From: Alexandre Belloni <alexandre.belloni@free-electrons.com>
To: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Thierry Reding <thierry.reding@gmail.com>,
linux-pwm@vger.kernel.org,
Mike Turquette <mturquette@baylibre.com>,
Stephen Boyd <sboyd@codeaurora.org>,
linux-clk@vger.kernel.org, Mark Brown <broonie@kernel.org>,
Liam Girdwood <lgirdwood@gmail.com>,
Kamil Debski <k.debski@samsung.com>,
lm-sensors@lm-sensors.org, Jean Delvare <jdelvare@suse.com>,
Guenter Roeck <linux@roeck-us.net>,
Dmitry Torokhov <dmitry.torokhov@gmail.com>,
linux-input@vger.kernel.org, Bryan Wu <cooloney@gmail.com>,
Richard Purdie <rpurdie@rpsys.net>,
Jacek Anaszewski <j.anaszewski@samsung.com>,
linux-leds@vger.kernel.org,
Maxime Ripard <maxime.ripard@free-electrons.com>,
Chen-Yu Tsai <wens@csie.org>,
linux-sunxi@googlegroups.com,
Joachim Eastwood <manabian@gmail.com>,
Thomas Petazzoni <thomas.petazzoni@free-electrons.com>,
Heiko Stuebner <heiko@sntech.de>,
linux-rockchip@lists.infradead.org,
Jingoo Han <jingoohan1@gmail.com>,
Lee Jones <lee.jones@linaro.org>,
linux-fbdev@vger.kernel.org,
Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>,
Tomi Valkeinen <tomi.valkeinen@ti.com>,
Robert Jarzmik <robert.jarzmik@free.fr>,
Kukjin Kim <kgene@kernel.org>,
Krzysztof Kozlowski <k.kozlowski@samsung.com>,
linux-samsung-soc@vger.kernel.org,
intel-gfx@lists.freedesktop.org,
Daniel Vetter <daniel.vetter@intel.com>,
Jani Nikula <jani.nikula@linux.intel.com>,
Jonathan Corbet <corbet@lwn.net>,
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Hartley Sweeten <hsweeten@visionengravers.com>,
Ryan Mallon <rmallon@gmail.com>,
Alexander Shiyan <shc_work@mail.ru>, Milo Kim <milo.kim@ti.com>
Subject: Re: [PATCH v5 26/46] pwm: sun4i: implement hardware readout
Date: Thu, 31 Mar 2016 10:00:33 +0200 [thread overview]
Message-ID: <20160331080033.GR2346@piout.net> (raw)
In-Reply-To: <1459368249-13241-27-git-send-email-boris.brezillon@free-electrons.com>
On 30/03/2016 at 22:03:49 +0200, Boris Brezillon wrote :
> Implement ->get_state() instead of only initializing the polarity in
> the probe function.
>
> This implementation also takes care of keeping the PWM clk enabled if at
> least one of the PWM exported by the PWM chip is already enabled, which
> should prevent glitches.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> ---
> drivers/pwm/pwm-sun4i.c | 74 ++++++++++++++++++++++++++++++++++++-------------
> 1 file changed, 55 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c
> index 03a99a5..34cb296 100644
> --- a/drivers/pwm/pwm-sun4i.c
> +++ b/drivers/pwm/pwm-sun4i.c
> @@ -252,11 +252,65 @@ static void sun4i_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
> clk_disable_unprepare(sun4i_pwm->clk);
> }
>
> +static void sun4i_pwm_get_state(struct pwm_chip *chip,
> + struct pwm_device *pwm,
> + struct pwm_state *pstate)
> +{
> + struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
> + unsigned int clk_rate = clk_get_rate(sun4i_pwm->clk);
> + int prescaler, prescalerid;
> + int ret;
> + u32 val;
> +
> + ret = clk_prepare_enable(sun4i_pwm->clk);
> + if (ret) {
> + dev_err(chip->dev, "Failed to enable PWM clock");
> + return;
> + }
> +
> + val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG);
> + if (val & BIT_CH(PWM_ACT_STATE, pwm->hwpwm))
> + pstate->polarity = PWM_POLARITY_INVERSED;
> + else
> + pstate->polarity = PWM_POLARITY_NORMAL;
> +
> + if ((val & BIT_CH(PWM_EN, pwm->hwpwm)) &&
> + (val & BIT_CH(PWM_CLK_GATING, pwm->hwpwm)))
> + pstate->enabled = true;
> + else
> + pstate->enabled = false;
> +
> + pstate->period = 0;
> + pstate->duty_cycle = 0;
> + prescalerid = (val >> (PWMCH_OFFSET * pwm->hwpwm)) & PWM_PRESCAL_MASK;
> + prescaler = prescaler_table[prescalerid];
> + if (prescaler) {
> + u64 timens;
> +
> + clk_rate /= prescaler;
> +
> + val = sun4i_pwm_readl(sun4i_pwm, PWM_CH_PRD(pwm->hwpwm));
> +
> + timens = ((val >> 16) & PWM_PRD_MASK) + 1;
> + timens *= NSEC_PER_SEC;
> + do_div(timens, clk_rate);
