Subject: [PATCH 11/19] e1000: Add 82540 specific hardware code.

From: Auke Kok <[email-masked]>
Date: Thu, 29 Mar 2007 09:40:19 -0700

From: Jeb Cramer <[email-masked]>

Adapter-specific code for the 82540.

Signed-off-by: Jeb Cramer <[email-masked]>
Signed-off-by: Auke Kok <[email-masked]>
---

 drivers/net/e1000/e1000_82540.c |  670 +++++++++++++++++++++++++++++++++++++++
 1 files changed, 670 insertions(+), 0 deletions(-)

diff --git a/drivers/net/e1000/e1000_82540.c b/drivers/net/e1000/e1000_82540.c
new file mode 100644
index 0000000..41549b8
--- /dev/null
+++ b/drivers/net/e1000/e1000_82540.c
@@ -0,0 +1,670 @@
+/*******************************************************************************
+
+  Intel PRO/1000 Linux driver
+  Copyright(c) 1999 - 2007 Intel Corporation.
+
+  This program is free software; you can redistribute it and/or modify it
+  under the terms and conditions of the GNU General Public License,
+  version 2, as published by the Free Software Foundation.
+
+  This program is distributed in the hope it will be useful, but WITHOUT
+  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+  more details.
+
+  You should have received a copy of the GNU General Public License along with
+  this program; if not, write to the Free Software Foundation, Inc.,
+  51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+
+  The full GNU General Public License is included in this distribution in
+  the file called "COPYING".
+
+  Contact Information:
+  Linux NICS <[email-masked]>
+  e1000-devel Mailing List <[email-masked]>
+  Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
+
+*******************************************************************************/
+
+/* e1000_82540
+ * e1000_82545
+ * e1000_82546
+ * e1000_82545_rev_3
+ * e1000_82546_rev_3
+ */
+
+#include "e1000_api.h"
+
+void e1000_init_function_pointers_82540(struct e1000_hw *hw);
+
+static s32  e1000_init_phy_params_82540(struct e1000_hw *hw);
+static s32  e1000_init_nvm_params_82540(struct e1000_hw *hw);
+static s32  e1000_init_mac_params_82540(struct e1000_hw *hw);
+static s32  e1000_adjust_serdes_amplitude_82540(struct e1000_hw *hw);
+static void e1000_clear_hw_cntrs_82540(struct e1000_hw *hw);
+static s32  e1000_init_hw_82540(struct e1000_hw *hw);
+static s32  e1000_reset_hw_82540(struct e1000_hw *hw);
+static s32  e1000_set_phy_mode_82540(struct e1000_hw *hw);
+static s32  e1000_set_vco_speed_82540(struct e1000_hw *hw);
+static s32  e1000_setup_copper_link_82540(struct e1000_hw *hw);
+static s32  e1000_setup_fiber_serdes_link_82540(struct e1000_hw *hw);
+
+/**
+ * e1000_init_phy_params_82540 - Init PHY func ptrs.
+ * @hw: pointer to the HW structure
+ *
+ * This is a function pointer entry point called by the api module.
