* [PATCH v3 1/9] iio: adc: mcp3911: make use of the sign bit
2022-07-04 17:21 [PATCH v3 0/9] Improve MCP3911 driver Marcus Folkesson
@ 2022-07-04 17:21 ` Marcus Folkesson
2022-07-04 17:21 ` [PATCH v3 2/9] iio: adc: mcp3911: correct "microchip,device-addr" property Marcus Folkesson
` (8 subsequent siblings)
9 siblings, 0 replies; 18+ messages in thread
From: Marcus Folkesson @ 2022-07-04 17:21 UTC (permalink / raw)
To: Marcus Folkesson, Kent Gustavsson, Jonathan Cameron,
Lars-Peter Clausen, Rob Herring, Krzysztof Kozlowski
Cc: linux-iio, devicetree, linux-kernel
The device supports negative values as well.
Fixes: 3a89b289df5d ("iio: adc: add support for mcp3911")
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
---
drivers/iio/adc/mcp3911.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
index 1cb4590fe412..f581cefb6719 100644
--- a/drivers/iio/adc/mcp3911.c
+++ b/drivers/iio/adc/mcp3911.c
@@ -113,6 +113,8 @@ static int mcp3911_read_raw(struct iio_dev *indio_dev,
if (ret)
goto out;
+ *val = sign_extend32(*val, 23);
+
ret = IIO_VAL_INT;
break;
--
2.36.1
^ permalink raw reply related [flat|nested] 18+ messages in thread
* [PATCH v3 2/9] iio: adc: mcp3911: correct "microchip,device-addr" property
2022-07-04 17:21 [PATCH v3 0/9] Improve MCP3911 driver Marcus Folkesson
2022-07-04 17:21 ` [PATCH v3 1/9] iio: adc: mcp3911: make use of the sign bit Marcus Folkesson
@ 2022-07-04 17:21 ` Marcus Folkesson
2022-07-04 17:21 ` [PATCH v3 3/9] iio: adc: mcp3911: use correct formula for AD conversion Marcus Folkesson
` (7 subsequent siblings)
9 siblings, 0 replies; 18+ messages in thread
From: Marcus Folkesson @ 2022-07-04 17:21 UTC (permalink / raw)
To: Marcus Folkesson, Kent Gustavsson, Jonathan Cameron,
Lars-Peter Clausen, Rob Herring, Krzysztof Kozlowski
Cc: linux-iio, devicetree, linux-kernel
Go for the right property name that is documented in the bindings.
Fixes: 3a89b289df5d ("iio: adc: add support for mcp3911")
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
---
drivers/iio/adc/mcp3911.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
index f581cefb6719..f8875076ae80 100644
--- a/drivers/iio/adc/mcp3911.c
+++ b/drivers/iio/adc/mcp3911.c
@@ -210,7 +210,14 @@ static int mcp3911_config(struct mcp3911 *adc)
u32 configreg;
int ret;
- device_property_read_u32(dev, "device-addr", &adc->dev_addr);
+ ret = device_property_read_u32(dev, "microchip,device-addr", &adc->dev_addr);
+
+ /*
+ * Fallback to "device-addr" due to historical mismatch between
+ * dt-bindings and implementation
+ */
+ if (ret)
+ device_property_read_u32(dev, "device-addr", &adc->dev_addr);
if (adc->dev_addr > 3) {
dev_err(&adc->spi->dev,
"invalid device address (%i). Must be in range 0-3.\n",
--
2.36.1
^ permalink raw reply related [flat|nested] 18+ messages in thread
* [PATCH v3 3/9] iio: adc: mcp3911: use correct formula for AD conversion
2022-07-04 17:21 [PATCH v3 0/9] Improve MCP3911 driver Marcus Folkesson
2022-07-04 17:21 ` [PATCH v3 1/9] iio: adc: mcp3911: make use of the sign bit Marcus Folkesson
2022-07-04 17:21 ` [PATCH v3 2/9] iio: adc: mcp3911: correct "microchip,device-addr" property Marcus Folkesson
@ 2022-07-04 17:21 ` Marcus Folkesson
2022-07-16 17:18 ` Jonathan Cameron
2022-07-04 17:21 ` [PATCH v3 4/9] iio: adc: mcp3911: use resource-managed version of iio_device_register Marcus Folkesson
` (6 subsequent siblings)
9 siblings, 1 reply; 18+ messages in thread
From: Marcus Folkesson @ 2022-07-04 17:21 UTC (permalink / raw)
To: Marcus Folkesson, Kent Gustavsson, Jonathan Cameron,
Lars-Peter Clausen, Rob Herring, Krzysztof Kozlowski
Cc: linux-iio, devicetree, linux-kernel
The ADC conversion is actually not rail-to-rail but with a factor 1.5.
Make use of this factor when calculating actual voltage.
Fixes: 3a89b289df5d ("iio: adc: add support for mcp3911")
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
---
drivers/iio/adc/mcp3911.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
index f8875076ae80..890af7dca62d 100644
--- a/drivers/iio/adc/mcp3911.c
+++ b/drivers/iio/adc/mcp3911.c
@@ -40,8 +40,8 @@
#define MCP3911_CHANNEL(x) (MCP3911_REG_CHANNEL0 + x * 3)
#define MCP3911_OFFCAL(x) (MCP3911_REG_OFFCAL_CH0 + x * 6)
-/* Internal voltage reference in uV */
-#define MCP3911_INT_VREF_UV 1200000
+/* Internal voltage reference in mV */
+#define MCP3911_INT_VREF_MV 1200
#define MCP3911_REG_READ(reg, id) ((((reg) << 1) | ((id) << 5) | (1 << 0)) & 0xff)
#define MCP3911_REG_WRITE(reg, id) ((((reg) << 1) | ((id) << 5) | (0 << 0)) & 0xff)
@@ -139,11 +139,18 @@ static int mcp3911_read_raw(struct iio_dev *indio_dev,
*val = ret / 1000;
} else {
- *val = MCP3911_INT_VREF_UV;
+ *val = MCP3911_INT_VREF_MV;
}
- *val2 = 24;
- ret = IIO_VAL_FRACTIONAL_LOG2;
+ /*
+ * 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;
break;
}
--
2.36.1
^ permalink raw reply related [flat|nested] 18+ messages in thread
* Re: [PATCH v3 3/9] iio: adc: mcp3911: use correct formula for AD conversion
2022-07-04 17:21 ` [PATCH v3 3/9] iio: adc: mcp3911: use correct formula for AD conversion Marcus Folkesson
@ 2022-07-16 17:18 ` Jonathan Cameron
2022-07-17 13:58 ` Marcus Folkesson
0 siblings, 1 reply; 18+ messages in thread
From: Jonathan Cameron @ 2022-07-16 17:18 UTC (permalink / raw)
To: Marcus Folkesson
Cc: Kent Gustavsson, Lars-Peter Clausen, Rob Herring,
Krzysztof Kozlowski, linux-iio, devicetree, linux-kernel
On Mon, 4 Jul 2022 19:21:10 +0200
Marcus Folkesson <marcus.folkesson@gmail.com> wrote:
> The ADC conversion is actually not rail-to-rail but with a factor 1.5.
