[PATCH 7/8] counter: stm32-timer-cnt: Use container_of instead of struct counter_device::priv

["Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>]

Using counter->priv is a memory read and so more expensive than
container_of which is only an addition. (In this case even a noop
because the offset is 0.)

So container_of is expected to be a tad faster, it's type-safe, and
produces smaller code (ARCH=arm allmodconfig):

	add/remove: 0/0 grow/shrink: 0/11 up/down: 0/-132 (-132)
	Function                                     old     new   delta
	stm32_timer_cnt_probe                        436     424     -12
	stm32_count_write                            312     300     -12
	stm32_count_read                             236     224     -12
	stm32_count_function_write                   492     480     -12
	stm32_count_function_read                    396     384     -12
	stm32_count_enable_write                     488     476     -12
	stm32_count_enable_read                      236     224     -12
	stm32_count_direction_read                   240     228     -12
	stm32_count_ceiling_write                    200     188     -12
	stm32_count_ceiling_read                     236     224     -12
	stm32_action_read                            492     480     -12
	Total: Before=5504, After=5372, chg -2.40%

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/counter/stm32-timer-cnt.c | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c
index 0546e932db0c..ac0bea6ce690 100644
--- a/drivers/counter/stm32-timer-cnt.c
+++ b/drivers/counter/stm32-timer-cnt.c
@@ -37,6 +37,11 @@ struct stm32_timer_cnt {
 	struct stm32_timer_regs bak;
 };
 
+static inline struct stm32_timer_cnt *stm32_count_from_counter(struct counter_device *counter)
+{
+	return container_of(counter, struct stm32_timer_cnt, counter);
+}
+
 static const enum counter_function stm32_count_functions[] = {
 	COUNTER_FUNCTION_INCREASE,
 	COUNTER_FUNCTION_QUADRATURE_X2_A,
@@ -47,7 +52,7 @@ static const enum counter_function stm32_count_functions[] = {
 static int stm32_count_read(struct counter_device *counter,
 			    struct counter_count *count, u64 *val)
 {
-	struct stm32_timer_cnt *const priv = counter->priv;
+	struct stm32_timer_cnt *const priv = stm32_count_from_counter(counter);
 	u32 cnt;
 
 	regmap_read(priv->regmap, TIM_CNT, &cnt);
@@ -59,7 +64,7 @@ static int stm32_count_read(struct counter_device *counter,
 static int stm32_count_write(struct counter_device *counter,
 			     struct counter_count *count, const u64 val)
 {
-	struct stm32_timer_cnt *const priv = counter->priv;
+	struct stm32_timer_cnt *const priv = stm32_count_from_counter(counter);
 	u32 ceiling;
 
 	regmap_read(priv->regmap, TIM_ARR, &ceiling);
@@ -73,7 +78,7 @@ static int stm32_count_function_read(struct counter_device *counter,
 				     struct counter_count *count,
 				     enum counter_function *function)
 {
-	struct stm32_timer_cnt *const priv = counter->priv;
+	struct stm32_timer_cnt *const priv = stm32_count_from_counter(counter);
 	u32 smcr;
 
 	regmap_read(priv->regmap, TIM_SMCR, &smcr);
@@ -100,7 +105,7 @@ static int stm32_count_function_write(struct counter_device *counter,
 				      struct counter_count *count,
 				      enum counter_function function)
 {
-	struct stm32_timer_cnt *const priv = counter->priv;
+	struct stm32_timer_cnt *const priv = stm32_count_from_counter(counter);
 	u32 cr1, sms;
 
 	switch (function) {
@@ -140,7 +145,7 @@ static int stm32_count_direction_read(struct counter_device *counter,
 				      struct counter_count *count,
 				      enum counter_count_direction *direction)
 {
-	struct stm32_timer_cnt *const priv = counter->priv;
+	struct stm32_timer_cnt *const priv = stm32_count_from_counter(counter);
 	u32 cr1;
 
 	regmap_read(priv->regmap, TIM_CR1, &cr1);
@@ -153,7 +158,7 @@ static int stm32_count_direction_read(struct counter_device *counter,
 static int stm32_count_ceiling_read(struct counter_device *counter,
 				    struct counter_count *count, u64 *ceiling)
 {
-	struct stm32_timer_cnt *const priv = counter->priv;
+	struct stm32_timer_cnt *const priv = stm32_count_from_counter(counter);
 	u32 arr;
 
 	regmap_read(priv->regmap, TIM_ARR, &arr);
@@ -166,7 +171,7 @@ static int stm32_count_ceiling_read(struct counter_device *counter,
 static int stm32_count_ceiling_write(struct counter_device *counter,
 				     struct counter_count *count, u64 ceiling)
 {
-	struct stm32_timer_cnt *const priv = counter->priv;
+	struct stm32_timer_cnt *const priv = stm32_count_from_counter(counter);
 
 	if (ceiling > priv->max_arr)
 		return -ERANGE;
@@ -181,7 +186,7 @@ static int stm32_count_ceiling_write(struct counter_device *counter,
 static int stm32_count_enable_read(struct counter_device *counter,
 				   struct counter_count *count, u8 *enable)
 {
-	struct stm32_timer_cnt *const priv = counter->priv;
+	struct stm32_timer_cnt *const priv = stm32_count_from_counter(counter);
 	u32 cr1;
 
 	regmap_read(priv->regmap, TIM_CR1, &cr1);
@@ -194,7 +199,7 @@ static int stm32_count_enable_read(struct counter_device *counter,
 static int stm32_count_enable_write(struct counter_device *counter,
 				    struct counter_count *count, u8 enable)
 {
-	struct stm32_timer_cnt *const priv = counter->priv;
+	struct stm32_timer_cnt *const priv = stm32_count_from_counter(counter);
 	u32 cr1;
 
 	if (enable) {
@@ -336,7 +341,6 @@ static int stm32_timer_cnt_probe(struct platform_device *pdev)
 	priv->counter.num_counts = 1;
 	priv->counter.signals = stm32_signals;
 	priv->counter.num_signals = ARRAY_SIZE(stm32_signals);
-	priv->counter.priv = priv;
 
 	platform_set_drvdata(pdev, priv);
 
-- 
2.33.0