[PATCH 1/3] iio: pressure: Add driver for DLH pressure sensors

tomislav.denis
2019-11-14T10:30:42Z

All Sensors DLH is series of low voltage digital pressure sensors.
Additionally to pressure value sensors deliver a temperature value.
Sensors can be accessed over I2C and SPI, this driver supports
only I2C access.

Signed-off-by: Tomislav Denis <tomislav.denis@avl.com>
---
MAINTAINERS | 7 +
drivers/iio/pressure/Kconfig | 12 ++
drivers/iio/pressure/Makefile | 1 +
drivers/iio/pressure/dlh-i2c.c | 322 +++++++++++++++++++++++++++++++++++++++++
4 files changed, 342 insertions(+)
create mode 100644 drivers/iio/pressure/dlh-i2c.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 8323258..2a08923 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -668,6 +668,13 @@ S: Maintained
F: Documentation/i2c/busses/i2c-ali1563.rst
F: drivers/i2c/busses/i2c-ali1563.c

+ALL SENSORS DLH SERIES PRESSURE SENSORS DRIVER
+M: Tomislav Denis <tomislav.denis@avl.com>
+W: http://www.allsensors.com/cad/DS-0355_Rev_B.PDF
+S: Maintained
+L: linux-iio@vger.kernel.org
+F: drivers/iio/pressure/dlh-i2c.c
+
ALLEGRO DVT VIDEO IP CORE DRIVER
M: Michael Tretter <m.tretter@pengutronix.de>
R: Pengutronix Kernel Team <kernel@pengutronix.de>
diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig
index ba420e4..504de3e 100644
--- a/drivers/iio/pressure/Kconfig
+++ b/drivers/iio/pressure/Kconfig
@@ -53,6 +53,18 @@ config IIO_CROS_EC_BARO
To compile this driver as a module, choose M here: the module
will be called cros_ec_baro.

