* [RFC] iio: mxs-lradc: compute temperature from channel 8 and 9
@ 2013-07-01 17:16 Alexandre Belloni
2013-07-12 9:25 ` Alexandre Belloni
0 siblings, 1 reply; 3+ messages in thread
From: Alexandre Belloni @ 2013-07-01 17:16 UTC (permalink / raw)
To: Jonathan Cameron
Cc: Maxime Ripard, jimwall, brian, Greg Kroah-Hartman, linux-iio,
devel, linux-kernel, Lars-Peter Clausen, Alexandre Belloni
The mxs LRADC is able to read an internal die temperature sensor. The
temperature has to be calculated from the value read on channel 8 and channel 9.
To be able to expose the result to hwmon, implement iio channel 8 as
(channel 9 - channel 8). Then, implement IIO_CHAN_INFO_SCALE and
IIO_CHAN_INFO_OFFSET so that it can be processed by hwmon through the in kernel
provider/consumer mechanism.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
drivers/staging/iio/adc/mxs-lradc.c | 99 ++++++++++++++++++++++++++++++-------
1 file changed, 82 insertions(+), 17 deletions(-)
diff --git a/drivers/staging/iio/adc/mxs-lradc.c b/drivers/staging/iio/adc/mxs-lradc.c
index 163c638..df1d81e 100644
--- a/drivers/staging/iio/adc/mxs-lradc.c
+++ b/drivers/staging/iio/adc/mxs-lradc.c
@@ -225,26 +225,14 @@ struct mxs_lradc {
#define LRADC_CTRL4_LRADCSELECT_MASK(n) (0xf << ((n) * 4))
#define LRADC_CTRL4_LRADCSELECT_OFFSET(n) ((n) * 4)
-/*
- * Raw I/O operations
- */
-static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
- const struct iio_chan_spec *chan,
- int *val, int *val2, long m)
+static int mxs_lradc_read_single(struct iio_dev *iio_dev, int chan, int *val)
{
struct mxs_lradc *lradc = iio_priv(iio_dev);
int ret;
unsigned long mask;
- if (m != IIO_CHAN_INFO_RAW)
- return -EINVAL;
-
- /* Check for invalid channel */
- if (chan->channel > LRADC_MAX_TOTAL_CHANS)
- return -EINVAL;
-
/* Validate the channel if it doesn't intersect with reserved chans. */
- bitmap_set(&mask, chan->channel, 1);
+ bitmap_set(&mask, chan, 1);
ret = iio_validate_scan_mask_onehot(iio_dev, &mask);
if (ret)
return -EINVAL;
@@ -273,7 +261,7 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
/* Clean the slot's previous content, then set new one. */
writel(LRADC_CTRL4_LRADCSELECT_MASK(0),
lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR);
- writel(chan->channel, lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET);
+ writel(chan, lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET);
writel(0, lradc->base + LRADC_CH(0));
@@ -302,6 +290,74 @@ err:
return ret;
}
+static int mxs_lradc_read_temp(struct iio_dev *iio_dev, int *val)
+{
+ int ret, min, max;
+
+ ret = mxs_lradc_read_single(iio_dev, 8, &min);
+ if (ret != IIO_VAL_INT)
+ return ret;
+
+ ret = mxs_lradc_read_single(iio_dev, 9, &max);
+ if (ret != IIO_VAL_INT)
+ return ret;
+
+ *val = max - min;
+
+ return IIO_VAL_INT;
+}
+
+/*
+ * Raw I/O operations
+ */
+static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
+ const struct iio_chan_spec *chan,
