1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Freescale CPM1/CPM2 I2C interface.
4 * Copyright (c) 1999 Dan Malek (dmalek@jlc.net).
6 * moved into proper i2c interface;
7 * Brad Parker (brad@heeltoe.com)
9 * Parts from dbox2_i2c.c (cvs.tuxbox.org)
10 * (C) 2000-2001 Felix Domke (tmbinc@gmx.net), Gillem (htoa@gmx.net)
12 * (C) 2007 Montavista Software, Inc.
13 * Vitaly Bordug <vitb@kernel.crashing.org>
15 * Converted to of_platform_device. Renamed to i2c-cpm.c.
16 * (C) 2007,2008 Jochen Friedrich <jochen@scram.de>
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/delay.h>
22 #include <linux/slab.h>
23 #include <linux/interrupt.h>
24 #include <linux/errno.h>
25 #include <linux/stddef.h>
26 #include <linux/i2c.h>
28 #include <linux/dma-mapping.h>
29 #include <linux/of_address.h>
30 #include <linux/of_device.h>
31 #include <linux/of_irq.h>
32 #include <linux/of_platform.h>
33 #include <sysdev/fsl_soc.h>
36 /* Try to define this if you have an older CPU (earlier than rev D4) */
37 /* However, better use a GPIO based bitbang driver in this case :/ */
38 #undef I2C_CHIP_ERRATA
40 #define CPM_MAX_READ 513
43 #define I2C_EB (0x10) /* Big endian mode */
44 #define I2C_EB_CPM2 (0x30) /* Big endian mode, memory snoop */
46 #define DPRAM_BASE ((u8 __iomem __force *)cpm_muram_addr(0))
48 /* I2C parameter RAM. */
50 ushort rbase; /* Rx Buffer descriptor base address */
51 ushort tbase; /* Tx Buffer descriptor base address */
52 u_char rfcr; /* Rx function code */
53 u_char tfcr; /* Tx function code */
54 ushort mrblr; /* Max receive buffer length */
55 uint rstate; /* Internal */
56 uint rdp; /* Internal */
57 ushort rbptr; /* Rx Buffer descriptor pointer */
58 ushort rbc; /* Internal */
59 uint rxtmp; /* Internal */
60 uint tstate; /* Internal */
61 uint tdp; /* Internal */
62 ushort tbptr; /* Tx Buffer descriptor pointer */
63 ushort tbc; /* Internal */
64 uint txtmp; /* Internal */
65 char res1[4]; /* Reserved */
66 ushort rpbase; /* Relocation pointer */
67 char res2[2]; /* Reserved */
70 #define I2COM_START 0x80
71 #define I2COM_MASTER 0x01
72 #define I2CER_TXE 0x10
73 #define I2CER_BUSY 0x04
74 #define I2CER_TXB 0x02
75 #define I2CER_RXB 0x01
95 struct platform_device *ofdev;
96 struct i2c_adapter adap;
98 int version; /* CPM1=1, CPM2=2 */
102 struct i2c_reg __iomem *i2c_reg;
103 struct i2c_ram __iomem *i2c_ram;
105 wait_queue_head_t i2c_wait;
106 cbd_t __iomem *tbase;
107 cbd_t __iomem *rbase;
108 u_char *txbuf[CPM_MAXBD];
109 u_char *rxbuf[CPM_MAXBD];
110 dma_addr_t txdma[CPM_MAXBD];
111 dma_addr_t rxdma[CPM_MAXBD];
114 static irqreturn_t cpm_i2c_interrupt(int irq, void *dev_id)
117 struct i2c_reg __iomem *i2c_reg;
118 struct i2c_adapter *adap = dev_id;
121 cpm = i2c_get_adapdata(dev_id);
122 i2c_reg = cpm->i2c_reg;
124 /* Clear interrupt. */
125 i = in_8(&i2c_reg->i2cer);
126 out_8(&i2c_reg->i2cer, i);
