Hi,
The Renesas X9250 integrated four digitally controlled potentiometers.
On each potentiometer, the X9250T has a 100 kOhms total resistance and
the X9250U has a 50 kOhms total resistance.
Best regards,
Herve Codina
Herve Codina (3):
dt-bindings: iio: potentiometer: Add the Renesas X9250 potentiometers
iio: potentiometer: Add support for the Renesas X9250 potentiometers
MAINTAINERS: add the Renesas X9250 driver entry
.../iio/potentiometer/renesas,x9250.yaml | 56 +++++
MAINTAINERS | 7 +
drivers/iio/potentiometer/Kconfig | 10 +
drivers/iio/potentiometer/Makefile | 1 +
drivers/iio/potentiometer/x9250.c | 233 ++++++++++++++++++
5 files changed, 307 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/potentiometer/renesas,x9250.yaml
create mode 100644 drivers/iio/potentiometer/x9250.c
--
2.39.2
The Renesas X9250 integrates four digitally controlled potentiometers.
On each potentiometer, the X9250T has a 100 kOhms total resistance and
the X9250U has a 50 kOhms total resistance.
Signed-off-by: Herve Codina <[email protected]>
---
drivers/iio/potentiometer/Kconfig | 10 ++
drivers/iio/potentiometer/Makefile | 1 +
drivers/iio/potentiometer/x9250.c | 233 +++++++++++++++++++++++++++++
3 files changed, 244 insertions(+)
create mode 100644 drivers/iio/potentiometer/x9250.c
diff --git a/drivers/iio/potentiometer/Kconfig b/drivers/iio/potentiometer/Kconfig
index 01dd3f858d99..e6a9a3c67845 100644
--- a/drivers/iio/potentiometer/Kconfig
+++ b/drivers/iio/potentiometer/Kconfig
@@ -136,4 +136,14 @@ config TPL0102
To compile this driver as a module, choose M here: the
module will be called tpl0102.
+config X9250
+ tristate "Renesas X9250 quad controlled potentiometers"
+ depends on SPI
+ help
+ Enable support for the Renesas X9250 quad controlled
+ potentiometers.
+
+ To compile this driver as a module, choose M here: the module
+ will be called x9250.
+
endmenu
diff --git a/drivers/iio/potentiometer/Makefile b/drivers/iio/potentiometer/Makefile
index 5ebb8e3bbd76..d11fb739176c 100644
--- a/drivers/iio/potentiometer/Makefile
+++ b/drivers/iio/potentiometer/Makefile
@@ -15,3 +15,4 @@ obj-$(CONFIG_MCP4131) += mcp4131.o
obj-$(CONFIG_MCP4531) += mcp4531.o
obj-$(CONFIG_MCP41010) += mcp41010.o
obj-$(CONFIG_TPL0102) += tpl0102.o
+obj-$(CONFIG_X9250) += x9250.o
diff --git a/drivers/iio/potentiometer/x9250.c b/drivers/iio/potentiometer/x9250.c
new file mode 100644
index 000000000000..9d3831f36054
--- /dev/null
+++ b/drivers/iio/potentiometer/x9250.c
@@ -0,0 +1,233 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *
+ * x9250.c -- Renesas X9250 potentiometers IIO driver
+ *
+ * Copyright 2023 CS GROUP France
+ *
+ * Author: Herve Codina <[email protected]>
+ */
+
+#include <linux/iio/iio.h>
+#include <linux/limits.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+
+struct x9250_cfg {
+ int kohms;
+};
+
+struct x9250 {
+ struct spi_device *spi;
+ const struct x9250_cfg *cfg;
+ struct mutex lock; /* Protect tx and rx buffers */
+ /* Cannot use stack area for SPI (dma-safe memory) */
+ u8 spi_tx_buf[3] __aligned(IIO_DMA_MINALIGN);
+ u8 spi_rx_buf[3] __aligned(IIO_DMA_MINALIGN);
+};
+
+#define X9250_CMD_RD_WCR(_p) (0x90 | (_p))
+#define X9250_CMD_WR_WCR(_p) (0xa0 | (_p))
+
+static int x9250_write8(struct x9250 *x9250, u8 cmd, u8 val)
+{
+ struct spi_transfer xfer = {
+ .tx_buf = &x9250->spi_tx_buf,
+ .len = 3,
+ };
+ int ret;
+
+ BUILD_BUG_ON(sizeof(x9250->spi_tx_buf) < 3);
+
+ mutex_lock(&x9250->lock);
+
+ x9250->spi_tx_buf[0] = 0x50;
+ x9250->spi_tx_buf[1] = cmd;
+ x9250->spi_tx_buf[2] = val;
+
+ ret = spi_sync_transfer(x9250->spi, &xfer, 1);
+
+ mutex_unlock(&x9250->lock);
+
+ return ret;
+}
+
+static int x9250_read8(struct x9250 *x9250, u8 cmd, u8 *val)
+{
+ struct spi_transfer xfer = {
+ .tx_buf = &x9250->spi_tx_buf,
+ .rx_buf = &x9250->spi_rx_buf,
+ .len = 3,