+ int *val, int *val2, long m)
+{
+ /* Check for invalid channel */
+ if (chan->channel > LRADC_MAX_TOTAL_CHANS)
+ return -EINVAL;
+
+ switch (m) {
+ case IIO_CHAN_INFO_RAW:
+ if (chan->type == IIO_TEMP)
+ return mxs_lradc_read_temp(iio_dev, val);
+
+ return mxs_lradc_read_single(iio_dev, chan->channel, val);
+
+ case IIO_CHAN_INFO_SCALE:
+ if (chan->type == IIO_TEMP) {
+ /* From the datasheet, we have to multiply by 1.012 and
+ * divide by 4
+ */
+ *val = 0;
+ *val2 = 253000;
+ return IIO_VAL_INT_PLUS_MICRO;
+ }
+
+ return -EINVAL;
+
+ case IIO_CHAN_INFO_OFFSET:
+ if (chan->type == IIO_TEMP) {
+ /* The calculated value from the ADC is in Kelvin, we
+ * want Celsius for hwmon so the offset is
+ * -272.15 * scale
+ */
+ *val = -1075;
+ *val2 = 691699;
+
+ return IIO_VAL_INT_PLUS_MICRO;
+ }
+
+ return -EINVAL;
+
+ default:
+ break;
+ }
+
+ return -EINVAL;
+}
+
static const struct iio_info mxs_lradc_iio_info = {
.driver_module = THIS_MODULE,
.read_raw = mxs_lradc_read_raw,
@@ -836,8 +892,17 @@ static const struct iio_chan_spec mxs_lradc_chan_spec[] = {
MXS_ADC_CHAN(5, IIO_VOLTAGE),
MXS_ADC_CHAN(6, IIO_VOLTAGE),
MXS_ADC_CHAN(7, IIO_VOLTAGE), /* VBATT */
- MXS_ADC_CHAN(8, IIO_TEMP), /* Temp sense 0 */
- MXS_ADC_CHAN(9, IIO_TEMP), /* Temp sense 1 */
+ /* Combined Temperature sensors */
+ {
+ .type = IIO_TEMP,
+ .indexed = 1,
+ .scan_index = 8,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_OFFSET) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .channel = 8,
+ .scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,},
+ },
MXS_ADC_CHAN(10, IIO_VOLTAGE), /* VDDIO */
MXS_ADC_CHAN(11, IIO_VOLTAGE), /* VTH */
MXS_ADC_CHAN(12, IIO_VOLTAGE), /* VDDA */
--
1.8.1.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [RFC] iio: mxs-lradc: compute temperature from channel 8 and 9
2013-07-01 17:16 [RFC] iio: mxs-lradc: compute temperature from channel 8 and 9 Alexandre Belloni
@ 2013-07-12 9:25 ` Alexandre Belloni
2013-07-12 16:37 ` Lars-Peter Clausen
0 siblings, 1 reply; 3+ messages in thread
From: Alexandre Belloni @ 2013-07-12 9:25 UTC (permalink / raw)
To: Alexandre Belloni
Cc: Jonathan Cameron, Maxime Ripard, jimwall, brian,
Greg Kroah-Hartman, linux-iio, devel, linux-kernel,
Lars-Peter Clausen
Hi,
On 01/07/2013 19:16, Alexandre Belloni wrote:
> The mxs LRADC is able to read an internal die temperature sensor. The
> temperature has to be calculated from the value read on channel 8 and channel 9.
> To be able to expose the result to hwmon, implement iio channel 8 as
> (channel 9 - channel 8). Then, implement IIO_CHAN_INFO_SCALE and
> IIO_CHAN_INFO_OFFSET so that it can be processed by hwmon through the in kernel
> provider/consumer mechanism.
>
> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
I didn't get any review on that patch. I know it will already conflict
with what Hector has been working on but would that be the good way to go ?
