From: Chandana Kishori Chiluveru <cchil...@codeaurora.org>

Add interconnect support in dwc3-qcom driver to vote for bus
bandwidth.

This requires for two different paths - from USB master to
DDR slave. The other is from APPS master to USB slave.

Signed-off-by: Chandana Kishori Chiluveru <cchil...@codeaurora.org>
---
 drivers/usb/dwc3/dwc3-qcom.c | 145 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 143 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
index 184df4d..3a540f7 100644
--- a/drivers/usb/dwc3/dwc3-qcom.c
+++ b/drivers/usb/dwc3/dwc3-qcom.c
@@ -12,6 +12,7 @@
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/extcon.h>
+#include <linux/interconnect.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/phy/phy.h>
@@ -59,8 +60,13 @@ struct dwc3_qcom {
        enum usb_dr_mode        mode;
        bool                    is_suspended;
        bool                    pm_suspended;
+       struct icc_path         *usb_ddr_icc_path;
+       struct icc_path         *apps_usb_icc_path;
 };
 
+static int dwc3_qcom_interconnect_enable(struct dwc3_qcom *qcom);
+static int dwc3_qcom_interconnect_disable(struct dwc3_qcom *qcom);
+
 static inline void dwc3_qcom_setbits(void __iomem *base, u32 offset, u32 val)
 {
        u32 reg;
@@ -222,7 +228,7 @@ static void dwc3_qcom_enable_interrupts(struct dwc3_qcom 
*qcom)
 static int dwc3_qcom_suspend(struct dwc3_qcom *qcom)
 {
        u32 val;
-       int i;
+       int i, ret;
 
        if (qcom->is_suspended)
                return 0;
@@ -234,6 +240,10 @@ static int dwc3_qcom_suspend(struct dwc3_qcom *qcom)
        for (i = qcom->num_clocks - 1; i >= 0; i--)
                clk_disable_unprepare(qcom->clks[i]);
 
+       ret = dwc3_qcom_interconnect_disable(qcom);
+       if (ret)
+               dev_warn(qcom->dev, "failed to disable interconnect %d\n", ret);
+
        qcom->is_suspended = true;
        dwc3_qcom_enable_interrupts(qcom);
 
@@ -259,6 +269,10 @@ static int dwc3_qcom_resume(struct dwc3_qcom *qcom)
                }
        }
 
+       ret = dwc3_qcom_interconnect_enable(qcom);
+       if (ret)
+               dev_warn(qcom->dev, "failed to enable interconnect %d\n", ret);
+
        /* Clear existing events from PHY related to L2 in/out */
        dwc3_qcom_setbits(qcom->qscratch_base, PWR_EVNT_IRQ_STAT_REG,
                          PWR_EVNT_LPM_IN_L2_MASK | PWR_EVNT_LPM_OUT_L2_MASK);
@@ -268,6 +282,124 @@ static int dwc3_qcom_resume(struct dwc3_qcom *qcom)
        return 0;
 }
 
