From: Rene Sapiens <rene.sapiens@xxxxxxxxx>
Add optional extended voltage offset range support for software and
hardware margining as defined by the USB4 specification.
If supported, it can be enabled like below:
# cd /sys/kernel/debug/thunderbolt/ROUTER/portX/margining/
# echo Y > optional_voltage_offset
Signed-off-by: Rene Sapiens <rene.sapiens@xxxxxxxxx>
Co-developed-by: R Kannappan <r.kannappan@xxxxxxxxx>
Signed-off-by: R Kannappan <r.kannappan@xxxxxxxxx>
Co-developed-by: Aapo Vienamo <aapo.vienamo@xxxxxxxxxxxxxxx>
Signed-off-by: Aapo Vienamo <aapo.vienamo@xxxxxxxxxxxxxxx>
Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
---
drivers/thunderbolt/debugfs.c | 74 +++++++++++++++++++++++++++++++++++
drivers/thunderbolt/sb_regs.h | 5 +++
drivers/thunderbolt/tb.h | 2 +
drivers/thunderbolt/usb4.c | 4 ++
4 files changed, 85 insertions(+)
diff --git a/drivers/thunderbolt/debugfs.c b/drivers/thunderbolt/debugfs.c
index 5d1588baea6a..9defa69ef3a7 100644
--- a/drivers/thunderbolt/debugfs.c
+++ b/drivers/thunderbolt/debugfs.c
@@ -394,8 +394,12 @@ static ssize_t retimer_sb_regs_write(struct file *file,
* @ber_level: Current BER level contour value
* @voltage_steps: Number of mandatory voltage steps
* @max_voltage_offset: Maximum mandatory voltage offset (in mV)
+ * @voltage_steps_optional_range: Number of voltage steps for optional range
+ * @max_voltage_offset_optional_range: Maximum voltage offset for the optional
+ * range (in mV).
* @time_steps: Number of time margin steps
* @max_time_offset: Maximum time margin offset (in mUI)
+ * @optional_voltage_offset_range: Enable optional extended voltage range
* @software: %true if software margining is used instead of hardware
* @time: %true if time margining is used instead of voltage
* @right_high: %false if left/low margin test is performed, %true if
@@ -414,8 +418,11 @@ struct tb_margining {
unsigned int ber_level;
unsigned int voltage_steps;
unsigned int max_voltage_offset;
+ unsigned int voltage_steps_optional_range;
+ unsigned int max_voltage_offset_optional_range;
unsigned int time_steps;
unsigned int max_time_offset;
+ bool optional_voltage_offset_range;
bool software;
bool time;
bool right_high;
@@ -454,6 +461,12 @@ independent_time_margins(const struct tb_margining *margining)
return FIELD_GET(USB4_MARGIN_CAP_1_TIME_INDP_MASK, margining->caps[1]);
}
+static bool
+supports_optional_voltage_offset_range(const struct tb_margining *margining)
+{
+ return margining->caps[0] & USB4_MARGIN_CAP_0_OPT_VOLTAGE_SUPPORT;
+}
+
static ssize_t
margining_ber_level_write(struct file *file, const char __user *user_buf,
size_t count, loff_t *ppos)
@@ -553,6 +566,14 @@ static int margining_caps_show(struct seq_file *s, void *not_used)
margining->voltage_steps);
seq_printf(s, "# maximum voltage offset: %u mV\n",
margining->max_voltage_offset);
+ seq_printf(s, "# optional voltage offset range support: %s\n",
+ str_yes_no(supports_optional_voltage_offset_range(margining)));
+ if (supports_optional_voltage_offset_range(margining)) {
+ seq_printf(s, "# voltage margin steps, optional range: %u\n",
+ margining->voltage_steps_optional_range);