> ---
> drivers/staging/iio/adc/mxs-lradc.c | 99 ++++++++++++++++++++++++++++++-------
> 1 file changed, 82 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/staging/iio/adc/mxs-lradc.c b/drivers/staging/iio/adc/mxs-lradc.c
> index 163c638..df1d81e 100644
> --- a/drivers/staging/iio/adc/mxs-lradc.c
> +++ b/drivers/staging/iio/adc/mxs-lradc.c
> @@ -225,26 +225,14 @@ struct mxs_lradc {
> #define LRADC_CTRL4_LRADCSELECT_MASK(n) (0xf << ((n) * 4))
> #define LRADC_CTRL4_LRADCSELECT_OFFSET(n) ((n) * 4)
>
> -/*
> - * Raw I/O operations
> - */
> -static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
> - const struct iio_chan_spec *chan,
> - int *val, int *val2, long m)
> +static int mxs_lradc_read_single(struct iio_dev *iio_dev, int chan, int *val)
> {
> struct mxs_lradc *lradc = iio_priv(iio_dev);
> int ret;
> unsigned long mask;
>
> - if (m != IIO_CHAN_INFO_RAW)
> - return -EINVAL;
> -
> - /* Check for invalid channel */
> - if (chan->channel > LRADC_MAX_TOTAL_CHANS)
> - return -EINVAL;
> -
> /* Validate the channel if it doesn't intersect with reserved chans. */
> - bitmap_set(&mask, chan->channel, 1);
> + bitmap_set(&mask, chan, 1);
> ret = iio_validate_scan_mask_onehot(iio_dev, &mask);
> if (ret)
> return -EINVAL;
> @@ -273,7 +261,7 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
> /* Clean the slot's previous content, then set new one. */
> writel(LRADC_CTRL4_LRADCSELECT_MASK(0),
> lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR);
> - writel(chan->channel, lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET);
> + writel(chan, lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET);
>
> writel(0, lradc->base + LRADC_CH(0));
>
> @@ -302,6 +290,74 @@ err:
> return ret;
> }
>
> +static int mxs_lradc_read_temp(struct iio_dev *iio_dev, int *val)
> +{
> + int ret, min, max;
> +
> + ret = mxs_lradc_read_single(iio_dev, 8, &min);
> + if (ret != IIO_VAL_INT)
> + return ret;
> +
> + ret = mxs_lradc_read_single(iio_dev, 9, &max);
> + if (ret != IIO_VAL_INT)
> + return ret;
> +
> + *val = max - min;
> +
> + return IIO_VAL_INT;
> +}
> +
> +/*
> + * Raw I/O operations
> + */
> +static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
> + const struct iio_chan_spec *chan,
> + int *val, int *val2, long m)
> +{
> + /* Check for invalid channel */
> + if (chan->channel > LRADC_MAX_TOTAL_CHANS)
> + return -EINVAL;
> +
> + switch (m) {
> + case IIO_CHAN_INFO_RAW:
> + if (chan->type == IIO_TEMP)
> + return mxs_lradc_read_temp(iio_dev, val);
> +
> + return mxs_lradc_read_single(iio_dev, chan->channel, val);
> +
> + case IIO_CHAN_INFO_SCALE:
> + if (chan->type == IIO_TEMP) {
> + /* From the datasheet, we have to multiply by 1.012 and
> + * divide by 4
> + */
> + *val = 0;
> + *val2 = 253000;
> + return IIO_VAL_INT_PLUS_MICRO;
> + }
> +
> + return -EINVAL;
> +
> + case IIO_CHAN_INFO_OFFSET:
> + if (chan->type == IIO_TEMP) {
> + /* The calculated value from the ADC is in Kelvin, we
> + * want Celsius for hwmon so the offset is
> + * -272.15 * scale
> + */
> + *val = -1075;
> + *val2 = 691699;
> +
> + return IIO_VAL_INT_PLUS_MICRO;
> + }
> +
> + return -EINVAL;
> +
> + default:
> + break;
> + }
> +
> + return -EINVAL;
> +}
> +
> static const struct iio_info mxs_lradc_iio_info = {
> .driver_module = THIS_MODULE,
