usb: dwc3: core: allocate scratch buffers

We must read HWPARAMS4 register to figure out
how many scratch buffers we should allocate.

Later patch will use "Set Scratchpad Buffer
Array" command to pass the pointer to the
IP so it can be used during hibernation.

Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 105 insertions, 0 deletions

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 785feeeac3c..8c627c9a513 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -242,6 +242,90 @@ static void dwc3_event_buffers_cleanup(struct dwc3 *dwc)
 	}
 }
 
+static int dwc3_alloc_scratch_buffers(struct dwc3 *dwc)
+{
+	if (!dwc->has_hibernation)
+		return 0;
+
+	if (!dwc->nr_scratch)
+		return 0;
+
+	dwc->scratchbuf = kmalloc_array(dwc->nr_scratch,
+			DWC3_SCRATCHBUF_SIZE, GFP_KERNEL);
+	if (!dwc->scratchbuf)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int dwc3_setup_scratch_buffers(struct dwc3 *dwc)
+{
+	dma_addr_t scratch_addr;
+	u32 param;
+	int ret;
+
+	if (!dwc->has_hibernation)
+		return 0;
+
+	if (!dwc->nr_scratch)
+		return 0;
+
+	 /* should never fall here */
+	if (!WARN_ON(dwc->scratchbuf))
+		return 0;
+
+	scratch_addr = dma_map_single(dwc->dev, dwc->scratchbuf,
+			dwc->nr_scratch * DWC3_SCRATCHBUF_SIZE,
+			DMA_BIDIRECTIONAL);
+	if (dma_mapping_error(dwc->dev, scratch_addr)) {
+		dev_err(dwc->dev, "failed to map scratch buffer\n");
+		ret = -EFAULT;
+		goto err0;
+	}
+
+	dwc->scratch_addr = scratch_addr;
+
+	param = lower_32_bits(scratch_addr);
+
+	ret = dwc3_send_gadget_generic_command(dwc,
+			DWC3_DGCMD_SET_SCRATCHPAD_ADDR_LO, param);
+	if (ret < 0)
+		goto err1;
+
+	param = upper_32_bits(scratch_addr);
+
+	ret = dwc3_send_gadget_generic_command(dwc,
+			DWC3_DGCMD_SET_SCRATCHPAD_ADDR_HI, param);
+	if (ret < 0)
+		goto err1;
+
+	return 0;
+
+err1:
+	dma_unmap_single(dwc->dev, dwc->scratch_addr, dwc->nr_scratch *
+			DWC3_SCRATCHBUF_SIZE, DMA_BIDIRECTIONAL);
+
+err0:
+	return ret;
+}
+
+static void dwc3_free_scratch_buffers(struct dwc3 *dwc)
+{
+	if (!dwc->has_hibernation)
+		return;
+
+	if (!dwc->nr_scratch)
+		return;
+
+	 /* should never fall here */
+	if (!WARN_ON(dwc->scratchbuf))
+		return;
+
+	dma_unmap_single(dwc->dev, dwc->scratch_addr, dwc->nr_scratch *
+			DWC3_SCRATCHBUF_SIZE, DMA_BIDIRECTIONAL);
+	kfree(dwc->scratchbuf);
+}
+
 static void dwc3_core_num_eps(struct dwc3 *dwc)
 {
 	struct dwc3_hwparams	*parms = &dwc->hwparams;
@@ -277,6 +361,7 @@ static void dwc3_cache_hwparams(struct dwc3 *dwc)
 static int dwc3_core_init(struct dwc3 *dwc)
 {
 	unsigned long		timeout;
+	u32			hwparams4 = dwc->hwparams.hwparams4;
 	u32			reg;
 	int			ret;
 
@@ -334,6 +419,10 @@ static int dwc3_core_init(struct dwc3 *dwc)
 		else
 			reg &= ~DWC3_GCTL_DSBLCLKGTNG;
 		break;
+	case DWC3_GHWPARAMS1_EN_PWROPT_HIB:
+		/* enable hibernation here */
+		dwc->nr_scratch = DWC3_GHWPARAMS4_HIBER_SCRATCHBUFS(hwparams4);
+		break;
 	default:
 		dev_dbg(dwc->dev, "No power optimization available\n");
 	}
@@ -351,14 +440,30 @@ static int dwc3_core_init(struct dwc3 *dwc)
 
 	dwc3_writel(dwc->regs, DWC3_GCTL, reg);
 
+	ret = dwc3_alloc_scratch_buffers(dwc);
+	if (ret)
+		goto err1;
+
+	ret = dwc3_setup_scratch_buffers(dwc);
+	if (ret)
+		goto err2;
+
 	return 0;
 
+err2:
+	dwc3_free_scratch_buffers(dwc);
+
+err1:
+	usb_phy_shutdown(dwc->usb2_phy);
+	usb_phy_shutdown(dwc->usb3_phy);
+
 err0:
 	return ret;
 }
 
 static void dwc3_core_exit(struct dwc3 *dwc)
 {
+	dwc3_free_scratch_buffers(dwc);
 	usb_phy_shutdown(dwc->usb2_phy);
 	usb_phy_shutdown(dwc->usb3_phy);
 }