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Subject: Re: [PATCH v12 4/9] drm/ingenic: Add dw-hdmi driver specialization
 for jz4780
From:   "H. Nikolaus Schaller" <hns@goldelico.com>
In-Reply-To: <1W9O6R.U3T9L7GOJNE81@crapouillou.net>
Date:   Wed, 2 Feb 2022 12:42:37 +0100
Cc:     Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        Kees Cook <keescook@chromium.org>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Neil Armstrong <narmstrong@baylibre.com>,
        Robert Foss <robert.foss@linaro.org>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
        Jernej Skrabec <jernej.skrabec@gmail.com>,
        Harry Wentland <harry.wentland@amd.com>,
        Sam Ravnborg <sam@ravnborg.org>,
        Maxime Ripard <maxime@cerno.tech>,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        Paul Boddie <paul@boddie.org.uk>,
        Andrzej Hajda <andrzej.hajda@intel.com>,
        Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>,
        devicetree@vger.kernel.org, linux-mips@vger.kernel.org,
        linux-kernel@vger.kernel.org, letux-kernel@openphoenux.org,
        Jonas Karlman <jonas@kwiboo.se>,
        dri-devel@lists.freedesktop.org,
        Ezequiel Garcia <ezequiel@collabora.com>
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Message-Id: <8126F638-201E-4EB4-A0D9-847A6A6609EF@goldelico.com>
References: <cover.1643632014.git.hns@goldelico.com>
 <d723efc7c2544db945698246ae4644ecb8fae1a3.1643632014.git.hns@goldelico.com>
 <1W9O6R.U3T9L7GOJNE81@crapouillou.net>
To:     Paul Cercueil <paul@crapouillou.net>
Precedence: bulk

Hi Paul,

> Am 02.02.2022 um 11:16 schrieb Paul Cercueil <paul@crapouillou.net>:
>=20
> Hi Nikolaus,
>=20
> Le lun., janv. 31 2022 at 13:26:50 +0100, H. Nikolaus Schaller =
<hns@goldelico.com> a =C3=A9crit :
>> From: Paul Boddie <paul@boddie.org.uk>
>> A specialisation of the generic Synopsys HDMI driver is employed for
>> JZ4780 HDMI support. This requires a new driver, plus device tree and
>> configuration modifications.
>> Here we add Kconfig DRM_INGENIC_DW_HDMI, Makefile and driver code.
>> Signed-off-by: Paul Boddie <paul@boddie.org.uk>
>> Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
>> Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
>> ---
>> drivers/gpu/drm/ingenic/Kconfig           |   9 ++
>> drivers/gpu/drm/ingenic/Makefile          |   1 +
>> drivers/gpu/drm/ingenic/ingenic-dw-hdmi.c | 104 =
++++++++++++++++++++++
>> 3 files changed, 114 insertions(+)
>> create mode 100644 drivers/gpu/drm/ingenic/ingenic-dw-hdmi.c
>> diff --git a/drivers/gpu/drm/ingenic/Kconfig =
b/drivers/gpu/drm/ingenic/Kconfig
>> index 001f59fb06d56..ba4a650869cd8 100644
>> --- a/drivers/gpu/drm/ingenic/Kconfig
>> +++ b/drivers/gpu/drm/ingenic/Kconfig
>> @@ -24,4 +24,13 @@ config DRM_INGENIC_IPU
>> 	  The Image Processing Unit (IPU) will appear as a second =
primary plane.
>> +config DRM_INGENIC_DW_HDMI
>> +	tristate "Ingenic specific support for Synopsys DW HDMI"
>> +	depends on MACH_JZ4780
>> +	select DRM_DW_HDMI
>> +	help
>> +	  Choose this option to enable Synopsys DesignWare HDMI based =
driver.
>> +	  If you want to enable HDMI on Ingenic JZ4780 based SoC, you =
should
>> +	  select this option..
>=20
> One dot is enough.

Ok, will fix.

