Re: [PATCH v4 3/3] phy: mediatek: tphy: add debugfs files

From: Vinod Koul
Date: Thu Nov 24 2022 - 12:47:17 EST


On 10-11-22, 21:27, 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@xxxxxxxxxxxx>
> ---
> 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/Kconfig | 5 +
> drivers/phy/mediatek/phy-mtk-tphy.c | 405 +++++++++++++++++++++++++++-
> 2 files changed, 409 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/phy/mediatek/Kconfig b/drivers/phy/mediatek/Kconfig
> index 3125ecb5d119..e9fdfe9f519f 100644
> --- a/drivers/phy/mediatek/Kconfig
> +++ b/drivers/phy/mediatek/Kconfig
> @@ -27,6 +27,11 @@ config PHY_MTK_TPHY
> multi-ports is first version, otherwise is second version,
> so you can easily distinguish them by banks layout.
>
> +config PHY_MTK_TPHY_DEBUGFS
> + bool "Add T-PHY Debugfs Files"
> + help
> + Say Y here to add debugfs files mainly for T-PHY HQA test.

Why do we need a config option for this, is debugfs config option not
sufficient?

> +
> config PHY_MTK_UFS
> tristate "MediaTek UFS M-PHY driver"
> depends on ARCH_MEDIATEK || COMPILE_TEST
> diff --git a/drivers/phy/mediatek/phy-mtk-tphy.c b/drivers/phy/mediatek/phy-mtk-tphy.c
> index e906a82791bd..f220a9a409bf 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_PHY_MTK_TPHY_DEBUGFS)
> +
> +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)

so are we writing to phy registers from userspace, why?

> +{
> + 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);

pls use
> +}
> +
> +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), phy_debug_root);
> +}
> +
> +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