From 9a47cb988338796b70c544919a8b6ba1f2245edb Mon Sep 17 00:00:00 2001
From: Luca Coelho <luciano.coelho@intel.com>
Date: Sat, 19 Oct 2019 13:03:30 +0300
Subject: [PATCH] iwlwifi: pcie: add workaround for power gating in integrated 22000
Git-commit: 9a47cb988338796b70c544919a8b6ba1f2245edb
Patch-mainline: v5.4-rc6
References: jsc#SLE-13430

Add a workaround that forces power gating to be enabled on integrated
22000 devices.  This improves power saving in certain situations.

Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/wireless/intel/iwlwifi/iwl-csr.h       |  1 +
 drivers/net/wireless/intel/iwlwifi/iwl-prph.h      |  5 +++++
 .../net/wireless/intel/iwlwifi/pcie/trans-gen2.c   | 25 ++++++++++++++++++++++
 3 files changed, 31 insertions(+)

diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-csr.h b/drivers/net/wireless/intel/iwlwifi/iwl-csr.h
index cb4c5514a556..695bbaa86273 100644
--- a/drivers/net/wireless/intel/iwlwifi/iwl-csr.h
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-csr.h
@@ -279,6 +279,7 @@
  *         Indicates MAC is entering a power-saving sleep power-down.
  *         Not a good time to access device-internal resources.
  */
+#define CSR_GP_CNTRL_REG_FLAG_INIT_DONE		     (0x00000004)
 #define CSR_GP_CNTRL_REG_FLAG_GOING_TO_SLEEP         (0x00000010)
 #define CSR_GP_CNTRL_REG_FLAG_XTAL_ON		     (0x00000400)
 
diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-prph.h b/drivers/net/wireless/intel/iwlwifi/iwl-prph.h
index f47e0f97acf8..23c25a7665f2 100644
--- a/drivers/net/wireless/intel/iwlwifi/iwl-prph.h
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-prph.h
@@ -449,6 +449,11 @@ enum {
 #define PERSISTENCE_BIT			BIT(12)
 #define PREG_WFPM_ACCESS		BIT(12)
 
+#define HPM_HIPM_GEN_CFG			0xA03458
+#define HPM_HIPM_GEN_CFG_CR_PG_EN		BIT(0)
+#define HPM_HIPM_GEN_CFG_CR_SLP_EN		BIT(1)
+#define HPM_HIPM_GEN_CFG_CR_FORCE_ACTIVE	BIT(10)
+
 #define UREG_DOORBELL_TO_ISR6		0xA05C04
 #define UREG_DOORBELL_TO_ISR6_NMI_BIT	BIT(0)
 #define UREG_DOORBELL_TO_ISR6_SUSPEND	BIT(18)
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans-gen2.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans-gen2.c
index df8455f14e4d..ca3bb4d65b00 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/trans-gen2.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans-gen2.c
@@ -57,6 +57,24 @@
 #include "internal.h"
 #include "fw/dbg.h"
 
+static int iwl_pcie_gen2_force_power_gating(struct iwl_trans *trans)
+{
+	iwl_set_bits_prph(trans, HPM_HIPM_GEN_CFG,
+			  HPM_HIPM_GEN_CFG_CR_FORCE_ACTIVE);
+	udelay(20);
+	iwl_set_bits_prph(trans, HPM_HIPM_GEN_CFG,
+			  HPM_HIPM_GEN_CFG_CR_PG_EN |
+			  HPM_HIPM_GEN_CFG_CR_SLP_EN);
+	udelay(20);
+	iwl_clear_bits_prph(trans, HPM_HIPM_GEN_CFG,
+			    HPM_HIPM_GEN_CFG_CR_FORCE_ACTIVE);
+
+	iwl_trans_sw_reset(trans);
+	iwl_clear_bit(trans, CSR_GP_CNTRL, CSR_GP_CNTRL_REG_FLAG_INIT_DONE);
+
+	return 0;
+}
+
 /*
  * Start up NIC's basic functionality after it has been reset
  * (e.g. after platform boot, or shutdown via iwl_pcie_apm_stop())
@@ -92,6 +110,13 @@ int iwl_pcie_gen2_apm_init(struct iwl_trans *trans)
 
 	iwl_pcie_apm_config(trans);
 
+	if (trans->trans_cfg->device_family == IWL_DEVICE_FAMILY_22000 &&
+	    trans->cfg->integrated) {
+		ret = iwl_pcie_gen2_force_power_gating(trans);
+		if (ret)
+			return ret;
+	}
+
 	ret = iwl_finish_nic_init(trans, trans->trans_cfg);
 	if (ret)
 		return ret;
-- 
2.16.4