Commit 8f2273b1 authored by Alexandru Ardelean's avatar Alexandru Ardelean Committed by Jonathan Cameron
Browse files

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: 66614ab2 ("staging: iio: adc: ad7192: removed spi_device_id")
Signed-off-by: default avatarAlexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent a0747914

drivers/iio/adc/ad7192.c

+47 −16
Original line number Diff line number Diff line
@@ -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;

CRA Git | Maintained and supported by SUSTech CRA and CCSE