text: // SPDX-License-Identifier: GPL-2.0
  /* Copyright(c) 1999 - 2018 Intel Corporation. */
  
  #include "e1000.h"
  
  /**
   *  e1000_raise_eec_clk - Raise EEPROM clock
   *  @hw: pointer to the HW structure
   *  @eecd: pointer to the EEPROM
   *
   *  Enable/Raise the EEPROM clock bit.
   **/
  static void e1000_raise_eec_clk(struct e1000_hw *hw, u32 *eecd)
  {
  	*eecd = *eecd | E1000_EECD_SK;
  	ew32(EECD, *eecd);
  	e1e_flush();
  	udelay(hw->nvm.delay_usec);
  }
  
  /**
   *  e1000_lower_eec_clk - Lower EEPROM clock
   *  @hw: pointer to the HW structure
   *  @eecd: pointer to the EEPROM
   *
   *  Clear/Lower the EEPROM clock bit.
   **/
  static void e1000_lower_eec_clk(struct e1000_hw *hw, u32 *eecd)
  {
  	*eecd = *eecd & ~E1000_EECD_SK;
  	ew32(EECD, *eecd);
  	e1e_flush();
  	udelay(hw->nvm.delay_usec);
  }
  
  /**
   *  e1000_shift_out_eec_bits - Shift data bits our to the EEPROM
   *  @hw: pointer to the HW structure
   *  @data: data to send to the EEPROM
   *  @count: number of bits to shift out
   *
   *  We need to shift 'count' bits out to the EEPROM.  So, the value in the
   *  "data" parameter will be shifted out to the EEPROM one bit at a time.
   *  In order to do this, "data" must be broken down into bits.
   **/
  static void e1000_shift_out_eec_bits(struct e1000_hw *hw, u16 data, u16 count)
  {
  	struct e1000_nvm_info *nvm = &hw->nvm;
  	u32 eecd = er32(EECD);
  	u32 mask;
  
  	mask = BIT(count - 1);
  	if (nvm->type == e1000_nvm_eeprom_spi)
  		eecd |= E1000_EECD_DO;
  
  	do {
  		eecd &= ~E1000_EECD_DI;
  
  		if (data & mask)
  			eecd |= E1000_EECD_DI;
  
  		ew32(EECD, eecd);
  		e1e_flush();
  
  		udelay(nvm->delay_usec);
  
  		e1000_raise_eec_clk(hw, &eecd);
  		e1000_lower_eec_clk(hw, &eecd);
  
  		mask >>= 1;
  	} while (mask);
  
  	eecd &= ~E1000_EECD_DI;
  	ew32(EECD, eecd);
  }
  
  /**
   *  e1000_shift_in_eec_bits - Shift data bits in from the EEPROM
   *  @hw: pointer to the HW structure
   *  @count: number of bits to shift in
   *
   *  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 data out
   *  "DO" bit.  During this "shifting in" process the data in "DI" bit should
   *  always be clear.
   **/
  static u16 e1000_shift_in_eec_bits(struct e1000_hw *hw, u16 count)
  {
  	u32 eecd;
  	u32 i;
  	u16 data;
  
  	eecd = er32(EECD);
  	eecd &= ~(E1000_EECD_DO | E1000_EECD_DI);
  	data = 0;
  
  	for (i = 0; i < count; i++) {
  		data <<= 1;
  		e1000_raise_eec_clk(hw, &eecd);
  
  		eecd = er32(EECD);
  
  		eecd &= ~E1000_EECD_DI;
  		if (eecd & E1000_EECD_DO)
  			data |= 1;
  
  		e1000_lower_eec_clk(hw, &eecd);
  	}
  
  	return data;
  }
  
  /**
   *  e1000e_poll_eerd_eewr_done - Poll for EEPROM read/write completion
   *  @hw: pointer to the HW structure
   *  @ee_reg: EEPROM flag for polling
   *
   *  Polls the EEPROM status bit for either read or write completion based
   *  upon the value of 'ee_reg'.
   **/
  s32 e1000e_poll_eerd_eewr_done(struct e1000_hw *hw, int ee_reg)
  {
  	u32 attempts = 100000;
  	u32 i, reg = 0;
  
  	for (i = 0; i < attempts; i++) {
  		if (ee_reg == E1000_NVM_POLL_READ)
  			reg = er32(EERD);
  		else
  			reg = er32(EEWR);
  
