linux-kernel - [PATCH 5.15 232/779] pwm: lpc18xx-sct: Simplify driver by not using pwm_[gs]et_chip

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Date:   Mon, 15 Aug 2022 19:57:56 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>,
        Thierry Reding <thierry.reding@...il.com>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.15 232/779] pwm: lpc18xx-sct: Simplify driver by not using pwm_[gs]et_chip_data()

From: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>

[ Upstream commit 9136a39e6cf69e49803ac6123a4ac4431bc915a2 ]

The per-channel data is available directly in the driver data struct. So
use it without making use of pwm_[gs]et_chip_data().

The relevant change introduced by this patch to lpc18xx_pwm_disable() at
the assembler level (for an arm lpc18xx_defconfig build) is:

	push    {r3, r4, r5, lr}
	mov     r4, r0
	mov     r0, r1
	mov     r5, r1
	bl      0 <pwm_get_chip_data>
	ldr     r3, [r0, #0]

changes to

	ldr     r3, [r1, #8]
	push    {r4, lr}
	add.w   r3, r0, r3, lsl #2
	ldr     r3, [r3, #92]   ; 0x5c

So this reduces stack usage, has an improved runtime behavior because of
better pipeline usage, doesn't branch to an external function and the
generated code is a bit smaller occupying less memory.

The codesize of lpc18xx_pwm_probe() is reduced by 32 bytes.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@...il.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/pwm/pwm-lpc18xx-sct.c | 23 ++++++-----------------
 1 file changed, 6 insertions(+), 17 deletions(-)

diff --git a/drivers/pwm/pwm-lpc18xx-sct.c b/drivers/pwm/pwm-lpc18xx-sct.c
index 6cf02554066c..b909096dba2f 100644
--- a/drivers/pwm/pwm-lpc18xx-sct.c
+++ b/drivers/pwm/pwm-lpc18xx-sct.c
@@ -166,7 +166,7 @@ static void lpc18xx_pwm_config_duty(struct pwm_chip *chip,
 				    struct pwm_device *pwm, int duty_ns)
 {
 	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
-	struct lpc18xx_pwm_data *lpc18xx_data = pwm_get_chip_data(pwm);
+	struct lpc18xx_pwm_data *lpc18xx_data = &lpc18xx_pwm->channeldata[pwm->hwpwm];
 	u64 val;
 
 	val = (u64)duty_ns * lpc18xx_pwm->clk_rate;
@@ -236,7 +236,7 @@ static int lpc18xx_pwm_set_polarity(struct pwm_chip *chip,
 static int lpc18xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
-	struct lpc18xx_pwm_data *lpc18xx_data = pwm_get_chip_data(pwm);
+	struct lpc18xx_pwm_data *lpc18xx_data = &lpc18xx_pwm->channeldata[pwm->hwpwm];
 	enum lpc18xx_pwm_res_action res_action;
 	unsigned int set_event, clear_event;
 
@@ -271,7 +271,7 @@ static int lpc18xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 static void lpc18xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
-	struct lpc18xx_pwm_data *lpc18xx_data = pwm_get_chip_data(pwm);
+	struct lpc18xx_pwm_data *lpc18xx_data = &lpc18xx_pwm->channeldata[pwm->hwpwm];
 
 	lpc18xx_pwm_writel(lpc18xx_pwm,
 			   LPC18XX_PWM_EVCTRL(lpc18xx_data->duty_event), 0);
@@ -282,7 +282,7 @@ static void lpc18xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 static int lpc18xx_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
-	struct lpc18xx_pwm_data *lpc18xx_data = pwm_get_chip_data(pwm);
+	struct lpc18xx_pwm_data *lpc18xx_data = &lpc18xx_pwm->channeldata[pwm->hwpwm];
 	unsigned long event;
 
 	event = find_first_zero_bit(&lpc18xx_pwm->event_map,
@@ -303,7 +303,7 @@ static int lpc18xx_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 static void lpc18xx_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
-	struct lpc18xx_pwm_data *lpc18xx_data = pwm_get_chip_data(pwm);
+	struct lpc18xx_pwm_data *lpc18xx_data = &lpc18xx_pwm->channeldata[pwm->hwpwm];
 
 	clear_bit(lpc18xx_data->duty_event, &lpc18xx_pwm->event_map);
 }
@@ -327,8 +327,7 @@ MODULE_DEVICE_TABLE(of, lpc18xx_pwm_of_match);
 static int lpc18xx_pwm_probe(struct platform_device *pdev)
 {
 	struct lpc18xx_pwm_chip *lpc18xx_pwm;
-	struct pwm_device *pwm;
-	int ret, i;
+	int ret;
 	u64 val;
 
 	lpc18xx_pwm = devm_kzalloc(&pdev->dev, sizeof(*lpc18xx_pwm),
@@ -398,16 +397,6 @@ static int lpc18xx_pwm_probe(struct platform_device *pdev)
 	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_LIMIT,
 			   BIT(lpc18xx_pwm->period_event));
 
-	for (i = 0; i < lpc18xx_pwm->chip.npwm; i++) {
-		struct lpc18xx_pwm_data *data;
-
-		pwm = &lpc18xx_pwm->chip.pwms[i];
-
-		data = &lpc18xx_pwm->channeldata[i];
-
-		pwm_set_chip_data(pwm, data);
-	}
-
 	val = lpc18xx_pwm_readl(lpc18xx_pwm, LPC18XX_PWM_CTRL);
 	val &= ~LPC18XX_PWM_BIDIR;
 	val &= ~LPC18XX_PWM_CTRL_HALT;
-- 
2.35.1