iwlwifi: pcie: retrieve and parse ACPI power limitations

Some platforms may have power limitations on PCIe cards connected to
specific root ports.

This information is encoded as part of the ACPI tables, for instance:
<snip>
           Name (SPLX, Package (0x02)
           {
               Zero,
               Package (0x03)
               {
                   0x07,
                   0x00000500,
                   0x80000000
               }
           })

           Method (SPLC, 0, Serialized)
           {
               Return (SPLX)
           }
</snip>

The structure returned contains the domain type, the default power
limitation and the default time window (reserved for future use).

Upon PCI probing, call the relevant ACPI method, parse the returned
structure, and save the power limitation.

Signed-off-by: Ido Yariv <idox.yariv@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-trans.h b/drivers/net/wireless/iwlwifi/iwl-trans.h
index 1f065cf..a350abe 100644
--- a/drivers/net/wireless/iwlwifi/iwl-trans.h
+++ b/drivers/net/wireless/iwlwifi/iwl-trans.h
@@ -523,6 +523,7 @@ enum iwl_trans_state {
  *	starting the firmware, used for tracing
  * @rx_mpdu_cmd_hdr_size: used for tracing, amount of data before the
  *	start of the 802.11 header in the @rx_mpdu_cmd
+ * @dflt_pwr_limit: default power limit fetched from the platform (ACPI)
  */
 struct iwl_trans {
 	const struct iwl_trans_ops *ops;
@@ -551,6 +552,8 @@ struct iwl_trans {
 	struct lockdep_map sync_cmd_lockdep_map;
 #endif
 
+	u64 dflt_pwr_limit;
+
 	/* pointer to trans specific struct */
 	/*Ensure that this pointer will always be aligned to sizeof pointer */
 	char trans_specific[0] __aligned(sizeof(void *));