2 * Freescale eSPI controller driver.
4 * Copyright 2010 Freescale Semiconductor, Inc.
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version.
11 #include <linux/module.h>
12 #include <linux/delay.h>
13 #include <linux/irq.h>
14 #include <linux/spi/spi.h>
15 #include <linux/platform_device.h>
16 #include <linux/fsl_devices.h>
19 #include <linux/of_platform.h>
20 #include <linux/interrupt.h>
21 #include <linux/err.h>
22 #include <sysdev/fsl_soc.h>
24 #include "spi-fsl-lib.h"
26 /* eSPI Controller registers */
28 __be32 mode
; /* 0x000 - eSPI mode register */
29 __be32 event
; /* 0x004 - eSPI event register */
30 __be32 mask
; /* 0x008 - eSPI mask register */
31 __be32 command
; /* 0x00c - eSPI command register */
32 __be32 transmit
; /* 0x010 - eSPI transmit FIFO access register*/
33 __be32 receive
; /* 0x014 - eSPI receive FIFO access register*/
34 u8 res
[8]; /* 0x018 - 0x01c reserved */
35 __be32 csmode
[4]; /* 0x020 - 0x02c eSPI cs mode register */
38 struct fsl_espi_transfer
{
44 unsigned actual_length
;
48 /* eSPI Controller mode register definitions */
49 #define SPMODE_ENABLE (1 << 31)
50 #define SPMODE_LOOP (1 << 30)
51 #define SPMODE_TXTHR(x) ((x) << 8)
52 #define SPMODE_RXTHR(x) ((x) << 0)
54 /* eSPI Controller CS mode register definitions */
55 #define CSMODE_CI_INACTIVEHIGH (1 << 31)
56 #define CSMODE_CP_BEGIN_EDGECLK (1 << 30)
57 #define CSMODE_REV (1 << 29)
58 #define CSMODE_DIV16 (1 << 28)
59 #define CSMODE_PM(x) ((x) << 24)
60 #define CSMODE_POL_1 (1 << 20)
61 #define CSMODE_LEN(x) ((x) << 16)
62 #define CSMODE_BEF(x) ((x) << 12)
63 #define CSMODE_AFT(x) ((x) << 8)
64 #define CSMODE_CG(x) ((x) << 3)
66 /* Default mode/csmode for eSPI controller */
67 #define SPMODE_INIT_VAL (SPMODE_TXTHR(4) | SPMODE_RXTHR(3))
68 #define CSMODE_INIT_VAL (CSMODE_POL_1 | CSMODE_BEF(0) \
69 | CSMODE_AFT(0) | CSMODE_CG(1))
71 /* SPIE register values */
72 #define SPIE_NE 0x00000200 /* Not empty */
73 #define SPIE_NF 0x00000100 /* Not full */
75 /* SPIM register values */
76 #define SPIM_NE 0x00000200 /* Not empty */
77 #define SPIM_NF 0x00000100 /* Not full */
78 #define SPIE_RXCNT(reg) ((reg >> 24) & 0x3F)
79 #define SPIE_TXCNT(reg) ((reg >> 16) & 0x3F)
81 /* SPCOM register values */
82 #define SPCOM_CS(x) ((x) << 30)
83 #define SPCOM_TRANLEN(x) ((x) << 0)
84 #define SPCOM_TRANLEN_MAX 0xFFFF /* Max transaction length */
86 static void fsl_espi_change_mode(struct spi_device
*spi
)
88 struct mpc8xxx_spi
*mspi
= spi_master_get_devdata(spi
->master
);
89 struct spi_mpc8xxx_cs
*cs
= spi
->controller_state
;
90 struct fsl_espi_reg
*reg_base
= mspi
->reg_base
;
91 __be32 __iomem
*mode
= ®_base
->csmode
[spi
->chip_select
];
92 __be32 __iomem
*espi_mode
= ®_base
->mode
;
