There is no semantic change, but it is a nicer on the eyes of a reader,
because
TIM_CCR1 + 4 * ch
encodes internal register knowledge, while
TIM_CCRx(ch + 1)
keeps that information completely in the header defining the registers.
While I expected this to not result in any changes in the binary, gcc 13
(as provided by Debian in the gcc-13-arm-linux-gnueabihf 13.2.0-12cross1
package) compiles the new version with an allmodconfig to more compact
code:
$ source/scripts/bloat-o-meter drivers/pwm/pwm-stm32.o-pre drivers/pwm/pwm-stm32.o
add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-488 (-488)
Function old new delta
stm32_pwm_get_state 968 936 -32
stm32_pwm_apply_locked 1920 1464 -456
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxx>
---
drivers/pwm/pwm-stm32.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c
index a2f231d13a9f..49a76514b83e 100644
--- a/drivers/pwm/pwm-stm32.c
+++ b/drivers/pwm/pwm-stm32.c
@@ -360,7 +360,7 @@ static int stm32_pwm_config(struct stm32_pwm *priv, unsigned int ch,
dty = mul_u64_u64_div_u64(duty_ns, clk_get_rate(priv->clk),
(u64)NSEC_PER_SEC * (prescaler + 1));
- regmap_write(priv->regmap, TIM_CCR1 + 4 * ch, dty);
+ regmap_write(priv->regmap, TIM_CCRx(ch + 1), dty);
/* Configure output mode */
shift = (ch & 0x1) * CCMR_CHANNEL_SHIFT;
@@ -382,9 +382,9 @@ static int stm32_pwm_set_polarity(struct stm32_pwm *priv, unsigned int ch,
{
u32 mask;
- mask = TIM_CCER_CC1P << (ch * 4);
+ mask = TIM_CCER_CCxP(ch + 1);
if (priv->have_complementary_output)
- mask |= TIM_CCER_CC1NP << (ch * 4);
+ mask |= TIM_CCER_CCxNP(ch + 1);
regmap_update_bits(priv->regmap, TIM_CCER, mask,
polarity == PWM_POLARITY_NORMAL ? 0 : mask);
@@ -402,9 +402,9 @@ static int stm32_pwm_enable(struct stm32_pwm *priv, unsigned int ch)
return ret;
/* Enable channel */
- mask = TIM_CCER_CC1E << (ch * 4);
+ mask = TIM_CCER_CCxE(ch + 1);
if (priv->have_complementary_output)
- mask |= TIM_CCER_CC1NE << (ch * 4);
+ mask |= TIM_CCER_CCxNE(ch);
regmap_set_bits(priv->regmap, TIM_CCER, mask);
@@ -422,9 +422,9 @@ static void stm32_pwm_disable(struct stm32_pwm *priv, unsigned int ch)
u32 mask;
/* Disable channel */
- mask = TIM_CCER_CC1E << (ch * 4);
+ mask = TIM_CCER_CCxE(ch + 1);
if (priv->have_complementary_output)
- mask |= TIM_CCER_CC1NE << (ch * 4);
+ mask |= TIM_CCER_CCxNE(ch + 1);
regmap_clear_bits(priv->regmap, TIM_CCER, mask);
@@ -493,8 +493,8 @@ static int stm32_pwm_get_state(struct pwm_chip *chip,
if (ret)
goto out;
- state->enabled = ccer & (TIM_CCER_CC1E << (ch * 4));
- state->polarity = (ccer & (TIM_CCER_CC1P << (ch * 4))) ?
+ state->enabled = ccer & TIM_CCER_CCxE(ch + 1);
+ state->polarity = (ccer & TIM_CCER_CCxP(ch + 1)) ?
PWM_POLARITY_INVERSED : PWM_POLARITY_NORMAL;
ret = regmap_read(priv->regmap, TIM_PSC, &psc);
if (ret)
@@ -502,7 +502,7 @@ static int stm32_pwm_get_state(struct pwm_chip *chip,
ret = regmap_read(priv->regmap, TIM_ARR, &arr);
if (ret)
goto out;
- ret = regmap_read(priv->regmap, TIM_CCR1 + 4 * ch, &ccr);
+ ret = regmap_read(priv->regmap, TIM_CCRx(ch + 1), &ccr);
if (ret)
goto out;
@@ -702,7 +702,7 @@ static int stm32_pwm_suspend(struct device *dev)
ccer = active_channels(priv);
for (i = 0; i < chip->npwm; i++) {
- mask = TIM_CCER_CC1E << (i * 4);
+ mask = TIM_CCER_CCxE(i + 1);
if (ccer & mask) {
dev_err(dev, "PWM %u still in use by consumer %s\n",
i, chip->pwms[i].label);
--
2.43.0
