linux_dsm_epyc7002/drivers/iio/pressure/mpl3115.c
Peter Rosin 9cf6cdba58 iio: pressure: mpl3115: do not rely on structure field ordering
Fixes a regression triggered by a change in the layout of
struct iio_chan_spec, but the real bug is in the driver which assumed
a specific structure layout in the first place. Hint: the two bits were
not OR:ed together as implied by the indentation prior to this patch,
there was a comma between them, which accidentally moved the ..._SCALE
bit to the next structure field. That field was .info_mask_shared_by_type
before the _available attributes was added by commit 5123960007
("iio:core: add a callback to allow drivers to provide _available
attributes") and .info_mask_separate_available afterwards, and the
regression happened.

info_mask_shared_by_type is actually a better choice than the originally
intended info_mask_separate for the ..._SCALE bit since a constant is
returned from mpl3115_read_raw for the scale. Using
info_mask_shared_by_type also preserves the behavior from before the
regression and is therefore less likely to cause other interesting side
effects.

The above mentioned regression causes an unintended sysfs attibute to
show up that is not backed by code, in turn causing the following NULL
pointer defererence to happen on access.

Segmentation fault

Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = ecc3c000
[00000000] *pgd=87f91831
Internal error: Oops: 80000007 [#1] SMP ARM
Modules linked in:
CPU: 1 PID: 1051 Comm: cat Not tainted 4.10.0-rc5-00009-gffd8858-dirty #3
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
task: ed54ec00 task.stack: ee2bc000
PC is at 0x0
LR is at iio_read_channel_info_avail+0x40/0x280
pc : [<00000000>]    lr : [<c06fbc1c>]    psr: a0070013
sp : ee2bdda8  ip : 00000000  fp : ee2bddf4
r10: c0a53c74  r9 : ed79f000  r8 : ee8d1018
r7 : 00001000  r6 : 00000fff  r5 : ee8b9a00  r4 : ed79f000
r3 : ee2bddc4  r2 : ee2bddbc  r1 : c0a86dcc  r0 : ee8d1000
Flags: NzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
Control: 10c5387d  Table: 3cc3c04a  DAC: 00000051
Process cat (pid: 1051, stack limit = 0xee2bc210)
Stack: (0xee2bdda8 to 0xee2be000)
dda0:                   ee2bddc0 00000002 c016d720 c016d394 ed54ec00 00000000
ddc0: 60070013 ed413780 00000001 edffd480 ee8b9a00 00000fff 00001000 ee8d1018
dde0: ed79f000 c0a53c74 ee2bde0c ee2bddf8 c0513c58 c06fbbe8 edffd480 edffd540
de00: ee2bde3c ee2bde10 c0293474 c0513c40 c02933e4 ee2bde60 00000001 ed413780
de20: 00000001 ed413780 00000000 edffd480 ee2bde4c ee2bde40 c0291d00 c02933f0
de40: ee2bde9c ee2bde50 c024679c c0291ce0 edffd4b0 b6e37000 00020000 ee2bdf78
de60: 00000000 00000000 ed54ec00 ed013200 00000817 c0a111fc edffd540 ed413780
