Date:   Fri, 10 Feb 2023 21:01:09 +0530
From:   Vinod Koul <vkoul@kernel.org>
To:     Chunfeng Yun <chunfeng.yun@mediatek.com>
Cc:     Matthias Brugger <matthias.bgg@gmail.com>,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, linux-phy@lists.infradead.org,
        linux-kernel@vger.kernel.org, Eddie Hung <eddie.hung@mediatek.com>
Subject: Re: [PATCH v8] phy: mediatek: tphy: add debugfs files
Message-ID: <Y+ZjPYDEbC9iblsj@matsya>
References: <20230210085827.7970-1-chunfeng.yun@mediatek.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230210085827.7970-1-chunfeng.yun@mediatek.com>
Precedence: bulk

On 10-02-23, 16:58, Chunfeng Yun wrote:
> These debugfs files are mainly used to make eye diagram test easier,
> especially helpful to do HQA test for a new IC without efuse enabled.
> 
> Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> ---
> v8: abandon patch to create phy debug root file
>     /sys/kernel/debug/phy/ suggested by Vinod

Sorry that was not my suggestion

> 
> v6~v7: no changes
> 
> v5: using common debugfs config CONFIG_DEBUG_FS
> 
> v4: fix build warning of sometimes uninitialized variable
> 
> v3: fix typo of "debugfs" suggested by AngeloGioacchino
> 
> v2: add CONFIG_PHY_MTK_TPHY_DEBUGFS suggested by AngeloGioacchino
> ---
>  drivers/phy/mediatek/phy-mtk-tphy.c | 405 +++++++++++++++++++++++++++-
>  1 file changed, 404 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/phy/mediatek/phy-mtk-tphy.c b/drivers/phy/mediatek/phy-mtk-tphy.c
> index e906a82791bd..65a95c3726bf 100644
> --- a/drivers/phy/mediatek/phy-mtk-tphy.c
> +++ b/drivers/phy/mediatek/phy-mtk-tphy.c
> @@ -7,6 +7,7 @@
>  
>  #include <dt-bindings/phy/phy.h>
>  #include <linux/clk.h>
> +#include <linux/debugfs.h>
>  #include <linux/delay.h>
>  #include <linux/iopoll.h>
>  #include <linux/mfd/syscon.h>
> @@ -264,6 +265,8 @@
>  
>  #define TPHY_CLKS_CNT	2
>  
> +#define USER_BUF_LEN(count) min_t(size_t, 8, (count))
> +
>  enum mtk_phy_version {
>  	MTK_PHY_V1 = 1,
>  	MTK_PHY_V2,
> @@ -310,6 +313,7 @@ struct mtk_phy_instance {
>  	struct clk_bulk_data clks[TPHY_CLKS_CNT];
>  	u32 index;
>  	u32 type;
> +	struct dentry *dbgfs;
>  	struct regmap *type_sw;
>  	u32 type_sw_reg;
>  	u32 type_sw_index;
> @@ -332,10 +336,391 @@ struct mtk_tphy {
>  	const struct mtk_phy_pdata *pdata;
>  	struct mtk_phy_instance **phys;
>  	int nphys;
> +	struct dentry *dbgfs_root;
>  	int src_ref_clk; /* MHZ, reference clock for slew rate calibrate */
>  	int src_coef; /* coefficient for slew rate calibrate */
>  };

I asked the struct dentry *debugfs be part of struct phy. Debugfs would
be created by core but rather than exported, it should be populated in
phy and you can use it here in the driver

>  
> +#if IS_ENABLED(CONFIG_DEBUG_FS)
> +
