2 * Freescale CPM1/CPM2 I2C interface.
3 * Copyright (c) 1999 Dan Malek (dmalek@jlc.net).
5 * moved into proper i2c interface;
6 * Brad Parker (brad@heeltoe.com)
8 * Parts from dbox2_i2c.c (cvs.tuxbox.org)
9 * (C) 2000-2001 Felix Domke (tmbinc@gmx.net), Gillem (htoa@gmx.net)
11 * (C) 2007 Montavista Software, Inc.
12 * Vitaly Bordug <vitb@kernel.crashing.org>
14 * Converted to of_platform_device. Renamed to i2c-cpm.c.
15 * (C) 2007,2008 Jochen Friedrich <jochen@scram.de>
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation; either version 2 of the License, or
20 * (at your option) any later version.
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU General Public License for more details.
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <linux/delay.h>
31 #include <linux/slab.h>
32 #include <linux/interrupt.h>
33 #include <linux/errno.h>
34 #include <linux/stddef.h>
35 #include <linux/i2c.h>
37 #include <linux/dma-mapping.h>
38 #include <linux/of_address.h>
39 #include <linux/of_device.h>
40 #include <linux/of_irq.h>
41 #include <linux/of_platform.h>
42 #include <sysdev/fsl_soc.h>
45 /* Try to define this if you have an older CPU (earlier than rev D4) */
46 /* However, better use a GPIO based bitbang driver in this case :/ */
47 #undef I2C_CHIP_ERRATA
49 #define CPM_MAX_READ 513
52 #define I2C_EB (0x10) /* Big endian mode */
53 #define I2C_EB_CPM2 (0x30) /* Big endian mode, memory snoop */
55 #define DPRAM_BASE ((u8 __iomem __force *)cpm_muram_addr(0))
57 /* I2C parameter RAM. */
59 ushort rbase
; /* Rx Buffer descriptor base address */
60 ushort tbase
; /* Tx Buffer descriptor base address */
61 u_char rfcr
; /* Rx function code */
62 u_char tfcr
; /* Tx function code */
63 ushort mrblr
; /* Max receive buffer length */
64 uint rstate
; /* Internal */
65 uint rdp
; /* Internal */
66 ushort rbptr
; /* Rx Buffer descriptor pointer */
67 ushort rbc
; /* Internal */
68 uint rxtmp
; /* Internal */
69 uint tstate
; /* Internal */
70 uint tdp
; /* Internal */
71 ushort tbptr
; /* Tx Buffer descriptor pointer */
72 ushort tbc
; /* Internal */
73 uint txtmp
; /* Internal */
74 char res1
[4]; /* Reserved */
75 ushort rpbase
; /* Relocation pointer */
76 char res2
[2]; /* Reserved */
79 #define I2COM_START 0x80
80 #define I2COM_MASTER 0x01
81 #define I2CER_TXE 0x10
82 #define I2CER_BUSY 0x04
83 #define I2CER_TXB 0x02
84 #define I2CER_RXB 0x01
104 struct platform_device
*ofdev
;
105 struct i2c_adapter adap
;
107 int version
; /* CPM1=1, CPM2=2 */
111 struct i2c_reg __iomem
*i2c_reg
;
112 struct i2c_ram __iomem
*i2c_ram
;
114 wait_queue_head_t i2c_wait
;
115 cbd_t __iomem
*tbase
;
116 cbd_t __iomem
*rbase
;
117 u_char
*txbuf
[CPM_MAXBD