+ seq_printf(s, "# maximum voltage offset, optional range: %u mV\n",
+ margining->max_voltage_offset_optional_range);
+ }
switch (independent_voltage_margins(margining)) {
case USB4_MARGIN_CAP_0_VOLTAGE_MIN:
@@ -667,6 +688,42 @@ static int margining_lanes_show(struct seq_file *s, void *not_used)
}
DEBUGFS_ATTR_RW(margining_lanes);
+static ssize_t
+margining_optional_voltage_offset_write(struct file *file,
+ const char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ struct seq_file *s = file->private_data;
+ struct tb_margining *margining = s->private;
+ struct tb *tb = margining->port->sw->tb;
+ bool val;
+ int ret;
+
+ ret = kstrtobool_from_user(user_buf, count, &val);
+ if (ret)
+ return ret;
+
+ scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
+ margining->optional_voltage_offset_range = val;
+ }
+
+ return count;
+}
+
+static int margining_optional_voltage_offset_show(struct seq_file *s,
+ void *not_used)
+{
+ struct tb_margining *margining = s->private;
+ struct tb *tb = margining->port->sw->tb;
+
+ scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
+ seq_printf(s, "%u\n", margining->optional_voltage_offset_range);
+ }
+
+ return 0;
+}
+DEBUGFS_ATTR_RW(margining_optional_voltage_offset);
+
static ssize_t margining_mode_write(struct file *file,
const char __user *user_buf,
size_t count, loff_t *ppos)
@@ -785,6 +842,7 @@ static int margining_run_write(void *data, u64 val)
.lanes = margining->lanes,
.time = margining->time,
.right_high = margining->right_high,
+ .optional_voltage_offset_range = margining->optional_voltage_offset_range,
};
tb_port_dbg(port,
@@ -806,6 +864,7 @@ static int margining_run_write(void *data, u64 val)
.lanes = margining->lanes,
.time = margining->time,
.right_high = margining->right_high,
+ .optional_voltage_offset_range = margining->optional_voltage_offset_range,
};
/* Clear the results */
@@ -865,6 +924,8 @@ static void voltage_margin_show(struct seq_file *s,
if (val & USB4_MARGIN_HW_RES_1_EXCEEDS)
seq_puts(s, " exceeds maximum");
seq_puts(s, "\n");
+ if (margining->optional_voltage_offset_range)
+ seq_puts(s, " optional voltage offset range enabled\n");
}
static void time_margin_show(struct seq_file *s,
@@ -1104,6 +1165,15 @@ static struct tb_margining *margining_alloc(struct tb_port *port,
val = FIELD_GET(USB4_MARGIN_CAP_0_MAX_VOLTAGE_OFFSET_MASK, margining->caps[0]);
margining->max_voltage_offset = 74 + val * 2;
+ if (supports_optional_voltage_offset_range(margining)) {
+ val = FIELD_GET(USB4_MARGIN_CAP_0_VOLT_STEPS_OPT_MASK,
+ margining->caps[0]);
+ margining->voltage_steps_optional_range = val;
+ val = FIELD_GET(USB4_MARGIN_CAP_1_MAX_VOLT_OFS_OPT_MASK,
+ margining->caps[1]);
+ margining->max_voltage_offset_optional_range = 74 + val * 2;
+ }
+
if (supports_time(margining)) {
val = FIELD_GET(USB4_MARGIN_CAP_1_TIME_STEPS_MASK, margining->caps[1]);
margining->time_steps = val;
@@ -1140,6 +1210,10 @@ static struct tb_margining *margining_alloc(struct tb_port *port,
independent_time_margins(margining) == USB4_MARGIN_CAP_1_TIME_LR))
debugfs_create_file("margin", 0600, dir, margining,
&margining_margin_fops);
+
