board/ruby/ar8237.c - uboot/qsr1000 - Git at Google

 /*
  *  board/ums/ar8237.c
  *
  *  U-Boot driver for the Atheros 8237 switch.
  *
  *  Copyright (c) Quantenna Communications Incorporated 2009.
  *  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  *
  */

 /********************************************************************
     Atheros 8237 MDIO programming details
     The Arasan MDIO IP on our chip uses two registers to program
     MDIO.

     data[16:0]
     control
     1   1111   1    00000   00000
     5   4321   0    98765   43210
     -   ----   --   -----   -----
     st  xxxx   op   reg     phy

     st: 1 - start, poll for completion
     op: 1 - read, 0 write


     These are encoded into the serial MDIO protocol as follows

     IEEE MDIO frame
     33 22   22222   22211   11  1111110000000000
     10 98   76543   21098   76  5432109876543210
     -- --   -----   -----   --  ----------------
     ST OP   PHY     REG     TA  DATA[15:0]

     TA and ST are encoded automatically by Arasan IP.


     This device uses 18 bits to specify register addresses.
     These bits are programmed into the device by paging as follows.

     aaaaaaaaa   aaaaaaaa   aa
     111111111   00000000   00
     876543210   98765432   10
     ---------   --------   ------
     page addr   reg addr   ignore

     Since the registers are all 32-bit, the lower two address
     bits are discarded.  The page is written first using the
     following format.  Note PHY is limited to three bits.

     8213 Page program command
     -----------------------------------------------
     33  22  22   222  22211   11  111111 0000000000
     10  98  76   543  21098   76  543210 9876543210
     --  --  --   ---  -----   --  ------ ----------
     ST  OP  CMD  PHY  xxxxx   TA  xxxxxx page addr

     CMD: 11 - page address write
     CMD: 10 - reg access

     The tricky part is the reg access step following page programming
     Since the register format of arasan swaps the order of reg and
     phy, and since our register address spans these two fields, we
     have to swizzle the bits into place.

     8213 Reg read/write command
     ------------------------------------------------
     33  22  22    2222221   1   11  1111110000000000
     10  98  76    5432109   8   76  5432109876543210
     --  --  --    -------   -   --  ----------------
     ST  OP  CMD   reg adr   W   TA  DATA[15:0]

     W: 0 - lower 16 bits, 1: upper 16 bits

     Programming this operation into Arasan requires

     phy = 'b10 << 3 | regAddr[9:7]
     reg = regAddr[6:2]

     mdioCmd = phy | reg << 5 | op | start


 ********************************************************************/
 ////////////////////////////////////////////////////////////////////
 // NOTE - we do not check for valid base in mdio access routines
 // use must ensure device is initialized and valid prior
 // to using MDIO funtions
 ///////////////////////////////////////////////////////////////////

 ////////////////////////////////////////////////////////////////////
 //      Includes
 ////////////////////////////////////////////////////////////////////
 #include "ruby.h"
 #include <common.h>
 #include <malloc.h>
 #include <net.h>
 #include <asm/io.h>
 #include <asm/arch/platform.h>
 #include <asm/arch/arasan_emac_ahb.h>
 #include "ar8237.h"

 ////////////////////////////////////////////////////////////////////
 //      Defines
 ////////////////////////////////////////////////////////////////////
 #define AR8237_MASK_CTL             (0)
 #define AR8237_MASK_CTL_RESET       (0x80000000)
 #define AR8237_MASK_CLEAR_DEF       (0)
 #define AR8237_MODE_CTRL            (0x04)
 #define AR8237_MODE_RGMII_PHY     (0x07600000)
 //#define AR8237_MODE_RGMII_PHY       (0x07402000)
 #define AR8237_PWS_CTRL             (0x10)
 #define AR8237_PWS_CTRL_DEF         (0x40000000)
 #define AR8237_FWCTL_CTRL           (0x0624)
 #define AR8237_FWCTL_CTRL_DEF       (0x007f7f7f)
 #define AR8237_PORT6_CTRL           (0xc)
 #define AR8237_PORT6_CTRL_DEF       (0x01000000)
 #define AR8237_PORT0_CTRL           (0x7c)
 #define AR8237_PORT0_CTRL_DEF       (0x7e)

 #define AR8237_MDIO_START           (1 << 15)
 #define AR8237_MDIO_WRITE           (0 << 10)
 #define AR8237_MDIO_READ            (1 << 10)
 #define AR8237_MDIO_HIGH_WORD       (1 << 0)