];
118 u_char
*rxbuf
[CPM_MAXBD
];
119 dma_addr_t txdma
[CPM_MAXBD
];
120 dma_addr_t rxdma
[CPM_MAXBD
];
123 static irqreturn_t
cpm_i2c_interrupt(int irq
, void *dev_id
)
126 struct i2c_reg __iomem
*i2c_reg
;
127 struct i2c_adapter
*adap
= dev_id
;
130 cpm
= i2c_get_adapdata(dev_id
);
131 i2c_reg
= cpm
->i2c_reg
;
133 /* Clear interrupt. */
134 i
= in_8(&i2c_reg
->i2cer
);
135 out_8(&i2c_reg
->i2cer
, i
);
137 dev_dbg(&adap
->dev
, "Interrupt: %x\n", i
);
139 wake_up(&cpm
->i2c_wait
);
141 return i
? IRQ_HANDLED
: IRQ_NONE
;
144 static void cpm_reset_i2c_params(struct cpm_i2c
*cpm
)
146 struct i2c_ram __iomem
*i2c_ram
= cpm
->i2c_ram
;
148 /* Set up the I2C parameters in the parameter ram. */
149 out_be16(&i2c_ram
->tbase
, (u8 __iomem
*)cpm
->tbase
- DPRAM_BASE
);
150 out_be16(&i2c_ram
->rbase
, (u8 __iomem
*)cpm
->rbase
- DPRAM_BASE
);
152 if (cpm
->version
== 1) {
153 out_8(&i2c_ram
->tfcr
, I2C_EB
);
154 out_8(&i2c_ram
->rfcr
, I2C_EB
);
156 out_8(&i2c_ram
->tfcr
, I2C_EB_CPM2
);
157 out_8(&i2c_ram
->rfcr
, I2C_EB_CPM2
);
160 out_be16(&i2c_ram
->mrblr
, CPM_MAX_READ
);
162 out_be32(&i2c_ram
->rstate
, 0);
163 out_be32(&i2c_ram
->rdp
, 0);
164 out_be16(&i2c_ram
->rbptr
, 0);
165 out_be16(&i2c_ram
->rbc
, 0);
166 out_be32(&i2c_ram
->rxtmp
, 0);
167 out_be32(&i2c_ram
->tstate
, 0);
168 out_be32(&i2c_ram
->tdp
, 0);
169 out_be16(&i2c_ram
->tbptr
, 0);
170 out_be16(&i2c_ram
->tbc
, 0);
171 out_be32(&i2c_ram
->txtmp
, 0);
174 static void cpm_i2c_force_close(struct i2c_adapter
*adap
)
176 struct cpm_i2c
*cpm
= i2c_get_adapdata(adap
);
177 struct i2c_reg __iomem
*i2c_reg
= cpm
->i2c_reg
;
179 dev_dbg(&adap
->dev
, "cpm_i2c_force_close()\n");
181 cpm_command(cpm
->cp_command
, CPM_CR_CLOSE_RX_BD
);
183 out_8(&i2c_reg
->i2cmr
, 0x00); /* Disable all interrupts */
184 out_8(&i2c_reg
->i2cer
, 0xff);
187 static void cpm_i2c_parse_message(struct i2c_adapter
*adap
,
188 struct i2c_msg
*pmsg
, int num
, int tx
, int rx
)
195 struct cpm_i2c
*cpm
= i2c_get_adapdata(adap
);
197 tbdf
= cpm
->tbase
+ tx
;
198 rbdf
= cpm
->rbase
+ rx
;
200 addr
= i2c_8bit_addr_from_msg(pmsg
);
205 /* Align read buffer */
206 rb
= (u_char
*) (((ulong
) rb
+ 1) & ~1);
208 tb
[0] = addr
; /* Device address byte w/rw flag */
210 out_be16(&tbdf
->cbd_datlen
, pmsg
->len
+ 1);
211 out_be16(&tbdf
->cbd_sc
, 0);
213 if (!(pmsg
->flags
& I2C_M_NOSTART
))
214 setbits16(&tbdf
->cbd_sc
, BD_I2C_START
);
217 setbits16(&tbdf
->cbd_sc
, BD_SC_LAST
| BD_SC_WRAP
);
219 if (pmsg
->flags
& I2C_M_RD
) {
221 * To read, we need an empty buffer of the proper length.
222 * All that is used is the first byte for address, the remainder
223 * is just used for timing (and doesn't really have to exist).