> Make use of this factor when calculating actual voltage.
>
> Fixes: 3a89b289df5d ("iio: adc: add support for mcp3911")
> Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
> Acked-by: Jonathan Cameron <jic23@kernel.org>
? I doubt I gave a tag (mostly because I don't give tags to patches
I'll pick up and give a SoB on.
Note that tags have to be given explicitly in full form before you can
add them to a patch. If in doubt (people often given handwavey responses)
then ask people to give an explicit tag.
Jonathan
> ---
> drivers/iio/adc/mcp3911.c | 17 ++++++++++++-----
> 1 file changed, 12 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
> index f8875076ae80..890af7dca62d 100644
> --- a/drivers/iio/adc/mcp3911.c
> +++ b/drivers/iio/adc/mcp3911.c
> @@ -40,8 +40,8 @@
> #define MCP3911_CHANNEL(x) (MCP3911_REG_CHANNEL0 + x * 3)
> #define MCP3911_OFFCAL(x) (MCP3911_REG_OFFCAL_CH0 + x * 6)
>
> -/* Internal voltage reference in uV */
> -#define MCP3911_INT_VREF_UV 1200000
> +/* Internal voltage reference in mV */
> +#define MCP3911_INT_VREF_MV 1200
>
> #define MCP3911_REG_READ(reg, id) ((((reg) << 1) | ((id) << 5) | (1 << 0)) & 0xff)
> #define MCP3911_REG_WRITE(reg, id) ((((reg) << 1) | ((id) << 5) | (0 << 0)) & 0xff)
> @@ -139,11 +139,18 @@ static int mcp3911_read_raw(struct iio_dev *indio_dev,
>
> *val = ret / 1000;
> } else {
> - *val = MCP3911_INT_VREF_UV;
> + *val = MCP3911_INT_VREF_MV;
> }
>
> - *val2 = 24;
> - ret = IIO_VAL_FRACTIONAL_LOG2;
> + /*
> + * 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;
> break;
> }
>
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v3 3/9] iio: adc: mcp3911: use correct formula for AD conversion
2022-07-16 17:18 ` Jonathan Cameron
@ 2022-07-17 13:58 ` Marcus Folkesson
0 siblings, 0 replies; 18+ messages in thread
From: Marcus Folkesson @ 2022-07-17 13:58 UTC (permalink / raw)
To: Jonathan Cameron
Cc: Kent Gustavsson, Lars-Peter Clausen, Rob Herring,
Krzysztof Kozlowski, linux-iio, devicetree, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 1004 bytes --]
Hi,
On Sat, Jul 16, 2022 at 06:18:37PM +0100, Jonathan Cameron wrote:
> On Mon, 4 Jul 2022 19:21:10 +0200
> Marcus Folkesson <marcus.folkesson@gmail.com> wrote:
>
> > The ADC conversion is actually not rail-to-rail but with a factor 1.5.
> > Make use of this factor when calculating actual voltage.
> >
> > Fixes: 3a89b289df5d ("iio: adc: add support for mcp3911")
> > Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
> > Acked-by: Jonathan Cameron <jic23@kernel.org>
> ? I doubt I gave a tag (mostly because I don't give tags to patches
> I'll pick up and give a SoB on.
>
> Note that tags have to be given explicitly in full form before you can
> add them to a patch. If in doubt (people often given handwavey responses)
> then ask people to give an explicit tag.
Sorry for that. I will remove the tag.
I interpreted your "Otherwise looks good to me." as an acked-by.
I will only go for explicit tags forward.
Thanks,
Marcus Folkesson
>
> Jonathan
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH v3 4/9] iio: adc: mcp3911: use resource-managed version of iio_device_register
2022-07-04 17:21 [PATCH v3 0/9] Improve MCP3911 driver Marcus Folkesson
` (2 preceding siblings ...)