 #define AR8237_MDIO_TIMEOUT         (0x1000)
 #define AR8237_MDIO_PAGE            (0x18)
 #define AR8237_MDIO_NORM            (0x10)

 #define AR8237_MIN_PHY_NUM          (0)
 #define AR8237_MAX_PHY_NUM          (4)

 ////////////////////////////////////////////////////////////////////
 //      Types
 ////////////////////////////////////////////////////////////////////

 ////////////////////////////////////////////////////////////////////
 //      Data
 ////////////////////////////////////////////////////////////////////
 static ts8237 g8237Dev;
 extern int mdc_clk_divisor;

 ////////////////////////////////////////////////////////////////////
 //      Functions
 ////////////////////////////////////////////////////////////////////

 inline u32 ar8237_emac_rdreg(int reg)
 {
 	return *(volatile u32 *)(g8237Dev.base + reg);
 }

 inline void ar8237_emac_wrreg(int reg, u32 val)
 {
 	*(volatile u32 *)(g8237Dev.base + reg) = val;
 }

 /*********************************************************************
  Name:      ar8237_mdio_poll
  Purpose:   mdio poll routine for AR8237 device
  Notes:     Checks for mdio operation complete
 *********************************************************************/
 int ar8237_mdio_poll(void)
 {
 	u32 timeout = AR8237_MDIO_TIMEOUT;

 	// check for clear MDIO status
 	while (timeout--) {
 		int status = ar8237_emac_rdreg(EMAC_MAC_MDIO_CTRL);
 		if ((status & AR8237_MDIO_START) == 0) {
 			break;
 		}
 	}
 	if (timeout == 0) {
 		printf("ar8237 mdio timeout\n");
 		return -1;
 	}
 	return 0;
 }

 /*********************************************************************
  Name:      ar8237_mdio_write
  Purpose:   mdio write routine for AR8237 device
  Notes:     This is a partial blocking call since we require
             more than one cycle to complete the write.
             checks for completion first
 *********************************************************************/
 int ar8237_mdio_write(u32 phyAddr, u32 regAddr, u32 data)
 {
 	u32 highAddr = regAddr >> 9;
 	// need to swizzle the bits into arasan's fields which are different
 	u32 rg = (regAddr & 0x3c) >> 1;
 	u32 ph = (regAddr & 0x1c0) >> 6;

 	// check for clear MDIO status
 	if (ar8237_mdio_poll() != 0) {
 		return -1;
 	}

 	ar8237_emac_wrreg(EMAC_MAC_MDIO_DATA, highAddr);
 	ar8237_emac_wrreg(EMAC_MAC_MDIO_CTRL, (phyAddr & 0x1f) |
 			  ((mdc_clk_divisor & MacMdioCtrlClkMask) << MacMdioCtrlClkShift) |
 			  AR8237_MDIO_START | AR8237_MDIO_PAGE);

 	// wait for completion
 	if (ar8237_mdio_poll() != 0) {
 		return -1;
 	}

 	ar8237_emac_wrreg(EMAC_MAC_MDIO_DATA, (data >> 16) & 0xffff);
 	ar8237_emac_wrreg(EMAC_MAC_MDIO_CTRL,
 			  ((mdc_clk_divisor & MacMdioCtrlClkMask) << MacMdioCtrlClkShift) |
 			  ((rg | AR8237_MDIO_HIGH_WORD) << 5) | ph |
 			  AR8237_MDIO_START | AR8237_MDIO_NORM);
 	if (ar8237_mdio_poll() != 0) {
 		return -1;
 	}

 	ar8237_emac_wrreg(EMAC_MAC_MDIO_DATA, data & 0xffff);
 	ar8237_emac_wrreg(EMAC_MAC_MDIO_CTRL,
 			  ((mdc_clk_divisor & MacMdioCtrlClkMask) << MacMdioCtrlClkShift) |
 			  (rg << 5) | ph | AR8237_MDIO_START |
 			  AR8237_MDIO_NORM);
 	if (ar8237_mdio_poll() != 0) {
 		return -1;
 	}

