cpu/mpc8220/i2c.c - platform/external/u-boot - Gitiles

 /*
  * (C) Copyright 2004, Freescale, Inc
  * TsiChung Liew, Tsi-Chung.Liew@freescale.com.
  *
  * See file CREDITS for list of people who contributed to this
  * project.
  *
  * 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
  */

 #include <common.h>

 #ifdef CONFIG_HARD_I2C

 #include <mpc8220.h>
 #include <i2c.h>

 typedef struct mpc8220_i2c {
 	volatile u32 adr;	/* I2Cn + 0x00 */
 	volatile u32 fdr;	/* I2Cn + 0x04 */
 	volatile u32 cr;	/* I2Cn + 0x08 */
 	volatile u32 sr;	/* I2Cn + 0x0C */
 	volatile u32 dr;	/* I2Cn + 0x10 */
 } i2c_t;

 /* I2Cn control register bits */
 #define I2C_EN      0x80
 #define I2C_IEN     0x40
 #define I2C_STA     0x20
 #define I2C_TX      0x10
 #define I2C_TXAK    0x08
 #define I2C_RSTA    0x04
 #define I2C_INIT_MASK   (I2C_EN | I2C_STA | I2C_TX | I2C_RSTA)

 /* I2Cn status register bits */
 #define I2C_CF      0x80
 #define I2C_AAS     0x40
 #define I2C_BB      0x20
 #define I2C_AL      0x10
 #define I2C_SRW     0x04
 #define I2C_IF      0x02
 #define I2C_RXAK    0x01

 #define I2C_TIMEOUT 100
 #define I2C_RETRIES 1

 struct mpc8220_i2c_tap {
 	int scl2tap;
 	int tap2tap;
 };

 static int mpc_reg_in (volatile u32 * reg);
 static void mpc_reg_out (volatile u32 * reg, int val, int mask);
 static int wait_for_bb (void);
 static int wait_for_pin (int *status);
 static int do_address (uchar chip, char rdwr_flag);
 static int send_bytes (uchar chip, char *buf, int len);
 static int receive_bytes (uchar chip, char *buf, int len);
 static int mpc_get_fdr (int);

 static int mpc_reg_in (volatile u32 * reg)
 {
 	int ret;
 	ret = *reg >> 24;
 	__asm__ __volatile__ ("eieio");
 	return ret;
 }

 static void mpc_reg_out (volatile u32 * reg, int val, int mask)
 {
 	int tmp;

 	if (!mask) {
 		*reg = val << 24;
 	} else {
 		tmp = mpc_reg_in (reg);
 		*reg = ((tmp & ~mask) | (val & mask)) << 24;
 	}
 	__asm__ __volatile__ ("eieio");

 	return;
 }

 static int wait_for_bb (void)
 {
 	i2c_t *regs = (i2c_t *) MMAP_I2C;
 	int timeout = I2C_TIMEOUT;
 	int status;

 	status = mpc_reg_in (&regs->sr);

 	while (timeout-- && (status & I2C_BB)) {
 #if 1
 		volatile int temp;

 		mpc_reg_out (&regs->cr, I2C_STA, I2C_STA);
 		temp = mpc_reg_in (&regs->dr);
 		mpc_reg_out (&regs->cr, 0, I2C_STA);
 		mpc_reg_out (&regs->cr, 0, 0);
 		mpc_reg_out (&regs->cr, I2C_EN, 0);
 #endif
 		udelay (1000);
 		status = mpc_reg_in (&regs->sr);
 	}

 	return (status & I2C_BB);
 }

 static int wait_for_pin (int *status)
 {
 	i2c_t *regs = (i2c_t *) MMAP_I2C;
 	int timeout = I2C_TIMEOUT;