2022-07-04 17:21 ` [PATCH v3 3/9] iio: adc: mcp3911: use correct formula for AD conversion Marcus Folkesson
@ 2022-07-04 17:21 ` Marcus Folkesson
2022-07-16 17:22 ` Jonathan Cameron
2022-07-04 17:21 ` [PATCH v3 5/9] iio: adc: mcp3911: add support for buffers Marcus Folkesson
` (5 subsequent siblings)
9 siblings, 1 reply; 18+ messages in thread
From: Marcus Folkesson @ 2022-07-04 17:21 UTC (permalink / raw)
To: Marcus Folkesson, Kent Gustavsson, Jonathan Cameron,
Lars-Peter Clausen, Rob Herring, Krzysztof Kozlowski
Cc: linux-iio, devicetree, linux-kernel
Keep using managed resources as much as possible.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
---
drivers/iio/adc/mcp3911.c | 43 ++++++++++++++++-----------------------
1 file changed, 18 insertions(+), 25 deletions(-)
diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
index 890af7dca62d..f5fd9da6ab55 100644
--- a/drivers/iio/adc/mcp3911.c
+++ b/drivers/iio/adc/mcp3911.c
@@ -258,6 +258,16 @@ static int mcp3911_config(struct mcp3911 *adc)
return mcp3911_write(adc, MCP3911_REG_CONFIG, configreg, 2);
}
+static void mcp3911_cleanup(void *_adc)
+{
+ struct mcp3911 *adc = _adc;
+
+ if (adc->clki)
+ clk_disable_unprepare(adc->clki);
+ if (adc->vref)
+ regulator_disable(adc->vref);
+}
+
static int mcp3911_probe(struct spi_device *spi)
{
struct iio_dev *indio_dev;
@@ -271,6 +281,10 @@ static int mcp3911_probe(struct spi_device *spi)
adc = iio_priv(indio_dev);
adc->spi = spi;
+ ret = devm_add_action_or_reset(&spi->dev, mcp3911_cleanup, adc);
+ if (ret)
+ return ret;
+
adc->vref = devm_regulator_get_optional(&adc->spi->dev, "vref");
if (IS_ERR(adc->vref)) {
if (PTR_ERR(adc->vref) == -ENODEV) {
@@ -296,21 +310,20 @@ static int mcp3911_probe(struct spi_device *spi)
dev_err(&adc->spi->dev,
"failed to get adc clk (%ld)\n",
PTR_ERR(adc->clki));
- ret = PTR_ERR(adc->clki);
- goto reg_disable;
+ return PTR_ERR(adc->clki);
}
} else {
ret = clk_prepare_enable(adc->clki);
if (ret < 0) {
dev_err(&adc->spi->dev,
"Failed to enable clki: %d\n", ret);
- goto reg_disable;
+ return ret;
}
}
ret = mcp3911_config(adc);
if (ret)
- goto clk_disable;
+ return ret;
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->modes = INDIO_DIRECT_MODE;
@@ -322,31 +335,11 @@ static int mcp3911_probe(struct spi_device *spi)
mutex_init(&adc->lock);
- ret = iio_device_register(indio_dev);
- if (ret)
- goto clk_disable;
-
- return ret;
-
-clk_disable:
- clk_disable_unprepare(adc->clki);
-reg_disable:
- if (adc->vref)
- regulator_disable(adc->vref);
-
- return ret;
+ return devm_iio_device_register(&adc->spi->dev, indio_dev);
}
static void mcp3911_remove(struct spi_device *spi)
{
- struct iio_dev *indio_dev = spi_get_drvdata(spi);
- struct mcp3911 *adc = iio_priv(indio_dev);
-
- iio_device_unregister(indio_dev);
-
- clk_disable_unprepare(adc->clki);
- if (adc->vref)
- regulator_disable(adc->vref);
}
static const struct of_device_id mcp3911_dt_ids[] = {
--
2.36.1
^ permalink raw reply related [flat|nested] 18+ messages in thread
* Re: [PATCH v3 4/9] iio: adc: mcp3911: use resource-managed version of iio_device_register
2022-07-04 17:21 ` [PATCH v3 4/9] iio: adc: mcp3911: use resource-managed version of iio_device_register Marcus Folkesson
@ 2022-07-16 17:22 ` Jonathan Cameron
0 siblings, 0 replies; 18+ messages in thread
From: Jonathan Cameron @ 2022-07-16 17:22 UTC (permalink / raw)
To: Marcus Folkesson
Cc: Kent Gustavsson, Lars-Peter Clausen, Rob Herring,
Krzysztof Kozlowski, linux-iio, devicetree, linux-kernel
On Mon, 4 Jul 2022 19:21:11 +0200
Marcus Folkesson <marcus.folkesson@gmail.com> wrote:
> Keep using managed resources as much as possible.
>
> Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
> ---
> drivers/iio/adc/mcp3911.c | 43 ++++++++++++++++-----------------------
> 1 file changed, 18 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
> index 890af7dca62d..f5fd9da6ab55 100644
> --- a/drivers/iio/adc/mcp3911.c
> +++ b/drivers/iio/adc/mcp3911.c
> @@ -258,6 +258,16 @@ static int mcp3911_config(struct mcp3911 *adc)
> return mcp3911_write(adc, MCP3911_REG_CONFIG, configreg, 2);
> }
>
> +static void mcp3911_cleanup(void *_adc)
Very rarely a good idea to cleanup more than one thing in a given
devm_ callback.
> +{
> + struct mcp3911 *adc = _adc;
> +
> + if (adc->clki)
> + clk_disable_unprepare(adc->clki);
> + if (adc->vref)
> + regulator_disable(adc->vref);
> +}
> +
> static int mcp3911_probe(struct spi_device *spi)
> {
> struct iio_dev *indio_dev;
> @@ -271,6 +281,10 @@ static int mcp3911_probe(struct spi_device *spi)
> adc = iio_priv(indio_dev);
> adc->spi = spi;
>
> + ret = devm_add_action_or_reset(&spi->dev, mcp3911_cleanup, adc);
> + if (ret)
> + return ret;
You should only register this 'after' what it cleans up. I want to see
a clear pairing between setup and tear down.
In this particular case register two callbacks, and only register them
if they have anything to do. i.e. the ->clki and ->vref are not null
respectively.
Jonathan
> +
> adc->vref = devm_regulator_get_optional(&adc->spi->dev, "vref");
> if (IS_ERR(adc->vref)) {
> if (PTR_ERR(adc->vref) == -ENODEV) {
> @@ -296,21 +310,20 @@ static int mcp3911_probe(struct spi_device *spi)
> dev_err(&adc->spi->dev,
> "failed to get adc clk (%ld)\n",
> PTR_ERR(adc->clki));
> - ret = PTR_ERR(adc->clki);
> - goto reg_disable;
> + return PTR_ERR(adc->clki);
> }
> } else {
> ret = clk_prepare_enable(adc->clki);
> if (ret < 0) {
> dev_err(&adc->spi->dev,
> "Failed to enable clki: %d\n", ret);
> - goto reg_disable;
> + return ret;
> }
> }
>
> ret = mcp3911_config(adc);
> if (ret)
> - goto clk_disable;
> + return ret;
>
> indio_dev->name = spi_get_device_id(spi)->name;
> indio_dev->modes = INDIO_DIRECT_MODE;
> @@ -322,31 +335,11 @@ static int mcp3911_probe(struct spi_device *spi)
>
> mutex_init(&adc->lock);
>
> - ret = iio_device_register(indio_dev);
> - if (ret)
> - goto clk_disable;
> -
> - return ret;
> -
> -clk_disable:
> - clk_disable_unprepare(adc->clki);
> -reg_disable:
> - if (adc->vref)
> - regulator_disable(adc->vref);
> -
> - return ret;
> + return devm_iio_device_register(&adc->spi->dev, indio_dev);
> }
>
> static void mcp3911_remove(struct spi_device *spi)
> {
> - struct iio_dev *indio_dev = spi_get_drvdata(spi);
> - struct mcp3911 *adc = iio_priv(indio_dev);
> -
> - iio_device_unregister(indio_dev);
> -
> - clk_disable_unprepare(adc->clki);
> - if (adc->vref)
> - regulator_disable(adc->vref);
> }
>
> static const struct of_device_id mcp3911_dt_ids[] = {
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH v3 5/9] iio: adc: mcp3911: add support for buffers
2022-07-04 17:21 [PATCH v3 0/9] Improve MCP3911 driver Marcus Folkesson
` (3 preceding siblings ...)