 	// return without waiting for final completion
 	return 0;
 }

 /*********************************************************************
  Name:      ar8237_mdio_read
  Purpose:   mdio read routine for AR8237 device
  Notes:     This is a blocking call since we require
             more than one cycle to complete the write.
             checks for completion first
 *********************************************************************/
 int ar8237_mdio_read(u32 phyAddr, u32 regAddr, u32 * data)
 {
 	u32 highAddr = regAddr >> 9;
 	// need to swizzle the bits into arasan's fields which are different
 	u32 rg = (regAddr & 0x3c) >> 1;
 	u32 ph = (regAddr & 0x1c0) >> 6;

 	if (ar8237_mdio_poll() != 0) {
 		return -1;
 	}

 	ar8237_emac_wrreg(EMAC_MAC_MDIO_DATA, highAddr);
 	ar8237_emac_wrreg(EMAC_MAC_MDIO_CTRL, phyAddr | AR8237_MDIO_START |
 			  ((mdc_clk_divisor & MacMdioCtrlClkMask) << MacMdioCtrlClkShift) |
 			  AR8237_MDIO_PAGE);
 	if (ar8237_mdio_poll() != 0) {
 		return -1;
 	}

 	ar8237_emac_wrreg(EMAC_MAC_MDIO_CTRL, (rg << 5) | AR8237_MDIO_START |
 			  ((mdc_clk_divisor & MacMdioCtrlClkMask) << MacMdioCtrlClkShift) |
 			  AR8237_MDIO_READ | ph | AR8237_MDIO_NORM);
 	if (ar8237_mdio_poll() != 0) {
 		return -1;
 	}

 	*data = ar8237_emac_rdreg(EMAC_MAC_MDIO_DATA);

 	ar8237_emac_wrreg(EMAC_MAC_MDIO_CTRL,
 			  ((mdc_clk_divisor & MacMdioCtrlClkMask) << MacMdioCtrlClkShift) |
 			  ((rg | AR8237_MDIO_HIGH_WORD) << 5) |
 			  AR8237_MDIO_START | AR8237_MDIO_READ | ph |
 			  AR8237_MDIO_NORM);
 	if (ar8237_mdio_poll() != 0) {
 		return -1;
 	}

 	*data = *data | (ar8237_emac_rdreg(EMAC_MAC_MDIO_DATA) << 16);
 	return 0;
 }

 /*********************************************************************
  Name:      ar8237_init
  Purpose:   Check for Atheros 8237 switch, return pointer to device
             if found, NULL otherwise
  Notes:     pass phy addr as -1 to scan for phy
 *********************************************************************/
 u32 ar8237_init(u32 baseAddr, u32 phy_addr)
 {
 	u32 addr;
 	u32 devID;
 	g8237Dev.base = baseAddr;

 	// need to scan?
 	if (phy_addr >=EMAC_PHY_ADDR_SCAN) {
 		addr = AR8237_MIN_PHY_NUM;
 	} else {
 		if (phy_addr >= AR8237_MAX_PHY_NUM) {
 			printf("config error: phy addr out of range\n");
 			return EMAC_PHY_ADDR_SCAN;
 		}
 		addr = phy_addr;
 	}

 	while (addr <  AR8237_MAX_PHY_NUM) {
 		uint32_t reset = AR8237_MASK_CTL_RESET;
 		ar8237_mdio_read(addr, AR8237_MASK_CTL, &devID);
 		if ((devID & 0xff00) == 0x1200) {
 			printf("Detected AR8237 Switch %d - set for RGMII, 1000FD\n",addr);

 			// do a softreset
 			ar8237_mdio_write(phy_addr, AR8237_MODE_CTRL,  AR8237_MODE_RGMII_PHY);

 			// do a clean reset and wait for completion
 			ar8237_mdio_write(phy_addr, AR8237_MASK_CTL, AR8237_MASK_CTL_RESET);
 			while (reset & AR8237_MASK_CTL_RESET) {
 				ar8237_mdio_read(addr, AR8237_MASK_CTL, &reset);
 			}

 			ar8237_mdio_write(phy_addr, AR8237_MASK_CTL, AR8237_MASK_CLEAR_DEF);


 			ar8237_mdio_write(phy_addr, AR8237_PWS_CTRL, AR8237_PWS_CTRL_DEF);
 			ar8237_mdio_write(phy_addr, AR8237_FWCTL_CTRL, AR8237_FWCTL_CTRL_DEF);
 			ar8237_mdio_write(phy_addr, AR8237_PORT6_CTRL, AR8237_PORT6_CTRL_DEF);
 			ar8237_mdio_write(phy_addr, AR8237_PORT0_CTRL, AR8237_PORT0_CTRL_DEF);
 			g8237Dev.phy = addr;

