Re: [PATCH V2 12/21] cpufreq: tegra124: do not handle the CPU rail

From: Jon Hunter <jonathanh@nvidia.com>
To: Joseph Lo <josephl@nvidia.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	 Peter De Schrijver <pdeschrijver@nvidia.com>
Cc: linux-tegra@vger.kernel.org,
	Viresh Kumar <viresh.kumar@linaro.org>,
	linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-pm@vger.kernel.org
Subject: Re: [PATCH V2 12/21] cpufreq: tegra124: do not handle the CPU rail
Date: Thu, 13 Dec 2018 12:55:29 +0000	[thread overview]
Message-ID: <83b2b2cd-7db5-5a5d-1c9e-9fe70afd6b4a@nvidia.com> (raw)
In-Reply-To: <20181213093438.29621-13-josephl@nvidia.com>


On 13/12/2018 09:34, Joseph Lo wrote:
> The Tegra124 cpufreq driver has no information to handle the Vdd-CPU
> rail. So this driver shouldn't handle for the CPU clock switching from
> DFLL to other PLL clocks. It was designed to work on DFLL clock only,
> which handle the frequency/voltage scaling in the background.
> 
> This patch removes the driver dependency of the CPU rail, as well as not
> allow it to be built as a module and remove the removal function. So it
> can keep working on DFLL clock.
> 
> Cc: Viresh Kumar <viresh.kumar@linaro.org>
> Cc: linux-pm@vger.kernel.org
> Signed-off-by: Joseph Lo <josephl@nvidia.com>
> ---
> *V2:
>  - update the commit message since we change the driver not able to be
>  built as a module and remove the removal function in V2
> ---
>  drivers/cpufreq/Kconfig.arm        |  4 +--
>  drivers/cpufreq/tegra124-cpufreq.c | 41 ++----------------------------
>  2 files changed, 4 insertions(+), 41 deletions(-)
> 
> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
> index 4e1131ef85ae..1d83b6e81222 100644
> --- a/drivers/cpufreq/Kconfig.arm
> +++ b/drivers/cpufreq/Kconfig.arm
> @@ -261,8 +261,8 @@ config ARM_TEGRA20_CPUFREQ
>  	  This adds the CPUFreq driver support for Tegra20 SOCs.
>  
>  config ARM_TEGRA124_CPUFREQ
> -	tristate "Tegra124 CPUFreq support"
> -	depends on ARCH_TEGRA && CPUFREQ_DT && REGULATOR
> +	bool "Tegra124 CPUFreq support"
> +	depends on ARCH_TEGRA && CPUFREQ_DT
>  	default y
>  	help
>  	  This adds the CPUFreq driver support for Tegra124 SOCs.
> diff --git a/drivers/cpufreq/tegra124-cpufreq.c b/drivers/cpufreq/tegra124-cpufreq.c
> index 43530254201a..a1bfde0a7950 100644
> --- a/drivers/cpufreq/tegra124-cpufreq.c
> +++ b/drivers/cpufreq/tegra124-cpufreq.c
> @@ -22,11 +22,9 @@
>  #include <linux/of.h>
>  #include <linux/platform_device.h>
>  #include <linux/pm_opp.h>
> -#include <linux/regulator/consumer.h>
>  #include <linux/types.h>
>  
>  struct tegra124_cpufreq_priv {
> -	struct regulator *vdd_cpu_reg;
>  	struct clk *cpu_clk;
>  	struct clk *pllp_clk;
>  	struct clk *pllx_clk;
> @@ -60,14 +58,6 @@ static int tegra124_cpu_switch_to_dfll(struct tegra124_cpufreq_priv *priv)
>  	return ret;
>  }
>  
> -static void tegra124_cpu_switch_to_pllx(struct tegra124_cpufreq_priv *priv)
> -{
> -	clk_set_parent(priv->cpu_clk, priv->pllp_clk);
> -	clk_disable_unprepare(priv->dfll_clk);
> -	regulator_sync_voltage(priv->vdd_cpu_reg);
> -	clk_set_parent(priv->cpu_clk, priv->pllx_clk);
> -}
> -
>  static int tegra124_cpufreq_probe(struct platform_device *pdev)
>  {
>  	struct tegra124_cpufreq_priv *priv;
> @@ -88,16 +78,10 @@ static int tegra124_cpufreq_probe(struct platform_device *pdev)
>  	if (!np)
>  		return -ENODEV;
>  
> -	priv->vdd_cpu_reg = regulator_get(cpu_dev, "vdd-cpu");
> -	if (IS_ERR(priv->vdd_cpu_reg)) {
> -		ret = PTR_ERR(priv->vdd_cpu_reg);
> -		goto out_put_np;
> -	}
> -
>  	priv->cpu_clk = of_clk_get_by_name(np, "cpu_g");
>  	if (IS_ERR(priv->cpu_clk)) {
>  		ret = PTR_ERR(priv->cpu_clk);
> -		goto out_put_vdd_cpu_reg;
> +		goto out_put_np;
>  	}
>  
>  	priv->dfll_clk = of_clk_get_by_name(np, "dfll");
> @@ -129,15 +113,13 @@ static int tegra124_cpufreq_probe(struct platform_device *pdev)
>  		platform_device_register_full(&cpufreq_dt_devinfo);
>  	if (IS_ERR(priv->cpufreq_dt_pdev)) {
>  		ret = PTR_ERR(priv->cpufreq_dt_pdev);
> -		goto out_switch_to_pllx;
> +		goto out_put_pllp_clk;
>  	}
>  
>  	platform_set_drvdata(pdev, priv);
>  
>  	return 0;
>  
> -out_switch_to_pllx:
> -	tegra124_cpu_switch_to_pllx(priv);
>  out_put_pllp_clk:
>  	clk_put(priv->pllp_clk);
>  out_put_pllx_clk:
> @@ -146,34 +128,15 @@ static int tegra124_cpufreq_probe(struct platform_device *pdev)
>  	clk_put(priv->dfll_clk);
>  out_put_cpu_clk:
>  	clk_put(priv->cpu_clk);
> -out_put_vdd_cpu_reg:
> -	regulator_put(priv->vdd_cpu_reg);
>  out_put_np:
>  	of_node_put(np);
>  
>  	return ret;
>  }
>  
> -static int tegra124_cpufreq_remove(struct platform_device *pdev)
> -{
> -	struct tegra124_cpufreq_priv *priv = platform_get_drvdata(pdev);
> -
> -	platform_device_unregister(priv->cpufreq_dt_pdev);
> -	tegra124_cpu_switch_to_pllx(priv);
> -
> -	clk_put(priv->pllp_clk);
> -	clk_put(priv->pllx_clk);
> -	clk_put(priv->dfll_clk);
> -	clk_put(priv->cpu_clk);
> -	regulator_put(priv->vdd_cpu_reg);
> -
> -	return 0;
> -}
> -
>  static struct platform_driver tegra124_cpufreq_platdrv = {
>  	.driver.name	= "cpufreq-tegra124",
>  	.probe		= tegra124_cpufreq_probe,
> -	.remove		= tegra124_cpufreq_remove,
>  };
>  
>  static int __init tegra_cpufreq_init(void)
> 

Acked-by: Jon Hunter <jonathanh@nvidia.com>

Cheers
Jon

-- 
nvpublic

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