128 dev_dbg(&adap->dev, "Interrupt: %x\n", i);
130 wake_up(&cpm->i2c_wait);
132 return i ? IRQ_HANDLED : IRQ_NONE;
135 static void cpm_reset_i2c_params(struct cpm_i2c *cpm)
137 struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
139 /* Set up the I2C parameters in the parameter ram. */
140 out_be16(&i2c_ram->tbase, (u8 __iomem *)cpm->tbase - DPRAM_BASE);
141 out_be16(&i2c_ram->rbase, (u8 __iomem *)cpm->rbase - DPRAM_BASE);
143 if (cpm->version == 1) {
144 out_8(&i2c_ram->tfcr, I2C_EB);
145 out_8(&i2c_ram->rfcr, I2C_EB);
147 out_8(&i2c_ram->tfcr, I2C_EB_CPM2);
148 out_8(&i2c_ram->rfcr, I2C_EB_CPM2);
151 out_be16(&i2c_ram->mrblr, CPM_MAX_READ);
153 out_be32(&i2c_ram->rstate, 0);
154 out_be32(&i2c_ram->rdp, 0);
155 out_be16(&i2c_ram->rbptr, 0);
156 out_be16(&i2c_ram->rbc, 0);
157 out_be32(&i2c_ram->rxtmp, 0);
158 out_be32(&i2c_ram->tstate, 0);
159 out_be32(&i2c_ram->tdp, 0);
160 out_be16(&i2c_ram->tbptr, 0);
161 out_be16(&i2c_ram->tbc, 0);
162 out_be32(&i2c_ram->txtmp, 0);
165 static void cpm_i2c_force_close(struct i2c_adapter *adap)
167 struct cpm_i2c *cpm = i2c_get_adapdata(adap);
168 struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
170 dev_dbg(&adap->dev, "cpm_i2c_force_close()\n");
172 cpm_command(cpm->cp_command, CPM_CR_CLOSE_RX_BD);
174 out_8(&i2c_reg->i2cmr, 0x00); /* Disable all interrupts */
175 out_8(&i2c_reg->i2cer, 0xff);
178 static void cpm_i2c_parse_message(struct i2c_adapter *adap,
179 struct i2c_msg *pmsg, int num, int tx, int rx)
186 struct cpm_i2c *cpm = i2c_get_adapdata(adap);
188 tbdf = cpm->tbase + tx;
189 rbdf = cpm->rbase + rx;
191 addr = i2c_8bit_addr_from_msg(pmsg);
196 /* Align read buffer */
197 rb = (u_char *) (((ulong) rb + 1) & ~1);
199 tb[0] = addr; /* Device address byte w/rw flag */
201 out_be16(&tbdf->cbd_datlen, pmsg->len + 1);
202 out_be16(&tbdf->cbd_sc, 0);
204 if (!(pmsg->flags & I2C_M_NOSTART))
205 setbits16(&tbdf->cbd_sc, BD_I2C_START);
208 setbits16(&tbdf->cbd_sc, BD_SC_LAST | BD_SC_WRAP);
210 if (pmsg->flags & I2C_M_RD) {
212 * To read, we need an empty buffer of the proper length.
213 * All that is used is the first byte for address, the remainder
214 * is just used for timing (and doesn't really have to exist).
217 dev_dbg(&adap->dev, "cpm_i2c_read(abyte=0x%x)\n", addr);
219 out_be16(&rbdf->cbd_datlen, 0);
220 out_be16(&rbdf->cbd_sc, BD_SC_EMPTY | BD_SC_INTRPT);
222 if (rx + 1 == CPM_MAXBD)
223 setbits16(&rbdf->cbd_sc, BD_SC_WRAP);
226 setbits16(&tbdf->cbd_sc, BD_SC_READY);
228 dev_dbg(&adap->dev, "cpm_i2c_write(abyte=0x%x)\n", addr);
230 memcpy(tb+1, pmsg->buf, pmsg->len);
233 setbits16(&tbdf->cbd_sc, BD_SC_READY | BD_SC_INTRPT);
237 static int cpm_i2c_check_message(struct i2c_adapter *adap,
238 struct i2c_msg *pmsg, int tx, int rx)
244 struct cpm_i2c *cpm = i2c_get_adapdata(adap);
246 tbdf = cpm->tbase + tx;
247 rbdf = cpm->rbase + rx;
252 /* Align read buffer */
253 rb = (u_char *) (((uint) rb + 1) & ~1);
