ixgbe_common.c

/*******************************************************************************

  Intel 10 Gigabit PCI Express Linux driver
  Copyright(c) 1999 - 2010 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:
  e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
  Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497

*******************************************************************************/

#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/list.h>
#include <linux/netdevice.h>

#include "ixgbe.h"
#include "ixgbe_common.h"
#include "ixgbe_phy.h"

static s32 ixgbe_poll_eeprom_eerd_done(struct ixgbe_hw *hw);
static s32 ixgbe_acquire_eeprom(struct ixgbe_hw *hw);
static s32 ixgbe_get_eeprom_semaphore(struct ixgbe_hw *hw);
static void ixgbe_release_eeprom_semaphore(struct ixgbe_hw *hw);
static s32 ixgbe_ready_eeprom(struct ixgbe_hw *hw);
static void ixgbe_standby_eeprom(struct ixgbe_hw *hw);
static void ixgbe_shift_out_eeprom_bits(struct ixgbe_hw *hw, u16 data,
                                        u16 count);
static u16 ixgbe_shift_in_eeprom_bits(struct ixgbe_hw *hw, u16 count);
static void ixgbe_raise_eeprom_clk(struct ixgbe_hw *hw, u32 *eec);
static void ixgbe_lower_eeprom_clk(struct ixgbe_hw *hw, u32 *eec);
static void ixgbe_release_eeprom(struct ixgbe_hw *hw);
static u16 ixgbe_calc_eeprom_checksum(struct ixgbe_hw *hw);

static void ixgbe_enable_rar(struct ixgbe_hw *hw, u32 index);
static void ixgbe_disable_rar(struct ixgbe_hw *hw, u32 index);
static s32 ixgbe_mta_vector(struct ixgbe_hw *hw, u8 *mc_addr);
static void ixgbe_add_uc_addr(struct ixgbe_hw *hw, u8 *addr, u32 vmdq);
static s32 ixgbe_setup_fc(struct ixgbe_hw *hw, s32 packetbuf_num);

/**
 *  ixgbe_start_hw_generic - Prepare hardware for Tx/Rx
 *  @hw: pointer to hardware structure
 *
 *  Starts the hardware by filling the bus info structure and media type, clears
 *  all on chip counters, initializes receive address registers, multicast
 *  table, VLAN filter table, calls routine to set up link and flow control
 *  settings, and leaves transmit and receive units disabled and uninitialized
 **/
s32 ixgbe_start_hw_generic(struct ixgbe_hw *hw)
{
	u32 ctrl_ext;

	/* Set the media type */
	hw->phy.media_type = hw->mac.ops.get_media_type(hw);

	/* Identify the PHY */
	hw->phy.ops.identify(hw);

	/* Clear the VLAN filter table */
	hw->mac.ops.clear_vfta(hw);

	/* Clear statistics registers */
	hw->mac.ops.clear_hw_cntrs(hw);

	/* Set No Snoop Disable */
	ctrl_ext = IXGBE_READ_REG(hw, IXGBE_CTRL_EXT);
	ctrl_ext |= IXGBE_CTRL_EXT_NS_DIS;
	IXGBE_WRITE_REG(hw, IXGBE_CTRL_EXT, ctrl_ext);
	IXGBE_WRITE_FLUSH(hw);

	/* Setup flow control */
	ixgbe_setup_fc(hw, 0);

	/* Clear adapter stopped flag */
	hw->adapter_stopped = false;

	return 0;
}

/**
 *  ixgbe_init_hw_generic - Generic hardware initialization
 *  @hw: pointer to hardware structure
 *
 *  Initialize the hardware by resetting the hardware, filling the bus info
 *  structure and media type, clears all on chip counters, initializes receive
 *  address registers, multicast table, VLAN filter table, calls routine to set
 *  up link and flow control settings, and leaves transmit and receive units
 *  disabled and uninitialized
 **/
s32 ixgbe_init_hw_generic(struct ixgbe_hw *hw)
{
	s32 status;

	/* Reset the hardware */
	status = hw->mac.ops.reset_hw(hw);

	if (status == 0) {
		/* Start the HW */
		status = hw->mac.ops.start_hw(hw);
	}

	return status;
}

/**
 *  ixgbe_clear_hw_cntrs_generic - Generic clear hardware counters
 *  @hw: pointer to hardware structure
 *
 *  Clears all hardware statistics counters by reading them from the hardware
 *  Statistics counters are clear on read.
 **/
s32 ixgbe_clear_hw_cntrs_generic(struct ixgbe_hw *hw)
{
	u16 i = 0;