 	*status = mpc_reg_in (&regs->sr);

 	while (timeout-- && !(*status & I2C_IF)) {
 		udelay (1000);
 		*status = mpc_reg_in (&regs->sr);
 	}

 	if (!(*status & I2C_IF)) {
 		return -1;
 	}

 	mpc_reg_out (&regs->sr, 0, I2C_IF);
 	return 0;
 }

 static int do_address (uchar chip, char rdwr_flag)
 {
 	i2c_t *regs = (i2c_t *) MMAP_I2C;
 	int status;

 	chip <<= 1;

 	if (rdwr_flag)
 		chip |= 1;

 	mpc_reg_out (&regs->cr, I2C_TX, I2C_TX);
 	mpc_reg_out (&regs->dr, chip, 0);

 	if (wait_for_pin (&status))
 		return -2;
 	if (status & I2C_RXAK)
 		return -3;
 	return 0;
 }

 static int send_bytes (uchar chip, char *buf, int len)
 {
 	i2c_t *regs = (i2c_t *) MMAP_I2C;
 	int wrcount;
 	int status;

 	for (wrcount = 0; wrcount < len; ++wrcount) {

 		mpc_reg_out (&regs->dr, buf[wrcount], 0);

 		if (wait_for_pin (&status))
 			break;

 		if (status & I2C_RXAK)
 			break;

 	}

 	return !(wrcount == len);
 	return 0;
 }

 static int receive_bytes (uchar chip, char *buf, int len)
 {
 	i2c_t *regs = (i2c_t *) MMAP_I2C;
 	int dummy = 1;
 	int rdcount = 0;
 	int status;
 	int i;

 	mpc_reg_out (&regs->cr, 0, I2C_TX);

 	for (i = 0; i < len; ++i) {
 		buf[rdcount] = mpc_reg_in (&regs->dr);

 		if (dummy)
 			dummy = 0;
 		else
 			rdcount++;

 		if (wait_for_pin (&status))
 			return -4;
 	}

 	mpc_reg_out (&regs->cr, I2C_TXAK, I2C_TXAK);
 	buf[rdcount++] = mpc_reg_in (&regs->dr);

 	if (wait_for_pin (&status))
 		return -5;

 	mpc_reg_out (&regs->cr, 0, I2C_TXAK);
 	return 0;
 }

 /**************** I2C API ****************/

 void i2c_init (int speed, int saddr)
 {
 	i2c_t *regs = (i2c_t *) MMAP_I2C;

 	mpc_reg_out (&regs->cr, 0, 0);
 	mpc_reg_out (&regs->adr, saddr << 1, 0);

 	/* Set clock
 	 */
 	mpc_reg_out (&regs->fdr, mpc_get_fdr (speed), 0);

 	/* Enable module
 	 */
 	mpc_reg_out (&regs->cr, I2C_EN, I2C_INIT_MASK);
 	mpc_reg_out (&regs->sr, 0, I2C_IF);
 	return;
 }

 static int mpc_get_fdr (int speed)
 {
 	DECLARE_GLOBAL_DATA_PTR;
 	static int fdr = -1;

 	if (fdr == -1) {
 		ulong best_speed = 0;
 		ulong divider;
 		ulong ipb, scl;
 		ulong bestmatch = 0xffffffffUL;
 		int best_i = 0, best_j = 0, i, j;
 		int SCL_Tap[] = { 9, 10, 12, 15, 5, 6, 7, 8 };
 		struct mpc8220_i2c_tap scltap[] = {
 			{4, 1},
 			{4, 2},
 			{6, 4},
 			{6, 8},
 			{14, 16},
 			{30, 32},
 			{62, 64},
 			{126, 128}
 		};