> + pstate->period = timens;
> +
> + timens = val & PWM_DTY_MASK;
> + timens *= NSEC_PER_SEC;
> + do_div(timens, clk_rate);
> + pstate->duty_cycle = timens;
> + }
> +
> + clk_disable_unprepare(sun4i_pwm->clk);
> +}
> +
> static const struct pwm_ops sun4i_pwm_ops = {
> .config = sun4i_pwm_config,
> .set_polarity = sun4i_pwm_set_polarity,
> .enable = sun4i_pwm_enable,
> .disable = sun4i_pwm_disable,
> + .get_state = sun4i_pwm_get_state,
> .owner = THIS_MODULE,
> };
>
> @@ -307,8 +361,7 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
> {
> struct sun4i_pwm_chip *pwm;
> struct resource *res;
> - u32 val;
> - int i, ret;
> + int ret;
> const struct of_device_id *match;
>
> match = of_match_device(sun4i_pwm_dt_ids, &pdev->dev);
> @@ -345,24 +398,7 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
>
> platform_set_drvdata(pdev, pwm);
>
> - ret = clk_prepare_enable(pwm->clk);
> - if (ret) {
> - dev_err(&pdev->dev, "failed to enable PWM clock\n");
> - goto clk_error;
> - }
> -
> - val = sun4i_pwm_readl(pwm, PWM_CTRL_REG);
> - for (i = 0; i < pwm->chip.npwm; i++)
> - if (!(val & BIT_CH(PWM_ACT_STATE, i)))
> - pwm_set_polarity(&pwm->chip.pwms[i],
> - PWM_POLARITY_INVERSED);
> - clk_disable_unprepare(pwm->clk);
> -
> return 0;
> -
> -clk_error:
> - pwmchip_remove(&pwm->chip);
> - return ret;
> }
>
> static int sun4i_pwm_remove(struct platform_device *pdev)
> --
> 2.5.0
>
--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
next prev parent reply other threads:[~2016-03-31 8:00 UTC|newest]
Thread overview: 105+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-30 20:03 [PATCH v5 00/46] pwm: add support for atomic update Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 01/46] pwm: rcar: make use of pwm_is_enabled() Boris Brezillon
2016-04-12 11:01 ` Thierry Reding
2016-04-14 11:05 ` Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 02/46] backlight: pwm_bl: remove useless call to pwm_set_period() Boris Brezillon
2016-04-12 11:03 ` Thierry Reding
2016-04-12 14:16 ` Lee Jones
2016-04-12 14:25 ` Thierry Reding
2016-03-30 20:03 ` [PATCH v5 03/46] backlight: lm3630a_bl: stop messing with the pwm->period field Boris Brezillon
2016-04-12 11:08 ` Thierry Reding
2016-04-12 14:16 ` Lee Jones
2016-04-12 14:26 ` Thierry Reding
2016-04-13 8:25 ` Lee Jones
2016-04-13 8:26 ` Lee Jones
2016-03-30 20:03 ` [PATCH v5 04/46] pwm: get rid of pwm->lock Boris Brezillon
2016-04-12 11:22 ` Thierry Reding
2016-04-12 11:32 ` Boris Brezillon
2016-04-12 11:46 ` Thierry Reding
2016-03-30 20:03 ` [PATCH v5 05/46] pwm: introduce the pwm_args concept Boris Brezillon
2016-03-30 21:55 ` Stephen Boyd
2016-03-31 7:09 ` Boris Brezillon
2016-03-31 7:57 ` Boris Brezillon
2016-04-12 11:39 ` Thierry Reding
2016-04-12 12:04 ` Boris Brezillon
2016-04-12 12:20 ` Thierry Reding
2016-04-12 12:55 ` Boris Brezillon
2016-04-12 13:06 ` Boris Brezillon
2016-04-12 13:15 ` Thierry Reding
2016-03-30 20:03 ` [PATCH v5 06/46] pwm: use pwm_get/set_xxx() helpers where appropriate Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 07/46] clk: pwm: use pwm_get_args() " Boris Brezillon
2016-03-30 21:58 ` Stephen Boyd
2016-03-30 20:03 ` [PATCH v5 08/46] hwmon: pwm-fan: " Boris Brezillon
2016-03-30 22:52 ` Guenter Roeck
2016-03-31 7:07 ` Boris Brezillon
2016-04-04 15:20 ` Thierry Reding
2016-04-01 8:29 ` Kamil Debski
2016-03-30 20:03 ` [PATCH v5 09/46] misc: max77693-haptic: " Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 10/46] leds: pwm: " Boris Brezillon
2016-03-31 7:13 ` Jacek Anaszewski
2016-03-30 20:03 ` [PATCH v5 11/46] regulator: " Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 12/46] fbdev: ssd1307fb: " Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 13/46] backlight: pwm_bl: " Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 14/46] pwm: keep PWM state in sync with hardware state Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 15/46] pwm: introduce the pwm_state concept Boris Brezillon
2016-04-12 11:49 ` Thierry Reding