  		if (reg & E1000_NVM_RW_REG_DONE)
  			return 0;
  
  		udelay(5);
  	}
  
  	return -E1000_ERR_NVM;
  }
  
  /**
   *  e1000e_acquire_nvm - Generic request for access to EEPROM
   *  @hw: pointer to the HW structure
   *
   *  Set the EEPROM access request bit and wait for EEPROM access grant bit.
   *  Return successful if access grant bit set, else clear the request for
   *  EEPROM access and return -E1000_ERR_NVM (-1).
   **/
  s32 e1000e_acquire_nvm(struct e1000_hw *hw)
  {
  	u32 eecd = er32(EECD);
  	s32 timeout = E1000_NVM_GRANT_ATTEMPTS;
  
  	ew32(EECD, eecd | E1000_EECD_REQ);
  	eecd = er32(EECD);
  
  	while (timeout) {
  		if (eecd & E1000_EECD_GNT)
  			break;
  		udelay(5);
  		eecd = er32(EECD);
  		timeout--;
  	}
  
  	if (!timeout) {
  		eecd &= ~E1000_EECD_REQ;
  		ew32(EECD, eecd);
  		e_dbg("Could not acquire NVM grant\n");
  		return -E1000_ERR_NVM;
  	}
  
  	return 0;
  }
  
  /**
   *  e1000_standby_nvm - Return EEPROM to standby state
   *  @hw: pointer to the HW structure
   *
   *  Return the EEPROM to a standby state.
   **/
  static void e1000_standby_nvm(struct e1000_hw *hw)
  {
  	struct e1000_nvm_info *nvm = &hw->nvm;
  	u32 eecd = er32(EECD);
  
  	if (nvm->type == e1000_nvm_eeprom_spi) {
  		/* Toggle CS to flush commands */
  		eecd |= E1000_EECD_CS;
  		ew32(EECD, eecd);
  		e1e_flush();
  		udelay(nvm->delay_usec);
  		eecd &= ~E1000_EECD_CS;
  		ew32(EECD, eecd);
  		e1e_flush();
  		udelay(nvm->delay_usec);
  	}
  }
  
  /**
   *  e1000_stop_nvm - Terminate EEPROM command
   *  @hw: pointer to the HW structure
   *
   *  Terminates the current command by inverting the EEPROM's chip select pin.
   **/
  static void e1000_stop_nvm(struct e1000_hw *hw)
  {
  	u32 eecd;
  
  	eecd = er32(EECD);
  	if (hw->nvm.type == e1000_nvm_eeprom_spi) {
  		/* Pull CS high */
  		eecd |= E1000_EECD_CS;
  		e1000_lower_eec_clk(hw, &eecd);
  	}
  }
  
  /**
   *  e1000e_release_nvm - Release exclusive access to EEPROM
   *  @hw: pointer to the HW structure
   *
   *  Stop any current commands to the EEPROM and clear the EEPROM request bit.
   **/
  void e1000e_release_nvm(struct e1000_hw *hw)
  {
  	u32 eecd;
  
  	e1000_stop_nvm(hw);
  
  	eecd = er32(EECD);
  	eecd &= ~E1000_EECD_REQ;
  	ew32(EECD, eecd);
  }
  
  /**
   *  e1000_ready_nvm_eeprom - Prepares EEPROM for read/write
   *  @hw: pointer to the HW structure
   *
   *  Setups the EEPROM for reading and writing.
   **/
  static s32 e1000_ready_nvm_eeprom(struct e1000_hw *hw)
  {
  	struct e1000_nvm_info *nvm = &hw->nvm;
  	u32 eecd = er32(EECD);
  	u8 spi_stat_reg;
  
  	if (nvm->type == e1000_nvm_eeprom_spi) {
  		u16 timeout = NVM_MAX_RETRY_SPI;
  
  		/* Clear SK and CS */
  		eecd &= ~(E1000_EECD_CS | E1000_EECD_SK);
  		ew32(EECD, eecd);
  		e1e_flush();
  		udelay(1);
  
