iio: adc: ad7192: fix null pointer de-reference crash during probe

When the 'spi_device_id' table was removed, it omitted to cleanup/fix the
assignment:
   'indio_dev->name = spi_get_device_id(spi)->name;'

After that patch 'spi_get_device_id(spi)' returns NULL, so this crashes
during probe with null de-ref.

This change fixes this by introducing an ad7192_chip_info struct, and
defines all part-names [that should be assigned to indio_dev->name] in a
'ad7192_chip_info_tbl' table.

With this change, the old 'st->devid' is also moved to be a
'chip_info->chip_id'. And the old 'ID_AD719X' macros have been renamed to
'CHIPID_AD719X'. Tld identifiers have been re-purposed to be enum/index
values in the new 'ad7192_chip_info_tbl'.

This should fix the bug, and maintain the ABI for the 'indio_dev->name'
field.

Fixes: 66614ab2be ("staging: iio: adc: ad7192: removed spi_device_id")
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Alexandru Ardelean 2020-04-15 08:58:03 +03:00 committed by Jonathan Cameron
parent a07479147b
commit 8f2273b1e0

View File

@ -125,10 +125,10 @@
#define AD7193_CH_AINCOM 0x600 /* AINCOM - AINCOM */
/* ID Register Bit Designations (AD7192_REG_ID) */
#define ID_AD7190 0x4
#define ID_AD7192 0x0
#define ID_AD7193 0x2
#define ID_AD7195 0x6
#define CHIPID_AD7190 0x4
#define CHIPID_AD7192 0x0
#define CHIPID_AD7193 0x2
#define CHIPID_AD7195 0x6
#define AD7192_ID_MASK 0x0F
/* GPOCON Register Bit Designations (AD7192_REG_GPOCON) */
@ -161,7 +161,20 @@ enum {
AD7192_SYSCALIB_FULL_SCALE,
};
enum {
ID_AD7190,
ID_AD7192,
ID_AD7193,
ID_AD7195,
};
struct ad7192_chip_info {
unsigned int chip_id;
const char *name;
};
struct ad7192_state {
const struct ad7192_chip_info *chip_info;
struct regulator *avdd;
struct regulator *dvdd;
struct clk *mclk;
@ -172,7 +185,6 @@ struct ad7192_state {
u32 conf;
u32 scale_avail[8][2];
u8 gpocon;
u8 devid;
u8 clock_sel;
struct mutex lock; /* protect sensor state */
u8 syscalib_mode[8];
@ -348,7 +360,7 @@ static int ad7192_setup(struct ad7192_state *st, struct device_node *np)
id &= AD7192_ID_MASK;
if (id != st->devid)
if (id != st->chip_info->chip_id)
dev_warn(&st->sd.spi->dev, "device ID query failed (0x%X)\n",
id);
@ -363,7 +375,7 @@ static int ad7192_setup(struct ad7192_state *st, struct device_node *np)
st->mode |= AD7192_MODE_REJ60;
refin2_en = of_property_read_bool(np, "adi,refin2-pins-enable");
if (refin2_en && st->devid != ID_AD7195)
if (refin2_en && st->chip_info->chip_id != CHIPID_AD7195)
st->conf |= AD7192_CONF_REFSEL;
st->conf &= ~AD7192_CONF_CHOP;
@ -859,12 +871,31 @@ static const struct iio_chan_spec ad7193_channels[] = {
IIO_CHAN_SOFT_TIMESTAMP(14),
};
static const struct ad7192_chip_info ad7192_chip_info_tbl[] = {
[ID_AD7190] = {
.chip_id = CHIPID_AD7190,
.name = "ad7190",
},
[ID_AD7192] = {
.chip_id = CHIPID_AD7192,
.name = "ad7192",
},
[ID_AD7193] = {
.chip_id = CHIPID_AD7193,
.name = "ad7193",
},
[ID_AD7195] = {
.chip_id = CHIPID_AD7195,
.name = "ad7195",
},
};
static int ad7192_channels_config(struct iio_dev *indio_dev)
{
struct ad7192_state *st = iio_priv(indio_dev);
switch (st->devid) {
case ID_AD7193:
switch (st->chip_info->chip_id) {
case CHIPID_AD7193:
indio_dev->channels = ad7193_channels;
indio_dev->num_channels = ARRAY_SIZE(ad7193_channels);
break;
@ -878,10 +909,10 @@ static int ad7192_channels_config(struct iio_dev *indio_dev)
}
static const struct of_device_id ad7192_of_match[] = {
{ .compatible = "adi,ad7190", .data = (void *)ID_AD7190 },
{ .compatible = "adi,ad7192", .data = (void *)ID_AD7192 },
{ .compatible = "adi,ad7193", .data = (void *)ID_AD7193 },
{ .compatible = "adi,ad7195", .data = (void *)ID_AD7195 },
{ .compatible = "adi,ad7190", .data = &ad7192_chip_info_tbl[ID_AD7190] },
{ .compatible = "adi,ad7192", .data = &ad7192_chip_info_tbl[ID_AD7192] },
{ .compatible = "adi,ad7193", .data = &ad7192_chip_info_tbl[ID_AD7193] },
{ .compatible = "adi,ad7195", .data = &ad7192_chip_info_tbl[ID_AD7195] },
{}
};
MODULE_DEVICE_TABLE(of, ad7192_of_match);
@ -938,16 +969,16 @@ static int ad7192_probe(struct spi_device *spi)
}
spi_set_drvdata(spi, indio_dev);
st->devid = (unsigned long)of_device_get_match_data(&spi->dev);
st->chip_info = of_device_get_match_data(&spi->dev);
indio_dev->dev.parent = &spi->dev;
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->name = st->chip_info->name;
indio_dev->modes = INDIO_DIRECT_MODE;
ret = ad7192_channels_config(indio_dev);
if (ret < 0)
goto error_disable_dvdd;
if (st->devid == ID_AD7195)
if (st->chip_info->chip_id == CHIPID_AD7195)
indio_dev->info = &ad7195_info;
else
indio_dev->info = &ad7192_info;