2 * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
3 * Copyright (C) 2008 Juergen Beisert
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version 2
8 * of the License, or (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the
16 * Free Software Foundation
17 * 51 Franklin Street, Fifth Floor
18 * Boston, MA 02110-1301, USA.
21 #include <linux/clk.h>
22 #include <linux/completion.h>
23 #include <linux/delay.h>
24 #include <linux/err.h>
25 #include <linux/gpio.h>
26 #include <linux/init.h>
27 #include <linux/interrupt.h>
29 #include <linux/irq.h>
30 #include <linux/kernel.h>
31 #include <linux/module.h>
32 #include <linux/platform_device.h>
33 #include <linux/slab.h>
34 #include <linux/spi/spi.h>
35 #include <linux/spi/spi_bitbang.h>
36 #include <linux/types.h>
40 #define DRIVER_NAME "spi_imx"
42 #define MXC_CSPIRXDATA 0x00
43 #define MXC_CSPITXDATA 0x04
44 #define MXC_CSPICTRL 0x08
45 #define MXC_CSPIINT 0x0c
46 #define MXC_RESET 0x1c
48 #define MX3_CSPISTAT 0x14
49 #define MX3_CSPISTAT_RR (1 << 3)
51 /* generic defines to abstract from the different register layouts */
52 #define MXC_INT_RR (1 << 0) /* Receive data ready interrupt */
53 #define MXC_INT_TE (1 << 1) /* Transmit FIFO empty interrupt */
55 struct spi_imx_config
{
56 unsigned int speed_hz
;
63 struct spi_bitbang bitbang
;
65 struct completion xfer_done
;
69 unsigned long spi_clk
;
73 void (*tx
)(struct spi_imx_data
*);
74 void (*rx
)(struct spi_imx_data
*);
77 unsigned int txfifo
; /* number of words pushed in tx FIFO */
79 /* SoC specific functions */
80 void (*intctrl
)(struct spi_imx_data
*, int);
81 int (*config
)(struct spi_imx_data
*, struct spi_imx_config
*);
82 void (*trigger
)(struct spi_imx_data
*);
83 int (*rx_available
)(struct spi_imx_data
*);
86 #define MXC_SPI_BUF_RX(type) \
87 static void spi_imx_buf_rx_##type(struct spi_imx_data *spi_imx) \
89 unsigned int val = readl(spi_imx->base + MXC_CSPIRXDATA); \
91 if (spi_imx->rx_buf) { \
92 *(type *)spi_imx->rx_buf = val; \
93 spi_imx->rx_buf += sizeof(type); \
97 #define MXC_SPI_BUF_TX(type) \
98 static void spi_imx_buf_tx_##type(struct spi_imx_data *spi_imx) \
102 if (spi_imx->tx_buf) { \
103 val = *(type *)spi_imx->tx_buf; \
104 spi_imx->tx_buf += sizeof(type); \
107 spi_imx->count -= sizeof(type); \
109 writel(val, spi_imx->base + MXC_CSPITXDATA); \
119 /* First entry is reserved, second entry is valid only if SDHC_SPIEN is set
120 * (which is currently not the case in this driver)
122 static int mxc_clkdivs
[] = {0, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, 128, 192,
123 256, 384, 512, 768, 1024};
126 static unsigned int spi_imx_clkdiv_1(unsigned int fin
,
136 for (i
= 2; i
< max
; i
++)
137 if (fspi
* mxc_clkdivs
[i
] >= fin
)
143 /* MX1, MX31, MX35 */
144 static unsigned int spi_imx_clkdiv_2(unsigned int fin
,
149 for (i
= 0; i
< 7; i
++) {
150 if (fspi
* div
>= fin
)
158 #define MX31_INTREG_TEEN (1 << 0)
159 #define MX31_INTREG_RREN (1 << 3)
161 #define MX31_CSPICTRL_ENABLE (1 << 0)
162 #define MX31_CSPICTRL_MASTER (1 << 1)
163 #define MX31_CSPICTRL_XCH (1 << 2)
164 #define MX31_CSPICTRL_POL (1 << 4)
165 #define MX31_CSPICTRL_PHA (1 << 5)
166 #define MX31_CSPICTRL_SSCTL (1 << 6)
167 #define MX31_CSPICTRL_SSPOL (1 << 7)
168 #define MX31_CSPICTRL_BC_SHIFT 8
169 #define MX35_CSPICTRL_BL_SHIFT 20
170 #define MX31_CSPICTRL_CS_SHIFT 24
171 #define MX35_CSPICTRL_CS_SHIFT 12
172 #define MX31_CSPICTRL_DR_SHIFT 16
174 #define MX31_CSPISTATUS 0x14
175 #define MX31_STATUS_RR (1 << 3)
177 /* These functions also work for the i.MX35, but be aware that
178 * the i.MX35 has a slightly different register layout for bits
179 * we do not use here.