> .read_raw = mxs_lradc_read_raw,
> @@ -836,8 +892,17 @@ static const struct iio_chan_spec mxs_lradc_chan_spec[] = {
> MXS_ADC_CHAN(5, IIO_VOLTAGE),
> MXS_ADC_CHAN(6, IIO_VOLTAGE),
> MXS_ADC_CHAN(7, IIO_VOLTAGE), /* VBATT */
> - MXS_ADC_CHAN(8, IIO_TEMP), /* Temp sense 0 */
> - MXS_ADC_CHAN(9, IIO_TEMP), /* Temp sense 1 */
> + /* Combined Temperature sensors */
> + {
> + .type = IIO_TEMP,
> + .indexed = 1,
> + .scan_index = 8,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_OFFSET) |
> + BIT(IIO_CHAN_INFO_SCALE),
> + .channel = 8,
> + .scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,},
> + },
> MXS_ADC_CHAN(10, IIO_VOLTAGE), /* VDDIO */
> MXS_ADC_CHAN(11, IIO_VOLTAGE), /* VTH */
> MXS_ADC_CHAN(12, IIO_VOLTAGE), /* VDDA */
--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [RFC] iio: mxs-lradc: compute temperature from channel 8 and 9
2013-07-12 9:25 ` Alexandre Belloni
@ 2013-07-12 16:37 ` Lars-Peter Clausen
0 siblings, 0 replies; 3+ messages in thread
From: Lars-Peter Clausen @ 2013-07-12 16:37 UTC (permalink / raw)
To: Alexandre Belloni
Cc: Jonathan Cameron, Maxime Ripard, jimwall, brian,
Greg Kroah-Hartman, linux-iio, devel, linux-kernel
On 07/12/2013 11:25 AM, Alexandre Belloni wrote:
> Hi,
>
> On 01/07/2013 19:16, Alexandre Belloni wrote:
>> The mxs LRADC is able to read an internal die temperature sensor. The
>> temperature has to be calculated from the value read on channel 8 and channel 9.
>> To be able to expose the result to hwmon, implement iio channel 8 as
>> (channel 9 - channel 8). Then, implement IIO_CHAN_INFO_SCALE and
>> IIO_CHAN_INFO_OFFSET so that it can be processed by hwmon through the in kernel
>> provider/consumer mechanism.
>>
>> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
>
> I didn't get any review on that patch. I know it will already conflict
> with what Hector has been working on but would that be the good way to go ?
Yes, looks good to me. If you don't make any other fixes than resolving the
conflict you can add my
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
>
>
>> ---
>> drivers/staging/iio/adc/mxs-lradc.c | 99 ++++++++++++++++++++++++++++++-------
>> 1 file changed, 82 insertions(+), 17 deletions(-)
>>
>> diff --git a/drivers/staging/iio/adc/mxs-lradc.c b/drivers/staging/iio/adc/mxs-lradc.c
>> index 163c638..df1d81e 100644
>> --- a/drivers/staging/iio/adc/mxs-lradc.c
>> +++ b/drivers/staging/iio/adc/mxs-lradc.c
>> @@ -225,26 +225,14 @@ struct mxs_lradc {
>> #define LRADC_CTRL4_LRADCSELECT_MASK(n) (0xf << ((n) * 4))
>> #define LRADC_CTRL4_LRADCSELECT_OFFSET(n) ((n) * 4)
>>
>> -/*
>> - * Raw I/O operations
>> - */
>> -static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
>> - const struct iio_chan_spec *chan,
>> - int *val, int *val2, long m)
>> +static int mxs_lradc_read_single(struct iio_dev *iio_dev, int chan, int *val)
>> {
>> struct mxs_lradc *lradc = iio_priv(iio_dev);
>> int ret;
>> unsigned long mask;
>>
>> - if (m != IIO_CHAN_INFO_RAW)
>> - return -EINVAL;
>> -
>> - /* Check for invalid channel */
>> - if (chan->channel > LRADC_MAX_TOTAL_CHANS)
>> - return -EINVAL;
>> -
>> /* Validate the channel if it doesn't intersect with reserved chans. */
>> - bitmap_set(&mask, chan->channel, 1);
>> + bitmap_set(&mask, chan, 1);
