Add support for setting the Programmable Gain Amplifiers by adjust the
scale value.
Signed-off-by: Marcus Folkesson <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
---
Notes:
Based on
Link: https://lore.kernel.org/all/[email protected]/
But with tmp0, tmp1 and tmp2 removed as those are not needed.
Link: https://lore.kernel.org/all/[email protected]/
drivers/iio/adc/mcp3911.c | 104 +++++++++++++++++++++++++++++---------
1 file changed, 80 insertions(+), 24 deletions(-)
diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
index 0151258b456c..0d768006eabb 100644
--- a/drivers/iio/adc/mcp3911.c
+++ b/drivers/iio/adc/mcp3911.c
@@ -29,6 +29,8 @@
#define MCP3911_REG_MOD 0x06
#define MCP3911_REG_PHASE 0x07
#define MCP3911_REG_GAIN 0x09
+#define MCP3911_GAIN_MASK(ch) (GENMASK(2, 0) << 3 * ch)
+#define MCP3911_GAIN_VAL(ch, val) ((val << 3 * ch) & MCP3911_GAIN_MASK(ch))
#define MCP3911_REG_STATUSCOM 0x0a
#define MCP3911_STATUSCOM_DRHIZ BIT(12)
@@ -59,8 +61,10 @@
#define MCP3911_REG_WRITE(reg, id) ((((reg) << 1) | ((id) << 5) | (0 << 0)) & 0xff)
#define MCP3911_NUM_CHANNELS 2
+#define MCP3911_NUM_SCALES 6
static const int mcp3911_osr_table[] = { 32, 64, 128, 256, 512, 1024, 2048, 4096 };
+static u32 mcp3911_scale_table[MCP3911_NUM_SCALES][2];
struct mcp3911 {
struct spi_device *spi;
@@ -69,6 +73,7 @@ struct mcp3911 {
struct clk *clki;
u32 dev_addr;
struct iio_trigger *trig;
+ u32 gain[MCP3911_NUM_CHANNELS];
struct {
u32 channels[MCP3911_NUM_CHANNELS];
s64 ts __aligned(8);
@@ -145,6 +150,11 @@ static int mcp3911_read_avail(struct iio_dev *indio_dev,
*vals = mcp3911_osr_table;
*length = ARRAY_SIZE(mcp3911_osr_table);
return IIO_AVAIL_LIST;
+ case IIO_CHAN_INFO_SCALE:
+ *type = IIO_VAL_INT_PLUS_NANO;
+ *vals = (int *)mcp3911_scale_table;
+ *length = ARRAY_SIZE(mcp3911_scale_table) * 2;
+ return IIO_AVAIL_LIST;
default:
return -EINVAL;
}
@@ -189,29 +199,9 @@ static int mcp3911_read_raw(struct iio_dev *indio_dev,
break;
case IIO_CHAN_INFO_SCALE:
- if (adc->vref) {
- ret = regulator_get_voltage(adc->vref);
- if (ret < 0) {
- dev_err(indio_dev->dev.parent,
- "failed to get vref voltage: %d\n",
- ret);
- goto out;
- }
-
- *val = ret / 1000;
- } else {
- *val = MCP3911_INT_VREF_MV;
- }
-
- /*
- * For 24bit Conversion
- * Raw = ((Voltage)/(Vref) * 2^23 * Gain * 1.5
- * Voltage = Raw * (Vref)/(2^23 * Gain * 1.5)
- */
-
- /* val2 = (2^23 * 1.5) */
- *val2 = 12582912;
- ret = IIO_VAL_FRACTIONAL;
+ *val = mcp3911_scale_table[ilog2(adc->gain[channel->channel])][0];
+ *val2 = mcp3911_scale_table[ilog2(adc->gain[channel->channel])][1];
+ ret = IIO_VAL_INT_PLUS_NANO;
break;
}
@@ -229,6 +219,18 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
mutex_lock(&adc->lock);
switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ for (int i = 0; i < MCP3911_NUM_SCALES; i++) {
+ if (val == mcp3911_scale_table[i][0] &&
+ val2 == mcp3911_scale_table[i][1]) {
+
+ adc->gain[channel->channel] = BIT(i);
+ ret = mcp3911_update(adc, MCP3911_REG_GAIN,
+ MCP3911_GAIN_MASK(channel->channel),
+ MCP3911_GAIN_VAL(channel->channel, i), 1);
+ }
+ }
+ break;
case IIO_CHAN_INFO_OFFSET:
if (val2 != 0) {
ret = -EINVAL;
@@ -264,6 +266,44 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
return ret;
}
+static int mcp3911_calc_scale_table(struct mcp3911 *adc)
+{
+ u32 ref = MCP3911_INT_VREF_MV;
+ u32 div;
+ int ret;
+ u64 tmp;
+
+ if (adc->vref) {
+ ret = regulator_get_voltage(adc->vref);
+ if (ret < 0) {
+ dev_err(&adc->spi->dev,
+ "failed to get vref voltage: %d\n",
+ ret);
+ return ret;
+ }
+
+ ref = ret / 1000;
+ }
+
+ /*
+ * For 24-bit Conversion
+ * Raw = ((Voltage)/(Vref) * 2^23 * Gain * 1.5
+ * Voltage = Raw * (Vref)/(2^23 * Gain * 1.5)
+ *
+ * ref = Reference voltage
+ * div = (2^23 * 1.5 * gain) = 12582912 * gain
+ */
+ for (int i = 0; i < MCP3911_NUM_SCALES; i++) {
+ div = 12582912 * BIT(i);
+ tmp = div_s64((s64)ref * 1000000000LL, div);
+
+ mcp3911_scale_table[i][0] = 0;
+ mcp3911_scale_table[i][1] = tmp;
+ }
+
+ return 0;
+}
+
#define MCP3911_CHAN(idx) { \
.type = IIO_VOLTAGE, \
.indexed = 1, \
@@ -273,8 +313,10 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_OFFSET) | \
BIT(IIO_CHAN_INFO_SCALE), \
- .info_mask_shared_by_type_available = \
+ .info_mask_shared_by_type_available = \
BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
+ .info_mask_separate_available = \
+ BIT(IIO_CHAN_INFO_SCALE), \
.scan_type = { \
.sign = 's', \
.realbits = 24, \
@@ -483,6 +525,20 @@ static int mcp3911_probe(struct spi_device *spi)
if (ret)
return ret;
+ ret = mcp3911_calc_scale_table(adc);
+ if (ret)
+ return ret;
+
+ /* Set gain to 1 for all channels */
+ for (int i = 0; i < MCP3911_NUM_CHANNELS; i++) {
+ adc->gain[i] = 1;
+ ret = mcp3911_update(adc, MCP3911_REG_GAIN,
+ MCP3911_GAIN_MASK(i),
+ MCP3911_GAIN_VAL(i, 0), 1);
+ if (ret)
+ return ret;
+ }
+
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->info = &mcp3911_info;
--
2.37.1
On 22/09/2022 21:46, Marcus Folkesson wrote:
> Add support for setting the Programmable Gain Amplifiers by adjust the
> scale value.
>
> Signed-off-by: Marcus Folkesson <[email protected]>
> Reviewed-by: Andy Shevchenko <[email protected]>
> ---
>
> Notes:
> Based on
> Link: https://lore.kernel.org/all/[email protected]/
>
> But with tmp0, tmp1 and tmp2 removed as those are not needed.
> Link: https://lore.kernel.org/all/[email protected]/
>
> drivers/iio/adc/mcp3911.c | 104 +++++++++++++++++++++++++++++---------
No need to cc-us. Use scripts/get_maintainers.pl.
