* [PATCH v7 1/2] dt-bindings: iio: adc: add max14001
@ 2023-06-20 13:26 Kim Seer Paller
2023-06-20 13:26 ` [PATCH v7 2/2] iio: adc: max14001: New driver Kim Seer Paller
2023-06-20 13:29 ` [PATCH v7 1/2] dt-bindings: iio: adc: add max14001 Krzysztof Kozlowski
0 siblings, 2 replies; 6+ messages in thread
From: Kim Seer Paller @ 2023-06-20 13:26 UTC (permalink / raw
Cc: jic23, lars, lgirdwood, broonie, Michael.Hennerich,
andy.shevchenko, robh, krzysztof.kozlowski, conor+dt,
kimseer.paller, linux-iio, linux-kernel, devicetree
The MAX14001 is a configurable, isolated 10-bit ADC for multi-range
binary inputs.
Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
---
V6 -> V7: No changes.
V5 -> V6: Removed tags.
V3 -> V5: Added spaces between prefixes in subject. Fixed MAINTAINERS reference.
.../bindings/iio/adc/adi,max14001.yaml | 54 +++++++++++++++++++
MAINTAINERS | 7 +++
2 files changed, 61 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,max14001.yaml
diff --git a/Documentation/devicetree/bindings/iio/adc/adi,max14001.yaml b/Documentation/devicetree/bindings/iio/adc/adi,max14001.yaml
new file mode 100644
index 000000000000..9d03c611fca3
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/adi,max14001.yaml
@@ -0,0 +1,54 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright 2023 Analog Devices Inc.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/adi,max14001.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices MAX14001 ADC
+
+maintainers:
+ - Kim Seer Paller <kimseer.paller@analog.com>
+
+description: |
+ Single channel 10 bit ADC with SPI interface. Datasheet
+ can be found here:
+ https://www.analog.com/media/en/technical-documentation/data-sheets/MAX14001-MAX14002.pdf
+
+properties:
+ compatible:
+ enum:
+ - adi,max14001
+
+ reg:
+ maxItems: 1
+
+ spi-max-frequency:
+ maximum: 5000000
+
+ vref-supply:
+ description: Voltage reference to establish input scaling.
+
+required:
+ - compatible
+ - reg
+
+allOf:
+ - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ spi {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ adc@0 {
+ compatible = "adi,max14001";
+ reg = <0>;
+ spi-max-frequency = <5000000>;
+ vref-supply = <&vref_reg>;
+ };
+ };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index f794002a192e..dcea2c31f920 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12670,6 +12670,13 @@ S: Maintained
F: Documentation/devicetree/bindings/sound/max9860.txt
F: sound/soc/codecs/max9860.*
+MAX14001 IIO ADC DRIVER
+M: Kim Seer Paller <kimseer.paller@analog.com>
+L: linux-iio@vger.kernel.org
+S: Supported
+W: https://ez.analog.com/linux-software-drivers
+F: Documentation/devicetree/bindings/iio/adc/adi,max14001.yaml
+
MAXBOTIX ULTRASONIC RANGER IIO DRIVER
M: Andreas Klinger <ak@it-klinger.de>
L: linux-iio@vger.kernel.org
base-commit: 6f449d52b90fdd927fcf9df0388701de6d5381c6
--
2.34.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v7 2/2] iio: adc: max14001: New driver
2023-06-20 13:26 [PATCH v7 1/2] dt-bindings: iio: adc: add max14001 Kim Seer Paller
@ 2023-06-20 13:26 ` Kim Seer Paller
2023-06-20 15:15 ` Andy Shevchenko
2023-06-20 13:29 ` [PATCH v7 1/2] dt-bindings: iio: adc: add max14001 Krzysztof Kozlowski
1 sibling, 1 reply; 6+ messages in thread
From: Kim Seer Paller @ 2023-06-20 13:26 UTC (permalink / raw
Cc: jic23, lars, lgirdwood, broonie, Michael.Hennerich,
andy.shevchenko, robh, krzysztof.kozlowski, conor+dt,
kimseer.paller, linux-iio, linux-kernel, devicetree
The MAX14001 is configurable, isolated 10-bit ADCs for multi-range
binary inputs.
Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
---
V6 -> V7: Swapped ADC external vref source and regulator_get_voltage
calls. Added forced cast and comment to addressed endian warning.