de80: b6e37000 00020000 00020000 ee2bdf78 ee2bded4 ee2bdea0 c0292890 c0246604
dea0: c0117940 c016ba50 00000025 c0a111fc b6e37000 ed413780 ee2bdf78 00020000
dec0: ee2bc000 b6e37000 ee2bdf44 ee2bded8 c021d158 c0292770 c0117764 b6e36004
dee0: c0f0d7c4 ee2bdfb0 b6f89228 00021008 ee2bdfac ee2bdf00 c0101374 c0117770
df00: 00000000 00000000 ee2bc000 00000000 ee2bdf34 ee2bdf20 c016ba04 c0171080
df20: 00000000 00020000 ed413780 b6e37000 00000000 ee2bdf78 ee2bdf74 ee2bdf48
df40: c021e7a0 c021d130 c023e300 c023e280 ee2bdf74 00000000 00000000 ed413780
df60: ed413780 00020000 ee2bdfa4 ee2bdf78 c021e870 c021e71c 00000000 00000000
df80: 00020000 00020000 b6e37000 00000003 c0108084 00000000 00000000 ee2bdfa8
dfa0: c0107ee0 c021e838 00020000 00020000 00000003 b6e37000 00020000 0001a2b4
dfc0: 00020000 00020000 b6e37000 00000003 7fffe000 00000000 00000000 00020000
dfe0: 00000000 be98eb4c 0000c740 b6f1985c 60070010 00000003 00000000 00000000
Backtrace:
[<c06fbbdc>] (iio_read_channel_info_avail) from [<c0513c58>] (dev_attr_show+0x24/0x50)
 r10:c0a53c74 r9:ed79f000 r8:ee8d1018 r7:00001000 r6:00000fff r5:ee8b9a00
 r4:edffd480
[<c0513c34>] (dev_attr_show) from [<c0293474>] (sysfs_kf_seq_show+0x90/0x110)
 r5:edffd540 r4:edffd480
[<c02933e4>] (sysfs_kf_seq_show) from [<c0291d00>] (kernfs_seq_show+0x2c/0x30)
 r10:edffd480 r9:00000000 r8:ed413780 r7:00000001 r6:ed413780 r5:00000001
 r4:ee2bde60 r3:c02933e4
[<c0291cd4>] (kernfs_seq_show) from [<c024679c>] (seq_read+0x1a4/0x4e0)
[<c02465f8>] (seq_read) from [<c0292890>] (kernfs_fop_read+0x12c/0x1cc)
 r10:ee2bdf78 r9:00020000 r8:00020000 r7:b6e37000 r6:ed413780 r5:edffd540
 r4:c0a111fc
[<c0292764>] (kernfs_fop_read) from [<c021d158>] (__vfs_read+0x34/0x118)
 r10:b6e37000 r9:ee2bc000 r8:00020000 r7:ee2bdf78 r6:ed413780 r5:b6e37000
 r4:c0a111fc
[<c021d124>] (__vfs_read) from [<c021e7a0>] (vfs_read+0x90/0x11c)
 r8:ee2bdf78 r7:00000000 r6:b6e37000 r5:ed413780 r4:00020000
[<c021e710>] (vfs_read) from [<c021e870>] (SyS_read+0x44/0x90)
 r8:00020000 r7:ed413780 r6:ed413780 r5:00000000 r4:00000000
[<c021e82c>] (SyS_read) from [<c0107ee0>] (ret_fast_syscall+0x0/0x1c)
 r10:00000000 r8:c0108084 r7:00000003 r6:b6e37000 r5:00020000 r4:00020000
Code: bad PC value
---[ end trace 9c4938ccd0389004 ]---

Fixes: cc26ad455f ("iio: Add Freescale MPL3115A2 pressure / temperature sensor driver")
Fixes: 5123960007 ("iio:core: add a callback to allow drivers to provide _available attributes")
Reported-by: Ken Lin <ken.lin@advantech.com>
Tested-by: Ken Lin <ken.lin@advantech.com>
Signed-off-by: Peter Rosin <peda@axentia.se>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2017-02-11 09:00:20 +00:00

