4 files changed, 212 insertions, 0 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 825acf165c2d..bc4d77695918 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5947,6 +5947,12 @@ L:	linux-input@vger.kernel.org
 S:      Maintained
 F:      drivers/input/touchscreen/goodix.c
 
+GPD POCKET FAN DRIVER
+M:      Hans de Goede <hdegoede@redhat.com>
+L:      platform-driver-x86@vger.kernel.org
+S:      Maintained
+F:      drivers/platform/x86/gpd-pocket-fan.c
+
 GPIO ACPI SUPPORT
 M:      Mika Westerberg <mika.westerberg@linux.intel.com>
 M:      Andy Shevchenko <andriy.shevchenko@linux.intel.com>
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 88bf2f46b7a4..8a07df54a67e 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -258,6 +258,18 @@ config AMILO_RFKILL
           This is a driver for enabling wifi on some Fujitsu-Siemens Amilo
           laptops.
 
+config GPD_POCKET_FAN
+        tristate "GPD Pocket Fan Controller support"
+        depends on ACPI
+        depends on THERMAL
+        ---help---
+          Driver for the GPD Pocket vendor specific FAN02501 ACPI device
+          which controls the fan speed on the GPD Pocket.
+
+          Without this driver the fan on the Pocket will stay off independent
+          of the CPU temperature. Say Y or M if the kernel may be used on a
+          GPD pocket.
+
 config TC1100_WMI
         tristate "HP Compaq TC1100 Tablet WMI Extras"
         depends on !X86_64
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 4f92dbf30900..57f37e55786a 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_HP_ACCEL)		+= hp_accel.o
 obj-$(CONFIG_HP_WIRELESS)       += hp-wireless.o
 obj-$(CONFIG_HP_WMI)            += hp-wmi.o
 obj-$(CONFIG_AMILO_RFKILL)      += amilo-rfkill.o
+obj-$(CONFIG_GPD_POCKET_FAN)    += gpd-pocket-fan.o
 obj-$(CONFIG_TC1100_WMI)        += tc1100-wmi.o
 obj-$(CONFIG_SONY_LAPTOP)       += sony-laptop.o
 obj-$(CONFIG_IDEAPAD_LAPTOP)    += ideapad-laptop.o
diff --git a/drivers/platform/x86/gpd-pocket-fan.c b/drivers/platform/x86/gpd-pocket-fan.c
new file mode 100644
index 000000000000..c6f4d89b1437
--- /dev/null
+++ b/drivers/platform/x86/gpd-pocket-fan.c
@@ -0,0 +1,193 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * GPD Pocket fan controller driver
+ *
+ * Copyright (C) 2017 Hans de Goede <hdegoede@redhat.com>
+ */
+
+#include <linux/acpi.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/platform_device.h>
+#include <linux/thermal.h>
+#include <linux/workqueue.h>
+
+static int temp_limits[3] = { 55000, 60000, 65000 };
+module_param_array(temp_limits, int, NULL, 0444);
+MODULE_PARM_DESC(temp_limits,
+                 "Milli-celcius values above which the fan speed increases");
+
+static int hysteresis = 3000;
+module_param(hysteresis, int, 0444);
+MODULE_PARM_DESC(hysteresis,
+                 "Hysteresis in milli-celcius before lowering the fan speed");
+
+struct gpd_pocket_fan_data {
+        struct device *dev;
+        struct thermal_zone_device *dts0;
+        struct thermal_zone_device *dts1;
+        struct gpio_desc *gpio0;
+        struct gpio_desc *gpio1;
+        struct delayed_work work;
+        int last_speed;
+};
+
+static void gpd_pocket_fan_set_speed(struct gpd_pocket_fan_data *fan, int speed)
+{
+        if (speed == fan->last_speed)
+                return;
+
+        gpiod_direction_output(fan->gpio0, !!(speed & 1));
+        gpiod_direction_output(fan->gpio1, !!(speed & 2));
+
+        fan->last_speed = speed;
+}
+
+static void gpd_pocket_fan_worker(struct work_struct *work)
+{
+        struct gpd_pocket_fan_data *fan =
+                container_of(work, struct gpd_pocket_fan_data, work.work);
+        int t0, t1, temp, speed, i;
+
+        if (thermal_zone_get_temp(fan->dts0, &t0) ||
+            thermal_zone_get_temp(fan->dts1, &t1)) {
+                dev_warn(fan->dev, "Error getting temperature\n");
+                queue_delayed_work(system_wq, &fan->work,
+                                   msecs_to_jiffies(1000));
+                return;
+        }
+
+        temp = max(t0, t1);
+
+        speed = fan->last_speed;
+
+        /* Determine minimum speed */
+        for (i = 0; i < ARRAY_SIZE(temp_limits); i++) {
