From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Cercueil Subject: Re: [PATCH v3 1/3] pwm: jz4740: Use clocks from TCU driver Date: Tue, 11 Feb 2020 12:04:49 -0300 Message-ID: <1581433489.3.1@crapouillou.net> References: <20191210152734.39588-1-paul@crapouillou.net> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Return-path: Received: from outils.crapouillou.net ([89.234.176.41]:52974 "EHLO crapouillou.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727111AbgBKPFI (ORCPT ); Tue, 11 Feb 2020 10:05:08 -0500 In-Reply-To: <20191210152734.39588-1-paul@crapouillou.net> Sender: linux-pwm-owner@vger.kernel.org List-Id: linux-pwm@vger.kernel.org To: Thierry Reding , Uwe =?iso-8859-1?q?Kleine-K=F6nig?= Cc: od@zcrc.me, linux-pwm@vger.kernel.org, linux-kernel@vger.kernel.org, Mathieu Malaterre , Artur Rojek Hi, Any feedback on this patchset? -Paul Le mar., d=E9c. 10, 2019 at 16:27, Paul Cercueil =20 a =E9crit : > The ingenic-timer "TCU" driver provides us with clocks, that can be > (un)gated, reparented or reclocked from devicetree, instead of having > these settings hardcoded in this driver. >=20 > Each PWM channel's clk pointer is stored in PWM chip data to keep > the code simple. The calls to arch-specific timer code is replaced=20 > with > standard clock API calls to start and stop each channel's clock. >=20 > While this driver is devicetree-compatible, it is never (as of now) > probed from devicetree, so this change does not introduce a ABI=20 > problem > with current devicetree files. >=20 > Signed-off-by: Paul Cercueil > Tested-by: Mathieu Malaterre > Tested-by: Artur Rojek > --- >=20 > Notes: > v2: This patch is now before the patch introducing regmap, so the=20 > code > has changed a bit. > v3: - Use %pe printf specifier to print error > - Update commit message > - Removed call to jz4740_timer_set_ctrl() in jz4740_pwm_free()=20 > which > was reseting the clock's parent. >=20 > drivers/pwm/Kconfig | 1 + > drivers/pwm/pwm-jz4740.c | 53=20 > +++++++++++++++++++++++++++++----------- > 2 files changed, 40 insertions(+), 14 deletions(-) >=20 > diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig > index bd21655c37a6..15d3816341f3 100644 > --- a/drivers/pwm/Kconfig > +++ b/drivers/pwm/Kconfig > @@ -225,6 +225,7 @@ config PWM_IMX_TPM > config PWM_JZ4740 > tristate "Ingenic JZ47xx PWM support" > depends on MACH_INGENIC > + depends on COMMON_CLK > help > Generic PWM framework driver for Ingenic JZ47xx based > machines. > diff --git a/drivers/pwm/pwm-jz4740.c b/drivers/pwm/pwm-jz4740.c > index 9d78cc21cb12..ee50ac5fabb6 100644 > --- a/drivers/pwm/pwm-jz4740.c > +++ b/drivers/pwm/pwm-jz4740.c > @@ -24,7 +24,6 @@ >=20 > struct jz4740_pwm_chip { > struct pwm_chip chip; > - struct clk *clk; > }; >=20 > static inline struct jz4740_pwm_chip *to_jz4740(struct pwm_chip=20 > *chip) > @@ -34,6 +33,11 @@ static inline struct jz4740_pwm_chip=20 > *to_jz4740(struct pwm_chip *chip) >=20 > static int jz4740_pwm_request(struct pwm_chip *chip, struct=20 > pwm_device *pwm) > { > + struct