338 lines
7.9 KiB
C

/*
* mpl3115.c - Support for Freescale MPL3115A2 pressure/temperature sensor
*
* Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>
*
* 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.
*
* (7-bit I2C slave address 0x60)
*
* TODO: FIFO buffer, altimeter mode, oversampling, continuous mode,
* interrupts, user offset correction, raw mode
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/buffer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/delay.h>
#define MPL3115_STATUS 0x00
#define MPL3115_OUT_PRESS 0x01 /* MSB first, 20 bit */
#define MPL3115_OUT_TEMP 0x04 /* MSB first, 12 bit */
#define MPL3115_WHO_AM_I 0x0c
#define MPL3115_CTRL_REG1 0x26
#define MPL3115_DEVICE_ID 0xc4
#define MPL3115_STATUS_PRESS_RDY BIT(2)
#define MPL3115_STATUS_TEMP_RDY BIT(1)
#define MPL3115_CTRL_RESET BIT(2) /* software reset */
#define MPL3115_CTRL_OST BIT(1) /* initiate measurement */
#define MPL3115_CTRL_ACTIVE BIT(0) /* continuous measurement */
#define MPL3115_CTRL_OS_258MS (BIT(5) | BIT(4)) /* 64x oversampling */
struct mpl3115_data {
struct i2c_client *client;
struct mutex lock;
u8 ctrl_reg1;
};
static int mpl3115_request(struct mpl3115_data *data)
{
int ret, tries = 15;
/* trigger measurement */
ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
data->ctrl_reg1 | MPL3115_CTRL_OST);
if (ret < 0)
return ret;
while (tries-- > 0) {
ret = i2c_smbus_read_byte_data(data->client, MPL3115_CTRL_REG1);
if (ret < 0)
return ret;
/* wait for data ready, i.e. OST cleared */
if (!(ret & MPL3115_CTRL_OST))
break;
msleep(20);
}
if (tries < 0) {
dev_err(&data->client->dev, "data not ready\n");
return -EIO;
}
return 0;
}
static int mpl3115_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct mpl3115_data *data = iio_priv(indio_dev);
__be32 tmp = 0;
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = iio_device_claim_direct_mode(indio_dev);
if (ret)
return ret;
switch (chan->type) {
case IIO_PRESSURE: /* in 0.25 pascal / LSB */
mutex_lock(&data->lock);
ret = mpl3115_request(data);
if (ret < 0) {
mutex_unlock(&data->lock);
break;
}
ret = i2c_smbus_read_i2c_block_data(data->client,
MPL3115_OUT_PRESS, 3, (u8 *) &tmp);
mutex_unlock(&data->lock);
if (ret < 0)
break;
*val = be32_to_cpu(tmp) >> 12;
ret = IIO_VAL_INT;
break;
case IIO_TEMP: /* in 0.0625 celsius / LSB */
mutex_lock(&data->lock);
ret = mpl3115_request(data);
if (ret < 0) {
mutex_unlock(&data->lock);
break;
}
ret = i2c_smbus_read_i2c_block_data(data->client,
MPL3115_OUT_TEMP, 2, (u8 *) &tmp);
mutex_unlock(&data->lock);
if (ret < 0)
break;
*val = sign_extend32(be32_to_cpu(tmp) >> 20, 11);
ret = IIO_VAL_INT;
break;
default:
ret = -EINVAL;
break;
}
iio_device_release_direct_mode(indio_dev);
return ret;
case IIO_CHAN_INFO_SCALE:
switch (chan->type) {
case IIO_PRESSURE:
*val = 0;
*val2 = 250; /* want kilopascal */
return IIO_VAL_INT_PLUS_MICRO;
case IIO_TEMP:
*val = 0;
*val2 = 62500;
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
}
return -EINVAL;
}
static irqreturn_t mpl3115_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct mpl3115_data *data = iio_priv(indio_dev);
u8 buffer[16]; /* 32-bit channel + 16-bit channel + padding + ts */
int ret, pos = 0;
mutex_lock(&data->lock);
ret = mpl3115_request(data);
if (ret < 0) {
mutex_unlock(&data->lock);
goto done;
}
memset(buffer, 0, sizeof(buffer));
if (test_bit(0, indio_dev->active_scan_mask)) {
ret = i2c_smbus_read_i2c_block_data(data->client,
MPL3115_OUT_PRESS, 3, &buffer[pos]);
if (ret < 0) {
mutex_unlock(&data->lock);
goto done;
}
pos += 4;
