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linux-stable/drivers/iio/accel/kxsd9.c
Jonathan Cameron 95ad67577d iio: accel: kxsd9: Fix alignment of local buffer. 
iio_push_to_buffers_with_timestamp assumes 8 byte alignment which
is not guaranteed by an array of smaller elements.

Note that whilst in this particular case the alignment forcing
of the ts element is not strictly necessary it acts as good
documentation.  Doing this where not necessary should cut
down on the number of cut and paste introduced errors elsewhere.

Fixes: 0427a106a9 ("iio: accel: kxsd9: Add triggered buffer handling")
Reported-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: <Stable@vger.kernel.org>
2020-08-22 11:38:47 +01:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* kxsd9.c simple support for the Kionix KXSD9 3D
* accelerometer.
*
* Copyright (c) 2008-2009 Jonathan Cameron <jic23@kernel.org>
*
* The i2c interface is very similar, so shouldn't be a problem once
* I have a suitable wire made up.
*
* TODO: Support the motion detector
*/
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/sysfs.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/regulator/consumer.h>
#include <linux/pm_runtime.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>
#include "kxsd9.h"
#define KXSD9_REG_X 0x00
#define KXSD9_REG_Y 0x02
#define KXSD9_REG_Z 0x04
#define KXSD9_REG_AUX 0x06
#define KXSD9_REG_RESET 0x0a
#define KXSD9_REG_CTRL_C 0x0c
#define KXSD9_CTRL_C_FS_MASK 0x03
#define KXSD9_CTRL_C_FS_8G 0x00
#define KXSD9_CTRL_C_FS_6G 0x01
#define KXSD9_CTRL_C_FS_4G 0x02
#define KXSD9_CTRL_C_FS_2G 0x03
#define KXSD9_CTRL_C_MOT_LAT BIT(3)
#define KXSD9_CTRL_C_MOT_LEV BIT(4)
#define KXSD9_CTRL_C_LP_MASK 0xe0
#define KXSD9_CTRL_C_LP_NONE 0x00
#define KXSD9_CTRL_C_LP_2000HZC BIT(5)
#define KXSD9_CTRL_C_LP_2000HZB BIT(6)
#define KXSD9_CTRL_C_LP_2000HZA (BIT(5)|BIT(6))
#define KXSD9_CTRL_C_LP_1000HZ BIT(7)
#define KXSD9_CTRL_C_LP_500HZ (BIT(7)|BIT(5))
#define KXSD9_CTRL_C_LP_100HZ (BIT(7)|BIT(6))
#define KXSD9_CTRL_C_LP_50HZ (BIT(7)|BIT(6)|BIT(5))
#define KXSD9_REG_CTRL_B 0x0d
#define KXSD9_CTRL_B_CLK_HLD BIT(7)
#define KXSD9_CTRL_B_ENABLE BIT(6)
#define KXSD9_CTRL_B_ST BIT(5) /* Self-test */
#define KXSD9_REG_CTRL_A 0x0e
/**
* struct kxsd9_state - device related storage
* @dev: pointer to the parent device
* @map: regmap to the device
* @orientation: mounting matrix, flipped axis etc
* @regs: regulators for this device, VDD and IOVDD
* @scale: the current scaling setting
*/
struct kxsd9_state {
struct device *dev;
struct regmap *map;
struct iio_mount_matrix orientation;
struct regulator_bulk_data regs[2];
u8 scale;
};
#define KXSD9_SCALE_2G "0.011978"
#define KXSD9_SCALE_4G "0.023927"
#define KXSD9_SCALE_6G "0.035934"
#define KXSD9_SCALE_8G "0.047853"
/* reverse order */
static const int kxsd9_micro_scales[4] = { 47853, 35934, 23927, 11978 };
#define KXSD9_ZERO_G_OFFSET -2048
/*
* Regulator names
*/
static const char kxsd9_reg_vdd[] = "vdd";
static const char kxsd9_reg_iovdd[] = "iovdd";
static int kxsd9_write_scale(struct iio_dev *indio_dev, int micro)
{
int ret, i;
struct kxsd9_state *st = iio_priv(indio_dev);
bool foundit = false;
for (i = 0; i < 4; i++)
if (micro == kxsd9_micro_scales[i]) {
foundit = true;
break;
}
if (!foundit)
return -EINVAL;
ret = regmap_update_bits(st->map,
KXSD9_REG_CTRL_C,
KXSD9_CTRL_C_FS_MASK,
i);
if (ret < 0)
goto error_ret;
/* Cached scale when the sensor is powered down */
st->scale = i;
error_ret:
return ret;
}
static IIO_CONST_ATTR(accel_scale_available,
KXSD9_SCALE_2G " "
KXSD9_SCALE_4G " "
KXSD9_SCALE_6G " "
KXSD9_SCALE_8G);
static struct attribute *kxsd9_attributes[] = {
&iio_const_attr_accel_scale_available.dev_attr.attr,
NULL,
};
static int kxsd9_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long mask)
{
int ret = -EINVAL;
struct kxsd9_state *st = iio_priv(indio_dev);
pm_runtime_get_sync(st->dev);
if (mask == IIO_CHAN_INFO_SCALE) {
/* Check no integer component */
if (val)
return -EINVAL;
ret = kxsd9_write_scale(indio_dev, val2);
