Linux/AM3352: USB device unbind issue

From c1b32ac75ef78eb0fe22bc1e7f09755744f1c670 Mon Sep 17 00:00:00 2001
From: Alexandre Bailon <abailon@baylibre.com>
Date: Fri, 17 Mar 2017 19:41:57 +0530
Subject: [PATCH] usb: musb: dsps: Manage CPPI 4.1 DMA interrupt in DSPS

commit 255348289f714b96e0e95f9b702f435a638e6fd4 upstream.

Despite the CPPI 4.1 is a generic DMA, it is tied to USB.
On the DSPS, CPPI 4.1 interrupt's registers are in USBSS (the MUSB glue).
Currently, to enable / disable and clear interrupts, the CPPI 4.1 driver
maps and accesses to USBSS's register, which making CPPI 4.1 driver not
really generic.
Move the interrupt management to DSPS driver.

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
---
 drivers/dma/cppi41.c         | 28 ++++-----------
 drivers/usb/musb/musb_dsps.c | 81 ++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 86 insertions(+), 23 deletions(-)

diff --git a/drivers/dma/cppi41.c b/drivers/dma/cppi41.c
index 200828c..d74cee0 100644
--- a/drivers/dma/cppi41.c
+++ b/drivers/dma/cppi41.c
@@ -79,14 +79,6 @@
 #define QMGR_QUEUE_C(n)	(0x2008 + (n) * 0x10)
 #define QMGR_QUEUE_D(n)	(0x200c + (n) * 0x10)
 
-/* Glue layer specific */
-/* USBSS  / USB AM335x */
-#define USBSS_IRQ_STATUS	0x28
-#define USBSS_IRQ_ENABLER	0x2c
-#define USBSS_IRQ_CLEARR	0x30
-
-#define USBSS_IRQ_PD_COMP	(1 <<  2)
-
 /* Packet Descriptor */
 #define PD2_ZERO_LENGTH		(1 << 19)
 
@@ -294,14 +286,8 @@ static irqreturn_t cppi41_irq(int irq, void *data)
 {
 	struct cppi41_dd *cdd = data;
 	struct cppi41_channel *c;
-	u32 status;
 	int i;
 
-	status = cppi_readl(cdd->usbss_mem + USBSS_IRQ_STATUS);
-	if (!(status & USBSS_IRQ_PD_COMP))
-		return IRQ_NONE;
-	cppi_writel(status, cdd->usbss_mem + USBSS_IRQ_STATUS);
-
 	for (i = QMGR_PENDING_SLOT_Q(FIST_COMPLETION_QUEUE); i < QMGR_NUM_PEND;
 			i++) {
 		u32 val;
@@ -618,6 +604,7 @@ static void cppi41_compute_td_desc(struct cppi41_desc *d)
 
 static int cppi41_tear_down_chan(struct cppi41_channel *c)
 {
+	struct dmaengine_result abort_result;
 	struct cppi41_dd *cdd = c->cdd;
 	struct cppi41_desc *td;
 	u32 reg;
@@ -701,6 +688,12 @@ static int cppi41_tear_down_chan(struct cppi41_channel *c)
 	c->td_seen = 0;
 	c->td_desc_seen = 0;
 	cppi_writel(0, c->gcr_reg);
+
+	/* Invoke the callback to do the necessary clean-up */
+	abort_result.result = DMA_TRANS_ABORTED;
+	dma_cookie_complete(&c->txd);
+	dmaengine_desc_get_callback_invoke(&c->txd, &abort_result);
+
 	return 0;
 }
 
@@ -1066,8 +1059,6 @@ static int cppi41_dma_probe(struct platform_device *pdev)
 		goto err_irq;
 	}
 
