Add support for USB3 snooping by asserting bits
in register DWC3_GSBUSCFG0 for data and descriptor.

Signed-off-by: Changming Huang <jerry.hu...@nxp.com>
Signed-off-by: Rajesh Bhagat <rajesh.bha...@nxp.com>
Signed-off-by: Ran Wang <ran.wan...@nxp.com>
---
 drivers/usb/dwc3/core.c | 24 ++++++++++++++++++++++++
 drivers/usb/dwc3/core.h | 10 ++++++++++
 2 files changed, 34 insertions(+)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 07832509584f..ffc078ab4a1c 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -236,6 +236,26 @@ static int dwc3_core_soft_reset(struct dwc3 *dwc)
        return -ETIMEDOUT;
 }
 
+/*
+ * dwc3_enable_snooping - Enable snooping feature
+ * @dwc3: Pointer to our controller context structure
+ */
+static void dwc3_enable_snooping(struct dwc3 *dwc)
+{
+       u32 cfg;
+
+       cfg = dwc3_readl(dwc->regs, DWC3_GSBUSCFG0);
+       if (dwc->dma_coherent) {
+               cfg &= ~DWC3_GSBUSCFG0_SNP_MASK;
+               cfg |= (AXI3_CACHE_TYPE_SNP << DWC3_GSBUSCFG0_DATARD_SHIFT) |
+                       (AXI3_CACHE_TYPE_SNP << DWC3_GSBUSCFG0_DESCRD_SHIFT) |
+                       (AXI3_CACHE_TYPE_SNP << DWC3_GSBUSCFG0_DATAWR_SHIFT) |
+                       (AXI3_CACHE_TYPE_SNP << DWC3_GSBUSCFG0_DESCWR_SHIFT);
+       }
+
+       dwc3_writel(dwc->regs, DWC3_GSBUSCFG0, cfg);
+}
+
 /*
  * dwc3_frame_length_adjustment - Adjusts frame length if required
  * @dwc3: Pointer to our controller context structure
@@ -776,6 +796,8 @@ static int dwc3_core_init(struct dwc3 *dwc)
        /* Adjust Frame Length */
        dwc3_frame_length_adjustment(dwc);
 
+       dwc3_enable_snooping(dwc);
+
        usb_phy_set_suspend(dwc->usb2_phy, 0);
        usb_phy_set_suspend(dwc->usb3_phy, 0);
        ret = phy_power_on(dwc->usb2_generic_phy);
@@ -1021,6 +1043,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
                                &hird_threshold);
        dwc->usb3_lpm_capable = device_property_read_bool(dev,
                                "snps,usb3_lpm_capable");
+       dwc->dma_coherent = device_property_read_bool(dev,
+                               "dma-coherent");
 
        dwc->disable_scramble_quirk = device_property_read_bool(dev,
                                "snps,disable_scramble_quirk");
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 4a4a4c98508c..6e6a66650e53 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -153,6 +153,14 @@
 
 /* Bit fields */
 
+/* Global SoC Bus Configuration Register 0 */
+#define AXI3_CACHE_TYPE_SNP            0x2 /* cacheable */
+#define DWC3_GSBUSCFG0_DATARD_SHIFT    28
+#define DWC3_GSBUSCFG0_DESCRD_SHIFT    24
+#define DWC3_GSBUSCFG0_DATAWR_SHIFT    20
+#define DWC3_GSBUSCFG0_DESCWR_SHIFT    16
+#define DWC3_GSBUSCFG0_SNP_MASK                0xffff0000
+
 /* Global Debug Queue/FIFO Space Available Register */
 #define DWC3_GDBGFIFOSPACE_NUM(n)      ((n) & 0x1f)
 #define DWC3_GDBGFIFOSPACE_TYPE(n)     (((n) << 5) & 0x1e0)
@@ -859,6 +867,7 @@ struct dwc3_scratchpad_array {
  *     3       - Reserved
  * @imod_interval: set the interrupt moderation interval in 250ns
  *                 increments or 0 to disable.
+ * @dma_coherent: set if enable dma-coherent.
  */
 struct dwc3 {
        struct work_struct      drd_work;
@@ -990,6 +999,7 @@ struct dwc3 {
        unsigned                setup_packet_pending:1;
        unsigned                three_stage_setup:1;
        unsigned                usb3_lpm_capable:1;
+       unsigned                dma_coherent:1;
 
        unsigned                disable_scramble_quirk:1;
        unsigned                u2exit_lfps_quirk:1;
-- 
2.14.1

Reply via email to