USB: OTG: msm: Add support for power management
Implement runtime and system pm ops to put hardware into low power
mode (LPM). As part of LPM, USB clocks are turned off, PHY is put
into suspend state and PHY comparators are turned off if VBUS/Id
notifications are not required from PHY.
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/otg/Kconfig b/drivers/usb/otg/Kconfig
index 915c729..2810c2a 100644
--- a/drivers/usb/otg/Kconfig
+++ b/drivers/usb/otg/Kconfig
@@ -88,7 +88,8 @@
help
Enable this to support the USB OTG transceiver on MSM chips. It
handles PHY initialization, clock management, and workarounds
- required after resetting the hardware. This driver is required
- even for peripheral only or host only mode configuration.
+ required after resetting the hardware and power management.
+ This driver is required even for peripheral only or host only
+ mode configurations.
endif # USB || OTG
diff --git a/drivers/usb/otg/msm72k_otg.c b/drivers/usb/otg/msm72k_otg.c
index 46f468a..1cd52ed 100644
--- a/drivers/usb/otg/msm72k_otg.c
+++ b/drivers/usb/otg/msm72k_otg.c
@@ -29,6 +29,7 @@
#include <linux/uaccess.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
+#include <linux/pm_runtime.h>
#include <linux/usb.h>
#include <linux/usb/otg.h>
@@ -251,6 +252,154 @@
return 0;
}
+#define PHY_SUSPEND_TIMEOUT_USEC (500 * 1000)
+static int msm_otg_suspend(struct msm_otg *motg)
+{
+ struct otg_transceiver *otg = &motg->otg;
+ struct usb_bus *bus = otg->host;
+ struct msm_otg_platform_data *pdata = motg->pdata;
+ int cnt = 0;
+
+ if (atomic_read(&motg->in_lpm))
+ return 0;
+
+ disable_irq(motg->irq);
+ /*
+ * Interrupt Latch Register auto-clear feature is not present
+ * in all PHY versions. Latch register is clear on read type.
+ * Clear latch register to avoid spurious wakeup from
+ * low power mode (LPM).
+ */
+ ulpi_read(otg, 0x14);
+
+ /*
+ * PHY comparators are disabled when PHY enters into low power
+ * mode (LPM). Keep PHY comparators ON in LPM only when we expect
+ * VBUS/Id notifications from USB PHY. Otherwise turn off USB
+ * PHY comparators. This save significant amount of power.
+ */
+ if (pdata->otg_control == OTG_PHY_CONTROL)
+ ulpi_write(otg, 0x01, 0x30);
+
+ /*
+ * PLL is not turned off when PHY enters into low power mode (LPM).
+ * Disable PLL for maximum power savings.
+ */
+ ulpi_write(otg, 0x08, 0x09);
+
+ /*
+ * PHY may take some time or even fail to enter into low power
+ * mode (LPM). Hence poll for 500 msec and reset the PHY and link
+ * in failure case.
+ */
+ writel(readl(USB_PORTSC) | PORTSC_PHCD, USB_PORTSC);
+ while (cnt < PHY_SUSPEND_TIMEOUT_USEC) {
+ if (readl(USB_PORTSC) & PORTSC_PHCD)
+ break;
+ udelay(1);
+ cnt++;
+ }
+
+ if (cnt >= PHY_SUSPEND_TIMEOUT_USEC) {
+ dev_err(otg->dev, "Unable to suspend PHY\n");
+ msm_otg_reset(otg);
+ enable_irq(motg->irq);
+ return -ETIMEDOUT;
+ }
+
+ /*
+ * PHY has capability to generate interrupt asynchronously in low
+ * power mode (LPM). This interrupt is level triggered. So USB IRQ
+ * line must be disabled till async interrupt enable bit is cleared
+ * in USBCMD register. Assert STP (ULPI interface STOP signal) to
+ * block data communication from PHY.
