[PATCH] hwmon: (gsc-hwmon) Switch to flexible array to simplify code

From: Christophe JAILLET
Date: Sun Nov 20 2022 - 04:34:54 EST


Using flexible array is more straight forward. It
- saves 1 pointer in the 'gsc_hwmon_platform_data' structure
- saves an indirection when using this array
- saves some LoC and avoids some always spurious pointer arithmetic

Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
Compile tested only
---
drivers/hwmon/gsc-hwmon.c | 6 ++----
include/linux/platform_data/gsc_hwmon.h | 5 ++---
2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/hwmon/gsc-hwmon.c b/drivers/hwmon/gsc-hwmon.c
index b60ec95b5edb..73e5d92b200b 100644
--- a/drivers/hwmon/gsc-hwmon.c
+++ b/drivers/hwmon/gsc-hwmon.c
@@ -257,13 +257,10 @@ gsc_hwmon_get_devtree_pdata(struct device *dev)
if (nchannels == 0)
return ERR_PTR(-ENODEV);

- pdata = devm_kzalloc(dev,
- sizeof(*pdata) + nchannels * sizeof(*ch),
+ pdata = devm_kzalloc(dev, struct_size(pdata, channels, nchannels),
GFP_KERNEL);
if (!pdata)
return ERR_PTR(-ENOMEM);
- ch = (struct gsc_hwmon_channel *)(pdata + 1);
- pdata->channels = ch;
pdata->nchannels = nchannels;

/* fan controller base address */
@@ -277,6 +274,7 @@ gsc_hwmon_get_devtree_pdata(struct device *dev)

of_node_put(fan);

+ ch = pdata->channels;
/* allocate structures for channels and count instances of each type */
device_for_each_child_node(dev, child) {
if (fwnode_property_read_string(child, "label", &ch->name)) {
diff --git a/include/linux/platform_data/gsc_hwmon.h b/include/linux/platform_data/gsc_hwmon.h
index 281f499eda97..f2781aa7eff8 100644
--- a/include/linux/platform_data/gsc_hwmon.h
+++ b/include/linux/platform_data/gsc_hwmon.h
@@ -29,18 +29,17 @@ struct gsc_hwmon_channel {

/**
* struct gsc_hwmon_platform_data - platform data for gsc_hwmon driver
- * @channels: pointer to array of gsc_hwmon_channel structures
- * describing channels
* @nchannels: number of elements in @channels array
* @vreference: voltage reference (mV)
* @resolution: ADC bit resolution
* @fan_base: register base for FAN controller
+ * @channels: array of gsc_hwmon_channel structures describing channels
*/
struct gsc_hwmon_platform_data {
- const struct gsc_hwmon_channel *channels;
int nchannels;
unsigned int resolution;
unsigned int vreference;
unsigned int fan_base;
+ struct gsc_hwmon_channel channels[];
};
#endif
--
2.34.1