From: Neil Armstrong <narmstrong@baylibre.com>
To: Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
linux-amlogic@lists.infradead.org, linux-pwm@vger.kernel.org,
thierry.reding@gmail.com, u.kleine-koenig@pengutronix.de
Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 03/14] pwm: meson: use GENMASK and FIELD_PREP for the lo and hi values
Date: Mon, 27 May 2019 14:25:44 +0200 [thread overview]
Message-ID: <b8e06a75-43a8-78f9-b475-61106906ac3e@baylibre.com> (raw)
In-Reply-To: <20190525181133.4875-4-martin.blumenstingl@googlemail.com>
On 25/05/2019 20:11, Martin Blumenstingl wrote:
> meson_pwm_calc() ensures that "lo" is always less than 16 bits wide
> (otherwise it would overflow into the "hi" part of the REG_PWM_{A,B}
> register).
> Use GENMASK and FIELD_PREP for the lo and hi values to make it easier to
> spot how wide these are internally. Additionally this is a preparation
> step for the .get_state() implementation where the GENMASK() for lo and
> hi becomes handy because it can be used with FIELD_GET() to extract the
> values from the register REG_PWM_{A,B} register.
>
> No functional changes intended.
>
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> ---
> drivers/pwm/pwm-meson.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c
> index 35b38c7201c3..c62a3ac924d0 100644
> --- a/drivers/pwm/pwm-meson.c
> +++ b/drivers/pwm/pwm-meson.c
> @@ -5,6 +5,8 @@
> * Copyright (C) 2014 Amlogic, Inc.
> */
>
> +#include <linux/bitfield.h>
> +#include <linux/bits.h>
> #include <linux/clk.h>
> #include <linux/clk-provider.h>
> #include <linux/err.h>
> @@ -20,7 +22,8 @@
>
> #define REG_PWM_A 0x0
> #define REG_PWM_B 0x4
> -#define PWM_HIGH_SHIFT 16
> +#define PWM_LOW_MASK GENMASK(15, 0)
> +#define PWM_HIGH_MASK GENMASK(31, 16)
>
> #define REG_MISC_AB 0x8
> #define MISC_B_CLK_EN BIT(23)
> @@ -217,7 +220,8 @@ static void meson_pwm_enable(struct meson_pwm *meson, struct pwm_device *pwm)
> value |= clk_enable;
> writel(value, meson->base + REG_MISC_AB);
>
> - value = (channel->hi << PWM_HIGH_SHIFT) | channel->lo;
> + value = FIELD_PREP(PWM_HIGH_MASK, channel->hi) |
> + FIELD_PREP(PWM_LOW_MASK, channel->lo);
> writel(value, meson->base + offset);
>
> value = readl(meson->base + REG_MISC_AB);
>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
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next prev parent reply other threads:[~2019-05-27 12:26 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-25 18:11 [PATCH 00/14] pwm-meson: cleanups and improvements Martin Blumenstingl
2019-05-25 18:11 ` [PATCH 01/14] pwm: meson: unify the parameter list of meson_pwm_{enable, disable} Martin Blumenstingl
2019-05-27 12:25 ` Neil Armstrong
2019-05-25 18:11 ` [PATCH 02/14] pwm: meson: use devm_clk_get_optional() to get the input clock Martin Blumenstingl
2019-05-27 12:25 ` Neil Armstrong
2019-05-25 18:11 ` [PATCH 03/14] pwm: meson: use GENMASK and FIELD_PREP for the lo and hi values Martin Blumenstingl
2019-05-27 12:25 ` Neil Armstrong [this message]
2019-05-25 18:11 ` [PATCH 04/14] pwm: meson: change MISC_CLK_SEL_WIDTH to MISC_CLK_SEL_MASK Martin Blumenstingl
2019-05-27 12:26 ` Neil Armstrong
2019-05-27 17:46 ` Martin Blumenstingl
2019-05-27 18:00 ` Uwe Kleine-König
2019-05-28 18:04 ` Martin Blumenstingl
2019-05-25 18:11 ` [PATCH 05/14] pwm: meson: don't duplicate the polarity internally Martin Blumenstingl
2019-05-27 12:26 ` Neil Armstrong
2019-05-25 18:11 ` [PATCH 06/14] pwm: meson: pass struct pwm_device to meson_pwm_calc() Martin Blumenstingl
2019-05-27 12:27 ` Neil Armstrong
2019-05-25 18:11 ` [PATCH 07/14] pwm: meson: add the meson_pwm_channel data to struct meson_pwm Martin Blumenstingl
2019-05-27 12:27 ` Neil Armstrong
2019-05-27 17:52 ` Martin Blumenstingl
2019-05-25 18:11 ` [PATCH 08/14] pwm: meson: add the per-channel register offsets and bits in a struct Martin Blumenstingl
2019-05-27 12:28 ` Neil Armstrong
2019-05-27 17:57 ` Martin Blumenstingl
2019-05-28 8:11 ` Neil Armstrong
2019-05-25 18:11 ` [PATCH 09/14] pwm: meson: move pwm_set_chip_data() to meson_pwm_request() Martin Blumenstingl
2019-05-27 12:30 ` Neil Armstrong
2019-05-25 18:11 ` [PATCH 10/14] pwm: meson: simplify the calculation of the pre-divider and count Martin Blumenstingl
2019-05-26 19:41 ` Uwe Kleine-König
2019-05-27 12:37 ` Neil Armstrong
2019-05-25 18:11 ` [PATCH 11/14] pwm: meson: read the full hardware state in meson_pwm_get_state() Martin Blumenstingl
2019-05-27 12:31 ` Neil Armstrong
2019-05-25 18:11 ` [PATCH 12/14] pwm: meson: don't cache struct pwm_state internally Martin Blumenstingl
2019-05-27 12:31 ` Neil Armstrong
2019-05-25 18:11 ` [PATCH 13/14] pwm: meson: add support PWM_POLARITY_INVERSED when disabling Martin Blumenstingl
2019-05-27 12:33 ` Neil Armstrong
2019-05-27 17:50 ` Martin Blumenstingl
2019-05-25 18:11 ` [PATCH 14/14] pwm: meson: add documentation to the driver Martin Blumenstingl
2019-05-27 12:33 ` Neil Armstrong
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