+ */
+ writel(readl(USB_USBCMD) | ASYNC_INTR_CTRL | ULPI_STP_CTRL, USB_USBCMD);
+
+ clk_disable(motg->pclk);
+ clk_disable(motg->clk);
+ if (motg->core_clk)
+ clk_disable(motg->core_clk);
+
+ if (device_may_wakeup(otg->dev))
+ enable_irq_wake(motg->irq);
+ if (bus)
+ clear_bit(HCD_FLAG_HW_ACCESSIBLE, &(bus_to_hcd(bus))->flags);
+
+ atomic_set(&motg->in_lpm, 1);
+ enable_irq(motg->irq);
+
+ dev_info(otg->dev, "USB in low power mode\n");
+
+ return 0;
+}
+
+#define PHY_RESUME_TIMEOUT_USEC (100 * 1000)
+static int msm_otg_resume(struct msm_otg *motg)
+{
+ struct otg_transceiver *otg = &motg->otg;
+ struct usb_bus *bus = otg->host;
+ int cnt = 0;
+ unsigned temp;
+
+ if (!atomic_read(&motg->in_lpm))
+ return 0;
+
+ clk_enable(motg->pclk);
+ clk_enable(motg->clk);
+ if (motg->core_clk)
+ clk_enable(motg->core_clk);
+
+ temp = readl(USB_USBCMD);
+ temp &= ~ASYNC_INTR_CTRL;
+ temp &= ~ULPI_STP_CTRL;
+ writel(temp, USB_USBCMD);
+
+ /*
+ * PHY comes out of low power mode (LPM) in case of wakeup
+ * from asynchronous interrupt.
+ */
+ if (!(readl(USB_PORTSC) & PORTSC_PHCD))
+ goto skip_phy_resume;
+
+ writel(readl(USB_PORTSC) & ~PORTSC_PHCD, USB_PORTSC);
+ while (cnt < PHY_RESUME_TIMEOUT_USEC) {
+ if (!(readl(USB_PORTSC) & PORTSC_PHCD))
+ break;
+ udelay(1);
+ cnt++;
+ }
+
+ if (cnt >= PHY_RESUME_TIMEOUT_USEC) {
+ /*
+ * This is a fatal error. Reset the link and
+ * PHY. USB state can not be restored. Re-insertion
+ * of USB cable is the only way to get USB working.
+ */
+ dev_err(otg->dev, "Unable to resume USB."
+ "Re-plugin the cable\n");
+ msm_otg_reset(otg);
+ }
+
+skip_phy_resume:
+ if (device_may_wakeup(otg->dev))
+ disable_irq_wake(motg->irq);
+ if (bus)
+ set_bit(HCD_FLAG_HW_ACCESSIBLE, &(bus_to_hcd(bus))->flags);
+
+ if (motg->async_int) {
+ motg->async_int = 0;
+ pm_runtime_put(otg->dev);
+ enable_irq(motg->irq);
+ }
+
+ atomic_set(&motg->in_lpm, 0);
+
+ dev_info(otg->dev, "USB exited from low power mode\n");
+
+ return 0;
+}
+
static void msm_otg_start_host(struct otg_transceiver *otg, int on)
{
struct msm_otg *motg = container_of(otg, struct msm_otg, otg);
@@ -306,6 +455,7 @@
if (!host) {
if (otg->state == OTG_STATE_A_HOST) {
+ pm_runtime_get_sync(otg->dev);
msm_otg_start_host(otg, 0);
otg->host = NULL;
otg->state = OTG_STATE_UNDEFINED;
@@ -327,8 +477,10 @@
* Kick the state machine work, if peripheral is not supported
* or peripheral is already registered with us.
*/
- if (motg->pdata->mode == USB_HOST || otg->gadget)
+ if (motg->pdata->mode == USB_HOST || otg->gadget) {
+ pm_runtime_get_sync(otg->dev);
schedule_work(&motg->sm_work);
+ }
return 0;
}
@@ -376,6 +528,7 @@
if (!gadget) {
if (otg->state == OTG_STATE_B_PERIPHERAL) {
+ pm_runtime_get_sync(otg->dev);
msm_otg_start_peripheral(otg, 0);
otg->gadget = NULL;
otg->state = OTG_STATE_UNDEFINED;
@@ -393,8 +546,10 @@
* Kick the state machine work, if host is not supported
* or host is already registered with us.
