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SubjectRe: [PATCH 2/2] iio: add Bosch BMA180 acceleration sensor driver

kicking out drivers fast :)
few comments below; the driver exposes only minimal iio features and
integrates input subsystem, this doesn't seem right

p.

> diff --git a/Documentation/devicetree/bindings/iio/accel/bma180.txt b/Documentation/devicetree/bindings/iio/accel/bma180.txt
> new file mode 100644
> index 0000000..7c13c84
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/accel/bma180.txt
> @@ -0,0 +1,53 @@
> +* Bosch BMA180 triaxial acceleration sensor
> +
> +http://omapworld.com/BMA180_111_1002839.pdf
> +
> +Required properties:
> +
> + - compatible : should be "bosch,bma180"
> + - reg : the I2C address of the sensor
> +
> +Optional properties:
> +
> + - interrupt-parent : should be the phandle for the interrupt controller
> +
> + - interrupts : interrupt mapping for GPIO IRQ, it shuld by configured with
> + flags IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING
> +
> + - range : select the full scale acceleration range
> + 0 : -1g..+1g
> + 1 : -1.5g..+1.5g
> + 2 : -2g..+2g
> + 3 : -3g..+3g
> + 4 : -4g..+4g
> + 5 : -8g..+8g
> + 6 : -16g..+16g
> +
> + - bw : select bandwidth bandwidth
> + 0 : 10Hz
> + 1 : 20Hz
> + 2 : 40Hz
> + 3 : 75Hz
> + 4 : 150Hz
> + 5 : 300Hz
> + Don't use bandwidth frequency more than 300Hz couse it

because

> + influences the frequency of generating new data interrupts
> + and i2c reading phase can be longer than pheriod of interrupt

period

> + generation.
> +
> + - mode_config : 0 - select low noise mode, 1 - select low power mode
> +
> + - fuzz : specifies fuzz value that is used to filter noise from the event stream
> +
> +Example:
> +
> +bma180@40 {
> + compatible = "bosch,bma180";
> + reg = <0x40>;
> + interrupt-parent = <&gpio6>;
> + interrupts = <18 (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING)>;
> + range = <2>;
> + bw = <0>;
> + mode_config = <1>;
> + fuzz = <555>;
> +};
> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
> index 719d83f..61fd29f 100644
> --- a/drivers/iio/accel/Kconfig
> +++ b/drivers/iio/accel/Kconfig
> @@ -3,6 +3,16 @@
> #
> menu "Accelerometers"
>
> +config BMA180
> + tristate "Bosch BMA180 3-Axis Accelerometer Driver"
> + depends on I2C
> + help
> + Say Y here if you want to build a driver for the Bosch BMA180
> + triaxial acceleration sensor.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called bma180.
> +
> config HID_SENSOR_ACCEL_3D
> depends on HID_SENSOR_HUB
> select IIO_BUFFER
> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
> index 87d8fa2..31a36fa 100644
> --- a/drivers/iio/accel/Makefile
> +++ b/drivers/iio/accel/Makefile
> @@ -12,3 +12,5 @@ obj-$(CONFIG_IIO_ST_ACCEL_I2C_3AXIS) += st_accel_i2c.o
> obj-$(CONFIG_IIO_ST_ACCEL_SPI_3AXIS) += st_accel_spi.o
>
> obj-$(CONFIG_KXSD9) += kxsd9.o
> +
> +obj-$(CONFIG_BMA180) += bma180.o

alphabetic order

> diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c
> new file mode 100644
> index 0000000..9f5341f
> --- /dev/null
> +++ b/drivers/iio/accel/bma180.c
> @@ -0,0 +1,462 @@
> +/*
> + * bma180.c - IIO driver for Bosch BMA180 triaxial acceleration sensor
> + *
> + * Copyright 2013 Oleksandr Kravchenko <x0199363@ti.com>
> + *
> + * This file is subject to the terms and conditions of version 2 of
> + * the GNU General Public License. See the file COPYING in the main
> + * directory of this archive for more details.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/delay.h>
> +#include <linux/input.h>
> +#include <linux/of.h>
> +#include <linux/bitops.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/iio/events.h>
> +
> +#define BMA180_DRV_NAME "bma180"
> +#define BMA180_IRQ_NAME "bma180_event"
> +
> +/* Register set */
> +#define BMA180_CHIP_ID 0x00 /* Need to distinguish BMA180 from other */
> +#define BMA180_ACC_X_LSB 0x02 /* First of 6 registers of accel data */
> +#define BMA180_CTRL_REG0 0x0d
> +#define BMA180_RESET 0x10
> +#define BMA180_BW_TCS 0x20
> +#define BMA180_CTRL_REG3 0x21
> +#define BMA180_TCO_Z 0x30
> +#define BMA180_OFFSET_LSB1 0x35
> +
> +/* Control bits */
> +#define BMA180_SLEEP BIT(1) /* 1 - chip will sleep */
> +#define BMA180_DIS_WAKE_UP BIT(0) /* Disable wake up mode */
> +#define BMA180_EE_W BIT(4) /* Unlock writing to addr. from 0x20 */
> +#define BMA180_NEW_DATA_INT BIT(1) /* Intr every new accel data is ready */
> +#define BMA180_SMP_SKIP BIT(0) /* Sample skipping mode */

maybe say which bits belong to which CTRL reg?

