From d36e2fa025387567710df740fd4dce1d5001b226 Mon Sep 17 00:00:00 2001 From: Jean-Francois Dagenais Date: Thu, 18 Apr 2019 12:37:32 -0400 Subject: [PATCH] thermal: generic-adc: make lookup table optional Certain ADC channels, such as the xilinx-ams temperature channels, give milliCelcius already when read with iio_read_channel_processed. Rather than having to provide a 1:1 dummy lookup table, simply allow to bypass the mechanism. Signed-off-by: Jean-Francois Dagenais Signed-off-by: Eduardo Valentin --- drivers/thermal/thermal-generic-adc.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/thermal/thermal-generic-adc.c b/drivers/thermal/thermal-generic-adc.c index e22fc60ad36d..deb244f12de4 100644 --- a/drivers/thermal/thermal-generic-adc.c +++ b/drivers/thermal/thermal-generic-adc.c @@ -29,6 +29,9 @@ static int gadc_thermal_adc_to_temp(struct gadc_thermal_info *gti, int val) int temp, temp_hi, temp_lo, adc_hi, adc_lo; int i; + if (!gti->lookup_table) + return val; + for (i = 0; i < gti->nlookup_table; i++) { if (val >= gti->lookup_table[2 * i + 1]) break; @@ -81,9 +84,9 @@ static int gadc_thermal_read_linear_lookup_table(struct device *dev, ntable = of_property_count_elems_of_size(np, "temperature-lookup-table", sizeof(u32)); - if (ntable < 0) { - dev_err(dev, "Lookup table is not provided\n"); - return ntable; + if (ntable <= 0) { + dev_notice(dev, "no lookup table, assuming DAC channel returns milliCelcius\n"); + return 0; } if (ntable % 2) {