 		ipb = gd->bus_clk;
 		for (i = 7; i >= 0; i--) {
 			for (j = 7; j >= 0; j--) {
 				scl = 2 * (scltap[j].scl2tap +
 					   (SCL_Tap[i] -
 					    1) * scltap[j].tap2tap + 2);
 				if (ipb <= speed * scl) {
 					if ((speed * scl - ipb) < bestmatch) {
 						bestmatch = speed * scl - ipb;
 						best_i = i;
 						best_j = j;
 						best_speed = ipb / scl;
 					}
 				}
 			}
 		}
 		divider = (best_i & 3) | ((best_i & 4) << 3) | (best_j << 2);
 		if (gd->flags & GD_FLG_RELOC) {
 			fdr = divider;
 		} else {
 			printf ("%ld kHz, ", best_speed / 1000);
 			return divider;
 		}
 	}

 	return fdr;
 }

 int i2c_probe (uchar chip)
 {
 	i2c_t *regs = (i2c_t *) MMAP_I2C;
 	int i;

 	for (i = 0; i < I2C_RETRIES; i++) {
 		mpc_reg_out (&regs->cr, I2C_STA, I2C_STA);

 		if (!do_address (chip, 0)) {
 			mpc_reg_out (&regs->cr, 0, I2C_STA);
 			break;
 		}

 		mpc_reg_out (&regs->cr, 0, I2C_STA);
 		udelay (50);
 	}

 	return (i == I2C_RETRIES);
 }

 int i2c_read (uchar chip, uint addr, int alen, uchar * buf, int len)
 {
 	uchar xaddr[4];
 	i2c_t *regs = (i2c_t *) MMAP_I2C;
 	int ret = -1;

 	xaddr[0] = (addr >> 24) & 0xFF;
 	xaddr[1] = (addr >> 16) & 0xFF;
 	xaddr[2] = (addr >> 8) & 0xFF;
 	xaddr[3] = addr & 0xFF;

 	if (wait_for_bb ()) {
 		printf ("i2c_read: bus is busy\n");
 		goto Done;
 	}

 	mpc_reg_out (&regs->cr, I2C_STA, I2C_STA);
 	if (do_address (chip, 0)) {
 		printf ("i2c_read: failed to address chip\n");
 		goto Done;
 	}

 	if (send_bytes (chip, (char *)&xaddr[4 - alen], alen)) {
 		printf ("i2c_read: send_bytes failed\n");
 		goto Done;
 	}

 	mpc_reg_out (&regs->cr, I2C_RSTA, I2C_RSTA);
 	if (do_address (chip, 1)) {
 		printf ("i2c_read: failed to address chip\n");
 		goto Done;
 	}

 	if (receive_bytes (chip, (char *)buf, len)) {
 		printf ("i2c_read: receive_bytes failed\n");
 		goto Done;
 	}

 	ret = 0;
       Done:
 	mpc_reg_out (&regs->cr, 0, I2C_STA);
 	return ret;
 }

 int i2c_write (uchar chip, uint addr, int alen, uchar * buf, int len)
 {
 	uchar xaddr[4];
 	i2c_t *regs = (i2c_t *) MMAP_I2C;
 	int ret = -1;

 	xaddr[0] = (addr >> 24) & 0xFF;
 	xaddr[1] = (addr >> 16) & 0xFF;
 	xaddr[2] = (addr >> 8) & 0xFF;
 	xaddr[3] = addr & 0xFF;

 	if (wait_for_bb ()) {
 		printf ("i2c_write: bus is busy\n");
 		goto Done;
 	}

 	mpc_reg_out (&regs->cr, I2C_STA, I2C_STA);
 	if (do_address (chip, 0)) {
 		printf ("i2c_write: failed to address chip\n");
 		goto Done;
 	}

 	if (send_bytes (chip, (char *)&xaddr[4 - alen], alen)) {
 		printf ("i2c_write: send_bytes failed\n");
 		goto Done;
 	}

 	if (send_bytes (chip, (char *)buf, len)) {
 		printf ("i2c_write: send_bytes failed\n");
 		goto Done;
 	}

 	ret = 0;
       Done:
 	mpc_reg_out (&regs->cr, 0, I2C_STA);
 	return ret;
 }

 uchar i2c_reg_read (uchar chip, uchar reg)
 {
 	uchar buf;

 	i2c_read (chip, reg, 1, &buf, 1);

 	return buf;
 }

 void i2c_reg_write (uchar chip, uchar reg, uchar val)
 {
 	i2c_write (chip, reg, 1, &val, 1);

 	return;
 }

 #endif /* CONFIG_HARD_I2C */
	/*
	* (C) Copyright 2004, Freescale, Inc
	* TsiChung Liew, Tsi-Chung.Liew@freescale.com.
	*
	* See file CREDITS for list of people who contributed to this
	* project.
	*
	* 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
	*/

