From: Dave Stevenson <dave.stevenson@raspberrypi.com>
To: Maxime Ripard <maxime@cerno.tech>
Cc: Eric Anholt <eric@anholt.net>,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Thomas Zimmermann <tzimmermann@suse.de>,
Daniel Vetter <daniel.vetter@intel.com>,
David Airlie <airlied@linux.ie>,
Jason Cooper <jason@lakedaemon.net>,
bcm-kernel-feedback-list@broadcom.com,
linux-arm-kernel@lists.infradead.org,
Marc Zyngier <maz@kernel.org>,
Linux Media Mailing List <linux-media@vger.kernel.org>,
Hans Verkuil <hverkuil-cisco@xs4all.nl>,
LKML <linux-kernel@vger.kernel.org>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
linux-rpi-kernel@lists.infradead.org,
DRI Development <dri-devel@lists.freedesktop.org>
Subject: Re: [PATCH 06/15] drm/vc4: hdmi: Compute the CEC clock divider from the clock rate
Date: Fri, 18 Dec 2020 11:30:27 +0000 [thread overview]
Message-ID: <CAPY8ntBySziAsVk+UDP9myF-zA5bUmWcYVUGir3e=_o_DhQsjg@mail.gmail.com> (raw)
In-Reply-To: <20201210134648.272857-7-maxime@cerno.tech>
Hi Maxime
On Thu, 10 Dec 2020 at 13:47, Maxime Ripard <maxime@cerno.tech> wrote:
>
> The CEC clock divider needs to output a frequency of 40kHz from the HSM
> rate on the BCM2835. The driver used to have a fixed frequency for it,
> but that changed and we now need to compute it dynamically to maintain
> the proper rate.
>
> Fixes: cd4cb49dc5bb ("drm/vc4: hdmi: Adjust HSM clock rate depending on pixel rate")
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
(To be a total pedant it's still a fixed frequency on vc4, but it's
configurable via the variant entry).
> ---
> drivers/gpu/drm/vc4/vc4_hdmi.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
> index eff3bac562c6..0c53d7427d15 100644
> --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
> @@ -1586,6 +1586,7 @@ static int vc4_hdmi_cec_init(struct vc4_hdmi *vc4_hdmi)
> {
> struct cec_connector_info conn_info;
> struct platform_device *pdev = vc4_hdmi->pdev;
> + u16 clk_cnt;
> u32 value;
> int ret;
>
> @@ -1611,8 +1612,9 @@ static int vc4_hdmi_cec_init(struct vc4_hdmi *vc4_hdmi)
> * divider: the hsm_clock rate and this divider setting will
> * give a 40 kHz CEC clock.
> */
> + clk_cnt = clk_get_rate(vc4_hdmi->hsm_clock) / CEC_CLOCK_FREQ;
> value |= VC4_HDMI_CEC_ADDR_MASK |
> - (4091 << VC4_HDMI_CEC_DIV_CLK_CNT_SHIFT);
> + (clk_cnt << VC4_HDMI_CEC_DIV_CLK_CNT_SHIFT);
> HDMI_WRITE(HDMI_CEC_CNTRL_1, value);
> ret = devm_request_threaded_irq(&pdev->dev, platform_get_irq(pdev, 0),
> vc4_cec_irq_handler,
> --
> 2.28.0
>
next prev parent reply other threads:[~2020-12-18 11:31 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-10 13:46 [PATCH 00/15] drm/vc4: hdmi: Add CEC support for the BCM2711 Maxime Ripard
2020-12-10 13:46 ` [PATCH 01/15] irqchip: Allow to compile bcmstb on other platforms Maxime Ripard
2020-12-10 17:33 ` Florian Fainelli
2020-12-10 17:59 ` Marc Zyngier
2020-12-14 15:27 ` Maxime Ripard
2020-12-14 16:20 ` Marc Zyngier
2020-12-10 13:46 ` [PATCH 02/15] drm/vc4: hdmi: Move hdmi reset to bind Maxime Ripard
2020-12-18 11:20 ` Dave Stevenson
2020-12-10 13:46 ` [PATCH 03/15] drm/vc4: hdmi: Fix register offset with longer CEC messages Maxime Ripard
2020-12-15 11:23 ` Dave Stevenson
2020-12-10 13:46 ` [PATCH 04/15] drm/vc4: hdmi: Fix up CEC registers Maxime Ripard
2020-12-18 11:21 ` Dave Stevenson
2020-12-10 13:46 ` [PATCH 05/15] drm/vc4: hdmi: Restore cec physical address on reconnect Maxime Ripard
2020-12-18 14:21 ` Dave Stevenson
2020-12-18 14:45 ` Dave Stevenson
2021-01-11 10:29 ` Maxime Ripard
2020-12-10 13:46 ` [PATCH 06/15] drm/vc4: hdmi: Compute the CEC clock divider from the clock rate Maxime Ripard
2020-12-18 11:30 ` Dave Stevenson [this message]
2020-12-10 13:46 ` [PATCH 07/15] drm/vc4: hdmi: Update the CEC clock divider on HSM rate change Maxime Ripard
2020-12-18 14:26 ` Dave Stevenson
2020-12-10 13:46 ` [PATCH 08/15] drm/vc4: hdmi: Introduce a CEC clock Maxime Ripard
2020-12-18 11:37 ` Dave Stevenson
2020-12-18 12:23 ` Maxime Ripard
2020-12-18 12:25 ` Dave Stevenson
2020-12-10 13:46 ` [PATCH 09/15] drm/vc4: hdmi: Split the interrupt handlers Maxime Ripard
2020-12-10 13:46 ` [PATCH 10/15] drm/vc4: hdmi: Support BCM2711 CEC interrupt setup Maxime Ripard
2020-12-10 13:46 ` [PATCH 11/15] drm/vc4: hdmi: Remove cec_available flag Maxime Ripard
2020-12-18 14:30 ` Dave Stevenson
2020-12-10 13:46 ` [PATCH 12/15] drm/vc4: hdmi: Don't register the CEC adapter if there's no interrupts Maxime Ripard
2020-12-18 14:29 ` Dave Stevenson
2020-12-10 13:46 ` [PATCH 13/15] dt-binding: display: bcm2711-hdmi: Add CEC and hotplug interrupts Maxime Ripard
2020-12-10 13:46 ` [PATCH 14/15] ARM: dts: bcm2711: Add the BSC interrupt controller Maxime Ripard
2020-12-10 17:41 ` Florian Fainelli
2020-12-10 13:46 ` [PATCH 15/15] ARM: dts: bcm2711: Add the CEC " Maxime Ripard
2020-12-10 17:42 ` Florian Fainelli
2020-12-16 12:35 ` [PATCH 00/15] drm/vc4: hdmi: Add CEC support for the BCM2711 Hans Verkuil
2020-12-17 10:49 ` Maxime Ripard
2020-12-17 10:53 ` Hans Verkuil
2020-12-17 12:59 ` Maxime Ripard
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