 			//set the register 0xe00000b4 for RGMII Dll control register
 			*(volatile u32 *)(0xe00000b4) = 0x86868f8f;

 			return addr;
 		}
 		if (phy_addr == MAX_PHY_ADDR) {
 			addr++;
 		} else {
 			// not found on passed addr
 			break;
 		}
 	}
 	printf("Error: AR8237 not found\n");
 	return EMAC_PHY_ADDR_SCAN;
 }
	/*
	* board/ums/ar8237.c
	*
	* U-Boot driver for the Atheros 8237 switch.
	*
	* Copyright (c) Quantenna Communications Incorporated 2009.
	* All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*
	*/

	/********************************************************************
	Atheros 8237 MDIO programming details
	The Arasan MDIO IP on our chip uses two registers to program
	MDIO.

	data[16:0]
	control
	1 1111 1 00000 00000
	5 4321 0 98765 43210
	- ---- -- ----- -----
	st xxxx op reg phy

	st: 1 - start, poll for completion
	op: 1 - read, 0 write


	These are encoded into the serial MDIO protocol as follows

	IEEE MDIO frame
	33 22 22222 22211 11 1111110000000000
	10 98 76543 21098 76 5432109876543210
	-- -- ----- ----- -- ----------------
	ST OP PHY REG TA DATA[15:0]

	TA and ST are encoded automatically by Arasan IP.


	This device uses 18 bits to specify register addresses.
	These bits are programmed into the device by paging as follows.

	aaaaaaaaa aaaaaaaa aa
	111111111 00000000 00
	876543210 98765432 10
	--------- -------- ------
	page addr reg addr ignore

	Since the registers are all 32-bit, the lower two address
	bits are discarded. The page is written first using the
	following format. Note PHY is limited to three bits.

	8213 Page program command
	-----------------------------------------------
	33 22 22 222 22211 11 111111 0000000000
	10 98 76 543 21098 76 543210 9876543210
	-- -- -- --- ----- -- ------ ----------
	ST OP CMD PHY xxxxx TA xxxxxx page addr

	CMD: 11 - page address write
	CMD: 10 - reg access

	The tricky part is the reg access step following page programming
	Since the register format of arasan swaps the order of reg and
	phy, and since our register address spans these two fields, we
	have to swizzle the bits into place.

	8213 Reg read/write command
	------------------------------------------------
	33 22 22 2222221 1 11 1111110000000000
	10 98 76 5432109 8 76 5432109876543210
	-- -- -- ------- - -- ----------------
	ST OP CMD reg adr W TA DATA[15:0]

	W: 0 - lower 16 bits, 1: upper 16 bits

	Programming this operation into Arasan requires

	phy = 'b10 << 3 \| regAddr[9:7]
	reg = regAddr[6:2]

	mdioCmd = phy \| reg << 5 \| op \| start


	********************************************************************/
	////////////////////////////////////////////////////////////////////
	// NOTE - we do not check for valid base in mdio access routines
	// use must ensure device is initialized and valid prior
	// to using MDIO funtions
	///////////////////////////////////////////////////////////////////

	////////////////////////////////////////////////////////////////////
	// Includes
	////////////////////////////////////////////////////////////////////
	#include "ruby.h"
	#include <common.h>
	#include <malloc.h>
	#include <net.h>
	#include <asm/io.h>
	#include <asm/arch/platform.h>
	#include <asm/arch/arasan_emac_ahb.h>
	#include "ar8237.h"

	////////////////////////////////////////////////////////////////////
	// Defines
	////////////////////////////////////////////////////////////////////
	#define AR8237_MASK_CTL (0)
	#define AR8237_MASK_CTL_RESET (0x80000000)
	#define AR8237_MASK_CLEAR_DEF (0)
	#define AR8237_MODE_CTRL (0x04)
	#define AR8237_MODE_RGMII_PHY (0x07600000)
	//#define AR8237_MODE_RGMII_PHY (0x07402000)
	#define AR8237_PWS_CTRL (0x10)
	#define AR8237_PWS_CTRL_DEF (0x40000000)
	#define AR8237_FWCTL_CTRL (0x0624)
	#define AR8237_FWCTL_CTRL_DEF (0x007f7f7f)
	#define AR8237_PORT6_CTRL (0xc)
	#define AR8237_PORT6_CTRL_DEF (0x01000000)
	#define AR8237_PORT0_CTRL (0x7c)
	#define AR8237_PORT0_CTRL_DEF (0x7e)

	#define AR8237_MDIO_START (1 << 15)
	#define AR8237_MDIO_WRITE (0 << 10)
	#define AR8237_MDIO_READ (1 << 10)
	#define AR8237_MDIO_HIGH_WORD (1 << 0)

