Date:   Wed, 8 Mar 2023 21:37:59 +0800
From:   Jianhua Lu <lujianhua000@gmail.com>
To:     Konrad Dybcio <konrad.dybcio@linaro.org>
Cc:     Thierry Reding <thierry.reding@gmail.com>,
        Sam Ravnborg <sam@ravnborg.org>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Linus Walleij <linus.walleij@linaro.org>,
        Neil Armstrong <neil.armstrong@linaro.org>,
        dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        ~postmarketos/upstreaming@lists.sr.ht, phone-devel@vger.kernel.org
Subject: Re: [PATCH v3 2/2] drm/panel: Add driver for Novatek NT36523
Message-ID: <ZAiPTat/kmLyaJmA@Gentoo>
References: <20230308043706.16318-1-lujianhua000@gmail.com>
 <20230308043706.16318-2-lujianhua000@gmail.com>
 <66d293a8-f850-cb80-0c83-2ebf7e29d0c2@linaro.org>
 <ZAh3MSpQ30YyPAVe@Gentoo>
 <1cbe9e29-13a4-574e-6d8c-b2506e7a36b3@linaro.org>
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On Wed, Mar 08, 2023 at 01:33:39PM +0100, Konrad Dybcio wrote:
> 
> phy-type:
>     description: D-PHY (default) or C-PHY mode
>     enum: [ 10, 11 ]
>     default: 10
> 
> try setting that to 11 under your DSI PHYs (or one? not sure).
I already used phy-type = <PHY_TYPE_CPHY> before, this equate to qcom,panel-cphy-mode in
downstream panel device tree, but there is qcom,mdss-dsi-cphy-strength isn't
implemented.
> Konrad
> > 
> >> Could you also implement a 60 (or whatever other value is also
> >> implemented downstream) Hz mode?
> > I will try to implement it.
> >>
> >>> +	.clock = (1600 + 60 + 8 + 60) * (2560 + 26 + 4 + 168) * 104 / 1000,
> >>> +	.hdisplay = 1600,
> >>> +	.hsync_start = 1600 + 60,
> >>> +	.hsync_end = 1600 + 60 + 8,
> >>> +	.htotal = 1600 + 60 + 8 + 60,
> >>> +	.vdisplay = 2560,
> >>> +	.vsync_start = 2560 + 26,
> >>> +	.vsync_end = 2560 + 26 + 4,
> >>> +	.vtotal = 2560 + 26 + 4 + 168,
> >>> +};
> >>> +
> >>> +static const struct drm_display_mode elish_csot_mode = {
> >>> +	/* Current max freqency is 104HZ, TODO 120HZ */
> >>> +	.clock = (1600 + 200 + 40 + 52) * (2560 + 26 + 4 + 168) * 104 / 1000,
> >>> +	.hdisplay = 1600,
> >>> +	.hsync_start = 1600 + 200,
> >>> +	.hsync_end = 1600 + 200 + 40,
> >>> +	.htotal = 1600 + 200 + 40 + 52,
> >>> +	.vdisplay = 2560,
> >>> +	.vsync_start = 2560 + 26,
> >>> +	.vsync_end = 2560 + 26 + 4,
> >>> +	.vtotal = 2560 + 26 + 4 + 168,
> >>> +};
> >>> +
> >>> +static const struct panel_desc elish_boe_desc = {
> >>> +	.modes = &elish_boe_mode,
> >>> +	.dsi_info = {
> >>> +		.type = "NT36523",
> >> That's a bit vague, the driver IC is not very telling about the
> >> panel itself. Since we're not able to determine much more information,
> >> this could contain the panel manufacturer and the device name.
> > Acked.
> >>
> >>> +		.channel = 0,
> >>> +		.node = NULL,
> >>> +	},
> >>> +	.width_mm = 127,
> >>> +	.height_mm = 203,
> >>> +	.bpc = 8,
> >>> +	.lanes = 3,
> >>> +	.format = MIPI_DSI_FMT_RGB888,
> >>> +	.mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_CLOCK_NON_CONTINUOUS | MIPI_DSI_MODE_LPM,
> >>> +	.init_sequence = elish_boe_init_sequence,
> >>> +	.is_dual_dsi = true,
> >>> +};
> >>> +
> >> [...]
> >>
> >>> +static int nt36523_probe(struct mipi_dsi_device *dsi)
> >>> +{
> >> [...]
> >>
> >>> +	/* If the panel is dual dsi, register DSI1 */
> >>> +	if (pinfo->desc->is_dual_dsi) {
> >>> +		info = &pinfo->desc->dsi_info;
> >>> +
> >>> +		dsi1 = of_graph_get_remote_node(dsi->dev.of_node, 1, -1);
> >>> +		if (!dsi1) {
> >>> +			dev_err(dev, "cannot get secondary DSI node.\n");
> >>> +			return -ENODEV;
> >>> +		}
> >>> +
> >>> +		dsi1_host = of_find_mipi_dsi_host_by_node(dsi1);
> >>> +		of_node_put(dsi1);
> >> Shouldn't you put the reference only if it's found?
> > thanks for spot it.
> >>
> >>> +		if (!dsi1_host) {
> >>> +			dev_err(dev, "cannot get secondary DSI host\n");
> >>> +			return -EPROBE_DEFER;
> >> dev_err_probe, here and in neighbouring exit return paths?
> > Acked.
> >>
> >>
> >> Konrad