V5 -> V6: Replaced fixed length assignment with dynamic size
assignment in xfers struct initialization. Removed .channel
assignment in max14001_channels definition.
V4 -> V5: No changes.
V3 -> V4: Removed regmap setup, structures, and include.
MAINTAINERS | 1 +
drivers/iio/adc/Kconfig | 10 ++
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/max14001.c | 340 +++++++++++++++++++++++++++++++++++++
4 files changed, 352 insertions(+)
create mode 100644 drivers/iio/adc/max14001.c
diff --git a/MAINTAINERS b/MAINTAINERS
index dcea2c31f920..b527cf471d7a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12676,6 +12676,7 @@ L: linux-iio@vger.kernel.org
S: Supported
W: https://ez.analog.com/linux-software-drivers
F: Documentation/devicetree/bindings/iio/adc/adi,max14001.yaml
+F: drivers/iio/adc/max14001.c
MAXBOTIX ULTRASONIC RANGER IIO DRIVER
M: Andreas Klinger <ak@it-klinger.de>
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index eb2b09ef5d5b..e599d166e98d 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -706,6 +706,16 @@ config MAX11410
To compile this driver as a module, choose M here: the module will be
called max11410.
+config MAX14001
+ tristate "Analog Devices MAX14001 ADC driver"
+ depends on SPI
+ help
+ Say yes here to build support for Analog Devices MAX14001 Configurable,
+ Isolated 10-bit ADCs for Multi-Range Binary Inputs.
+
+ To compile this driver as a module, choose M here: the module will be
+ called max14001.
+
config MAX1241
tristate "Maxim max1241 ADC driver"
depends on SPI_MASTER
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index e07e4a3e6237..9f8964258f03 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -65,6 +65,7 @@ obj-$(CONFIG_MAX11100) += max11100.o
obj-$(CONFIG_MAX1118) += max1118.o
obj-$(CONFIG_MAX11205) += max11205.o
obj-$(CONFIG_MAX11410) += max11410.o
+obj-$(CONFIG_MAX14001) += max14001.o
obj-$(CONFIG_MAX1241) += max1241.o
obj-$(CONFIG_MAX1363) += max1363.o
obj-$(CONFIG_MAX9611) += max9611.o
diff --git a/drivers/iio/adc/max14001.c b/drivers/iio/adc/max14001.c
new file mode 100644
index 000000000000..b767cf86c5e3
--- /dev/null
+++ b/drivers/iio/adc/max14001.c
@@ -0,0 +1,340 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
+/*
+ * Analog Devices MAX14001 ADC driver
+ *
+ * Copyright 2023 Analog Devices Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitrev.h>
+#include <linux/device.h>
+#include <linux/iio/iio.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/property.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <asm/unaligned.h>
+
+/* MAX14001 Registers Address */
+#define MAX14001_ADC 0x00
+#define MAX14001_FADC 0x01
+#define MAX14001_FLAGS 0x02
+#define MAX14001_FLTEN 0x03
+#define MAX14001_THL 0x04
+#define MAX14001_THU 0x05
+#define MAX14001_INRR 0x06
+#define MAX14001_INRT 0x07
+#define MAX14001_INRP 0x08
+#define MAX14001_CFG 0x09
+#define MAX14001_ENBL 0x0A
+#define MAX14001_ACT 0x0B
+#define MAX14001_WEN 0x0C
+
+#define MAX14001_VERIFICATION_REG(x) ((x) + 0x10)
+
+#define MAX14001_CFG_EXRF BIT(5)
+
+#define MAX14001_ADDR_MASK GENMASK(15, 11)
+#define MAX14001_DATA_MASK GENMASK(9, 0)
+#define MAX14001_FILTER_MASK GENMASK(3, 2)
+
+#define MAX14001_SET_WRITE_BIT BIT(10)
+#define MAX14001_WRITE_WEN 0x294
+
+struct max14001_state {
+ struct spi_device *spi;
+ /*
+ * lock protect against multiple concurrent accesses, RMW sequence, and
+ * SPI transfer
+ */
+ struct mutex lock;
+ int vref_mv;
+ /*
+ * DMA (thus cache coherency maintenance) requires the
+ * transfer buffers to live in their own cache lines.
