[PATCH v8] phy: mediatek: tphy: add debugfs files

[PATCH v8] phy: mediatek: tphy: add debugfs files

[Chunfeng Yun]

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

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 */
 };
 
+#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

Re: [PATCH v8] phy: mediatek: tphy: add debugfs files

[Vinod Koul]

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

Re: [PATCH v8] phy: mediatek: tphy: add debugfs files

[Chunfeng Yun (云春峰)]

On Mon, 2023-02-13 at 16:21 +0800, chunfeng yun wrote:
> On Fri, 2023-02-10 at 21:01 +0530, Vinod Koul wrote:
> > 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
> 
> Sorry, I misunderstood you means
> > 
> > > 
> > > 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
> > 
> > >  
> 
> Ok, I'll do the following steps:
> 
> 0. put a struct dentry *debugfs in struct phy;
> 1. define a static struct dentry *phy_debugfs_root in phy-core.c,
> then
>    create a root directory (/sys/kernel/debug/phy/) for phy
> subsystem 
> in phy_core_init();
> 2. create directory for each phy under the root directory
> (/sys/kernel/debug/phy/);
>    this step has two ways:
>    A: create the directory @debugfs of struct phy in phy_create() by
> default;
>    B: provide some api for user to create/destory the directory
> @debugfs or others when need;
> 3. add private debugfs files in @debugfs of struct phy;
> 
> For the case in tphy driver, it provides some struct phy, the driver
> may want to create debugfs files which not belongs to any struct phy
> in
> the root directory (/sys/kernel/debug/phy/), then need provide a api.
> 
>    Do you have any suggestions?
>    Which way do you prefer to use in step 2?
> 
>    Thanks a lot;
> 
> > <skip>
> > > +
> > >  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
> > 
> > 

Re: [PATCH v8] phy: mediatek: tphy: add debugfs files

[Vinod Koul]

On 13-02-23, 08:22, Chunfeng Yun (云春峰) wrote:
> On Mon, 2023-02-13 at 16:21 +0800, chunfeng yun wrote:
> > On Fri, 2023-02-10 at 21:01 +0530, Vinod Koul wrote:
> > > 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
> > 
> > Sorry, I misunderstood you means
> > > 
> > > > 
> > > > 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
> > > 
> > > >  
> > 
> > Ok, I'll do the following steps:
> > 
> > 0. put a struct dentry *debugfs in struct phy;
> > 1. define a static struct dentry *phy_debugfs_root in phy-core.c,
> > then
> >    create a root directory (/sys/kernel/debug/phy/) for phy
> > subsystem 
> > in phy_core_init();
> > 2. create directory for each phy under the root directory
> > (/sys/kernel/debug/phy/);
> >    this step has two ways:
> >    A: create the directory @debugfs of struct phy in phy_create() by
> > default;

That sounds good to me

> >    B: provide some api for user to create/destory the directory
> > @debugfs or others when need;
> > 3. add private debugfs files in @debugfs of struct phy;
> > 
> > For the case in tphy driver, it provides some struct phy, the driver
> > may want to create debugfs files which not belongs to any struct phy
> > in
> > the root directory (/sys/kernel/debug/phy/), then need provide a api.
> > 
> >    Do you have any suggestions?
> >    Which way do you prefer to use in step 2?
> > 
> >    Thanks a lot;
> > 
> > > <skip>
> > > > +
> > > >  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

Re: [PATCH v8] phy: mediatek: tphy: add debugfs files

[Chunfeng Yun (云春峰)]

On Fri, 2023-02-10 at 21:01 +0530, Vinod Koul wrote:
> 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
Sorry, I misunderstood you means
> 
> > 
> > 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
> 
> >  
Ok, I'll do the following steps:

0. put a struct dentry *debugfs in struct phy;
1. define a static struct dentry *phy_debugfs_root in phy-core.c, then
   create a root directory (/sys/kernel/debug/phy/) for phy subsystem 
in phy_core_init();
2. create directory for each phy under the root directory
(/sys/kernel/debug/phy/);
   this step has two ways:
   A: create the directory @debugfs of struct phy in phy_create() by
default;
   B: provide some api for user to create/destory the directory
@debugfs or others when need;
3. add private debugfs files in @debugfs of struct phy;

For the case in tphy driver, it provides some struct phy, the driver
may want to create debugfs files which not belongs to any struct phy in
the root directory (/sys/kernel/debug/phy/), then need provide a api.

   Do you have any suggestions?
   Which way do you prefer to use in step 2?

   Thanks a lot;

> <skip>
> > +
> >  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
> 
>