+/* Interconnect path bandwidths in MBps */
+#define USB_MEMORY_AVG_HS_BW MBps_to_icc(240)
+#define USB_MEMORY_PEAK_HS_BW MBps_to_icc(700)
+#define USB_MEMORY_AVG_SS_BW  MBps_to_icc(1000)
+#define USB_MEMORY_PEAK_SS_BW MBps_to_icc(2500)
+#define APPS_USB_AVG_BW 0
+#define APPS_USB_PEAK_BW MBps_to_icc(40)
+
+/**
+ * dwc3_qcom_interconnect_init() - Initialize the interconnect
+ * @qcom:                      Pointer to the concerned usb core.
+ *
+ */
+static int dwc3_qcom_interconnect_init(struct dwc3_qcom *qcom)
+{
+       struct device *dev = qcom->dev;
+       struct dwc3 *dwc;
+       int ret;
+
+       if (!device_is_bound(&qcom->dwc3->dev)) {
+               dev_err(qcom->dev, "device is not bound\n");
+               return -EPROBE_DEFER;
+       }
+
+       qcom->usb_ddr_icc_path = of_icc_get(dev, "usb-ddr");
+       if (IS_ERR(qcom->usb_ddr_icc_path)) {
+               dev_err(dev, "Error: (%ld) failed getting usb-ddr path\n",
+                       PTR_ERR(qcom->usb_ddr_icc_path));
+               return PTR_ERR(qcom->usb_ddr_icc_path);
+       }
+
+       qcom->apps_usb_icc_path = of_icc_get(dev, "apps-usb");
+       if (IS_ERR(qcom->apps_usb_icc_path)) {
+               dev_err(dev, "Error: (%ld) failed getting apps-usb path\n",
+                               PTR_ERR(qcom->apps_usb_icc_path));
+               return PTR_ERR(qcom->apps_usb_icc_path);
+       }
+
+       ret = dwc3_qcom_interconnect_enable(qcom);
+       if (ret) {
+               dev_err(dev, "failed to enable interconnect: %d\n", ret);
+               return ret;
+       }
+
+       return 0;
+}
+
+/**
+ * dwc3_qcom_interconnect_exit() - Release interconnect path handles
+ * @qcom:                      Pointer to the concerned usb core.
+ *
+ * This function is used to release interconnect path handle.
+ */
+static void dwc3_qcom_interconnect_exit(struct dwc3_qcom *qcom)
+{
+       icc_put(qcom->usb_ddr_icc_path);
+       icc_put(qcom->apps_usb_icc_path);
+}
+
+/* Currently we only use bandwidth level, so just "enable" interconnects */
+static int dwc3_qcom_interconnect_enable(struct dwc3_qcom *qcom)
+{
+       struct dwc3 *dwc = platform_get_drvdata(qcom->dwc3);
+       int ret;
+
+       if (dwc->maximum_speed == USB_SPEED_SUPER) {
+               ret = icc_set_bw(qcom->usb_ddr_icc_path,
+                       USB_MEMORY_AVG_SS_BW, USB_MEMORY_PEAK_SS_BW);
+               if (ret)
+                       return ret;
+       } else {
+               ret = icc_set_bw(qcom->usb_ddr_icc_path,
+                       USB_MEMORY_AVG_HS_BW, USB_MEMORY_PEAK_HS_BW);
+               if (ret)
+                       return ret;
+       }
+
+       ret = icc_set_bw(qcom->apps_usb_icc_path,
+               APPS_USB_AVG_BW, APPS_USB_PEAK_BW);
+       if (ret)
+               goto err_disable_mem_path;
+
+       return 0;
+
+err_disable_mem_path:
+       icc_set_bw(qcom->usb_ddr_icc_path, 0, 0);
+
+       return ret;
+}
+
+/* To disable an interconnect, we just set its bandwidth to 0 */
+static int dwc3_qcom_interconnect_disable(struct dwc3_qcom *qcom)
+{
+       struct dwc3 *dwc = platform_get_drvdata(qcom->dwc3);
+       int ret;
+
+       ret = icc_set_bw(qcom->usb_ddr_icc_path, 0, 0);
+       if (ret)
+               return ret;
+
+       ret = icc_set_bw(qcom->apps_usb_icc_path, 0, 0);
+       if (ret)
+               goto err_reenable_memory_path;
+
+       return 0;
+
+       /* Re-enable things in the event of an error */
+err_reenable_memory_path:
+       if (dwc->maximum_speed == USB_SPEED_SUPER)
+               icc_set_bw(qcom->usb_ddr_icc_path,
+                       USB_MEMORY_AVG_SS_BW, USB_MEMORY_PEAK_SS_BW);
+       else
+               icc_set_bw(qcom->usb_ddr_icc_path,
+                       USB_MEMORY_AVG_HS_BW, USB_MEMORY_PEAK_HS_BW);
+
+       return ret;
+}
+
 static irqreturn_t qcom_dwc3_resume_irq(int irq, void *data)
 {
        struct dwc3_qcom *qcom = data;
@@ -494,6 +626,12 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
                goto depopulate;
        }
 
+       ret = dwc3_qcom_interconnect_init(qcom);
+       if (ret) {
+               dev_err(dev, "failed to init interconnect: %d\n", ret);
+               goto depopulate;
+       }
+
        qcom->mode = usb_get_dr_mode(&qcom->dwc3->dev);
 
        /* enable vbus override for device mode */
@@ -503,7 +641,7 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
        /* register extcon to override sw_vbus on Vbus change later */
        ret = dwc3_qcom_register_extcon(qcom);
        if (ret)
-               goto depopulate;
+               goto interconnect_exit;
 
        device_init_wakeup(&pdev->dev, 1);
        qcom->is_suspended = false;
@@ -513,6 +651,8 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
 
        return 0;
 
+interconnect_exit:
+       dwc3_qcom_interconnect_exit(qcom);
 depopulate:
        of_platform_depopulate(&pdev->dev);
 clk_disable:
@@ -540,6 +680,7 @@ static int dwc3_qcom_remove(struct platform_device *pdev)
        }
        qcom->num_clocks = 0;
 
+       dwc3_qcom_interconnect_exit(qcom);
        reset_control_assert(qcom->resets);
 
        pm_runtime_allow(dev);
-- 
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