*/
- if (motg->pdata->mode == USB_PERIPHERAL || otg->host)
+ if (motg->pdata->mode == USB_PERIPHERAL || otg->host) {
+ pm_runtime_get_sync(otg->dev);
schedule_work(&motg->sm_work);
+ }
return 0;
}
@@ -473,6 +628,7 @@
msm_otg_start_peripheral(otg, 1);
otg->state = OTG_STATE_B_PERIPHERAL;
}
+ pm_runtime_put_sync(otg->dev);
break;
case OTG_STATE_B_PERIPHERAL:
dev_dbg(otg->dev, "OTG_STATE_B_PERIPHERAL state\n");
@@ -504,6 +660,13 @@
struct otg_transceiver *otg = &motg->otg;
u32 otgsc = 0;
+ if (atomic_read(&motg->in_lpm)) {
+ disable_irq_nosync(irq);
+ motg->async_int = 1;
+ pm_runtime_get(otg->dev);
+ return IRQ_HANDLED;
+ }
+
otgsc = readl(USB_OTGSC);
if (!(otgsc & (OTGSC_IDIS | OTGSC_BSVIS)))
return IRQ_NONE;
@@ -514,12 +677,14 @@
else
clear_bit(ID, &motg->inputs);
dev_dbg(otg->dev, "ID set/clear\n");
+ pm_runtime_get_noresume(otg->dev);
} else if ((otgsc & OTGSC_BSVIS) && (otgsc & OTGSC_BSVIE)) {
if (otgsc & OTGSC_BSV)
set_bit(B_SESS_VLD, &motg->inputs);
else
clear_bit(B_SESS_VLD, &motg->inputs);
dev_dbg(otg->dev, "BSV set/clear\n");
+ pm_runtime_get_noresume(otg->dev);
}
writel(otgsc, USB_OTGSC);
@@ -616,6 +781,7 @@
goto out;
}
+ pm_runtime_get_sync(otg->dev);
schedule_work(&motg->sm_work);
out:
return status;
@@ -770,8 +936,10 @@
"not available\n");
}
- return 0;
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+ return 0;
free_irq:
free_irq(motg->irq, motg);
disable_clks:
@@ -796,23 +964,45 @@
{
struct msm_otg *motg = platform_get_drvdata(pdev);
struct otg_transceiver *otg = &motg->otg;
+ int cnt = 0;
if (otg->host || otg->gadget)
return -EBUSY;
msm_otg_debugfs_cleanup();
cancel_work_sync(&motg->sm_work);
- device_init_wakeup(&pdev->dev, 0);
- otg_set_transceiver(NULL);
+ msm_otg_resume(motg);
+
+ device_init_wakeup(&pdev->dev, 0);
+ pm_runtime_disable(&pdev->dev);
+
+ otg_set_transceiver(NULL);
free_irq(motg->irq, motg);
+ /*
+ * Put PHY in low power mode.
+ */
+ ulpi_read(otg, 0x14);
+ ulpi_write(otg, 0x08, 0x09);
+
+ writel(readl(USB_PORTSC) | PORTSC_PHCD, USB_PORTSC);
+ while (cnt < PHY_SUSPEND_TIMEOUT_USEC) {
+ if (readl(USB_PORTSC) & PORTSC_PHCD)
+ break;
+ udelay(1);
+ cnt++;
+ }
+ if (cnt >= PHY_SUSPEND_TIMEOUT_USEC)
+ dev_err(otg->dev, "Unable to suspend PHY\n");
+
clk_disable(motg->pclk);
clk_disable(motg->clk);
if (motg->core_clk)
clk_disable(motg->core_clk);
iounmap(motg->regs);
+ pm_runtime_set_suspended(&pdev->dev);
clk_put(motg->phy_reset_clk);
clk_put(motg->pclk);
@@ -825,11 +1015,96 @@
return 0;
}
+#ifdef CONFIG_PM_RUNTIME
+static int msm_otg_runtime_idle(struct device *dev)
+{
+ struct msm_otg *motg = dev_get_drvdata(dev);
+ struct otg_transceiver *otg = &motg->otg;
+
+ dev_dbg(dev, "OTG runtime idle\n");
+
+ /*
+ * It is observed some times that a spurious interrupt
+ * comes when PHY is put into LPM immediately after PHY reset.