> +enum u2_phy_params {
> +	U2P_EYE_VRT = 0,
> +	U2P_EYE_TERM,
> +	U2P_EFUSE_EN,
> +	U2P_EFUSE_INTR,
> +	U2P_DISCTH,
> +	U2P_PRE_EMPHASIS,
> +};
> +
> +enum u3_phy_params {
> +	U3P_EFUSE_EN = 0,
> +	U3P_EFUSE_INTR,
> +	U3P_EFUSE_TX_IMP,
> +	U3P_EFUSE_RX_IMP,
> +};
> +
> +static const char *const u2_phy_files[] = {
> +	[U2P_EYE_VRT] = "vrt",
> +	[U2P_EYE_TERM] = "term",
> +	[U2P_EFUSE_EN] = "efuse",
> +	[U2P_EFUSE_INTR] = "intr",
> +	[U2P_DISCTH] = "discth",
> +	[U2P_PRE_EMPHASIS] = "preemph",
> +};
> +
> +static const char *const u3_phy_files[] = {
> +	[U3P_EFUSE_EN] = "efuse",
> +	[U3P_EFUSE_INTR] = "intr",
> +	[U3P_EFUSE_TX_IMP] = "tx-imp",
> +	[U3P_EFUSE_RX_IMP] = "rx-imp",
> +};
> +
> +static int u2_phy_params_show(struct seq_file *sf, void *unused)
> +{
> +	struct mtk_phy_instance *inst = sf->private;
> +	const char *fname = file_dentry(sf->file)->d_iname;
> +	struct u2phy_banks *u2_banks = &inst->u2_banks;
> +	void __iomem *com = u2_banks->com;
> +	u32 max = 0;
> +	u32 tmp = 0;
> +	u32 val = 0;
> +	int ret;
> +
> +	ret = match_string(u2_phy_files, ARRAY_SIZE(u2_phy_files), fname);
> +	if (ret < 0)
> +		return ret;
> +
> +	switch (ret) {
> +	case U2P_EYE_VRT:
> +		tmp = readl(com + U3P_USBPHYACR1);
> +		val = FIELD_GET(PA1_RG_VRT_SEL, tmp);
> +		max = FIELD_MAX(PA1_RG_VRT_SEL);
> +		break;
> +
> +	case U2P_EYE_TERM:
> +		tmp = readl(com + U3P_USBPHYACR1);
> +		val = FIELD_GET(PA1_RG_TERM_SEL, tmp);
> +		max = FIELD_MAX(PA1_RG_TERM_SEL);
> +		break;
> +
> +	case U2P_EFUSE_EN:
> +		if (u2_banks->misc) {
> +			tmp = readl(u2_banks->misc + U3P_MISC_REG1);
> +			max = 1;
> +		}
> +
> +		val = !!(tmp & MR1_EFUSE_AUTO_LOAD_DIS);
> +		break;
> +
> +	case U2P_EFUSE_INTR:
> +		tmp = readl(com + U3P_USBPHYACR1);
> +		val = FIELD_GET(PA1_RG_INTR_CAL, tmp);
> +		max = FIELD_MAX(PA1_RG_INTR_CAL);
> +		break;
> +
> +	case U2P_DISCTH:
> +		tmp = readl(com + U3P_USBPHYACR6);
> +		val = FIELD_GET(PA6_RG_U2_DISCTH, tmp);
> +		max = FIELD_MAX(PA6_RG_U2_DISCTH);
> +		break;
> +
> +	case U2P_PRE_EMPHASIS:
> +		tmp = readl(com + U3P_USBPHYACR6);
> +		val = FIELD_GET(PA6_RG_U2_PRE_EMP, tmp);
> +		max = FIELD_MAX(PA6_RG_U2_PRE_EMP);
> +		break;
> +
> +	default:
> +		seq_printf(sf, "invalid, %d\n", ret);
> +		break;
> +	}
> +
> +	seq_printf(sf, "%s : %d [0, %d]\n", fname, val, max);
> +
> +	return 0;
> +}
> +
> +static int u2_phy_params_open(struct inode *inode, struct file *file)
> +{
> +	return single_open(file, u2_phy_params_show, inode->i_private);
> +}
> +
> +static ssize_t u2_phy_params_write(struct file *file, const char __user *ubuf,
> +				   size_t count, loff_t *ppos)
> +{
> +	const char *fname = file_dentry(file)->d_iname;
> +	struct seq_file *sf = file->private_data;
> +	struct mtk_phy_instance *inst = sf->private;