+ */
+ __be16 spi_tx_buffer __aligned(IIO_DMA_MINALIGN);
+ __be16 spi_rx_buffer;
+};
+
+static int max14001_read(void *context, unsigned int reg_addr, unsigned int *data)
+{
+ struct max14001_state *st = context;
+ int ret;
+
+ struct spi_transfer xfers[] = {
+ {
+ .tx_buf = &st->spi_tx_buffer,
+ .len = sizeof(st->spi_tx_buffer),
+ .cs_change = 1,
+ }, {
+ .rx_buf = &st->spi_rx_buffer,
+ .len = sizeof(st->spi_rx_buffer),
+ },
+ };
+
+ /*
+ * Convert transmit buffer to big-endian format and reverse transmit
+ * buffer to align with the LSB-first input on SDI port.
+ */
+ st->spi_tx_buffer = cpu_to_be16(bitrev16(FIELD_PREP(MAX14001_ADDR_MASK,
+ reg_addr)));
+
+ ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
+ if (ret)
+ return ret;
+
+ /*
+ * Align received data from the receive buffer, reversing and reordering
+ * it to match the expected MSB-first format.
+ */
+ *data = (__force u16)(be16_to_cpu(bitrev16(st->spi_rx_buffer))) &
+ MAX14001_DATA_MASK;
+
+ return 0;
+}
+
+static int max14001_write(void *context, unsigned int reg_addr, unsigned int data)
+{
+ struct max14001_state *st = context;
+
+ /*
+ * Convert transmit buffer to big-endian format and reverse transmit
+ * buffer to align with the LSB-first input on SDI port.
+ */
+ st->spi_tx_buffer = (__force u16)(cpu_to_be16(bitrev16(
+ FIELD_PREP(MAX14001_ADDR_MASK, reg_addr) |
+ FIELD_PREP(MAX14001_SET_WRITE_BIT, 1) |
+ FIELD_PREP(MAX14001_DATA_MASK, data))));
+
+ return spi_write(st->spi, &st->spi_tx_buffer, sizeof(st->spi_tx_buffer));
+}
+
+static int max14001_write_verification_reg(struct max14001_state *st,
+ unsigned int reg_addr)
+{
+ unsigned int reg_data;
+ int ret;
+
+ ret = max14001_read(st, reg_addr, ®_data);
+ if (ret)
+ return ret;
+
+ return max14001_write(st, MAX14001_VERIFICATION_REG(reg_addr), reg_data);
+}
+
+static int max14001_reg_update(struct max14001_state *st,
+ unsigned int reg_addr,
+ unsigned int mask,
+ unsigned int val)
+{
+ int ret;
+ unsigned int reg_data;
+
+ /* Enable SPI Registers Write */
+ ret = max14001_write(st, MAX14001_WEN, MAX14001_WRITE_WEN);
+ if (ret)
+ return ret;
+
+ ret = max14001_read(st, reg_addr, ®_data);
+ if (ret)
+ return ret;
+
+ reg_data = FIELD_PREP(mask, val);
+
+ ret = max14001_write(st, reg_addr, reg_data);
+ if (ret)
+ return ret;
+
+ /* Write Verification Register */
+ ret = max14001_write_verification_reg(st, reg_addr);
+ if (ret)
+ return ret;
+
+ /* Disable SPI Registers Write */
+ return max14001_write(st, MAX14001_WEN, 0);
+}
+
+static int max14001_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct max14001_state *st = iio_priv(indio_dev);
+ unsigned int data;
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&st->lock);
+ ret = max14001_read(st, MAX14001_ADC, &data);
+ mutex_unlock(&st->lock);
+ if (ret < 0)
+ return ret;
+
+ *val = data;
+
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ *val = st->vref_mv;
+ *val2 = 10;
+
+ return IIO_VAL_FRACTIONAL_LOG2;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info max14001_info = {
+ .read_raw = max14001_read_raw,
+};
+
+static const struct iio_chan_spec max14001_channels[] = {
+ {
+ .type = IIO_VOLTAGE,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ }
+};
+
+static void max14001_regulator_disable(void *data)
+{
+ struct regulator *reg = data;
+
+ regulator_disable(reg);
+}
+
+static int max14001_init(struct max14001_state *st)
+{
+ int ret;
+
+ /* Enable SPI Registers Write */
+ ret = max14001_write(st, MAX14001_WEN, MAX14001_WRITE_WEN);
+ if (ret)
+ return ret;
+
+ /*
+ * Reads all registers and writes the values back to their appropriate
+ * verification registers to clear the Memory Validation fault.