+config DLH_I2C
+ tristate "All Sensors DLH series low voltage digital pressure sensors"
+ depends on I2C
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
+ help
+ Say yes here to build support for the All Sensors DLH series
+ pressure sensors driver.
+
+ To compile this driver as a module, choose M here: the module
+ will be called dlh-i2c.
+
config DPS310
tristate "Infineon DPS310 pressure and temperature sensor"
depends on I2C
diff --git a/drivers/iio/pressure/Makefile b/drivers/iio/pressure/Makefile
index d8f5ace..1851a36 100644
--- a/drivers/iio/pressure/Makefile
+++ b/drivers/iio/pressure/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_BMP280) += bmp280.o
bmp280-objs := bmp280-core.o bmp280-regmap.o
obj-$(CONFIG_BMP280_I2C) += bmp280-i2c.o
obj-$(CONFIG_BMP280_SPI) += bmp280-spi.o
+obj-$(CONFIG_DLH_I2C) += dlh-i2c.o
obj-$(CONFIG_DPS310) += dps310.o
obj-$(CONFIG_IIO_CROS_EC_BARO) += cros_ec_baro.o
obj-$(CONFIG_HID_SENSOR_PRESS) += hid-sensor-press.o
diff --git a/drivers/iio/pressure/dlh-i2c.c b/drivers/iio/pressure/dlh-i2c.c
new file mode 100644
index 0000000..4ef13c2
--- /dev/null
+++ b/drivers/iio/pressure/dlh-i2c.c
@@ -0,0 +1,322 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * All Sensors DLH series low voltage digital pressure sensors
+ *
+ * Copyright (c) 2019 AVL DiTEST GmbH
+ * Tomislav Denis <tomislav.denis@avl.com>
+ *
+ * Datasheet: http://www.allsensors.com/cad/DS-0355_Rev_B.PDF
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+/* Commands */
+#define DLH_START_SINGLE 0xAA
+
+/* Status bits */
+#define DLH_STATUS_OK 0x40
+
+/* DLH data format */
+#define DLH_NUM_READ_BYTES 7
+#define DLH_NUM_DATA_BYTES 3
+#define DLH_NUM_PR_BITS 24
+#define DLH_NUM_TEMP_BITS 24
+
+/* DLH timings */
+#define DLH_SINGLE_DUT_MS 5
+
+enum dhl_ids {
+ dlhl60d,
+ dlhl60g,
+};
+
+struct dlh_info {
+ u8 osdig; /* digital offset factor */
+ unsigned int fss; /* full scale span (inch H2O) */
+};
+
+struct dlh_state {
+ struct i2c_client *client;
+ struct dlh_info info;
+ u8 rx_buf[DLH_NUM_READ_BYTES] ____cacheline_aligned;
+};
+
+static struct dlh_info dlh_info_tbl[] = {
+ [dlhl60d] = {
+ .osdig = 2,
+ .fss = 120,
+ },
+ [dlhl60g] = {
+ .osdig = 10,
+ .fss = 60,
+ },
+};
+
+static int dlh_i2c_read_direct(struct dlh_state *st,
+ unsigned int *pressure, unsigned int *temperature)
+{
+ int ret;
+
+ ret = i2c_smbus_write_byte(st->client, DLH_START_SINGLE);
+ if (ret) {
+ dev_err(&st->client->dev,
+ "%s: I2C write byte failed\n", __func__);
+ return ret;
+ }
+
+ mdelay(DLH_SINGLE_DUT_MS);
+
+ ret = i2c_master_recv(st->client, st->rx_buf, DLH_NUM_READ_BYTES);
+ if (ret < 0) {
+ dev_err(&st->client->dev,
+ "%s: I2C read block failed\n", __func__);
+ return ret;
+ }
+
+ if (st->rx_buf[0] != DLH_STATUS_OK) {
+ dev_err(&st->client->dev,
+ "%s: invalid status 0x%02x\n", __func__, st->rx_buf[0]);
+ return -EBUSY;
+ }
+
+ *pressure = be32_to_cpup((u32 *)&st->rx_buf[1]) >> 8;
+ *temperature = be32_to_cpup((u32 *)&st->rx_buf[3]) &
+ GENMASK(DLH_NUM_TEMP_BITS - 1, 0);
+
+ return 0;
+}
+
+static int dlh_i2c_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *channel, int *value,
+ int *value2, long mask)
+{
+ struct dlh_state *st = iio_priv(indio_dev);
+ unsigned int pressure, temperature;
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ if (iio_buffer_enabled(indio_dev))
+ return -EBUSY;
+
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ ret = dlh_i2c_read_direct(st, &pressure, &temperature);
+ iio_device_release_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ switch (channel->type) {
+ case IIO_PRESSURE: /* inch H2O */
+ *value = pressure;
+ return IIO_VAL_INT;
+
+ case IIO_TEMP: /* degrees Celsius */
+ *value = temperature;
+ return IIO_VAL_INT;
+
+ default:
+ return -EINVAL;
+ }
+ case IIO_CHAN_INFO_SCALE:
+ switch (channel->type) {
+ case IIO_PRESSURE:
+ *value = 125 * st->info.fss;
+ *value2 = 100 * (1 << DLH_NUM_PR_BITS);
+ return IIO_VAL_FRACTIONAL;
+
+ case IIO_TEMP:
+ *value = 125;
+ *value2 = DLH_NUM_TEMP_BITS;
+ return IIO_VAL_FRACTIONAL_LOG2;
+
+ default:
+ return -EINVAL;
+ }
+ case IIO_CHAN_INFO_OFFSET:
+ switch (channel->type) {
