[PATCH v3 08/10] iio: pressure: mprls0025pa refactor

From: Petre Rodan
Date: Fri Dec 29 2023 - 04:26:50 EST


Refactor driver by splitting the code into core and i2c.

Seemingly redundant read/write function parameters are required for
compatibility with the SPI driver.

Co-developed-by: Andreas Klinger <ak@xxxxxxxxxxxxx>
Signed-off-by: Andreas Klinger <ak@xxxxxxxxxxxxx>
Signed-off-by: Petre Rodan <petre.rodan@xxxxxxxxxxxxxxx>
---
v2 -> v3 move '#include <linux/iio/iio.h>' to mprls0025pa.h
fix checkpatch.pl warnings related to mprls0025pa.h

MAINTAINERS | 3 +-
drivers/iio/pressure/Kconfig | 6 +
drivers/iio/pressure/Makefile | 1 +
drivers/iio/pressure/mprls0025pa.c | 185 +++++++------------------
drivers/iio/pressure/mprls0025pa.h | 102 ++++++++++++++
drivers/iio/pressure/mprls0025pa_i2c.c | 98 +++++++++++++
6 files changed, 262 insertions(+), 133 deletions(-)
create mode 100644 drivers/iio/pressure/mprls0025pa.h
create mode 100644 drivers/iio/pressure/mprls0025pa_i2c.c

diff --git a/MAINTAINERS b/MAINTAINERS
index a31b1b20c6f6..77ee0b4d9f73 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9686,10 +9686,11 @@ F: drivers/iio/pressure/hsc030pa*

HONEYWELL MPRLS0025PA PRESSURE SENSOR SERIES IIO DRIVER
M: Andreas Klinger <ak@xxxxxxxxxxxxx>
+M: Petre Rodan <petre.rodan@xxxxxxxxxxxxxxx>
L: linux-iio@xxxxxxxxxxxxxxx
S: Maintained
F: Documentation/devicetree/bindings/iio/pressure/honeywell,mprls0025pa.yaml
-F: drivers/iio/pressure/mprls0025pa.c
+F: drivers/iio/pressure/mprls0025pa*

HOST AP DRIVER
L: linux-wireless@xxxxxxxxxxxxxxx
diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig
index 79adfd059c3a..f03007cfec85 100644
--- a/drivers/iio/pressure/Kconfig
+++ b/drivers/iio/pressure/Kconfig
@@ -182,6 +182,7 @@ config MPL3115
config MPRLS0025PA
tristate "Honeywell MPRLS0025PA (MicroPressure sensors series)"
depends on I2C
+ select MPRLS0025PA_I2C if I2C
select IIO_BUFFER
select IIO_TRIGGERED_BUFFER
help
@@ -192,6 +193,11 @@ config MPRLS0025PA
To compile this driver as a module, choose M here: the module will be
called mprls0025pa.

+config MPRLS0025PA_I2C
+ tristate
+ depends on MPRLS0025PA
+ depends on I2C
+
config MS5611
tristate "Measurement Specialties MS5611 pressure sensor driver"
select IIO_BUFFER
diff --git a/drivers/iio/pressure/Makefile b/drivers/iio/pressure/Makefile
index b0f8b94662f2..7754135e190c 100644
--- a/drivers/iio/pressure/Makefile
+++ b/drivers/iio/pressure/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_MPL115_I2C) += mpl115_i2c.o
obj-$(CONFIG_MPL115_SPI) += mpl115_spi.o
obj-$(CONFIG_MPL3115) += mpl3115.o
obj-$(CONFIG_MPRLS0025PA) += mprls0025pa.o
+obj-$(CONFIG_MPRLS0025PA_I2C) += mprls0025pa_i2c.o
obj-$(CONFIG_MS5611) += ms5611_core.o
obj-$(CONFIG_MS5611_I2C) += ms5611_i2c.o
obj-$(CONFIG_MS5611_SPI) += ms5611_spi.o
diff --git a/drivers/iio/pressure/mprls0025pa.c b/drivers/iio/pressure/mprls0025pa.c
index fef3ca69c4f0..ce20cf362fac 100644
--- a/drivers/iio/pressure/mprls0025pa.c
+++ b/drivers/iio/pressure/mprls0025pa.c
@@ -7,12 +7,11 @@
* Data sheet:
* https://prod-edam.honeywell.com/content/dam/honeywell-edam/sps/siot/en-us/products/sensors/pressure-sensors/board-mount-pressure-sensors/micropressure-mpr-series/documents/sps-siot-mpr-series-datasheet-32332628-ciid-172626.pdf
*
- * 7-bit I2C default slave address: 0x18
*/