  		/* 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 'timeout', then error out.
  		 */
  		while (timeout) {
  			e1000_shift_out_eec_bits(hw, NVM_RDSR_OPCODE_SPI,
  						 hw->nvm.opcode_bits);
  			spi_stat_reg = (u8)e1000_shift_in_eec_bits(hw, 8);
  			if (!(spi_stat_reg & NVM_STATUS_RDY_SPI))
  				break;
  
  			udelay(5);
  			e1000_standby_nvm(hw);
  			timeout--;
  		}
  
  		if (!timeout) {
  			e_dbg("SPI NVM Status error\n");
  			return -E1000_ERR_NVM;
  		}
  	}
  
  	return 0;
  }
  
  /**
   *  e1000e_read_nvm_eerd - Reads EEPROM using EERD register
   *  @hw: pointer to the HW structure
   *  @offset: offset of word in the EEPROM to read
   *  @words: number of words to read
   *  @data: word read from the EEPROM
   *
   *  Reads a 16 bit word from the EEPROM using the EERD register.
   **/
  s32 e1000e_read_nvm_eerd(struct e1000_hw *hw, u16 offset, u16 words, u16 *data)
  {
  	struct e1000_nvm_info *nvm = &hw->nvm;
  	u32 i, eerd = 0;
  	s32 ret_val = 0;
  
  	/* A check for invalid values:  offset too large, too many words,
  	 * too many words for the offset, and not enough words.
  	 */
  	if ((offset >= nvm->word_size) || (words > (nvm->word_size - offset)) ||
  	    (words == 0)) {
  		e_dbg("nvm parameter(s) out of bounds\n");
  		return -E1000_ERR_NVM;
  	}
  
  	for (i = 0; i < words; i++) {
  		eerd = ((offset + i) << E1000_NVM_RW_ADDR_SHIFT) +
  		    E1000_NVM_RW_REG_START;
  
  		ew32(EERD, eerd);
  		ret_val = e1000e_poll_eerd_eewr_done(hw, E1000_NVM_POLL_READ);
  		if (ret_val) {
  			e_dbg("NVM read error: %d\n", ret_val);
  			break;
  		}
  
  		data[i] = (er32(EERD) >> E1000_NVM_RW_REG_DATA);
  	}
  
  	return ret_val;
  }
  
  /**
   *  e1000e_write_nvm_spi - Write to EEPROM using SPI
   *  @hw: pointer to the HW structure
   *  @offset: offset within the EEPROM to be written to
   *  @words: number of words to write
   *  @data: 16 bit word(s) to be written to the EEPROM
   *
   *  Writes data to EEPROM at offset using SPI interface.
   *
   *  If e1000e_update_nvm_checksum is not called after this function , the
   *  EEPROM will most likely contain an invalid checksum.
   **/
  s32 e1000e_write_nvm_spi(struct e1000_hw *hw, u16 offset, u16 words, u16 *data)
  {
  	struct e1000_nvm_info *nvm = &hw->nvm;
  	s32 ret_val = -E1000_ERR_NVM;
  	u16 widx = 0;
  
  	/* A check for invalid values:  offset too large, too many words,
  	 * and not enough words.
  	 */
  	if ((offset >= nvm->word_size) || (words > (nvm->word_size - offset)) ||
  	    (words == 0)) {
  		e_dbg("nvm parameter(s) out of bounds\n");
  		return -E1000_ERR_NVM;
  	}
  
  	while (widx < words) {
  		u8 write_opcode = NVM_WRITE_OPCODE_SPI;
  
  		ret_val = nvm->ops.acquire(hw);
  		if (ret_val)
  			return ret_val;
  
  		ret_val = e1000_ready_nvm_eeprom(hw);
  		if (ret_val) {
  			nvm->ops.release(hw);
  			return ret_val;
  		}
  
  		e1000_standby_nvm(hw);
  
  		/* Send the WRITE ENABLE command (8 bit opcode) */
  		e1000_shift_out_eec_bits(hw, NVM_WREN_OPCODE_SPI,
  					 nvm->opcode_bits);
  
  		e1000_standby_nvm(hw);
  
  		/* Some SPI eeproms use the 8th address bit embedded in the
  		 * opcode
  		 */
  		if ((nvm->address_bits == 8) && (offset >= 128))
  			write_opcode |= NVM_A8_OPCODE_SPI;
  
  		/* Send the Write command (8-bit opcode + addr) */
  		e1000_shift_out_eec_bits(hw, write_opcode, nvm->opcode_bits);
  		e1000_shift_out_eec_bits(hw, (u16)((offset + widx) * 2),
  					 nvm->address_bits);
  