+ case IIO_PRESSURE:
+ *value = -125 * st->info.fss;
+ *value2 = 100 * st->info.osdig;
+ return IIO_VAL_FRACTIONAL;
+
+ case IIO_TEMP:
+ *value = -40;
+ return IIO_VAL_INT;
+
+ default:
+ return -EINVAL;
+ }
+ }
+
+ return -EINVAL;
+}
+
+static const struct iio_info dlh_i2c_info = {
+ .read_raw = dlh_i2c_read_raw,
+};
+
+static const struct iio_chan_spec dlh_i2c_channels[] = {
+ {
+ .type = IIO_PRESSURE,
+ .indexed = 1,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .info_mask_shared_by_type =
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_OFFSET),
+ .scan_index = 0,
+ .scan_type = {
+ .sign = 'u',
+ .realbits = DLH_NUM_PR_BITS,
+ .storagebits = 32,
+ .shift = 8,
+ .endianness = IIO_BE,
+ },
+ }, {
+ .type = IIO_TEMP,
+ .indexed = 1,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .info_mask_shared_by_type =
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_OFFSET),
+ .scan_index = 1,
+ .scan_type = {
+ .sign = 'u',
+ .realbits = DLH_NUM_TEMP_BITS,
+ .storagebits = 32,
+ .shift = 8,
+ .endianness = IIO_BE,
+ },
+ }
+};
+
+static irqreturn_t dlh_i2c_trigger_handler(int irq, void *private)
+{
+ struct iio_poll_func *pf = (struct iio_poll_func *)private;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct dlh_state *st = iio_priv(indio_dev);
+ int ret;
+ unsigned int chn, i = 0;
+ __be32 tmp_buf[2];
+
+ ret = i2c_master_recv(st->client, st->rx_buf, DLH_NUM_READ_BYTES);
+ if (ret < 0) {
+ dev_err(&st->client->dev,
+ "%s: I2C read block failed\n", __func__);
+ goto out;
+ }
+
+ if (st->rx_buf[0] != DLH_STATUS_OK) {
+ dev_err(&st->client->dev,
+ "%s: invalid status 0x%02x\n", __func__, st->rx_buf[0]);
+ goto out;
+ }
+
+ ret = i2c_smbus_write_byte(st->client, DLH_START_SINGLE);
+ if (ret) {
+ dev_err(&st->client->dev,
+ "%s: I2C write byte failed\n", __func__);
+ goto out;
+ }
+
+ for_each_set_bit(chn, indio_dev->active_scan_mask,
+ indio_dev->masklength) {
+ memcpy(tmp_buf + i,
+ &st->rx_buf[1] + chn * DLH_NUM_DATA_BYTES,
+ DLH_NUM_DATA_BYTES);
+ i++;
+ }
+
+ iio_push_to_buffers(indio_dev, tmp_buf);
+
+out:
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
+static int dlh_i2c_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct dlh_state *st;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_I2C | I2C_FUNC_SMBUS_WRITE_BYTE)) {
+ dev_err(&client->dev,
+ "adapter doesn't support required i2c functionality\n");
+ return -EOPNOTSUPP;
+ }
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
+ if (!indio_dev) {
+ dev_err(&client->dev, "failed to allocate iio device\n");
+ return -ENOMEM;
+ }
+
+ i2c_set_clientdata(client, indio_dev);
+
+ st = iio_priv(indio_dev);
+ st->info = dlh_info_tbl[id->driver_data];
+ st->client = client;
+
+ indio_dev->name = id->name;
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->dev.of_node = client->dev.of_node;
+ indio_dev->info = &dlh_i2c_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = dlh_i2c_channels;
+ indio_dev->num_channels = ARRAY_SIZE(dlh_i2c_channels);
+
+ ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev,
+ &iio_pollfunc_store_time, &dlh_i2c_trigger_handler, NULL);
+ if (ret) {
+ dev_err(&client->dev, "failed to setup iio buffer\n");
+ return ret;
+ }
+
+ ret = devm_iio_device_register(&client->dev, indio_dev);
+ if (ret) {
+ dev_err(&client->dev, "failed to register iio device\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct of_device_id dlh_i2c_of_match[] = {
+ { .compatible = "asc,dlhl60d" },
+ { .compatible = "asc,dlhl60g" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, dlh_i2c_of_match);
+
+static const struct i2c_device_id dlh_i2c_id[] = {
+ { "dlhl60d", dlhl60d },
+ { "dlhl60g", dlhl60g },
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, dlh_i2c_id);
+
+static struct i2c_driver dlh_i2c_driver = {
+ .driver = {
+ .name = "dlh_i2c",
+ .of_match_table = dlh_i2c_of_match,
+ },
+ .probe = dlh_i2c_probe,
+ .id_table = dlh_i2c_id,
+};
+module_i2c_driver(dlh_i2c_driver);
+
+MODULE_AUTHOR("Tomislav Denis <tomislav.denis@avl.com>");
+MODULE_DESCRIPTION("Driver for All Sensors DLH series pressure sensors");
+MODULE_LICENSE("GPL v2");
--
2.7.4