> +
> +/* Bit masks fo registerts bit fields */

typos: fo, registerts

> +#define BMA180_RANGE 0x0e /* Range of accel measurment */
> +#define BMA180_BW 0xf0 /* Accel measurmend bandwidth */

typo: measurmend

> +#define BMA180_MODE_CONFIG 0x03 /* Config operation modes */
> +
> +/* We have write this value in reset register to do soft reset */

have 'to' write

> +#define BMA180_RESET_VAL 0xb6
> +
> +/* Chip operation modes */
> +#define BMA180_LOW_NOISE 0x00
> +#define BMA180_LOW_POWER 0x03
> +
> +struct bma180_data {
> + struct i2c_client *client;
> + struct input_dev *input_dev;
> + struct mutex mutex;
> + int sleep_state;
> + int range;
> + int bw;
> + int mode;
> + int fuzz;
> + int acc_reg[3];
> +};
> +
> +enum bma180_axis {
> + AXIS_X,
> + AXIS_Y,
> + AXIS_Z,
> +};
> +
> +struct bma180_range {
> + int g_range;
> + int ratio;
> +};
> +
> +static struct bma180_range bma180_range_table[7] = {
> + { 1000, 130 },
> + { 1500, 190 },
> + { 2000, 250 },
> + { 3000, 380 },
> + { 4000, 500 },
> + { 8000, 990 },
> + { 16000, 1980 },
> +};
> +
> +static int bma180_get_acc_reg(struct bma180_data *data, enum bma180_axis axis)
> +{
> + u8 reg = BMA180_ACC_X_LSB + axis * 2;
> + int ret;
> +
> + if (data->sleep_state)
> + return -EBUSY;
> +
> + ret = i2c_smbus_read_word_data(data->client, reg);
> + if (ret < 0)
> + dev_err(&data->client->dev,
> + "failed to read accel_%c registers\n", 'x' + axis);

just one register, not registers?

