2 * (C) Copyright 2004, Freescale, Inc
3 * TsiChung Liew, Tsi-Chung.Liew@freescale.com.
5 * See file CREDITS for list of people who contributed to this
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of
11 * the License, or (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
26 DECLARE_GLOBAL_DATA_PTR;
28 #ifdef CONFIG_HARD_I2C
33 typedef struct mpc8220_i2c {
34 volatile u32 adr; /* I2Cn + 0x00 */
35 volatile u32 fdr; /* I2Cn + 0x04 */
36 volatile u32 cr; /* I2Cn + 0x08 */
37 volatile u32 sr; /* I2Cn + 0x0C */
38 volatile u32 dr; /* I2Cn + 0x10 */
41 /* I2Cn control register bits */
48 #define I2C_INIT_MASK (I2C_EN | I2C_STA | I2C_TX | I2C_RSTA)
50 /* I2Cn status register bits */
59 #define I2C_TIMEOUT 100
62 struct mpc8220_i2c_tap {
67 static int mpc_reg_in (volatile u32 * reg);
68 static void mpc_reg_out (volatile u32 * reg, int val, int mask);
69 static int wait_for_bb (void);
70 static int wait_for_pin (int *status);
71 static int do_address (uchar chip, char rdwr_flag);
72 static int send_bytes (uchar chip, char *buf, int len);
73 static int receive_bytes (uchar chip, char *buf, int len);
74 static int mpc_get_fdr (int);
76 static int mpc_reg_in (volatile u32 * reg)
80 __asm__ __volatile__ ("eieio");
84 static void mpc_reg_out (volatile u32 * reg, int val, int mask)
91 tmp = mpc_reg_in (reg);
92 *reg = ((tmp & ~mask) | (val & mask)) << 24;
94 __asm__ __volatile__ ("eieio");
99 static int wait_for_bb (void)
101 i2c_t *regs = (i2c_t *) MMAP_I2C;
102 int timeout = I2C_TIMEOUT;
105 status = mpc_reg_in (®s->sr);
107 while (timeout-- && (status & I2C_BB)) {
109 mpc_reg_out (®s->cr, I2C_STA, I2C_STA);
110 (void)mpc_reg_in (®s->dr);
111 mpc_reg_out (®s->cr, 0, I2C_STA);
112 mpc_reg_out (®s->cr, 0, 0);
113 mpc_reg_out (®s->cr, I2C_EN, 0);
116 status = mpc_reg_in (®s->sr);
119 return (status & I2C_BB);
122 static int wait_for_pin (int *status)
124 i2c_t *regs = (i2c_t *) MMAP_I2C;
125 int timeout = I2C_TIMEOUT;
127 *status = mpc_reg_in (®s->sr);
129 while (timeout-- && !(*status & I2C_IF)) {
131 *status = mpc_reg_in (®s->sr);
134 if (!(*status & I2C_IF)) {
138 mpc_reg_out (®s->sr, 0, I2C_IF);
142 static int do_address (uchar chip, char rdwr_flag)
144 i2c_t *regs = (i2c_t *) MMAP_I2C;
152 mpc_reg_out (®s->cr, I2C_TX, I2C_TX);
153 mpc_reg_out (®s->dr, chip, 0);
155 if (wait_for_pin (&status))
157 if (status & I2C_RXAK)
162 static int send_bytes (uchar chip, char *buf, int len)
164 i2c_t *regs = (i2c_t *) MMAP_I2C;
168 for (wrcount = 0; wrcount < len; ++wrcount) {
170 mpc_reg_out (®s->dr, buf[wrcount], 0);
172 if (wait_for_pin (&status))
175 if (status & I2C_RXAK)
180 return !(wrcount == len);
184 static int receive_bytes (uchar chip, char *buf, int len)
186 i2c_t *regs = (i2c_t *) MMAP_I2C;
192 mpc_reg_out (®s->cr, 0, I2C_TX);
194 for (i = 0; i < len; ++i) {
195 buf[rdcount] = mpc_reg_in (®s->dr);
202 if (wait_for_pin (&status))
206 mpc_reg_out (®s->cr, I2C_TXAK, I2C_TXAK);