	#define AR8237_MDIO_TIMEOUT (0x1000)
	#define AR8237_MDIO_PAGE (0x18)
	#define AR8237_MDIO_NORM (0x10)

	#define AR8237_MIN_PHY_NUM (0)
	#define AR8237_MAX_PHY_NUM (4)

	////////////////////////////////////////////////////////////////////
	// Types
	////////////////////////////////////////////////////////////////////

	////////////////////////////////////////////////////////////////////
	// Data
	////////////////////////////////////////////////////////////////////
	static ts8237 g8237Dev;
	extern int mdc_clk_divisor;

	////////////////////////////////////////////////////////////////////
	// Functions
	////////////////////////////////////////////////////////////////////

	inline u32 ar8237_emac_rdreg(int reg)
	{
	return (volatile u32 )(g8237Dev.base + reg);
	}

	inline void ar8237_emac_wrreg(int reg, u32 val)
	{
	(volatile u32 )(g8237Dev.base + reg) = val;
	}

	/*********************************************************************
	Name: ar8237_mdio_poll
	Purpose: mdio poll routine for AR8237 device
	Notes: Checks for mdio operation complete
	*********************************************************************/
	int ar8237_mdio_poll(void)
	{
	u32 timeout = AR8237_MDIO_TIMEOUT;

	// check for clear MDIO status
	while (timeout--) {
	int status = ar8237_emac_rdreg(EMAC_MAC_MDIO_CTRL);
	if ((status & AR8237_MDIO_START) == 0) {
	break;
	}
	}
	if (timeout == 0) {
	printf("ar8237 mdio timeout\n");
	return -1;
	}
	return 0;
	}

	/*********************************************************************
	Name: ar8237_mdio_write
	Purpose: mdio write routine for AR8237 device
	Notes: This is a partial blocking call since we require
	more than one cycle to complete the write.
	checks for completion first
	*********************************************************************/
	int ar8237_mdio_write(u32 phyAddr, u32 regAddr, u32 data)
	{
	u32 highAddr = regAddr >> 9;
	// need to swizzle the bits into arasan's fields which are different
	u32 rg = (regAddr & 0x3c) >> 1;
	u32 ph = (regAddr & 0x1c0) >> 6;

	// check for clear MDIO status
	if (ar8237_mdio_poll() != 0) {
	return -1;
	}

	ar8237_emac_wrreg(EMAC_MAC_MDIO_DATA, highAddr);
	ar8237_emac_wrreg(EMAC_MAC_MDIO_CTRL, (phyAddr & 0x1f) \|
	((mdc_clk_divisor & MacMdioCtrlClkMask) << MacMdioCtrlClkShift) \|
	AR8237_MDIO_START \| AR8237_MDIO_PAGE);

	// wait for completion
	if (ar8237_mdio_poll() != 0) {
	return -1;
	}

	ar8237_emac_wrreg(EMAC_MAC_MDIO_DATA, (data >> 16) & 0xffff);
	ar8237_emac_wrreg(EMAC_MAC_MDIO_CTRL,
	((mdc_clk_divisor & MacMdioCtrlClkMask) << MacMdioCtrlClkShift) \|
	((rg \| AR8237_MDIO_HIGH_WORD) << 5) \| ph \|
	AR8237_MDIO_START \| AR8237_MDIO_NORM);
	if (ar8237_mdio_poll() != 0) {
	return -1;
	}

	ar8237_emac_wrreg(EMAC_MAC_MDIO_DATA, data & 0xffff);
	ar8237_emac_wrreg(EMAC_MAC_MDIO_CTRL,
	((mdc_clk_divisor & MacMdioCtrlClkMask) << MacMdioCtrlClkShift) \|
	(rg << 5) \| ph \| AR8237_MDIO_START \|
	AR8237_MDIO_NORM);
	if (ar8237_mdio_poll() != 0) {
	return -1;
	}