	IXGBE_READ_REG(hw, IXGBE_CRCERRS);
	IXGBE_READ_REG(hw, IXGBE_ILLERRC);
	IXGBE_READ_REG(hw, IXGBE_ERRBC);
	IXGBE_READ_REG(hw, IXGBE_MSPDC);
	for (i = 0; i < 8; i++)
		IXGBE_READ_REG(hw, IXGBE_MPC(i));

	IXGBE_READ_REG(hw, IXGBE_MLFC);
	IXGBE_READ_REG(hw, IXGBE_MRFC);
	IXGBE_READ_REG(hw, IXGBE_RLEC);
	IXGBE_READ_REG(hw, IXGBE_LXONTXC);
	IXGBE_READ_REG(hw, IXGBE_LXONRXC);
	IXGBE_READ_REG(hw, IXGBE_LXOFFTXC);
	IXGBE_READ_REG(hw, IXGBE_LXOFFRXC);

	for (i = 0; i < 8; i++) {
		IXGBE_READ_REG(hw, IXGBE_PXONTXC(i));
		IXGBE_READ_REG(hw, IXGBE_PXONRXC(i));
		IXGBE_READ_REG(hw, IXGBE_PXOFFTXC(i));
		IXGBE_READ_REG(hw, IXGBE_PXOFFRXC(i));
	}

	IXGBE_READ_REG(hw, IXGBE_PRC64);
	IXGBE_READ_REG(hw, IXGBE_PRC127);
	IXGBE_READ_REG(hw, IXGBE_PRC255);
	IXGBE_READ_REG(hw, IXGBE_PRC511);
	IXGBE_READ_REG(hw, IXGBE_PRC1023);
	IXGBE_READ_REG(hw, IXGBE_PRC1522);
	IXGBE_READ_REG(hw, IXGBE_GPRC);
	IXGBE_READ_REG(hw, IXGBE_BPRC);
	IXGBE_READ_REG(hw, IXGBE_MPRC);
	IXGBE_READ_REG(hw, IXGBE_GPTC);
	IXGBE_READ_REG(hw, IXGBE_GORCL);
	IXGBE_READ_REG(hw, IXGBE_GORCH);
	IXGBE_READ_REG(hw, IXGBE_GOTCL);
	IXGBE_READ_REG(hw, IXGBE_GOTCH);
	for (i = 0; i < 8; i++)
		IXGBE_READ_REG(hw, IXGBE_RNBC(i));
	IXGBE_READ_REG(hw, IXGBE_RUC);
	IXGBE_READ_REG(hw, IXGBE_RFC);
	IXGBE_READ_REG(hw, IXGBE_ROC);
	IXGBE_READ_REG(hw, IXGBE_RJC);
	IXGBE_READ_REG(hw, IXGBE_MNGPRC);
	IXGBE_READ_REG(hw, IXGBE_MNGPDC);
	IXGBE_READ_REG(hw, IXGBE_MNGPTC);
	IXGBE_READ_REG(hw, IXGBE_TORL);
	IXGBE_READ_REG(hw, IXGBE_TORH);
	IXGBE_READ_REG(hw, IXGBE_TPR);
	IXGBE_READ_REG(hw, IXGBE_TPT);
	IXGBE_READ_REG(hw, IXGBE_PTC64);
	IXGBE_READ_REG(hw, IXGBE_PTC127);
	IXGBE_READ_REG(hw, IXGBE_PTC255);
	IXGBE_READ_REG(hw, IXGBE_PTC511);
	IXGBE_READ_REG(hw, IXGBE_PTC1023);
	IXGBE_READ_REG(hw, IXGBE_PTC1522);
	IXGBE_READ_REG(hw, IXGBE_MPTC);
	IXGBE_READ_REG(hw, IXGBE_BPTC);
	for (i = 0; i < 16; i++) {
		IXGBE_READ_REG(hw, IXGBE_QPRC(i));
		IXGBE_READ_REG(hw, IXGBE_QBRC(i));
		IXGBE_READ_REG(hw, IXGBE_QPTC(i));
		IXGBE_READ_REG(hw, IXGBE_QBTC(i));
	}

	return 0;
}

/**
 *  ixgbe_read_pba_num_generic - Reads part number from EEPROM
 *  @hw: pointer to hardware structure
 *  @pba_num: stores the part number from the EEPROM
 *
 *  Reads the part number from the EEPROM.
 **/
s32 ixgbe_read_pba_num_generic(struct ixgbe_hw *hw, u32 *pba_num)
{
	s32 ret_val;
	u16 data;

	ret_val = hw->eeprom.ops.read(hw, IXGBE_PBANUM0_PTR, &data);
	if (ret_val) {
		hw_dbg(hw, "NVM Read Error\n");
		return ret_val;
	}
	*pba_num = (u32)(data << 16);