+ **/
+static s32
+e1000_init_phy_params_82540(struct e1000_hw *hw)
+{
+	struct e1000_phy_info *phy = &hw->phy;
+	struct e1000_functions *func = &hw->func;
+	s32 ret_val = E1000_SUCCESS;
+
+	phy->addr                       = 1;
+	phy->autoneg_mask               = AUTONEG_ADVERTISE_SPEED_DEFAULT;
+	phy->reset_delay_us             = 10000;
+	phy->type                       = e1000_phy_m88;
+
+	/* Function Pointers */
+	func->check_polarity            = e1000_check_polarity_m88;
+	func->commit_phy                = e1000_phy_sw_reset_generic;
+	func->force_speed_duplex        = e1000_phy_force_speed_duplex_m88;
+	func->get_cable_length          = e1000_get_cable_length_m88;
+	func->get_cfg_done              = e1000_get_cfg_done_generic;
+	func->read_phy_reg              = e1000_read_phy_reg_m88;
+	func->reset_phy                 = e1000_phy_hw_reset_generic;
+	func->write_phy_reg             = e1000_write_phy_reg_m88;
+	func->get_phy_info              = e1000_get_phy_info_m88;
+
+	ret_val = e1000_get_phy_id(hw);
+	if (ret_val)
+		goto out;
+
+	/* Verify phy id */
+	switch (hw->mac.type) {
+	case e1000_82540:
+	case e1000_82545:
+	case e1000_82545_rev_3:
+	case e1000_82546:
+	case e1000_82546_rev_3:
+		if (phy->id == M88E1011_I_PHY_ID)
+			break;
+		/* Fall Through */
+	default:
+		ret_val = -E1000_ERR_PHY;
+		goto out;
+		break;
+	}
+
+out:
+	return ret_val;
+}
+
+/**
+ * e1000_init_nvm_params_82540 - Init NVM func ptrs.
+ * @hw: pointer to the HW structure
+ *
+ * This is a function pointer entry point called by the api module.
+ **/
+static s32
+e1000_init_nvm_params_82540(struct e1000_hw *hw)
+{
+	struct e1000_nvm_info *nvm = &hw->nvm;
+	struct e1000_functions *func = &hw->func;
+	u32 eecd = E1000_READ_REG(hw, E1000_EECD);
+
+	DEBUGFUNC("e1000_init_nvm_params_82540");
+
+	nvm->type               = e1000_nvm_eeprom_microwire;
+	nvm->delay_usec         = 50;
+	nvm->opcode_bits        = 3;
+	switch (nvm->override) {
+	case e1000_nvm_override_microwire_large:
+		nvm->address_bits       = 8;
+		nvm->word_size          = 256;
+		break;
+	case e1000_nvm_override_microwire_small:
+		nvm->address_bits       = 6;
+		nvm->word_size          = 64;
+		break;
+	default:
+		nvm->address_bits       = eecd & E1000_EECD_SIZE ? 8 : 6;
+		nvm->word_size          = eecd & E1000_EECD_SIZE ? 256 : 64;
+		break;
+	}
+
+	/* Function Pointers */
+	func->acquire_nvm        = e1000_acquire_nvm_generic;
+	func->read_nvm           = e1000_read_nvm_microwire;
+	func->release_nvm        = e1000_release_nvm_generic;
+	func->update_nvm         = e1000_update_nvm_checksum_generic;
+	func->valid_led_default  = e1000_valid_led_default_generic;
+	func->validate_nvm       = e1000_validate_nvm_checksum_generic;
+	func->write_nvm          = e1000_write_nvm_microwire;
+
+	return E1000_SUCCESS;
+}
+
+/**
+ * e1000_init_mac_params_82540 - Init MAC func ptrs.
+ * @hw: pointer to the HW structure
+ *
+ * This is a function pointer entry point called by the api module.