jz4740_pwm_chip *jz =3D to_jz4740(chip); > + struct clk *clk; > + char clk_name[16]; > + int ret; > + > /* > * Timers 0 and 1 are used for system tasks, so they are unavailable > * for use as PWMs. > @@ -41,16 +45,32 @@ static int jz4740_pwm_request(struct pwm_chip=20 > *chip, struct pwm_device *pwm) > if (pwm->hwpwm < 2) > return -EBUSY; >=20 > - jz4740_timer_start(pwm->hwpwm); > + snprintf(clk_name, sizeof(clk_name), "timer%u", pwm->hwpwm); > + > + clk =3D clk_get(chip->dev, clk_name); > + if (IS_ERR(clk)) { > + if (PTR_ERR(clk) !=3D -EPROBE_DEFER) > + dev_err(chip->dev, "Failed to get clock: %pe", clk); > + return PTR_ERR(clk); > + } > + > + ret =3D clk_prepare_enable(clk); > + if (ret) { > + clk_put(clk); > + return ret; > + } > + > + pwm_set_chip_data(pwm, clk); >=20 > return 0; > } >=20 > static void jz4740_pwm_free(struct pwm_chip *chip, struct pwm_device=20 > *pwm) > { > - jz4740_timer_set_ctrl(pwm->hwpwm, 0); > + struct clk *clk =3D pwm_get_chip_data(pwm); >=20 > - jz4740_timer_stop(pwm->hwpwm); > + clk_disable_unprepare(clk); > + clk_put(clk); > } >=20 > static int jz4740_pwm_enable(struct pwm_chip *chip, struct=20 > pwm_device *pwm) > @@ -91,17 +111,22 @@ static int jz4740_pwm_apply(struct pwm_chip=20 > *chip, struct pwm_device *pwm, > const struct pwm_state *state) > { > struct jz4740_pwm_chip *jz4740 =3D to_jz4740(pwm->chip); > + struct clk *clk =3D pwm_get_chip_data(pwm), > + *parent_clk =3D clk_get_parent(clk); > + unsigned long rate, period, duty; > unsigned long long tmp; > - unsigned long period, duty; > unsigned int prescaler =3D 0; > uint16_t ctrl; > + int err; >=20 > - tmp =3D (unsigned long long)clk_get_rate(jz4740->clk) * state->period; > + rate =3D clk_get_rate(parent_clk); > + tmp =3D (unsigned long long)rate * state->period; > do_div(tmp, 1000000000); > period =3D tmp; >=20 > while (period > 0xffff && prescaler < 6) { > period >>=3D 2; > + rate >>=3D 2; > ++prescaler; > } >=20 > @@ -117,14 +142,18 @@ static int jz4740_pwm_apply(struct pwm_chip=20 > *chip, struct pwm_device *pwm, >=20 > jz4740_pwm_disable(chip, pwm); >=20 > + err =3D clk_set_rate(clk, rate); > + if (err) { > + dev_err(chip->dev, "Unable to set rate: %d", err); > + return err; > + } > + > jz4740_timer_set_count(pwm->hwpwm, 0); > jz4740_timer_set_duty(pwm->hwpwm, duty); > jz4740_timer_set_period(pwm->hwpwm, period); >=20 > - ctrl =3D JZ_TIMER_CTRL_PRESCALER(prescaler) | JZ_TIMER_CTRL_SRC_EXT | > - JZ_TIMER_CTRL_PWM_ABBRUPT_SHUTDOWN; > - > - jz4740_timer_set_ctrl(pwm->hwpwm, ctrl); > + ctrl =3D jz4740_timer_get_ctrl(pwm->hwpwm); > + ctrl |=3D JZ_TIMER_CTRL_PWM_ABBRUPT_SHUTDOWN; >=20 > switch (state->polarity) { > case PWM_POLARITY_NORMAL: > @@ -158,10 +187,6 @@ static int jz4740_pwm_probe(struct=20 > platform_device *pdev) > if (!jz4740) > return -ENOMEM; >=20 > - jz4740->clk =3D devm_clk_get(&pdev->dev, "ext"); > - if (IS_ERR(jz4740->clk)) > - return PTR_ERR(jz4740->clk); > - > jz4740->chip.dev =3D &pdev->dev; > jz4740->chip.ops =3D &jz4740_pwm_ops; > jz4740->chip.npwm =3D NUM_PWM; > -- > 2.24.0 >=20 =