[PATCH v8 1/2] usb: dwc3: qcom: Add interconnect support in dwc3 driver

Sandeep Maheswaram
2020-07-09T16:00:55Z

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: Sandeep Maheswaram <sanm@codeaurora.org>
Signed-off-by: Chandana Kishori Chiluveru <cchiluve@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
---
drivers/usb/dwc3/dwc3-qcom.c | 127 ++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 125 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
index 1dfd024..5532988 100644
--- a/drivers/usb/dwc3/dwc3-qcom.c
+++ b/drivers/usb/dwc3/dwc3-qcom.c
@@ -13,6 +13,7 @@
#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>
@@ -43,6 +44,14 @@
#define SDM845_QSCRATCH_SIZE 0x400
#define SDM845_DWC3_CORE_SIZE 0xcd00

+/* 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)
+
struct dwc3_acpi_pdata {
u32 qscratch_base_offset;
u32 qscratch_base_size;
@@ -73,9 +82,12 @@ struct dwc3_qcom {

const struct dwc3_acpi_pdata *acpi_pdata;

+ enum usb_device_speed max_speed;
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 inline void dwc3_qcom_setbits(void __iomem *base, u32 offset, u32 val)
@@ -190,6 +202,99 @@ static int dwc3_qcom_register_extcon(struct dwc3_qcom *qcom)
return 0;
}

+/* Currently we only use bandwidth level, so just "enable" interconnects */
+static int dwc3_qcom_interconnect_enable(struct dwc3_qcom *qcom)
+{
+ int ret;
+
+ if (qcom->max_speed >= USB_SPEED_SUPER)
+ ret = icc_set_bw(qcom->usb_ddr_icc_path,
+ USB_MEMORY_AVG_SS_BW, USB_MEMORY_PEAK_SS_BW);
+ 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)
+ 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)
+{
+ 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:
+ dwc3_qcom_interconnect_enable(qcom);
+
+ return ret;
+}
+
+/**
+ * dwc3_qcom_interconnect_init() - Get interconnect path handles
+ * @qcom: Pointer to the concerned usb core.
+ *
+ */
+static int dwc3_qcom_interconnect_init(struct dwc3_qcom *qcom)
+{
+ struct device *dev = qcom->dev;
+ int ret;
+
+ if (!device_is_bound(&qcom->dwc3->dev))
+ 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);
+}
+
static void dwc3_qcom_disable_interrupts(struct dwc3_qcom *qcom)
{
if (qcom->hs_phy_irq) {
@@ -239,7 +344,7 @@ 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;
@@ -251,6 +356,10 @@ 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);

@@ -276,6 +385,10 @@ 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);
@@ -285,6 +398,8 @@ static int dwc3_qcom_resume(struct dwc3_qcom *qcom)
return 0;
}

+
+
static irqreturn_t qcom_dwc3_resume_irq(int irq, void *data)
{
struct dwc3_qcom *qcom = data;
@@ -648,6 +763,11 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
goto depopulate;
}

+ qcom->max_speed = usb_get_maximum_speed(&qcom->dwc3->dev);
+ ret = dwc3_qcom_interconnect_init(qcom);
+ if (ret)
+ goto depopulate;
+
qcom->mode = usb_get_dr_mode(&qcom->dwc3->dev);

/* enable vbus override for device mode */
@@ -657,7 +777,7 @@ 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;
@@ -667,6 +787,8 @@ static int dwc3_qcom_probe(struct platform_device *pdev)

return 0;

+interconnect_exit:
+ dwc3_qcom_interconnect_exit(qcom);
depopulate:
if (np)
of_platform_depopulate(&pdev->dev);
@@ -697,6 +819,7 @@ 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);