+ */
+ ret = max14001_write_verification_reg(st, MAX14001_FLTEN);
+ if (ret)
+ return ret;
+
+ ret = max14001_write_verification_reg(st, MAX14001_THL);
+ if (ret)
+ return ret;
+
+ ret = max14001_write_verification_reg(st, MAX14001_THU);
+ if (ret)
+ return ret;
+
+ ret = max14001_write_verification_reg(st, MAX14001_INRR);
+ if (ret)
+ return ret;
+
+ ret = max14001_write_verification_reg(st, MAX14001_INRT);
+ if (ret)
+ return ret;
+
+ ret = max14001_write_verification_reg(st, MAX14001_INRP);
+ if (ret)
+ return ret;
+
+ ret = max14001_write_verification_reg(st, MAX14001_CFG);
+ if (ret)
+ return ret;
+
+ ret = max14001_write_verification_reg(st, MAX14001_ENBL);
+ if (ret)
+ return ret;
+
+ /* Disable SPI Registers Write */
+ return max14001_write(st, MAX14001_WEN, 0);
+}
+
+static int max14001_probe(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev;
+ struct max14001_state *st;
+ struct regulator *vref;
+ struct device *dev = &spi->dev;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+ st->spi = spi;
+
+ indio_dev->name = "max14001";
+ indio_dev->info = &max14001_info;
+ indio_dev->channels = max14001_channels;
+ indio_dev->num_channels = ARRAY_SIZE(max14001_channels);
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ ret = max14001_init(st);
+ if (ret)
+ return ret;
+
+ vref = devm_regulator_get_optional(dev, "vref");
+ if (IS_ERR(vref)) {
+ if (PTR_ERR(vref) != -ENODEV)
+ return dev_err_probe(dev, PTR_ERR(vref),
+ "Failed to get vref regulator");
+
+ /* internal reference */
+ st->vref_mv = 1250;
+ } else {
+ ret = regulator_enable(vref);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to enable vref regulators\n");
+
+ ret = devm_add_action_or_reset(dev, max14001_regulator_disable,
+ vref);
+ if (ret)
+ return ret;
+
+ ret = regulator_get_voltage(vref);
+ if (ret < 0)
+ return dev_err_probe(dev, ret,
+ "Failed to get vref\n");
+
+ st->vref_mv = ret / 1000;
+
+ /* select external voltage reference source for the ADC */
+ ret = max14001_reg_update(st, MAX14001_CFG,
+ MAX14001_CFG_EXRF, 1);
+ if (ret < 0)
+ return ret;
+ }
+
+ mutex_init(&st->lock);
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct of_device_id max14001_of_match[] = {
+ { .compatible = "adi,max14001" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, max14001_of_match);
+
+static struct spi_driver max14001_driver = {
+ .driver = {
+ .name = "max14001",
+ .of_match_table = max14001_of_match,
+ },
+ .probe = max14001_probe,
+};
+module_spi_driver(max14001_driver);
+
+MODULE_AUTHOR("Kim Seer Paller");
+MODULE_DESCRIPTION("MAX14001 ADC driver");
+MODULE_LICENSE("GPL");
--
2.34.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v7 1/2] dt-bindings: iio: adc: add max14001
2023-06-20 13:26 [PATCH v7 1/2] dt-bindings: iio: adc: add max14001 Kim Seer Paller
2023-06-20 13:26 ` [PATCH v7 2/2] iio: adc: max14001: New driver Kim Seer Paller
@ 2023-06-20 13:29 ` Krzysztof Kozlowski
1 sibling, 0 replies; 6+ messages in thread
From: Krzysztof Kozlowski @ 2023-06-20 13:29 UTC (permalink / raw
To: Kim Seer Paller
Cc: jic23, lars, lgirdwood, broonie, Michael.Hennerich,
andy.shevchenko, robh, conor+dt, linux-iio, linux-kernel,
devicetree
On 20/06/2023 15:26, Kim Seer Paller wrote:
> The MAX14001 is a configurable, isolated 10-bit ADC for multi-range
> binary inputs.
>
> Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
> ---
> V6 -> V7: No changes.
This is a friendly reminder during the review process.
It looks like you received a tag and forgot to add it.