-	cppi_writel(USBSS_IRQ_PD_COMP, cdd->usbss_mem + USBSS_IRQ_ENABLER);
-
 	ret = devm_request_irq(&pdev->dev, irq, glue_info->isr, IRQF_SHARED,
 			dev_name(dev), cdd);
 	if (ret)
@@ -1091,7 +1082,6 @@ static int cppi41_dma_probe(struct platform_device *pdev)
 	dma_async_device_unregister(&cdd->ddev);
 err_dma_reg:
 err_irq:
-	cppi_writel(0, cdd->usbss_mem + USBSS_IRQ_CLEARR);
 	cleanup_chans(cdd);
 err_chans:
 	deinit_cppi41(dev, cdd);
@@ -1119,7 +1109,6 @@ static int cppi41_dma_remove(struct platform_device *pdev)
 	of_dma_controller_free(pdev->dev.of_node);
 	dma_async_device_unregister(&cdd->ddev);
 
-	cppi_writel(0, cdd->usbss_mem + USBSS_IRQ_CLEARR);
 	devm_free_irq(&pdev->dev, cdd->irq, cdd);
 	cleanup_chans(cdd);
 	deinit_cppi41(&pdev->dev, cdd);
@@ -1138,7 +1127,6 @@ static int __maybe_unused cppi41_suspend(struct device *dev)
 	struct cppi41_dd *cdd = dev_get_drvdata(dev);
 
 	cdd->dma_tdfdq = cppi_readl(cdd->ctrl_mem + DMA_TDFDQ);
-	cppi_writel(0, cdd->usbss_mem + USBSS_IRQ_CLEARR);
 	disable_sched(cdd);
 
 	return 0;
@@ -1164,8 +1152,6 @@ static int __maybe_unused cppi41_resume(struct device *dev)
 	cppi_writel(QMGR_SCRATCH_SIZE, cdd->qmgr_mem + QMGR_LRAM_SIZE);
 	cppi_writel(0, cdd->qmgr_mem + QMGR_LRAM1_BASE);
 
-	cppi_writel(USBSS_IRQ_PD_COMP, cdd->usbss_mem + USBSS_IRQ_ENABLER);
-
 	return 0;
 }
 
diff --git a/drivers/usb/musb/musb_dsps.c b/drivers/usb/musb/musb_dsps.c
index c171a0f1..7c047c4 100644
--- a/drivers/usb/musb/musb_dsps.c
+++ b/drivers/usb/musb/musb_dsps.c
@@ -122,6 +122,7 @@ struct dsps_glue {
 	struct timer_list timer;	/* otg_workaround timer */
 	unsigned long last_timer;    /* last timer data for each instance */
 	bool sw_babble_enabled;
+	void __iomem *usbss_base;
 
 	struct dsps_context context;
 	struct debugfs_regset32 regset;
@@ -169,6 +170,13 @@ static void dsps_mod_timer_optional(struct dsps_glue *glue)
 	dsps_mod_timer(glue, -1);
 }
 
+/* USBSS  / USB AM335x */
+#define USBSS_IRQ_STATUS	0x28
+#define USBSS_IRQ_ENABLER	0x2c
+#define USBSS_IRQ_CLEARR	0x30
+
+#define USBSS_IRQ_PD_COMP	(1 << 2)
+
 /**
  * dsps_musb_enable - enable interrupts
  */
@@ -641,14 +649,76 @@ static void dsps_read_fifo32(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
 	}
 }
 
