thunderbolt: Enable plug events

Thunderbolt switches have a plug events capability. This patch adds the
tb_plug_events_active method and uses it to activate plug events during
switch allocation.

Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 53 insertions, 0 deletions

diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index e89121ffe44e..6d193a230cf4 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -99,6 +99,45 @@ static void tb_dump_switch(struct tb *tb, struct tb_regs_switch_header *sw)
 }
 
 /**
+ * tb_plug_events_active() - enable/disable plug events on a switch
+ *
+ * Also configures a sane plug_events_delay of 255ms.
+ *
+ * Return: Returns 0 on success or an error code on failure.
+ */
+static int tb_plug_events_active(struct tb_switch *sw, bool active)
+{
+        u32 data;
+        int res;
+
+        sw->config.plug_events_delay = 0xff;
+        res = tb_sw_write(sw, ((u32 *) &sw->config) + 4, TB_CFG_SWITCH, 4, 1);
+        if (res)
+                return res;
+
+        res = tb_sw_read(sw, &data, TB_CFG_SWITCH, sw->cap_plug_events + 1, 1);
+        if (res)
+                return res;
+
+        if (active) {
+                data = data & 0xFFFFFF83;
+                switch (sw->config.device_id) {
+                case 0x1513:
+                case 0x151a:
+                case 0x1549:
+                        break;
+                default:
+                        data |= 4;
+                }
+        } else {
+                data = data | 0x7c;
+        }
+        return tb_sw_write(sw, &data, TB_CFG_SWITCH,
+                           sw->cap_plug_events + 1, 1);
+}
+
+
+/**
  * tb_switch_free() - free a tb_switch and all downstream switches
  */
 void tb_switch_free(struct tb_switch *sw)
@@ -113,6 +152,8 @@ void tb_switch_free(struct tb_switch *sw)
                 sw->ports[i].remote = NULL;
         }
 
+        tb_plug_events_active(sw, false);
+
         kfree(sw->ports);
         kfree(sw);
 }
@@ -125,6 +166,7 @@ void tb_switch_free(struct tb_switch *sw)
 struct tb_switch *tb_switch_alloc(struct tb *tb, u64 route)
 {
         int i;
+        int cap;
         struct tb_switch *sw;
         int upstream_port = tb_cfg_get_upstream_port(tb->ctl, route);
         if (upstream_port < 0)
@@ -177,6 +219,16 @@ struct tb_switch *tb_switch_alloc(struct tb *tb, u64 route)
 
         /* TODO: I2C, IECS, EEPROM, link controller */
 
+        cap = tb_find_cap(&sw->ports[0], TB_CFG_SWITCH, TB_CAP_PLUG_EVENTS);
+        if (cap < 0) {
+                tb_sw_warn(sw, "cannot find TB_CAP_PLUG_EVENTS aborting\n");
+                goto err;
+        }
+        sw->cap_plug_events = cap;
+
+        if (tb_plug_events_active(sw, true))
+                goto err;
+
         return sw;
 err:
         kfree(sw->ports);
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 38e4c23c10fd..af123c4045e3 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -19,6 +19,7 @@ struct tb_switch {
         struct tb_regs_switch_header config;
         struct tb_port *ports;
         struct tb *tb;
+        int cap_plug_events; /* offset, zero if not found */
 };
 
 /**