thunderbolt: Add support for runtime PM

When Thunderbolt host controller is set to RTD3 mode (Runtime D3) it is
present all the time. Because of this it is important to runtime suspend
the controller whenever possible. In case of ICM we have following rules
which all needs to be true before the host controller can be put to D3:

  - The controller firmware reports to support RTD3
  - All the connected devices announce support for RTD3
  - There is no active XDomain connection

Implement this using standard Linux runtime PM APIs so that when all the
children devices are runtime suspended, the Thunderbolt host controller
PCI device is runtime suspended as well. The ICM firmware then starts
powering down power domains towards RTD3 but it can prevent this if it
detects that there is an active Display Port stream (this is not visible
to the software, though).

The Thunderbolt host controller will be runtime resumed either when
there is a remote wake event (device is connected or disconnected), or
when there is access from userspace that requires hardware access.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 9d9f0ca16bfb..5067d69d0501 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -67,6 +67,7 @@ struct tb_switch_nvm {
  * @no_nvm_upgrade: Prevent NVM upgrade of this switch
  * @safe_mode: The switch is in safe-mode
  * @boot: Whether the switch was already authorized on boot or not
+ * @rpm: The switch supports runtime PM
  * @authorized: Whether the switch is authorized by user or policy
  * @work: Work used to automatically authorize a switch
  * @security_level: Switch supported security level
@@ -101,6 +102,7 @@ struct tb_switch {
 	bool no_nvm_upgrade;
 	bool safe_mode;
 	bool boot;
+	bool rpm;
 	unsigned int authorized;
 	struct work_struct work;
 	enum tb_security_level security_level;
@@ -199,6 +201,8 @@ struct tb_path {
  * @resume_noirq: Connection manager specific resume_noirq
  * @suspend: Connection manager specific suspend
  * @complete: Connection manager specific complete
+ * @runtime_suspend: Connection manager specific runtime_suspend
+ * @runtime_resume: Connection manager specific runtime_resume
  * @handle_event: Handle thunderbolt event
  * @get_boot_acl: Get boot ACL list
  * @set_boot_acl: Set boot ACL list
@@ -217,6 +221,8 @@ struct tb_cm_ops {
 	int (*resume_noirq)(struct tb *tb);
 	int (*suspend)(struct tb *tb);
 	void (*complete)(struct tb *tb);
+	int (*runtime_suspend)(struct tb *tb);
+	int (*runtime_resume)(struct tb *tb);
 	void (*handle_event)(struct tb *tb, enum tb_cfg_pkg_type,
 			     const void *buf, size_t size);
 	int (*get_boot_acl)(struct tb *tb, uuid_t *uuids, size_t nuuids);
@@ -235,6 +241,8 @@ static inline void *tb_priv(struct tb *tb)
 	return (void *)tb->privdata;
 }
 
+#define TB_AUTOSUSPEND_DELAY		15000 /* ms */
+
 /* helper functions & macros */
 
 /**
@@ -364,6 +372,8 @@ int tb_domain_suspend_noirq(struct tb *tb);
 int tb_domain_resume_noirq(struct tb *tb);
 int tb_domain_suspend(struct tb *tb);
 void tb_domain_complete(struct tb *tb);
+int tb_domain_runtime_suspend(struct tb *tb);
+int tb_domain_runtime_resume(struct tb *tb);
 int tb_domain_approve_switch(struct tb *tb, struct tb_switch *sw);
 int tb_domain_approve_switch_key(struct tb *tb, struct tb_switch *sw);
 int tb_domain_challenge_switch_key(struct tb *tb, struct tb_switch *sw);