  		/* Loop to allow for up to whole page write of eeprom */
  		while (widx < words) {
  			u16 word_out = data[widx];
  
  			word_out = (word_out >> 8) | (word_out << 8);
  			e1000_shift_out_eec_bits(hw, word_out, 16);
  			widx++;
  
  			if ((((offset + widx) * 2) % nvm->page_size) == 0) {
  				e1000_standby_nvm(hw);
  				break;
  			}
  		}
  		usleep_range(10000, 11000);
  		nvm->ops.release(hw);
  	}
  
  	return ret_val;
  }
  
  /**
   *  e1000_read_pba_string_generic - Read device part number
   *  @hw: pointer to the HW structure
   *  @pba_num: pointer to device part number
   *  @pba_num_size: size of part number buffer
   *
   *  Reads the product board assembly (PBA) number from the EEPROM and stores
   *  the value in pba_num.
   **/
  s32 e1000_read_pba_string_generic(struct e1000_hw *hw, u8 *pba_num,
  				  u32 pba_num_size)
  {
  	s32 ret_val;
  	u16 nvm_data;
  	u16 pba_ptr;
  	u16 offset;
  	u16 length;
  
  	if (pba_num == NULL) {
  		e_dbg("PBA string buffer was null\n");
  		return -E1000_ERR_INVALID_ARGUMENT;
  	}
  
  	ret_val = e1000_read_nvm(hw, NVM_PBA_OFFSET_0, 1, &nvm_data);
  	if (ret_val) {
  		e_dbg("NVM Read Error\n");
  		return ret_val;
  	}
  
  	ret_val = e1000_read_nvm(hw, NVM_PBA_OFFSET_1, 1, &pba_ptr);
  	if (ret_val) {
  		e_dbg("NVM Read Error\n");
  		return ret_val;
  	}
  
  	/* if nvm_data is not ptr guard the PBA must be in legacy format which
  	 * means pba_ptr is actually our second data word for the PBA number
  	 * and we can decode it into an ascii string
  	 */
  	if (nvm_data != NVM_PBA_PTR_GUARD) {
  		e_dbg("NVM PBA number is not stored as string\n");
  
  		/* make sure callers buffer is big enough to store the PBA */
  		if (pba_num_size < E1000_PBANUM_LENGTH) {
  			e_dbg("PBA string buffer too small\n");
  			return E1000_ERR_NO_SPACE;
  		}
  
  		/* extract hex string from data and pba_ptr */
  		pba_num[0] = (nvm_data >> 12) & 0xF;
  		pba_num[1] = (nvm_data >> 8) & 0xF;
  		pba_num[2] = (nvm_data >> 4) & 0xF;
  		pba_num[3] = nvm_data & 0xF;
  		pba_num[4] = (pba_ptr >> 12) & 0xF;
  		pba_num[5] = (pba_ptr >> 8) & 0xF;
  		pba_num[6] = '-';
  		pba_num[7] = 0;
  		pba_num[8] = (pba_ptr >> 4) & 0xF;
  		pba_num[9] = pba_ptr & 0xF;
  
  		/* put a null character on the end of our string */
  		pba_num[10] = '\0';
  
  		/* switch all the data but the '-' to hex char */
  		for (offset = 0; offset < 10; offset++) {
  			if (pba_num[offset] < 0xA)
  				pba_num[offset] += '0';
  			else if (pba_num[offset] < 0x10)
  				pba_num[offset] += 'A' - 0xA;
  		}
  
  		return 0;
  	}
  
  	ret_val = e1000_read_nvm(hw, pba_ptr, 1, &length);
  	if (ret_val) {
  		e_dbg("NVM Read Error\n");
  		return ret_val;
  	}
  
  	if (length == 0xFFFF || length == 0) {
  		e_dbg("NVM PBA number section invalid length\n");
  		return -E1000_ERR_NVM_PBA_SECTION;
  	}
  	/* check if pba_num buffer is big enough */
  	if (pba_num_size < (((u32)length * 2) - 1)) {
  		e_dbg("PBA string buffer too small\n");
  		return -E1000_ERR_NO_SPACE;
  	}
  
