[PATCH 2/3] platform/x86: GPD pocket fan: Use a min-speed of 2 while charging

From: Hans de Goede
Date: Fri Jan 19 2018 - 15:47:35 EST


Newer versions of the GPD pocket BIOS set the fan-speed to 2 when a
charger gets plugged in while the device is off. Mirror this in our
fan driver and use a minimum speed of 2 while charging,

Cc: James <kernel@xxxxxxxxxxxxx>
Suggested-by: James <kernel@xxxxxxxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
drivers/platform/x86/gpd-pocket-fan.c | 28 ++++++++++++++++++++++++----
1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/drivers/platform/x86/gpd-pocket-fan.c b/drivers/platform/x86/gpd-pocket-fan.c
index 1fdf2205730d..f7b4980c0aa6 100644
--- a/drivers/platform/x86/gpd-pocket-fan.c
+++ b/drivers/platform/x86/gpd-pocket-fan.c
@@ -7,6 +7,7 @@

#include <linux/acpi.h>
#include <linux/gpio/consumer.h>
+#include <linux/power_supply.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
@@ -25,6 +26,11 @@ module_param(hysteresis, int, 0444);
MODULE_PARM_DESC(hysteresis,
"Hysteresis in milli-celcius before lowering the fan speed");

+static int speed_on_ac = 2;
+module_param(speed_on_ac, int, 0444);
+MODULE_PARM_DESC(speed_on_ac,
+ "minimum fan speed to allow when system is powered by AC");
+
struct gpd_pocket_fan_data {
struct device *dev;
struct thermal_zone_device *dts0;
@@ -46,11 +52,19 @@ static void gpd_pocket_fan_set_speed(struct gpd_pocket_fan_data *fan, int speed)
fan->last_speed = speed;
}

+static int gpd_pocket_fan_min_speed(void)
+{
+ if (power_supply_is_system_supplied())
+ return speed_on_ac;
+ else
+ return 0;
+}
+
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;
+ int t0, t1, temp, speed, min_speed, i;

if (thermal_zone_get_temp(fan->dts0, &t0) ||
thermal_zone_get_temp(fan->dts1, &t1)) {
@@ -62,9 +76,10 @@ static void gpd_pocket_fan_worker(struct work_struct *work)
temp = max(t0, t1);

speed = fan->last_speed;
+ min_speed = gpd_pocket_fan_min_speed();

/* Determine minimum speed */
- for (i = 0; i < ARRAY_SIZE(temp_limits); i++) {
+ for (i = min_speed; i < ARRAY_SIZE(temp_limits); i++) {
if (temp < temp_limits[i])
break;
}
@@ -72,7 +87,7 @@ static void gpd_pocket_fan_worker(struct work_struct *work)
speed = i;

/* Use hysteresis before lowering speed again */
- for (i = 0; i < ARRAY_SIZE(temp_limits); i++) {
+ for (i = min_speed; i < ARRAY_SIZE(temp_limits); i++) {
if (temp <= (temp_limits[i] - hysteresis))
break;
}
@@ -113,6 +128,11 @@ static int gpd_pocket_fan_probe(struct platform_device *pdev)
hysteresis);
return -EINVAL;
}
+ if (speed_on_ac < 0 || speed_on_ac > MAX_SPEED) {
+ dev_err(&pdev->dev, "Invalid speed_on_ac %d (must be between 0 and 3)\n",
+ speed_on_ac);
+ return -EINVAL;
+ }

fan = devm_kzalloc(&pdev->dev, sizeof(*fan), GFP_KERNEL);
if (!fan)
@@ -157,7 +177,7 @@ 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);
+ gpd_pocket_fan_set_speed(fan, gpd_pocket_fan_min_speed());
return 0;
}

--
2.14.3