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Date:   Sun, 10 Apr 2022 17:18:43 +0300
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Subject: Re: [Patch v6 1/4] memory: tegra: Add memory controller channels
 support
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To:     Ashish Mhetre <amhetre@nvidia.com>, krzysztof.kozlowski@linaro.org,
        thierry.reding@gmail.com, jonathanh@nvidia.com, robh+dt@kernel.org,
        linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
        linux-tegra@vger.kernel.org, krzysztof.kozlowski+dt@linaro.org
Cc:     vdumpa@nvidia.com, Snikam@nvidia.com
References: <20220406052459.10438-1-amhetre@nvidia.com>
 <20220406052459.10438-2-amhetre@nvidia.com>
From:   Dmitry Osipenko <digetx@gmail.com>
In-Reply-To: <20220406052459.10438-2-amhetre@nvidia.com>
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Precedence: bulk

06.04.2022 08:24, Ashish Mhetre пишет:
> +	num_dt_channels = of_property_count_elems_of_size(pdev->dev.of_node, "reg",
> +							  reg_cells * sizeof(u32));
> +	/*
> +	 * On tegra186 onwards, memory controller support multiple channels.
> +	 * Apart from regular memory controller channels, there is one broadcast
> +	 * channel and one for stream-id registers.
> +	 */
> +	if (num_dt_channels < mc->soc->num_channels + 2) {
> +		dev_warn(&pdev->dev, "MC channels are missing, please update memory controller DT node with MC channels\n");
> +		return 0;
> +	}
> +
> +	mc->bcast_ch_regs = devm_platform_ioremap_resource_byname(pdev, "mc-broadcast");
> +	if (IS_ERR(mc->bcast_ch_regs))
> +		return PTR_ERR(mc->bcast_ch_regs);

Looks to me that you don't need to use of_property_count_elems_of_size()
and could only check the "mc-broadcast" presence to decide whether this
is an older DT.

mc->bcast_ch_regs = devm_platform_ioremap_resource_byname(pdev,
"broadcast");
if (IS_ERR(mc->bcast_ch_regs)) {
	dev_warn(&pdev->dev, "Broadcast channel is missing, please update your
device-tree\n");
	return PTR_ERR(mc->bcast_ch_regs);
}