[PATCH] leds: qcom-lpg: allocate channels with main struct

[Rosen Penev <rosenp@gmail.com>]

Use a flexible array member to combine kzalloc and kcalloc. This
required moving the struct lpg_channel definition up as flexible array
members require a full definition.

Add __counted_by for extra runtime analysis.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/leds/rgb/leds-qcom-lpg.c | 117 +++++++++++++++----------------
 1 file changed, 56 insertions(+), 61 deletions(-)

diff --git a/drivers/leds/rgb/leds-qcom-lpg.c b/drivers/leds/rgb/leds-qcom-lpg.c
index f6061c47f863..83cedf4a0cbf 100644
--- a/drivers/leds/rgb/leds-qcom-lpg.c
+++ b/drivers/leds/rgb/leds-qcom-lpg.c
@@ -80,58 +80,8 @@
 #define SDAM_PAUSE_HI_MULTIPLIER_OFFSET	0x8
 #define SDAM_PAUSE_LO_MULTIPLIER_OFFSET	0x9
 
-struct lpg_channel;
 struct lpg_data;
 
-/**
- * struct lpg - LPG device context
- * @dev:	pointer to LPG device
- * @map:	regmap for register access
- * @lock:	used to synchronize LED and pwm callback requests
- * @pwm:	PWM-chip object, if operating in PWM mode
- * @data:	reference to version specific data
- * @lut_base:	base address of the LUT block (optional)
- * @lut_size:	number of entries in the LUT block
- * @lut_bitmap:	allocation bitmap for LUT entries
- * @pbs_dev:	PBS device
- * @lpg_chan_sdam:	LPG SDAM peripheral device
- * @lut_sdam:	LUT SDAM peripheral device
- * @pbs_en_bitmap:	bitmap for tracking PBS triggers
- * @triled_base: base address of the TRILED block (optional)
- * @triled_src:	power-source for the TRILED
- * @triled_has_atc_ctl:	true if there is TRI_LED_ATC_CTL register
- * @triled_has_src_sel:	true if there is TRI_LED_SRC_SEL register
- * @channels:	list of PWM channels
- * @num_channels: number of @channels
- */
-struct lpg {
-	struct device *dev;
-	struct regmap *map;
-
-	struct mutex lock;
-
-	struct pwm_chip *pwm;
-
-	const struct lpg_data *data;
-
-	u32 lut_base;
-	u32 lut_size;
-	unsigned long *lut_bitmap;
-
-	struct pbs_dev *pbs_dev;
-	struct nvmem_device *lpg_chan_sdam;
-	struct nvmem_device *lut_sdam;
-	unsigned long pbs_en_bitmap;
-
-	u32 triled_base;
-	u32 triled_src;
-	bool triled_has_atc_ctl;
-	bool triled_has_src_sel;
-
-	struct lpg_channel *channels;
-	unsigned int num_channels;
-};
-
 /**
  * struct lpg_channel - per channel data
  * @lpg:	reference to parent lpg
@@ -216,6 +166,55 @@ struct lpg_led {
 	struct lpg_channel *channels[] __counted_by(num_channels);
 };
 
+/**
+ * struct lpg - LPG device context
+ * @dev:	pointer to LPG device
+ * @map:	regmap for register access
+ * @lock:	used to synchronize LED and pwm callback requests
+ * @pwm:	PWM-chip object, if operating in PWM mode
+ * @data:	reference to version specific data
+ * @lut_base:	base address of the LUT block (optional)
+ * @lut_size:	number of entries in the LUT block
+ * @lut_bitmap:	allocation bitmap for LUT entries
+ * @pbs_dev:	PBS device
+ * @lpg_chan_sdam:	LPG SDAM peripheral device
+ * @lut_sdam:	LUT SDAM peripheral device
+ * @pbs_en_bitmap:	bitmap for tracking PBS triggers
+ * @triled_base: base address of the TRILED block (optional)
+ * @triled_src:	power-source for the TRILED
+ * @triled_has_atc_ctl:	true if there is TRI_LED_ATC_CTL register
+ * @triled_has_src_sel:	true if there is TRI_LED_SRC_SEL register
+ * @channels:	list of PWM channels
+ * @num_channels: number of @channels
+ */
+struct lpg {
+	struct device *dev;
+	struct regmap *map;
+
+	struct mutex lock;
+
+	struct pwm_chip *pwm;
+
+	const struct lpg_data *data;
+
+	u32 lut_base;
+	u32 lut_size;
+	unsigned long *lut_bitmap;
+
+	struct pbs_dev *pbs_dev;
+	struct nvmem_device *lpg_chan_sdam;
+	struct nvmem_device *lut_sdam;
+	unsigned long pbs_en_bitmap;
+
+	u32 triled_base;
+	u32 triled_src;
+	bool triled_has_atc_ctl;
+	bool triled_has_src_sel;
+
+	unsigned int num_channels;
+	struct lpg_channel channels[] __counted_by(num_channels);
+};
+
 /**
  * struct lpg_channel_data - per channel initialization data
  * @sdam_offset:	Channel offset in LPG SDAM
@@ -1475,12 +1474,6 @@ static int lpg_init_channels(struct lpg *lpg)
 	struct lpg_channel *chan;
 	int i;
 
-	lpg->num_channels = data->num_channels;
-	lpg->channels = devm_kcalloc(lpg->dev, data->num_channels,
-				     sizeof(struct lpg_channel), GFP_KERNEL);
-	if (!lpg->channels)
-		return -ENOMEM;
-
 	for (i = 0; i < data->num_channels; i++) {
 		chan = &lpg->channels[i];
 
@@ -1603,18 +1596,20 @@ static int lpg_init_sdam(struct lpg *lpg)
 
 static int lpg_probe(struct platform_device *pdev)
 {
+	const struct lpg_data *data;
 	struct lpg *lpg;
 	int ret;
 	int i;
 
-	lpg = devm_kzalloc(&pdev->dev, sizeof(*lpg), GFP_KERNEL);
+	data = of_device_get_match_data(&pdev->dev);
+	if (!data)
+		return -EINVAL;
+
+	lpg = devm_kzalloc(&pdev->dev, struct_size(lpg, channels, data->num_channels), GFP_KERNEL);
 	if (!lpg)
 		return -ENOMEM;
 
-	lpg->data = of_device_get_match_data(&pdev->dev);
-	if (!lpg->data)
-		return -EINVAL;
-
+	lpg->num_channels = data->num_channels;
 	lpg->dev = &pdev->dev;
 	mutex_init(&lpg->lock);
 
-- 
2.53.0