+ **/
+static s32
+e1000_init_mac_params_82540(struct e1000_hw *hw)
+{
+	struct e1000_mac_info *mac = &hw->mac;
+	struct e1000_functions *func = &hw->func;
+	s32 ret_val = E1000_SUCCESS;
+
+	DEBUGFUNC("e1000_init_mac_params_82540");
+
+	/* Set media type */
+	switch (hw->device_id) {
+	case E1000_DEV_ID_82545EM_FIBER:
+	case E1000_DEV_ID_82545GM_FIBER:
+	case E1000_DEV_ID_82546EB_FIBER:
+	case E1000_DEV_ID_82546GB_FIBER:
+		hw->media_type = e1000_media_type_fiber;
+		break;
+	case E1000_DEV_ID_82545GM_SERDES:
+	case E1000_DEV_ID_82546GB_SERDES:
+		hw->media_type = e1000_media_type_internal_serdes;
+		break;
+	default:
+		hw->media_type = e1000_media_type_copper;
+		break;
+	}
+
+	/* Set mta register count */
+	mac->mta_reg_count = 128;
+	/* Set rar entry count */
+	mac->rar_entry_count = E1000_RAR_ENTRIES;
+
+	/* Function pointers */
+
+	/* bus type/speed/width */
+	func->get_bus_info = e1000_get_bus_info_pci_generic;
+	/* reset */
+	func->reset_hw = e1000_reset_hw_82540;
+	/* hw initialization */
+	func->init_hw = e1000_init_hw_82540;
+	/* link setup */
+	func->setup_link = e1000_setup_link_generic;
+	/* physical interface setup */
+	func->setup_physical_interface =
+	        (hw->media_type == e1000_media_type_copper)
+	                ? e1000_setup_copper_link_82540
+	                : e1000_setup_fiber_serdes_link_82540;
+	/* check for link */
+	switch (hw->media_type) {
+	case e1000_media_type_copper:
+		func->check_for_link = e1000_check_for_copper_link_generic;
+		break;
+	case e1000_media_type_fiber:
+		func->check_for_link = e1000_check_for_fiber_link_generic;
+		break;
+	case e1000_media_type_internal_serdes:
+		func->check_for_link = e1000_check_for_serdes_link_generic;
+		break;
+	default:
+		ret_val = -E1000_ERR_CONFIG;
+		goto out;
+		break;
+	}
+	/* link info */
+	func->get_link_up_info =
+	        (hw->media_type == e1000_media_type_copper)
+	                ? e1000_get_speed_and_duplex_copper_generic
+	                : e1000_get_speed_and_duplex_fiber_serdes_generic;
+	/* multicast address update */
+	func->mc_addr_list_update = e1000_mc_addr_list_update_generic;
+	/* writing VFTA */
+	func->write_vfta = e1000_write_vfta_generic;
+	/* clearing VFTA */
+	func->clear_vfta = e1000_clear_vfta_generic;
+	/* setting MTA */
+	func->mta_set = e1000_mta_set_generic;
+	/* setup LED */
+	func->setup_led = e1000_setup_led_generic;
+	/* cleanup LED */
+	func->cleanup_led = e1000_cleanup_led_generic;
+	/* turn on/off LED */
+	func->led_on = e1000_led_on_generic;
+	func->led_off = e1000_led_off_generic;
+	/* clear hardware counters */
+	func->clear_hw_cntrs = e1000_clear_hw_cntrs_82540;
+
+out:
+	return ret_val;
+}
+
+/**
+ * e1000_init_function_pointers_82540 - Init func ptrs.
+ * @hw: pointer to the HW structure
+ *
+ * The only function explicitly called by the api module to initialize
+ * all function pointers and parameters.
+ **/
+void
+e1000_init_function_pointers_82540(struct e1000_hw *hw)
+{
+	DEBUGFUNC("e1000_init_function_pointers_82540");
+
+	hw->func.init_mac_params = e1000_init_mac_params_82540;
+	hw->func.init_nvm_params = e1000_init_nvm_params_82540;
+	hw->func.init_phy_params = e1000_init_phy_params_82540;
+}
+
+/**
+ *  e1000_reset_hw_82540 - Reset hardware
+ *  @hw: pointer to the HW structure
+ *
+ *  This resets the hardware into a known state.  This is a
+ *  function pointer entry point called by the api module.
+ **/
+static s32
+e1000_reset_hw_82540(struct e1000_hw *hw)
+{
+	u32 ctrl, icr, manc;
+	s32 ret_val = E1000_SUCCESS;
+
+	DEBUGFUNC("e1000_reset_hw_82540");
+
+	DEBUGOUT("Masking off all interrupts\n");
+	E1000_WRITE_REG(hw, E1000_IMC, 0xFFFFFFFF);
+
+	E1000_WRITE_REG(hw, E1000_RCTL, 0);
+	E1000_WRITE_REG(hw, E1000_TCTL, E1000_TCTL_PSP);
+	E1000_WRITE_FLUSH(hw);
+
+	/* Delay to allow any outstanding PCI transactions to complete
+	 * before resetting the device.
