ -291,21 +291,22 @@ static int hidma_handle_tre_completion(struct hidma_lldev *lldev)
 		evre_write_off =
 		    readl_relaxed(lldev->evca + HIDMA_EVCA_WRITE_PTR_REG);
 		num_completed++;
+
+		/*
+		 * An error interrupt might have arrived while we are processing
+		 * the completed interrupt.
+		 */
+		if (!hidma_ll_isenabled(lldev))
+			break;
 	}
 
 	if (num_completed) {
 		u32 evre_read_off = (lldev->evre_processed_off +
 				     HIDMA_EVRE_SIZE * num_completed);
-		u32 tre_read_off = (lldev->tre_processed_off +
-				    HIDMA_TRE_SIZE * num_completed);
-
 		evre_read_off = evre_read_off % evre_ring_size;
-		tre_read_off = tre_read_off % tre_ring_size;
-
 		writel(evre_read_off, lldev->evca + HIDMA_EVCA_DOORBELL_REG);
 
 		/* record the last processed tre offset */
-		lldev->tre_processed_off = tre_read_off;
 		lldev->evre_processed_off = evre_read_off;
 	}
 
@@ -315,27 +316,10 @@ static int hidma_handle_tre_completion(struct hidma_lldev *lldev)
 void hidma_cleanup_pending_tre(struct hidma_lldev *lldev, u8 err_info,
 			       u8 err_code)
 {
-	u32 tre_iterator;
+	while (atomic_read(&lldev->pending_tre_count)) {
-	u32 tre_ring_size = lldev->tre_ring_size;
+		if (hidma_post_completed(lldev, err_info, err_code))
-	int num_completed = 0;
-	u32 tre_read_off;
-
-	tre_iterator = lldev->tre_processed_off;
-	while (lldev->pending_tre_count) {
-		if (hidma_post_completed(lldev, tre_iterator, err_info,
-					 err_code))
 			break;
-		HIDMA_INCREMENT_ITERATOR(tre_iterator, HIDMA_TRE_SIZE,
-					 tre_ring_size);
-		num_completed++;
 	}
-	tre_read_off = (lldev->tre_processed_off +
-			HIDMA_TRE_SIZE * num_completed);
-
-	tre_read_off = tre_read_off % tre_ring_size;
-
-	/* record the last processed tre offset */
-	lldev->tre_processed_off = tre_read_off;
 }
 
 static int hidma_ll_reset(struct hidma_lldev *lldev)
@@ -412,26 +396,8 @@ static int hidma_ll_reset(struct hidma_lldev *lldev)
  * requests traditionally to the destination, this concept does not apply
  * here for this HW.
  */
-irqreturn_t hidma_ll_inthandler(int chirq, void *arg)
+static void hidma_ll_int_handler_internal(struct hidma_lldev *lldev, int cause)
 {
-	struct hidma_lldev *lldev = arg;
-	u32 status;
-	u32 enable;
-	u32 cause;
-
-	/*
-	 * Fine tuned for this HW...
-	 *
-	 * This ISR has been designed for this particular hardware. Relaxed
-	 * read and write accessors are used for performance reasons due to
-	 * interrupt delivery guarantees. Do not copy this code blindly and
-	 * expect that to work.
-	 */
-	status = readl_relaxed(lldev->evca + HIDMA_EVCA_IRQ_STAT_REG);
-	enable = readl_relaxed(lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
-	cause = status & enable;
-
-	while (cause) {
 	if (cause & HIDMA_ERR_INT_MASK) {
 		dev_err(lldev->dev, "error 0x%x, disabling...\n",
 				cause);
@@ -445,16 +411,39 @@ irqreturn_t hidma_ll_inthandler(int chirq, void *arg)
 		/* Driver completes the txn and intimates the client.*/
 		hidma_cleanup_pending_tre(lldev, 0xFF,
 					  HIDMA_EVRE_STATUS_ERROR);
-			goto out;
+
+		return;
 	}
 
 	/*
+	 * Fine tuned for this HW...
+	 *
+	 * This ISR has been designed for this particular hardware. Relaxed
+	 * read and write accessors are used for performance reasons due to
+	 * interrupt delivery guarantees. Do not copy this code blindly and
+	 * expect that to work.
+	 *
 	 * Try to consume as many EVREs as possible.
 	 */
 	hidma_handle_tre_completion(lldev);
 
 	/* We consumed TREs or there are pending TREs or EVREs. */
 	writel_relaxed(cause, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
+}
+
+irqreturn_t hidma_ll_inthandler(int chirq, void *arg)
+{
+	struct hidma_lldev *lldev = arg;
+	u32 status;
+	u32 enable;
+	u32 cause;
+
+	status = readl_relaxed(lldev->evca + HIDMA_EVCA_IRQ_STAT_REG);
+	enable = readl_relaxed(lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
+	cause = status & enable;
+
+	while (cause) {
+		hidma_ll_int_handler_internal(lldev, cause);
 
 		/*
 		 * Another interrupt might have arrived while we are
@@ -465,7 +454,14 @@ irqreturn_t hidma_ll_inthandler(int chirq, void *arg)
 		cause = status & enable;
 	}
 
-out:
+	return IRQ_HANDLED;
+}
+
+irqreturn_t hidma_ll_inthandler_msi(int chirq, void *arg, int cause)
+{
+	struct hidma_lldev *lldev = arg;
+
+	hidma_ll_int_handler_internal(lldev, cause);
 	return IRQ_HANDLED;
 }
 