	ret_val = hw->eeprom.ops.read(hw, IXGBE_PBANUM1_PTR, &data);
	if (ret_val) {
		hw_dbg(hw, "NVM Read Error\n");
		return ret_val;
	}
	*pba_num |= data;

	return 0;
}

/**
 *  ixgbe_get_mac_addr_generic - Generic get MAC address
 *  @hw: pointer to hardware structure
 *  @mac_addr: Adapter MAC address
 *
 *  Reads the adapter's MAC address from first Receive Address Register (RAR0)
 *  A reset of the adapter must be performed prior to calling this function
 *  in order for the MAC address to have been loaded from the EEPROM into RAR0
 **/
s32 ixgbe_get_mac_addr_generic(struct ixgbe_hw *hw, u8 *mac_addr)
{
	u32 rar_high;
	u32 rar_low;
	u16 i;

	rar_high = IXGBE_READ_REG(hw, IXGBE_RAH(0));
	rar_low = IXGBE_READ_REG(hw, IXGBE_RAL(0));

	for (i = 0; i < 4; i++)
		mac_addr[i] = (u8)(rar_low >> (i*8));

	for (i = 0; i < 2; i++)
		mac_addr[i+4] = (u8)(rar_high >> (i*8));

	return 0;
}

/**
 *  ixgbe_get_bus_info_generic - Generic set PCI bus info
 *  @hw: pointer to hardware structure
 *
 *  Sets the PCI bus info (speed, width, type) within the ixgbe_hw structure
 **/
s32 ixgbe_get_bus_info_generic(struct ixgbe_hw *hw)
{
	struct ixgbe_adapter *adapter = hw->back;
	struct ixgbe_mac_info *mac = &hw->mac;
	u16 link_status;

	hw->bus.type = ixgbe_bus_type_pci_express;

	/* Get the negotiated link width and speed from PCI config space */
	pci_read_config_word(adapter->pdev, IXGBE_PCI_LINK_STATUS,
	                     &link_status);

	switch (link_status & IXGBE_PCI_LINK_WIDTH) {
	case IXGBE_PCI_LINK_WIDTH_1:
		hw->bus.width = ixgbe_bus_width_pcie_x1;
		break;
	case IXGBE_PCI_LINK_WIDTH_2:
		hw->bus.width = ixgbe_bus_width_pcie_x2;
		break;
	case IXGBE_PCI_LINK_WIDTH_4:
		hw->bus.width = ixgbe_bus_width_pcie_x4;
		break;
	case IXGBE_PCI_LINK_WIDTH_8:
		hw->bus.width = ixgbe_bus_width_pcie_x8;
		break;
	default:
		hw->bus.width = ixgbe_bus_width_unknown;
		break;
	}

	switch (link_status & IXGBE_PCI_LINK_SPEED) {
	case IXGBE_PCI_LINK_SPEED_2500:
		hw->bus.speed = ixgbe_bus_speed_2500;
		break;
	case IXGBE_PCI_LINK_SPEED_5000:
		hw->bus.speed = ixgbe_bus_speed_5000;
		break;
	default:
		hw->bus.speed = ixgbe_bus_speed_unknown;
		break;
	}

	mac->ops.set_lan_id(hw);

	return 0;
}

/**
 *  ixgbe_set_lan_id_multi_port_pcie - Set LAN id for PCIe multiple port devices
 *  @hw: pointer to the HW structure
 *
 *  Determines the LAN function id by reading memory-mapped registers
 *  and swaps the port value if requested.
 **/
void ixgbe_set_lan_id_multi_port_pcie(struct ixgbe_hw *hw)
{
	struct ixgbe_bus_info *bus = &hw->bus;
	u32 reg;

	reg = IXGBE_READ_REG(hw, IXGBE_STATUS);
	bus->func = (reg & IXGBE_STATUS_LAN_ID) >> IXGBE_STATUS_LAN_ID_SHIFT;
	bus->lan_id = bus->func;

	/* check for a port swap */
	reg = IXGBE_READ_REG(hw, IXGBE_FACTPS);
	if (reg & IXGBE_FACTPS_LFS)
		bus->func ^= 0x1;
}

/**
 *  ixgbe_stop_adapter_generic - Generic stop Tx/Rx units
 *  @hw: pointer to hardware structure
 *
 *  Sets the adapter_stopped flag within ixgbe_hw struct. Clears interrupts,
 *  disables transmit and receive units. The adapter_stopped flag is used by
 *  the shared code and drivers to determine if the adapter is in a stopped
 *  state and should not touch the hardware.
 **/
s32 ixgbe_stop_adapter_generic(struct ixgbe_hw *hw)
{
	u32 number_of_queues;
	u32 reg_val;
	u16 i;

	/*
	 * Set the adapter_stopped flag so other driver functions stop touching
	 * the hardware
	 */
	hw->adapter_stopped = true;