> +
> + return ret;
> +}
> +
> +static int bma180_set_bits(struct bma180_data *data, u8 reg, u8 mask, u8 val)
> +{
> + int ret = i2c_smbus_read_byte_data(data->client, reg);
> + u8 reg_val = (ret & ~mask) | (val << (ffs(mask) - 1));
> +
> + if (ret < 0)
> + return ret;
> +
> + return i2c_smbus_write_byte_data(data->client, reg, reg_val);
> +}
> +
> +static int bma180_set_new_data_intr_state(struct bma180_data *data, int state)
> +{
> + u8 reg_val = state ? BMA180_NEW_DATA_INT : 0x00;
> + int ret = i2c_smbus_write_byte_data(data->client, BMA180_CTRL_REG3,
> + reg_val);
> +
> + if (ret)
> + dev_err(&data->client->dev,
> + "failed to set new data interrupt state %d\n", state);
> +
> + return ret;
> +}
> +
> +static int bma180_set_sleep_state(struct bma180_data *data, int state)
> +{
> + int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_SLEEP, state);
> +
> + if (ret) {
> + dev_err(&data->client->dev,
> + "failed to set sleep state %d\n", state);
> + return ret;
> + }
> + data->sleep_state = state;
> +
> + return 0;
> +}
> +
> +static int bma180_set_ee_writing_state(struct bma180_data *data, int state)
> +{
> + int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_EE_W, state);
> +
> + if (ret)
> + dev_err(&data->client->dev,
> + "failed to set ee writing state %d\n", state);
> +
> + return ret;
> +}
> +
> +static int bma180_soft_reset(struct bma180_data *data)
> +{
> + int ret = i2c_smbus_write_byte_data(data->client,
> + BMA180_RESET, BMA180_RESET_VAL);
> +
> + if (ret)
> + dev_err(&data->client->dev, "failed to reset the chip\n");
> +
> + return ret;
> +}
> +
> +static int bma180_chip_init(struct bma180_data *data)
> +{
> + /* Try to read chip_id register. It must return 0x03. */
> + int ret = i2c_smbus_read_byte_data(data->client, BMA180_CHIP_ID);
> +
> + if (ret < 0)
> + goto err;
> + if (ret != 0x03) {
> + ret = -ENODEV;
> + goto err;
> + }
> +
> + ret = bma180_soft_reset(data);
> + if (ret)
> + goto err;
> + /*
> + * No serial transaction should occur within minimum 10 μs
> + * after soft_reset command
> + */
> + msleep(20);
> +
> + ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_DIS_WAKE_UP, 1);
> + if (ret)
> + goto err;
> + ret = bma180_set_ee_writing_state(data, 1);
> + if (ret)
> + goto err;
> + ret = bma180_set_new_data_intr_state(data, 0);
> + if (ret)
> + goto err;
> + ret = bma180_set_bits(data, BMA180_BW_TCS, BMA180_BW, data->bw);
> + if (ret)
> + goto err;
> + ret = bma180_set_bits(data,
> + BMA180_OFFSET_LSB1, BMA180_RANGE, data->range);
> + if (ret)
> + goto err;
> + ret = bma180_set_bits(data, BMA180_TCO_Z, BMA180_MODE_CONFIG,
> + data->mode ? BMA180_LOW_POWER : BMA180_LOW_NOISE);
> + if (ret)
> + goto err;
> + ret = bma180_set_bits(data, BMA180_OFFSET_LSB1, BMA180_SMP_SKIP, 1);
> + if (ret)
> + goto err;
> + ret = bma180_set_new_data_intr_state(data, 1);
> + if (ret)
> + goto err;
> + ret = bma180_set_ee_writing_state(data, 0);
> + if (ret)
> + goto err;
> +
> + return 0;
> +
> +err:
> + dev_err(&data->client->dev, "failed to init the chip\n");
> + return ret;
> +}
> +
> +static void bma180_chip_disable(struct bma180_data *data)
> +{
> + if (bma180_set_ee_writing_state(data, 1))
> + goto err;
> + if (bma180_set_new_data_intr_state(data, 0))
> + goto err;
> + if (bma180_set_ee_writing_state(data, 0))
> + goto err;
> + if (bma180_set_sleep_state(data, 1))
> + goto err;
> +
> + return;
> +
> +err:
> + dev_err(&data->client->dev, "failed to disable the chip\n");
> +}
> +
> +static int bma180_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan, int *val, int *val2,
> + long mask)
> +{
> + struct bma180_data *data = iio_priv(indio_dev);
> + long tmp = ((s16)data->acc_reg[chan->channel] >> 2)
> + * bma180_range_table[data->range].ratio;
> +
> + if (data->acc_reg[chan->channel] < 0)
> + return data->acc_reg[chan->channel];
> +
> + *val = tmp / 1000000;
> + *val2 = (tmp % 1000000);
> +
> + return IIO_VAL_INT_PLUS_MICRO;
> +}
> +
> +static const struct iio_info bma180_info = {
> + .driver_module = THIS_MODULE,
> + .read_raw = &bma180_read_raw,
> +};
> +
> +static const struct iio_chan_spec bma180_channels[] = {
> + {
> + .type = IIO_ACCEL,
> + .channel = AXIS_X,
> + .channel2 = IIO_MOD_X,
> + .indexed = true,

do the channels need to be indexed?

> + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
> + }, {
> + .type = IIO_ACCEL,
> + .channel = AXIS_Y,
> + .channel2 = IIO_MOD_Y,
> + .indexed = true,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
> + }, {
> + .type = IIO_ACCEL,
> + .channel = AXIS_Z,
> + .channel2 = IIO_MOD_Z,
> + .indexed = true,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
> + },
> +};
> +
> +static irqreturn_t bma180_interrupt_handler(int irq, void *private)
> +{
> + struct iio_dev *dev_info = private;
> + struct bma180_data *data = iio_priv(dev_info);
> + int i;
> +
> + mutex_lock(&data->mutex);
> + for (i = AXIS_X; i <= AXIS_Z; ++i)
> + data->acc_reg[i] = bma180_get_acc_reg(data, i);
> + mutex_unlock(&data->mutex);
> +
> + input_report_abs(data->input_dev, ABS_X, data->acc_reg[AXIS_X]);
> + input_report_abs(data->input_dev, ABS_Y, data->acc_reg[AXIS_Y]);
> + input_report_abs(data->input_dev, ABS_Z, data->acc_reg[AXIS_Z]);

input subsystem stuff within IIO?
uhoh...