96 /* Turn off IRQs locally to minimize time that SPI is disabled. */
97 local_irq_save(flags
);
99 /* Turn off SPI unit prior changing mode */
100 tmp
= mpc8xxx_spi_read_reg(espi_mode
);
101 mpc8xxx_spi_write_reg(espi_mode
, tmp
& ~SPMODE_ENABLE
);
102 mpc8xxx_spi_write_reg(mode
, cs
->hw_mode
);
103 mpc8xxx_spi_write_reg(espi_mode
, tmp
);
105 local_irq_restore(flags
);
108 static u32
fsl_espi_tx_buf_lsb(struct mpc8xxx_spi
*mpc8xxx_spi
)
113 const u32
*tx
= mpc8xxx_spi
->tx
;
118 data
= *tx
++ << mpc8xxx_spi
->tx_shift
;
119 data_l
= data
& 0xffff;
120 data_h
= (data
>> 16) & 0xffff;
123 data
= data_h
| data_l
;
125 mpc8xxx_spi
->tx
= tx
;
129 static int fsl_espi_setup_transfer(struct spi_device
*spi
,
130 struct spi_transfer
*t
)
132 struct mpc8xxx_spi
*mpc8xxx_spi
= spi_master_get_devdata(spi
->master
);
133 int bits_per_word
= 0;
136 struct spi_mpc8xxx_cs
*cs
= spi
->controller_state
;
139 bits_per_word
= t
->bits_per_word
;
143 /* spi_transfer level calls that work per-word */
145 bits_per_word
= spi
->bits_per_word
;
148 hz
= spi
->max_speed_hz
;
152 cs
->get_rx
= mpc8xxx_spi_rx_buf_u32
;
153 cs
->get_tx
= mpc8xxx_spi_tx_buf_u32
;
154 if (bits_per_word
<= 8) {
155 cs
->rx_shift
= 8 - bits_per_word
;
157 cs
->rx_shift
= 16 - bits_per_word
;
158 if (spi
->mode
& SPI_LSB_FIRST
)
159 cs
->get_tx
= fsl_espi_tx_buf_lsb
;
162 mpc8xxx_spi
->rx_shift
= cs
->rx_shift
;
163 mpc8xxx_spi
->tx_shift
= cs
->tx_shift
;
164 mpc8xxx_spi
->get_rx
= cs
->get_rx
;
165 mpc8xxx_spi
->get_tx
= cs
->get_tx
;
167 bits_per_word
= bits_per_word
- 1;
169 /* mask out bits we are going to set */
170 cs
->hw_mode
&= ~(CSMODE_LEN(0xF) | CSMODE_DIV16
| CSMODE_PM(0xF));
172 cs
->hw_mode
|= CSMODE_LEN(bits_per_word
);
174 if ((mpc8xxx_spi
->spibrg
/ hz
) > 64) {
175 cs
->hw_mode
|= CSMODE_DIV16
;
176 pm
= DIV_ROUND_UP(mpc8xxx_spi
->spibrg
, hz
* 16 * 4);
178 WARN_ONCE(pm
> 33, "%s: Requested speed is too low: %d Hz. "
179 "Will use %d Hz instead.\n", dev_name(&spi
->dev
),
180 hz
, mpc8xxx_spi
->spibrg
/ (4 * 16 * (32 + 1)));
184 pm
= DIV_ROUND_UP(mpc8xxx_spi
->spibrg
, hz
* 4);
191 cs
->hw_mode
|= CSMODE_PM(pm
);
193 fsl_espi_change_mode(spi
);
197 static int fsl_espi_cpu_bufs(struct mpc8xxx_spi
*mspi
, struct spi_transfer
*t
,
201 struct fsl_espi_reg
*reg_base
= mspi
->reg_base
;
206 mpc8xxx_spi_write_reg(®_base
->mask
, SPIM_NE
);
209 word
= mspi
->get_tx(mspi
);
210 mpc8xxx_spi_write_reg(®_base
->transmit
, word
);
215 static int fsl_espi_bufs(struct spi_device
*spi
, struct spi_transfer
*t
)
217 struct mpc8xxx_spi
*mpc8xxx_spi
= spi_master_get_devdata(spi
->master
);
218 struct fsl_espi_reg
*reg_base
= mpc8xxx_spi
->reg_base
;
219 unsigned int len
= t
->len
;
223 bits_per_word
= spi
->bits_per_word
;
224 if (t
->bits_per_word
)
