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pwm: lpc18xx-sct: Simplify driver by not using pwm_[gs]et_chip_data() 

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@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
This commit is contained in:
Uwe Kleine-König 2021-11-10 09:49:50 +01:00 committed by Thierry Reding
parent 20d9de9c4d
commit 9136a39e6c
1 changed files with 6 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
drivers/pwm/pwm-lpc18xx-sct.c
View File

@ -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;