Subject: [PATCH 2/3] hwmon: Driver for OMAP3 temperature sensor

From: [email-masked] (Pavel Machek)
Date: Sat, 27 Dec 2014 23:35:16 +0100

On Sat 2014-12-27 20:58:25, Pavel Machek wrote:
> On Fri 2014-12-26 13:34:53, Sebastian Reichel wrote:
> > OMAP34xx and OMAP36xx processors contain a register in the syscon area,
> > which can be used to determine the SoCs temperature. This patch provides
> > a DT based driver for the temperature sensor based on an older driver
> > written by Peter De Schrijver for the Nokia N900 and N9.
> > 
> > Signed-off-by: Sebastian Reichel <[email-masked]>
> > ---
> >  drivers/hwmon/Kconfig      |   8 ++
> >  drivers/hwmon/Makefile     |   1 +
> >  drivers/hwmon/omap3-temp.c | 307 +++++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 316 insertions(+)
> >  create mode 100644 drivers/hwmon/omap3-temp.c
> 
> When it hangs, it loops here:
> 
> do {
> regmap_read(data->syscon, SYSCON_TEMP_REG,&temp_sensor_reg);
> if ((temp_sensor_reg & eocz_mask) == level)
>    return true;
> printk("=");
> }
> while (ktime_us_delta(expire, ktime_get()) > 0);

And this fixes the hang, and makes level handling more readable.

Fix the timeout code, now it actually works. Driver still fails after
a while.

Signed-off-by: Pavel Machek <[email-masked]>

diff --git a/drivers/hwmon/omap3-temp.c b/drivers/hwmon/omap3-temp.c
index 8a69604..1b8c768 100644
--- a/drivers/hwmon/omap3-temp.c
+++ b/drivers/hwmon/omap3-temp.c
@@ -130,9 +130,7 @@ static inline bool wait_for_eocz(struct omap3_temp_data *data,
 	ktime_t timeout, expire;
 	u32 temp_sensor_reg, eocz_mask;
 
 	eocz_mask = BIT(data->hwdata->eocz_bit);
-	level &= 1;
-	level *= eocz_mask;
 
 	expire = ktime_add_ns(ktime_get(), max_delay);
 	timeout = ktime_set(0, min_delay);
@@ -140,9 +141,9 @@ static inline bool wait_for_eocz(struct omap3_temp_data *data,
 	schedule_hrtimeout(&timeout, HRTIMER_MODE_REL);
 	do {
 		regmap_read(data->syscon, SYSCON_TEMP_REG, &temp_sensor_reg);
-		if ((temp_sensor_reg & eocz_mask) == level)
+		if (!!(temp_sensor_reg & eocz_mask) == level)
 			return true;
-	} while (ktime_us_delta(expire, ktime_get()) > 0);
+	} while (ktime_after(expire, ktime_get()));
 
 	return false;
 }

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