-#include <linux/delay.h>
-#include <linux/device.h>
-#include <linux/i2c.h>
+#include <linux/array_size.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
#include <linux/math64.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
@@ -22,7 +21,6 @@
#include <linux/gpio/consumer.h>

#include <linux/iio/buffer.h>
-#include <linux/iio/iio.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>

@@ -30,13 +28,15 @@

#include <asm/unaligned.h>

-/* bits in i2c status byte */
-#define MPR_I2C_POWER BIT(6) /* device is powered */
-#define MPR_I2C_BUSY BIT(5) /* device is busy */
-#define MPR_I2C_MEMORY BIT(2) /* integrity test passed */
-#define MPR_I2C_MATH BIT(0) /* internal math saturation */
+#include "mprls0025pa.h"

-#define MPR_I2C_ERR_FLAG (MPR_I2C_BUSY | MPR_I2C_MEMORY | MPR_I2C_MATH)
+/* bits in status byte */
+#define MPR_ST_POWER BIT(6) /* device is powered */
+#define MPR_ST_BUSY BIT(5) /* device is busy */
+#define MPR_ST_MEMORY BIT(2) /* integrity test passed */
+#define MPR_ST_MATH BIT(0) /* internal math saturation */
+
+#define MPR_ST_ERR_FLAG (MPR_ST_BUSY | MPR_ST_MEMORY | MPR_ST_MATH)

/*
* support _RAW sysfs interface:
@@ -69,12 +69,6 @@
* transfer function B: 2.5% to 22.5% of 2^24
* transfer function C: 20% to 80% of 2^24
*/
-enum mpr_func_id {
- MPR_FUNCTION_A,
- MPR_FUNCTION_B,
- MPR_FUNCTION_C,
-};
-
struct mpr_func_spec {
u32 output_min;
u32 output_max;
@@ -86,45 +80,6 @@ static const struct mpr_func_spec mpr_func_spec[] = {
[MPR_FUNCTION_C] = { .output_min = 3355443, .output_max = 13421773 },
};

-struct mpr_chan {
- s32 pres; /* pressure value */
- s64 ts; /* timestamp */
-};
-
-struct mpr_data {
- struct i2c_client *client;
- struct mutex lock; /*
- * access to device during read
- */
- u32 pmin; /* minimal pressure in pascal */
- u32 pmax; /* maximal pressure in pascal */
- enum mpr_func_id function; /* transfer function */
- u32 outmin; /*
- * minimal numerical range raw
- * value from sensor
- */
- u32 outmax; /*
- * maximal numerical range raw
- * value from sensor
- */
- int scale; /* int part of scale */
- int scale2; /* nano part of scale */
- int offset; /* int part of offset */
- int offset2; /* nano part of offset */
- struct gpio_desc *gpiod_reset; /* reset */
- int irq; /*
- * end of conversion irq;
- * used to distinguish between
- * irq mode and reading in a
- * loop until data is ready
- */
- struct completion completion; /* handshake from irq to read */
- struct mpr_chan chan; /*
- * channel values for buffered
- * mode
- */
-};
-
static const struct iio_chan_spec mpr_channels[] = {
{
.type = IIO_PRESSURE,
@@ -152,11 +107,11 @@ static void mpr_reset(struct mpr_data *data)
}

/**
- * mpr_read_pressure() - Read pressure value from sensor via I2C
+ * mpr_read_pressure() - Read pressure value from sensor
* @data: Pointer to private data struct.
* @press: Output value read from sensor.
*
- * Reading from the sensor by sending and receiving I2C telegrams.
+ * Reading from the sensor by sending and receiving telegrams.
*
* If there is an end of conversion (EOC) interrupt registered the function
* waits for a maximum of one second for the interrupt.
@@ -169,25 +124,17 @@ static void mpr_reset(struct mpr_data *data)
*/
static int mpr_read_pressure(struct mpr_data *data, s32 *press)
{
- struct device *dev = &data->client->dev;
+ struct device *dev = data->dev;
int ret, i;
- u8 wdata[] = {0xAA, 0x00, 0x00};
- s32 status;
int nloops = 10;
- u8 buf[4];

reinit_completion(&data->completion);