+ if (supports_optional_voltage_offset_range(margining))
+ debugfs_create_file("optional_voltage_offset", DEBUGFS_MODE, dir, margining,
+ &margining_optional_voltage_offset_fops);
return margining;
}
diff --git a/drivers/thunderbolt/sb_regs.h b/drivers/thunderbolt/sb_regs.h
index 86e80aa297f7..8bff0740222c 100644
--- a/drivers/thunderbolt/sb_regs.h
+++ b/drivers/thunderbolt/sb_regs.h
@@ -57,6 +57,9 @@ enum usb4_sb_opcode {
#define USB4_MARGIN_CAP_0_TIME BIT(5)
#define USB4_MARGIN_CAP_0_VOLTAGE_STEPS_MASK GENMASK(12, 6)
#define USB4_MARGIN_CAP_0_MAX_VOLTAGE_OFFSET_MASK GENMASK(18, 13)
+#define USB4_MARGIN_CAP_0_OPT_VOLTAGE_SUPPORT BIT(19)
+#define USB4_MARGIN_CAP_0_VOLT_STEPS_OPT_MASK GENMASK(26, 20)
+#define USB4_MARGIN_CAP_1_MAX_VOLT_OFS_OPT_MASK GENMASK(7, 0)
#define USB4_MARGIN_CAP_1_TIME_DESTR BIT(8)
#define USB4_MARGIN_CAP_1_TIME_INDP_MASK GENMASK(10, 9)
#define USB4_MARGIN_CAP_1_TIME_MIN 0x0
@@ -72,6 +75,7 @@ enum usb4_sb_opcode {
#define USB4_MARGIN_HW_RH BIT(4)
#define USB4_MARGIN_HW_BER_MASK GENMASK(9, 5)
#define USB4_MARGIN_HW_BER_SHIFT 5
+#define USB4_MARGIN_HW_OPT_VOLTAGE BIT(10)
/* Applicable to all margin values */
#define USB4_MARGIN_HW_RES_1_MARGIN_MASK GENMASK(6, 0)
@@ -84,6 +88,7 @@ enum usb4_sb_opcode {
/* USB4_SB_OPCODE_RUN_SW_LANE_MARGINING */
#define USB4_MARGIN_SW_TIME BIT(3)
#define USB4_MARGIN_SW_RH BIT(4)
+#define USB4_MARGIN_SW_OPT_VOLTAGE BIT(5)
#define USB4_MARGIN_SW_COUNTER_MASK GENMASK(14, 13)
#endif
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 89ea66f885a4..262c333924b8 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -1372,6 +1372,7 @@ enum usb4_margin_sw_error_counter {
* @error_counter: Error counter operation for software margining
* @ber_level: Current BER level contour value
* @lanes: %0, %1 or %7 (all)
+ * @optional_voltage_offset_range: Enable optional extended voltage range
* @right_high: %false if left/low margin test is performed, %true if right/high
* @time: %true if time margining is used instead of voltage
*/
@@ -1379,6 +1380,7 @@ struct usb4_port_margining_params {
enum usb4_margin_sw_error_counter error_counter;
u32 ber_level;
u32 lanes;
+ bool optional_voltage_offset_range;
bool right_high;
bool time;
};
diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c
index cb51cafcf20c..a2f81e17ad8d 100644
--- a/drivers/thunderbolt/usb4.c
+++ b/drivers/thunderbolt/usb4.c
@@ -1676,6 +1676,8 @@ int usb4_port_hw_margin(struct tb_port *port, enum usb4_sb_target target,
val |= USB4_MARGIN_HW_RH;
if (params->ber_level)
val |= FIELD_PREP(USB4_MARGIN_HW_BER_MASK, params->ber_level);
+ if (params->optional_voltage_offset_range)
+ val |= USB4_MARGIN_HW_OPT_VOLTAGE;
ret = usb4_port_sb_write(port, target, index, USB4_SB_METADATA, &val,
sizeof(val));
@@ -1716,6 +1718,8 @@ int usb4_port_sw_margin(struct tb_port *port, enum usb4_sb_target target,
val = params->lanes;
if (params->time)
val |= USB4_MARGIN_SW_TIME;
+ if (params->optional_voltage_offset_range)
+ val |= USB4_MARGIN_SW_OPT_VOLTAGE;
if (params->right_high)
val |= USB4_MARGIN_SW_RH;
val |= FIELD_PREP(USB4_MARGIN_SW_COUNTER_MASK, params->error_counter);
--
2.43.0