}
pm_runtime_mark_last_busy(st->dev);
pm_runtime_put_autosuspend(st->dev);
return ret;
}
static int kxsd9_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
int ret = -EINVAL;
struct kxsd9_state *st = iio_priv(indio_dev);
unsigned int regval;
__be16 raw_val;
u16 nval;
pm_runtime_get_sync(st->dev);
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = regmap_bulk_read(st->map, chan->address, &raw_val,
sizeof(raw_val));
if (ret)
goto error_ret;
nval = be16_to_cpu(raw_val);
/* Only 12 bits are valid */
nval >>= 4;
*val = nval;
ret = IIO_VAL_INT;
break;
case IIO_CHAN_INFO_OFFSET:
/* This has a bias of -2048 */
*val = KXSD9_ZERO_G_OFFSET;
ret = IIO_VAL_INT;
break;
case IIO_CHAN_INFO_SCALE:
ret = regmap_read(st->map,
KXSD9_REG_CTRL_C,
&regval);
if (ret < 0)
goto error_ret;
*val = 0;
*val2 = kxsd9_micro_scales[regval & KXSD9_CTRL_C_FS_MASK];
ret = IIO_VAL_INT_PLUS_MICRO;
break;
}
error_ret:
pm_runtime_mark_last_busy(st->dev);
pm_runtime_put_autosuspend(st->dev);
return ret;
};
static irqreturn_t kxsd9_trigger_handler(int irq, void *p)
{
const struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct kxsd9_state *st = iio_priv(indio_dev);
/*
* Ensure correct positioning and alignment of timestamp.
* No need to zero initialize as all elements written.
*/
struct {
__be16 chan[4];
s64 ts __aligned(8);
} hw_values;
int ret;
ret = regmap_bulk_read(st->map,
KXSD9_REG_X,
hw_values.chan,
sizeof(hw_values.chan));
if (ret) {
dev_err(st->dev,
"error reading data\n");
return ret;
}
iio_push_to_buffers_with_timestamp(indio_dev,
&hw_values,
iio_get_time_ns(indio_dev));
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static int kxsd9_buffer_preenable(struct iio_dev *indio_dev)
{
struct kxsd9_state *st = iio_priv(indio_dev);
pm_runtime_get_sync(st->dev);
return 0;
}
static int kxsd9_buffer_postdisable(struct iio_dev *indio_dev)
{
struct kxsd9_state *st = iio_priv(indio_dev);
pm_runtime_mark_last_busy(st->dev);
pm_runtime_put_autosuspend(st->dev);
return 0;
}
static const struct iio_buffer_setup_ops kxsd9_buffer_setup_ops = {
.preenable = kxsd9_buffer_preenable,
.postdisable = kxsd9_buffer_postdisable,
};
static const struct iio_mount_matrix *
kxsd9_get_mount_matrix(const struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
struct kxsd9_state *st = iio_priv(indio_dev);
return &st->orientation;
}
static const struct iio_chan_spec_ext_info kxsd9_ext_info[] = {
IIO_MOUNT_MATRIX(IIO_SHARED_BY_TYPE, kxsd9_get_mount_matrix),
{ },
};
#define KXSD9_ACCEL_CHAN(axis, index) \
{ \
.type = IIO_ACCEL, \
.modified = 1, \
.channel2 = IIO_MOD_##axis, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
BIT(IIO_CHAN_INFO_OFFSET), \
.ext_info = kxsd9_ext_info, \
.address = KXSD9_REG_##axis, \
.scan_index = index, \
.scan_type = { \
.sign = 'u', \
.realbits = 12, \
.storagebits = 16, \
.shift = 4, \
.endianness = IIO_BE, \
}, \
}
static const struct iio_chan_spec kxsd9_channels[] = {
KXSD9_ACCEL_CHAN(X, 0),
KXSD9_ACCEL_CHAN(Y, 1),
KXSD9_ACCEL_CHAN(Z, 2),
{
.type = IIO_VOLTAGE,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.indexed = 1,
.address = KXSD9_REG_AUX,
.scan_index = 3,
.scan_type = {
.sign = 'u',
.realbits = 12,
.storagebits = 16,
.shift = 4,
.endianness = IIO_BE,
},
},
IIO_CHAN_SOFT_TIMESTAMP(4),
};
static const struct attribute_group kxsd9_attribute_group = {
.attrs = kxsd9_attributes,
};
static int kxsd9_power_up(struct kxsd9_state *st)
{
int ret;
/* Enable the regulators */
ret = regulator_bulk_enable(ARRAY_SIZE(st->regs), st->regs);
if (ret) {
dev_err(st->dev, "Cannot enable regulators\n");
return ret;
}
/* Power up */
ret = regmap_write(st->map,
KXSD9_REG_CTRL_B,
KXSD9_CTRL_B_ENABLE);
if (ret)
return ret;
/*
* Set 1000Hz LPF, 2g fullscale, motion wakeup threshold 1g,
* latched wakeup
*/
ret = regmap_write(st->map,
KXSD9_REG_CTRL_C,
KXSD9_CTRL_C_LP_1000HZ |
KXSD9_CTRL_C_MOT_LEV |
KXSD9_CTRL_C_MOT_LAT |
st->scale);
if (ret)
return ret;
/*
* Power-up time depends on the LPF setting, but typ 15.9 ms, let's
* set 20 ms to allow for some slack.
