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Message-ID: <pqnl66xnct5lqua36iasqws4kowhqtn6vkq7fml76pomcnatj4@q66n3siflgoc>
Date: Mon, 5 Feb 2024 18:12:59 +0100
From: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
To: Jerome Brunet <jbrunet@...libre.com>
Cc: Thierry Reding <thierry.reding@...il.com>,
Neil Armstrong <neil.armstrong@...aro.org>, Rob Herring <robh+dt@...nel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>, Conor Dooley <conor+dt@...nel.org>,
Kevin Hilman <khilman@...libre.com>, devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
linux-amlogic@...ts.infradead.org, linux-pwm@...r.kernel.org, JunYi Zhao <junyi.zhao@...ogic.com>
Subject: Re: [PATCH v4 4/6] pwm: meson: use device data to carry information
around
On Fri, Dec 22, 2023 at 12:16:52PM +0100, Jerome Brunet wrote:
> Use struct device data to carry the information data around, instead
> of embedded the pwm structure in it and using container_of()
>
> Doing so works just as well and makes it a little easier to add setup
> callback depending on the DT compatible.
>
> Signed-off-by: Jerome Brunet <jbrunet@...libre.com>
> ---
> drivers/pwm/pwm-meson.c | 39 +++++++++++++++++++++++----------------
> 1 file changed, 23 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c
> index ef50c337f444..15c44185d784 100644
> --- a/drivers/pwm/pwm-meson.c
> +++ b/drivers/pwm/pwm-meson.c
> @@ -101,7 +101,6 @@ struct meson_pwm_data {
> };
>
> struct meson_pwm {
> - struct pwm_chip chip;
> const struct meson_pwm_data *data;
> struct meson_pwm_channel channels[MESON_NUM_PWMS];
> void __iomem *base;
> @@ -114,7 +113,7 @@ struct meson_pwm {
>
> static inline struct meson_pwm *to_meson_pwm(struct pwm_chip *chip)
> {
> - return container_of(chip, struct meson_pwm, chip);
> + return dev_get_drvdata(chip->dev);
> }
>
> static int meson_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
> @@ -146,6 +145,7 @@ static int meson_pwm_calc(struct meson_pwm *meson, struct pwm_device *pwm,
> const struct pwm_state *state)
> {
> struct meson_pwm_channel *channel = &meson->channels[pwm->hwpwm];
> + struct device *dev = pwm->chip->dev;
> unsigned int cnt, duty_cnt;
> unsigned long fin_freq;
> u64 duty, period, freq;
> @@ -168,19 +168,19 @@ static int meson_pwm_calc(struct meson_pwm *meson, struct pwm_device *pwm,
>
> fin_freq = clk_round_rate(channel->clk, freq);
> if (fin_freq == 0) {
> - dev_err(meson->chip.dev, "invalid source clock frequency\n");
> + dev_err(dev, "invalid source clock frequency\n");
> return -EINVAL;
> }
>
> - dev_dbg(meson->chip.dev, "fin_freq: %lu Hz\n", fin_freq);
> + dev_dbg(dev, "fin_freq: %lu Hz\n", fin_freq);
>
> cnt = div_u64(fin_freq * period, NSEC_PER_SEC);
> if (cnt > 0xffff) {
> - dev_err(meson->chip.dev, "unable to get period cnt\n");
> + dev_err(dev, "unable to get period cnt\n");
> return -EINVAL;
> }
>
> - dev_dbg(meson->chip.dev, "period=%llu cnt=%u\n", period, cnt);
> + dev_dbg(dev, "period=%llu cnt=%u\n", period, cnt);
>
> if (duty == period) {
> channel->hi = cnt;
> @@ -191,7 +191,7 @@ static int meson_pwm_calc(struct meson_pwm *meson, struct pwm_device *pwm,
> } else {
> duty_cnt = div_u64(fin_freq * duty, NSEC_PER_SEC);
>
> - dev_dbg(meson->chip.dev, "duty=%llu duty_cnt=%u\n", duty, duty_cnt);
> + dev_dbg(dev, "duty=%llu duty_cnt=%u\n", duty, duty_cnt);
>
> channel->hi = duty_cnt;
> channel->lo = cnt - duty_cnt;
> @@ -214,7 +214,7 @@ static void meson_pwm_enable(struct meson_pwm *meson, struct pwm_device *pwm)
>
> err = clk_set_rate(channel->clk, channel->rate);
> if (err)
> - dev_err(meson->chip.dev, "setting clock rate failed\n");
> + dev_err(pwm->chip->dev, "setting clock rate failed\n");
>
> spin_lock_irqsave(&meson->lock, flags);
>
> @@ -425,10 +425,10 @@ static const struct of_device_id meson_pwm_matches[] = {
> };
> MODULE_DEVICE_TABLE(of, meson_pwm_matches);
>
> -static int meson_pwm_init_channels(struct meson_pwm *meson)
> +static int meson_pwm_init_channels(struct device *dev)
> {
> struct clk_parent_data mux_parent_data[MESON_NUM_MUX_PARENTS] = {};
> - struct device *dev = meson->chip.dev;
> + struct meson_pwm *meson = dev_get_drvdata(dev);
> unsigned int i;
> char name[255];
> int err;
> @@ -438,7 +438,7 @@ static int meson_pwm_init_channels(struct meson_pwm *meson)
> mux_parent_data[i].name = meson->data->parent_names[i];
> }
>
> - for (i = 0; i < meson->chip.npwm; i++) {
> + for (i = 0; i < MESON_NUM_PWMS; i++) {
> struct meson_pwm_channel *channel = &meson->channels[i];
> struct clk_parent_data div_parent = {}, gate_parent = {};
> struct clk_init_data init = {};
> @@ -519,28 +519,35 @@ static int meson_pwm_init_channels(struct meson_pwm *meson)
> static int meson_pwm_probe(struct platform_device *pdev)
> {
> struct meson_pwm *meson;
> + struct pwm_chip *chip;
> int err;
>
> + chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
> + if (!chip)
> + return -ENOMEM;
> +
> meson = devm_kzalloc(&pdev->dev, sizeof(*meson), GFP_KERNEL);
> if (!meson)
> return -ENOMEM;
>
> + platform_set_drvdata(pdev, meson);
> +
> meson->base = devm_platform_ioremap_resource(pdev, 0);
> if (IS_ERR(meson->base))
> return PTR_ERR(meson->base);
>
> spin_lock_init(&meson->lock);
> - meson->chip.dev = &pdev->dev;
> - meson->chip.ops = &meson_pwm_ops;
> - meson->chip.npwm = MESON_NUM_PWMS;
> + chip->dev = &pdev->dev;
> + chip->ops = &meson_pwm_ops;
> + chip->npwm = MESON_NUM_PWMS;
>
> meson->data = of_device_get_match_data(&pdev->dev);
>
> - err = meson_pwm_init_channels(meson);
> + err = meson_pwm_init_channels(&pdev->dev);
> if (err < 0)
> return err;
>
> - err = devm_pwmchip_add(&pdev->dev, &meson->chip);
> + err = devm_pwmchip_add(&pdev->dev, chip);
> if (err < 0)
> return dev_err_probe(&pdev->dev, err,
> "failed to register PWM chip\n");
Parts of this change overlap with plans I have for this driver. I
reworked the series a bit now, also affecting the meson driver, the
previous submission is available at https://lore.kernel.org/linux-pwm/bf6f7c6253041f60ee8f35b5c9c9e8d595332fb0.1706182805.git.u.kleine-koenig@pengutronix.de
I don't see the nice benefit of this patch yet, but I assume this will
become clearer when I check the next patch.
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
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