	// return without waiting for final completion
	return 0;
	}

	/*********************************************************************
	Name: ar8237_mdio_read
	Purpose: mdio read routine for AR8237 device
	Notes: This is a blocking call since we require
	more than one cycle to complete the write.
	checks for completion first
	*********************************************************************/
	int ar8237_mdio_read(u32 phyAddr, u32 regAddr, u32 * data)
	{
	u32 highAddr = regAddr >> 9;
	// need to swizzle the bits into arasan's fields which are different
	u32 rg = (regAddr & 0x3c) >> 1;
	u32 ph = (regAddr & 0x1c0) >> 6;

	if (ar8237_mdio_poll() != 0) {
	return -1;
	}

	ar8237_emac_wrreg(EMAC_MAC_MDIO_DATA, highAddr);
	ar8237_emac_wrreg(EMAC_MAC_MDIO_CTRL, phyAddr \| AR8237_MDIO_START \|
	((mdc_clk_divisor & MacMdioCtrlClkMask) << MacMdioCtrlClkShift) \|
	AR8237_MDIO_PAGE);
	if (ar8237_mdio_poll() != 0) {
	return -1;
	}

	ar8237_emac_wrreg(EMAC_MAC_MDIO_CTRL, (rg << 5) \| AR8237_MDIO_START \|
	((mdc_clk_divisor & MacMdioCtrlClkMask) << MacMdioCtrlClkShift) \|
	AR8237_MDIO_READ \| ph \| AR8237_MDIO_NORM);
	if (ar8237_mdio_poll() != 0) {
	return -1;
	}

	*data = ar8237_emac_rdreg(EMAC_MAC_MDIO_DATA);

	ar8237_emac_wrreg(EMAC_MAC_MDIO_CTRL,
	((mdc_clk_divisor & MacMdioCtrlClkMask) << MacMdioCtrlClkShift) \|
	((rg \| AR8237_MDIO_HIGH_WORD) << 5) \|
	AR8237_MDIO_START \| AR8237_MDIO_READ \| ph \|
	AR8237_MDIO_NORM);
	if (ar8237_mdio_poll() != 0) {
	return -1;
	}

	data = data \| (ar8237_emac_rdreg(EMAC_MAC_MDIO_DATA) << 16);
	return 0;
	}

	/*********************************************************************
	Name: ar8237_init
	Purpose: Check for Atheros 8237 switch, return pointer to device
	if found, NULL otherwise
	Notes: pass phy addr as -1 to scan for phy
	*********************************************************************/
	u32 ar8237_init(u32 baseAddr, u32 phy_addr)
	{
	u32 addr;
	u32 devID;
	g8237Dev.base = baseAddr;

	// need to scan?
	if (phy_addr >=EMAC_PHY_ADDR_SCAN) {
	addr = AR8237_MIN_PHY_NUM;
	} else {
	if (phy_addr >= AR8237_MAX_PHY_NUM) {
	printf("config error: phy addr out of range\n");
	return EMAC_PHY_ADDR_SCAN;
	}
	addr = phy_addr;
	}

	while (addr < AR8237_MAX_PHY_NUM) {
	uint32_t reset = AR8237_MASK_CTL_RESET;
	ar8237_mdio_read(addr, AR8237_MASK_CTL, &devID);
	if ((devID & 0xff00) == 0x1200) {
	printf("Detected AR8237 Switch %d - set for RGMII, 1000FD\n",addr);

	// do a softreset
	ar8237_mdio_write(phy_addr, AR8237_MODE_CTRL, AR8237_MODE_RGMII_PHY);

	// do a clean reset and wait for completion
	ar8237_mdio_write(phy_addr, AR8237_MASK_CTL, AR8237_MASK_CTL_RESET);
	while (reset & AR8237_MASK_CTL_RESET) {
	ar8237_mdio_read(addr, AR8237_MASK_CTL, &reset);
	}

	ar8237_mdio_write(phy_addr, AR8237_MASK_CTL, AR8237_MASK_CLEAR_DEF);


	ar8237_mdio_write(phy_addr, AR8237_PWS_CTRL, AR8237_PWS_CTRL_DEF);
	ar8237_mdio_write(phy_addr, AR8237_FWCTL_CTRL, AR8237_FWCTL_CTRL_DEF);
	ar8237_mdio_write(phy_addr, AR8237_PORT6_CTRL, AR8237_PORT6_CTRL_DEF);
	ar8237_mdio_write(phy_addr, AR8237_PORT0_CTRL, AR8237_PORT0_CTRL_DEF);
	g8237Dev.phy = addr;

	//set the register 0xe00000b4 for RGMII Dll control register
	(volatile u32 )(0xe00000b4) = 0x86868f8f;

	return addr;
	}
	if (phy_addr == MAX_PHY_ADDR) {
	addr++;
	} else {
	// not found on passed addr
	break;
	}
	}
	printf("Error: AR8237 not found\n");
	return EMAC_PHY_ADDR_SCAN;
	}