256 if (pmsg->flags & I2C_M_RD) {
257 dev_dbg(&adap->dev, "tx sc 0x%04x, rx sc 0x%04x\n",
258 in_be16(&tbdf->cbd_sc), in_be16(&rbdf->cbd_sc));
260 if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
261 dev_dbg(&adap->dev, "I2C read; No ack\n");
264 if (in_be16(&rbdf->cbd_sc) & BD_SC_EMPTY) {
266 "I2C read; complete but rbuf empty\n");
269 if (in_be16(&rbdf->cbd_sc) & BD_SC_OV) {
270 dev_err(&adap->dev, "I2C read; Overrun\n");
273 memcpy(pmsg->buf, rb, pmsg->len);
275 dev_dbg(&adap->dev, "tx sc %d 0x%04x\n", tx,
276 in_be16(&tbdf->cbd_sc));
278 if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
279 dev_dbg(&adap->dev, "I2C write; No ack\n");
282 if (in_be16(&tbdf->cbd_sc) & BD_SC_UN) {
283 dev_err(&adap->dev, "I2C write; Underrun\n");
286 if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
287 dev_err(&adap->dev, "I2C write; Collision\n");
294 static int cpm_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
296 struct cpm_i2c *cpm = i2c_get_adapdata(adap);
297 struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
298 struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
299 struct i2c_msg *pmsg;
306 /* Reset to use first buffer */
307 out_be16(&i2c_ram->rbptr, in_be16(&i2c_ram->rbase));
308 out_be16(&i2c_ram->tbptr, in_be16(&i2c_ram->tbase));
317 * If there was a collision in the last i2c transaction,
318 * Set I2COM_MASTER as it was cleared during collision.
320 if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
321 out_8(&cpm->i2c_reg->i2com, I2COM_MASTER);
326 dev_dbg(&adap->dev, "R: %d T: %d\n", rptr, tptr);
328 cpm_i2c_parse_message(adap, pmsg, num, tptr, rptr);
329 if (pmsg->flags & I2C_M_RD)
333 /* Start transfer now */
334 /* Enable RX/TX/Error interupts */
335 out_8(&i2c_reg->i2cmr, I2CER_TXE | I2CER_TXB | I2CER_RXB);
336 out_8(&i2c_reg->i2cer, 0xff); /* Clear interrupt status */
337 /* Chip bug, set enable here */
338 setbits8(&i2c_reg->i2mod, I2MOD_EN); /* Enable */
339 /* Begin transmission */
340 setbits8(&i2c_reg->i2com, I2COM_START);
346 /* Check for outstanding messages */
347 dev_dbg(&adap->dev, "test ready.\n");
349 if (pmsg->flags & I2C_M_RD)
350 ret = wait_event_timeout(cpm->i2c_wait,
351 (in_be16(&tbdf[tptr].cbd_sc) & BD_SC_NAK) ||
352 !(in_be16(&rbdf[rptr].cbd_sc) & BD_SC_EMPTY),
355 ret = wait_event_timeout(cpm->i2c_wait,
356 !(in_be16(&tbdf[tptr].cbd_sc) & BD_SC_READY),
360 dev_err(&adap->dev, "I2C transfer: timeout\n");
364 dev_dbg(&adap->dev, "ready.\n");
365 ret = cpm_i2c_check_message(adap, pmsg, tptr, rptr);
367 if (pmsg->flags & I2C_M_RD)
373 #ifdef I2C_CHIP_ERRATA
375 * Chip errata, clear enable. This is not needed on rev D4 CPUs.
376 * Disabling I2C too early may cause too short stop condition
379 clrbits8(&i2c_reg->i2mod, I2MOD_EN);
384 cpm_i2c_force_close(adap);
385 #ifdef I2C_CHIP_ERRATA
387 * Chip errata, clear enable. This is not needed on rev D4 CPUs.