Best regards,
Krzysztof
On Thu, Sep 22, 2022 at 11:00 PM Krzysztof Kozlowski
<[email protected]> wrote:
> On 22/09/2022 21:46, Marcus Folkesson wrote:
...
> No need to cc-us. Use scripts/get_maintainers.pl.
While I understand your point it's much easier to Cc all related
people for all patches in the series, given the fact that many (code)
maintainers ask for that (Cc'ing them all patches). So I prefer to be
on the contributor side for the sake of ease of contribution.
--
With Best Regards,
Andy Shevchenko
On 22/09/2022 23:07, Andy Shevchenko wrote:
> On Thu, Sep 22, 2022 at 11:00 PM Krzysztof Kozlowski
> <[email protected]> wrote:
>> On 22/09/2022 21:46, Marcus Folkesson wrote:
>
> ...
>
>> No need to cc-us. Use scripts/get_maintainers.pl.
>
> While I understand your point it's much easier to Cc all related
> people for all patches in the series, given the fact that many (code)
> maintainers ask for that (Cc'ing them all patches). So I prefer to be
> on the contributor side for the sake of ease of contribution.
Then please explain me how I am related to this patchset (it's one
patch, BTW, not a patchset)...
Best regards,
Krzysztof
On Fri, Sep 23, 2022 at 12:24 PM Krzysztof Kozlowski
<[email protected]> wrote:
>
> On 22/09/2022 23:07, Andy Shevchenko wrote:
> > On Thu, Sep 22, 2022 at 11:00 PM Krzysztof Kozlowski
> > <[email protected]> wrote:
> >> On 22/09/2022 21:46, Marcus Folkesson wrote:
> >
> > ...
> >
> >> No need to cc-us. Use scripts/get_maintainers.pl.
> >
> > While I understand your point it's much easier to Cc all related
> > people for all patches in the series, given the fact that many (code)
> > maintainers ask for that (Cc'ing them all patches). So I prefer to be
> > on the contributor side for the sake of ease of contribution.
>
> Then please explain me how I am related to this patchset (it's one
> patch, BTW, not a patchset)...
That is a good point! I was under the impression that this is a series
with some DT changes.
--
With Best Regards,
Andy Shevchenko
On Fri, 23 Sep 2022 12:29:36 +0300
Andy Shevchenko <[email protected]> wrote:
> On Fri, Sep 23, 2022 at 12:24 PM Krzysztof Kozlowski
> <[email protected]> wrote:
> >
> > On 22/09/2022 23:07, Andy Shevchenko wrote:
> > > On Thu, Sep 22, 2022 at 11:00 PM Krzysztof Kozlowski
> > > <[email protected]> wrote:
> > >> On 22/09/2022 21:46, Marcus Folkesson wrote:
> > >
> > > ...
> > >
> > >> No need to cc-us. Use scripts/get_maintainers.pl.
> > >
> > > While I understand your point it's much easier to Cc all related
> > > people for all patches in the series, given the fact that many (code)
> > > maintainers ask for that (Cc'ing them all patches). So I prefer to be
> > > on the contributor side for the sake of ease of contribution.
> >
> > Then please explain me how I am related to this patchset (it's one
> > patch, BTW, not a patchset)...
>
> That is a good point! I was under the impression that this is a series
> with some DT changes.
It was originally! I picked up the whole series, but this last patch
had some issues that 0-day found so I backed it out. V7 just has
that one patch, so indeed should have had a cleaned up cc list.
Hence the confusion all round!
Jonathan
On Thu, 22 Sep 2022 21:46:39 +0200
Marcus Folkesson <[email protected]> wrote:
> Add support for setting the Programmable Gain Amplifiers by adjust the
> scale value.
>
> Signed-off-by: Marcus Folkesson <[email protected]>
> Reviewed-by: Andy Shevchenko <[email protected]>
Applied to the togreg branch of iio.git and pushed out as testing.