	/* Disable the receive unit */
	reg_val = IXGBE_READ_REG(hw, IXGBE_RXCTRL);
	reg_val &= ~(IXGBE_RXCTRL_RXEN);
	IXGBE_WRITE_REG(hw, IXGBE_RXCTRL, reg_val);
	IXGBE_WRITE_FLUSH(hw);
	msleep(2);

	/* Clear interrupt mask to stop from interrupts being generated */
	IXGBE_WRITE_REG(hw, IXGBE_EIMC, IXGBE_IRQ_CLEAR_MASK);

	/* Clear any pending interrupts */
	IXGBE_READ_REG(hw, IXGBE_EICR);

	/* Disable the transmit unit.  Each queue must be disabled. */
	number_of_queues = hw->mac.max_tx_queues;
	for (i = 0; i < number_of_queues; i++) {
		reg_val = IXGBE_READ_REG(hw, IXGBE_TXDCTL(i));
		if (reg_val & IXGBE_TXDCTL_ENABLE) {
			reg_val &= ~IXGBE_TXDCTL_ENABLE;
			IXGBE_WRITE_REG(hw, IXGBE_TXDCTL(i), reg_val);
		}
	}

	/*
	 * Prevent the PCI-E bus from from hanging by disabling PCI-E master
	 * access and verify no pending requests
	 */
	if (ixgbe_disable_pcie_master(hw) != 0)
		hw_dbg(hw, "PCI-E Master disable polling has failed.\n");

	return 0;
}

/**
 *  ixgbe_led_on_generic - Turns on the software controllable LEDs.
 *  @hw: pointer to hardware structure
 *  @index: led number to turn on
 **/
s32 ixgbe_led_on_generic(struct ixgbe_hw *hw, u32 index)
{
	u32 led_reg = IXGBE_READ_REG(hw, IXGBE_LEDCTL);

	/* To turn on the LED, set mode to ON. */
	led_reg &= ~IXGBE_LED_MODE_MASK(index);
	led_reg |= IXGBE_LED_ON << IXGBE_LED_MODE_SHIFT(index);
	IXGBE_WRITE_REG(hw, IXGBE_LEDCTL, led_reg);
	IXGBE_WRITE_FLUSH(hw);

	return 0;
}

/**
 *  ixgbe_led_off_generic - Turns off the software controllable LEDs.
 *  @hw: pointer to hardware structure
 *  @index: led number to turn off
 **/
s32 ixgbe_led_off_generic(struct ixgbe_hw *hw, u32 index)
{
	u32 led_reg = IXGBE_READ_REG(hw, IXGBE_LEDCTL);

	/* To turn off the LED, set mode to OFF. */
	led_reg &= ~IXGBE_LED_MODE_MASK(index);
	led_reg |= IXGBE_LED_OFF << IXGBE_LED_MODE_SHIFT(index);
	IXGBE_WRITE_REG(hw, IXGBE_LEDCTL, led_reg);
	IXGBE_WRITE_FLUSH(hw);

	return 0;
}

/**
 *  ixgbe_init_eeprom_params_generic - Initialize EEPROM params
 *  @hw: pointer to hardware structure
 *
 *  Initializes the EEPROM parameters ixgbe_eeprom_info within the
 *  ixgbe_hw struct in order to set up EEPROM access.
 **/
s32 ixgbe_init_eeprom_params_generic(struct ixgbe_hw *hw)
{
	struct ixgbe_eeprom_info *eeprom = &hw->eeprom;
	u32 eec;
	u16 eeprom_size;

	if (eeprom->type == ixgbe_eeprom_uninitialized) {
		eeprom->type = ixgbe_eeprom_none;
		/* Set default semaphore delay to 10ms which is a well
		 * tested value */
		eeprom->semaphore_delay = 10;

		/*
		 * Check for EEPROM present first.
		 * If not present leave as none
		 */
		eec = IXGBE_READ_REG(hw, IXGBE_EEC);
		if (eec & IXGBE_EEC_PRES) {
			eeprom->type = ixgbe_eeprom_spi;