226 dev_dbg(&adap
->dev
, "cpm_i2c_read(abyte=0x%x)\n", addr
);
228 out_be16(&rbdf
->cbd_datlen
, 0);
229 out_be16(&rbdf
->cbd_sc
, BD_SC_EMPTY
| BD_SC_INTRPT
);
231 if (rx
+ 1 == CPM_MAXBD
)
232 setbits16(&rbdf
->cbd_sc
, BD_SC_WRAP
);
235 setbits16(&tbdf
->cbd_sc
, BD_SC_READY
);
237 dev_dbg(&adap
->dev
, "cpm_i2c_write(abyte=0x%x)\n", addr
);
239 memcpy(tb
+1, pmsg
->buf
, pmsg
->len
);
242 setbits16(&tbdf
->cbd_sc
, BD_SC_READY
| BD_SC_INTRPT
);
246 static int cpm_i2c_check_message(struct i2c_adapter
*adap
,
247 struct i2c_msg
*pmsg
, int tx
, int rx
)
253 struct cpm_i2c
*cpm
= i2c_get_adapdata(adap
);
255 tbdf
= cpm
->tbase
+ tx
;
256 rbdf
= cpm
->rbase
+ rx
;
261 /* Align read buffer */
262 rb
= (u_char
*) (((uint
) rb
+ 1) & ~1);
265 if (pmsg
->flags
& I2C_M_RD
) {
266 dev_dbg(&adap
->dev
, "tx sc 0x%04x, rx sc 0x%04x\n",
267 in_be16(&tbdf
->cbd_sc
), in_be16(&rbdf
->cbd_sc
));
269 if (in_be16(&tbdf
->cbd_sc
) & BD_SC_NAK
) {
270 dev_dbg(&adap
->dev
, "I2C read; No ack\n");
273 if (in_be16(&rbdf
->cbd_sc
) & BD_SC_EMPTY
) {
275 "I2C read; complete but rbuf empty\n");
278 if (in_be16(&rbdf
->cbd_sc
) & BD_SC_OV
) {
279 dev_err(&adap
->dev
, "I2C read; Overrun\n");
282 memcpy(pmsg
->buf
, rb
, pmsg
->len
);
284 dev_dbg(&adap
->dev
, "tx sc %d 0x%04x\n", tx
,
285 in_be16(&tbdf
->cbd_sc
));
287 if (in_be16(&tbdf
->cbd_sc
) & BD_SC_NAK
) {
288 dev_dbg(&adap
->dev
, "I2C write; No ack\n");
291 if (in_be16(&tbdf
->cbd_sc
) & BD_SC_UN
) {
292 dev_err(&adap
->dev
, "I2C write; Underrun\n");
295 if (in_be16(&tbdf
->cbd_sc
) & BD_SC_CL
) {
296 dev_err(&adap
->dev
, "I2C write; Collision\n");
303 static int cpm_i2c_xfer(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
, int num
)
305 struct cpm_i2c
*cpm
= i2c_get_adapdata(adap
);
306 struct i2c_reg __iomem
*i2c_reg
= cpm
->i2c_reg
;
307 struct i2c_ram __iomem
*i2c_ram
= cpm
->i2c_ram
;
308 struct i2c_msg
*pmsg
;
315 /* Reset to use first buffer */
316 out_be16(&i2c_ram
->rbptr
, in_be16(&i2c_ram
->rbase
));
317 out_be16(&i2c_ram
->tbptr
, in_be16(&i2c_ram
->tbase
));
326 * If there was a collision in the last i2c transaction,
327 * Set I2COM_MASTER as it was cleared during collision.
