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Message-ID: <876010c1-0558-bd1e-e133-05403e5a167b@nvidia.com>
Date:   Wed, 9 Mar 2022 08:56:01 +0000
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Subject: Re: [Patch v4 3/4] memory: tegra: Add memory controller channels
 support
Content-Language: en-US
To:     Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>,
        Ashish Mhetre <amhetre@nvidia.com>, robh+dt@kernel.org,
        thierry.reding@gmail.com, digetx@gmail.com,
        linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
        linux-tegra@vger.kernel.org
Cc:     vdumpa@nvidia.com, Snikam@nvidia.com
References: <1646210609-21943-1-git-send-email-amhetre@nvidia.com>
 <1646210609-21943-4-git-send-email-amhetre@nvidia.com>
 <34646ebd-2c37-65ec-ecfe-cfbfa4bd29d2@canonical.com>
From:   Jon Hunter <jonathanh@nvidia.com>
In-Reply-To: <34646ebd-2c37-65ec-ecfe-cfbfa4bd29d2@canonical.com>
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On 02/03/2022 19:35, Krzysztof Kozlowski wrote:
> On 02/03/2022 09:43, Ashish Mhetre wrote:
>>  From tegra186 onwards, memory controller support multiple channels.
>> Add support for mapping address spaces of these channels.
>> During error interrupts from memory controller, appropriate registers
>> from these channels need to be accessed for logging error info.
>>
>> Signed-off-by: Ashish Mhetre <amhetre@nvidia.com>
>> ---
>>   drivers/memory/tegra/mc.c       |  6 ++++++
>>   drivers/memory/tegra/tegra186.c | 21 +++++++++++++++++++++
>>   drivers/memory/tegra/tegra194.c |  1 +
>>   drivers/memory/tegra/tegra234.c |  1 +
>>   include/soc/tegra/mc.h          |  7 +++++++
>>   5 files changed, 36 insertions(+)
>>
>> diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c
>> index bf3abb6..3cda1d9 100644
>> --- a/drivers/memory/tegra/mc.c
>> +++ b/drivers/memory/tegra/mc.c
>> @@ -749,6 +749,12 @@ static int tegra_mc_probe(struct platform_device *pdev)
>>   	if (IS_ERR(mc->regs))
>>   		return PTR_ERR(mc->regs);
>>   
>> +	if (mc->soc->ops && mc->soc->ops->map_regs) {
>> +		err = mc->soc->ops->map_regs(mc, pdev);
>> +		if (err < 0)
>> +			return err;
>> +	}
>> +
>>   	mc->debugfs.root = debugfs_create_dir("mc", NULL);
>>   
>>   	if (mc->soc->ops && mc->soc->ops->probe) {
>> diff --git a/drivers/memory/tegra/tegra186.c b/drivers/memory/tegra/tegra186.c
>> index 3d15388..59a4425 100644
>> --- a/drivers/memory/tegra/tegra186.c
>> +++ b/drivers/memory/tegra/tegra186.c
>> @@ -139,11 +139,31 @@ static int tegra186_mc_probe_device(struct tegra_mc *mc, struct device *dev)
>>   	return 0;
>>   }
>>   
>> +static int tegra186_mc_map_regs(struct tegra_mc *mc,
>> +				struct platform_device *pdev)
>> +{
>> +	struct resource *res;
>> +	int i;
>> +
>> +	mc->mcb_regs = devm_platform_get_and_ioremap_resource(pdev, 1, &res);
>> +	if (IS_ERR(mc->mcb_regs))
>> +		return PTR_ERR(mc->mcb_regs);
>> +
>> +	for (i = 0; i < mc->soc->num_channels; i++) {
>> +		mc->mc_regs[i] = devm_platform_get_and_ioremap_resource(pdev, i + 2, &res);
>> +		if (IS_ERR(mc->mc_regs[i]))
>> +			return PTR_ERR(mc->mc_regs[i]);
> 
> This breaks the ABI, so I need Thierry's ack that such ABI break is
> perfectly ok.


We should not break the DT ABI and so if all the reg entries it should 
still be able to work.

Jon

-- 
nvpublic