			/*
			 * SPI EEPROM is assumed here.  This code would need to
			 * change if a future EEPROM is not SPI.
			 */
			eeprom_size = (u16)((eec & IXGBE_EEC_SIZE) >>
					    IXGBE_EEC_SIZE_SHIFT);
			eeprom->word_size = 1 << (eeprom_size +
						  IXGBE_EEPROM_WORD_SIZE_SHIFT);
		}

		if (eec & IXGBE_EEC_ADDR_SIZE)
			eeprom->address_bits = 16;
		else
			eeprom->address_bits = 8;
		hw_dbg(hw, "Eeprom params: type = %d, size = %d, address bits: "
			  "%d\n", eeprom->type, eeprom->word_size,
			  eeprom->address_bits);
	}

	return 0;
}

/**
 *  ixgbe_write_eeprom_generic - Writes 16 bit value to EEPROM
 *  @hw: pointer to hardware structure
 *  @offset: offset within the EEPROM to be written to
 *  @data: 16 bit word to be written to the EEPROM
 *
 *  If ixgbe_eeprom_update_checksum is not called after this function, the
 *  EEPROM will most likely contain an invalid checksum.
 **/
s32 ixgbe_write_eeprom_generic(struct ixgbe_hw *hw, u16 offset, u16 data)
{
	s32 status;
	u8 write_opcode = IXGBE_EEPROM_WRITE_OPCODE_SPI;

	hw->eeprom.ops.init_params(hw);

	if (offset >= hw->eeprom.word_size) {
		status = IXGBE_ERR_EEPROM;
		goto out;
	}

	/* Prepare the EEPROM for writing  */
	status = ixgbe_acquire_eeprom(hw);

	if (status == 0) {
		if (ixgbe_ready_eeprom(hw) != 0) {
			ixgbe_release_eeprom(hw);
			status = IXGBE_ERR_EEPROM;
		}
	}

	if (status == 0) {
		ixgbe_standby_eeprom(hw);

		/*  Send the WRITE ENABLE command (8 bit opcode )  */
		ixgbe_shift_out_eeprom_bits(hw, IXGBE_EEPROM_WREN_OPCODE_SPI,
		                            IXGBE_EEPROM_OPCODE_BITS);

		ixgbe_standby_eeprom(hw);

		/*
		 * Some SPI eeproms use the 8th address bit embedded in the
		 * opcode
		 */
		if ((hw->eeprom.address_bits == 8) && (offset >= 128))
			write_opcode |= IXGBE_EEPROM_A8_OPCODE_SPI;

		/* Send the Write command (8-bit opcode + addr) */
		ixgbe_shift_out_eeprom_bits(hw, write_opcode,
		                            IXGBE_EEPROM_OPCODE_BITS);
		ixgbe_shift_out_eeprom_bits(hw, (u16)(offset*2),
		                            hw->eeprom.address_bits);

		/* Send the data */
		data = (data >> 8) | (data << 8);
		ixgbe_shift_out_eeprom_bits(hw, data, 16);
		ixgbe_standby_eeprom(hw);

		msleep(hw->eeprom.semaphore_delay);
		/* Done with writing - release the EEPROM */
		ixgbe_release_eeprom(hw);
	}

out:
	return status;
}

/**
 *  ixgbe_read_eeprom_bit_bang_generic - Read EEPROM word using bit-bang
 *  @hw: pointer to hardware structure
 *  @offset: offset within the EEPROM to be read
 *  @data: read 16 bit value from EEPROM
 *
 *  Reads 16 bit value from EEPROM through bit-bang method
 **/
s32 ixgbe_read_eeprom_bit_bang_generic(struct ixgbe_hw *hw, u16 offset,
                                       u16 *data)
{
	s32 status;
	u16 word_in;
	u8 read_opcode = IXGBE_EEPROM_READ_OPCODE_SPI;

	hw->eeprom.ops.init_params(hw);

	if (offset >= hw->eeprom.word_size) {
		status = IXGBE_ERR_EEPROM;
		goto out;
	}

	/* Prepare the EEPROM for reading  */
	status = ixgbe_acquire_eeprom(hw);

	if (status == 0) {
		if (ixgbe_ready_eeprom(hw) != 0) {
			ixgbe_release_eeprom(hw);
			status = IXGBE_ERR_EEPROM;
		}
	}

	if (status == 0) {
		ixgbe_standby_eeprom(hw);

		/*
		 * Some SPI eeproms use the 8th address bit embedded in the
		 * opcode
		 */
		if ((hw->eeprom.address_bits == 8) && (offset >= 128))
			read_opcode |= IXGBE_EEPROM_A8_OPCODE_SPI;

		/* Send the READ command (opcode + addr) */
		ixgbe_shift_out_eeprom_bits(hw, read_opcode,
		                            IXGBE_EEPROM_OPCODE_BITS);
		ixgbe_shift_out_eeprom_bits(hw, (u16)(offset*2),
		                            hw->eeprom.address_bits);

		/* Read the data. */
		word_in = ixgbe_shift_in_eeprom_bits(hw, 16);
		*data = (word_in >> 8) | (word_in << 8);

