[ALPS07777697] USB Offload: modify mode determination

When kernel enters suspend mode, we should reply the current mode
to mtu3 drivers. If one of the low-power-related structure falls
to reserved dram, even its in advanced mode, APSRC request
should not be released.

Add a list to store the buffer which indicating structure that
fell into reserved dram and check if its empty when mtu3 is
requesting for current mode.

MTK-Commit-Id: 87c2807e30cedc05279647aae3e91cb5ae3b0540

Signed-off-by: Jason Liu <[email protected]>
CR-Id: ALPS07777697
Feature: USB type C audio offload
Change-Id: Ia161deeac74a334205d038f4f833d4338e84858e

drivers/misc/mediatek/usb/usb_offload/usb_offload.h

@@ -60,6 +60,7 @@ struct usb_offload_buffer {
 	bool is_sram;
 	bool is_rsv;
 	u8 type;
+	struct list_head list;
 };
 
 enum usb_offload_mem_id {
@@ -270,7 +271,7 @@ extern int mtk_usb_offload_deinit_rsv_sram(void);
 extern int mtk_offload_alloc_mem(struct usb_offload_buffer *buf, unsigned int size,
 	int align, enum usb_offload_mem_id mem_id, bool is_rsv);
 extern int mtk_offload_free_mem(struct usb_offload_buffer *buf);
-extern bool mtk_offload_is_sram_mode(void);
+extern bool mtk_offload_is_advlowpwr(struct usb_offload_dev *udev);
 extern int mtk_offload_get_rsv_mem_info(enum usb_offload_mem_id mem_id,
 	unsigned int *phys, unsigned int *size);
 extern bool is_sram(enum usb_offload_mem_id id);

drivers/misc/mediatek/usb/usb_offload/usb_offload_common.c

@@ -2354,16 +2354,19 @@ static struct xhci_vendor_ops xhci_mtk_vendor_ops = {
 
 int xhci_mtk_ssusb_offload_get_mode(struct device *dev)
 {
-	bool is_sram_mode;
+	bool is_in_advanced;
 
-	is_sram_mode = mtk_offload_is_sram_mode();
-	USB_OFFLOAD_INFO("is_streaming:%d, is_sram_mode:%d\n",
-		uodev->is_streaming, is_sram_mode);
+	is_in_advanced = mtk_offload_is_advlowpwr(uodev);
+	USB_OFFLOAD_INFO("is_streaming:%d, is_in_advanced:%d\n",
+		uodev->is_streaming, is_in_advanced);
 
 	if (!uodev->is_streaming)
 		return SSUSB_OFFLOAD_MODE_NONE;
 
-	return is_sram_mode ? SSUSB_OFFLOAD_MODE_S : SSUSB_OFFLOAD_MODE_D;
+	/* we only release APSRC request in advanced mode by
+	 * notifying SSUSB_OFFLOAD_MODE_S to mtu3 driver
+	 */
+	return is_in_advanced ? SSUSB_OFFLOAD_MODE_S : SSUSB_OFFLOAD_MODE_D;
 }
 
 static int usb_offload_probe(struct platform_device *pdev)

drivers/misc/mediatek/usb/usb_offload/usb_offload_mem.c

@@ -39,7 +39,38 @@ static struct mtk_sram_pwr sram_pwr[MEM_TYPE_NUM];
 
 struct usb_offload_mem_info usb_offload_mem_buffer[USB_OFFLOAD_MEM_NUM];
 
+/* a list to store buffer which downgrade from sram to dram */
+LIST_HEAD(downgrade_list);
 
+static bool is_buf_downgrade(struct usb_offload_buffer *buf)
+{
+	struct usb_offload_buffer *pos;
+	bool found = false;
+
+	list_for_each_entry(pos, &downgrade_list, list) {
+		if (pos == buf) {
+			found = true;
+			break;
+		}
+	}
+
+	return found;
+}
+
+bool mtk_offload_is_advlowpwr(struct usb_offload_dev *udev)
+{
+	/* if adv_lowpwr is false, it means that either sram feature is
+	 * disabled in dts or basic sram is not supported in this platform.
+	 */
+	if (!udev->adv_lowpwr)
+		return false;
+
+	/* if list is empty, it means no structure falls to dram,
+	 * so it's in advanced mode, in an other hands, it's basic
+	 */
+	return list_empty(&downgrade_list);
+}
+EXPORT_SYMBOL_GPL(mtk_offload_is_advlowpwr);
 
 static void reset_buffer(struct usb_offload_buffer *buf)
 {
@@ -103,20 +134,6 @@ int mtk_offload_get_rsv_mem_info(enum usb_offload_mem_id mem_id,
 }
 EXPORT_SYMBOL_GPL(mtk_offload_get_rsv_mem_info);
 
-bool mtk_offload_is_sram_mode(void)
-{
-#ifdef MTK_AUDIO_INTERFACE_READY
-	u32 i;
-
-	for (i = 0; i < MEM_TYPE_NUM; i++) {
-		if (atomic_read(&sram_pwr[i].cnt))
-			return true;
-	}
-#endif
-	return false;
-}
-EXPORT_SYMBOL_GPL(mtk_offload_is_sram_mode);
-
 bool is_sram(enum usb_offload_mem_id id)
 {
 	return id == USB_OFFLOAD_MEM_SRAM_ID ? true : false;
@@ -531,6 +548,12 @@ int mtk_offload_alloc_mem(struct usb_offload_buffer *buf,
 		goto ALLOC_FAIL;
 
 ALLOC_SUCCESS:
+	if (is_sram(mem_id) && !buf->is_sram) {
+		/* we requeset for sram, but turn out to be dram */
+		USB_OFFLOAD_INFO("buf:%p falls from sram to dram\n", buf);
+		list_add_tail(&buf->list, &downgrade_list);
+	}
+
 	USB_OFFLOAD_INFO("va:%p phy:0x%llx size:%zu is_sram:%d is_rsv:%d type:%s\n",
 		buf->dma_area, (unsigned long long)buf->dma_addr,
 		buf->dma_bytes, buf->is_sram, buf->is_rsv,
@@ -565,8 +588,13 @@ int mtk_offload_free_mem(struct usb_offload_buffer *buf)
 	type = buf->type;
 	is_sram = buf->is_sram;
 
-	if (!buf->is_sram)
+	if (!buf->is_sram) {
 		ret = mtk_usb_offload_free_rsv_mem(buf, USB_OFFLOAD_MEM_DRAM_ID);
+
+		if (is_buf_downgrade(buf))
+			list_del(&buf->list);
+
+	}
 	else if (uodev->adv_lowpwr) {
 		if (buf->is_rsv)
 			ret = mtk_usb_offload_free_rsv_mem(buf, USB_OFFLOAD_MEM_SRAM_ID);