[PATCH v4 2/2] iio: adc: vf610_adc: limit i.MX6SX's channel number to 4

[Frank Li <Frank.Li@nxp.com>]

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@nxp.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
compatible string 'fsl,imx6sx-adc' already document in
Documentation/devicetree/bindings/iio/adc/fsl,vf610-adc.yaml
Change from v3 to v4
- Add struct vf610_chip_info to avoid cast int to void*

Change from v2 to v3
- none

Change from v1 to v2
- Add Haibo Chen <haibo.chen@nxp.com>
- change cast to uintptr_t to fix below warning

| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411052345.gyJaM3h4-lkp@intel.com/
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 | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/vf610_adc.c b/drivers/iio/adc/vf610_adc.c
index d4b778799755b..6f66bd7ff8eca 100644
--- a/drivers/iio/adc/vf610_adc.c
+++ b/drivers/iio/adc/vf610_adc.c
@@ -177,6 +177,10 @@ struct vf610_adc {
 	} scan;
 };
 
+struct vf610_chip_info {
+	u8 num_channels;
+};
+
 static const u32 vf610_hw_avgs[] = { 1, 4, 8, 16, 32 };
 static const u32 vf610_lst_adder[] = { 3, 5, 7, 9, 13, 17, 21, 25 };
 
@@ -808,8 +812,17 @@ static const struct iio_info vf610_adc_iio_info = {
 	.attrs = &vf610_attribute_group,
 };
 
+static const struct vf610_chip_info vf610_chip_info = {
+	.num_channels = ARRAY_SIZE(vf610_adc_iio_channels),
+};
+
+static const struct vf610_chip_info imx6sx_chip_info = {
+	.num_channels = 4,
+};
+
 static const struct of_device_id vf610_adc_match[] = {
-	{ .compatible = "fsl,vf610-adc", },
+	{ .compatible = "fsl,imx6sx-adc", .data = &imx6sx_chip_info},
+	{ .compatible = "fsl,vf610-adc", .data = &vf610_chip_info},
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, vf610_adc_match);
@@ -824,6 +837,7 @@ static void vf610_adc_action_remove(void *d)
 
 static int vf610_adc_probe(struct platform_device *pdev)
 {
+	const struct vf610_chip_info *chip_info;
 	struct device *dev = &pdev->dev;
 	struct vf610_adc *info;
 	struct iio_dev *indio_dev;
@@ -841,6 +855,10 @@ static int vf610_adc_probe(struct platform_device *pdev)
 	if (IS_ERR(info->regs))
 		return PTR_ERR(info->regs);
 
+	chip_info = device_get_match_data(dev);
+	if (!chip_info)
+		return -EINVAL;
+
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
 		return irq;
@@ -882,7 +900,7 @@ 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 = chip_info->num_channels;
 
 	vf610_adc_cfg_init(info);
 	vf610_adc_hw_init(info);
-- 
2.34.1