thunderbolt: Configure lanes when switch is initialized

Thunderbolt 2 devices and beyond need to have additional bits set in
link controller specific registers. This includes two bits in LC_SX_CTRL
that tell the link controller which lane is connected and whether it is
upstream facing or not.

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

diff --git a/drivers/thunderbolt/lc.c b/drivers/thunderbolt/lc.c
index 2134a55ed8372df49c76f10029163ea379dccad1..a5dddf1765464e408eb362ff192086e3d8eaf2c7 100644 (file)
--- a/drivers/thunderbolt/lc.c
+++ b/drivers/thunderbolt/lc.c
@@ -19,3 +19,117 @@ int tb_lc_read_uuid(struct tb_switch *sw, u32 *uuid)
                return -EINVAL;
        return tb_sw_read(sw, uuid, TB_CFG_SWITCH, sw->cap_lc + TB_LC_FUSE, 4);
 }
+
+static int read_lc_desc(struct tb_switch *sw, u32 *desc)
+{
+       if (!sw->cap_lc)
+               return -EINVAL;
+       return tb_sw_read(sw, desc, TB_CFG_SWITCH, sw->cap_lc + TB_LC_DESC, 1);
+}
+
+static int find_port_lc_cap(struct tb_port *port)
+{
+       struct tb_switch *sw = port->sw;
+       int start, phys, ret, size;
+       u32 desc;
+
+       ret = read_lc_desc(sw, &desc);
+       if (ret)
+               return ret;
+
+       /* Start of port LC registers */
+       start = (desc & TB_LC_DESC_SIZE_MASK) >> TB_LC_DESC_SIZE_SHIFT;
+       size = (desc & TB_LC_DESC_PORT_SIZE_MASK) >> TB_LC_DESC_PORT_SIZE_SHIFT;
+       phys = tb_phy_port_from_link(port->port);
+
+       return sw->cap_lc + start + phys * size;
+}
+
+static int tb_lc_configure_lane(struct tb_port *port, bool configure)
+{
+       bool upstream = tb_is_upstream_port(port);
+       struct tb_switch *sw = port->sw;
+       u32 ctrl, lane;
+       int cap, ret;
+
+       if (sw->generation < 2)
+               return 0;
+
+       cap = find_port_lc_cap(port);
+       if (cap < 0)
+               return cap;
+
+       ret = tb_sw_read(sw, &ctrl, TB_CFG_SWITCH, cap + TB_LC_SX_CTRL, 1);
+       if (ret)
+               return ret;
+
+       /* Resolve correct lane */
+       if (port->port % 2)
+               lane = TB_LC_SX_CTRL_L1C;
+       else
+               lane = TB_LC_SX_CTRL_L2C;
+
+       if (configure) {
+               ctrl |= lane;
+               if (upstream)
+                       ctrl |= TB_LC_SX_CTRL_UPSTREAM;
+       } else {
+               ctrl &= ~lane;
+               if (upstream)
+                       ctrl &= ~TB_LC_SX_CTRL_UPSTREAM;
+       }
+
+       return tb_sw_write(sw, &ctrl, TB_CFG_SWITCH, cap + TB_LC_SX_CTRL, 1);
+}
+
+/**
+ * tb_lc_configure_link() - Let LC know about configured link
+ * @sw: Switch that is being added
+ *
+ * Informs LC of both parent switch and @sw that there is established
+ * link between the two.
+ */
+int tb_lc_configure_link(struct tb_switch *sw)
+{
+       struct tb_port *up, *down;
+       int ret;
+
+       if (!sw->config.enabled || !tb_route(sw))
+               return 0;
+
+       up = tb_upstream_port(sw);
+       down = tb_port_at(tb_route(sw), tb_to_switch(sw->dev.parent));
+
+       /* Configure parent link toward this switch */
+       ret = tb_lc_configure_lane(down, true);
+       if (ret)
+               return ret;
+
+       /* Configure upstream link from this switch to the parent */
+       ret = tb_lc_configure_lane(up, true);
+       if (ret)
+               tb_lc_configure_lane(down, false);
+
+       return ret;
+}
+
+/**
+ * tb_lc_unconfigure_link() - Let LC know about unconfigured link
+ * @sw: Switch to unconfigure
+ *
+ * Informs LC of both parent switch and @sw that the link between the
+ * two does not exist anymore.
+ */
+void tb_lc_unconfigure_link(struct tb_switch *sw)
+{
+       struct tb_port *up, *down;
+
+       if (sw->is_unplugged || !sw->config.enabled || !tb_route(sw))
+               return;
+
+       up = tb_upstream_port(sw);
+       down = tb_port_at(tb_route(sw), tb_to_switch(sw->dev.parent));
+
+       tb_lc_configure_lane(up, false);
+       tb_lc_configure_lane(down, false);
+}

diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index 63ff4c753d8987a171c2b006fe9dbe24efe84ebb..dd218dc4781b3f539d56255edb0debda808741e1 100644 (file)
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -1276,6 +1276,10 @@ int tb_switch_configure(struct tb_switch *sw)
        if (ret)
                return ret;
 
+       ret = tb_lc_configure_link(sw);
+       if (ret)
+               return ret;
+
        return tb_plug_events_active(sw, true);
 }
 
@@ -1486,6 +1490,7 @@ void tb_switch_remove(struct tb_switch *sw)
 
        if (!sw->is_unplugged)
                tb_plug_events_active(sw, false);
+       tb_lc_unconfigure_link(sw);
 
        tb_switch_nvm_remove(sw);
 
@@ -1545,6 +1550,10 @@ int tb_switch_resume(struct tb_switch *sw)
        if (err)
                return err;
 
+       err = tb_lc_configure_link(sw);
+       if (err)
+               return err;
+
        err = tb_plug_events_active(sw, true);
        if (err)
                return err;

diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index e52d39b25266a53bfcdef715b3c5061664408cfa..69e0534224d870ae7ca6bb2c014f0cc48fe60841 100644 (file)
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -465,6 +465,8 @@ int tb_drom_read(struct tb_switch *sw);
 int tb_drom_read_uid_only(struct tb_switch *sw, u64 *uid);
 
 int tb_lc_read_uuid(struct tb_switch *sw, u32 *uuid);
+int tb_lc_configure_link(struct tb_switch *sw);
+void tb_lc_unconfigure_link(struct tb_switch *sw);
 
 static inline int tb_route_length(u64 route)
 {

diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h
index 4895ae9f0b4016cccb9aab9c909869570794357f..e0f867dad5cf1ea7e0c92303bd94d6c4eacf9bd7 100644 (file)
--- a/drivers/thunderbolt/tb_regs.h
+++ b/drivers/thunderbolt/tb_regs.h
@@ -238,6 +238,17 @@ struct tb_regs_hop {
 } __packed;
 
 /* Common link controller registers */
+#define TB_LC_DESC                     0x02
+#define TB_LC_DESC_SIZE_SHIFT          8
+#define TB_LC_DESC_SIZE_MASK           GENMASK(15, 8)
+#define TB_LC_DESC_PORT_SIZE_SHIFT     16
+#define TB_LC_DESC_PORT_SIZE_MASK      GENMASK(27, 16)
 #define TB_LC_FUSE                     0x03
 
+/* Link controller registers */
+#define TB_LC_SX_CTRL                  0x96
+#define TB_LC_SX_CTRL_L1C              BIT(16)
+#define TB_LC_SX_CTRL_L2C              BIT(20)
+#define TB_LC_SX_CTRL_UPSTREAM         BIT(30)
+
 #endif