From 8f2273b1e036f89bd04eb66bcb6f456eae8c98f1 Mon Sep 17 00:00:00 2001 From: Alexandru Ardelean Date: Wed, 15 Apr 2020 08:58:03 +0300 Subject: [PATCH] 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: 66614ab2be38 ("staging: iio: adc: ad7192: removed spi_device_id") Signed-off-by: Alexandru Ardelean Signed-off-by: Jonathan Cameron --- drivers/iio/adc/ad7192.c | 63 ++++++++++++++++++++++++++++++---------- 1 file changed, 47 insertions(+), 16 deletions(-) diff --git a/drivers/iio/adc/ad7192.c b/drivers/iio/adc/ad7192.c index 02981f3d1794..08ba1a8f05eb 100644 --- a/drivers/iio/adc/ad7192.c +++ b/drivers/iio/adc/ad7192.c @@ -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;