2022-07-04 17:21 ` [PATCH v3 4/9] iio: adc: mcp3911: use resource-managed version of iio_device_register Marcus Folkesson
@ 2022-07-04 17:21 ` Marcus Folkesson
2022-07-04 21:56 ` Andy Shevchenko
2022-07-04 17:21 ` [PATCH v3 6/9] iio: adc: mcp3911: add support for interrupts Marcus Folkesson
` (4 subsequent siblings)
9 siblings, 1 reply; 18+ messages in thread
From: Marcus Folkesson @ 2022-07-04 17:21 UTC (permalink / raw)
To: Marcus Folkesson, Kent Gustavsson, Jonathan Cameron,
Lars-Peter Clausen, Rob Herring, Krzysztof Kozlowski
Cc: linux-iio, devicetree, linux-kernel
Add support for buffers to make the driver fit for more usecases.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
---
drivers/iio/adc/mcp3911.c | 99 ++++++++++++++++++++++++++++++++++++---
1 file changed, 92 insertions(+), 7 deletions(-)
diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
index f5fd9da6ab55..cf4dacc7de06 100644
--- a/drivers/iio/adc/mcp3911.c
+++ b/drivers/iio/adc/mcp3911.c
@@ -5,10 +5,16 @@
* Copyright (C) 2018 Marcus Folkesson <marcus.folkesson@gmail.com>
* Copyright (C) 2018 Kent Gustavsson <kent@minoris.se>
*/
+#include <linux/bitfield.h>
+#include <linux/bits.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/trigger.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/property.h>
@@ -22,6 +28,7 @@
#define MCP3911_REG_GAIN 0x09
#define MCP3911_REG_STATUSCOM 0x0a
+#define MCP3911_STATUSCOM_READ GENMASK(7, 6)
#define MCP3911_STATUSCOM_CH1_24WIDTH BIT(4)
#define MCP3911_STATUSCOM_CH0_24WIDTH BIT(3)
#define MCP3911_STATUSCOM_EN_OFFCAL BIT(2)
@@ -54,6 +61,13 @@ struct mcp3911 {
struct regulator *vref;
struct clk *clki;
u32 dev_addr;
+ struct {
+ u32 channels[MCP3911_NUM_CHANNELS];
+ s64 ts __aligned(8);
+ } scan;
+
+ u8 tx_buf[MCP3911_NUM_CHANNELS * 3] __aligned(IIO_DMA_MINALIGN);
+ u8 rx_buf[MCP3911_NUM_CHANNELS * 3];
};
static int mcp3911_read(struct mcp3911 *adc, u8 reg, u32 *val, u8 len)
@@ -196,16 +210,66 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
.type = IIO_VOLTAGE, \
.indexed = 1, \
.channel = idx, \
+ .scan_index = idx, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_OFFSET) | \
BIT(IIO_CHAN_INFO_SCALE), \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = 24, \
+ .storagebits = 32, \
+ }, \
}
static const struct iio_chan_spec mcp3911_channels[] = {
MCP3911_CHAN(0),
MCP3911_CHAN(1),
+ IIO_CHAN_SOFT_TIMESTAMP(2),
};
+static irqreturn_t mcp3911_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct mcp3911 *adc = iio_priv(indio_dev);
+ struct spi_transfer xfer = {
+ .tx_buf = adc->tx_buf,
+ .rx_buf = adc->rx_buf,
+ .len = sizeof(adc->rx_buf),
+ };
+ int scan_index;
+ int i = 0;
+ int ret;
+
+ mutex_lock(&adc->lock);
+ adc->tx_buf[0] = MCP3911_REG_READ(MCP3911_CHANNEL(0), adc->dev_addr);
+ ret = spi_sync_transfer(adc->spi, &xfer, 1);
+ if (ret < 0) {
+ dev_warn(&adc->spi->dev,
+ "failed to get conversion data\n");
+ goto out;
+ }
+
+ for_each_set_bit(scan_index, indio_dev->active_scan_mask,
+ indio_dev->masklength) {
+ const struct iio_chan_spec *scan_chan =
+ &indio_dev->channels[scan_index];
+
+ adc->scan.channels[i] = adc->rx_buf[scan_chan->channel * 3 + 0] << 16 |
+ adc->rx_buf[scan_chan->channel * 3 + 1] << 8 |
+ adc->rx_buf[scan_chan->channel * 3 + 2] << 0;
+
+ i++;
+ }
+ iio_push_to_buffers_with_timestamp(indio_dev, &adc->scan,
+ iio_get_time_ns(indio_dev));
+out:
+ mutex_unlock(&adc->lock);
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
static const struct iio_info mcp3911_info = {
.read_raw = mcp3911_read_raw,
.write_raw = mcp3911_write_raw,
@@ -214,7 +278,7 @@ static const struct iio_info mcp3911_info = {
static int mcp3911_config(struct mcp3911 *adc)
{
struct device *dev = &adc->spi->dev;
- u32 configreg;
+ u32 regval;
int ret;
ret = device_property_read_u32(dev, "microchip,device-addr", &adc->dev_addr);
@@ -233,29 +297,43 @@ static int mcp3911_config(struct mcp3911 *adc)
}
dev_dbg(&adc->spi->dev, "use device address %i\n", adc->dev_addr);