329 if (in_be16(&tbdf
->cbd_sc
) & BD_SC_CL
) {
330 out_8(&cpm
->i2c_reg
->i2com
, I2COM_MASTER
);
335 dev_dbg(&adap
->dev
, "R: %d T: %d\n", rptr
, tptr
);
337 cpm_i2c_parse_message(adap
, pmsg
, num
, tptr
, rptr
);
338 if (pmsg
->flags
& I2C_M_RD
)
342 /* Start transfer now */
343 /* Enable RX/TX/Error interupts */
344 out_8(&i2c_reg
->i2cmr
, I2CER_TXE
| I2CER_TXB
| I2CER_RXB
);
345 out_8(&i2c_reg
->i2cer
, 0xff); /* Clear interrupt status */
346 /* Chip bug, set enable here */
347 setbits8(&i2c_reg
->i2mod
, I2MOD_EN
); /* Enable */
348 /* Begin transmission */
349 setbits8(&i2c_reg
->i2com
, I2COM_START
);
355 /* Check for outstanding messages */
356 dev_dbg(&adap
->dev
, "test ready.\n");
358 if (pmsg
->flags
& I2C_M_RD
)
359 ret
= wait_event_timeout(cpm
->i2c_wait
,
360 (in_be16(&tbdf
[tptr
].cbd_sc
) & BD_SC_NAK
) ||
361 !(in_be16(&rbdf
[rptr
].cbd_sc
) & BD_SC_EMPTY
),
364 ret
= wait_event_timeout(cpm
->i2c_wait
,
365 !(in_be16(&tbdf
[tptr
].cbd_sc
) & BD_SC_READY
),
369 dev_err(&adap
->dev
, "I2C transfer: timeout\n");
373 dev_dbg(&adap
->dev
, "ready.\n");
374 ret
= cpm_i2c_check_message(adap
, pmsg
, tptr
, rptr
);
376 if (pmsg
->flags
& I2C_M_RD
)
382 #ifdef I2C_CHIP_ERRATA
384 * Chip errata, clear enable. This is not needed on rev D4 CPUs.
385 * Disabling I2C too early may cause too short stop condition
388 clrbits8(&i2c_reg
->i2mod
, I2MOD_EN
);
393 cpm_i2c_force_close(adap
);
394 #ifdef I2C_CHIP_ERRATA
396 * Chip errata, clear enable. This is not needed on rev D4 CPUs.
398 clrbits8(&i2c_reg
->i2mod
, I2MOD_EN
);
403 static u32
cpm_i2c_func(struct i2c_adapter
*adap
)
405 return I2C_FUNC_I2C
| (I2C_FUNC_SMBUS_EMUL
& ~I2C_FUNC_SMBUS_QUICK
);
408 /* -----exported algorithm data: ------------------------------------- */
410 static const struct i2c_algorithm cpm_i2c_algo
= {
411 .master_xfer
= cpm_i2c_xfer
,
412 .functionality
= cpm_i2c_func
,
415 /* CPM_MAX_READ is also limiting writes according to the code! */
416 static const struct i2c_adapter_quirks cpm_i2c_quirks
= {
417 .max_num_msgs
= CPM_MAXBD
,
418 .max_read_len
= CPM_MAX_READ
,
419 .max_write_len
= CPM_MAX_READ
,
422 static const struct i2c_adapter cpm_ops
= {
423 .owner
= THIS_MODULE
,
425 .algo
= &cpm_i2c_algo
,
426 .quirks
= &cpm_i2c_quirks
,
429 static int cpm_i2c_setup(struct cpm_i2c
*cpm
)
431 struct platform_device
*ofdev
= cpm
->ofdev
;
434 void __iomem
*i2c_base
;
439 dev_dbg(&cpm
->ofdev
->dev
, "cpm_i2c_setup()\n");
441 init_waitqueue_head(&cpm
->i2c_wait
);
443 cpm
->irq
= irq_of_parse_and_map(ofdev
->dev
.of_node
, 0);
447 /* Install interrupt handler. */
448 ret
= request_irq(cpm
->irq
, cpm_i2c_interrupt
, 0, "cpm_i2c",
453 /* I2C parameter RAM */
454 i2c_base
= of_iomap(ofdev
->dev
.of_node
, 1);
455 if (i2c_base
== NULL
) {
460 if (of_device_is_compatible(ofdev
->dev
.of_node
, "fsl,cpm1-i2c")) {
462 /* Check for and use a microcode relocation patch. */
463 cpm
->i2c_ram
= i2c_base
;
464 cpm
->i2c_addr
= in_be16(&cpm
->i2c_ram
->rpbase
);
467 * Maybe should use cpm_muram_alloc instead of hardcoding
468 * this in micropatch.c
471 cpm
->i2c_ram
= cpm_muram_addr(cpm
->i2c_addr
);
477 } else if (of_device_is_compatible(ofdev
->dev
.of_node
, "fsl,cpm2-i2c")) {
478 cpm
->i2c_addr
= cpm_muram_alloc(sizeof(struct i2c_ram
), 64);
479 cpm
->i2c_ram
= cpm_muram_addr(cpm
->i2c_addr
);
480 out_be16(i2c_base
, cpm
->i2c_addr
);
491 /* I2C control/status registers */
492 cpm
->i2c_reg
= of_iomap(ofdev
->dev
.of_node
, 0);
493 if (cpm
->i2c_reg
== NULL
) {
498 data
= of_get_property(ofdev
->dev
.of_node
, "fsl,cpm-command", &len
);
499 if (!data
|| len
!= 4) {
503 cpm
->cp_command
= *data
;
505 data
= of_get_property(ofdev
->dev
.of_node
, "linux,i2c-class", &len
);
506 if (data
&& len
== 4)
507 cpm
->adap
.class = *data
;
509 data
= of_get_property(ofdev
->dev
.of_node
, "clock-frequency", &len
);
510 if (data
&& len
== 4)
513 cpm
->freq
= 60000; /* use 60kHz i2c clock by default */
516 * Allocate space for CPM_MAXBD transmit and receive buffer
517 * descriptors in the DP ram.