> +	struct u2phy_banks *u2_banks = &inst->u2_banks;
> +	void __iomem *com = u2_banks->com;
> +	ssize_t rc;
> +	u32 val;
> +	int ret;
> +
> +	rc = kstrtouint_from_user(ubuf, USER_BUF_LEN(count), 0, &val);
> +	if (rc)
> +		return rc;
> +
> +	ret = match_string(u2_phy_files, ARRAY_SIZE(u2_phy_files), fname);
> +	if (ret < 0)
> +		return (ssize_t)ret;
> +
> +	switch (ret) {
> +	case U2P_EYE_VRT:
> +		mtk_phy_update_field(com + U3P_USBPHYACR1, PA1_RG_VRT_SEL, val);
> +		break;
> +
> +	case U2P_EYE_TERM:
> +		mtk_phy_update_field(com + U3P_USBPHYACR1, PA1_RG_TERM_SEL, val);
> +		break;
> +
> +	case U2P_EFUSE_EN:
> +		if (u2_banks->misc)
> +			mtk_phy_update_field(u2_banks->misc + U3P_MISC_REG1,
> +					     MR1_EFUSE_AUTO_LOAD_DIS, !!val);
> +		break;
> +
> +	case U2P_EFUSE_INTR:
> +		mtk_phy_update_field(com + U3P_USBPHYACR1, PA1_RG_INTR_CAL, val);
> +		break;
> +
> +	case U2P_DISCTH:
> +		mtk_phy_update_field(com + U3P_USBPHYACR6, PA6_RG_U2_DISCTH, val);
> +		break;
> +
> +	case U2P_PRE_EMPHASIS:
> +		mtk_phy_update_field(com + U3P_USBPHYACR6, PA6_RG_U2_PRE_EMP, val);
> +		break;
> +
> +	default:
> +		break;
> +	}
> +
> +	return count;
> +}
> +
> +static const struct file_operations u2_phy_fops = {
> +	.open = u2_phy_params_open,
> +	.write = u2_phy_params_write,
> +	.read = seq_read,
> +	.llseek = seq_lseek,
> +	.release = single_release,
> +};
> +
> +static void u2_phy_dbgfs_files_create(struct mtk_phy_instance *inst)
> +{
> +	u32 count = ARRAY_SIZE(u2_phy_files);
> +	int i;
> +
> +	for (i = 0; i < count; i++)
> +		debugfs_create_file(u2_phy_files[i], 0644, inst->dbgfs, inst, &u2_phy_fops);
> +}
> +
> +static int u3_phy_params_show(struct seq_file *sf, void *unused)
> +{
> +	struct mtk_phy_instance *inst = sf->private;
> +	const char *fname = file_dentry(sf->file)->d_iname;
> +	struct u3phy_banks *u3_banks = &inst->u3_banks;
> +	u32 val = 0;
> +	u32 max = 0;
> +	u32 tmp;
> +	int ret;
> +
> +	ret = match_string(u3_phy_files, ARRAY_SIZE(u3_phy_files), fname);
> +	if (ret < 0)
> +		return ret;
> +
> +	switch (ret) {
> +	case U3P_EFUSE_EN:
> +		tmp = readl(u3_banks->phyd + U3P_U3_PHYD_RSV);
> +		val = !!(tmp & P3D_RG_EFUSE_AUTO_LOAD_DIS);
> +		max = 1;
> +		break;
> +
> +	case U3P_EFUSE_INTR:
> +		tmp = readl(u3_banks->phya + U3P_U3_PHYA_REG0);
> +		val = FIELD_GET(P3A_RG_IEXT_INTR, tmp);
> +		max = FIELD_MAX(P3A_RG_IEXT_INTR);
> +		break;
> +
> +	case U3P_EFUSE_TX_IMP:
> +		tmp = readl(u3_banks->phyd + U3P_U3_PHYD_IMPCAL0);
> +		val = FIELD_GET(P3D_RG_TX_IMPEL, tmp);
> +		max = FIELD_MAX(P3D_RG_TX_IMPEL);
> +		break;
> +
> +	case U3P_EFUSE_RX_IMP:
> +		tmp = readl(u3_banks->phyd + U3P_U3_PHYD_IMPCAL1);
> +		val = FIELD_GET(P3D_RG_RX_IMPEL, tmp);
> +		max = FIELD_MAX(P3D_RG_RX_IMPEL);
> +		break;
> +