@@ -548,7 +544,7 @@ void hidma_ll_queue_request(struct hidma_lldev *lldev, u32 tre_ch)
 	tre->err_code = 0;
 	tre->err_info = 0;
 	tre->queued = 1;
-	lldev->pending_tre_count++;
+	atomic_inc(&lldev->pending_tre_count);
 	lldev->tre_write_offset = (lldev->tre_write_offset + HIDMA_TRE_SIZE)
 					% lldev->tre_ring_size;
 	spin_unlock_irqrestore(&lldev->lock, flags);
@@ -564,19 +560,8 @@ int hidma_ll_disable(struct hidma_lldev *lldev)
 	u32 val;
 	int ret;
 
-	val = readl(lldev->evca + HIDMA_EVCA_CTRLSTS_REG);
+	/* The channel needs to be in working state */
-	lldev->evch_state = HIDMA_CH_STATE(val);
+	if (!hidma_ll_isenabled(lldev))
-	val = readl(lldev->trca + HIDMA_TRCA_CTRLSTS_REG);
-	lldev->trch_state = HIDMA_CH_STATE(val);
-
-	/* already suspended by this OS */
-	if ((lldev->trch_state == HIDMA_CH_SUSPENDED) ||
-	    (lldev->evch_state == HIDMA_CH_SUSPENDED))
-		return 0;
-
-	/* already stopped by the manager */
-	if ((lldev->trch_state == HIDMA_CH_STOPPED) ||
-	    (lldev->evch_state == HIDMA_CH_STOPPED))
 		return 0;
 
 	val = readl(lldev->trca + HIDMA_TRCA_CTRLSTS_REG);
@@ -654,7 +639,7 @@ int hidma_ll_setup(struct hidma_lldev *lldev)
 	u32 val;
 	u32 nr_tres = lldev->nr_tres;
 
-	lldev->pending_tre_count = 0;
+	atomic_set(&lldev->pending_tre_count, 0);
 	lldev->tre_processed_off = 0;
 	lldev->evre_processed_off = 0;
 	lldev->tre_write_offset = 0;
@@ -691,17 +676,36 @@ int hidma_ll_setup(struct hidma_lldev *lldev)
 	writel(HIDMA_EVRE_SIZE * nr_tres,
 			lldev->evca + HIDMA_EVCA_RING_LEN_REG);
 
-	/* support IRQ only for now */
+	/* configure interrupts */
+	hidma_ll_setup_irq(lldev, lldev->msi_support);
+
+	rc = hidma_ll_enable(lldev);
+	if (rc)
+		return rc;
+
+	return rc;
+}
+
+void hidma_ll_setup_irq(struct hidma_lldev *lldev, bool msi)
+{
+	u32 val;
+
+	lldev->msi_support = msi;
+
+	/* disable interrupts again after reset */
+	writel(0, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
+	writel(0, lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
+
+	/* support IRQ by default */
 	val = readl(lldev->evca + HIDMA_EVCA_INTCTRL_REG);
 	val &= ~0xF;
-	val |= 0x1;
+	if (!lldev->msi_support)
+		val = val | 0x1;
 	writel(val, lldev->evca + HIDMA_EVCA_INTCTRL_REG);
 
 	/* clear all pending interrupts and enable them */
 	writel(ENABLE_IRQS, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
 	writel(ENABLE_IRQS, lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
-
-	return hidma_ll_enable(lldev);
 }
 
 struct hidma_lldev *hidma_ll_init(struct device *dev, u32 nr_tres,
@@ -816,7 +820,7 @@ int hidma_ll_uninit(struct hidma_lldev *lldev)
 	tasklet_kill(&lldev->task);
 	memset(lldev->trepool, 0, required_bytes);
 	lldev->trepool = NULL;
-	lldev->pending_tre_count = 0;
+	atomic_set(&lldev->pending_tre_count, 0);
 	lldev->tre_write_offset = 0;
 
 	rc = hidma_ll_reset(lldev);

drivers/dma/qcom/hidma_mgmt.c

@@ -282,6 +282,7 @@ static const struct acpi_device_id hidma_mgmt_acpi_ids[] = {
 	{"QCOM8060"},
 	{},
 };
+MODULE_DEVICE_TABLE(acpi, hidma_mgmt_acpi_ids);
 #endif
 
 static const struct of_device_id hidma_mgmt_match[] = {
@@ -375,8 +376,15 @@ static int __init hidma_mgmt_of_populate_channels(struct device_node *np)
 			ret = PTR_ERR(new_pdev);
 			goto out;
 		}
+		of_node_get(child);
+		new_pdev->dev.of_node = child;
 		of_dma_configure(&new_pdev->dev, child);
-
+		/*
+		 * It is assumed that calling of_msi_configure is safe on
+		 * platforms with or without MSI support.
+		 */
+		of_msi_configure(&new_pdev->dev, child);
+		of_node_put(child);
 		kfree(res);
 		res = NULL;
 	}
@@ -395,7 +403,6 @@ static int __init hidma_mgmt_init(void)
 	for_each_matching_node(child, hidma_mgmt_match) {
 		/* device tree based firmware here */
 		hidma_mgmt_of_populate_channels(child);
-		of_node_put(child);
 	}
 #endif
 	platform_driver_register(&hidma_mgmt_driver);

drivers/of/irq.c

@@ -697,3 +697,4 @@ void of_msi_configure(struct device *dev, struct device_node *np)
 	dev_set_msi_domain(dev,
 			   of_msi_get_domain(dev, np, DOMAIN_BUS_PLATFORM_MSI));
 }
+EXPORT_SYMBOL_GPL(of_msi_configure);