225 bits_per_word
= t
->bits_per_word
;
227 mpc8xxx_spi
->len
= t
->len
;
228 len
= roundup(len
, 4) / 4;
230 mpc8xxx_spi
->tx
= t
->tx_buf
;
231 mpc8xxx_spi
->rx
= t
->rx_buf
;
233 INIT_COMPLETION(mpc8xxx_spi
->done
);
235 /* Set SPCOM[CS] and SPCOM[TRANLEN] field */
236 if ((t
->len
- 1) > SPCOM_TRANLEN_MAX
) {
237 dev_err(mpc8xxx_spi
->dev
, "Transaction length (%d)"
238 " beyond the SPCOM[TRANLEN] field\n", t
->len
);
241 mpc8xxx_spi_write_reg(®_base
->command
,
242 (SPCOM_CS(spi
->chip_select
) | SPCOM_TRANLEN(t
->len
- 1)));
244 ret
= fsl_espi_cpu_bufs(mpc8xxx_spi
, t
, len
);
248 wait_for_completion(&mpc8xxx_spi
->done
);
250 /* disable rx ints */
251 mpc8xxx_spi_write_reg(®_base
->mask
, 0);
253 return mpc8xxx_spi
->count
;
256 static inline void fsl_espi_addr2cmd(unsigned int addr
, u8
*cmd
)
259 cmd
[1] = (u8
)(addr
>> 16);
260 cmd
[2] = (u8
)(addr
>> 8);
261 cmd
[3] = (u8
)(addr
>> 0);
265 static inline unsigned int fsl_espi_cmd2addr(u8
*cmd
)
268 return cmd
[1] << 16 | cmd
[2] << 8 | cmd
[3] << 0;
273 static void fsl_espi_do_trans(struct spi_message
*m
,
274 struct fsl_espi_transfer
*tr
)
276 struct spi_device
*spi
= m
->spi
;
277 struct mpc8xxx_spi
*mspi
= spi_master_get_devdata(spi
->master
);
278 struct fsl_espi_transfer
*espi_trans
= tr
;
279 struct spi_message message
;
280 struct spi_transfer
*t
, *first
, trans
;
283 spi_message_init(&message
);
284 memset(&trans
, 0, sizeof(trans
));
286 first
= list_first_entry(&m
->transfers
, struct spi_transfer
,
288 list_for_each_entry(t
, &m
->transfers
, transfer_list
) {
289 if ((first
->bits_per_word
!= t
->bits_per_word
) ||
290 (first
->speed_hz
!= t
->speed_hz
)) {
291 espi_trans
->status
= -EINVAL
;
292 dev_err(mspi
->dev
, "bits_per_word/speed_hz should be"
293 " same for the same SPI transfer\n");
297 trans
.speed_hz
= t
->speed_hz
;
298 trans
.bits_per_word
= t
->bits_per_word
;
299 trans
.delay_usecs
= max(first
->delay_usecs
, t
->delay_usecs
);
302 trans
.len
= espi_trans
->len
;
303 trans
.tx_buf
= espi_trans
->tx_buf
;
304 trans
.rx_buf
= espi_trans
->rx_buf
;
305 spi_message_add_tail(&trans
, &message
);
307 list_for_each_entry(t
, &message
.transfers
, transfer_list
) {
308 if (t
->bits_per_word
|| t
->speed_hz
) {
311 status
= fsl_espi_setup_transfer(spi
, t
);
317 status
= fsl_espi_bufs(spi
, t
);
325 udelay(t
->delay_usecs
);
328 espi_trans
->status
= status
;
329 fsl_espi_setup_transfer(spi
, NULL
);
332 static void fsl_espi_cmd_trans(struct spi_message
*m
,
333 struct fsl_espi_transfer
*trans
, u8
*rx_buff
)
335 struct spi_transfer
*t
;
338 struct fsl_espi_transfer
*espi_trans
= trans
;
340 local_buf
= kzalloc(SPCOM_TRANLEN_MAX
, GFP_KERNEL
);
342 espi_trans
->status
= -ENOMEM
;
346 list_for_each_entry(t
