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git.ipfire.org Git - people/ms/u-boot.git/blob - cpu/mpc512x/i2c.c
2 * (C) Copyright 2003 - 2007
3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
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,
23 * Based on the MPC5xxx code.
28 DECLARE_GLOBAL_DATA_PTR
;
30 #ifdef CONFIG_HARD_I2C
35 #define immr ((immap_t *)CFG_IMMR)
37 /* by default set I2C bus 0 active */
38 static unsigned int bus_num
= 0;
40 #define I2C_TIMEOUT 100
43 struct mpc512x_i2c_tap
{
48 static int mpc_reg_in(volatile u32
*reg
);
49 static void mpc_reg_out(volatile u32
*reg
, int val
, int mask
);
50 static int wait_for_bb(void);
51 static int wait_for_pin(int *status
);
52 static int do_address(uchar chip
, char rdwr_flag
);
53 static int send_bytes(uchar chip
, char *buf
, int len
);
54 static int receive_bytes(uchar chip
, char *buf
, int len
);
55 static int mpc_get_fdr(int);
57 static int mpc_reg_in (volatile u32
*reg
)
60 __asm__
__volatile__ ("eieio");
64 static void mpc_reg_out (volatile u32
*reg
, int val
, int mask
)
71 tmp
= mpc_reg_in (reg
);
72 *reg
= ((tmp
& ~mask
) | (val
& mask
)) << 24;
74 __asm__
__volatile__ ("eieio");
79 static int wait_for_bb (void)
81 i2c512x_dev_t
*regs
= &immr
->i2c
.dev
[bus_num
];
82 int timeout
= I2C_TIMEOUT
;
85 status
= mpc_reg_in (®s
->msr
);
87 while (timeout
-- && (status
& I2C_BB
)) {
89 mpc_reg_out (®s
->mcr
, I2C_STA
, I2C_STA
);
90 temp
= mpc_reg_in (®s
->mdr
);
91 mpc_reg_out (®s
->mcr
, 0, I2C_STA
);
92 mpc_reg_out (®s
->mcr
, 0, 0);
93 mpc_reg_out (®s
->mcr
, I2C_EN
, 0);
96 status
= mpc_reg_in (®s
->msr
);
99 return (status
& I2C_BB
);
102 static int wait_for_pin (int *status
)
104 i2c512x_dev_t
*regs
= &immr
->i2c
.dev
[bus_num
];
105 int timeout
= I2C_TIMEOUT
;
107 *status
= mpc_reg_in (®s
->msr
);
109 while (timeout
-- && !(*status
& I2C_IF
)) {
111 *status
= mpc_reg_in (®s
->msr
);
114 if (!(*status
& I2C_IF
)) {
118 mpc_reg_out (®s
->msr
, 0, I2C_IF
);
123 static int do_address (uchar chip
, char rdwr_flag
)
125 i2c512x_dev_t
*regs
= &immr
->i2c
.dev
[bus_num
];
134 mpc_reg_out (®s
->mcr
, I2C_TX
, I2C_TX
);
135 mpc_reg_out (®s
->mdr
, chip
, 0);
137 if (wait_for_pin (&status
)) {
141 if (status
& I2C_RXAK
) {
148 static int send_bytes (uchar chip
, char *buf
, int len
)
150 i2c512x_dev_t
*regs
= &immr
->i2c
.dev
[bus_num
];
154 for (wrcount
= 0; wrcount
< len
; ++wrcount
) {
156 mpc_reg_out (®s
->mdr
, buf
[wrcount
], 0);
158 if (wait_for_pin (&status
)) {
162 if (status
& I2C_RXAK
) {
168 return !(wrcount
== len
);
171 static int receive_bytes (uchar chip
, char *buf
, int len
)
173 i2c512x_dev_t
*regs
= &immr
->i2c
.dev
[bus_num
];
179 mpc_reg_out (®s
->mcr
, 0, I2C_TX
);
181 for (i
= 0; i
< len
; ++i
) {
182 buf
[rdcount
] = mpc_reg_in (®s
->mdr
);
190 if (wait_for_pin (&status
)) {
195 mpc_reg_out (®s
->mcr
, I2C_TXAK
, I2C_TXAK
);
196 buf
[rdcount
++] = mpc_reg_in (®s
->mdr
);
198 if (wait_for_pin (&status
)) {
202 mpc_reg_out (®s
->mcr
, 0, I2C_TXAK
);
207 /**************** I2C API ****************/
209 void i2c_init (int speed
, int saddr
)
212 for(i
= 0; i
< I2C_BUS_CNT
; i
++){
213 i2c512x_dev_t
*regs
= &immr
->i2c
.dev
[i
];
214 mpc_reg_out (®s
->mcr
, 0, 0);
217 mpc_reg_out (®s
->mfdr