> +	default:
> +		seq_printf(sf, "invalid, %d\n", ret);
> +		break;
> +	}
> +
> +	seq_printf(sf, "%s : %d [0, %d]\n", fname, val, max);
> +
> +	return 0;
> +}
> +
> +static int u3_phy_params_open(struct inode *inode, struct file *file)
> +{
> +	return single_open(file, u3_phy_params_show, inode->i_private);
> +}
> +
> +static ssize_t u3_phy_params_write(struct file *file, const char __user *ubuf,
> +				   size_t count, loff_t *ppos)
> +{
> +	const char *fname = file_dentry(file)->d_iname;
> +	struct seq_file *sf = file->private_data;
> +	struct mtk_phy_instance *inst = sf->private;
> +	struct u3phy_banks *u3_banks = &inst->u3_banks;
> +	void __iomem *phyd = u3_banks->phyd;
> +	ssize_t rc;
> +	u32 val;
> +	int ret;
> +
> +	rc = kstrtouint_from_user(ubuf, USER_BUF_LEN(count), 0, &val);
> +	if (rc)
> +		return rc;
> +
> +	ret = match_string(u3_phy_files, ARRAY_SIZE(u3_phy_files), fname);
> +	if (ret < 0)
> +		return (ssize_t)ret;
> +
> +	switch (ret) {
> +	case U3P_EFUSE_EN:
> +		mtk_phy_update_field(phyd + U3P_U3_PHYD_RSV,
> +				     P3D_RG_EFUSE_AUTO_LOAD_DIS, !!val);
> +		break;
> +
> +	case U3P_EFUSE_INTR:
> +		mtk_phy_update_field(u3_banks->phya + U3P_U3_PHYA_REG0, P3A_RG_IEXT_INTR, val);
> +		break;
> +
> +	case U3P_EFUSE_TX_IMP:
> +		mtk_phy_update_field(phyd + U3P_U3_PHYD_IMPCAL0, P3D_RG_TX_IMPEL, val);
> +		mtk_phy_set_bits(phyd + U3P_U3_PHYD_IMPCAL0, P3D_RG_FORCE_TX_IMPEL);
> +		break;
> +
> +	case U3P_EFUSE_RX_IMP:
> +		mtk_phy_update_field(phyd + U3P_U3_PHYD_IMPCAL1, P3D_RG_RX_IMPEL, val);
> +		mtk_phy_set_bits(phyd + U3P_U3_PHYD_IMPCAL1, P3D_RG_FORCE_RX_IMPEL);
> +		break;
> +
> +	default:
> +		break;
> +	}
> +
> +	return count;
> +}
> +
> +static const struct file_operations u3_phy_fops = {
> +	.open = u3_phy_params_open,
> +	.write = u3_phy_params_write,
> +	.read = seq_read,
> +	.llseek = seq_lseek,
> +	.release = single_release,
> +};
> +
> +static void u3_phy_dbgfs_files_create(struct mtk_phy_instance *inst)
> +{
> +	u32 count = ARRAY_SIZE(u3_phy_files);
> +	int i;
> +
> +	for (i = 0; i < count; i++)
> +		debugfs_create_file(u3_phy_files[i], 0644, inst->dbgfs, inst, &u3_phy_fops);
> +}
> +
> +static int tphy_type_show(struct seq_file *sf, void *unused)
> +{
> +	struct mtk_phy_instance *inst = sf->private;
> +	const char *type;
> +
> +	switch (inst->type) {
> +	case PHY_TYPE_USB2:
> +		type = "USB2";
> +		break;
> +	case PHY_TYPE_USB3:
> +		type = "USB3";
> +		break;
> +	case PHY_TYPE_PCIE:
> +		type = "PCIe";
> +		break;
> +	case PHY_TYPE_SGMII:
> +		type = "SGMII";
> +		break;
> +	case PHY_TYPE_SATA:
> +		type = "SATA";
> +		break;
> +	default:
> +		type = "";
> +	}
> +
> +	seq_printf(sf, "%s\n", type);
> +
> +	return 0;
> +}
> +
> +DEFINE_SHOW_ATTRIBUTE(tphy_type);
> +