- ret = mcp3911_read(adc, MCP3911_REG_CONFIG, &configreg, 2);
+ ret = mcp3911_read(adc, MCP3911_REG_CONFIG, ®val, 2);
if (ret)
return ret;
+ regval &= ~MCP3911_CONFIG_VREFEXT;
if (adc->vref) {
dev_dbg(&adc->spi->dev, "use external voltage reference\n");
- configreg |= MCP3911_CONFIG_VREFEXT;
+ regval |= FIELD_PREP(MCP3911_CONFIG_VREFEXT, 1);
} else {
dev_dbg(&adc->spi->dev,
"use internal voltage reference (1.2V)\n");
- configreg &= ~MCP3911_CONFIG_VREFEXT;
+ regval |= FIELD_PREP(MCP3911_CONFIG_VREFEXT, 0);
}
+ regval &= ~MCP3911_CONFIG_CLKEXT;
if (adc->clki) {
dev_dbg(&adc->spi->dev, "use external clock as clocksource\n");
- configreg |= MCP3911_CONFIG_CLKEXT;
+ regval |= FIELD_PREP(MCP3911_CONFIG_CLKEXT, 1);
} else {
dev_dbg(&adc->spi->dev,
"use crystal oscillator as clocksource\n");
- configreg &= ~MCP3911_CONFIG_CLKEXT;
+ regval |= FIELD_PREP(MCP3911_CONFIG_CLKEXT, 0);
}
- return mcp3911_write(adc, MCP3911_REG_CONFIG, configreg, 2);
+ ret = mcp3911_write(adc, MCP3911_REG_CONFIG, regval, 2);
+ if (ret)
+ return ret;
+
+ ret = mcp3911_read(adc, MCP3911_REG_STATUSCOM, ®val, 2);
+ if (ret)
+ return ret;
+
+ /* Address counter incremented, cycle through register types */
+ regval &= ~MCP3911_STATUSCOM_READ;
+ regval |= FIELD_PREP(MCP3911_STATUSCOM_READ, 0x02);
+
+ return mcp3911_write(adc, MCP3911_REG_STATUSCOM, regval, 2);
}
static void mcp3911_cleanup(void *_adc)
@@ -325,6 +403,7 @@ static int mcp3911_probe(struct spi_device *spi)
if (ret)
return ret;
+
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->info = &mcp3911_info;
@@ -335,6 +414,12 @@ static int mcp3911_probe(struct spi_device *spi)
mutex_init(&adc->lock);
+ ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
+ NULL,
+ mcp3911_trigger_handler, NULL);
+ if (ret)
+ return ret;
+
return devm_iio_device_register(&adc->spi->dev, indio_dev);
}
--
2.36.1
^ permalink raw reply related [flat|nested] 18+ messages in thread
* Re: [PATCH v3 5/9] iio: adc: mcp3911: add support for buffers
2022-07-04 17:21 ` [PATCH v3 5/9] iio: adc: mcp3911: add support for buffers Marcus Folkesson
@ 2022-07-04 21:56 ` Andy Shevchenko
0 siblings, 0 replies; 18+ messages in thread
From: Andy Shevchenko @ 2022-07-04 21:56 UTC (permalink / raw)
To: Marcus Folkesson
Cc: Kent Gustavsson, Jonathan Cameron, Lars-Peter Clausen,
Rob Herring, Krzysztof Kozlowski, linux-iio, devicetree,
Linux Kernel Mailing List
On Mon, Jul 4, 2022 at 7:20 PM Marcus Folkesson
<marcus.folkesson@gmail.com> wrote:
>
> Add support for buffers to make the driver fit for more usecases.
use cases
...
> + for_each_set_bit(scan_index, indio_dev->active_scan_mask,
> + indio_dev->masklength) {
> + const struct iio_chan_spec *scan_chan =
> + &indio_dev->channels[scan_index];
> +
> + adc->scan.channels[i] = adc->rx_buf[scan_chan->channel * 3 + 0] << 16 |
> + adc->rx_buf[scan_chan->channel * 3 + 1] << 8 |
> + adc->rx_buf[scan_chan->channel * 3 + 2] << 0;
get_unaligned_be24()
> + i++;
> + }
...
> @@ -325,6 +403,7 @@ static int mcp3911_probe(struct spi_device *spi)
> if (ret)
> return ret;
>
> +
> indio_dev->name = spi_get_device_id(spi)->name;
> indio_dev->modes = INDIO_DIRECT_MODE;
> indio_dev->info = &mcp3911_info;
Stray change.
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH v3 6/9] iio: adc: mcp3911: add support for interrupts
2022-07-04 17:21 [PATCH v3 0/9] Improve MCP3911 driver Marcus Folkesson
` (4 preceding siblings ...)
2022-07-04 17:21 ` [PATCH v3 5/9] iio: adc: mcp3911: add support for buffers Marcus Folkesson
@ 2022-07-04 17:21 ` Marcus Folkesson
2022-07-04 21:57 ` Andy Shevchenko
2022-07-04 17:21 ` [PATCH v3 7/9] dt-bindings: iio: adc: mcp3911: add microchip,data-ready-hiz entry Marcus Folkesson
` (3 subsequent siblings)
9 siblings, 1 reply; 18+ messages in thread
From: Marcus Folkesson @ 2022-07-04 17:21 UTC (permalink / raw)
To: Marcus Folkesson, Kent Gustavsson, Jonathan Cameron,
Lars-Peter Clausen, Rob Herring, Krzysztof Kozlowski
Cc: linux-iio, devicetree, linux-kernel
Make it possible to read values upon interrupts.
