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thermal: rockchip: optimize the conversion table

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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 <wxt@rock-chips.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
This commit is contained in:
Caesar Wang 2016-12-12 19:05:34 +08:00 committed by Eduardo Valentin
parent d3530497f5
commit cadf29dc2a
1 changed files with 24 additions and 1 deletions
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25
drivers/thermal/rockchip_thermal.c
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@ -317,6 +317,7 @@ static const struct tsadc_table rk3288_code_table[] = {
{3452, 115000},
{3437, 120000},
{3421, 125000},
{0, 125000},
};
static const struct tsadc_table rk3368_code_table[] = {
@ -401,10 +402,12 @@ 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;
high = table->length - 1;
high = (table->length - 1) - 1; /* ignore the last check for table */
mid = (high + low) / 2;
/* Return mask code data when the temp is over table range */
@ -421,6 +424,26 @@ 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 + 1].code - table->id[mid].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: unknown table mode: %d\n", __func__, table->mode);
return error;
}
exit:
pr_err("%s: invalid temperature, temp=%d error=%d\n",
__func__, temp, error);