thunderbolt: Move usb4_switch_wait_for_bit() to switch.c

Currently usb4_switch_wait_for_bit() used only in usb4.c Moving to
switch.c to call it from other files. Also change the prefix to "tb_"
to follow to the naming convention.

Signed-off-by: Gil Fine <gil.fine@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index 8e232ce615e9..c242a027698d 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -1457,6 +1457,40 @@ int tb_switch_reset(struct tb_switch *sw)
 	return res.err;
 }
 
+/**
+ * tb_switch_wait_for_bit() - Wait for specified value of bits in offset
+ * @sw: Router to read the offset value from
+ * @offset: Offset in the router config space to read from
+ * @bit: Bit mask in the offset to wait for
+ * @value: Value of the bits to wait for
+ * @timeout_msec: Timeout in ms how long to wait
+ *
+ * Wait till the specified bits in specified offset reach specified value.
+ * Returns %0 in case of success, %-ETIMEDOUT if the @value was not reached
+ * within the given timeout or a negative errno in case of failure.
+ */
+int tb_switch_wait_for_bit(struct tb_switch *sw, u32 offset, u32 bit,
+			   u32 value, int timeout_msec)
+{
+	ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
+
+	do {
+		u32 val;
+		int ret;
+
+		ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, offset, 1);
+		if (ret)
+			return ret;
+
+		if ((val & bit) == value)
+			return 0;
+
+		usleep_range(50, 100);
+	} while (ktime_before(ktime_get(), timeout));
+
+	return -ETIMEDOUT;
+}
+
 /*
  * tb_plug_events_active() - enable/disable plug events on a switch
  *