		/* End this read operation */
		ixgbe_release_eeprom(hw);
	}

out:
	return status;
}

/**
 *  ixgbe_read_eeprom_generic - Read EEPROM word using EERD
 *  @hw: pointer to hardware structure
 *  @offset: offset of  word in the EEPROM to read
 *  @data: word read from the EEPROM
 *
 *  Reads a 16 bit word from the EEPROM using the EERD register.
 **/
s32 ixgbe_read_eeprom_generic(struct ixgbe_hw *hw, u16 offset, u16 *data)
{
	u32 eerd;
	s32 status;

	hw->eeprom.ops.init_params(hw);

	if (offset >= hw->eeprom.word_size) {
		status = IXGBE_ERR_EEPROM;
		goto out;
	}

	eerd = (offset << IXGBE_EEPROM_READ_ADDR_SHIFT) +
	       IXGBE_EEPROM_READ_REG_START;

	IXGBE_WRITE_REG(hw, IXGBE_EERD, eerd);
	status = ixgbe_poll_eeprom_eerd_done(hw);

	if (status == 0)
		*data = (IXGBE_READ_REG(hw, IXGBE_EERD) >>
		         IXGBE_EEPROM_READ_REG_DATA);
	else
		hw_dbg(hw, "Eeprom read timed out\n");

out:
	return status;
}

/**
 *  ixgbe_poll_eeprom_eerd_done - Poll EERD status
 *  @hw: pointer to hardware structure
 *
 *  Polls the status bit (bit 1) of the EERD to determine when the read is done.
 **/
static s32 ixgbe_poll_eeprom_eerd_done(struct ixgbe_hw *hw)
{
	u32 i;
	u32 reg;
	s32 status = IXGBE_ERR_EEPROM;

	for (i = 0; i < IXGBE_EERD_ATTEMPTS; i++) {
		reg = IXGBE_READ_REG(hw, IXGBE_EERD);
		if (reg & IXGBE_EEPROM_READ_REG_DONE) {
			status = 0;
			break;
		}
		udelay(5);
	}
	return status;
}

/**
 *  ixgbe_acquire_eeprom - Acquire EEPROM using bit-bang
 *  @hw: pointer to hardware structure
 *
 *  Prepares EEPROM for access using bit-bang method. This function should
 *  be called before issuing a command to the EEPROM.
 **/
static s32 ixgbe_acquire_eeprom(struct ixgbe_hw *hw)
{
	s32 status = 0;
	u32 eec = 0;
	u32 i;

	if (ixgbe_acquire_swfw_sync(hw, IXGBE_GSSR_EEP_SM) != 0)
		status = IXGBE_ERR_SWFW_SYNC;

	if (status == 0) {
		eec = IXGBE_READ_REG(hw, IXGBE_EEC);

		/* Request EEPROM Access */
		eec |= IXGBE_EEC_REQ;
		IXGBE_WRITE_REG(hw, IXGBE_EEC, eec);

		for (i = 0; i < IXGBE_EEPROM_GRANT_ATTEMPTS; i++) {
			eec = IXGBE_READ_REG(hw, IXGBE_EEC);
			if (eec & IXGBE_EEC_GNT)
				break;
			udelay(5);
		}

		/* Release if grant not acquired */
		if (!(eec & IXGBE_EEC_GNT)) {
			eec &= ~IXGBE_EEC_REQ;
			IXGBE_WRITE_REG(hw, IXGBE_EEC, eec);
			hw_dbg(hw, "Could not acquire EEPROM grant\n");

			ixgbe_release_swfw_sync(hw, IXGBE_GSSR_EEP_SM);
			status = IXGBE_ERR_EEPROM;
		}
	}

	/* Setup EEPROM for Read/Write */
	if (status == 0) {
		/* Clear CS and SK */
		eec &= ~(IXGBE_EEC_CS | IXGBE_EEC_SK);
		IXGBE_WRITE_REG(hw, IXGBE_EEC, eec);
		IXGBE_WRITE_FLUSH(hw);
		udelay(1);
	}
	return status;
}

/**
 *  ixgbe_get_eeprom_semaphore - Get hardware semaphore
 *  @hw: pointer to hardware structure
 *
 *  Sets the hardware semaphores so EEPROM access can occur for bit-bang method
 **/
static s32 ixgbe_get_eeprom_semaphore(struct ixgbe_hw *hw)
{
	s32 status = IXGBE_ERR_EEPROM;
	u32 timeout;
	u32 i;
	u32 swsm;

	/* Set timeout value based on size of EEPROM */
	timeout = hw->eeprom.word_size + 1;

	/* Get SMBI software semaphore between device drivers first */
	for (i = 0; i < timeout; i++) {
		/*
		 * If the SMBI bit is 0 when we read it, then the bit will be
		 * set and we have the semaphore
		 */
		swsm = IXGBE_READ_REG(hw, IXGBE_SWSM);
		if (!(swsm & IXGBE_SWSM_SMBI)) {
			status = 0;
			break;
		}
		msleep(1);
	}