, &m
->transfers
, transfer_list
) {
348 memcpy(local_buf
+ i
, t
->tx_buf
, t
->len
);
353 espi_trans
->tx_buf
= local_buf
;
354 espi_trans
->rx_buf
= local_buf
+ espi_trans
->n_tx
;
355 fsl_espi_do_trans(m
, espi_trans
);
357 espi_trans
->actual_length
= espi_trans
->len
;
361 static void fsl_espi_rw_trans(struct spi_message
*m
,
362 struct fsl_espi_transfer
*trans
, u8
*rx_buff
)
364 struct fsl_espi_transfer
*espi_trans
= trans
;
365 unsigned int n_tx
= espi_trans
->n_tx
;
366 unsigned int n_rx
= espi_trans
->n_rx
;
367 struct spi_transfer
*t
;
369 u8
*rx_buf
= rx_buff
;
370 unsigned int trans_len
;
374 local_buf
= kzalloc(SPCOM_TRANLEN_MAX
, GFP_KERNEL
);
376 espi_trans
->status
= -ENOMEM
;
380 for (pos
= 0, loop
= 0; pos
< n_rx
; pos
+= trans_len
, loop
++) {
381 trans_len
= n_rx
- pos
;
382 if (trans_len
> SPCOM_TRANLEN_MAX
- n_tx
)
383 trans_len
= SPCOM_TRANLEN_MAX
- n_tx
;
386 list_for_each_entry(t
, &m
->transfers
, transfer_list
) {
388 memcpy(local_buf
+ i
, t
->tx_buf
, t
->len
);
394 addr
= fsl_espi_cmd2addr(local_buf
);
396 fsl_espi_addr2cmd(addr
, local_buf
);
399 espi_trans
->n_tx
= n_tx
;
400 espi_trans
->n_rx
= trans_len
;
401 espi_trans
->len
= trans_len
+ n_tx
;
402 espi_trans
->tx_buf
= local_buf
;
403 espi_trans
->rx_buf
= local_buf
+ n_tx
;
404 fsl_espi_do_trans(m
, espi_trans
);
406 memcpy(rx_buf
+ pos
, espi_trans
->rx_buf
+ n_tx
, trans_len
);
409 espi_trans
->actual_length
+= espi_trans
->len
- n_tx
;
411 espi_trans
->actual_length
+= espi_trans
->len
;
417 static void fsl_espi_do_one_msg(struct spi_message
*m
)
419 struct spi_transfer
*t
;
421 unsigned int n_tx
= 0;
422 unsigned int n_rx
= 0;
423 struct fsl_espi_transfer espi_trans
;
425 list_for_each_entry(t
, &m
->transfers
, transfer_list
) {
434 espi_trans
.n_tx
= n_tx
;
435 espi_trans
.n_rx
= n_rx
;
436 espi_trans
.len
= n_tx
+ n_rx
;
437 espi_trans
.actual_length
= 0;
438 espi_trans
.status
= 0;
441 fsl_espi_cmd_trans(m
, &espi_trans
, NULL
);
443 fsl_espi_rw_trans(m
, &espi_trans
, rx_buf
);
445 m
->actual_length
= espi_trans
.actual_length
;
446 m
->status
= espi_trans
.status
;
447 m
->complete(m
->context
);
450 static int fsl_espi_setup(struct spi_device
*spi
)
452 struct mpc8xxx_spi
*mpc8xxx_spi
;
453 struct fsl_espi_reg
*reg_base
;
457 struct spi_mpc8xxx_cs
*cs
= spi
->controller_state
;
459 if (!spi
->max_speed_hz
)
463 cs
= kzalloc(sizeof *cs
, GFP_KERNEL
);
466 spi
->controller_state
= cs
;
469 mpc8xxx_spi
= spi_master_get_devdata(spi
->master
);
470 reg_base
= mpc8xxx_spi
->reg_base
;
472 hw_mode
= cs
->hw_mode
; /* Save original settings */
473 cs
->hw_mode
= mpc8xxx_spi_read_reg(
474 ®_base
->csmode
[spi
->chip_select
]);
475 /* mask out bits we are going to set */
476 cs
->hw_mode
