[PATCH 10/10] dmaengine: qcom_hidma: add MSI support for interrupts

Sinan Kaya
2016-07-18T18:41:17Z

The interrupts can now be delivered as platform MSI interrupts
on newer platforms. The code looks for a new OF and ACPI strings
in order to enable the functionality.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
drivers/dma/qcom/hidma.c | 128 ++++++++++++++++++++++++++++++++++++++++++--
drivers/dma/qcom/hidma.h | 2 +
drivers/dma/qcom/hidma_ll.c | 8 +++
3 files changed, 133 insertions(+), 5 deletions(-)

diff --git a/drivers/dma/qcom/hidma.c b/drivers/dma/qcom/hidma.c
index 41b5c6d..6a0eef2 100644
--- a/drivers/dma/qcom/hidma.c
+++ b/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)
{
@@ -530,6 +532,15 @@ static irqreturn_t hidma_chirq_handler(int chirq, void *arg)
return hidma_ll_inthandler(chirq, lldev);
}

+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));
+}
+
static ssize_t hidma_show_values(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -567,6 +578,98 @@ static int hidma_create_sysfs_entry(struct hidma_dev *dev, char *name,
return device_create_file(dev->ddev.dev, 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);
+ }
+}
+
+static void hidma_free_msis(void *data)
+{
+ struct device *dev = data;
+
+ 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 */
+ devm_add_action(&pdev->dev, hidma_free_msis,
+ &pdev->dev);
+ 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;
+
+ 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 {
+ ret = strcmp(acpi_device_hid(adev), "QCOM8062");
+ }
+
+ return ret == 0;
+}
+
static int hidma_probe(struct platform_device *pdev)
{
struct hidma_dev *dmadev;
@@ -576,6 +679,7 @@ 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);
@@ -637,6 +741,12 @@ 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);

@@ -665,10 +775,17 @@ static int hidma_probe(struct platform_device *pdev)
goto dmafree;
}

- rc = devm_request_irq(&pdev->dev, chirq, hidma_chirq_handler, 0,
- "qcom-hidma", dmadev->lldev);
- if (rc)
- goto uninit;
+ platform_set_drvdata(pdev, dmadev);
+ 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);
@@ -684,7 +801,6 @@ static int hidma_probe(struct platform_device *pdev)
hidma_debug_init(dmadev);
hidma_create_sysfs_entry(dmadev, "chid", S_IRUGO);
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;
@@ -722,12 +838,14 @@ static int hidma_remove(struct platform_device *pdev)
#if IS_ENABLED(CONFIG_ACPI)
static const struct acpi_device_id hidma_acpi_ids[] = {
{"QCOM8061"},
+ {"QCOM8062"},
{},
};
#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);
diff --git a/drivers/dma/qcom/hidma.h b/drivers/dma/qcom/hidma.h
index 3f28f39..1c3df47 100644
--- a/drivers/dma/qcom/hidma.h
+++ b/drivers/dma/qcom/hidma.h
@@ -116,6 +116,7 @@ struct hidma_dev {
int irq;
int chidx;
u32 nr_descriptors;
+ int msi_virqbase;

struct hidma_lldev *lldev;
void __iomem *dev_trca;
@@ -154,6 +155,7 @@ struct hidma_lldev *hidma_ll_init(struct device *dev, u32 max_channels,
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);
diff --git a/drivers/dma/qcom/hidma_ll.c b/drivers/dma/qcom/hidma_ll.c
index c3d3252..0cf01bc 100644
--- a/drivers/dma/qcom/hidma_ll.c
+++ b/drivers/dma/qcom/hidma_ll.c
@@ -449,6 +449,14 @@ irqreturn_t hidma_ll_inthandler(int chirq, void *arg)
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;
+}
+
int hidma_ll_enable(struct hidma_lldev *lldev)
{
u32 val;
--
1.8.2.1