+ * This 1 sec delay also prevents entering into LPM immediately
+ * after asynchronous interrupt.
+ */
+ if (otg->state != OTG_STATE_UNDEFINED)
+ pm_schedule_suspend(dev, 1000);
+
+ return -EAGAIN;
+}
+
+static int msm_otg_runtime_suspend(struct device *dev)
+{
+ struct msm_otg *motg = dev_get_drvdata(dev);
+
+ dev_dbg(dev, "OTG runtime suspend\n");
+ return msm_otg_suspend(motg);
+}
+
+static int msm_otg_runtime_resume(struct device *dev)
+{
+ struct msm_otg *motg = dev_get_drvdata(dev);
+
+ dev_dbg(dev, "OTG runtime resume\n");
+ return msm_otg_resume(motg);
+}
+#else
+#define msm_otg_runtime_idle NULL
+#define msm_otg_runtime_suspend NULL
+#define msm_otg_runtime_resume NULL
+#endif
+
+#ifdef CONFIG_PM
+static int msm_otg_pm_suspend(struct device *dev)
+{
+ struct msm_otg *motg = dev_get_drvdata(dev);
+
+ dev_dbg(dev, "OTG PM suspend\n");
+ return msm_otg_suspend(motg);
+}
+
+static int msm_otg_pm_resume(struct device *dev)
+{
+ struct msm_otg *motg = dev_get_drvdata(dev);
+ int ret;
+
+ dev_dbg(dev, "OTG PM resume\n");
+
+ ret = msm_otg_resume(motg);
+ if (ret)
+ return ret;
+
+ /*
+ * Runtime PM Documentation recommends bringing the
+ * device to full powered state upon resume.
+ */
+ pm_runtime_disable(dev);
+ pm_runtime_set_active(dev);
+ pm_runtime_enable(dev);
+
+ return 0;
+}
+#else
+#define msm_otg_pm_suspend NULL
+#define msm_otg_pm_resume NULL
+#endif
+
+static const struct dev_pm_ops msm_otg_dev_pm_ops = {
+ .runtime_suspend = msm_otg_runtime_suspend,
+ .runtime_resume = msm_otg_runtime_resume,
+ .runtime_idle = msm_otg_runtime_idle,
+ .suspend = msm_otg_pm_suspend,
+ .resume = msm_otg_pm_resume,
+};
+
static struct platform_driver msm_otg_driver = {
.remove = __devexit_p(msm_otg_remove),
.driver = {
.name = DRIVER_NAME,
.owner = THIS_MODULE,
+ .pm = &msm_otg_dev_pm_ops,
},
};
diff --git a/include/linux/usb/msm_hsusb.h b/include/linux/usb/msm_hsusb.h
index b796df9..3675e03 100644
--- a/include/linux/usb/msm_hsusb.h
+++ b/include/linux/usb/msm_hsusb.h
@@ -88,6 +88,8 @@
* @regs: ioremapped register base address.
* @inputs: OTG state machine inputs(Id, SessValid etc).
* @sm_work: OTG state machine work.
+ * @in_lpm: indicates low power mode (LPM) state.
+ * @async_int: Async interrupt arrived.
*
*/
struct msm_otg {
@@ -103,6 +105,8 @@
#define B_SESS_VLD 1
unsigned long inputs;
struct work_struct sm_work;
+ atomic_t in_lpm;
+ int async_int;
};
#endif
diff --git a/include/linux/usb/msm_hsusb_hw.h b/include/linux/usb/msm_hsusb_hw.h
index b061cff..b92e173 100644
--- a/include/linux/usb/msm_hsusb_hw.h
+++ b/include/linux/usb/msm_hsusb_hw.h
@@ -44,6 +44,9 @@
#define ULPI_DATA(n) ((n) & 255)
#define ULPI_DATA_READ(n) (((n) >> 8) & 255)
+#define ASYNC_INTR_CTRL (1 << 29) /* Enable async interrupt */
+#define ULPI_STP_CTRL (1 << 30) /* Block communication with PHY */
+
/* OTG definitions */
#define OTGSC_INTSTS_MASK (0x7f << 16)
#define OTGSC_ID (1 << 8)