If you do not know the process, here is a short explanation:
Please add Acked-by/Reviewed-by/Tested-by tags when posting new
versions. However, there's no need to repost patches *only* to add the
tags. The upstream maintainer will do that for acks received on the
version they apply.
https://elixir.bootlin.com/linux/v5.17/source/Documentation/process/submitting-patches.rst#L540
If a tag was not added on purpose, please state why and what changed.\
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v7 2/2] iio: adc: max14001: New driver
2023-06-20 13:26 ` [PATCH v7 2/2] iio: adc: max14001: New driver Kim Seer Paller
@ 2023-06-20 15:15 ` Andy Shevchenko
2023-06-21 0:38 ` Paller, Kim Seer
0 siblings, 1 reply; 6+ messages in thread
From: Andy Shevchenko @ 2023-06-20 15:15 UTC (permalink / raw
To: Kim Seer Paller
Cc: jic23, lars, lgirdwood, broonie, Michael.Hennerich, robh,
krzysztof.kozlowski, conor+dt, linux-iio, linux-kernel,
devicetree
On Tue, Jun 20, 2023 at 4:27 PM Kim Seer Paller
<kimseer.paller@analog.com> wrote:
>
> The MAX14001 is configurable, isolated 10-bit ADCs for multi-range
> binary inputs.
...
> + /*
> + * Align received data from the receive buffer, reversing and reordering
> + * it to match the expected MSB-first format.
> + */
> + *data = (__force u16)(be16_to_cpu(bitrev16(st->spi_rx_buffer))) &
> + MAX14001_DATA_MASK;
Using __force in the C files is somehow stinky.
...
> + /*
> + * Convert transmit buffer to big-endian format and reverse transmit
> + * buffer to align with the LSB-first input on SDI port.
> + */
> + st->spi_tx_buffer = (__force u16)(cpu_to_be16(bitrev16(
You have a different type of spi_tx_buffer than u16, don't you?
> + FIELD_PREP(MAX14001_ADDR_MASK, reg_addr) |
> + FIELD_PREP(MAX14001_SET_WRITE_BIT, 1) |
> + FIELD_PREP(MAX14001_DATA_MASK, data))));
...
> + vref = devm_regulator_get_optional(dev, "vref");
> + if (IS_ERR(vref)) {
> + if (PTR_ERR(vref) != -ENODEV)
> + return dev_err_probe(dev, PTR_ERR(vref),
> + "Failed to get vref regulator");
> +
> + /* internal reference */
> + st->vref_mv = 1250;
> + } else {
> + ret = regulator_enable(vref);
> + if (ret)
> + return dev_err_probe(dev, ret,
> + "Failed to enable vref regulators\n");
> +
> + ret = devm_add_action_or_reset(dev, max14001_regulator_disable,
> + vref);
> + if (ret)
> + return ret;
> +
> + ret = regulator_get_voltage(vref);
> + if (ret < 0)
> + return dev_err_probe(dev, ret,
> + "Failed to get vref\n");
> +
> + st->vref_mv = ret / 1000;
> +
> + /* select external voltage reference source for the ADC */
> + ret = max14001_reg_update(st, MAX14001_CFG,
> + MAX14001_CFG_EXRF, 1);
> + if (ret < 0)
> + return ret;
> + }
Now, looking at this code I'm wondering if we may have something like
devm_regulator_get_enable_and_voltage_optional()
But it's another story.
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: [PATCH v7 2/2] iio: adc: max14001: New driver
2023-06-20 15:15 ` Andy Shevchenko
@ 2023-06-21 0:38 ` Paller, Kim Seer
2023-06-21 8:21 ` Andy Shevchenko
0 siblings, 1 reply; 6+ messages in thread
From: Paller, Kim Seer @ 2023-06-21 0:38 UTC (permalink / raw
To: Andy Shevchenko
Cc: jic23@kernel.org, lars@metafoo.de, lgirdwood@gmail.com,
broonie@kernel.org, Hennerich, Michael, robh@kernel.org,
krzysztof.kozlowski@linaro.org, conor+dt@kernel.org,
linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org,
devicetree@vger.kernel.org
> -----Original Message-----
> From: Andy Shevchenko <andy.shevchenko@gmail.com>
> Sent: Tuesday, June 20, 2023 11:15 PM
> To: Paller, Kim Seer <KimSeer.Paller@analog.com>
> Cc: jic23@kernel.org; lars@metafoo.de; lgirdwood@gmail.com;
> broonie@kernel.org; Hennerich, Michael <Michael.Hennerich@analog.com>;
> robh@kernel.org; krzysztof.kozlowski@linaro.org; conor+dt@kernel.org; linux-
> iio@vger.kernel.org; linux-kernel@vger.kernel.org; devicetree@vger.kernel.org
> Subject: Re: [PATCH v7 2/2] iio: adc: max14001: New driver
>
> [External]
>
> On Tue, Jun 20, 2023 at 4:27 PM Kim Seer Paller
> <kimseer.paller@analog.com> wrote:
> >
> > The MAX14001 is configurable, isolated 10-bit ADCs for multi-range
> > binary inputs.