+	 */
+	msleep(10);
+
+	ctrl = E1000_READ_REG(hw, E1000_CTRL);
+
+	DEBUGOUT("Issuing a global reset to 82540/82545/82546 MAC\n");
+	switch (hw->mac.type) {
+	case e1000_82545_rev_3:
+	case e1000_82546_rev_3:
+		E1000_WRITE_REG(hw, E1000_CTRL_DUP, ctrl | E1000_CTRL_RST);
+		break;
+	default:
+		/* These controllers can't ack the 64-bit write when
+		 * issuing the reset, so we use IO-mapping as a
+		 * workaround to issue the reset.
+		 */
+		E1000_WRITE_REG_IO(hw, E1000_CTRL, ctrl | E1000_CTRL_RST);
+		break;
+	}
+
+	/* Wait for EEPROM reload */
+	msleep(5);
+
+	/* Disable HW ARPs on ASF enabled adapters */
+	manc = E1000_READ_REG(hw, E1000_MANC);
+	manc &= ~E1000_MANC_ARP_EN;
+	E1000_WRITE_REG(hw, E1000_MANC, manc);
+
+	E1000_WRITE_REG(hw, E1000_IMC, 0xffffffff);
+	icr = E1000_READ_REG(hw, E1000_ICR);
+
+	return ret_val;
+}
+
+/**
+ *  e1000_init_hw_82540 - Initialize hardware
+ *  @hw: pointer to the HW structure
+ *
+ *  This inits the hardware readying it for operation.  This is a
+ *  function pointer entry point called by the api module.
+ **/
+static s32
+e1000_init_hw_82540(struct e1000_hw *hw)
+{
+	struct e1000_mac_info *mac = &hw->mac;
+	u32 txdctl, ctrl_ext;
+	s32 ret_val = E1000_SUCCESS;
+	u16 i;
+
+	DEBUGFUNC("e1000_init_hw_82540");
+
+	/* Initialize identification LED */
+	ret_val = e1000_id_led_init_generic(hw);
+	if (ret_val) {
+		DEBUGOUT("Error initializing identification LED\n");
+		goto out;
+	}
+
+	/* Disabling VLAN filtering */
+	DEBUGOUT("Initializing the IEEE VLAN\n");
+	if (mac->type < e1000_82545_rev_3) {
+		E1000_WRITE_REG(hw, E1000_VET, 0);
+	}
+	e1000_clear_vfta(hw);
+
+	/* Setup the receive address. */
+	e1000_init_rx_addrs_generic(hw, mac->rar_entry_count);
+
+	/* Zero out the Multicast HASH table */
+	DEBUGOUT("Zeroing the MTA\n");
+	for (i = 0; i < mac->mta_reg_count; i++) {
+		E1000_WRITE_REG_ARRAY(hw, E1000_MTA, i, 0);
+		/* Avoid back to back register writes by adding the register
+		 * read (flush).  This is to protect against some strange
+		 * bridge configurations that may issue Memory Write Block
+		 * (MWB) to our register space.  The *_rev_3 hardware at
+		 * least doesn't respond correctly to every other dword in an
+		 * MWB to our register space.
+		 */
+		E1000_WRITE_FLUSH(hw);
+	}
+
+	if (mac->type < e1000_82545_rev_3)
+		e1000_pcix_mmrbc_workaround_generic(hw);
+
+	/* Setup link and flow control */
+	ret_val = e1000_setup_link(hw);
+
+	txdctl = E1000_READ_REG(hw, E1000_TXDCTL);
+	txdctl = (txdctl & ~E1000_TXDCTL_WTHRESH) |
+	         E1000_TXDCTL_FULL_TX_DESC_WB;
+	E1000_WRITE_REG(hw, E1000_TXDCTL, txdctl);
+
+	/* Clear all of the statistics registers (clear on read).  It is
+	 * important that we do this after we have tried to establish link
+	 * because the symbol error count will increment wildly if there
+	 * is no link.