*/
msleep(20);
return 0;
};
static int kxsd9_power_down(struct kxsd9_state *st)
{
int ret;
/*
* Set into low power mode - since there may be more users of the
* regulators this is the first step of the power saving: it will
* make sure we conserve power even if there are others users on the
* regulators.
*/
ret = regmap_update_bits(st->map,
KXSD9_REG_CTRL_B,
KXSD9_CTRL_B_ENABLE,
0);
if (ret)
return ret;
/* Disable the regulators */
ret = regulator_bulk_disable(ARRAY_SIZE(st->regs), st->regs);
if (ret) {
dev_err(st->dev, "Cannot disable regulators\n");
return ret;
}
return 0;
}
static const struct iio_info kxsd9_info = {
.read_raw = &kxsd9_read_raw,
.write_raw = &kxsd9_write_raw,
.attrs = &kxsd9_attribute_group,
};
/* Four channels apart from timestamp, scan mask = 0x0f */
static const unsigned long kxsd9_scan_masks[] = { 0xf, 0 };
int kxsd9_common_probe(struct device *dev,
struct regmap *map,
const char *name)
{
struct iio_dev *indio_dev;
struct kxsd9_state *st;
int ret;
indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
st = iio_priv(indio_dev);
st->dev = dev;
st->map = map;
indio_dev->channels = kxsd9_channels;
indio_dev->num_channels = ARRAY_SIZE(kxsd9_channels);
indio_dev->name = name;
indio_dev->info = &kxsd9_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->available_scan_masks = kxsd9_scan_masks;
/* Read the mounting matrix, if present */
ret = iio_read_mount_matrix(dev, "mount-matrix", &st->orientation);
if (ret)
return ret;
/* Fetch and turn on regulators */
st->regs[0].supply = kxsd9_reg_vdd;
st->regs[1].supply = kxsd9_reg_iovdd;
ret = devm_regulator_bulk_get(dev,
ARRAY_SIZE(st->regs),
st->regs);
if (ret) {
dev_err(dev, "Cannot get regulators\n");
return ret;
}
/* Default scaling */
st->scale = KXSD9_CTRL_C_FS_2G;
kxsd9_power_up(st);
ret = iio_triggered_buffer_setup(indio_dev,
iio_pollfunc_store_time,
kxsd9_trigger_handler,
&kxsd9_buffer_setup_ops);
if (ret) {
dev_err(dev, "triggered buffer setup failed\n");
goto err_power_down;
}
ret = iio_device_register(indio_dev);
if (ret)
goto err_cleanup_buffer;
dev_set_drvdata(dev, indio_dev);
/* Enable runtime PM */
pm_runtime_get_noresume(dev);
pm_runtime_set_active(dev);
pm_runtime_enable(dev);
/*
* Set autosuspend to two orders of magnitude larger than the
* start-up time. 20ms start-up time means 2000ms autosuspend,
* i.e. 2 seconds.
*/
pm_runtime_set_autosuspend_delay(dev, 2000);
pm_runtime_use_autosuspend(dev);
pm_runtime_put(dev);
return 0;
err_cleanup_buffer:
iio_triggered_buffer_cleanup(indio_dev);
err_power_down:
kxsd9_power_down(st);
return ret;
}
EXPORT_SYMBOL(kxsd9_common_probe);
int kxsd9_common_remove(struct device *dev)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct kxsd9_state *st = iio_priv(indio_dev);
iio_triggered_buffer_cleanup(indio_dev);
iio_device_unregister(indio_dev);
pm_runtime_get_sync(dev);
pm_runtime_put_noidle(dev);
pm_runtime_disable(dev);
kxsd9_power_down(st);
return 0;
}
EXPORT_SYMBOL(kxsd9_common_remove);
#ifdef CONFIG_PM
static int kxsd9_runtime_suspend(struct device *dev)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct kxsd9_state *st = iio_priv(indio_dev);
return kxsd9_power_down(st);
}
static int kxsd9_runtime_resume(struct device *dev)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct kxsd9_state *st = iio_priv(indio_dev);
return kxsd9_power_up(st);
}
#endif /* CONFIG_PM */
const struct dev_pm_ops kxsd9_dev_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
pm_runtime_force_resume)
SET_RUNTIME_PM_OPS(kxsd9_runtime_suspend,
kxsd9_runtime_resume, NULL)
};
EXPORT_SYMBOL(kxsd9_dev_pm_ops);
MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
MODULE_DESCRIPTION("Kionix KXSD9 driver");
MODULE_LICENSE("GPL v2");
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