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Subject[PATCH v2 07/28] thunderbolt: Set sleep bit when suspending switch
Date
Thunderbolt 2 devices and beyond link controller needs to be notified
when a switch is going to be suspended by setting bit 31 in LC_SX_CTRL
register. Add this functionality to the software connection manager.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
drivers/thunderbolt/lc.c | 44 +++++++++++++++++++++++++++++++++++
drivers/thunderbolt/switch.c | 6 ++---
drivers/thunderbolt/tb.h | 1 +
drivers/thunderbolt/tb_regs.h | 2 ++
4 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/drivers/thunderbolt/lc.c b/drivers/thunderbolt/lc.c
index a5dddf176546..ae1e92611c3e 100644
--- a/drivers/thunderbolt/lc.c
+++ b/drivers/thunderbolt/lc.c
@@ -133,3 +133,47 @@ void tb_lc_unconfigure_link(struct tb_switch *sw)
tb_lc_configure_lane(up, false);
tb_lc_configure_lane(down, false);
}
+
+/**
+ * tb_lc_set_sleep() - Inform LC that the switch is going to sleep
+ * @sw: Switch to set sleep
+ *
+ * Let the switch link controllers know that the switch is going to
+ * sleep.
+ */
+int tb_lc_set_sleep(struct tb_switch *sw)
+{
+ int start, size, nlc, ret, i;
+ u32 desc;
+
+ if (sw->generation < 2)
+ return 0;
+
+ ret = read_lc_desc(sw, &desc);
+ if (ret)
+ return ret;
+
+ /* Figure out number of link controllers */
+ nlc = desc & TB_LC_DESC_NLC_MASK;
+ 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;
+
+ /* For each link controller set sleep bit */
+ for (i = 0; i < nlc; i++) {
+ unsigned int offset = sw->cap_lc + start + i * size;
+ u32 ctrl;
+
+ ret = tb_sw_read(sw, &ctrl, TB_CFG_SWITCH,
+ offset + TB_LC_SX_CTRL, 1);
+ if (ret)
+ return ret;
+
+ ctrl |= TB_LC_SX_CTRL_SLP;
+ ret = tb_sw_write(sw, &ctrl, TB_CFG_SWITCH,
+ offset + TB_LC_SX_CTRL, 1);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index 760332f57b5c..1eee2502b5ba 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -1604,10 +1604,8 @@ void tb_switch_suspend(struct tb_switch *sw)
if (!tb_is_upstream_port(&sw->ports[i]) && sw->ports[i].remote)
tb_switch_suspend(sw->ports[i].remote->sw);
}
- /*
- * TODO: invoke tb_cfg_prepare_to_sleep here? does not seem to have any
- * effect?
- */
+
+ tb_lc_set_sleep(sw);
}

struct tb_sw_lookup {
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index e61c2409021d..3160169389cc 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -453,6 +453,7 @@ 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);
+int tb_lc_set_sleep(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 e0f867dad5cf..1ab6e0fb31c0 100644
--- a/drivers/thunderbolt/tb_regs.h
+++ b/drivers/thunderbolt/tb_regs.h
@@ -239,6 +239,7 @@ struct tb_regs_hop {

/* Common link controller registers */
#define TB_LC_DESC 0x02
+#define TB_LC_DESC_NLC_MASK GENMASK(3, 0)
#define TB_LC_DESC_SIZE_SHIFT 8
#define TB_LC_DESC_SIZE_MASK GENMASK(15, 8)
#define TB_LC_DESC_PORT_SIZE_SHIFT 16
@@ -250,5 +251,6 @@ struct tb_regs_hop {
#define TB_LC_SX_CTRL_L1C BIT(16)
#define TB_LC_SX_CTRL_L2C BIT(20)
#define TB_LC_SX_CTRL_UPSTREAM BIT(30)
+#define TB_LC_SX_CTRL_SLP BIT(31)

#endif
--
2.20.1
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