>=20
>> +
>> endif
>> diff --git a/drivers/gpu/drm/ingenic/Makefile =
b/drivers/gpu/drm/ingenic/Makefile
>> index d313326bdddbb..f10cc1c5a5f22 100644
>> --- a/drivers/gpu/drm/ingenic/Makefile
>> +++ b/drivers/gpu/drm/ingenic/Makefile
>> @@ -1,3 +1,4 @@
>> obj-$(CONFIG_DRM_INGENIC) +=3D ingenic-drm.o
>> ingenic-drm-y =3D ingenic-drm-drv.o
>> ingenic-drm-$(CONFIG_DRM_INGENIC_IPU) +=3D ingenic-ipu.o
>> +obj-$(CONFIG_DRM_INGENIC_DW_HDMI) +=3D ingenic-dw-hdmi.o
>> diff --git a/drivers/gpu/drm/ingenic/ingenic-dw-hdmi.c =
b/drivers/gpu/drm/ingenic/ingenic-dw-hdmi.c
>> new file mode 100644
>> index 0000000000000..34e986dd606cf
>> --- /dev/null
>> +++ b/drivers/gpu/drm/ingenic/ingenic-dw-hdmi.c
>> @@ -0,0 +1,104 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/* Copyright (C) 2011-2013 Freescale Semiconductor, Inc.
>> + * Copyright (C) 2019, 2020 Paul Boddie <paul@boddie.org.uk>
>> + *
>> + * Derived from dw_hdmi-imx.c with i.MX portions removed.
>> + * Probe and remove operations derived from rcar_dw_hdmi.c.
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/of_platform.h>
>> +#include <linux/platform_device.h>
>> +
>> +#include <drm/bridge/dw_hdmi.h>
>> +#include <drm/drm_of.h>
>> +#include <drm/drm_print.h>
>> +
>> +static const struct dw_hdmi_mpll_config ingenic_mpll_cfg[] =3D {
>> +	{ 45250000,  { { 0x01e0, 0x0000 }, { 0x21e1, 0x0000 }, { 0x41e2, =
0x0000 } } },
>> +	{ 92500000,  { { 0x0140, 0x0005 }, { 0x2141, 0x0005 }, { 0x4142, =
0x0005 } } },
>> +	{ 148500000, { { 0x00a0, 0x000a }, { 0x20a1, 0x000a }, { 0x40a2, =
0x000a } } },
>> +	{ 216000000, { { 0x00a0, 0x000a }, { 0x2001, 0x000f }, { 0x4002, =
0x000f } } },
>> +	{ ~0UL,      { { 0x0000, 0x0000 }, { 0x0000, 0x0000 }, { 0x0000, =
0x0000 } } }
>> +};
>> +
>> +static const struct dw_hdmi_curr_ctrl ingenic_cur_ctr[] =3D {
>> +	/*pixelclk     bpp8    bpp10   bpp12 */
>> +	{ 54000000,  { 0x091c, 0x091c, 0x06dc } },
>> +	{ 58400000,  { 0x091c, 0x06dc, 0x06dc } },
>> +	{ 72000000,  { 0x06dc, 0x06dc, 0x091c } },
>> +	{ 74250000,  { 0x06dc, 0x0b5c, 0x091c } },
>> +	{ 118800000, { 0x091c, 0x091c, 0x06dc } },
>> +	{ 216000000, { 0x06dc, 0x0b5c, 0x091c } },
>> +	{ ~0UL,      { 0x0000, 0x0000, 0x0000 } },
>> +};
>> +
>> +/*
>> + * Resistance term 133Ohm Cfg
>> + * PREEMP config 0.00
>> + * TX/CK level 10
>> + */
>> +static const struct dw_hdmi_phy_config ingenic_phy_config[] =3D {
>> +	/*pixelclk   symbol   term   vlev */
>> +	{ 216000000, 0x800d, 0x0005, 0x01ad},
>> +	{ ~0UL,      0x0000, 0x0000, 0x0000}
>> +};
>> +
>> +static enum drm_mode_status
>> +ingenic_dw_hdmi_mode_valid(struct dw_hdmi *hdmi, void *data,
>> +			   const struct drm_display_info *info,
>> +			   const struct drm_display_mode *mode)
>> +{
>> +	if (mode->clock < 13500)
>> +		return MODE_CLOCK_LOW;
>> +	/* FIXME: Hardware is capable of 270MHz, but setup data is =
missing. */
>> +	if (mode->clock > 216000)
>> +		return MODE_CLOCK_HIGH;
>> +
>> +	return MODE_OK;
>> +}
>> +
>> +static struct dw_hdmi_plat_data ingenic_dw_hdmi_plat_data =3D {
>> +	.mpll_cfg   =3D ingenic_mpll_cfg,
>> +	.cur_ctr    =3D ingenic_cur_ctr,
>> +	.phy_config =3D ingenic_phy_config,
>> +	.mode_valid =3D ingenic_dw_hdmi_mode_valid,
>> +	.output_port	=3D 1,
>> +};
>> +
>> +static const struct of_device_id ingenic_dw_hdmi_dt_ids[] =3D {
>> +	{ .compatible =3D "ingenic,jz4780-dw-hdmi" },
>> +	{ /* Sentinel */ },
>> +};
>> +MODULE_DEVICE_TABLE(of, ingenic_dw_hdmi_dt_ids);
>> +
>> +static void ingenic_dw_hdmi_cleanup(void *data)
>> +{
>> +	struct dw_hdmi *hdmi =3D (struct dw_hdmi *)data;
>> +
>> +	dw_hdmi_remove(hdmi);
>> +}
>> +
>> +static int ingenic_dw_hdmi_probe(struct platform_device *pdev)
>> +{
>> +	struct dw_hdmi *hdmi;
>> +
>> +	hdmi =3D dw_hdmi_probe(pdev, &ingenic_dw_hdmi_plat_data);
>> +	if (IS_ERR(hdmi))
>> +		return PTR_ERR(hdmi);
>> +
>> +	return devm_add_action_or_reset(&pdev->dev, =
ingenic_dw_hdmi_cleanup, hdmi);
>=20
> Nitpick, but your probe function is so simple, you could just have a =
.remove callback

Well, we did have one in v5 or so (haven't looked back) and it was your =
suggestion to
add an action handler. Well at that point it was a little more to do.

> instead of registering a devm action. Then you can just return =
PTR_ERR_OR_ZERO(hdmi).
>=20
> Cheers,
> -Paul