+	 */
+	e1000_clear_hw_cntrs_82540(hw);
+
+	if ((hw->device_id == E1000_DEV_ID_82546GB_QUAD_COPPER) ||
+	    (hw->device_id == E1000_DEV_ID_82546GB_QUAD_COPPER_KSP3)) {
+		ctrl_ext = E1000_READ_REG(hw, E1000_CTRL_EXT);
+		/* Relaxed ordering must be disabled to avoid a parity
+		 * error crash in a PCI slot. */
+		ctrl_ext |= E1000_CTRL_EXT_RO_DIS;
+		E1000_WRITE_REG(hw, E1000_CTRL_EXT, ctrl_ext);
+	}
+
+out:
+	return ret_val;
+}
+
+/**
+ *  e1000_setup_copper_link_82540 - Configure copper link settings
+ *  @hw: pointer to the HW structure
+ *
+ *  Calls the appropriate function to configure the link for auto-neg or forced
+ *  speed and duplex.  Then we check for link, once link is established calls
+ *  to configure collision distance and flow control are called.  If link is
+ *  not established, we return -E1000_ERR_PHY (-2).  This is a function
+ *  pointer entry point called by the api module.
+ **/
+static s32
+e1000_setup_copper_link_82540(struct e1000_hw *hw)
+{
+	u32 ctrl;
+	s32 ret_val = E1000_SUCCESS;
+	u16 data;
+
+	DEBUGFUNC("e1000_setup_copper_link_82540");
+
+	ctrl = E1000_READ_REG(hw, E1000_CTRL);
+	ctrl |= E1000_CTRL_SLU;
+	ctrl &= ~(E1000_CTRL_FRCSPD | E1000_CTRL_FRCDPX);
+	E1000_WRITE_REG(hw, E1000_CTRL, ctrl);
+
+	ret_val = e1000_set_phy_mode_82540(hw);
+	if (ret_val)
+		goto out;
+
+	if (hw->mac.type == e1000_82545_rev_3 ||
+	    hw->mac.type == e1000_82546_rev_3) {
+		ret_val = e1000_read_phy_reg(hw, M88E1000_PHY_SPEC_CTRL, &data);
+		if (ret_val)
+			goto out;
+		data |= 0x00000008;
+		ret_val = e1000_write_phy_reg(hw, M88E1000_PHY_SPEC_CTRL, data);
+		if (ret_val)
+			goto out;
+	}
+
+	ret_val = e1000_copper_link_setup_m88(hw);
+	if (ret_val)
+		goto out;
+
+	ret_val = e1000_setup_copper_link_generic(hw);
+
+out:
+	return ret_val;
+}
+
+/**
+ *  e1000_setup_fiber_serdes_link_82540 - Setup link for fiber/serdes
+ *  @hw: pointer to the HW structure
+ *
+ *  Set the output amplitude to the value in the EEPROM and adjust the VCO
+ *  speed to improve Bit Error Rate (BER) performance.  Configures collision
+ *  distance and flow control for fiber and serdes links.  Upon successful
+ *  setup, poll for link.  This is a function pointer entry point called by
+ *  the api module.
+ **/
+static s32
+e1000_setup_fiber_serdes_link_82540(struct e1000_hw *hw)
+{
+	struct e1000_mac_info *mac = &hw->mac;
+	s32 ret_val = E1000_SUCCESS;
+
+	DEBUGFUNC("e1000_setup_fiber_serdes_link_82540");
+
+	switch (mac->type) {
+	case e1000_82545_rev_3:
+	case e1000_82546_rev_3:
+		if (hw->media_type == e1000_media_type_internal_serdes) {
+			/* If we're on serdes media, adjust the output
+			 * amplitude to value set in the EEPROM.
