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

From: Pavel Machek
Date: Sat Dec 27 2014 - 14:41:04 EST


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 <sre@xxxxxxxxxx>

I'd suggest these cleanups... But I don't see why it would fail. (Aha,
and sorry for trailing whitespace, you'll probably need to delete it.)

Signed-off-by: Pavel Machek <pavel@xxxxxx>

diff --git a/drivers/hwmon/omap3-temp.c b/drivers/hwmon/omap3-temp.c
index afe1b5a..8a69604 100644
--- a/drivers/hwmon/omap3-temp.c
+++ b/drivers/hwmon/omap3-temp.c
@@ -35,21 +35,29 @@
/* 32.768Khz clock speed in nano seconds */
#define CLOCK_32K_SPEED_NS 30518

-/* minimum delay for EOCZ rise after SOC rise is
- * 11 cycles of the 32.768Khz clock */
+/*
+ * minimum delay for EOCZ rise after SOC rise is
+ * 11 cycles of the 32.768Khz clock
+ */
#define EOCZ_MIN_RISING_DELAY (11 * CLOCK_32K_SPEED_NS)

-/* From docs, maximum delay for EOCZ rise after SOC rise is
+/*
+ * From docs, maximum delay for EOCZ rise after SOC rise is
* 14 cycles of the 32.768Khz clock. But after some experiments,
- * 24 cycles as maximum is safer. */
+ * 24 cycles as maximum is safer.
+ */
#define EOCZ_MAX_RISING_DELAY (24 * CLOCK_32K_SPEED_NS)

-/* minimum delay for EOCZ falling is
- * 36 cycles of the 32.768Khz clock */
+/*
+ * minimum delay for EOCZ falling is
+ * 36 cycles of the 32.768Khz clock
+ */
#define EOCZ_MIN_FALLING_DELAY (36 * CLOCK_32K_SPEED_NS)

-/* maximum delay for EOCZ falling is
- * 40 cycles of the 32.768Khz clock */
+/*
+ * maximum delay for EOCZ falling is
+ * 40 cycles of the 32.768Khz clock
+ */
#define EOCZ_MAX_FALLING_DELAY (40 * CLOCK_32K_SPEED_NS)

/* temperature register offset in the syscon register area */
@@ -116,8 +124,8 @@ struct omap3_temp_data {
bool valid;
};

-static inline u32 wait_for_eocz(int min_delay, int max_delay, u32 level,
- struct omap3_temp_data *data)
+static inline bool wait_for_eocz(struct omap3_temp_data *data,
+ int min_delay, int max_delay, u32 level)
{
ktime_t timeout, expire;
u32 temp_sensor_reg, eocz_mask;
@@ -133,10 +141,10 @@ static inline u32 wait_for_eocz(int min_delay, int max_delay, u32 level,
do {
regmap_read(data->syscon, SYSCON_TEMP_REG, &temp_sensor_reg);
if ((temp_sensor_reg & eocz_mask) == level)
- break;
+ return true;
} while (ktime_us_delta(expire, ktime_get()) > 0);

- return (temp_sensor_reg & eocz_mask) == level;
+ return false;
}

static int omap3_temp_update(struct omap3_temp_data *data)
@@ -153,16 +161,16 @@ static int omap3_temp_update(struct omap3_temp_data *data)
regmap_update_bits(data->syscon, SYSCON_TEMP_REG,
soc_mask, soc_mask);

- if (!wait_for_eocz(EOCZ_MIN_RISING_DELAY,
- EOCZ_MAX_RISING_DELAY, 1, data)) {
+ if (!wait_for_eocz(data, EOCZ_MIN_RISING_DELAY,
+ EOCZ_MAX_RISING_DELAY, 1)) {
e = -EIO;
goto err;
}

regmap_update_bits(data->syscon, SYSCON_TEMP_REG, soc_mask, 0);

- if (!wait_for_eocz(EOCZ_MIN_FALLING_DELAY,
- EOCZ_MAX_FALLING_DELAY, 0, data)) {
+ if (!wait_for_eocz(data, EOCZ_MIN_FALLING_DELAY,
+ EOCZ_MAX_FALLING_DELAY, 0)) {
e = -EIO;
goto err;
}


--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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