pwm: lpss: Add support for runtime PM
To be able to save some power when PWM is not in use, add support for
runtime PM for this driver. This also allows the platform to transition to
low power S0ix states when the system is idle.
Signed-off-by: Huiquan Zhong <huiquan.zhong@intel.com>
Signed-off-by: Qipeng Zha <qipeng.zha@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
diff --git a/drivers/pwm/pwm-lpss-pci.c b/drivers/pwm/pwm-lpss-pci.c
index c15bc6d..7160e8a 100644
--- a/drivers/pwm/pwm-lpss-pci.c
+++ b/drivers/pwm/pwm-lpss-pci.c
@@ -13,6 +13,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
+#include <linux/pm_runtime.h>
#include "pwm-lpss.h"
@@ -33,6 +34,10 @@
return PTR_ERR(lpwm);
pci_set_drvdata(pdev, lpwm);
+
+ pm_runtime_put(&pdev->dev);
+ pm_runtime_allow(&pdev->dev);
+
return 0;
}
@@ -40,9 +45,33 @@
{
struct pwm_lpss_chip *lpwm = pci_get_drvdata(pdev);
+ pm_runtime_forbid(&pdev->dev);
+ pm_runtime_get_sync(&pdev->dev);
+
pwm_lpss_remove(lpwm);
}
+#ifdef CONFIG_PM
+static int pwm_lpss_runtime_suspend_pci(struct device *dev)
+{
+ /*
+ * The PCI core will handle transition to D3 automatically. We only
+ * need to provide runtime PM hooks for that to happen.
+ */
+ return 0;
+}
+
+static int pwm_lpss_runtime_resume_pci(struct device *dev)
+{
+ return 0;
+}
+#endif
+
+static const struct dev_pm_ops pwm_lpss_pci_pm = {
+ SET_RUNTIME_PM_OPS(pwm_lpss_runtime_suspend_pci,
+ pwm_lpss_runtime_resume_pci, NULL)
+};
+
static const struct pci_device_id pwm_lpss_pci_ids[] = {
{ PCI_VDEVICE(INTEL, 0x0ac8), (unsigned long)&pwm_lpss_bxt_info},
{ PCI_VDEVICE(INTEL, 0x0f08), (unsigned long)&pwm_lpss_byt_info},
@@ -60,6 +89,9 @@
.id_table = pwm_lpss_pci_ids,
.probe = pwm_lpss_probe_pci,
.remove = pwm_lpss_remove_pci,
+ .driver = {
+ .pm = &pwm_lpss_pci_pm,
+ },
};
module_pci_driver(pwm_lpss_driver_pci);
diff --git a/drivers/pwm/pwm-lpss-platform.c b/drivers/pwm/pwm-lpss-platform.c
index a914aac..54433fc 100644
--- a/drivers/pwm/pwm-lpss-platform.c
+++ b/drivers/pwm/pwm-lpss-platform.c
@@ -14,6 +14,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
#include "pwm-lpss.h"
@@ -36,6 +37,10 @@
return PTR_ERR(lpwm);
platform_set_drvdata(pdev, lpwm);
+
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+
return 0;
}
@@ -43,6 +48,7 @@
{
struct pwm_lpss_chip *lpwm = platform_get_drvdata(pdev);
+ pm_runtime_disable(&pdev->dev);
return pwm_lpss_remove(lpwm);
}
diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c
index df03b50..2504410 100644
--- a/drivers/pwm/pwm-lpss.c
+++ b/drivers/pwm/pwm-lpss.c
@@ -16,6 +16,7 @@
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/pm_runtime.h>
#include "pwm-lpss.h"
@@ -105,6 +106,8 @@
duty_ns = 1;
on_time_div = 255 - (255 * duty_ns / period_ns);
+ pm_runtime_get_sync(chip->dev);
+
ctrl = pwm_lpss_read(pwm);
ctrl &= ~(PWM_BASE_UNIT_MASK | PWM_ON_TIME_DIV_MASK);
ctrl |= (u16) base_unit << PWM_BASE_UNIT_SHIFT;
@@ -113,11 +116,14 @@
ctrl |= PWM_SW_UPDATE;
pwm_lpss_write(pwm, ctrl);
+ pm_runtime_put(chip->dev);
+
return 0;
}
static int pwm_lpss_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
+ pm_runtime_get_sync(chip->dev);
pwm_lpss_write(pwm, pwm_lpss_read(pwm) | PWM_ENABLE);
return 0;
}
@@ -125,6 +131,7 @@
static void pwm_lpss_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
pwm_lpss_write(pwm, pwm_lpss_read(pwm) & ~PWM_ENABLE);
+ pm_runtime_put(chip->dev);
}
static const struct pwm_ops pwm_lpss_ops = {