519 cpm
->dp_addr
= cpm_muram_alloc(sizeof(cbd_t
) * 2 * CPM_MAXBD
, 8);
525 cpm
->tbase
= cpm_muram_addr(cpm
->dp_addr
);
526 cpm
->rbase
= cpm_muram_addr(cpm
->dp_addr
+ sizeof(cbd_t
) * CPM_MAXBD
);
528 /* Allocate TX and RX buffers */
533 for (i
= 0; i
< CPM_MAXBD
; i
++) {
534 cpm
->rxbuf
[i
] = dma_alloc_coherent(&cpm
->ofdev
->dev
,
536 &cpm
->rxdma
[i
], GFP_KERNEL
);
537 if (!cpm
->rxbuf
[i
]) {
541 out_be32(&rbdf
[i
].cbd_bufaddr
, ((cpm
->rxdma
[i
] + 1) & ~1));
543 cpm
->txbuf
[i
] = (unsigned char *)dma_alloc_coherent(&cpm
->ofdev
->dev
, CPM_MAX_READ
+ 1, &cpm
->txdma
[i
], GFP_KERNEL
);
544 if (!cpm
->txbuf
[i
]) {
548 out_be32(&tbdf
[i
].cbd_bufaddr
, cpm
->txdma
[i
]);
551 /* Initialize Tx/Rx parameters. */
553 cpm_reset_i2c_params(cpm
);
555 dev_dbg(&cpm
->ofdev
->dev
, "i2c_ram 0x%p, i2c_addr 0x%04x, freq %d\n",
556 cpm
->i2c_ram
, cpm
->i2c_addr
, cpm
->freq
);
557 dev_dbg(&cpm
->ofdev
->dev
, "tbase 0x%04x, rbase 0x%04x\n",
558 (u8 __iomem
*)cpm
->tbase
- DPRAM_BASE
,
559 (u8 __iomem
*)cpm
->rbase
- DPRAM_BASE
);
561 cpm_command(cpm
->cp_command
, CPM_CR_INIT_TRX
);
564 * Select an invalid address. Just make sure we don't use loopback mode
566 out_8(&cpm
->i2c_reg
->i2add
, 0x7f << 1);
569 * PDIV is set to 00 in i2mod, so brgclk/32 is used as input to the
570 * i2c baud rate generator. This is divided by 2 x (DIV + 3) to get
571 * the actual i2c bus frequency.