- ret = i2c_master_send(data->client, wdata, sizeof(wdata));
+ ret = data->ops->write(data, MPR_CMD_SYNC, MPR_PKT_SYNC_LEN);
if (ret < 0) {
dev_err(dev, "error while writing ret: %d\n", ret);
return ret;
}
- if (ret != sizeof(wdata)) {
- dev_err(dev, "received size doesn't fit - ret: %d / %u\n", ret,
- (u32)sizeof(wdata));
- return -EIO;
- }

if (data->irq > 0) {
ret = wait_for_completion_timeout(&data->completion, HZ);
@@ -205,14 +152,14 @@ static int mpr_read_pressure(struct mpr_data *data, s32 *press)
* quite long
*/
usleep_range(5000, 10000);
- status = i2c_smbus_read_byte(data->client);
- if (status < 0) {
+ ret = data->ops->read(data, MPR_CMD_NOP, 1);
+ if (ret < 0) {
dev_err(dev,
"error while reading, status: %d\n",
- status);
- return status;
+ ret);
+ return ret;
}
- if (!(status & MPR_I2C_ERR_FLAG))
+ if (!(data->buffer[0] & MPR_ST_ERR_FLAG))
break;
}
if (i == nloops) {
@@ -221,29 +168,19 @@ static int mpr_read_pressure(struct mpr_data *data, s32 *press)
}
}

- ret = i2c_master_recv(data->client, buf, sizeof(buf));
- if (ret < 0) {
- dev_err(dev, "error in i2c_master_recv ret: %d\n", ret);
+ ret = data->ops->read(data, MPR_CMD_NOP, MPR_PKT_NOP_LEN);
+ if (ret < 0)
return ret;
- }
- if (ret != sizeof(buf)) {
- dev_err(dev, "received size doesn't fit - ret: %d / %u\n", ret,
- (u32)sizeof(buf));
- return -EIO;
- }

- if (buf[0] & MPR_I2C_ERR_FLAG) {
- /*
- * it should never be the case that status still indicates
- * business
- */
- dev_err(dev, "data still not ready: %08x\n", buf[0]);
+ if (data->buffer[0] & MPR_ST_ERR_FLAG) {
+ dev_err(data->dev,
+ "unexpected status byte %02x\n", data->buffer[0]);
return -ETIMEDOUT;
}

- *press = get_unaligned_be24(&buf[1]);
+ *press = get_unaligned_be24(&data->buffer[1]);

- dev_dbg(dev, "received: %*ph cnt: %d\n", ret, buf, *press);
+ dev_dbg(dev, "received: %*ph cnt: %d\n", ret, data->buffer, *press);

return 0;
}
@@ -315,26 +252,22 @@ static const struct iio_info mpr_info = {
.read_raw = &mpr_read_raw,
};

-static int mpr_probe(struct i2c_client *client)
+int mpr_common_probe(struct device *dev, const struct mpr_ops *ops, int irq)
{
int ret;
struct mpr_data *data;
struct iio_dev *indio_dev;
- struct device *dev = &client->dev;
s64 scale, offset;
u32 func;

- if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_BYTE))
- return dev_err_probe(dev, -EOPNOTSUPP,
- "I2C functionality not supported\n");
-
indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
if (!indio_dev)
- return dev_err_probe(dev, -ENOMEM, "couldn't get iio_dev\n");
+ return -ENOMEM;

data = iio_priv(indio_dev);
- data->client = client;
- data->irq = client->irq;
+ data->dev = dev;
+ data->ops = ops;
+ data->irq = irq;

mutex_init(&data->lock);
init_completion(&data->completion);
@@ -350,16 +283,10 @@ static int mpr_probe(struct i2c_client *client)
return dev_err_probe(dev, ret,
"can't get and enable vdd supply\n");

- ret = device_property_read_u32(dev, "honeywell,pmin-pascal",
- &data->pmin);
+ ret = data->ops->init(data->dev);
if (ret)
- return dev_err_probe(dev, ret,
- "honeywell,pmin-pascal could not be read\n");
- ret = device_property_read_u32(dev, "honeywell,pmax-pascal",
- &data->pmax);
- if (ret)
- return dev_err_probe(dev, ret,
- "honeywell,pmax-pascal could not be read\n");
+ return ret;
+
ret = device_property_read_u32(dev,
"honeywell,transfer-function", &func);
if (ret)
@@ -371,6 +298,21 @@ static int mpr_probe(struct i2c_client *client)
"honeywell,transfer-function %d invalid\n",
data->function);