+#ifdef CONFIG_USB_TI_CPPI41_DMA
+static void dsps_dma_controller_callback(struct dma_controller *c)
+{
+	struct musb *musb = c->musb;
+	struct dsps_glue *glue = dev_get_drvdata(musb->controller->parent);
+	void __iomem *usbss_base = glue->usbss_base;
+	u32 status;
+
+	status = musb_readl(usbss_base, USBSS_IRQ_STATUS);
+	if (status & USBSS_IRQ_PD_COMP)
+		musb_writel(usbss_base, USBSS_IRQ_STATUS, USBSS_IRQ_PD_COMP);
+}
+
+static struct dma_controller *
+dsps_dma_controller_create(struct musb *musb, void __iomem *base)
+{
+	struct dma_controller *controller;
+	struct dsps_glue *glue = dev_get_drvdata(musb->controller->parent);
+	void __iomem *usbss_base = glue->usbss_base;
+
+	controller = cppi41_dma_controller_create(musb, base);
+	if (IS_ERR_OR_NULL(controller))
+		return controller;
+
+	musb_writel(usbss_base, USBSS_IRQ_ENABLER, USBSS_IRQ_PD_COMP);
+	controller->dma_callback = dsps_dma_controller_callback;
+
+	return controller;
+}
+
+static void dsps_dma_controller_destroy(struct dma_controller *c)
+{
+	struct musb *musb = c->musb;
+	struct dsps_glue *glue = dev_get_drvdata(musb->controller->parent);
+	void __iomem *usbss_base = glue->usbss_base;
+
+	musb_writel(usbss_base, USBSS_IRQ_CLEARR, USBSS_IRQ_PD_COMP);
+	cppi41_dma_controller_destroy(c);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static void dsps_dma_controller_suspend(struct dsps_glue *glue)
+{
+	void __iomem *usbss_base = glue->usbss_base;
+
+	musb_writel(usbss_base, USBSS_IRQ_CLEARR, USBSS_IRQ_PD_COMP);
+}
+
+static void dsps_dma_controller_resume(struct dsps_glue *glue)
+{
+	void __iomem *usbss_base = glue->usbss_base;
+
+	musb_writel(usbss_base, USBSS_IRQ_ENABLER, USBSS_IRQ_PD_COMP);
+}
+#endif
+#else /* CONFIG_USB_TI_CPPI41_DMA */
+#ifdef CONFIG_PM_SLEEP
+static void dsps_dma_controller_suspend(struct dsps_glue *glue) {}
+static void dsps_dma_controller_resume(struct dsps_glue *glue) {}
+#endif
+#endif /* CONFIG_USB_TI_CPPI41_DMA */
+
 static struct musb_platform_ops dsps_ops = {
 	.quirks		= MUSB_DMA_CPPI41 | MUSB_INDEXED_EP,
 	.init		= dsps_musb_init,
 	.exit		= dsps_musb_exit,
 
 #ifdef CONFIG_USB_TI_CPPI41_DMA
-	.dma_init	= cppi41_dma_controller_create,
-	.dma_exit	= cppi41_dma_controller_destroy,
+	.dma_init	= dsps_dma_controller_create,
+	.dma_exit	= dsps_dma_controller_destroy,
 #endif
 	.enable		= dsps_musb_enable,
 	.disable	= dsps_musb_disable,
@@ -856,6 +926,9 @@ static int dsps_probe(struct platform_device *pdev)
 
 	glue->dev = &pdev->dev;
 	glue->wrp = wrp;
+	glue->usbss_base = of_iomap(pdev->dev.parent->of_node, 0);
+	if (!glue->usbss_base)
+		return -ENXIO;
 
 	if (usb_get_dr_mode(&pdev->dev) == USB_DR_MODE_PERIPHERAL) {
 		ret = dsps_setup_optional_vbus_irq(pdev, glue);
@@ -950,6 +1023,8 @@ static int dsps_suspend(struct device *dev)
 	glue->context.tx_mode = musb_readl(mbase, wrp->tx_mode);
 	glue->context.rx_mode = musb_readl(mbase, wrp->rx_mode);
 
+	dsps_dma_controller_suspend(glue);
+
 	return 0;
 }
 
@@ -963,6 +1038,8 @@ static int dsps_resume(struct device *dev)
 	if (!musb)
 		return 0;
 
+	dsps_dma_controller_resume(glue);
+
 	mbase = musb->ctrl_base;
 	musb_writel(mbase, wrp->control, glue->context.control);
 	musb_writel(mbase, wrp->epintr_set, glue->context.epintr);
-- 
1.9.1