+ };
+ int ret;
+
+ BUILD_BUG_ON(sizeof(x9250->spi_tx_buf) < 3);
+ BUILD_BUG_ON(sizeof(x9250->spi_rx_buf) < 3);
+
+ mutex_lock(&x9250->lock);
+
+ x9250->spi_tx_buf[0] = 0x50;
+ x9250->spi_tx_buf[1] = cmd;
+
+ ret = spi_sync_transfer(x9250->spi, &xfer, 1);
+ if (ret)
+ goto end;
+
+ *val = x9250->spi_rx_buf[2];
+ ret = 0;
+end:
+ mutex_unlock(&x9250->lock);
+ return ret;
+}
+
+#define X9250_CHANNEL(ch) { \
+ .type = IIO_RESISTANCE, \
+ .indexed = 1, \
+ .output = 1, \
+ .channel = (ch), \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+ .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_RAW), \
+}
+
+static const struct iio_chan_spec x9250_channels[] = {
+ X9250_CHANNEL(0),
+ X9250_CHANNEL(1),
+ X9250_CHANNEL(2),
+ X9250_CHANNEL(3),
+};
+
+static int x9250_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct x9250 *x9250 = iio_priv(indio_dev);
+ int ch = chan->channel;
+ int ret;
+ u8 v;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ ret = x9250_read8(x9250, X9250_CMD_RD_WCR(ch), &v);
+ if (ret)
+ return ret;
+ *val = v;
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ *val = 1000 * x9250->cfg->kohms;
+ *val2 = U8_MAX;
+ return IIO_VAL_FRACTIONAL;
+ }
+
+ return -EINVAL;
+}
+
+static int x9250_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
+ const int **vals, int *type, int *length, long mask)
+{
+ static const int range[] = {0, 1, 255}; /* min, step, max */
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ *length = ARRAY_SIZE(range);
+ *vals = range;
+ *type = IIO_VAL_INT;
+ return IIO_AVAIL_RANGE;
+ }
+
+ return -EINVAL;
+}
+
+static int x9250_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct x9250 *x9250 = iio_priv(indio_dev);
+ int ch = chan->channel;
+
+ if (mask != IIO_CHAN_INFO_RAW)
+ return -EINVAL;
+
+ if (val > U8_MAX || val < 0)
+ return -EINVAL;
+
+ return x9250_write8(x9250, X9250_CMD_WR_WCR(ch), val);
+}
+
+static const struct iio_info x9250_info = {
+ .read_raw = x9250_read_raw,
+ .read_avail = x9250_read_avail,
+ .write_raw = x9250_write_raw,
+};
+
+enum x9250_type {
+ X9250T,
+ X9250U,
+};
+
+static const struct x9250_cfg x9250_cfg[] = {
+ [X9250T] = { .kohms = 100, },
+ [X9250U] = { .kohms = 50, },
+};
+
+static int x9250_probe(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev;
+ struct x9250 *x9250;
+ int ret;
+
+ spi->bits_per_word = 8;
+ ret = spi_setup(spi);
+ if (ret < 0)
+ return ret;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*x9250));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ x9250 = iio_priv(indio_dev);
+ x9250->spi = spi;
+ x9250->cfg = device_get_match_data(&spi->dev);
+ if (!x9250->cfg)
+ x9250->cfg = &x9250_cfg[spi_get_device_id(spi)->driver_data];
+
+ mutex_init(&x9250->lock);
+
+ indio_dev->info = &x9250_info;
+ indio_dev->channels = x9250_channels;
+ indio_dev->num_channels = ARRAY_SIZE(x9250_channels);
+ indio_dev->name = spi_get_device_id(spi)->name;
+
+ spi_set_drvdata(spi, indio_dev);
+
+ return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct of_device_id x9250_of_match[] = {
+ { .compatible = "renesas,x9250t", &x9250_cfg[X9250T]},
+ { .compatible = "renesas,x9250u", &x9250_cfg[X9250U]},
+ { }
+};
+MODULE_DEVICE_TABLE(of, x9250_of_match);
+
+static const struct spi_device_id x9250_id_table[] = {
+ { "x9250t", X9250T },
+ { "x9250u", X9250U },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, x9250_id_table);
+
+static struct spi_driver x9250_spi_driver = {
+ .driver = {
+ .name = "x9250",
+ .of_match_table = x9250_of_match,
+ },
+ .id_table = x9250_id_table,
+ .probe = x9250_probe,
+};
+
+module_spi_driver(x9250_spi_driver);
+
+MODULE_AUTHOR("Herve Codina <[email protected]>");
+MODULE_DESCRIPTION("X9250 ALSA SoC driver");
+MODULE_LICENSE("GPL");
--
2.39.2
The Renesas X9250 is a quad digitally controlled potentiometers.