I considered slipping this into my 2nd IIO pull request for this cycle
at the last minute, but wasn't happy skipping normal time being beaten on
by 0-day and time in next, so I didn't. Hence this probably won't make
6.1, but Linus did hint he might do an rc8 in which case I may see
if GregKH will take a 3rd pull late next week.
If not, it'll be 6.2 material.
Thanks,
Jonathan
> ---
>
> Notes:
> Based on
> Link: https://lore.kernel.org/all/[email protected]/
>
> But with tmp0, tmp1 and tmp2 removed as those are not needed.
> Link: https://lore.kernel.org/all/[email protected]/
>
> drivers/iio/adc/mcp3911.c | 104 +++++++++++++++++++++++++++++---------
> 1 file changed, 80 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
> index 0151258b456c..0d768006eabb 100644
> --- a/drivers/iio/adc/mcp3911.c
> +++ b/drivers/iio/adc/mcp3911.c
> @@ -29,6 +29,8 @@
> #define MCP3911_REG_MOD 0x06
> #define MCP3911_REG_PHASE 0x07
> #define MCP3911_REG_GAIN 0x09
> +#define MCP3911_GAIN_MASK(ch) (GENMASK(2, 0) << 3 * ch)
> +#define MCP3911_GAIN_VAL(ch, val) ((val << 3 * ch) & MCP3911_GAIN_MASK(ch))
>
> #define MCP3911_REG_STATUSCOM 0x0a
> #define MCP3911_STATUSCOM_DRHIZ BIT(12)
> @@ -59,8 +61,10 @@
> #define MCP3911_REG_WRITE(reg, id) ((((reg) << 1) | ((id) << 5) | (0 << 0)) & 0xff)
>
> #define MCP3911_NUM_CHANNELS 2
> +#define MCP3911_NUM_SCALES 6
>
> static const int mcp3911_osr_table[] = { 32, 64, 128, 256, 512, 1024, 2048, 4096 };
> +static u32 mcp3911_scale_table[MCP3911_NUM_SCALES][2];
>
> struct mcp3911 {
> struct spi_device *spi;
> @@ -69,6 +73,7 @@ struct mcp3911 {
> struct clk *clki;
> u32 dev_addr;
> struct iio_trigger *trig;
> + u32 gain[MCP3911_NUM_CHANNELS];
> struct {
> u32 channels[MCP3911_NUM_CHANNELS];
> s64 ts __aligned(8);
> @@ -145,6 +150,11 @@ static int mcp3911_read_avail(struct iio_dev *indio_dev,
> *vals = mcp3911_osr_table;
> *length = ARRAY_SIZE(mcp3911_osr_table);
> return IIO_AVAIL_LIST;
> + case IIO_CHAN_INFO_SCALE:
> + *type = IIO_VAL_INT_PLUS_NANO;
> + *vals = (int *)mcp3911_scale_table;
> + *length = ARRAY_SIZE(mcp3911_scale_table) * 2;
> + return IIO_AVAIL_LIST;
> default:
> return -EINVAL;
> }
> @@ -189,29 +199,9 @@ static int mcp3911_read_raw(struct iio_dev *indio_dev,
> break;
>
> case IIO_CHAN_INFO_SCALE:
> - if (adc->vref) {
> - ret = regulator_get_voltage(adc->vref);
> - if (ret < 0) {
> - dev_err(indio_dev->dev.parent,
> - "failed to get vref voltage: %d\n",
> - ret);
> - goto out;
> - }
> -
> - *val = ret / 1000;
> - } else {
> - *val = MCP3911_INT_VREF_MV;
> - }
> -
> - /*
> - * For 24bit Conversion
> - * Raw = ((Voltage)/(Vref) * 2^23 * Gain * 1.5
> - * Voltage = Raw * (Vref)/(2^23 * Gain * 1.5)
> - */
> -
> - /* val2 = (2^23 * 1.5) */
> - *val2 = 12582912;
> - ret = IIO_VAL_FRACTIONAL;