	#include <common.h>

	#ifdef CONFIG_HARD_I2C

	#include <mpc8220.h>
	#include <i2c.h>

	typedef struct mpc8220_i2c {
	volatile u32 adr; /* I2Cn + 0x00 */
	volatile u32 fdr; /* I2Cn + 0x04 */
	volatile u32 cr; /* I2Cn + 0x08 */
	volatile u32 sr; /* I2Cn + 0x0C */
	volatile u32 dr; /* I2Cn + 0x10 */
	} i2c_t;

	/* I2Cn control register bits */
	#define I2C_EN 0x80
	#define I2C_IEN 0x40
	#define I2C_STA 0x20
	#define I2C_TX 0x10
	#define I2C_TXAK 0x08
	#define I2C_RSTA 0x04
	#define I2C_INIT_MASK (I2C_EN \| I2C_STA \| I2C_TX \| I2C_RSTA)

	/* I2Cn status register bits */
	#define I2C_CF 0x80
	#define I2C_AAS 0x40
	#define I2C_BB 0x20
	#define I2C_AL 0x10
	#define I2C_SRW 0x04
	#define I2C_IF 0x02
	#define I2C_RXAK 0x01

	#define I2C_TIMEOUT 100
	#define I2C_RETRIES 1

	struct mpc8220_i2c_tap {
	int scl2tap;
	int tap2tap;
	};

	static int mpc_reg_in (volatile u32 * reg);
	static void mpc_reg_out (volatile u32 * reg, int val, int mask);
	static int wait_for_bb (void);
	static int wait_for_pin (int *status);
	static int do_address (uchar chip, char rdwr_flag);
	static int send_bytes (uchar chip, char *buf, int len);
	static int receive_bytes (uchar chip, char *buf, int len);
	static int mpc_get_fdr (int);

	static int mpc_reg_in (volatile u32 * reg)
	{
	int ret;
	ret = *reg >> 24;
	__asm__ __volatile__ ("eieio");
	return ret;
	}

	static void mpc_reg_out (volatile u32 * reg, int val, int mask)
	{
	int tmp;

	if (!mask) {
	*reg = val << 24;
	} else {
	tmp = mpc_reg_in (reg);
	*reg = ((tmp & ~mask) \| (val & mask)) << 24;
	}
	__asm__ __volatile__ ("eieio");

	return;
	}

	static int wait_for_bb (void)
	{
	i2c_t regs = (i2c_t ) MMAP_I2C;
	int timeout = I2C_TIMEOUT;
	int status;

	status = mpc_reg_in (&regs->sr);

	while (timeout-- && (status & I2C_BB)) {
	#if 1
	volatile int temp;

	mpc_reg_out (&regs->cr, I2C_STA, I2C_STA);
	temp = mpc_reg_in (&regs->dr);
	mpc_reg_out (&regs->cr, 0, I2C_STA);
	mpc_reg_out (&regs->cr, 0, 0);
	mpc_reg_out (&regs->cr, I2C_EN, 0);
	#endif
	udelay (1000);
	status = mpc_reg_in (&regs->sr);
	}

	return (status & I2C_BB);
	}

	static int wait_for_pin (int *status)
	{
	i2c_t regs = (i2c_t ) MMAP_I2C;
	int timeout = I2C_TIMEOUT;

