[PATCH 05/11] scsi: ufs: core: Add debugfs entries for TX Equalization params

[Can Guo]

Add debugfs support for UFS TX Equalization feature to enable runtime
inspection of TX Equalization parameters. This provides visibility into
both host and device TX Equalization settings as well as TX Equalization
Training records for debugging and optimization purposes.

Signed-off-by: Can Guo <can.guo@xxxxxxxxxxxxxxxx>
---
 drivers/ufs/core/ufs-debugfs.c | 206 +++++++++++++++++++++++++++++++++
 include/ufs/ufshcd.h           |   2 +
 2 files changed, 208 insertions(+)

diff --git a/drivers/ufs/core/ufs-debugfs.c b/drivers/ufs/core/ufs-debugfs.c
index e3baed6c70bd..53deb8b2d1ea 100644
--- a/drivers/ufs/core/ufs-debugfs.c
+++ b/drivers/ufs/core/ufs-debugfs.c
@@ -209,6 +209,203 @@ static const struct ufs_debugfs_attr ufs_attrs[] = {
 	{ }
 };
 
+static int tx_eq_gear_get(void *data, u64 *val)
+{
+	struct ufs_hba *hba = data;
+
+	*val = (u64)hba->debugfs_tx_eq_gear;
+	return 0;
+}
+
+static int tx_eq_gear_set(void *data, u64 val)
+{
+	struct ufs_hba *hba = data;
+
+	if (val < UFS_HS_G1 || val >= UFS_HS_GEAR_MAX)
+		return -EINVAL;
+
+	hba->debugfs_tx_eq_gear = (u32)val;
+	return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(tx_eq_gear_fops, tx_eq_gear_get, tx_eq_gear_set, "%#llx\n");
+
+static int ufs_tx_eq_params_show(struct seq_file *s, void *data)
+{
+	struct ufs_debugfs_attr *attr = s->private;
+	struct ufs_hba *hba = hba_from_file(s->file);
+	struct ufshcd_tx_eq_settings *settings;
+	struct ufshcd_tx_eq_params *params;
+	u32 gear = hba->debugfs_tx_eq_gear;
+	u32 rate = hba->pwr_info.hs_rate;
+	u32 num_lanes;
+	int lane;
+
+	if (!ufshcd_is_tx_eq_supported(hba))
+		return -EOPNOTSUPP;
+
+	if (gear < UFS_HS_G1 || gear >= UFS_HS_GEAR_MAX) {
+		seq_printf(s, "Invalid gear selected: %u\n", gear);
+		return 0;
+	}
+
+	params = &hba->tx_eq_params[gear - 1];
+	if (!params->is_valid) {
+		seq_printf(s, "TX EQ params are invalid for HS-G%u, Rate-%s\n",
+			   gear, UFS_HS_RATE_STRING(rate));
+		return 0;
+	}
+
+	if (strcmp(attr->name, "host_tx_eq_params") == 0) {
+		settings = params->host;
+		num_lanes = params->tx_lanes;
+		seq_printf(s, "Host TX EQ PreShoot Cap: 0x%02x, DeEmphasis Cap: 0x%02x\n",
+			   hba->host_preshoot_cap, hba->host_deemphasis_cap);
+	} else if (strcmp(attr->name, "device_tx_eq_params") == 0) {
+		settings = params->device;
+		num_lanes = params->rx_lanes;
+		seq_printf(s, "Device TX EQ PreShoot Cap: 0x%02x, DeEmphasis Cap: 0x%02x\n",
+			   hba->device_preshoot_cap, hba->device_deemphasis_cap);
+	} else {
+		return -ENOENT;
+	}
+
+	seq_printf(s, "TX EQ setting for HS-G%u, Rate-%s:\n", gear,
+		   UFS_HS_RATE_STRING(rate));
+	for (lane = 0; lane < num_lanes; lane++)
+		seq_printf(s, "TX Lane %d - PreShoot: %d, DeEmphasis: %d, Pre-Coding %senabled\n",
