4.9-stable review patch. If anyone has any objections, please let me know.
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From: Daniel Lezcano daniel.lezcano@linaro.org
commit 48880b979cdc9ef5a70af020f42b8ba1e51dbd34 upstream.
The step and the base temperature are fixed values, we can simplify the computation by converting the base temperature to milli celsius and use a pre-computed step value. That saves us a lot of mult + div for nothing at runtime.
Take also the opportunity to change the function names to be consistent with the rest of the code.
Signed-off-by: Daniel Lezcano daniel.lezcano@linaro.org Reviewed-by: Leo Yan leo.yan@linaro.org Tested-by: Leo Yan leo.yan@linaro.org Signed-off-by: Eduardo Valentin edubezval@gmail.com Signed-off-by: Kevin Wangtao kevin.wangtao@hisilicon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/thermal/hisi_thermal.c | 41 ++++++++++++++++++++++++++++------------- 1 file changed, 28 insertions(+), 13 deletions(-)
--- a/drivers/thermal/hisi_thermal.c +++ b/drivers/thermal/hisi_thermal.c @@ -35,8 +35,9 @@ #define TEMP0_RST_MSK (0x1C) #define TEMP0_VALUE (0x28)
-#define HISI_TEMP_BASE (-60) +#define HISI_TEMP_BASE (-60000) #define HISI_TEMP_RESET (100000) +#define HISI_TEMP_STEP (784)
#define HISI_MAX_SENSORS 4
@@ -61,19 +62,32 @@ struct hisi_thermal_data { void __iomem *regs; };
-/* in millicelsius */ -static inline int _step_to_temp(int step) +/* + * The temperature computation on the tsensor is as follow: + * Unit: millidegree Celsius + * Step: 255/200 (0.7843) + * Temperature base: -60°C + * + * The register is programmed in temperature steps, every step is 784 + * millidegree and begins at -60 000 m°C + * + * The temperature from the steps: + * + * Temp = TempBase + (steps x 784) + * + * and the steps from the temperature: + * + * steps = (Temp - TempBase) / 784 + * + */ +static inline int hisi_thermal_step_to_temp(int step) { - /* - * Every step equals (1 * 200) / 255 celsius, and finally - * need convert to millicelsius. - */ - return (HISI_TEMP_BASE * 1000 + (step * 200000 / 255)); + return HISI_TEMP_BASE + (step * HISI_TEMP_STEP); }
-static inline long _temp_to_step(long temp) +static inline long hisi_thermal_temp_to_step(long temp) { - return ((temp - HISI_TEMP_BASE * 1000) * 255) / 200000; + return (temp - HISI_TEMP_BASE) / HISI_TEMP_STEP; }
static long hisi_thermal_get_sensor_temp(struct hisi_thermal_data *data, @@ -99,7 +113,7 @@ static long hisi_thermal_get_sensor_temp usleep_range(3000, 5000);
val = readl(data->regs + TEMP0_VALUE); - val = _step_to_temp(val); + val = hisi_thermal_step_to_temp(val);
mutex_unlock(&data->thermal_lock);
@@ -126,10 +140,11 @@ static void hisi_thermal_enable_bind_irq writel((sensor->id << 12), data->regs + TEMP0_CFG);
/* enable for interrupt */ - writel(_temp_to_step(sensor->thres_temp) | 0x0FFFFFF00, + writel(hisi_thermal_temp_to_step(sensor->thres_temp) | 0x0FFFFFF00, data->regs + TEMP0_TH);
- writel(_temp_to_step(HISI_TEMP_RESET), data->regs + TEMP0_RST_TH); + writel(hisi_thermal_temp_to_step(HISI_TEMP_RESET), + data->regs + TEMP0_RST_TH);
/* enable module */ writel(0x1, data->regs + TEMP0_RST_MSK);