	/* Now get the semaphore between SW/FW through the SWESMBI bit */
	if (status == 0) {
		for (i = 0; i < timeout; i++) {
			swsm = IXGBE_READ_REG(hw, IXGBE_SWSM);

			/* Set the SW EEPROM semaphore bit to request access */
			swsm |= IXGBE_SWSM_SWESMBI;
			IXGBE_WRITE_REG(hw, IXGBE_SWSM, swsm);

			/*
			 * If we set the bit successfully then we got the
			 * semaphore.
			 */
			swsm = IXGBE_READ_REG(hw, IXGBE_SWSM);
			if (swsm & IXGBE_SWSM_SWESMBI)
				break;

			udelay(50);
		}

		/*
		 * Release semaphores and return error if SW EEPROM semaphore
		 * was not granted because we don't have access to the EEPROM
		 */
		if (i >= timeout) {
			hw_dbg(hw, "Driver can't access the Eeprom - Semaphore "
			       "not granted.\n");
			ixgbe_release_eeprom_semaphore(hw);
			status = IXGBE_ERR_EEPROM;
		}
	}

	return status;
}

/**
 *  ixgbe_release_eeprom_semaphore - Release hardware semaphore
 *  @hw: pointer to hardware structure
 *
 *  This function clears hardware semaphore bits.
 **/
static void ixgbe_release_eeprom_semaphore(struct ixgbe_hw *hw)
{
	u32 swsm;

	swsm = IXGBE_READ_REG(hw, IXGBE_SWSM);

	/* Release both semaphores by writing 0 to the bits SWESMBI and SMBI */
	swsm &= ~(IXGBE_SWSM_SWESMBI | IXGBE_SWSM_SMBI);
	IXGBE_WRITE_REG(hw, IXGBE_SWSM, swsm);
	IXGBE_WRITE_FLUSH(hw);
}

/**
 *  ixgbe_ready_eeprom - Polls for EEPROM ready
 *  @hw: pointer to hardware structure
 **/
static s32 ixgbe_ready_eeprom(struct ixgbe_hw *hw)
{
	s32 status = 0;
	u16 i;
	u8 spi_stat_reg;

	/*
	 * Read "Status Register" repeatedly until the LSB is cleared.  The
	 * EEPROM will signal that the command has been completed by clearing
	 * bit 0 of the internal status register.  If it's not cleared within
	 * 5 milliseconds, then error out.
	 */
	for (i = 0; i < IXGBE_EEPROM_MAX_RETRY_SPI; i += 5) {
		ixgbe_shift_out_eeprom_bits(hw, IXGBE_EEPROM_RDSR_OPCODE_SPI,
		                            IXGBE_EEPROM_OPCODE_BITS);
		spi_stat_reg = (u8)ixgbe_shift_in_eeprom_bits(hw, 8);
		if (!(spi_stat_reg & IXGBE_EEPROM_STATUS_RDY_SPI))
			break;

		udelay(5);
		ixgbe_standby_eeprom(hw);
	};

	/*
	 * On some parts, SPI write time could vary from 0-20mSec on 3.3V
	 * devices (and only 0-5mSec on 5V devices)
	 */
	if (i >= IXGBE_EEPROM_MAX_RETRY_SPI) {
		hw_dbg(hw, "SPI EEPROM Status error\n");
		status = IXGBE_ERR_EEPROM;
	}

	return status;
}

/**
 *  ixgbe_standby_eeprom - Returns EEPROM to a "standby" state
 *  @hw: pointer to hardware structure
 **/
static void ixgbe_standby_eeprom(struct ixgbe_hw *hw)
{
	u32 eec;

	eec = IXGBE_READ_REG(hw, IXGBE_EEC);

	/* Toggle CS to flush commands */
	eec |= IXGBE_EEC_CS;
	IXGBE_WRITE_REG(hw, IXGBE_EEC, eec);
	IXGBE_WRITE_FLUSH(hw);
	udelay(1);
	eec &= ~IXGBE_EEC_CS;
	IXGBE_WRITE_REG(hw, IXGBE_EEC, eec);
	IXGBE_WRITE_FLUSH(hw);
	udelay(1);
}

/**
 *  ixgbe_shift_out_eeprom_bits - Shift data bits out to the EEPROM.
 *  @hw: pointer to hardware structure
 *  @data: data to send to the EEPROM
 *  @count: number of bits to shift out
 **/
static void ixgbe_shift_out_eeprom_bits(struct ixgbe_hw *hw, u16 data,
                                        u16 count)
{
	u32 eec;
	u32 mask;
	u32 i;

	eec = IXGBE_READ_REG(hw, IXGBE_EEC);

