[PATCH 2/3] usb: dwc3: qcom: Add interconnect support in dwc3 driver

Chandana Kishori Chiluveru
2019-09-11T04:55:05Z

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 <cchiluve@codeaurora.org>
---
drivers/usb/dwc3/dwc3-qcom.c | 147 ++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 145 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
index 184df4d..4b8c2ae 100644
--- a/drivers/usb/dwc3/dwc3-qcom.c
+++ b/drivers/usb/dwc3/dwc3-qcom.c
@@ -14,6 +14,7 @@
#include <linux/extcon.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
+#include <linux/interconnect.h>
#include <linux/phy/phy.h>
#include <linux/usb/of.h>
#include <linux/reset.h>
@@ -38,6 +39,9 @@
#define PWR_EVNT_LPM_IN_L2_MASK BIT(4)
#define PWR_EVNT_LPM_OUT_L2_MASK BIT(5)

+#define USB_DDR "usb-ddr"
+#define APPS_USB "apps-usb"
+
struct dwc3_qcom {
struct device *dev;
void __iomem *qscratch_base;
@@ -59,8 +63,13 @@ 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 usb_interconnect_enable(struct dwc3_qcom *qcom);
+static int usb_interconnect_disable(struct dwc3_qcom *qcom);
+
static inline void dwc3_qcom_setbits(void __iomem *base, u32 offset, u32 val)
{
u32 reg;
@@ -222,7 +231,7 @@ 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 +243,11 @@ static int dwc3_qcom_suspend(struct dwc3_qcom *qcom)
for (i = qcom->num_clocks - 1; i >= 0; i--)
clk_disable_unprepare(qcom->clks[i]);

+ /* Remove bus voting */
+ ret = usb_interconnect_disable(qcom);
+ if (ret)
+ dev_err(qcom->dev, "bus bw voting failed %d\n", ret);
+
qcom->is_suspended = true;
dwc3_qcom_enable_interrupts(qcom);

@@ -259,6 +273,11 @@ static int dwc3_qcom_resume(struct dwc3_qcom *qcom)
}
}

+ /* Add bus voting */
+ ret = usb_interconnect_enable(qcom);
+ if (ret)
+ dev_err(qcom->dev, "bus bw voting failed %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);
@@ -409,6 +428,116 @@ static int dwc3_qcom_clk_init(struct dwc3_qcom *qcom, int count)
return 0;
}

+/* Interconnect path bandwidths in KBps */
+#define USB_MEMORY_AVG_HS_BW 240000
+#define USB_MEMORY_PEAK_HS_BW 700000
+#define USB_MEMORY_AVG_SS_BW 1000000
+#define USB_MEMORY_PEAK_SS_BW 2500000
+#define APPS_USB_AVG_BW 0
+#define APPS_USB_PEAK_BW 40000
+
+/**
+ * usb_interconnect_init() - Request to get interconnect path handle
+ * @qcom: Pointer to the concerned usb core.
+ *
+ */
+static int usb_interconnect_init(struct dwc3_qcom *qcom)
+{
+ struct device *dev = qcom->dev;
+
+ 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 %s path\n",
+ PTR_ERR(qcom->usb_ddr_icc_path), USB_DDR);
+ 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 %s path\n",
+ PTR_ERR(qcom->apps_usb_icc_path), APPS_USB);
+ return PTR_ERR(qcom->usb_ddr_icc_path);
+ }
+
+ return 0;
+}
+
+/**
+ * geni_interconnect_exit() - Request to release interconnect path handle
+ * @qcom: Pointer to the concerned usb core.
+ *
+ * This function is used to release interconnect path handle.
+ */
+static void usb_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 usb_interconnect_enable(struct dwc3_qcom *qcom)
+{
+ struct dwc3 *dwc;
+ int ret;
+
+ dwc = platform_get_drvdata(qcom->dwc3);
+ if (!dwc) {
+ dev_err(qcom->dev, "Failed to get dwc3 device\n");
+ return -EPROBE_DEFER;
+ }
+
+ 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 its bandwidth to 0 */
+static int usb_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; /* Success */
+
+ /* 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 int dwc3_qcom_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node, *dwc3_np;
@@ -494,6 +623,17 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
goto depopulate;
}

+ ret = usb_interconnect_init(qcom);
+ if (ret) {
+ dev_err(dev, "failed to get interconnect handle ret:%d\n", ret);
+ goto depopulate;
+ }
+ ret = usb_interconnect_enable(qcom);
+ if (ret) {
+ dev_err(qcom->dev, "bus bw voting failed %d\n", ret);
+ goto interconnect_exit;
+ }
+
qcom->mode = usb_get_dr_mode(&qcom->dwc3->dev);

/* enable vbus override for device mode */
@@ -503,7 +643,7 @@ 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 +653,8 @@ static int dwc3_qcom_probe(struct platform_device *pdev)

return 0;

+interconnect_exit:
+ usb_interconnect_exit(qcom);
depopulate:
of_platform_depopulate(&pdev->dev);
clk_disable:
@@ -540,6 +682,7 @@ static int dwc3_qcom_remove(struct platform_device *pdev)
}
qcom->num_clocks = 0;

+ usb_interconnect_exit(qcom);
reset_control_assert(qcom->resets);

pm_runtime_allow(dev);