+			 */
+			ret_val = e1000_adjust_serdes_amplitude_82540(hw);
+			if (ret_val)
+				goto out;
+		}
+		/* Adjust VCO speed to improve BER performance */
+		ret_val = e1000_set_vco_speed_82540(hw);
+		if (ret_val)
+			goto out;
+	default:
+		break;
+	}
+
+	ret_val = e1000_setup_fiber_serdes_link_generic(hw);
+
+out:
+	return ret_val;
+}
+
+/**
+ *  e1000_adjust_serdes_amplitude_82540 - Adjust amplitude based on EEPROM
+ *  @hw: pointer to the HW structure
+ *
+ *  Adjust the SERDES ouput amplitude based on the EEPROM settings.
+ **/
+static s32
+e1000_adjust_serdes_amplitude_82540(struct e1000_hw *hw)
+{
+	s32 ret_val = E1000_SUCCESS;
+	u16 nvm_data;
+
+	DEBUGFUNC("e1000_adjust_serdes_amplitude_82540");
+
+	ret_val = e1000_read_nvm(hw, NVM_SERDES_AMPLITUDE, 1, &nvm_data);
+	if (ret_val) {
+		goto out;
+	}
+
+	if (nvm_data != NVM_RESERVED_WORD) {
+		/* Adjust serdes output amplitude only. */
+		nvm_data &= NVM_SERDES_AMPLITUDE_MASK;
+		ret_val = e1000_write_phy_reg(hw,
+		                             M88E1000_PHY_EXT_CTRL,
+		                             nvm_data);
+		if (ret_val)
+			goto out;
+	}
+
+out:
+	return ret_val;
+}
+
+/**
+ *  e1000_set_vco_speed_82540 - Set VCO speed for better performance
+ *  @hw: pointer to the HW structure
+ *
+ *  Set the VCO speed to improve Bit Error Rate (BER) performance.
+ **/
+static s32
+e1000_set_vco_speed_82540(struct e1000_hw *hw)
+{
+	s32  ret_val = E1000_SUCCESS;
+	u16 default_page = 0;
+	u16 phy_data;
+
+	DEBUGFUNC("e1000_set_vco_speed_82540");
+
+	/* Set PHY register 30, page 5, bit 8 to 0 */
+
+	ret_val = e1000_read_phy_reg(hw,
+	                            M88E1000_PHY_PAGE_SELECT,
+	                            &default_page);
+	if (ret_val)
+		goto out;
+
+	ret_val = e1000_write_phy_reg(hw, M88E1000_PHY_PAGE_SELECT, 0x0005);
+	if (ret_val)
+		goto out;
+
+	ret_val = e1000_read_phy_reg(hw, M88E1000_PHY_GEN_CONTROL, &phy_data);
+	if (ret_val)
+		goto out;
+
+	phy_data &= ~M88E1000_PHY_VCO_REG_BIT8;
+	ret_val = e1000_write_phy_reg(hw, M88E1000_PHY_GEN_CONTROL, phy_data);
+	if (ret_val)
+		goto out;
+
+	/* Set PHY register 30, page 4, bit 11 to 1 */
+
+	ret_val = e1000_write_phy_reg(hw, M88E1000_PHY_PAGE_SELECT, 0x0004);
+	if (ret_val)
+		goto out;
+
+	ret_val = e1000_read_phy_reg(hw, M88E1000_PHY_GEN_CONTROL, &phy_data);
+	if (ret_val)
+		goto out;
+
+	phy_data |= M88E1000_PHY_VCO_REG_BIT11;
+	ret_val = e1000_write_phy_reg(hw, M88E1000_PHY_GEN_CONTROL, phy_data);
+	if (ret_val)
+		goto out;
+
+	ret_val = e1000_write_phy_reg(hw, M88E1000_PHY_PAGE_SELECT,
+	                              default_page);
+
+out:
+	return ret_val;
+}
+
+/**
+ *  e1000_set_phy_mode_82540 - Set PHY to class A mode
+ *  @hw: pointer to the HW structure
+ *
+ *  Sets the PHY to class A mode and assumes the following operations will
+ *  follow to enable the new class mode:
+ *    1.  Do a PHY soft reset.