+			   lane, settings[lane].preshoot,
+			   settings[lane].deemphasis,
+			   settings[lane].precode_en ? "" : "not ");
+
+	return 0;
+}
+
+static int ufs_tx_eq_params_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, ufs_tx_eq_params_show, inode->i_private);
+}
+
+static const struct file_operations ufs_tx_eq_params_fops = {
+	.owner		= THIS_MODULE,
+	.open		= ufs_tx_eq_params_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int ufs_tx_eqtr_record_show(struct seq_file *s, void *data)
+{
+	struct ufs_debugfs_attr *attr = s->private;
+	struct ufs_hba *hba = hba_from_file(s->file);
+	struct ufshcd_tx_eq_params *params;
+	unsigned long preshoot_bitmap, deemphasis_bitmap;
+	unsigned int preshoot, deemphasis;
+	u32 (*record)[TX_HS_NUM_PRESHOOT][TX_HS_NUM_DEEMPHASIS];
+	u32 gear = hba->debugfs_tx_eq_gear;
+	u32 rate = hba->pwr_info.hs_rate;
+	u32 num_lanes;
+	int lane;
+	char name[32];
+
+	if (!ufshcd_is_tx_eq_supported(hba))
+		return -EOPNOTSUPP;
+
+	if (gear < UFS_HS_G1 || gear >= UFS_HS_GEAR_MAX) {
+		seq_printf(s, "Invalid gear selected: %u\n", gear);
+		return 0;
+	}
+
+	params = &hba->tx_eq_params[gear - 1];
+	if (!params->is_valid) {
+		seq_printf(s, "TX EQ params are invalid for HS-G%u, Rate-%s\n",
+			   gear, UFS_HS_RATE_STRING(rate));
+		return 0;
+	}
+
+	if (!params->num_eqtr_records) {
+		seq_printf(s, "No TX EQTR records found for HS-G%u, Rate-%s.\n",
+			   gear, UFS_HS_RATE_STRING(rate));
+		return 0;
+	}
+
+	if (strcmp(attr->name, "host_tx_eqtr_record") == 0) {
+		record = params->host_eqtr_record;
+		preshoot_bitmap = (hba->host_preshoot_cap << 0x1) | 0x1;
+		deemphasis_bitmap = (hba->host_deemphasis_cap << 0x1) | 0x1;
+		num_lanes = params->tx_lanes;
+		snprintf(name, 32, "%s", "Host");
+	} else if (strcmp(attr->name, "device_tx_eqtr_record") == 0) {
+		record = params->device_eqtr_record;
+		preshoot_bitmap = (hba->device_preshoot_cap << 0x1) | 0x1;
+		deemphasis_bitmap = (hba->device_deemphasis_cap << 0x1) | 0x1;
+		num_lanes = params->rx_lanes;
+		snprintf(name, 32, "%s", "Device");
+	} else {
+		return -ENOENT;
+	}
+
+	seq_printf(s, "%s TX EQTR record summary -\n", name);
+	seq_printf(s, "Target Power Mode: HS-G%u, Rate-%s\n", gear,
+		   UFS_HS_RATE_STRING(rate));
+	seq_printf(s, "Number of records: %d\n", params->num_eqtr_records);
+	seq_printf(s, "Last record timestamp: %llu us\n",
+		   ktime_to_us(params->last_eqtr_ts));
+
+	for (lane = 0; lane < num_lanes; lane++) {
+		seq_printf(s, "\nTX Lane %d: %s\n", lane, "PreShoot\\DeEmphasis");
+		seq_puts(s, "\\");
+		/* Print DeEmphasis header as X-axis. */
+		for (deemphasis = 0; deemphasis < TX_HS_NUM_DEEMPHASIS; deemphasis++)
+			seq_printf(s, "%8d%s", deemphasis, " ");
+		seq_puts(s, "\n");
+		/* Print matrix rows with PreShoot as Y-axis. */
