In order to support the valid temperature can conver to analog value. The rockchip thermal driver has not supported the all valid temperature to convert the analog value. (e.g.: 61C, 62C, 63C....)
For example: In some cases, we need adjust the trip point. $cd /sys/class/thermal/thermal_zone* $echo 68000 > trip_point_0_temp That will return the max analogic value indicates the invalid before posting this patch. So, this patch will optimize the conversion table to support the other cases. Signed-off-by: Caesar Wang <w...@rock-chips.com> Reviewed-by: Brian Norris <briannor...@chromium.org> --- Changes in v2: - improve the commit as Brian commnets on https://patchwork.kernel.org/patch/9440985 Changes in v1: None drivers/thermal/rockchip_thermal.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/drivers/thermal/rockchip_thermal.c b/drivers/thermal/rockchip_thermal.c index e243e40..0d50df7 100644 --- a/drivers/thermal/rockchip_thermal.c +++ b/drivers/thermal/rockchip_thermal.c @@ -401,6 +401,8 @@ static u32 rk_tsadcv2_temp_to_code(const struct chip_tsadc_table *table, int temp) { int high, low, mid; + unsigned long num; + unsigned int denom; u32 error = table->data_mask; low = 0; @@ -421,6 +423,27 @@ static u32 rk_tsadcv2_temp_to_code(const struct chip_tsadc_table *table, mid = (low + high) / 2; } + /* + * The conversion code granularity provided by the table. Let's + * assume that the relationship between temperature and + * analog value between 2 table entries is linear and interpolate + * to produce less granular result. + */ + num = abs(table->id[mid].code - table->id[mid + 1].code); + num *= temp - table->id[mid].temp; + denom = table->id[mid + 1].temp - table->id[mid].temp; + + switch (table->mode) { + case ADC_DECREMENT: + return table->id[mid].code - (num / denom); + case ADC_INCREMENT: + return table->id[mid].code + (num / denom); + default: + pr_err("%s: invalid conversion table, mode=%d\n", + __func__, table->mode); + return error; + } + exit: pr_err("%s: invalid temperature, temp=%d error=%d\n", __func__, temp, error); -- 2.7.4
