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Message-ID: <5c3c686a-1500-7261-b112-1ea94d9e346e@quicinc.com>
Date: Wed, 20 Dec 2023 13:34:38 +0530
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Subject: Re: [PATCH v2 07/34] media: iris: initialize power resources
Content-Language: en-US
To: Konrad Dybcio <konrad.dybcio@linaro.org>, <linux-media@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <stanimir.k.varbanov@gmail.com>,
        <quic_vgarodia@quicinc.com>, <agross@kernel.org>,
        <andersson@kernel.org>, <mchehab@kernel.org>,
        <bryan.odonoghue@linaro.org>
CC: <linux-arm-msm@vger.kernel.org>, <quic_abhinavk@quicinc.com>
References: <1702899149-21321-1-git-send-email-quic_dikshita@quicinc.com>
 <1702899149-21321-8-git-send-email-quic_dikshita@quicinc.com>
 <6c2e7cac-6f3d-42f0-84de-72a14e8f9ef5@linaro.org>
From: Dikshita Agarwal <quic_dikshita@quicinc.com>
In-Reply-To: <6c2e7cac-6f3d-42f0-84de-72a14e8f9ef5@linaro.org>
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On 12/18/2023 8:39 PM, Konrad Dybcio wrote:
> On 18.12.2023 12:32, Dikshita Agarwal wrote:
>> Add support for initializing Iris "resources", which are clocks,
>> interconnects, power domains, reset clocks, and clock frequencies
>> used for Iris hardware.
>>
>> Signed-off-by: Dikshita Agarwal <quic_dikshita@quicinc.com>
>> ---
> [...]
> 
>> +	ret = init_resources(core);
>> +	if (ret) {
>> +		dev_err_probe(core->dev, ret,
>> +			      "%s: init resource failed with %d\n", __func__, ret);
>> +		return ret;
> You're supposed to return dev_err_probe, it propagates the errors
> this way
> 
Sure, fix this.
> Also, I think __func__ is excessive, throughout the code. You can
> very quickly grep for the error messages, which are quite unique.
> 
Ok, will remove __func__
> [...]
> 
>> +
>> +static const struct bus_info plat_bus_table[] = {
>> +	{ NULL, "iris-cnoc", 1000, 1000     },
>> +	{ NULL, "iris-ddr",  1000, 15000000 },
>> +};
>> +
>> +static const char * const plat_pd_table[] = { "iris-ctl", "vcodec", NULL };
>> +#define PD_COUNT 2
>> +
>> +static const char * const plat_opp_pd_table[] = { "mxc", "mmcx", NULL };
>> +#define OPP_PD_COUNT 2
>> +
>> +static const struct clock_info plat_clk_table[] = {
>> +	{ NULL, "gcc_video_axi0", GCC_VIDEO_AXI0_CLK, 0, 0 },
>> +	{ NULL, "core_clk",       VIDEO_CC_MVS0C_CLK, 0, 0 },
>> +	{ NULL, "vcodec_core",    VIDEO_CC_MVS0_CLK,  1, 0 },
>> +};
>> +
>> +static const char * const plat_clk_reset_table[] = { "video_axi_reset", NULL };
>> +#define RESET_COUNT 1
> Are you sure this won't change between platforms?
> [...]
> 
yes, these will change, but since at this point in the patches, I have not
introduced platform specific file, added these tables here.
I am moving these to platform specific file when I introduce that in
patch-13 [1].

[1]
https://patchwork.kernel.org/project/linux-media/patch/1702899149-21321-14-git-send-email-quic_dikshita@quicinc.com/
>> +static int init_bus(struct iris_core *core)
>> +{
>> +	struct bus_info *binfo = NULL;
>> +	u32 i = 0;
> no need to initialize
> 
Sure, will fix.
> [...]
> 
>> +static int init_clocks(struct iris_core *core)
>> +{
>> +	struct clock_info *cinfo = NULL;
>> +	u32 i;
>> +
>> +	core->clk_count = ARRAY_SIZE(plat_clk_table);
>> +	core->clock_tbl = devm_kzalloc(core->dev,
>> +				       sizeof(struct clock_info) * core->clk_count,
>> +				       GFP_KERNEL);
>> +	if (!core->clock_tbl)
>> +		return -ENOMEM;
>> +
>> +	for (i = 0; i < core->clk_count; i++) {
>> +		cinfo = &core->clock_tbl[i];
>> +		cinfo->name = plat_clk_table[i].name;
>> +		cinfo->clk_id = plat_clk_table[i].clk_id;
>> +		cinfo->has_scaling = plat_clk_table[i].has_scaling;
>> +		cinfo->clk = devm_clk_get(core->dev, cinfo->name);
>> +		if (IS_ERR(cinfo->clk)) {
>> +			dev_err(core->dev,
>> +				"%s: failed to get clock: %s\n", __func__, cinfo->name);
>> +			return PTR_ERR(cinfo->clk);
>> +		}
>> +	}
> Are you not going to use OPP for scaling the main RPMhPD with the core
> clock?
> 
We are using OPP for scaling the vcodec clk.
Could you please elaborate you query here, may be I didn't understand fully.
>> +
>> +	return 0;
>> +}
>> +
>> +static int init_reset_clocks(struct iris_core *core)
> init_resets
> 
> 'reset clocks' is an old downstream concept
> 
Sure, I can rename it.
>> +{
>> +	struct reset_info *rinfo = NULL;
>> +	u32 i = 0;
> unnecessary initializations
> 
Sure, will fix.
> [...]
> 
>> +
>> +int init_resources(struct iris_core *core)
>> +{
>> +	int ret;
>> +
>> +	ret = init_bus(core);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = init_power_domains(core);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = init_clocks(core);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = init_reset_clocks(core);
>> +
>> +	return ret;
> return init_reset_clocks(core);
> 
>> +}
>> diff --git a/drivers/media/platform/qcom/vcodec/iris/resources.h b/drivers/media/platform/qcom/vcodec/iris/resources.h
>> new file mode 100644
>> index 0000000..d21bcc7e
>> --- /dev/null
>> +++ b/drivers/media/platform/qcom/vcodec/iris/resources.h
>> @@ -0,0 +1,36 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
>> + */
>> +
>> +#ifndef _RESOURCES_H_
>> +#define _RESOURCES_H_
>> +
>> +struct bus_info {
>> +	struct icc_path		*icc;
>> +	const char		*name;
>> +	u32			bw_min_kbps;
>> +	u32			bw_max_kbps;
> u64?
> 
Will check and do the needful.
>> +};
>> +
>> +struct power_domain_info {
>> +	struct device	*genpd_dev;
>> +	const char	*name;
>> +};
>> +
>> +struct clock_info {
>> +	struct clk	*clk;
>> +	const char	*name;
> I'm not sure why you need it
> 
>> +	u32		clk_id;
> Or this
> 
>> +	bool		has_scaling;
> Or this
> 
> you could probably do something like this:
> 
> struct big_iris_struct {
> 	[...]
> 	struct clk *core_clk;
> 	struct clk *memory_clk;
> 	struct clk *some_important_scaled_clock;
> 	struct clk_bulk_data less_important_nonscaling_clocks[X]
> }
> 
> and then make use of all of the great common upstream APIs to manage
> them!
> 
Will explore this and get back.
>> +	u64		prev;
>> +};
>> +
>> +struct reset_info {
>> +	struct reset_control	*rst;
>> +	const char		*name;
> this seems a bit excessive as well
> 
> Konrad