Signed-off-by: Herve Codina <[email protected]>
---
.../iio/potentiometer/renesas,x9250.yaml | 56 +++++++++++++++++++
1 file changed, 56 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/potentiometer/renesas,x9250.yaml
diff --git a/Documentation/devicetree/bindings/iio/potentiometer/renesas,x9250.yaml b/Documentation/devicetree/bindings/iio/potentiometer/renesas,x9250.yaml
new file mode 100644
index 000000000000..e0433cd522aa
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/potentiometer/renesas,x9250.yaml
@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/potentiometer/renesas,x9250.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas X9250 quad potentiometers
+
+maintainers:
+ - Herve Codina <[email protected]>
+
+description:
+ The Renesas X9250 integrates four digitally controlled potentiometers.
+ On each potentiometer, the X9250T has a 100 kOhms total resistance and the
+ X9250U has a 50 kOhms total resistance.
+
+allOf:
+ - $ref: /schemas/spi/spi-peripheral-props.yaml
+ - $ref: /schemas/iio/iio.yaml
+
+properties:
+ compatible:
+ enum:
+ - renesas,x9250t
+ - renesas,x9250u
+
+ reg:
+ description:
+ SPI device address.
+ maxItems: 1
+
+ '#io-channel-cells':
+ const: 1
+
+ spi-max-frequency:
+ maximum: 2000000
+
+required:
+ - compatible
+ - reg
+ - '#io-channel-cells'
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ spi {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ x9250@0 {
+ compatible = "renesas,x9250t";
+ reg = <0>;
+ spi-max-frequency = <2000000>;
+ #io-channel-cells = <1>;
+ };
+ };
--
2.39.2
After contributing the driver, add myself as the maintainer for the
Renesas X9250 IIO driver.
Signed-off-by: Herve Codina <[email protected]>
---
MAINTAINERS | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 8ec7ccba9848..0027af3e14cb 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -17926,6 +17926,13 @@ S: Maintained
F: Documentation/devicetree/bindings/clock/renesas,versaclock7.yaml
F: drivers/clk/clk-versaclock7.c
+RENESAS X9250 DIGITAL POTENTIOMETERS DRIVER
+M: Herve Codina <[email protected]>
+L: [email protected]
+S: Maintained
+F: Documentation/devicetree/bindings/iio/potentiometer/renesas,x9250.yaml
+F: drivers/iio/potentiometer/x9250.c
+
RESET CONTROLLER FRAMEWORK
M: Philipp Zabel <[email protected]>
S: Maintained
--
2.39.2
On 4/20/23 05:13, Herve Codina wrote:
> The Renesas X9250 integrates four digitally controlled potentiometers.
> On each potentiometer, the X9250T has a 100 kOhms total resistance and
> the X9250U has a 50 kOhms total resistance.
>
> Signed-off-by: Herve Codina <[email protected]>
Hi,
Looks perfect! Just one small comment.
> +static int x9250_write8(struct x9250 *x9250, u8 cmd, u8 val)
> +{
> + struct spi_transfer xfer = {
> + .tx_buf = &x9250->spi_tx_buf,
> + .len = 3,
> + };
> + int ret;
> +
> + BUILD_BUG_ON(sizeof(x9250->spi_tx_buf) < 3);
> +
> + mutex_lock(&x9250->lock);
> +
> + x9250->spi_tx_buf[0] = 0x50;
The 0x50 shows up as a magic constant in multiple places, a define for
it would be nice.
> + x9250->spi_tx_buf[1] = cmd;
> + x9250->spi_tx_buf[2] = val;
> +
> + ret = spi_sync_transfer(x9250->spi, &xfer, 1);
> +
> + mutex_unlock(&x9250->lock);
> +
> + return ret;
> +}
On Thu, 20 Apr 2023 06:47:32 -0700
Lars-Peter Clausen <[email protected]> wrote:
> On 4/20/23 05:13, Herve Codina wrote:
> > The Renesas X9250 integrates four digitally controlled potentiometers.