	*status = mpc_reg_in (&regs->sr);

	while (timeout-- && !(*status & I2C_IF)) {
	udelay (1000);
	*status = mpc_reg_in (&regs->sr);
	}

	if (!(*status & I2C_IF)) {
	return -1;
	}

	mpc_reg_out (&regs->sr, 0, I2C_IF);
	return 0;
	}

	static int do_address (uchar chip, char rdwr_flag)
	{
	i2c_t regs = (i2c_t ) MMAP_I2C;
	int status;

	chip <<= 1;

	if (rdwr_flag)
	chip \|= 1;

	mpc_reg_out (&regs->cr, I2C_TX, I2C_TX);
	mpc_reg_out (&regs->dr, chip, 0);

	if (wait_for_pin (&status))
	return -2;
	if (status & I2C_RXAK)
	return -3;
	return 0;
	}

	static int send_bytes (uchar chip, char *buf, int len)
	{
	i2c_t regs = (i2c_t ) MMAP_I2C;
	int wrcount;
	int status;

	for (wrcount = 0; wrcount < len; ++wrcount) {

	mpc_reg_out (&regs->dr, buf[wrcount], 0);

	if (wait_for_pin (&status))
	break;

	if (status & I2C_RXAK)
	break;

	}

	return !(wrcount == len);
	return 0;
	}

	static int receive_bytes (uchar chip, char *buf, int len)
	{
	i2c_t regs = (i2c_t ) MMAP_I2C;
	int dummy = 1;
	int rdcount = 0;
	int status;
	int i;

	mpc_reg_out (&regs->cr, 0, I2C_TX);

	for (i = 0; i < len; ++i) {
	buf[rdcount] = mpc_reg_in (&regs->dr);

	if (dummy)
	dummy = 0;
	else
	rdcount++;

	if (wait_for_pin (&status))
	return -4;
	}

	mpc_reg_out (&regs->cr, I2C_TXAK, I2C_TXAK);
	buf[rdcount++] = mpc_reg_in (&regs->dr);

	if (wait_for_pin (&status))
	return -5;

	mpc_reg_out (&regs->cr, 0, I2C_TXAK);
	return 0;
	}

	/************** I2C API **************/

	void i2c_init (int speed, int saddr)
	{
	i2c_t regs = (i2c_t ) MMAP_I2C;

	mpc_reg_out (&regs->cr, 0, 0);
	mpc_reg_out (&regs->adr, saddr << 1, 0);

	/* Set clock
	*/
	mpc_reg_out (&regs->fdr, mpc_get_fdr (speed), 0);

	/* Enable module
	*/
	mpc_reg_out (&regs->cr, I2C_EN, I2C_INIT_MASK);
	mpc_reg_out (&regs->sr, 0, I2C_IF);
	return;
	}

	static int mpc_get_fdr (int speed)
	{
	DECLARE_GLOBAL_DATA_PTR;
	static int fdr = -1;

	if (fdr == -1) {
	ulong best_speed = 0;
	ulong divider;
	ulong ipb, scl;
	ulong bestmatch = 0xffffffffUL;
	int best_i = 0, best_j = 0, i, j;
	int SCL_Tap[] = { 9, 10, 12, 15, 5, 6, 7, 8 };
	struct mpc8220_i2c_tap scltap[] = {
	{4, 1},
	{4, 2},
	{6, 4},
	{6, 8},
	{14, 16},
	{30, 32},
	{62, 64},
	{126, 128}
	};

	ipb = gd->bus_clk;
	for (i = 7; i >= 0; i--) {
	for (j = 7; j >= 0; j--) {
	scl = 2 * (scltap[j].scl2tap +
	(SCL_Tap[i] -
	1) * scltap[j].tap2tap + 2);
	if (ipb <= speed * scl) {
	if ((speed * scl - ipb) < bestmatch) {
	bestmatch = speed * scl - ipb;
	best_i = i;
	best_j = j;
	best_speed = ipb / scl;
	}
	}
	}
	}
	divider = (best_i & 3) \| ((best_i & 4) << 3) \| (best_j << 2);
	if (gd->flags & GD_FLG_RELOC) {
	fdr = divider;
	} else {
	printf ("%ld kHz, ", best_speed / 1000);
	return divider;
	}
	}

