linux-kernel - Re: [PATCH v1 03/11] clk: starfive: Add StarFive JH7110 System-Top-Group clock driver

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Message-ID: <0e77bf23-b359-9884-6a8c-368e31d718a4@starfivetech.com>
Date:   Mon, 30 Jan 2023 16:02:28 +0800
From:   Xingyu Wu <xingyu.wu@...rfivetech.com>
To:     Stephen Boyd <sboyd@...nel.org>,
        Emil Renner Berthing <kernel@...il.dk>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Michael Turquette <mturquette@...libre.com>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        <devicetree@...r.kernel.org>, <linux-riscv@...ts.infradead.org>
CC:     Rob Herring <robh+dt@...nel.org>, Conor Dooley <conor@...nel.org>,
        "Paul Walmsley" <paul.walmsley@...ive.com>,
        Palmer Dabbelt <palmer@...belt.com>,
        Albert Ou <aou@...s.berkeley.edu>,
        Hal Feng <hal.feng@...rfivetech.com>,
        <linux-kernel@...r.kernel.org>, <linux-clk@...r.kernel.org>
Subject: Re: [PATCH v1 03/11] clk: starfive: Add StarFive JH7110
 System-Top-Group clock driver

On 2023/1/26 10:33, Stephen Boyd wrote:
> Quoting Xingyu Wu (2023-01-19 18:44:37)
>> diff --git a/drivers/clk/starfive/clk-starfive-jh7110-stg.c b/drivers/clk/starfive/clk-starfive-jh7110-stg.c
>> new file mode 100644
>> index 000000000000..c2740f44e796
>> --- /dev/null
>> +++ b/drivers/clk/starfive/clk-starfive-jh7110-stg.c
>> @@ -0,0 +1,180 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * StarFive JH7110 System-Top-Group Clock Driver
>> + *
>> + * Copyright (C) 2022 StarFive Technology Co., Ltd.
>> + */
>> +
>> +#include <linux/clk.h>
> 
> Is this include used? If not, please remove.

Will drop in next patch.


> 
>> +#include <linux/clk-provider.h>
>> +#include <linux/io.h>
>> +#include <linux/of.h>
>> +#include <linux/platform_device.h>
>> +
>> +#include <dt-bindings/clock/starfive,jh7110-crg.h>
>> +
>> +#include "clk-starfive-jh71x0.h"
>> +
> [...]
>> +static int jh7110_stgcrg_probe(struct platform_device *pdev)
>> +{
>> +       struct jh71x0_clk_priv *priv;
>> +       unsigned int idx;
>> +       int ret;
>> +
>> +       priv = devm_kzalloc(&pdev->dev,
>> +                           struct_size(priv, reg, JH7110_STGCLK_END),
>> +                           GFP_KERNEL);
>> +       if (!priv)
>> +               return -ENOMEM;
>> +
>> +       spin_lock_init(&priv->rmw_lock);
>> +       priv->dev = &pdev->dev;
>> +       priv->base = devm_platform_ioremap_resource(pdev, 0);
>> +       if (IS_ERR(priv->base))
>> +               return PTR_ERR(priv->base);
>> +
>> +       dev_set_drvdata(priv->dev, priv->base);
>> +
>> +       for (idx = 0; idx < JH7110_STGCLK_END; idx++) {
>> +               u32 max = jh7110_stgclk_data[idx].max;
>> +               struct clk_parent_data parents[4] = {};
>> +               struct clk_init_data init = {
>> +                       .name = jh7110_stgclk_data[idx].name,
>> +                       .ops = starfive_jh71x0_clk_ops(max),
>> +                       .parent_data = parents,
>> +                       .num_parents =
>> +                               ((max & JH71X0_CLK_MUX_MASK) >> JH71X0_CLK_MUX_SHIFT) + 1,
>> +                       .flags = jh7110_stgclk_data[idx].flags,
>> +               };
>> +               struct jh71x0_clk *clk = &priv->reg[idx];
>> +               unsigned int i;
>> +
>> +               for (i = 0; i < init.num_parents; i++) {
>> +                       unsigned int pidx = jh7110_stgclk_data[idx].parents[i];
>> +
>> +                       if (pidx < JH7110_STGCLK_END)
>> +                               parents[i].hw = &priv->reg[pidx].hw;
>> +                       else if (pidx == JH7110_STGCLK_OSC)
>> +                               parents[i].fw_name = "osc";
>> +                       else if (pidx == JH7110_STGCLK_HIFI4_CORE)
>> +                               parents[i].fw_name = "hifi4_core";
>> +                       else if (pidx == JH7110_STGCLK_STG_AXIAHB)
>> +                               parents[i].fw_name = "stg_axiahb";
>> +                       else if (pidx == JH7110_STGCLK_USB_125M)
>> +                               parents[i].fw_name = "usb_125m";
>> +                       else if (pidx == JH7110_STGCLK_CPU_BUS)
>> +                               parents[i].fw_name = "cpu_bus";
>> +                       else if (pidx == JH7110_STGCLK_HIFI4_AXI)
>> +                               parents[i].fw_name = "hifi4_axi";
>> +                       else if (pidx == JH7110_STGCLK_NOCSTG_BUS)
>> +                               parents[i].fw_name = "nocstg_bus";
>> +                       else if (pidx == JH7110_STGCLK_APB_BUS)
>> +                               parents[i].fw_name = "apb_bus";
> 
> Can this be an array lookup instead of a pile of conditions?
> 
> 	if (pidx < JH7110_STGCLK_END)
> 		...
> 	else
> 		parents[i].fw_name = fw_table[pidx - JH7110_STGCLK_END];
> 
> Or even better, don't use strings at all and just make the 'pidx' number
> (possibly minus the end constant) be the 'clocks' property index that
> you want.

It seen to be a good way that there uses an array.
Based on the another way, can I use the 'pidx' number to get the 'clock-names' property
to be the parent clock name?

> 
>> +               }
>> +
>> +               clk->hw.init = &init;
>> +               clk->idx = idx;
>> +               clk->max_div = max & JH71X0_CLK_DIV_MASK;
>> +
>> +               ret = devm_clk_hw_register(&pdev->dev, &clk->hw);
>> +               if (ret)
>> +                       return ret;
>> +       }
>> +
>> +       ret = devm_of_clk_add_hw_provider(&pdev->dev, jh7110_stgclk_get, priv);
>> +       if (ret)
>> +               return ret;
>> +
>> +       return jh7110_reset_controller_register(priv, "reset-stg", 2);
> 
> Is this also devm-ified?

No, it need to be freed actively. I will advise Hal Feng this.


Best regards,
Xingyu Wu