> > On each potentiometer, the X9250T has a 100 kOhms total resistance and
> > the X9250U has a 50 kOhms total resistance.
> >
> > Signed-off-by: Herve Codina <[email protected]>
>
> Hi,
>
> Looks perfect! Just one small comment.
>
> > +static int x9250_write8(struct x9250 *x9250, u8 cmd, u8 val)
> > +{
> > + struct spi_transfer xfer = {
> > + .tx_buf = &x9250->spi_tx_buf,
> > + .len = 3,
> > + };
> > + int ret;
> > +
> > + BUILD_BUG_ON(sizeof(x9250->spi_tx_buf) < 3);
> > +
> > + mutex_lock(&x9250->lock);
> > +
> > + x9250->spi_tx_buf[0] = 0x50;
> The 0x50 shows up as a magic constant in multiple places, a define for
> it would be nice.
Sure, a define will be present in next iteration.
> > + x9250->spi_tx_buf[1] = cmd;
> > + x9250->spi_tx_buf[2] = val;
> > +
> > + ret = spi_sync_transfer(x9250->spi, &xfer, 1);
> > +
> > + mutex_unlock(&x9250->lock);
> > +
> > + return ret;
> > +}
Thanks for the review,
Hervé
--
Hervé Codina, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
On 20/04/2023 14:13, Herve Codina wrote:
> The Renesas X9250 is a quad digitally controlled potentiometers.
>
Thank you for your patch. There is something to discuss/improve.
> +maintainers:
> + - Herve Codina <[email protected]>
> +
> +description:
> + The Renesas X9250 integrates four digitally controlled potentiometers.
> + On each potentiometer, the X9250T has a 100 kOhms total resistance and the
> + X9250U has a 50 kOhms total resistance.
> +
> +allOf:
> + - $ref: /schemas/spi/spi-peripheral-props.yaml
> + - $ref: /schemas/iio/iio.yaml
> +
> +properties:
> + compatible:
> + enum:
> + - renesas,x9250t
> + - renesas,x9250u
> +
> + reg:
> + description:
> + SPI device address.
SPI bus does not have device addresses, AFAIR. Drop description.
> + maxItems: 1
> +
> + '#io-channel-cells':
> + const: 1
> +
> + spi-max-frequency:
> + maximum: 2000000
> +
> +required:
> + - compatible
> + - reg
> + - '#io-channel-cells'
> +
> +unevaluatedProperties: false
> +
> +examples:
> + - |
> + spi {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + x9250@0 {
Node names should be generic.
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
> + compatible = "renesas,x9250t";
> + reg = <0>;
> + spi-max-frequency = <2000000>;
> + #io-channel-cells = <1>;
> + };
> + };
Best regards,
Krzysztof
Hi Krzysztof,
On Fri, 21 Apr 2023 09:32:57 +0200
Krzysztof Kozlowski <[email protected]> wrote:
> On 20/04/2023 14:13, Herve Codina wrote:
> > The Renesas X9250 is a quad digitally controlled potentiometers.
> >
>
> Thank you for your patch. There is something to discuss/improve.
>
> > +maintainers:
> > + - Herve Codina <[email protected]>
> > +
> > +description:
> > + The Renesas X9250 integrates four digitally controlled potentiometers.
> > + On each potentiometer, the X9250T has a 100 kOhms total resistance and the
> > + X9250U has a 50 kOhms total resistance.
> > +
> > +allOf:
> > + - $ref: /schemas/spi/spi-peripheral-props.yaml
> > + - $ref: /schemas/iio/iio.yaml
> > +
> > +properties:
> > + compatible:
> > + enum:
> > + - renesas,x9250t
> > + - renesas,x9250u
> > +
> > + reg:
> > + description:
> > + SPI device address.
>
> SPI bus does not have device addresses, AFAIR. Drop description.
Indeed, SPI has chip-select.
I will drop the description
>
> > + maxItems: 1
> > +
> > + '#io-channel-cells':
> > + const: 1
> > +
> > + spi-max-frequency:
> > + maximum: 2000000
> > +
> > +required:
> > + - compatible
> > + - reg
> > + - '#io-channel-cells'
> > +
> > +unevaluatedProperties: false
> > +
> > +examples:
> > + - |
> > + spi {
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> > + x9250@0 {
>
> Node names should be generic.
> https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
Will be change to potentiometer@0
>
> > + compatible = "renesas,x9250t";
> > + reg = <0>;
> > + spi-max-frequency = <2000000>;
> > + #io-channel-cells = <1>;
> > + };
> > + };
>
> Best regards,
> Krzysztof
>
The modifications will be present on v3 as v2 was already sent.
Thanks for the review,
Hervé