573 brg
= get_brgfreq() / (32 * 2 * cpm
->freq
) - 3;
574 out_8(&cpm
->i2c_reg
->i2brg
, brg
);
576 out_8(&cpm
->i2c_reg
->i2mod
, 0x00);
577 out_8(&cpm
->i2c_reg
->i2com
, I2COM_MASTER
); /* Master mode */
579 /* Disable interrupts. */
580 out_8(&cpm
->i2c_reg
->i2cmr
, 0);
581 out_8(&cpm
->i2c_reg
->i2cer
, 0xff);
586 for (i
= 0; i
< CPM_MAXBD
; i
++) {
588 dma_free_coherent(&cpm
->ofdev
->dev
, CPM_MAX_READ
+ 1,
589 cpm
->rxbuf
[i
], cpm
->rxdma
[i
]);
591 dma_free_coherent(&cpm
->ofdev
->dev
, CPM_MAX_READ
+ 1,
592 cpm
->txbuf
[i
], cpm
->txdma
[i
]);
594 cpm_muram_free(cpm
->dp_addr
);
596 iounmap(cpm
->i2c_reg
);
598 if ((cpm
->version
== 1) && (!cpm
->i2c_addr
))
599 iounmap(cpm
->i2c_ram
);
600 if (cpm
->version
== 2)
601 cpm_muram_free(cpm
->i2c_addr
);
603 free_irq(cpm
->irq
, &cpm
->adap
);
607 static void cpm_i2c_shutdown(struct cpm_i2c
*cpm
)
612 clrbits8(&cpm
->i2c_reg
->i2mod
, I2MOD_EN
);
614 /* Disable interrupts */
615 out_8(&cpm
->i2c_reg
->i2cmr
, 0);
616 out_8(&cpm
->i2c_reg
->i2cer
, 0xff);
618 free_irq(cpm
->irq
, &cpm
->adap
);
620 /* Free all memory */
621 for (i
= 0; i
< CPM_MAXBD
; i
++) {
622 dma_free_coherent(&cpm
->ofdev
->dev
, CPM_MAX_READ
+ 1,
623 cpm
->rxbuf
[i
], cpm
->rxdma
[i
]);
624 dma_free_coherent(&cpm
->ofdev
->dev
, CPM_MAX_READ
+ 1,
625 cpm
->txbuf
[i
], cpm
->txdma
[i
]);
628 cpm_muram_free(cpm
->dp_addr
);
629 iounmap(cpm
->i2c_reg
);
631 if ((cpm
->version
== 1) && (!cpm
->i2c_addr
))
632 iounmap(cpm
->i2c_ram
);
633 if (cpm
->version
== 2)
634 cpm_muram_free(cpm
->i2c_addr
);
637 static int cpm_i2c_probe(struct platform_device
*ofdev
)
643 cpm
= kzalloc(sizeof(struct cpm_i2c
), GFP_KERNEL
);
649 platform_set_drvdata(ofdev
, cpm
);
652 i2c_set_adapdata(&cpm
->adap
, cpm
);
653 cpm
->adap
.dev
.parent
= &ofdev
->dev
;
654 cpm
->adap
.dev
.of_node
= of_node_get(ofdev
->dev
.of_node
);
656 result
= cpm_i2c_setup(cpm
);
658 dev_err(&ofdev
->dev
, "Unable to init hardware\n");
662 /* register new adapter to i2c module... */
664 data
= of_get_property(ofdev
->dev
.of_node
, "linux,i2c-index", &len
);
665 cpm
->adap
.nr
= (data
&& len
== 4) ? be32_to_cpup(data
) : -1;
666 result
= i2c_add_numbered_adapter(&cpm
->adap
);
671 dev_dbg(&ofdev
->dev
, "hw routines for %s registered.\n",
676 cpm_i2c_shutdown(cpm
);
683 static int cpm_i2c_remove(struct platform_device
*ofdev
)
685 struct cpm_i2c
*cpm
= platform_get_drvdata(ofdev
);
687 i2c_del_adapter(&cpm
->adap
);
689 cpm_i2c_shutdown(cpm
);
696 static const struct of_device_id cpm_i2c_match
[] = {
698 .compatible
= "fsl,cpm1-i2c",
701 .compatible
= "fsl,cpm2-i2c",
706 MODULE_DEVICE_TABLE(of
, cpm_i2c_match
);
708 static struct platform_driver cpm_i2c_driver
= {
709 .probe
= cpm_i2c_probe
,
710 .remove
= cpm_i2c_remove
,
712 .name
= "fsl-i2c-cpm",
713 .of_match_table
= cpm_i2c_match
,
717 module_platform_driver(cpm_i2c_driver
);
719 MODULE_AUTHOR("Jochen Friedrich <jochen@scram.de>");
720 MODULE_DESCRIPTION("I2C-Bus adapter routines for CPM boards");
721 MODULE_LICENSE("GPL");