> + *val = mcp3911_scale_table[ilog2(adc->gain[channel->channel])][0];
> + *val2 = mcp3911_scale_table[ilog2(adc->gain[channel->channel])][1];
> + ret = IIO_VAL_INT_PLUS_NANO;
> break;
> }
>
> @@ -229,6 +219,18 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
>
> mutex_lock(&adc->lock);
> switch (mask) {
> + case IIO_CHAN_INFO_SCALE:
> + for (int i = 0; i < MCP3911_NUM_SCALES; i++) {
> + if (val == mcp3911_scale_table[i][0] &&
> + val2 == mcp3911_scale_table[i][1]) {
> +
> + adc->gain[channel->channel] = BIT(i);
> + ret = mcp3911_update(adc, MCP3911_REG_GAIN,
> + MCP3911_GAIN_MASK(channel->channel),
> + MCP3911_GAIN_VAL(channel->channel, i), 1);
> + }
> + }
> + break;
> case IIO_CHAN_INFO_OFFSET:
> if (val2 != 0) {
> ret = -EINVAL;
> @@ -264,6 +266,44 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
> return ret;
> }
>
> +static int mcp3911_calc_scale_table(struct mcp3911 *adc)
> +{
> + u32 ref = MCP3911_INT_VREF_MV;
> + u32 div;
> + int ret;
> + u64 tmp;
> +
> + if (adc->vref) {
> + ret = regulator_get_voltage(adc->vref);
> + if (ret < 0) {
> + dev_err(&adc->spi->dev,
> + "failed to get vref voltage: %d\n",
> + ret);
> + return ret;
> + }
> +
> + ref = ret / 1000;
> + }
> +
> + /*
> + * For 24-bit Conversion
> + * Raw = ((Voltage)/(Vref) * 2^23 * Gain * 1.5
> + * Voltage = Raw * (Vref)/(2^23 * Gain * 1.5)
> + *
> + * ref = Reference voltage
> + * div = (2^23 * 1.5 * gain) = 12582912 * gain
> + */
> + for (int i = 0; i < MCP3911_NUM_SCALES; i++) {
> + div = 12582912 * BIT(i);
> + tmp = div_s64((s64)ref * 1000000000LL, div);
> +
> + mcp3911_scale_table[i][0] = 0;
> + mcp3911_scale_table[i][1] = tmp;
> + }
> +
> + return 0;
> +}
> +
> #define MCP3911_CHAN(idx) { \
> .type = IIO_VOLTAGE, \
> .indexed = 1, \
> @@ -273,8 +313,10 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
> .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
> BIT(IIO_CHAN_INFO_OFFSET) | \
> BIT(IIO_CHAN_INFO_SCALE), \
> - .info_mask_shared_by_type_available = \
> + .info_mask_shared_by_type_available = \
> BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
> + .info_mask_separate_available = \
> + BIT(IIO_CHAN_INFO_SCALE), \
> .scan_type = { \
> .sign = 's', \
> .realbits = 24, \
> @@ -483,6 +525,20 @@ static int mcp3911_probe(struct spi_device *spi)
> if (ret)
> return ret;
>
> + ret = mcp3911_calc_scale_table(adc);
> + if (ret)
> + return ret;
> +
> + /* Set gain to 1 for all channels */
> + for (int i = 0; i < MCP3911_NUM_CHANNELS; i++) {
> + adc->gain[i] = 1;
> + ret = mcp3911_update(adc, MCP3911_REG_GAIN,
> + MCP3911_GAIN_MASK(i),
> + MCP3911_GAIN_VAL(i, 0), 1);
> + if (ret)
> + return ret;
> + }
> +
> indio_dev->name = spi_get_device_id(spi)->name;
> indio_dev->modes = INDIO_DIRECT_MODE;
> indio_dev->info = &mcp3911_info;