Re: [PATCH 3/3] phy: zynqmp: Add debugfs support

From: Vinod Koul <vkoul@kernel.org>
To: Sean Anderson <sean.anderson@linux.dev>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	linux-phy@lists.infradead.org, linux-kernel@vger.kernel.org,
	Michal Simek <michal.simek@amd.com>,
	linux-arm-kernel@lists.infradead.org,
	Kishon Vijay Abraham I <kishon@kernel.org>
Subject: Re: [PATCH 3/3] phy: zynqmp: Add debugfs support
Date: Sat, 4 May 2024 17:28:58 +0530	[thread overview]
Message-ID: <ZjYjAjPlM5ClOGa4@matsya> (raw)
In-Reply-To: <20240422185803.3575319-4-sean.anderson@linux.dev>

On 22-04-24, 14:58, Sean Anderson wrote:
> Add support for printing some basic status information to debugfs. This
> is helpful when debugging phy consumers to make sure they are configuring
> the phy appropriately.
> 
> Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
> ---
> 
>  drivers/phy/xilinx/phy-zynqmp.c | 54 +++++++++++++++++++++++++++++++++
>  1 file changed, 54 insertions(+)
> 
> diff --git a/drivers/phy/xilinx/phy-zynqmp.c b/drivers/phy/xilinx/phy-zynqmp.c
> index 08c88dcd7799..e2e86943e9f3 100644
> --- a/drivers/phy/xilinx/phy-zynqmp.c
> +++ b/drivers/phy/xilinx/phy-zynqmp.c
> @@ -13,6 +13,7 @@
>   */
>  
>  #include <linux/clk.h>
> +#include <linux/debugfs.h>
>  #include <linux/delay.h>
>  #include <linux/io.h>
>  #include <linux/kernel.h>
> @@ -122,6 +123,15 @@
>  #define ICM_PROTOCOL_DP			0x4
>  #define ICM_PROTOCOL_SGMII		0x5
>  
> +static const char *const xpsgtr_icm_str[] = {
> +	[ICM_PROTOCOL_PD] = "powered down",
> +	[ICM_PROTOCOL_PCIE] = "PCIe",
> +	[ICM_PROTOCOL_SATA] = "SATA",
> +	[ICM_PROTOCOL_USB] = "USB",
> +	[ICM_PROTOCOL_DP] = "DisplayPort",
> +	[ICM_PROTOCOL_SGMII] = "SGMII",
> +};
> +
>  /* Test Mode common reset control  parameters */
>  #define TM_CMN_RST			0x10018
>  #define TM_CMN_RST_EN			0x1
> @@ -768,6 +778,48 @@ static struct phy *xpsgtr_xlate(struct device *dev,
>  	return ERR_PTR(-EINVAL);
>  }
>  
> +/*
> + * DebugFS
> + */
> +
> +static int xpsgtr_status_read(struct seq_file *seq, void *data)
> +{
> +	struct xpsgtr_phy *gtr_phy = seq->private;
> +	struct clk *clk;
> +	u32 pll_status;
> +
> +	mutex_lock(&gtr_phy->phy->mutex);
> +	pll_status = xpsgtr_read_phy(gtr_phy, L0_PLL_STATUS_READ_1);
> +	clk = gtr_phy->dev->clk[gtr_phy->refclk];
> +
> +	seq_printf(seq, "Lane:            %u\n", gtr_phy->lane);
> +	seq_printf(seq, "Protocol:        %s\n",
> +		   xpsgtr_icm_str[gtr_phy->protocol]);
> +	seq_printf(seq, "Instance:        %u\n", gtr_phy->instance);
> +	seq_printf(seq, "Reference clock: %u (%pC)\n", gtr_phy->refclk, clk);
> +	seq_printf(seq, "Reference rate:  %lu\n", clk_get_rate(clk));
> +	seq_printf(seq, "PLL locked:      %s\n",
> +		   pll_status & PLL_STATUS_LOCKED ? "yes" : "no");
> +
> +	mutex_unlock(&gtr_phy->phy->mutex);
> +	return 0;
> +}
> +
> +static int xpsgtr_status_open(struct inode *inode, struct file *f)
> +{
> +	struct xpsgtr_phy *gtr_phy = inode->i_private;
> +
> +	return single_open(f, xpsgtr_status_read, gtr_phy);
> +}
> +
> +static const struct file_operations xpsgtr_status_ops = {
> +	.owner = THIS_MODULE,
> +	.open = xpsgtr_status_open,
> +	.release = single_release,
> +	.read = seq_read,
> +	.llseek = seq_lseek
> +};

There are debugfs simple helpers which should help you avoid all this
open coding and just have the read call

> +
>  /*
>   * Power Management
>   */
> @@ -917,6 +969,8 @@ static int xpsgtr_probe(struct platform_device *pdev)
>  
>  		gtr_phy->phy = phy;
>  		phy_set_drvdata(phy, gtr_phy);
> +		debugfs_create_file("status", 0444, phy->debugfs, gtr_phy,
> +				    &xpsgtr_status_ops);

generic status does not make sense, how about device-name-status

-- 
~Vinod

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