pwm: renesas: Drop usage of pwm_[gs]et_chip_data()

Instead of distributing the driver's bookkeeping over 5 (i.e.
TPU_CHANNEL_MAX + 1) separately allocated memory chunks, put all together
in struct tpu_device. This reduces the number of memory allocations and
so fragmentation and maybe even the number of cache misses. Also
&tpu->tpd[pwm->hwpwm] is cheaper to evaluate than pwm_get_chip_data(pwm)
as the former is just an addition in machine code while the latter involves
a function call.

Link: https://lore.kernel.org/r/20230705080650.2353391-6-u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-renesas-tpu.c

@@ -85,6 +85,7 @@ struct tpu_device {
 
 	void __iomem *base;
 	struct clk *clk;
+	struct tpu_pwm_device tpd[TPU_CHANNEL_MAX];
 };
 
 #define to_tpu_device(c)	container_of(c, struct tpu_device, chip)
@@ -215,9 +216,7 @@ static int tpu_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 	if (pwm->hwpwm >= TPU_CHANNEL_MAX)
 		return -EINVAL;
 
-	tpd = kzalloc(sizeof(*tpd), GFP_KERNEL);
-	if (tpd == NULL)
-		return -ENOMEM;
+	tpd = &tpu->tpd[pwm->hwpwm];
 
 	tpd->tpu = tpu;
 	tpd->channel = pwm->hwpwm;
@@ -228,24 +227,22 @@ static int tpu_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 
 	tpd->timer_on = false;
 
-	pwm_set_chip_data(pwm, tpd);
-
 	return 0;
 }
 
 static void tpu_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 {
-	struct tpu_pwm_device *tpd = pwm_get_chip_data(pwm);
+	struct tpu_device *tpu = to_tpu_device(chip);
+	struct tpu_pwm_device *tpd = &tpu->tpd[pwm->hwpwm];
 
 	tpu_pwm_timer_stop(tpd);
-	kfree(tpd);
 }
 
 static int tpu_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 			  u64 duty_ns, u64 period_ns, bool enabled)
 {
-	struct tpu_pwm_device *tpd = pwm_get_chip_data(pwm);
 	struct tpu_device *tpu = to_tpu_device(chip);
+	struct tpu_pwm_device *tpd = &tpu->tpd[pwm->hwpwm];
 	unsigned int prescaler;
 	bool duty_only = false;
 	u32 clk_rate;
@@ -353,7 +350,8 @@ static int tpu_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 static int tpu_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
 				enum pwm_polarity polarity)
 {
-	struct tpu_pwm_device *tpd = pwm_get_chip_data(pwm);
+	struct tpu_device *tpu = to_tpu_device(chip);
+	struct tpu_pwm_device *tpd = &tpu->tpd[pwm->hwpwm];
 
 	tpd->polarity = polarity;
 
@@ -362,7 +360,8 @@ static int tpu_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
 
 static int tpu_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
-	struct tpu_pwm_device *tpd = pwm_get_chip_data(pwm);
+	struct tpu_device *tpu = to_tpu_device(chip);
+	struct tpu_pwm_device *tpd = &tpu->tpd[pwm->hwpwm];
 	int ret;
 
 	ret = tpu_pwm_timer_start(tpd);
@@ -384,7 +383,8 @@ static int tpu_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 
 static void tpu_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
-	struct tpu_pwm_device *tpd = pwm_get_chip_data(pwm);
+	struct tpu_device *tpu = to_tpu_device(chip);
+	struct tpu_pwm_device *tpd = &tpu->tpd[pwm->hwpwm];
 
 	/* The timer must be running to modify the pin output configuration. */
 	tpu_pwm_timer_start(tpd);