&= ~(CSMODE_CP_BEGIN_EDGECLK
| CSMODE_CI_INACTIVEHIGH
479 if (spi
->mode
& SPI_CPHA
)
480 cs
->hw_mode
|= CSMODE_CP_BEGIN_EDGECLK
;
481 if (spi
->mode
& SPI_CPOL
)
482 cs
->hw_mode
|= CSMODE_CI_INACTIVEHIGH
;
483 if (!(spi
->mode
& SPI_LSB_FIRST
))
484 cs
->hw_mode
|= CSMODE_REV
;
486 /* Handle the loop mode */
487 loop_mode
= mpc8xxx_spi_read_reg(®_base
->mode
);
488 loop_mode
&= ~SPMODE_LOOP
;
489 if (spi
->mode
& SPI_LOOP
)
490 loop_mode
|= SPMODE_LOOP
;
491 mpc8xxx_spi_write_reg(®_base
->mode
, loop_mode
);
493 retval
= fsl_espi_setup_transfer(spi
, NULL
);
495 cs
->hw_mode
= hw_mode
; /* Restore settings */
501 void fsl_espi_cpu_irq(struct mpc8xxx_spi
*mspi
, u32 events
)
503 struct fsl_espi_reg
*reg_base
= mspi
->reg_base
;
505 /* We need handle RX first */
506 if (events
& SPIE_NE
) {
510 /* Spin until RX is done */
511 while (SPIE_RXCNT(events
) < min(4, mspi
->len
)) {
513 events
= mpc8xxx_spi_read_reg(®_base
->event
);
516 if (mspi
->len
>= 4) {
517 rx_data
= mpc8xxx_spi_read_reg(®_base
->receive
);
522 rx_data_8
= in_8((u8
*)®_base
->receive
);
523 rx_data
|= (rx_data_8
<< (tmp
* 8));
526 rx_data
<<= (4 - mspi
->len
) * 8;
532 mspi
->get_rx(rx_data
, mspi
);
535 if (!(events
& SPIE_NF
)) {
538 /* spin until TX is done */
539 ret
= spin_event_timeout(((events
= mpc8xxx_spi_read_reg(
540 ®_base
->event
)) & SPIE_NF
) == 0, 1000, 0);
542 dev_err(mspi
->dev
, "tired waiting for SPIE_NF\n");
547 /* Clear the events */
548 mpc8xxx_spi_write_reg(®_base
->event
, events
);
552 u32 word
= mspi
->get_tx(mspi
);
554 mpc8xxx_spi_write_reg(®_base
->transmit
, word
);
556 complete(&mspi
->done
);
560 static irqreturn_t
fsl_espi_irq(s32 irq
, void *context_data
)
562 struct mpc8xxx_spi
*mspi
= context_data
;
563 struct fsl_espi_reg
*reg_base
= mspi
->reg_base
;
564 irqreturn_t ret
= IRQ_NONE
;
567 /* Get interrupt events(tx/rx) */
568 events
= mpc8xxx_spi_read_reg(®_base
->event
);
572 dev_vdbg(mspi
->dev
, "%s: events %x\n", __func__
, events
);
574 fsl_espi_cpu_irq(mspi
, events
);
579 static void fsl_espi_remove(struct mpc8xxx_spi
*mspi
)
581 iounmap(mspi
->reg_base
);
584 static struct spi_master
* fsl_espi_probe(struct device
*dev
,
585 struct resource
*mem
, unsigned int irq
)
587 struct fsl_spi_platform_data
*pdata
= dev_get_platdata(dev
);
588 struct spi_master
*master
;
589 struct mpc8xxx_spi
*mpc8xxx_spi
;
590 struct fsl_espi_reg
*reg_base
;
594 master
= spi_alloc_master(dev
, sizeof(struct mpc8xxx_spi
));
600 dev_set_drvdata(dev
, master
);
602 ret
= mpc8xxx_spi_probe(dev
, mem
, irq
);
606 master
->bits_per_word_mask
= SPI_BPW_RANGE_MASK(4, 16);
607 master
->setup
= fsl_espi_setup
;
609 mpc8xxx_spi
= spi_master_get_devdata(master
);
610 mpc8xxx_spi
->spi_do_one_msg
= fsl_espi_do_one_msg