> +static void tphy_debugfs_init(struct mtk_tphy *tphy, struct mtk_phy_instance *inst)
> +{
> +	char name[16];
> +
> +	snprintf(name, sizeof(name) - 1, "phy.%d", inst->index);
> +	inst->dbgfs = debugfs_create_dir(name, tphy->dbgfs_root);
> +
> +	debugfs_create_file("type", 0444, inst->dbgfs, inst, &tphy_type_fops);
> +
> +	switch (inst->type) {
> +	case PHY_TYPE_USB2:
> +		u2_phy_dbgfs_files_create(inst);
> +		break;
> +	case PHY_TYPE_USB3:
> +	case PHY_TYPE_PCIE:
> +		u3_phy_dbgfs_files_create(inst);
> +		break;
> +	default:
> +		break;
> +	}
> +}
> +
> +static void tphy_debugfs_exit(struct mtk_phy_instance *inst)
> +{
> +	debugfs_remove_recursive(inst->dbgfs);
> +	inst->dbgfs = NULL;
> +}
> +
> +static void tphy_debugfs_root_create(struct mtk_tphy *tphy)
> +{
> +	tphy->dbgfs_root = debugfs_create_dir(dev_name(tphy->dev), NULL);
> +}
> +
> +static void tphy_debugfs_root_remove(struct mtk_tphy *tphy)
> +{
> +	debugfs_remove_recursive(tphy->dbgfs_root);
> +	tphy->dbgfs_root = NULL;
> +}
> +
> +#else
> +
> +static void tphy_debugfs_init(struct mtk_tphy *tphy, struct mtk_phy_instance *inst)
> +{}
> +
> +static void tphy_debugfs_exit(struct mtk_phy_instance *inst)
> +{}
> +
> +static void tphy_debugfs_root_create(struct mtk_tphy *tphy)
> +{}
> +
> +static void tphy_debugfs_root_remove(struct mtk_tphy *tphy)
> +{}
> +
> +#endif
> +
>  static void hs_slew_rate_calibrate(struct mtk_tphy *tphy,
>  	struct mtk_phy_instance *instance)
>  {
> @@ -1032,6 +1417,8 @@ static int mtk_phy_init(struct phy *phy)
>  		return -EINVAL;
>  	}
>  
> +	tphy_debugfs_init(tphy, instance);
> +
>  	return 0;
>  }
>  
> @@ -1068,6 +1455,8 @@ static int mtk_phy_exit(struct phy *phy)
>  	struct mtk_phy_instance *instance = phy_get_drvdata(phy);
>  	struct mtk_tphy *tphy = dev_get_drvdata(phy->dev.parent);
>  
> +	tphy_debugfs_exit(instance);
> +
>  	if (instance->type == PHY_TYPE_USB2)
>  		u2_phy_instance_exit(tphy, instance);
>  
> @@ -1295,15 +1684,29 @@ static int mtk_tphy_probe(struct platform_device *pdev)
>  	}
>  
>  	provider = devm_of_phy_provider_register(dev, mtk_phy_xlate);
> +	if (IS_ERR(provider))
> +		return dev_err_probe(dev, PTR_ERR(provider), "probe failed\n");
> +
> +	tphy_debugfs_root_create(tphy);
> +	return 0;
>  
> -	return PTR_ERR_OR_ZERO(provider);
>  put_child:
>  	of_node_put(child_np);
>  	return retval;
>  }
>  
> +static int mtk_tphy_remove(struct platform_device *pdev)
> +{
> +	struct mtk_tphy *tphy;
> +
> +	tphy = platform_get_drvdata(pdev);
> +	tphy_debugfs_root_remove(tphy);
> +	return 0;
> +}
> +
>  static struct platform_driver mtk_tphy_driver = {
>  	.probe		= mtk_tphy_probe,
> +	.remove		= mtk_tphy_remove,
>  	.driver		= {
>  		.name	= "mtk-tphy",
>  		.of_match_table = mtk_tphy_id_table,
> -- 
> 2.18.0

-- 
~Vinod