	return fdr;
	}

	int i2c_probe (uchar chip)
	{
	i2c_t regs = (i2c_t ) MMAP_I2C;
	int i;

	for (i = 0; i < I2C_RETRIES; i++) {
	mpc_reg_out (&regs->cr, I2C_STA, I2C_STA);

	if (!do_address (chip, 0)) {
	mpc_reg_out (&regs->cr, 0, I2C_STA);
	break;
	}

	mpc_reg_out (&regs->cr, 0, I2C_STA);
	udelay (50);
	}

	return (i == I2C_RETRIES);
	}

	int i2c_read (uchar chip, uint addr, int alen, uchar * buf, int len)
	{
	uchar xaddr[4];
	i2c_t regs = (i2c_t ) MMAP_I2C;
	int ret = -1;

	xaddr[0] = (addr >> 24) & 0xFF;
	xaddr[1] = (addr >> 16) & 0xFF;
	xaddr[2] = (addr >> 8) & 0xFF;
	xaddr[3] = addr & 0xFF;

	if (wait_for_bb ()) {
	printf ("i2c_read: bus is busy\n");
	goto Done;
	}

	mpc_reg_out (&regs->cr, I2C_STA, I2C_STA);
	if (do_address (chip, 0)) {
	printf ("i2c_read: failed to address chip\n");
	goto Done;
	}

	if (send_bytes (chip, (char *)&xaddr[4 - alen], alen)) {
	printf ("i2c_read: send_bytes failed\n");
	goto Done;
	}

	mpc_reg_out (&regs->cr, I2C_RSTA, I2C_RSTA);
	if (do_address (chip, 1)) {
	printf ("i2c_read: failed to address chip\n");
	goto Done;
	}

	if (receive_bytes (chip, (char *)buf, len)) {
	printf ("i2c_read: receive_bytes failed\n");
	goto Done;
	}

	ret = 0;
	Done:
	mpc_reg_out (&regs->cr, 0, I2C_STA);
	return ret;
	}

	int i2c_write (uchar chip, uint addr, int alen, uchar * buf, int len)
	{
	uchar xaddr[4];
	i2c_t regs = (i2c_t ) MMAP_I2C;
	int ret = -1;

	xaddr[0] = (addr >> 24) & 0xFF;
	xaddr[1] = (addr >> 16) & 0xFF;
	xaddr[2] = (addr >> 8) & 0xFF;
	xaddr[3] = addr & 0xFF;

	if (wait_for_bb ()) {
	printf ("i2c_write: bus is busy\n");
	goto Done;
	}

	mpc_reg_out (&regs->cr, I2C_STA, I2C_STA);
	if (do_address (chip, 0)) {
	printf ("i2c_write: failed to address chip\n");
	goto Done;
	}

	if (send_bytes (chip, (char *)&xaddr[4 - alen], alen)) {
	printf ("i2c_write: send_bytes failed\n");
	goto Done;
	}

	if (send_bytes (chip, (char *)buf, len)) {
	printf ("i2c_write: send_bytes failed\n");
	goto Done;
	}

	ret = 0;
	Done:
	mpc_reg_out (&regs->cr, 0, I2C_STA);
	return ret;
	}

	uchar i2c_reg_read (uchar chip, uchar reg)
	{
	uchar buf;

	i2c_read (chip, reg, 1, &buf, 1);

	return buf;
	}

	void i2c_reg_write (uchar chip, uchar reg, uchar val)
	{
	i2c_write (chip, reg, 1, &val, 1);

	return;
	}

	#endif /* CONFIG_HARD_I2C */