iwlwifi: consolidate apm_init() functions

Consolidate most iwlXXXX_apm_init() functions into single iwl_apm_init().
Keep iwl3945_apm_init(), but leverage iwl_apm_init() for most functionality.
Update 4965 init sequence to follow most recent factory recommendations.

Add following members to struct iwl_cfg to guide the init sequence:
pll_cfg_val (replaces needs_pll_cfg), set_l0s, use_bsm

Move L0S enable/disable from nic_config() functions to iwl_apm_init().
This satisifies the "FIXME: put here L1A -L0S w/a" notice, and complies
with factory-recommended sequence.

Add debug info message in iwl_apm_init(), and symmetrical message
in iwl_apm_stop().

Signed-off-by: Ben Cahill <ben.m.cahill@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 114 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-core.c b/drivers/net/wireless/iwlwifi/iwl-core.c
index 7ce8663fdb7b..1d7248cd1969 100644
--- a/drivers/net/wireless/iwlwifi/iwl-core.c
+++ b/drivers/net/wireless/iwlwifi/iwl-core.c
@@ -1369,6 +1369,8 @@ void iwl_apm_stop(struct iwl_priv *priv)
 {
 	unsigned long flags;
 
+	IWL_DEBUG_INFO(priv, "Stop card, put in low power state\n");
+
 	iwl_apm_stop_master(priv);
 
 	spin_lock_irqsave(&priv->lock, flags);
@@ -1382,6 +1384,118 @@ void iwl_apm_stop(struct iwl_priv *priv)
 }
 EXPORT_SYMBOL(iwl_apm_stop);
 
+
+/*
+ * Start up NIC's basic functionality after it has been reset
+ * (e.g. after platform boot, or shutdown via iwl_apm_stop())
+ * NOTE:  This does not load uCode nor start the embedded processor
+ */
+int iwl_apm_init(struct iwl_priv *priv)
+{
+	int ret = 0;
+	u16 lctl;
+
+	IWL_DEBUG_INFO(priv, "Init card's basic functions\n");
+
+	/*
+	 * Use "set_bit" below rather than "write", to preserve any hardware
+	 * bits already set by default after reset.
+	 */
+
+	/* Disable L0S exit timer (platform NMI Work/Around) */
+	iwl_set_bit(priv, CSR_GIO_CHICKEN_BITS,
+			  CSR_GIO_CHICKEN_BITS_REG_BIT_DIS_L0S_EXIT_TIMER);
+
+	/*
+	 * Disable L0s without affecting L1;
+	 *  don't wait for ICH L0s (ICH bug W/A)
+	 */
+	iwl_set_bit(priv, CSR_GIO_CHICKEN_BITS,
+			  CSR_GIO_CHICKEN_BITS_REG_BIT_L1A_NO_L0S_RX);
+
+	/* Set FH wait threshold to maximum (HW error during stress W/A) */
+	iwl_set_bit(priv, CSR_DBG_HPET_MEM_REG, CSR_DBG_HPET_MEM_REG_VAL);
+
+	/*
+	 * Enable HAP INTA (interrupt from management bus) to
+	 * wake device's PCI Express link L1a -> L0s
+	 * NOTE:  This is no-op for 3945 (non-existant bit)
+	 */
+	iwl_set_bit(priv, CSR_HW_IF_CONFIG_REG,
+				    CSR_HW_IF_CONFIG_REG_BIT_HAP_WAKE_L1A);
+
+	/*
+	 * HW bug W/A - costs negligible power consumption ...
+	 * Check if BIOS (or OS) enabled L1-ASPM on this device
+	 */
+	if (priv->cfg->set_l0s) {
+		lctl = iwl_pcie_link_ctl(priv);
+		if ((lctl & PCI_CFG_LINK_CTRL_VAL_L1_EN) ==
+					PCI_CFG_LINK_CTRL_VAL_L1_EN) {
+			/* L1-ASPM enabled; disable(!) L0S  */
+			iwl_set_bit(priv, CSR_GIO_REG,
+					CSR_GIO_REG_VAL_L0S_ENABLED);
+			IWL_DEBUG_POWER(priv, "L1 Enabled; Disabling L0S\n");
+		} else {
+			/* L1-ASPM disabled; enable(!) L0S */
+			iwl_clear_bit(priv, CSR_GIO_REG,
+					CSR_GIO_REG_VAL_L0S_ENABLED);
+			IWL_DEBUG_POWER(priv, "L1 Disabled; Enabling L0S\n");
+		}
+	}
+
+	/* Configure analog phase-lock-loop before activating to D0A */
+	if (priv->cfg->pll_cfg_val)
+		iwl_set_bit(priv, CSR_ANA_PLL_CFG, priv->cfg->pll_cfg_val);
+
+	/*
+	 * Set "initialization complete" bit to move adapter from
+	 * D0U* --> D0A* (powered-up active) state.
+	 */
+	iwl_set_bit(priv, CSR_GP_CNTRL, CSR_GP_CNTRL_REG_FLAG_INIT_DONE);
+
+	/*
+	 * Wait for clock stabilization; once stabilized, access to
+	 * device-internal resources is supported, e.g. iwl_write_prph()
+	 * and accesses to uCode SRAM.
+	 */
+	ret = iwl_poll_bit(priv, CSR_GP_CNTRL,
+			CSR_GP_CNTRL_REG_FLAG_MAC_CLOCK_READY,
+			CSR_GP_CNTRL_REG_FLAG_MAC_CLOCK_READY, 25000);
+	if (ret < 0) {
+		IWL_DEBUG_INFO(priv, "Failed to init the card\n");
+		goto out;
+	}
+
+	/*
+	 * Enable DMA and BSM (if used) clocks, wait for them to stabilize.
+	 * BSM (Boostrap State Machine) is only in 3945 and 4965;
+	 * later devices (i.e. 5000 and later) have non-volatile SRAM,
+	 * and don't need BSM to restore data after power-saving sleep.
+	 *
+	 * Write to "CLK_EN_REG"; "1" bits enable clocks, while "0" bits
+	 * do not disable clocks.  This preserves any hardware bits already
+	 * set by default in "CLK_CTRL_REG" after reset.
+	 */
+	if (priv->cfg->use_bsm)
+		iwl_write_prph(priv, APMG_CLK_EN_REG,
+			APMG_CLK_VAL_DMA_CLK_RQT | APMG_CLK_VAL_BSM_CLK_RQT);
+	else
+		iwl_write_prph(priv, APMG_CLK_EN_REG,
+			APMG_CLK_VAL_DMA_CLK_RQT);
+	udelay(20);
+
+	/* Disable L1-Active */
+	iwl_set_bits_prph(priv, APMG_PCIDEV_STT_REG,
+			  APMG_PCIDEV_STT_VAL_L1_ACT_DIS);
+
+out:
+	return ret;
+}
+EXPORT_SYMBOL(iwl_apm_init);
+
+
+
 void iwl_configure_filter(struct ieee80211_hw *hw,
 			  unsigned int changed_flags,
 			  unsigned int *total_flags,