2016-04-12 12:17 ` Boris Brezillon
2016-04-12 12:21 ` Thierry Reding
2016-04-12 12:45 ` Boris Brezillon
2016-04-12 13:11 ` Thierry Reding
2016-04-12 13:26 ` Boris Brezillon
2016-04-12 14:05 ` Thierry Reding
2016-04-12 14:13 ` Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 16/46] pwm: move the enabled/disabled info into pwm_state Boris Brezillon
2016-04-12 11:51 ` Thierry Reding
2016-03-30 20:03 ` [PATCH v5 17/46] pwm: add the PWM initial state retrieval infra Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 18/46] pwm: add the core infrastructure to allow atomic update Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 19/46] pwm: switch to the atomic API Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 20/46] pwm: add information about polarity, duty cycle and period to debugfs Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 21/46] pwm: rockchip: add initial state retrieval Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 22/46] pwm: rockchip: avoid glitches on already running PWMs Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 23/46] pwm: rockchip: add support for atomic update Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 24/46] pwm: sti: add support for initial state retrieval Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 25/46] pwm: sti: avoid glitches on already running PWMs Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 26/46] pwm: sun4i: implement hardware readout Boris Brezillon
2016-03-31 8:00 ` Alexandre Belloni [this message]
2016-03-30 20:03 ` [PATCH v5 27/46] regulator: pwm: adjust PWM config at probe time Boris Brezillon
2016-03-30 21:22 ` Mark Brown
2016-03-30 20:03 ` [PATCH v5 28/46] regulator: pwm: swith to the atomic PWM API Boris Brezillon
2016-03-30 21:23 ` Mark Brown
2016-03-30 20:03 ` [PATCH v5 29/46] regulator: pwm: properly initialize the ->state field Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 30/46] regulator: pwm: retrieve correct voltage Boris Brezillon
2016-03-30 21:24 ` Mark Brown
2016-04-07 21:54 ` Boris Brezillon
2016-04-12 4:42 ` Mark Brown
2016-04-12 8:37 ` Boris Brezillon
2016-04-12 10:09 ` Mark Brown
2016-04-12 10:31 ` Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 31/46] pwm: update documentation Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 32/46] pwm: deprecate pwm_config(), pwm_enable() and pwm_disable() Boris Brezillon
2016-03-31 17:38 ` Dmitry Torokhov
2016-03-31 18:54 ` Boris Brezillon
2016-04-04 15:22 ` Thierry Reding
2016-03-30 20:03 ` [PATCH v5 33/46] pwm: replace pwm_disable() by pwm_apply_state() Boris Brezillon
2016-03-30 20:03 ` [PATCH v5 34/46] clk: pwm: switch to the atomic API Boris Brezillon
2016-03-30 22:01 ` Stephen Boyd
2016-03-31 6:57 ` Boris Brezillon
2016-04-04 15:30 ` Thierry Reding
2016-03-30 20:03 ` [PATCH v5 35/46] hwmon: pwm-fan: " Boris Brezillon
2016-04-01 8:29 ` Kamil Debski
2016-03-30 20:03 ` [PATCH v5 36/46] input: misc: max77693: " Boris Brezillon
2016-03-31 17:48 ` Dmitry Torokhov
2016-03-31 18:57 ` Boris Brezillon
2016-04-04 15:34 ` Thierry Reding
2016-03-30 20:04 ` [PATCH v5 37/46] input: misc: max8997: switch to the atomic PWM API Boris Brezillon
2016-03-30 20:04 ` [PATCH v5 38/46] input: misc: pwm-beeper: " Boris Brezillon
2016-03-30 20:04 ` [PATCH v5 39/46] leds: pwm: " Boris Brezillon
2016-03-30 20:04 ` [PATCH v5 40/46] backlight: lm3630a: " Boris Brezillon
2016-03-30 20:04 ` [PATCH v5 41/46] backlight: lp855x: " Boris Brezillon
2016-03-30 20:04 ` [PATCH v5 42/46] backlight: lp8788: " Boris Brezillon
2016-03-30 20:04 ` [PATCH v5 43/46] backlight: pwm_bl: " Boris Brezillon
2016-03-30 20:04 ` [PATCH v5 44/46] video: ssd1307fb: " Boris Brezillon
2016-03-30 20:04 ` [PATCH v5 45/46] drm: i915: " Boris Brezillon
2016-03-30 20:04 ` [PATCH v5 46/46] ARM: s3c24xx: rx1950: " Boris Brezillon
2016-03-30 20:18 ` [PATCH v5 00/46] pwm: add support for atomic update Boris Brezillon
2016-04-11 22:42 ` Boris Brezillon
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