;
611 mpc8xxx_spi
->spi_remove
= fsl_espi_remove
;
613 mpc8xxx_spi
->reg_base
= ioremap(mem
->start
, resource_size(mem
));
614 if (!mpc8xxx_spi
->reg_base
) {
619 reg_base
= mpc8xxx_spi
->reg_base
;
621 /* Register for SPI Interrupt */
622 ret
= request_irq(mpc8xxx_spi
->irq
, fsl_espi_irq
,
623 0, "fsl_espi", mpc8xxx_spi
);
627 if (mpc8xxx_spi
->flags
& SPI_QE_CPU_MODE
) {
628 mpc8xxx_spi
->rx_shift
= 16;
629 mpc8xxx_spi
->tx_shift
= 24;
632 /* SPI controller initializations */
633 mpc8xxx_spi_write_reg(®_base
->mode
, 0);
634 mpc8xxx_spi_write_reg(®_base
->mask
, 0);
635 mpc8xxx_spi_write_reg(®_base
->command
, 0);
636 mpc8xxx_spi_write_reg(®_base
->event
, 0xffffffff);
638 /* Init eSPI CS mode register */
639 for (i
= 0; i
< pdata
->max_chipselect
; i
++)
640 mpc8xxx_spi_write_reg(®_base
->csmode
[i
], CSMODE_INIT_VAL
);
642 /* Enable SPI interface */
643 regval
= pdata
->initial_spmode
| SPMODE_INIT_VAL
| SPMODE_ENABLE
;
645 mpc8xxx_spi_write_reg(®_base
->mode
, regval
);
647 ret
= spi_register_master(master
);
651 dev_info(dev
, "at 0x%p (irq = %d)\n", reg_base
, mpc8xxx_spi
->irq
);
656 free_irq(mpc8xxx_spi
->irq
, mpc8xxx_spi
);
658 iounmap(mpc8xxx_spi
->reg_base
);
660 spi_master_put(master
);
665 static int of_fsl_espi_get_chipselects(struct device
*dev
)
667 struct device_node
*np
= dev
->of_node
;
668 struct fsl_spi_platform_data
*pdata
= dev_get_platdata(dev
);
672 prop
= of_get_property(np
, "fsl,espi-num-chipselects", &len
);
673 if (!prop
|| len
< sizeof(*prop
)) {
674 dev_err(dev
, "No 'fsl,espi-num-chipselects' property\n");
678 pdata
->max_chipselect
= *prop
;
679 pdata
->cs_control
= NULL
;
684 static int of_fsl_espi_probe(struct platform_device
*ofdev
)
686 struct device
*dev
= &ofdev
->dev
;
687 struct device_node
*np
= ofdev
->dev
.of_node
;
688 struct spi_master
*master
;
693 ret
= of_mpc8xxx_spi_probe(ofdev
);
697 ret
= of_fsl_espi_get_chipselects(dev
);
701 ret
= of_address_to_resource(np
, 0, &mem
);
705 ret
= of_irq_to_resource(np
, 0, &irq
);
711 master
= fsl_espi_probe(dev
, &mem
, irq
.start
);
712 if (IS_ERR(master
)) {
713 ret
= PTR_ERR(master
);
723 static int of_fsl_espi_remove(struct platform_device
*dev
)
725 return mpc8xxx_spi_remove(&dev
->dev
);
728 static const struct of_device_id of_fsl_espi_match
[] = {
729 { .compatible
= "fsl,mpc8536-espi" },
732 MODULE_DEVICE_TABLE(of
, of_fsl_espi_match
);
734 static struct platform_driver fsl_espi_driver
= {
737 .owner
= THIS_MODULE
,
738 .of_match_table
= of_fsl_espi_match
,
740 .probe
= of_fsl_espi_probe
,
741 .remove
= of_fsl_espi_remove
,
743 module_platform_driver(fsl_espi_driver
);
745 MODULE_AUTHOR("Mingkai Hu");
746 MODULE_DESCRIPTION("Enhanced Freescale SPI Driver");
747 MODULE_LICENSE("GPL");