+		for (preshoot = 0; preshoot < TX_HS_NUM_PRESHOOT; preshoot++) {
+			seq_printf(s, "%d", preshoot);
+			for (deemphasis = 0; deemphasis < TX_HS_NUM_DEEMPHASIS; deemphasis++) {
+				if (test_bit(preshoot, &preshoot_bitmap) &&
+				    test_bit(deemphasis, &deemphasis_bitmap)) {
+					u32 fom = record[lane][preshoot][deemphasis];
+					u32 fom_val = fom & RX_FOM_VALUE_MASK;
+					bool precode_en = !!(fom & RX_FOM_PRECODING_EN_MASK);
+
+					if (fom == 0xFFFFFFFF)
+						seq_printf(s, "%8s%s", "-", " ");
+					else
+						seq_printf(s, "%8u%s", fom_val,
+							   precode_en ? "*" : " ");
+				} else {
+					seq_printf(s, "%8s%s", "x", " ");
+				}
+			}
+			seq_puts(s, "\n");
+		}
+	}
+
+	return 0;
+}
+
+static int ufs_tx_eqtr_record_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, ufs_tx_eqtr_record_show, inode->i_private);
+}
+
+static const struct file_operations ufs_tx_eqtr_record_fops = {
+	.owner		= THIS_MODULE,
+	.open		= ufs_tx_eqtr_record_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static const struct ufs_debugfs_attr ufs_tx_eq_attrs[] = {
+	{ "host_tx_eq_params", 0400, &ufs_tx_eq_params_fops },
+	{ "device_tx_eq_params", 0400, &ufs_tx_eq_params_fops },
+	{ "host_tx_eqtr_record", 0400, &ufs_tx_eqtr_record_fops },
+	{ "device_tx_eqtr_record", 0400, &ufs_tx_eqtr_record_fops },
+	{ }
+};
+
 void ufs_debugfs_hba_init(struct ufs_hba *hba)
 {
 	const struct ufs_debugfs_attr *attr;
@@ -230,6 +427,15 @@ void ufs_debugfs_hba_init(struct ufs_hba *hba)
 			    hba, &ee_usr_mask_fops);
 	debugfs_create_u32("exception_event_rate_limit_ms", 0600, hba->debugfs_root,
 			   &hba->debugfs_ee_rate_limit_ms);
+
+	if (!(hba->caps & UFSHCD_CAP_TX_EQUALIZATION))
+		return;
+	hba->debugfs_tx_eq_gear = UFS_HS_GEAR_MAX - 1;
+	debugfs_create_file("tx_eq_gear_sel", 0600, hba->debugfs_root, hba,
+			    &tx_eq_gear_fops);
+	for (attr = ufs_tx_eq_attrs; attr->name; attr++)
+		debugfs_create_file(attr->name, attr->mode, root, (void *)attr,
+				    attr->fops);
 }
 
 void ufs_debugfs_hba_exit(struct ufs_hba *hba)
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index 696db71d68bc..56455b137f10 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -1038,6 +1038,7 @@ enum ufshcd_mcq_opr {
  * @host_deemphasis_cap: host TX DeEmphasis capability
  * @device_preshoot_cap: device TX PreShoot capability
  * @device_deemphasis_cap: device TX DeEmphasis capability
+ * @debugfs_tx_eq_gear: used to select Gear for TX Equalization debugfs entries
  * @tx_eq_params: TX Equalization settings
  */
 struct ufs_hba {
@@ -1217,6 +1218,7 @@ struct ufs_hba {
 	u32 host_deemphasis_cap;
 	u32 device_preshoot_cap;
 	u32 device_deemphasis_cap;
+	u32 debugfs_tx_eq_gear;
 	struct ufshcd_tx_eq_params tx_eq_params[UFS_HS_GEAR_MAX - 1];
 };
 
-- 
2.34.1