+                if (temp < temp_limits[i])
+                        break;
+        }
+        if (speed < i)
+                speed = i;
+
+        /* Use hysteresis before lowering speed again */
+        for (i = 0; i < ARRAY_SIZE(temp_limits); i++) {
+                if (temp <= (temp_limits[i] - hysteresis))
+                        break;
+        }
+        if (speed > i)
+                speed = i;
+
+        if (fan->last_speed <= 0 && speed)
+                speed = 3; /* kick start motor */
+
+        gpd_pocket_fan_set_speed(fan, speed);
+
+        /* When mostly idle (low temp/speed), slow down the poll interval. */
+        queue_delayed_work(system_wq, &fan->work,
+                           msecs_to_jiffies(4000 / (speed + 1)));
+}
+
+static void gpd_pocket_fan_force_update(struct gpd_pocket_fan_data *fan)
+{
+        fan->last_speed = -1;
+        mod_delayed_work(system_wq, &fan->work, 0);
+}
+
+static int gpd_pocket_fan_probe(struct platform_device *pdev)
+{
+        struct gpd_pocket_fan_data *fan;
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(temp_limits); i++) {
+                if (temp_limits[i] < 40000 || temp_limits[i] > 70000) {
+                        dev_err(&pdev->dev, "Invalid temp-limit %d (must be between 40000 and 70000)\n",
+                                temp_limits[i]);
+                        return -EINVAL;
+                }
+        }
+        if (hysteresis < 1000 || hysteresis > 10000) {
+                dev_err(&pdev->dev, "Invalid hysteresis %d (must be between 1000 and 10000)\n",
+                        hysteresis);
+                return -EINVAL;
+        }
+
+        fan = devm_kzalloc(&pdev->dev, sizeof(*fan), GFP_KERNEL);
+        if (!fan)
+                return -ENOMEM;
+
+        fan->dev = &pdev->dev;
+        INIT_DELAYED_WORK(&fan->work, gpd_pocket_fan_worker);
+
+        /* Note this returns a "weak" reference which we don't need to free */
+        fan->dts0 = thermal_zone_get_zone_by_name("soc_dts0");
+        if (IS_ERR(fan->dts0))
+                return -EPROBE_DEFER;
+
+        fan->dts1 = thermal_zone_get_zone_by_name("soc_dts1");
+        if (IS_ERR(fan->dts1))
+                return -EPROBE_DEFER;
+
+        fan->gpio0 = devm_gpiod_get_index(fan->dev, NULL, 0, GPIOD_ASIS);
+        if (IS_ERR(fan->gpio0))
+                return PTR_ERR(fan->gpio0);
+
+        fan->gpio1 = devm_gpiod_get_index(fan->dev, NULL, 1, GPIOD_ASIS);
+        if (IS_ERR(fan->gpio1))
+                return PTR_ERR(fan->gpio1);
+
+        gpd_pocket_fan_force_update(fan);
+
+        platform_set_drvdata(pdev, fan);
+        return 0;
+}
+
+static int gpd_pocket_fan_remove(struct platform_device *pdev)
+{
+        struct gpd_pocket_fan_data *fan = platform_get_drvdata(pdev);
+
+        cancel_delayed_work_sync(&fan->work);
+        return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int gpd_pocket_fan_suspend(struct device *dev)
+{
+        struct gpd_pocket_fan_data *fan = dev_get_drvdata(dev);
+
+        gpd_pocket_fan_set_speed(fan, 0);
+        return 0;
+}
+
+static int gpd_pocket_fan_resume(struct device *dev)
+{
+        struct gpd_pocket_fan_data *fan = dev_get_drvdata(dev);
+
+        gpd_pocket_fan_force_update(fan);
+        return 0;
+}
+#endif
+static SIMPLE_DEV_PM_OPS(gpd_pocket_fan_pm_ops,
+                         gpd_pocket_fan_suspend,
+                         gpd_pocket_fan_resume);
+
+static struct acpi_device_id gpd_pocket_fan_acpi_match[] = {
+        { "FAN02501" },
+        {},
+};
+MODULE_DEVICE_TABLE(acpi, gpd_pocket_fan_acpi_match);
+
+static struct platform_driver gpd_pocket_fan_driver = {
+        .probe  = gpd_pocket_fan_probe,
+        .remove = gpd_pocket_fan_remove,
+        .driver = {
+                .name                   = "gpd_pocket_fan",
+                .acpi_match_table       = gpd_pocket_fan_acpi_match,
+                .pm                     = &gpd_pocket_fan_pm_ops,
+         },
+};
+
+module_platform_driver(gpd_pocket_fan_driver);
+MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com");
+MODULE_DESCRIPTION("GPD pocket fan driver");
+MODULE_LICENSE("GPL");