Configure Data Ready Signal Output Pin to either HiZ or push-pull and
use it as interrupt source.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
---
drivers/iio/adc/mcp3911.c | 52 +++++++++++++++++++++++++++++++++++++++
1 file changed, 52 insertions(+)
diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
index cf4dacc7de06..9c6f456bdbdf 100644
--- a/drivers/iio/adc/mcp3911.c
+++ b/drivers/iio/adc/mcp3911.c
@@ -28,6 +28,7 @@
#define MCP3911_REG_GAIN 0x09
#define MCP3911_REG_STATUSCOM 0x0a
+#define MCP3911_STATUSCOM_DRHIZ BIT(12)
#define MCP3911_STATUSCOM_READ GENMASK(7, 6)
#define MCP3911_STATUSCOM_CH1_24WIDTH BIT(4)
#define MCP3911_STATUSCOM_CH0_24WIDTH BIT(3)
@@ -61,6 +62,7 @@ struct mcp3911 {
struct regulator *vref;
struct clk *clki;
u32 dev_addr;
+ struct iio_trigger *trig;
struct {
u32 channels[MCP3911_NUM_CHANNELS];
s64 ts __aligned(8);
@@ -346,6 +348,23 @@ static void mcp3911_cleanup(void *_adc)
regulator_disable(adc->vref);
}
+static int mcp3911_set_trigger_state(struct iio_trigger *trig, bool enable)
+{
+ struct mcp3911 *adc = iio_trigger_get_drvdata(trig);
+
+ if (enable)
+ enable_irq(adc->spi->irq);
+ else
+ disable_irq(adc->spi->irq);
+
+ return 0;
+}
+
+static const struct iio_trigger_ops mcp3911_trigger_ops = {
+ .validate_device = iio_trigger_validate_own_device,
+ .set_trigger_state = mcp3911_set_trigger_state,
+};
+
static int mcp3911_probe(struct spi_device *spi)
{
struct iio_dev *indio_dev;
@@ -403,6 +422,14 @@ static int mcp3911_probe(struct spi_device *spi)
if (ret)
return ret;
+ if (device_property_read_bool(&adc->spi->dev, "microchip,data-ready-hiz"))
+ ret = mcp3911_update(adc, MCP3911_REG_STATUSCOM, MCP3911_STATUSCOM_DRHIZ,
+ 0, 2);
+ else
+ ret = mcp3911_update(adc, MCP3911_REG_STATUSCOM, MCP3911_STATUSCOM_DRHIZ,
+ MCP3911_STATUSCOM_DRHIZ, 2);
+ if (ret)
+ return ret;
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->modes = INDIO_DIRECT_MODE;
@@ -414,6 +441,31 @@ static int mcp3911_probe(struct spi_device *spi)
mutex_init(&adc->lock);
+ if (spi->irq > 0) {
+ adc->trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d",
+ indio_dev->name,
+ iio_device_id(indio_dev));
+ if (!adc->trig)
+ return PTR_ERR(adc->trig);
+
+ adc->trig->ops = &mcp3911_trigger_ops;
+ iio_trigger_set_drvdata(adc->trig, adc);
+ ret = devm_iio_trigger_register(&spi->dev, adc->trig);
+ if (ret)
+ return ret;
+
+ /*
+ * The device generates interrupts as long as it is powered up.
+ * Some platforms might not allow the option to power it down so
+ * don't enable the interrupt to avoid extra load on the system
+ */
+ ret = devm_request_irq(&spi->dev, spi->irq,
+ &iio_trigger_generic_data_rdy_poll, IRQF_NO_AUTOEN | IRQF_ONESHOT,
+ indio_dev->name, adc->trig);
+ if (ret)
+ return ret;
+ }
+
ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
NULL,
mcp3911_trigger_handler, NULL);
--
2.36.1
^ permalink raw reply related [flat|nested] 18+ messages in thread
* Re: [PATCH v3 6/9] iio: adc: mcp3911: add support for interrupts
2022-07-04 17:21 ` [PATCH v3 6/9] iio: adc: mcp3911: add support for interrupts Marcus Folkesson
@ 2022-07-04 21:57 ` Andy Shevchenko
0 siblings, 0 replies; 18+ messages in thread
From: Andy Shevchenko @ 2022-07-04 21:57 UTC (permalink / raw)
To: Marcus Folkesson
Cc: Kent Gustavsson, Jonathan Cameron, Lars-Peter Clausen,
Rob Herring, Krzysztof Kozlowski, linux-iio, devicetree,
Linux Kernel Mailing List
On Mon, Jul 4, 2022 at 7:21 PM Marcus Folkesson
<marcus.folkesson@gmail.com> wrote:
>
> Make it possible to read values upon interrupts.
> Configure Data Ready Signal Output Pin to either HiZ or push-pull and
> use it as interrupt source.
...
> + /*
> + * The device generates interrupts as long as it is powered up.
> + * Some platforms might not allow the option to power it down so
> + * don't enable the interrupt to avoid extra load on the system
Missed period.
> + */
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH v3 7/9] dt-bindings: iio: adc: mcp3911: add microchip,data-ready-hiz entry
2022-07-04 17:21 [PATCH v3 0/9] Improve MCP3911 driver Marcus Folkesson
` (5 preceding siblings ...)
2022-07-04 17:21 ` [PATCH v3 6/9] iio: adc: mcp3911: add support for interrupts Marcus Folkesson
@ 2022-07-04 17:21 ` Marcus Folkesson
2022-07-04 17:21 ` [PATCH v3 8/9] iio: adc: mcp3911: add support for oversampling ratio Marcus Folkesson
` (2 subsequent siblings)
9 siblings, 0 replies; 18+ messages in thread
From: Marcus Folkesson @ 2022-07-04 17:21 UTC (permalink / raw)
To: Marcus Folkesson, Kent Gustavsson, Jonathan Cameron,
Lars-Peter Clausen, Rob Herring, Krzysztof Kozlowski
Cc: linux-iio, devicetree, linux-kernel, Krzysztof Kozlowski
The Data Ready Output Pin is either hard wired to work as high
impedance or push-pull. Make it configurable.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
.../devicetree/bindings/iio/adc/microchip,mcp3911.yaml | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/Documentation/devicetree/bindings/iio/adc/microchip,mcp3911.yaml b/Documentation/devicetree/bindings/iio/adc/microchip,mcp3911.yaml
index 95ab285f4eba..57a16380f864 100644
--- a/Documentation/devicetree/bindings/iio/adc/microchip,mcp3911.yaml
+++ b/Documentation/devicetree/bindings/iio/adc/microchip,mcp3911.yaml
@@ -36,6 +36,13 @@ properties:
description: IRQ line of the ADC
maxItems: 1
+ microchip,data-ready-hiz:
+ description:
+ Data Ready Pin Inactive State Control
+ true = The DR pin state is high-impedance when data are NOT ready
+ false = The DR pin state is a logic high when data are NOT ready
+ type: boolean
+
microchip,device-addr:
description: Device address when multiple MCP3911 chips are present on the same SPI bus.
