On Thu, 7 Nov 2024 14:18:41 -0500
Frank Li <Frank.Li@xxxxxxx> wrote:
> i.MX6SX only has 4 ADC channels, so limit channel numbers to 4 for
> compatible string 'fsl,imx6sx-adc'.
>
> Reviewed-by: Haibo Chen <haibo.chen@xxxxxxx>
> Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
I'm pretty strongly against putting integers in the id match
data variables. Instead use a much more easily extended structure
(which will have one element for now)
struct vf610_chip_info {
u8 num_channels;
};
and then pointers to that structure in the tables.
The integer path regularly goes wrong (0 causes trouble with error handling)
and so I push back on people doing this in new code.
One other comment inline.
Jonathan
> ---
> compatible string 'fsl,imx6sx-adc' already document in
> Documentation/devicetree/bindings/iio/adc/fsl,vf610-adc.yaml
>
> Change from v2 to v3
> - none
>
> Change from v1 to v2
> - Add Haibo Chen <haibo.chen@xxxxxxx>
> - change cast to uintptr_t to fix below warning
>
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202411052345.gyJaM3h4-lkp@xxxxxxxxx/
> All warnings (new ones prefixed by >>):
>
> In file included from drivers/iio/adc/vf610_adc.c:20: In file included from include/linux/regulator/consumer.h:35:
> In file included from include/linux/suspend.h:5:
> In file included from include/linux/swap.h:9:
> In file included from include/linux/memcontrol.h:21:
> In file included from include/linux/mm.h:2213:
> include/linux/vmstat.h:518:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
> 518 | return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
> | ~~~~~~~~~~~ ^ ~~~>> drivers/iio/adc/vf610_adc.c:874:28: warning: cast to smaller integer type 'u32' (aka 'unsigned int') from 'const void *' [-Wvoid-pointer-to-int-cast]
> 874 | indio_dev->num_channels = (u32)device_get_match_data(dev);
> |
> ---
> drivers/iio/adc/vf610_adc.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/adc/vf610_adc.c b/drivers/iio/adc/vf610_adc.c
> index a6a0ada8a102f..36f6132bf5ba4 100644
> --- a/drivers/iio/adc/vf610_adc.c
> +++ b/drivers/iio/adc/vf610_adc.c
> @@ -809,7 +809,8 @@ static const struct iio_info vf610_adc_iio_info = {
> };
>
> static const struct of_device_id vf610_adc_match[] = {
> - { .compatible = "fsl,vf610-adc", },
> + { .compatible = "fsl,imx6sx-adc", .data = (void *)4},
> + { .compatible = "fsl,vf610-adc", .data = (void *)ARRAY_SIZE(vf610_adc_iio_channels)},
> { /* sentinel */ }
> };
> MODULE_DEVICE_TABLE(of, vf610_adc_match);
> @@ -870,7 +871,7 @@ static int vf610_adc_probe(struct platform_device *pdev)
> indio_dev->info = &vf610_adc_iio_info;
> indio_dev->modes = INDIO_DIRECT_MODE;
> indio_dev->channels = vf610_adc_iio_channels;
> - indio_dev->num_channels = ARRAY_SIZE(vf610_adc_iio_channels);
> + indio_dev->num_channels = (uintptr_t)device_get_match_data(dev);
That can in theory fail and return NULL. Which here would be interpreted
as 0 channels and probably cause trouble later.
>
> vf610_adc_cfg_init(info);
> vf610_adc_hw_init(info);