+ ret = device_property_read_u32(dev, "honeywell,pmin-pascal",
+ &data->pmin);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "honeywell,pmin-pascal could not be read\n");
+ ret = device_property_read_u32(dev, "honeywell,pmax-pascal",
+ &data->pmax);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "honeywell,pmax-pascal could not be read\n");
+
+ if (data->pmin >= data->pmax)
+ return dev_err_probe(dev, -EINVAL,
+ "pressure limits are invalid\n");
+
data->outmin = mpr_func_spec[data->function].output_min;
data->outmax = mpr_func_spec[data->function].output_max;

@@ -389,7 +331,7 @@ static int mpr_probe(struct i2c_client *client)
if (data->irq > 0) {
ret = devm_request_irq(dev, data->irq, mpr_eoc_handler,
IRQF_TRIGGER_RISING,
- client->name,
+ dev_name(dev),
data);
if (ret)
return dev_err_probe(dev, ret,
@@ -417,29 +359,8 @@ static int mpr_probe(struct i2c_client *client)

return 0;
}
-
-static const struct of_device_id mpr_matches[] = {
- { .compatible = "honeywell,mprls0025pa" },
- { }
-};
-MODULE_DEVICE_TABLE(of, mpr_matches);
-
-static const struct i2c_device_id mpr_id[] = {
- { "mprls0025pa" },
- { }
-};
-MODULE_DEVICE_TABLE(i2c, mpr_id);
-
-static struct i2c_driver mpr_driver = {
- .probe = mpr_probe,
- .id_table = mpr_id,
- .driver = {
- .name = "mprls0025pa",
- .of_match_table = mpr_matches,
- },
-};
-module_i2c_driver(mpr_driver);
+EXPORT_SYMBOL_NS(mpr_common_probe, IIO_HONEYWELL_MPRLS0025PA);