$ref: /schemas/types.yaml#/definitions/uint32
--
2.36.1
^ permalink raw reply related [flat|nested] 18+ messages in thread
* [PATCH v3 8/9] iio: adc: mcp3911: add support for oversampling ratio
2022-07-04 17:21 [PATCH v3 0/9] Improve MCP3911 driver Marcus Folkesson
` (6 preceding siblings ...)
2022-07-04 17:21 ` [PATCH v3 7/9] dt-bindings: iio: adc: mcp3911: add microchip,data-ready-hiz entry Marcus Folkesson
@ 2022-07-04 17:21 ` Marcus Folkesson
2022-07-04 21:58 ` Andy Shevchenko
2022-07-04 17:21 ` [PATCH v3 9/9] iio: adc: mcp3911: add support to set PGA Marcus Folkesson
2022-07-04 22:03 ` [PATCH v3 0/9] Improve MCP3911 driver Andy Shevchenko
9 siblings, 1 reply; 18+ messages in thread
From: Marcus Folkesson @ 2022-07-04 17:21 UTC (permalink / raw)
To: Marcus Folkesson, Kent Gustavsson, Jonathan Cameron,
Lars-Peter Clausen, Rob Herring, Krzysztof Kozlowski
Cc: linux-iio, devicetree, linux-kernel
The chip supports oversampling ratio, so expose it to userspace.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
---
drivers/iio/adc/mcp3911.c | 59 +++++++++++++++++++++++++++++++++++++++
1 file changed, 59 insertions(+)
diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
index 9c6f456bdbdf..c6e30471bb81 100644
--- a/drivers/iio/adc/mcp3911.c
+++ b/drivers/iio/adc/mcp3911.c
@@ -38,6 +38,7 @@
#define MCP3911_REG_CONFIG 0x0c
#define MCP3911_CONFIG_CLKEXT BIT(1)
#define MCP3911_CONFIG_VREFEXT BIT(2)
+#define MCP3911_CONFIG_OSR GENMASK(13, 11)
#define MCP3911_REG_OFFCAL_CH0 0x0e
#define MCP3911_REG_GAINCAL_CH0 0x11
@@ -56,6 +57,8 @@
#define MCP3911_NUM_CHANNELS 2
+static const int mcp3911_osr_table[] = { 32, 64, 128, 256, 512, 1024, 2048, 4096 };
+
struct mcp3911 {
struct spi_device *spi;
struct mutex lock;
@@ -114,6 +117,36 @@ static int mcp3911_update(struct mcp3911 *adc, u8 reg, u32 mask,
return mcp3911_write(adc, reg, val, len);
}
+static int mcp3911_write_raw_get_fmt(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ long mask)
+{
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ return IIO_VAL_INT_PLUS_NANO;
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ return IIO_VAL_INT;
+ default:
+ return IIO_VAL_INT_PLUS_NANO;
+ }
+}
+
+static int mcp3911_read_avail(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ const int **vals, int *type, int *length,
+ long info)
+{
+ switch (info) {
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ *type = IIO_VAL_INT;
+ *vals = mcp3911_osr_table;
+ *length = ARRAY_SIZE(mcp3911_osr_table);
+ return IIO_AVAIL_LIST;
+ default:
+ return -EINVAL;
+ }
+}
+
static int mcp3911_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *channel, int *val,
int *val2, long mask)
@@ -142,6 +175,16 @@ static int mcp3911_read_raw(struct iio_dev *indio_dev,
ret = IIO_VAL_INT;
break;
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ ret = mcp3911_read(adc,
+ MCP3911_REG_CONFIG, val, 2);
+ if (ret)
+ goto out;
+
+ *val = FIELD_GET(MCP3911_CONFIG_OSR, *val);
+ *val = 32 << *val;
+ ret = IIO_VAL_INT;
+ break;
case IIO_CHAN_INFO_SCALE:
if (adc->vref) {
@@ -201,6 +244,17 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
MCP3911_STATUSCOM_EN_OFFCAL,
MCP3911_STATUSCOM_EN_OFFCAL, 2);
break;
+
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ for (int i = 0; i < sizeof(mcp3911_osr_table); i++) {
+ if (val == mcp3911_osr_table[i]) {
+ val = FIELD_PREP(MCP3911_CONFIG_OSR, i);
+ ret = mcp3911_update(adc, MCP3911_REG_CONFIG, MCP3911_CONFIG_OSR,
+ val, 2);
+ break;
+ }
+ }
+ break;
}
out:
@@ -213,9 +267,12 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
.indexed = 1, \
.channel = idx, \
.scan_index = idx, \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_OFFSET) | \
BIT(IIO_CHAN_INFO_SCALE), \
+ .info_mask_shared_by_type_available = \
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
.scan_type = { \
.sign = 's', \
.realbits = 24, \
@@ -275,6 +332,8 @@ static irqreturn_t mcp3911_trigger_handler(int irq, void *p)
static const struct iio_info mcp3911_info = {
.read_raw = mcp3911_read_raw,
.write_raw = mcp3911_write_raw,
+ .read_avail = mcp3911_read_avail,
+ .write_raw_get_fmt = mcp3911_write_raw_get_fmt,
};
static int mcp3911_config(struct mcp3911 *adc)
--
2.36.1
^ permalink raw reply related [flat|nested] 18+ messages in thread
* Re: [PATCH v3 8/9] iio: adc: mcp3911: add support for oversampling ratio
2022-07-04 17:21 ` [PATCH v3 8/9] iio: adc: mcp3911: add support for oversampling ratio Marcus Folkesson
@ 2022-07-04 21:58 ` Andy Shevchenko
0 siblings, 0 replies; 18+ messages in thread
From: Andy Shevchenko @ 2022-07-04 21:58 UTC (permalink / raw)
To: Marcus Folkesson
Cc: Kent Gustavsson, Jonathan Cameron, Lars-Peter Clausen,
Rob Herring, Krzysztof Kozlowski, linux-iio, devicetree,
Linux Kernel Mailing List
On Mon, Jul 4, 2022 at 7:22 PM Marcus Folkesson
<marcus.folkesson@gmail.com> wrote:
>
> The chip supports oversampling ratio, so expose it to userspace.