389 clrbits8(&i2c_reg->i2mod, I2MOD_EN);
394 static u32 cpm_i2c_func(struct i2c_adapter *adap)
396 return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
399 /* -----exported algorithm data: ------------------------------------- */
401 static const struct i2c_algorithm cpm_i2c_algo = {
402 .master_xfer = cpm_i2c_xfer,
403 .functionality = cpm_i2c_func,
406 /* CPM_MAX_READ is also limiting writes according to the code! */
407 static const struct i2c_adapter_quirks cpm_i2c_quirks = {
408 .max_num_msgs = CPM_MAXBD,
409 .max_read_len = CPM_MAX_READ,
410 .max_write_len = CPM_MAX_READ,
413 static const struct i2c_adapter cpm_ops = {
414 .owner = THIS_MODULE,
416 .algo = &cpm_i2c_algo,
417 .quirks = &cpm_i2c_quirks,
420 static int cpm_i2c_setup(struct cpm_i2c *cpm)
422 struct platform_device *ofdev = cpm->ofdev;
425 void __iomem *i2c_base;
430 dev_dbg(&cpm->ofdev->dev, "cpm_i2c_setup()\n");
432 init_waitqueue_head(&cpm->i2c_wait);
434 cpm->irq = irq_of_parse_and_map(ofdev->dev.of_node, 0);
438 /* Install interrupt handler. */
439 ret = request_irq(cpm->irq, cpm_i2c_interrupt, 0, "cpm_i2c",
444 /* I2C parameter RAM */
445 i2c_base = of_iomap(ofdev->dev.of_node, 1);
446 if (i2c_base == NULL) {
451 if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm1-i2c")) {
453 /* Check for and use a microcode relocation patch. */
454 cpm->i2c_ram = i2c_base;
455 cpm->i2c_addr = in_be16(&cpm->i2c_ram->rpbase);
458 * Maybe should use cpm_muram_alloc instead of hardcoding
459 * this in micropatch.c
462 cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
468 } else if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm2-i2c")) {
469 cpm->i2c_addr = cpm_muram_alloc(sizeof(struct i2c_ram), 64);
470 cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
471 out_be16(i2c_base, cpm->i2c_addr);
482 /* I2C control/status registers */
483 cpm->i2c_reg = of_iomap(ofdev->dev.of_node, 0);
484 if (cpm->i2c_reg == NULL) {
489 data = of_get_property(ofdev->dev.of_node, "fsl,cpm-command", &len);
490 if (!data || len != 4) {
494 cpm->cp_command = *data;
496 data = of_get_property(ofdev->dev.of_node, "linux,i2c-class", &len);
497 if (data && len == 4)
498 cpm->adap.class = *data;
500 data = of_get_property(ofdev->dev.of_node, "clock-frequency", &len);
501 if (data && len == 4)
504 cpm->freq = 60000; /* use 60kHz i2c clock by default */
507 * Allocate space for CPM_MAXBD transmit and receive buffer
508 * descriptors in the DP ram.
510 cpm->dp_addr = cpm_muram_alloc(sizeof(cbd_t) * 2 * CPM_MAXBD, 8);
516 cpm->tbase = cpm_muram_addr(cpm->dp_addr);
517 cpm->rbase = cpm_muram_addr(cpm->dp_addr + sizeof(cbd_t) * CPM_MAXBD);
519 /* Allocate TX and RX buffers */
524 for (i = 0; i < CPM_MAXBD; i++) {
525 cpm->rxbuf[i] = dma_alloc_coherent(&cpm->ofdev->dev,
527 &cpm->rxdma[i], GFP_KERNEL);
528 if (!cpm->rxbuf[i]) {
532 out_be32(&rbdf[i].cbd_bufaddr, ((cpm->rxdma[i] + 1) & ~1));
534 cpm->txbuf[i] = dma_alloc_coherent(&cpm->ofdev->dev,
536 &cpm->txdma[i], GFP_KERNEL);
537 if (!cpm->txbuf[i]) {
541 out_be32(&tbdf[i].cbd_bufaddr, cpm->txdma[i]);
544 /* Initialize Tx/Rx parameters. */
546 cpm_reset_i2c_params(cpm);
548 dev_dbg(&cpm->ofdev->dev, "i2c_ram 0x%p, i2c_addr 0x%04x, freq %d\n",
549 cpm->i2c_ram, cpm->i2c_addr, cpm->freq);
550 dev_dbg(&cpm->ofdev->dev, "tbase 0x%04x, rbase 0x%04x\n",
551 (u8 __iomem *)cpm->tbase - DPRAM_BASE,
552 (u8 __iomem *)cpm->rbase - DPRAM_BASE);
554 cpm_command(cpm->cp_command, CPM_CR_INIT_TRX);
557 * Select an invalid address. Just make sure we don't use loopback mode
559 out_8(&cpm->i2c_reg->i2add, 0x7f << 1);
562 * PDIV is set to 00 in i2mod, so brgclk/32 is used as input to the
563 * i2c baud rate generator. This is divided by 2 x (DIV + 3) to get
564 * the actual i2c bus frequency.