+ *    2.  Restart auto-negotiation or force link.
+ **/
+static s32
+e1000_set_phy_mode_82540(struct e1000_hw *hw)
+{
+	struct e1000_phy_info *phy = &hw->phy;
+	s32 ret_val = E1000_SUCCESS;
+	u16 nvm_data;
+
+	DEBUGFUNC("e1000_set_phy_mode_82540");
+
+	if (hw->mac.type != e1000_82545_rev_3)
+		goto out;
+
+	ret_val = e1000_read_nvm(hw, NVM_PHY_CLASS_WORD, 1, &nvm_data);
+	if (ret_val) {
+		ret_val = -E1000_ERR_PHY;
+		goto out;
+	}
+
+	if ((nvm_data != NVM_RESERVED_WORD) && (nvm_data & NVM_PHY_CLASS_A)) {
+		ret_val = e1000_write_phy_reg(hw, M88E1000_PHY_PAGE_SELECT,
+					      0x000B);
+		if (ret_val) {
+			ret_val = -E1000_ERR_PHY;
+			goto out;
+		}
+		ret_val = e1000_write_phy_reg(hw,
+					     M88E1000_PHY_GEN_CONTROL,
+					     0x8104);
+		if (ret_val) {
+			ret_val = -E1000_ERR_PHY;
+			goto out;
+		}
+
+		phy->reset_disable = FALSE;
+	}
+
+out:
+	return ret_val;
+}
+
+/**
+ *  e1000_clear_hw_cntrs_82540 - Clear device specific hardware counters
+ *  @hw: pointer to the HW structure
+ *
+ *  Clears the hardware counters by reading the counter registers.
+ **/
+static void
+e1000_clear_hw_cntrs_82540(struct e1000_hw *hw)
+{
+	volatile u32 temp;
+
+	DEBUGFUNC("e1000_clear_hw_cntrs_82540");
+
+	e1000_clear_hw_cntrs_base_generic(hw);
+
+	temp = E1000_READ_REG(hw, E1000_PRC64);
+	temp = E1000_READ_REG(hw, E1000_PRC127);
+	temp = E1000_READ_REG(hw, E1000_PRC255);
+	temp = E1000_READ_REG(hw, E1000_PRC511);
+	temp = E1000_READ_REG(hw, E1000_PRC1023);
+	temp = E1000_READ_REG(hw, E1000_PRC1522);
+	temp = E1000_READ_REG(hw, E1000_PTC64);
+	temp = E1000_READ_REG(hw, E1000_PTC127);
+	temp = E1000_READ_REG(hw, E1000_PTC255);
+	temp = E1000_READ_REG(hw, E1000_PTC511);
+	temp = E1000_READ_REG(hw, E1000_PTC1023);
+	temp = E1000_READ_REG(hw, E1000_PTC1522);
+
+	temp = E1000_READ_REG(hw, E1000_ALGNERRC);
+	temp = E1000_READ_REG(hw, E1000_RXERRC);
+	temp = E1000_READ_REG(hw, E1000_TNCRS);
+	temp = E1000_READ_REG(hw, E1000_CEXTERR);
+	temp = E1000_READ_REG(hw, E1000_TSCTC);
+	temp = E1000_READ_REG(hw, E1000_TSCTFC);
+
+	temp = E1000_READ_REG(hw, E1000_MGTPRC);
+	temp = E1000_READ_REG(hw, E1000_MGTPDC);
+	temp = E1000_READ_REG(hw, E1000_MGTPTC);
+}
+