, mpc_get_fdr (speed
), 0);
218 mpc_reg_out (®s
->madr
, saddr
<< 1, 0);
221 mpc_reg_out (®s
->mcr
, I2C_EN
, I2C_INIT_MASK
);
222 mpc_reg_out (®s
->msr
, 0, I2C_IF
);
225 /* Disable interrupts */
227 /* Turn off filters */
232 static int mpc_get_fdr (int speed
)
237 ulong best_speed
= 0;
240 ulong bestmatch
= 0xffffffffUL
;
241 int best_i
= 0, best_j
= 0, i
, j
;
242 int SCL_Tap
[] = { 9, 10, 12, 15, 5, 6, 7, 8};
243 struct mpc512x_i2c_tap scltap
[] = {
255 for (i
= 7; i
>= 0; i
--) {
256 for (j
= 7; j
>= 0; j
--) {
257 scl
= 2 * (scltap
[j
].scl2tap
+
258 (SCL_Tap
[i
] - 1) * scltap
[j
].tap2tap
260 if (ipb
<= speed
*scl
) {
261 if ((speed
*scl
- ipb
) < bestmatch
) {
262 bestmatch
= speed
*scl
- ipb
;
265 best_speed
= ipb
/scl
;
270 divider
= (best_i
& 3) | ((best_i
& 4) << 3) | (best_j
<< 2);
271 if (gd
->flags
& GD_FLG_RELOC
) {
274 debug("%ld kHz, \n", best_speed
/ 1000);
282 int i2c_probe (uchar chip
)
284 i2c512x_dev_t
*regs
= &immr
->i2c
.dev
[bus_num
];
287 for (i
= 0; i
< I2C_RETRIES
; i
++) {
288 mpc_reg_out (®s
->mcr
, I2C_STA
, I2C_STA
);
290 if (! do_address (chip
, 0)) {
291 mpc_reg_out (®s
->mcr
, 0, I2C_STA
);
296 mpc_reg_out (®s
->mcr
, 0, I2C_STA
);
300 return (i
== I2C_RETRIES
);
303 int i2c_read (uchar chip
, uint addr
, int alen
, uchar
*buf
, int len
)
306 i2c512x_dev_t
*regs
= &immr
->i2c
.dev
[bus_num
];
309 xaddr
[0] = (addr
>> 24) & 0xFF;
310 xaddr
[1] = (addr
>> 16) & 0xFF;
311 xaddr
[2] = (addr
>> 8) & 0xFF;
312 xaddr
[3] = addr
& 0xFF;
314 if (wait_for_bb ()) {
315 printf ("i2c_read: bus is busy\n");
319 mpc_reg_out (®s
->mcr
, I2C_STA
, I2C_STA
);
320 if (do_address (chip
, 0)) {
321 printf ("i2c_read: failed to address chip\n");
325 if (send_bytes (chip
, &xaddr
[4-alen
], alen
)) {
326 printf ("i2c_read: send_bytes failed\n");
330 mpc_reg_out (®s
->mcr
, I2C_RSTA
, I2C_RSTA
);
331 if (do_address (chip
, 1)) {
332 printf ("i2c_read: failed to address chip\n");
336 if (receive_bytes (chip
, (char *)buf
, len
)) {
337 printf ("i2c_read: receive_bytes failed\n");
343 mpc_reg_out (®s
->mcr
, 0, I2C_STA
);
347 int i2c_write (uchar chip
, uint addr
, int alen
, uchar
*buf
, int len
)
350 i2c512x_dev_t
*regs
= &immr
->i2c
.dev
[bus_num
];
353 xaddr
[0] = (addr
>> 24) & 0xFF;
354 xaddr
[1] = (addr
>> 16) & 0xFF;
355 xaddr
[2] = (addr
>> 8) & 0xFF;
356 xaddr
[3] = addr
& 0xFF;
358 if (wait_for_bb ()) {
359 printf ("i2c_write: bus is busy\n");
363 mpc_reg_out (®s
->mcr
, I2C_STA
, I2C_STA
);
364 if (do_address (chip
, 0)) {
365 printf ("i2c_write: failed to address chip\n");
369 if (send_bytes (chip
, &xaddr
[4-alen
], alen
)) {
370 printf ("i2c_write: send_bytes failed\n");
374 if (send_bytes (chip
, (char *)buf
, len
)) {
375 printf ("i2c_write: send_bytes failed\n");
381 mpc_reg_out (®s
->mcr
, 0, I2C_STA
);
385 uchar
i2c_reg_read (uchar chip
, uchar reg
)
389 i2c_read (chip
, reg
, 1, &buf
, 1);
394 void i2c_reg_write (uchar chip
, uchar reg
, uchar val
)
396 i2c_write (chip
, reg
, 1, &val
, 1);
402 int i2c_set_bus_num (unsigned int bus
)
404 if (bus
>= I2C_BUS_CNT
) {
412 unsigned int i2c_get_bus_num (void)
418 unsigned int i2c_get_bus_speed (void)
423 int i2c_set_bus_speed (unsigned int speed
)
425 if (speed
!= CFG_I2C_SPEED
)
431 #endif /* CONFIG_HARD_I2C */