summaryrefslogtreecommitdiffstats
path: root/drivers/pwm/pwm-lpss-platform.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--drivers/pwm/pwm-lpss-platform.c93
1 files changed, 93 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-lpss-platform.c b/drivers/pwm/pwm-lpss-platform.c
new file mode 100644
index 000000000..c48c6f2b2
--- /dev/null
+++ b/drivers/pwm/pwm-lpss-platform.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel Low Power Subsystem PWM controller driver
+ *
+ * Copyright (C) 2014, Intel Corporation
+ *
+ * Derived from the original pwm-lpss.c
+ */
+
+#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/property.h>
+
+#include "pwm-lpss.h"
+
+
+static int pwm_lpss_probe_platform(struct platform_device *pdev)
+{
+ const struct pwm_lpss_boardinfo *info;
+ struct pwm_lpss_chip *lpwm;
+ void __iomem *base;
+
+ info = device_get_match_data(&pdev->dev);
+ if (!info)
+ return -ENODEV;
+
+ base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ lpwm = pwm_lpss_probe(&pdev->dev, base, info);
+ if (IS_ERR(lpwm))
+ return PTR_ERR(lpwm);
+
+ platform_set_drvdata(pdev, lpwm);
+
+ /*
+ * On Cherry Trail devices the GFX0._PS0 AML checks if the controller
+ * is on and if it is not on it turns it on and restores what it
+ * believes is the correct state to the PWM controller.
+ * Because of this we must disallow direct-complete, which keeps the
+ * controller (runtime)suspended on resume, to avoid 2 issues:
+ * 1. The controller getting turned on without the linux-pm code
+ * knowing about this. On devices where the controller is unused
+ * this causes it to stay on during the next suspend causing high
+ * battery drain (because S0i3 is not reached)
+ * 2. The state restoring code unexpectedly messing with the controller
+ *
+ * Leaving the controller runtime-suspended (skipping runtime-resume +
+ * normal-suspend) during suspend is fine.
+ */
+ if (info->other_devices_aml_touches_pwm_regs)
+ dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE|
+ DPM_FLAG_SMART_SUSPEND);
+
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+
+ return 0;
+}
+
+static int pwm_lpss_remove_platform(struct platform_device *pdev)
+{
+ pm_runtime_disable(&pdev->dev);
+ return 0;
+}
+
+static const struct acpi_device_id pwm_lpss_acpi_match[] = {
+ { "80860F09", (unsigned long)&pwm_lpss_byt_info },
+ { "80862288", (unsigned long)&pwm_lpss_bsw_info },
+ { "80862289", (unsigned long)&pwm_lpss_bsw_info },
+ { "80865AC8", (unsigned long)&pwm_lpss_bxt_info },
+ { },
+};
+MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match);
+
+static struct platform_driver pwm_lpss_driver_platform = {
+ .driver = {
+ .name = "pwm-lpss",
+ .acpi_match_table = pwm_lpss_acpi_match,
+ },
+ .probe = pwm_lpss_probe_platform,
+ .remove = pwm_lpss_remove_platform,
+};
+module_platform_driver(pwm_lpss_driver_platform);
+
+MODULE_DESCRIPTION("PWM platform driver for Intel LPSS");
+MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS(PWM_LPSS);
+MODULE_ALIAS("platform:pwm-lpss");