}
if (test_bit(1, indio_dev->active_scan_mask)) {
ret = i2c_smbus_read_i2c_block_data(data->client,
MPL3115_OUT_TEMP, 2, &buffer[pos]);
if (ret < 0) {
mutex_unlock(&data->lock);
goto done;
}
}
mutex_unlock(&data->lock);
iio_push_to_buffers_with_timestamp(indio_dev, buffer,
iio_get_time_ns(indio_dev));
done:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static const struct iio_chan_spec mpl3115_channels[] = {
{
.type = IIO_PRESSURE,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
.scan_index = 0,
.scan_type = {
.sign = 'u',
.realbits = 20,
.storagebits = 32,
.shift = 12,
.endianness = IIO_BE,
}
},
{
.type = IIO_TEMP,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
.scan_index = 1,
.scan_type = {
.sign = 's',
.realbits = 12,
.storagebits = 16,
.shift = 4,
.endianness = IIO_BE,
}
},
IIO_CHAN_SOFT_TIMESTAMP(2),
};
static const struct iio_info mpl3115_info = {
.read_raw = &mpl3115_read_raw,
.driver_module = THIS_MODULE,
};
static int mpl3115_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct mpl3115_data *data;
struct iio_dev *indio_dev;
int ret;
ret = i2c_smbus_read_byte_data(client, MPL3115_WHO_AM_I);
if (ret < 0)
return ret;
if (ret != MPL3115_DEVICE_ID)
return -ENODEV;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
data = iio_priv(indio_dev);
data->client = client;
mutex_init(&data->lock);
i2c_set_clientdata(client, indio_dev);
indio_dev->info = &mpl3115_info;
indio_dev->name = id->name;
indio_dev->dev.parent = &client->dev;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = mpl3115_channels;
indio_dev->num_channels = ARRAY_SIZE(mpl3115_channels);
/* software reset, I2C transfer is aborted (fails) */
i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1,
MPL3115_CTRL_RESET);
msleep(50);
data->ctrl_reg1 = MPL3115_CTRL_OS_258MS;
ret = i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1,
data->ctrl_reg1);
if (ret < 0)
return ret;
ret = iio_triggered_buffer_setup(indio_dev, NULL,
mpl3115_trigger_handler, NULL);
if (ret < 0)
return ret;
ret = iio_device_register(indio_dev);
if (ret < 0)
goto buffer_cleanup;
return 0;
buffer_cleanup:
iio_triggered_buffer_cleanup(indio_dev);
return ret;
}
static int mpl3115_standby(struct mpl3115_data *data)
{
return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
data->ctrl_reg1 & ~MPL3115_CTRL_ACTIVE);
}
static int mpl3115_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
iio_device_unregister(indio_dev);
iio_triggered_buffer_cleanup(indio_dev);
mpl3115_standby(iio_priv(indio_dev));
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int mpl3115_suspend(struct device *dev)
{
return mpl3115_standby(iio_priv(i2c_get_clientdata(
to_i2c_client(dev))));
}
static int mpl3115_resume(struct device *dev)
{
struct mpl3115_data *data = iio_priv(i2c_get_clientdata(
to_i2c_client(dev)));
return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
data->ctrl_reg1);
}
static SIMPLE_DEV_PM_OPS(mpl3115_pm_ops, mpl3115_suspend, mpl3115_resume);
#define MPL3115_PM_OPS (&mpl3115_pm_ops)
#else
#define MPL3115_PM_OPS NULL
#endif
static const struct i2c_device_id mpl3115_id[] = {
{ "mpl3115", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, mpl3115_id);
static struct i2c_driver mpl3115_driver = {
.driver = {
.name = "mpl3115",
.pm = MPL3115_PM_OPS,
},
.probe = mpl3115_probe,
.remove = mpl3115_remove,
.id_table = mpl3115_id,
};
module_i2c_driver(mpl3115_driver);
MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
MODULE_DESCRIPTION("Freescale MPL3115 pressure/temperature driver");
MODULE_LICENSE("GPL");