the driver should probably support more iio features: trigger, scan_mode,
buffer

> + input_sync(data->input_dev);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int bma180_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct input_dev *input_dev;
> + struct bma180_data *data;
> + struct iio_dev *indio_dev;
> + struct device_node *np = client->dev.of_node;
> + int i, ret;
> +
> + if (!client->irq) {
> + dev_err(&client->dev, "this driver cann't work without IRQ\n");

can't

> + return -ENODEV;
> + }
> +
> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + input_dev = input_allocate_device();
> + if (!input_dev)
> + return -ENOMEM;
> +
> + data = iio_priv(indio_dev);
> + i2c_set_clientdata(client, indio_dev);
> + data->client = client;
> +
> + of_property_read_u32(np, "bw", &data->bw);
> + of_property_read_u32(np, "range", &data->range);
> + of_property_read_u32(np, "mode", &data->mode);
> + of_property_read_u32(np, "fuzz", &data->fuzz);
> +
> + ret = bma180_chip_init(data);
> + if (ret < 0)
> + goto err_1;
> +
> + mutex_init(&data->mutex);
> +
> + indio_dev->dev.parent = &client->dev;
> + indio_dev->channels = bma180_channels;
> + indio_dev->num_channels = ARRAY_SIZE(bma180_channels);
> + indio_dev->name = BMA180_DRV_NAME;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->info = &bma180_info;
> +
> + input_dev->name = BMA180_DRV_NAME;
> + input_dev->id.bustype = BUS_I2C;
> + __set_bit(EV_ABS, input_dev->evbit);
> + for (i = ABS_X; i <= ABS_Z; ++i)
> + input_set_abs_params(input_dev, i,
> + -bma180_range_table[data->range].g_range,
> + bma180_range_table[data->range].g_range,
> + data->fuzz, 0);
> + input_dev->dev.parent = &client->dev;
> + input_set_drvdata(input_dev, data);
> +
> + data->input_dev = input_dev;
> +
> + ret = devm_request_threaded_irq(&client->dev, client->irq,
> + NULL, bma180_interrupt_handler, IRQF_ONESHOT,
> + BMA180_IRQ_NAME, indio_dev);
> + if (ret < 0) {
> + dev_err(&client->dev, "irq request error %d\n", -ret);
> + goto err_1;
> + }
> +
> + ret = input_register_device(input_dev);
> + if (ret) {
> + dev_err(&client->dev, "unable to register input device\n");
> + goto err_1;
> + }
> +
> +

extra newline

> + ret = iio_device_register(indio_dev);
> + if (ret < 0) {
> + dev_err(&client->dev, "unable to register iio device\n");
> + goto err_2;
> + }
> +
> + return 0;
> +
> +err_2:
> + input_unregister_device(input_dev);
> +err_1:
> + input_free_device(input_dev);
> +
> + bma180_chip_disable(data);
> +
> + return ret;
> +}
> +
> +static int bma180_remove(struct i2c_client *client)
> +{
> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
> + struct bma180_data *data = iio_priv(indio_dev);
> +
> + iio_device_unregister(indio_dev);
> + input_unregister_device(data->input_dev);
> +
> + mutex_lock(&data->mutex);
> + bma180_chip_disable(data);
> + mutex_unlock(&data->mutex);
> +
> + return 0;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int bma180_suspend(struct device *dev)
> +{
> + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> + struct bma180_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + mutex_lock(&data->mutex);
> + ret = bma180_set_sleep_state(data, 1);
> + mutex_unlock(&data->mutex);
> +
> + return ret;
> +}
> +
> +static int bma180_resume(struct device *dev)
> +{
> + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> + struct bma180_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + mutex_lock(&data->mutex);
> + ret = bma180_set_sleep_state(data, 0);
> + mutex_unlock(&data->mutex);
> +
> + return ret;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(bma180_pm_ops, bma180_suspend, bma180_resume);
> +#define BMA180_PM_OPS (&bma180_pm_ops)
> +#else
> +#define BMA180_PM_OPS NULL
> +#endif
> +
> +static struct i2c_device_id bma180_id[] = {
> + { BMA180_DRV_NAME, 0 },
> + { }
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, bma180_id);
> +
> +static struct i2c_driver bma180_driver = {
> + .driver = {
> + .name = BMA180_DRV_NAME,
> + .owner = THIS_MODULE,
> + .pm = BMA180_PM_OPS,
> + },
> + .probe = bma180_probe,
> + .remove = bma180_remove,
> + .id_table = bma180_id,
> +};
> +
> +module_i2c_driver(bma180_driver);
> +
> +MODULE_AUTHOR("Kravchenko Oleksandr <x0199363@ti.com>");
> +MODULE_AUTHOR("Texas Instruments, Inc.");
> +MODULE_DESCRIPTION("Bosch BMA180 triaxial acceleration sensor");
> +MODULE_LICENSE("GPL");
>

--

Peter Meerwald
+43-664-2444418 (mobile)
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