...
> + ret = mcp3911_read(adc,
> + MCP3911_REG_CONFIG, val, 2);
One line?
> + if (ret)
> + goto out;
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 18+ messages in thread
* [PATCH v3 9/9] iio: adc: mcp3911: add support to set PGA
2022-07-04 17:21 [PATCH v3 0/9] Improve MCP3911 driver Marcus Folkesson
` (7 preceding siblings ...)
2022-07-04 17:21 ` [PATCH v3 8/9] iio: adc: mcp3911: add support for oversampling ratio Marcus Folkesson
@ 2022-07-04 17:21 ` Marcus Folkesson
2022-07-04 22:02 ` Andy Shevchenko
2022-07-04 22:03 ` [PATCH v3 0/9] Improve MCP3911 driver Andy Shevchenko
9 siblings, 1 reply; 18+ messages in thread
From: Marcus Folkesson @ 2022-07-04 17:21 UTC (permalink / raw)
To: Marcus Folkesson, Kent Gustavsson, Jonathan Cameron,
Lars-Peter Clausen, Rob Herring, Krzysztof Kozlowski
Cc: linux-iio, devicetree, linux-kernel
Add support for setting the Programmable Gain Amplifiers by adjust the
scale value.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
---
drivers/iio/adc/mcp3911.c | 107 +++++++++++++++++++++++++++++---------
1 file changed, 83 insertions(+), 24 deletions(-)
diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
index c6e30471bb81..7fc53f0057d6 100644
--- a/drivers/iio/adc/mcp3911.c
+++ b/drivers/iio/adc/mcp3911.c
@@ -26,6 +26,8 @@
#define MCP3911_REG_MOD 0x06
#define MCP3911_REG_PHASE 0x07
#define MCP3911_REG_GAIN 0x09
+#define MCP3911_GAIN_MASK(ch) (0x7 << 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)
@@ -56,8 +58,10 @@
#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;
@@ -66,6 +70,7 @@ 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);
@@ -142,6 +147,11 @@ 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;
}
@@ -187,29 +197,9 @@ 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;
}
@@ -227,6 +217,18 @@ 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;
@@ -262,6 +264,47 @@ 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;
+ int tmp0, tmp1;
+ s64 tmp2;
+
+ 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 24bit 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);
+ tmp2 = div_s64((s64)ref * 1000000000LL, div);
+ tmp1 = div;
+ tmp0 = (int)div_s64_rem(tmp2, 1000000000, &tmp1);
+
+ mcp3911_scale_table[i][0] = 0;
+ mcp3911_scale_table[i][1] = tmp1;
+ }
+
+ return 0;
+}
+
#define MCP3911_CHAN(idx) { \
.type = IIO_VOLTAGE, \
.indexed = 1, \
@@ -271,8 +314,10 @@ 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, \
@@ -490,6 +535,20 @@ 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 a known value (1) */
+ 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;
--
2.36.1
^ permalink raw reply related [flat|nested] 18+ messages in thread
* Re: [PATCH v3 9/9] iio: adc: mcp3911: add support to set PGA
2022-07-04 17:21 ` [PATCH v3 9/9] iio: adc: mcp3911: add support to set PGA Marcus Folkesson
@ 2022-07-04 22:02 ` Andy Shevchenko
0 siblings, 0 replies; 18+ messages in thread
From: Andy Shevchenko @ 2022-07-04 22:02 UTC (permalink / raw)
To: Marcus Folkesson
Cc: Kent Gustavsson, Jonathan Cameron, Lars-Peter Clausen,
Rob Herring, Krzysztof Kozlowski, linux-iio, devicetree,
Linux Kernel Mailing List
On Mon, Jul 4, 2022 at 7:23 PM Marcus Folkesson
<marcus.folkesson@gmail.com> wrote:
>
> Add support for setting the Programmable Gain Amplifiers by adjust the
> scale value.
...
> +#define MCP3911_GAIN_MASK(ch) (0x7 << 3 * ch)
GENMASK()
...
> + /*
> + * For 24bit Conversion
24-bit
> + * 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
> + */
...
> + /* Set gain to a known value (1) */
What is '(1)'? In parentheses we usually refer to something like a
formula somewhere.
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 18+ messages in thread
* Re: [PATCH v3 0/9] Improve MCP3911 driver
2022-07-04 17:21 [PATCH v3 0/9] Improve MCP3911 driver Marcus Folkesson
` (8 preceding siblings ...)
2022-07-04 17:21 ` [PATCH v3 9/9] iio: adc: mcp3911: add support to set PGA Marcus Folkesson
@ 2022-07-04 22:03 ` Andy Shevchenko
9 siblings, 0 replies; 18+ messages in thread
From: Andy Shevchenko @ 2022-07-04 22:03 UTC (permalink / raw)
To: Marcus Folkesson
Cc: Kent Gustavsson, Jonathan Cameron, Lars-Peter Clausen,
Rob Herring, Krzysztof Kozlowski, linux-iio, devicetree,
Linux Kernel Mailing List
On Mon, Jul 4, 2022 at 7:20 PM Marcus Folkesson
<marcus.folkesson@gmail.com> wrote:
>
> Hi,
>
> This patch series intend to fix bugs and add functionality to the
> MCP3911 driver.
> The main features added are
> - Support for buffers
> - Interrupt driven readings
> - Support for oversampling ratio
> - Support for set scale values (Gain)
>
> Among the bug fixes, there are changes in the formula for calculate raw
> value and a fix for mismatch in the devicetree property.
>
> Another general improvement for the driver is to use managed resources
> for all allocated resources.
>
> See patch notes for more specific changes between versions.
>
> General changes for the series:
For non-commented patches (excluding patch 7!)
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
For commented ones, you may take the tag if you are going to address
them as suggested.
> v3:
> - Drop Phase patch
> - Add Fixes tags for those patches that are fixes
> - Move Fixes patches to the beginning of the patchset
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 18+ messages in thread