566 brg = get_brgfreq() / (32 * 2 * cpm->freq) - 3;
567 out_8(&cpm->i2c_reg->i2brg, brg);
569 out_8(&cpm->i2c_reg->i2mod, 0x00);
570 out_8(&cpm->i2c_reg->i2com, I2COM_MASTER); /* Master mode */
572 /* Disable interrupts. */
573 out_8(&cpm->i2c_reg->i2cmr, 0);
574 out_8(&cpm->i2c_reg->i2cer, 0xff);
579 for (i = 0; i < CPM_MAXBD; i++) {
581 dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
582 cpm->rxbuf[i], cpm->rxdma[i]);
584 dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
585 cpm->txbuf[i], cpm->txdma[i]);
587 cpm_muram_free(cpm->dp_addr);
589 iounmap(cpm->i2c_reg);
591 if ((cpm->version == 1) && (!cpm->i2c_addr))
592 iounmap(cpm->i2c_ram);
593 if (cpm->version == 2)
594 cpm_muram_free(cpm->i2c_addr);
596 free_irq(cpm->irq, &cpm->adap);
600 static void cpm_i2c_shutdown(struct cpm_i2c *cpm)
605 clrbits8(&cpm->i2c_reg->i2mod, I2MOD_EN);
607 /* Disable interrupts */
608 out_8(&cpm->i2c_reg->i2cmr, 0);
609 out_8(&cpm->i2c_reg->i2cer, 0xff);
611 free_irq(cpm->irq, &cpm->adap);
613 /* Free all memory */
614 for (i = 0; i < CPM_MAXBD; i++) {
615 dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
616 cpm->rxbuf[i], cpm->rxdma[i]);
617 dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
618 cpm->txbuf[i], cpm->txdma[i]);
621 cpm_muram_free(cpm->dp_addr);
622 iounmap(cpm->i2c_reg);
624 if ((cpm->version == 1) && (!cpm->i2c_addr))
625 iounmap(cpm->i2c_ram);
626 if (cpm->version == 2)
627 cpm_muram_free(cpm->i2c_addr);
630 static int cpm_i2c_probe(struct platform_device *ofdev)
636 cpm = kzalloc(sizeof(struct cpm_i2c), GFP_KERNEL);
642 platform_set_drvdata(ofdev, cpm);
645 i2c_set_adapdata(&cpm->adap, cpm);
646 cpm->adap.dev.parent = &ofdev->dev;
647 cpm->adap.dev.of_node = of_node_get(ofdev->dev.of_node);
649 result = cpm_i2c_setup(cpm);
651 dev_err(&ofdev->dev, "Unable to init hardware\n");
655 /* register new adapter to i2c module... */
657 data = of_get_property(ofdev->dev.of_node, "linux,i2c-index", &len);
658 cpm->adap.nr = (data && len == 4) ? be32_to_cpup(data) : -1;
659 result = i2c_add_numbered_adapter(&cpm->adap);
664 dev_dbg(&ofdev->dev, "hw routines for %s registered.\n",
669 cpm_i2c_shutdown(cpm);
676 static int cpm_i2c_remove(struct platform_device *ofdev)
678 struct cpm_i2c *cpm = platform_get_drvdata(ofdev);
680 i2c_del_adapter(&cpm->adap);
682 cpm_i2c_shutdown(cpm);
689 static const struct of_device_id cpm_i2c_match[] = {
691 .compatible = "fsl,cpm1-i2c",
694 .compatible = "fsl,cpm2-i2c",
699 MODULE_DEVICE_TABLE(of, cpm_i2c_match);
701 static struct platform_driver cpm_i2c_driver = {
702 .probe = cpm_i2c_probe,
703 .remove = cpm_i2c_remove,
705 .name = "fsl-i2c-cpm",
706 .of_match_table = cpm_i2c_match,
710 module_platform_driver(cpm_i2c_driver);
712 MODULE_AUTHOR("Jochen Friedrich <jochen@scram.de>");
713 MODULE_DESCRIPTION("I2C-Bus adapter routines for CPM boards");
714 MODULE_LICENSE("GPL");