  	/* trim pba length from start of string */
  	pba_ptr++;
  	length--;
  
  	for (offset = 0; offset < length; offset++) {
  		ret_val = e1000_read_nvm(hw, pba_ptr + offset, 1, &nvm_data);
  		if (ret_val) {
  			e_dbg("NVM Read Error\n");
  			return ret_val;
  		}
  		pba_num[offset * 2] = (u8)(nvm_data >> 8);
  		pba_num[(offset * 2) + 1] = (u8)(nvm_data & 0xFF);
  	}
  	pba_num[offset * 2] = '\0';
  
  	return 0;
  }
  
  /**
   *  e1000_read_mac_addr_generic - Read device MAC address
   *  @hw: pointer to the HW structure
   *
   *  Reads the device MAC address from the EEPROM and stores the value.
   *  Since devices with two ports use the same EEPROM, we increment the
   *  last bit in the MAC address for the second port.
   **/
  s32 e1000_read_mac_addr_generic(struct e1000_hw *hw)
  {
  	u32 rar_high;
  	u32 rar_low;
  	u16 i;
  
  	rar_high = er32(RAH(0));
  	rar_low = er32(RAL(0));
  
  	for (i = 0; i < E1000_RAL_MAC_ADDR_LEN; i++)
  		hw->mac.perm_addr[i] = (u8)(rar_low >> (i * 8));
  
  	for (i = 0; i < E1000_RAH_MAC_ADDR_LEN; i++)
  		hw->mac.perm_addr[i + 4] = (u8)(rar_high >> (i * 8));
  
  	for (i = 0; i < ETH_ALEN; i++)
  		hw->mac.addr[i] = hw->mac.perm_addr[i];
  
  	return 0;
  }
  
  /**
   *  e1000e_validate_nvm_checksum_generic - Validate EEPROM checksum
   *  @hw: pointer to the HW structure
   *
   *  Calculates the EEPROM checksum by reading/adding each word of the EEPROM
   *  and then verifies that the sum of the EEPROM is equal to 0xBABA.
   **/
  s32 e1000e_validate_nvm_checksum_generic(struct e1000_hw *hw)
  {
  	s32 ret_val;
  	u16 checksum = 0;
  	u16 i, nvm_data;
  
  	for (i = 0; i < (NVM_CHECKSUM_REG + 1); i++) {
  		ret_val = e1000_read_nvm(hw, i, 1, &nvm_data);
  		if (ret_val) {
  			e_dbg("NVM Read Error\n");
  			return ret_val;
  		}
  		checksum += nvm_data;
  	}
  
  	if (checksum != (u16)NVM_SUM) {
  		e_dbg("NVM Checksum Invalid\n");
  		return -E1000_ERR_NVM;
  	}
  
  	return 0;
  }
  
  /**
   *  e1000e_update_nvm_checksum_generic - Update EEPROM checksum
   *  @hw: pointer to the HW structure
   *
   *  Updates the EEPROM checksum by reading/adding each word of the EEPROM
   *  up to the checksum.  Then calculates the EEPROM checksum and writes the
   *  value to the EEPROM.
   **/
  s32 e1000e_update_nvm_checksum_generic(struct e1000_hw *hw)
  {
  	s32 ret_val;
  	u16 checksum = 0;
  	u16 i, nvm_data;
  
  	for (i = 0; i < NVM_CHECKSUM_REG; i++) {
  		ret_val = e1000_read_nvm(hw, i, 1, &nvm_data);
  		if (ret_val) {
  			e_dbg("NVM Read Error while updating checksum.\n");
  			return ret_val;
  		}
  		checksum += nvm_data;
  	}
  	checksum = (u16)NVM_SUM - checksum;
  	ret_val = e1000_write_nvm(hw, NVM_CHECKSUM_REG, 1, &checksum);
  	if (ret_val)
  		e_dbg("NVM Write Error while updating checksum.\n");
  
  	return ret_val;
  }
  
  /**
   *  e1000e_reload_nvm_generic - Reloads EEPROM
   *  @hw: pointer to the HW structure
   *
   *  Reloads the EEPROM by setting the "Reinitialize from EEPROM" bit in the
   *  extended control register.
   **/
  void e1000e_reload_nvm_generic(struct e1000_hw *hw)
  {
  	u32 ctrl_ext;
  
  	usleep_range(10, 20);
  	ctrl_ext = er32(CTRL_EXT);
  	ctrl_ext |= E1000_CTRL_EXT_EE_RST;
  	ew32(CTRL_EXT, ctrl_ext);
  	e1e_flush();
  }
  