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    Subject[PATCH 5.15 232/779] pwm: lpc18xx-sct: Simplify driver by not using pwm_[gs]et_chip_data()
    Date
    From: Uwe Kleine-König <u.kleine-koenig@pengutronix.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@pengutronix.de>
    Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
    Signed-off-by: Sasha Levin <sashal@kernel.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


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