	/*
	 * Mask is used to shift "count" bits of "data" out to the EEPROM
	 * one bit at a time.  Determine the starting bit based on count
	 */
	mask = 0x01 << (count - 1);

	for (i = 0; i < count; i++) {
		/*
		 * A "1" is shifted out to the EEPROM by setting bit "DI" to a
		 * "1", and then raising and then lowering the clock (the SK
		 * bit controls the clock input to the EEPROM).  A "0" is
		 * shifted out to the EEPROM by setting "DI" to "0" and then
		 * raising and then lowering the clock.
		 */
		if (data & mask)
			eec |= IXGBE_EEC_DI;
		else
			eec &= ~IXGBE_EEC_DI;

		IXGBE_WRITE_REG(hw, IXGBE_EEC, eec);
		IXGBE_WRITE_FLUSH(hw);

		udelay(1);

		ixgbe_raise_eeprom_clk(hw, &eec);
		ixgbe_lower_eeprom_clk(hw, &eec);

		/*
		 * Shift mask to signify next bit of data to shift in to the
		 * EEPROM
		 */
		mask = mask >> 1;
	};

	/* We leave the "DI" bit set to "0" when we leave this routine. */
	eec &= ~IXGBE_EEC_DI;
	IXGBE_WRITE_REG(hw, IXGBE_EEC, eec);
	IXGBE_WRITE_FLUSH(hw);
}

/**
 *  ixgbe_shift_in_eeprom_bits - Shift data bits in from the EEPROM
 *  @hw: pointer to hardware structure
 **/
static u16 ixgbe_shift_in_eeprom_bits(struct ixgbe_hw *hw, u16 count)
{
	u32 eec;
	u32 i;
	u16 data = 0;

	/*
	 * In order to read a register from the EEPROM, we need to shift
	 * 'count' bits in from the EEPROM. Bits are "shifted in" by raising
	 * the clock input to the EEPROM (setting the SK bit), and then reading
	 * the value of the "DO" bit.  During this "shifting in" process the
	 * "DI" bit should always be clear.
	 */
	eec = IXGBE_READ_REG(hw, IXGBE_EEC);

	eec &= ~(IXGBE_EEC_DO | IXGBE_EEC_DI);

	for (i = 0; i < count; i++) {
		data = data << 1;
		ixgbe_raise_eeprom_clk(hw, &eec);

		eec = IXGBE_READ_REG(hw, IXGBE_EEC);

		eec &= ~(IXGBE_EEC_DI);
		if (eec & IXGBE_EEC_DO)
			data |= 1;

		ixgbe_lower_eeprom_clk(hw, &eec);
	}

	return data;
}

/**
 *  ixgbe_raise_eeprom_clk - Raises the EEPROM's clock input.
 *  @hw: pointer to hardware structure
 *  @eec: EEC register's current value
 **/
static void ixgbe_raise_eeprom_clk(struct ixgbe_hw *hw, u32 *eec)
{
	/*
	 * Raise the clock input to the EEPROM
	 * (setting the SK bit), then delay
	 */
	*eec = *eec | IXGBE_EEC_SK;
	IXGBE_WRITE_REG(hw, IXGBE_EEC, *eec);
	IXGBE_WRITE_FLUSH(hw);
	udelay(1);
}

/**
 *  ixgbe_lower_eeprom_clk - Lowers the EEPROM's clock input.
 *  @hw: pointer to hardware structure
 *  @eecd: EECD's current value
 **/
static void ixgbe_lower_eeprom_clk(struct ixgbe_hw *hw, u32 *eec)
{
	/*
	 * Lower the clock input to the EEPROM (clearing the SK bit), then
	 * delay
	 */
	*eec = *eec & ~IXGBE_EEC_SK;
	IXGBE_WRITE_REG(hw, IXGBE_EEC, *eec);
	IXGBE_WRITE_FLUSH(hw);
	udelay(1);
}

/**
 *  ixgbe_release_eeprom - Release EEPROM, release semaphores
 *  @hw: pointer to hardware structure
 **/
static void ixgbe_release_eeprom(struct ixgbe_hw *hw)
{
	u32 eec;

	eec = IXGBE_READ_REG(hw, IXGBE_EEC);

	eec |= IXGBE_EEC_CS;  /* Pull CS high */
	eec &= ~IXGBE_EEC_SK; /* Lower SCK */

	IXGBE_WRITE_REG(hw, IXGBE_EEC, eec);
	IXGBE_WRITE_FLUSH(hw);

	udelay(1);

	/* Stop requesting EEPROM access */
	eec &= ~IXGBE_EEC_REQ;
	IXGBE_WRITE_REG(hw, IXGBE_EEC, eec);

	ixgbe_release_swfw_sync(hw, IXGBE_GSSR_EEP_SM);