MODULE_AUTHOR("Andreas Klinger <ak@xxxxxxxxxxxxx>");
-MODULE_DESCRIPTION("Honeywell MPRLS0025PA I2C driver");
+MODULE_DESCRIPTION("Honeywell MPR pressure sensor core driver");
MODULE_LICENSE("GPL");
diff --git a/drivers/iio/pressure/mprls0025pa.h b/drivers/iio/pressure/mprls0025pa.h
new file mode 100644
index 000000000000..9d5c30afa9d6
--- /dev/null
+++ b/drivers/iio/pressure/mprls0025pa.h
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * MPRLS0025PA - Honeywell MicroPressure pressure sensor series driver
+ *
+ * Copyright (c) Andreas Klinger <ak@xxxxxxxxxxxxx>
+ *
+ * Data sheet:
+ * https://prod-edam.honeywell.com/content/dam/honeywell-edam/sps/siot/en-us/products/sensors/pressure-sensors/board-mount-pressure-sensors/micropressure-mpr-series/documents/sps-siot-mpr-series-datasheet-32332628-ciid-172626.pdf
+ */
+
+#ifndef _MPRLS0025PA_H
+#define _MPRLS0025PA_H
+
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/mutex.h>
+#include <linux/stddef.h>
+#include <linux/types.h>
+
+#include <linux/iio/iio.h>
+
+#define MPR_MEASUREMENT_RD_SIZE 4
+#define MPR_CMD_NOP 0xf0
+#define MPR_CMD_SYNC 0xaa
+#define MPR_PKT_NOP_LEN MPR_MEASUREMENT_RD_SIZE
+#define MPR_PKT_SYNC_LEN 3
+
+struct device;
+
+struct iio_chan_spec;
+struct iio_dev;
+
+struct mpr_data;
+struct mpr_ops;
+
+/**
+ * struct mpr_chan
+ * @pres: pressure value
+ * @ts: timestamp
+ */
+struct mpr_chan {
+ s32 pres;
+ s64 ts;
+};
+
+enum mpr_func_id {
+ MPR_FUNCTION_A,
+ MPR_FUNCTION_B,
+ MPR_FUNCTION_C,
+};
+
+/**
+ * struct mpr_data
+ * @dev: current device structure
+ * @ops: functions that implement the sensor reads/writes, bus init
+ * @lock: access to device during read
+ * @pmin: minimal pressure in pascal
+ * @pmax: maximal pressure in pascal
+ * @function: transfer function
+ * @outmin: minimum raw pressure in counts (based on transfer function)
+ * @outmax: maximum raw pressure in counts (based on transfer function)
+ * @scale: pressure scale
+ * @scale2: pressure scale, decimal number
+ * @offset: pressure offset
+ * @offset2: pressure offset, decimal number
+ * @gpiod_reset: reset
+ * @irq: end of conversion irq. used to distinguish between irq mode and
+ * reading in a loop until data is ready
+ * @completion: handshake from irq to read
+ * @chan: channel values for buffered mode
+ * @buffer: raw conversion data
+ */
+struct mpr_data {
+ struct device *dev;
+ const struct mpr_ops *ops;
+ struct mutex lock;
+ u32 pmin;
+ u32 pmax;
+ enum mpr_func_id function;
+ u32 outmin;
+ u32 outmax;
+ int scale;
+ int scale2;
+ int offset;
+ int offset2;
+ struct gpio_desc *gpiod_reset;
+ int irq;
+ struct completion completion;
+ struct mpr_chan chan;
+ u8 buffer[MPR_MEASUREMENT_RD_SIZE] __aligned(IIO_DMA_MINALIGN);
+};
+
+struct mpr_ops {
+ int (*init)(struct device *dev);
+ int (*read)(struct mpr_data *data, const u8 cmd, const u8 cnt);
+ int (*write)(struct mpr_data *data, const u8 cmd, const u8 cnt);
+};
+
+int mpr_common_probe(struct device *dev, const struct mpr_ops *ops, int irq);
+
+#endif
diff --git a/drivers/iio/pressure/mprls0025pa_i2c.c b/drivers/iio/pressure/mprls0025pa_i2c.c
new file mode 100644
index 000000000000..7e9d1617c9f3
--- /dev/null
+++ b/drivers/iio/pressure/mprls0025pa_i2c.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * MPRLS0025PA - Honeywell MicroPressure pressure sensor series driver
+ *
+ * Copyright (c) Andreas Klinger <ak@xxxxxxxxxxxxx>
+ *
+ * Data sheet:
+ * https://prod-edam.honeywell.com/content/dam/honeywell-edam/sps/siot/en-us/products/sensors/pressure-sensors/board-mount-pressure-sensors/micropressure-mpr-series/documents/sps-siot-mpr-series-datasheet-32332628-ciid-172626.pdf
+ */
+
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+
+#include "mprls0025pa.h"
+
+static int mpr_i2c_init(struct device *unused)
+{
+ return 0;
+}
+
+static int mpr_i2c_read(struct mpr_data *data, const u8 unused, const u8 cnt)
+{
+ int ret;
+ struct i2c_client *client = to_i2c_client(data->dev);
+
+ if (cnt > MPR_MEASUREMENT_RD_SIZE)
+ return -EOVERFLOW;
+
+ memset(data->buffer, 0, MPR_MEASUREMENT_RD_SIZE);
+ ret = i2c_master_recv(client, data->buffer, cnt);
+ if (ret < 0)
+ return ret;
+ else if (ret != cnt)
+ return -EIO;
+
+ return 0;
+}
+
+static int mpr_i2c_write(struct mpr_data *data, const u8 cmd, const u8 unused)
+{
+ int ret;
+ struct i2c_client *client = to_i2c_client(data->dev);
+ u8 wdata[MPR_PKT_SYNC_LEN];
+
+ memset(wdata, 0, sizeof(wdata));
+ wdata[0] = cmd;
+
+ ret = i2c_master_send(client, wdata, MPR_PKT_SYNC_LEN);
+ if (ret < 0)
+ return ret;
+ else if (ret != MPR_PKT_SYNC_LEN)
+ return -EIO;
+
+ return 0;
+}
+
+static const struct mpr_ops mpr_i2c_ops = {
+ .init = mpr_i2c_init,
+ .read = mpr_i2c_read,
+ .write = mpr_i2c_write,
+};
+
+static int mpr_i2c_probe(struct i2c_client *client)
+{
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_BYTE))
+ return -EOPNOTSUPP;
+
+ return mpr_common_probe(&client->dev, &mpr_i2c_ops, client->irq);
+}
+
+static const struct of_device_id mpr_i2c_match[] = {
+ { .compatible = "honeywell,mprls0025pa" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, mpr_i2c_match);
+
+static const struct i2c_device_id mpr_i2c_id[] = {
+ { "mprls0025pa" },
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, mpr_i2c_id);
+
+static struct i2c_driver mpr_i2c_driver = {
+ .probe = mpr_i2c_probe,
+ .id_table = mpr_i2c_id,
+ .driver = {
+ .name = "mprls0025pa",
+ .of_match_table = mpr_i2c_match,
+ },
+};
+module_i2c_driver(mpr_i2c_driver);
+
+MODULE_AUTHOR("Andreas Klinger <ak@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Honeywell MPR pressure sensor i2c driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(IIO_HONEYWELL_MPRLS0025PA);
--
2.41.0