>
> ...
>
> > + /*
> > + * Align received data from the receive buffer, reversing and reordering
> > + * it to match the expected MSB-first format.
> > + */
> > + *data = (__force u16)(be16_to_cpu(bitrev16(st->spi_rx_buffer))) &
> > + MAX14001_DATA_MASK;
>
> Using __force in the C files is somehow stinky.
>
> ...
>
> > + /*
> > + * Convert transmit buffer to big-endian format and reverse transmit
> > + * buffer to align with the LSB-first input on SDI port.
> > + */
> > + st->spi_tx_buffer = (__force u16)(cpu_to_be16(bitrev16(
>
> You have a different type of spi_tx_buffer than u16, don't you?
I have the same type of spi_tx_buffer as u16.
Other than using force cast, is there any way to resolve the endian warning? I have
actually swapped the order of bitrev16() and cpu_to_be16/be16_to_cpu() functions.
I have tested and they also work fine.
Best regards,
Kim Seer Paller
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v7 2/2] iio: adc: max14001: New driver
2023-06-21 0:38 ` Paller, Kim Seer
@ 2023-06-21 8:21 ` Andy Shevchenko
0 siblings, 0 replies; 6+ messages in thread
From: Andy Shevchenko @ 2023-06-21 8:21 UTC (permalink / raw
To: Paller, Kim Seer
Cc: jic23@kernel.org, lars@metafoo.de, lgirdwood@gmail.com,
broonie@kernel.org, Hennerich, Michael, robh@kernel.org,
krzysztof.kozlowski@linaro.org, conor+dt@kernel.org,
linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org,
devicetree@vger.kernel.org
On Wed, Jun 21, 2023 at 3:38 AM Paller, Kim Seer
<KimSeer.Paller@analog.com> wrote:
> > From: Andy Shevchenko <andy.shevchenko@gmail.com>
> > Sent: Tuesday, June 20, 2023 11:15 PM
> > On Tue, Jun 20, 2023 at 4:27 PM Kim Seer Paller
> > <kimseer.paller@analog.com> wrote:
...
> > > + /*
> > > + * Align received data from the receive buffer, reversing and reordering
> > > + * it to match the expected MSB-first format.
> > > + */
> > > + *data = (__force u16)(be16_to_cpu(bitrev16(st->spi_rx_buffer))) &
> > > + MAX14001_DATA_MASK;
> >
> > Using __force in the C files is somehow stinky.
...
> > > + /*
> > > + * Convert transmit buffer to big-endian format and reverse transmit
> > > + * buffer to align with the LSB-first input on SDI port.
> > > + */
> > > + st->spi_tx_buffer = (__force u16)(cpu_to_be16(bitrev16(
> >
> > You have a different type of spi_tx_buffer than u16, don't you?
>
> I have the same type of spi_tx_buffer as u16.
And you should have __be16.
> Other than using force cast, is there any way to resolve the endian warning? I have
> actually swapped the order of bitrev16() and cpu_to_be16/be16_to_cpu() functions.
> I have tested and they also work fine.
You really have to get it correct on both LE and BE architectures.
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2023-06-21 8:22 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-06-20 13:26 [PATCH v7 1/2] dt-bindings: iio: adc: add max14001 Kim Seer Paller
2023-06-20 13:26 ` [PATCH v7 2/2] iio: adc: max14001: New driver Kim Seer Paller
2023-06-20 15:15 ` Andy Shevchenko
2023-06-21 0:38 ` Paller, Kim Seer
2023-06-21 8:21 ` Andy Shevchenko
2023-06-20 13:29 ` [PATCH v7 1/2] dt-bindings: iio: adc: add max14001 Krzysztof Kozlowski
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