207 buf[rdcount++] = mpc_reg_in (®s->dr);
209 if (wait_for_pin (&status))
212 mpc_reg_out (®s->cr, 0, I2C_TXAK);
216 /**************** I2C API ****************/
218 void i2c_init (int speed, int saddr)
220 i2c_t *regs = (i2c_t *) MMAP_I2C;
222 mpc_reg_out (®s->cr, 0, 0);
223 mpc_reg_out (®s->adr, saddr << 1, 0);
227 mpc_reg_out (®s->fdr, mpc_get_fdr (speed), 0);
231 mpc_reg_out (®s->cr, I2C_EN, I2C_INIT_MASK);
232 mpc_reg_out (®s->sr, 0, I2C_IF);
236 static int mpc_get_fdr (int speed)
241 ulong best_speed = 0;
244 ulong bestmatch = 0xffffffffUL;
245 int best_i = 0, best_j = 0, i, j;
246 int SCL_Tap[] = { 9, 10, 12, 15, 5, 6, 7, 8 };
247 struct mpc8220_i2c_tap scltap[] = {
259 for (i = 7; i >= 0; i--) {
260 for (j = 7; j >= 0; j--) {
261 scl = 2 * (scltap[j].scl2tap +
263 1) * scltap[j].tap2tap + 2);
264 if (ipb <= speed * scl) {
265 if ((speed * scl - ipb) < bestmatch) {
266 bestmatch = speed * scl - ipb;
269 best_speed = ipb / scl;
274 divider = (best_i & 3) | ((best_i & 4) << 3) | (best_j << 2);
275 if (gd->flags & GD_FLG_RELOC) {
278 printf ("%ld kHz, ", best_speed / 1000);
286 int i2c_probe (uchar chip)
288 i2c_t *regs = (i2c_t *) MMAP_I2C;
291 for (i = 0; i < I2C_RETRIES; i++) {
292 mpc_reg_out (®s->cr, I2C_STA, I2C_STA);
294 if (!do_address (chip, 0)) {
295 mpc_reg_out (®s->cr, 0, I2C_STA);
299 mpc_reg_out (®s->cr, 0, I2C_STA);
303 return (i == I2C_RETRIES);
306 int i2c_read (uchar chip, uint addr, int alen, uchar * buf, int len)
309 i2c_t *regs = (i2c_t *) MMAP_I2C;
312 xaddr[0] = (addr >> 24) & 0xFF;
313 xaddr[1] = (addr >> 16) & 0xFF;
314 xaddr[2] = (addr >> 8) & 0xFF;
315 xaddr[3] = addr & 0xFF;
317 if (wait_for_bb ()) {
318 printf ("i2c_read: bus is busy\n");
322 mpc_reg_out (®s->cr, I2C_STA, I2C_STA);
323 if (do_address (chip, 0)) {
324 printf ("i2c_read: failed to address chip\n");
328 if (send_bytes (chip, (char *)&xaddr[4 - alen], alen)) {
329 printf ("i2c_read: send_bytes failed\n");
333 mpc_reg_out (®s->cr, I2C_RSTA, I2C_RSTA);
334 if (do_address (chip, 1)) {
335 printf ("i2c_read: failed to address chip\n");
339 if (receive_bytes (chip, (char *)buf, len)) {
340 printf ("i2c_read: receive_bytes failed\n");
346 mpc_reg_out (®s->cr, 0, I2C_STA);
350 int i2c_write (uchar chip, uint addr, int alen, uchar * buf, int len)
353 i2c_t *regs = (i2c_t *) MMAP_I2C;
356 xaddr[0] = (addr >> 24) & 0xFF;
357 xaddr[1] = (addr >> 16) & 0xFF;
358 xaddr[2] = (addr >> 8) & 0xFF;
359 xaddr[3] = addr & 0xFF;
361 if (wait_for_bb ()) {
362 printf ("i2c_write: bus is busy\n");
366 mpc_reg_out (®s->cr, I2C_STA, I2C_STA);
367 if (do_address (chip, 0)) {
368 printf ("i2c_write: failed to address chip\n");
372 if (send_bytes (chip, (char *)&xaddr[4 - alen], alen)) {
373 printf ("i2c_write: send_bytes failed\n");
377 if (send_bytes (chip, (char *)buf, len)) {
378 printf ("i2c_write: send_bytes failed\n");
384 mpc_reg_out (®s->cr, 0, I2C_STA);
388 #endif /* CONFIG_HARD_I2C */