| From 48880b979cdc9ef5a70af020f42b8ba1e51dbd34 Mon Sep 17 00:00:00 2001 |
| From: Daniel Lezcano <daniel.lezcano@linaro.org> |
| Date: Thu, 19 Oct 2017 19:05:46 +0200 |
| Subject: thermal/drivers/hisi: Simplify the temperature/step computation |
| |
| 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); |