>> ret = iio_validate_scan_mask_onehot(iio_dev, &mask);
>> if (ret)
>> return -EINVAL;
>> @@ -273,7 +261,7 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
>> /* Clean the slot's previous content, then set new one. */
>> writel(LRADC_CTRL4_LRADCSELECT_MASK(0),
>> lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR);
>> - writel(chan->channel, lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET);
>> + writel(chan, lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET);
>>
>> writel(0, lradc->base + LRADC_CH(0));
>>
>> @@ -302,6 +290,74 @@ err:
>> return ret;
>> }
>>
>> +static int mxs_lradc_read_temp(struct iio_dev *iio_dev, int *val)
>> +{
>> + int ret, min, max;
>> +
>> + ret = mxs_lradc_read_single(iio_dev, 8, &min);
>> + if (ret != IIO_VAL_INT)
>> + return ret;
>> +
>> + ret = mxs_lradc_read_single(iio_dev, 9, &max);
>> + if (ret != IIO_VAL_INT)
>> + return ret;
>> +
>> + *val = max - min;
>> +
>> + return IIO_VAL_INT;
>> +}
>> +
>> +/*
>> + * Raw I/O operations
>> + */
>> +static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
>> + const struct iio_chan_spec *chan,
>> + int *val, int *val2, long m)
>> +{
>> + /* Check for invalid channel */
>> + if (chan->channel > LRADC_MAX_TOTAL_CHANS)
>> + return -EINVAL;
>> +
>> + switch (m) {
>> + case IIO_CHAN_INFO_RAW:
>> + if (chan->type == IIO_TEMP)
>> + return mxs_lradc_read_temp(iio_dev, val);
>> +
>> + return mxs_lradc_read_single(iio_dev, chan->channel, val);
>> +
>> + case IIO_CHAN_INFO_SCALE:
>> + if (chan->type == IIO_TEMP) {
>> + /* From the datasheet, we have to multiply by 1.012 and
>> + * divide by 4
>> + */
>> + *val = 0;
>> + *val2 = 253000;
>> + return IIO_VAL_INT_PLUS_MICRO;
>> + }
>> +
>> + return -EINVAL;
>> +
>> + case IIO_CHAN_INFO_OFFSET:
>> + if (chan->type == IIO_TEMP) {
>> + /* The calculated value from the ADC is in Kelvin, we
>> + * want Celsius for hwmon so the offset is
>> + * -272.15 * scale
>> + */
>> + *val = -1075;
>> + *val2 = 691699;
>> +
>> + return IIO_VAL_INT_PLUS_MICRO;
>> + }
>> +
>> + return -EINVAL;
>> +
>> + default:
>> + break;
>> + }
>> +
>> + return -EINVAL;
>> +}
>> +
>> static const struct iio_info mxs_lradc_iio_info = {
>> .driver_module = THIS_MODULE,
>> .read_raw = mxs_lradc_read_raw,
>> @@ -836,8 +892,17 @@ static const struct iio_chan_spec mxs_lradc_chan_spec[] = {
>> MXS_ADC_CHAN(5, IIO_VOLTAGE),
>> MXS_ADC_CHAN(6, IIO_VOLTAGE),
>> MXS_ADC_CHAN(7, IIO_VOLTAGE), /* VBATT */
>> - MXS_ADC_CHAN(8, IIO_TEMP), /* Temp sense 0 */
>> - MXS_ADC_CHAN(9, IIO_TEMP), /* Temp sense 1 */
>> + /* Combined Temperature sensors */
>> + {
>> + .type = IIO_TEMP,
>> + .indexed = 1,
>> + .scan_index = 8,
>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
>> + BIT(IIO_CHAN_INFO_OFFSET) |
>> + BIT(IIO_CHAN_INFO_SCALE),
>> + .channel = 8,
>> + .scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,},
>> + },
>> MXS_ADC_CHAN(10, IIO_VOLTAGE), /* VDDIO */
>> MXS_ADC_CHAN(11, IIO_VOLTAGE), /* VTH */
>> MXS_ADC_CHAN(12, IIO_VOLTAGE), /* VDDA */
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2013-07-01 17:16 [RFC] iio: mxs-lradc: compute temperature from channel 8 and 9 Alexandre Belloni
2013-07-12 9:25 ` Alexandre Belloni
2013-07-12 16:37 ` Lars-Peter Clausen
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