From: Andrey Smirnov Date: Tue, 10 Dec 2019 16:41:51 +0000 (-0800) Subject: thermal: qoriq: Do not report invalid temperature reading X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=36564d7e53f9efd14ab5692cd9475a75e8000c98;p=linux.git thermal: qoriq: Do not report invalid temperature reading Before returning measured temperature data to upper layer we need to make sure that the reading was marked as "valid" to avoid reporting bogus data. Signed-off-by: Andrey Smirnov Reviewed-by: Daniel Lezcano Tested-by: Lucas Stach Cc: Chris Healy Cc: Lucas Stach Cc: Eduardo Valentin Cc: Daniel Lezcano Cc: Angus Ainslie (Purism) Cc: linux-imx@nxp.com Cc: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20191210164153.10463-11-andrew.smirnov@gmail.com --- diff --git a/drivers/thermal/qoriq_thermal.c b/drivers/thermal/qoriq_thermal.c index 9a455948ddf05..1730dbe5eeb6a 100644 --- a/drivers/thermal/qoriq_thermal.c +++ b/drivers/thermal/qoriq_thermal.c @@ -49,6 +49,7 @@ #define REGS_TRITSR(n) (0x100 + 16 * (n)) /* Immediate Temperature * Site Register */ +#define TRITSR_V BIT(31) #define REGS_TTRnCR(n) (0xf10 + 4 * (n)) /* Temperature Range n * Control Register */ @@ -81,8 +82,24 @@ static int tmu_get_temp(void *p, int *temp) struct qoriq_sensor *qsensor = p; struct qoriq_tmu_data *qdata = qoriq_sensor_to_data(qsensor); u32 val; + /* + * REGS_TRITSR(id) has the following layout: + * + * 31 ... 7 6 5 4 3 2 1 0 + * V TEMP + * + * Where V bit signifies if the measurement is ready and is + * within sensor range. TEMP is an 8 bit value representing + * temperature in C. + */ + if (regmap_read_poll_timeout(qdata->regmap, + REGS_TRITSR(qsensor->id), + val, + val & TRITSR_V, + USEC_PER_MSEC, + 10 * USEC_PER_MSEC)) + return -ENODATA; - regmap_read(qdata->regmap, REGS_TRITSR(qsensor->id), &val); *temp = (val & 0xff) * 1000; return 0;