181 static void mx31_intctrl(struct spi_imx_data
*spi_imx
, int enable
)
183 unsigned int val
= 0;
185 if (enable
& MXC_INT_TE
)
186 val
|= MX31_INTREG_TEEN
;
187 if (enable
& MXC_INT_RR
)
188 val
|= MX31_INTREG_RREN
;
190 writel(val
, spi_imx
->base
+ MXC_CSPIINT
);
193 static void mx31_trigger(struct spi_imx_data
*spi_imx
)
197 reg
= readl(spi_imx
->base
+ MXC_CSPICTRL
);
198 reg
|= MX31_CSPICTRL_XCH
;
199 writel(reg
, spi_imx
->base
+ MXC_CSPICTRL
);
202 static int mx31_config(struct spi_imx_data
*spi_imx
,
203 struct spi_imx_config
*config
)
205 unsigned int reg
= MX31_CSPICTRL_ENABLE
| MX31_CSPICTRL_MASTER
;
207 reg
|= spi_imx_clkdiv_2(spi_imx
->spi_clk
, config
->speed_hz
) <<
208 MX31_CSPICTRL_DR_SHIFT
;
211 reg
|= (config
->bpw
- 1) << MX31_CSPICTRL_BC_SHIFT
;
212 else if (cpu_is_mx25() || cpu_is_mx35()) {
213 reg
|= (config
->bpw
- 1) << MX35_CSPICTRL_BL_SHIFT
;
214 reg
|= MX31_CSPICTRL_SSCTL
;
217 if (config
->mode
& SPI_CPHA
)
218 reg
|= MX31_CSPICTRL_PHA
;
219 if (config
->mode
& SPI_CPOL
)
220 reg
|= MX31_CSPICTRL_POL
;
221 if (config
->mode
& SPI_CS_HIGH
)
222 reg
|= MX31_CSPICTRL_SSPOL
;
223 if (config
->cs
< 0) {
225 reg
|= (config
->cs
+ 32) << MX31_CSPICTRL_CS_SHIFT
;
226 else if (cpu_is_mx25() || cpu_is_mx35())
227 reg
|= (config
->cs
+ 32) << MX35_CSPICTRL_CS_SHIFT
;
230 writel(reg
, spi_imx
->base
+ MXC_CSPICTRL
);
235 static int mx31_rx_available(struct spi_imx_data
*spi_imx
)
237 return readl(spi_imx
->base
+ MX31_CSPISTATUS
) & MX31_STATUS_RR
;
240 #define MX27_INTREG_RR (1 << 4)
241 #define MX27_INTREG_TEEN (1 << 9)
242 #define MX27_INTREG_RREN (1 << 13)
244 #define MX27_CSPICTRL_POL (1 << 5)
245 #define MX27_CSPICTRL_PHA (1 << 6)
246 #define MX27_CSPICTRL_SSPOL (1 << 8)
247 #define MX27_CSPICTRL_XCH (1 << 9)
248 #define MX27_CSPICTRL_ENABLE (1 << 10)
249 #define MX27_CSPICTRL_MASTER (1 << 11)
250 #define MX27_CSPICTRL_DR_SHIFT 14
251 #define MX27_CSPICTRL_CS_SHIFT 19
253 static void mx27_intctrl(struct spi_imx_data
*spi_imx
, int enable
)
255 unsigned int val
= 0;
257 if (enable
& MXC_INT_TE
)
258 val
|= MX27_INTREG_TEEN
;
259 if (enable
& MXC_INT_RR
)
260 val
|= MX27_INTREG_RREN
;
262 writel(val
, spi_imx
->base
+ MXC_CSPIINT
);
265 static void mx27_trigger(struct spi_imx_data
*spi_imx
)
269 reg
= readl(spi_imx
->base
+ MXC_CSPICTRL
);
270 reg
|= MX27_CSPICTRL_XCH
;
271 writel(reg
, spi_imx
->base
+ MXC_CSPICTRL
);
274 static int mx27_config(struct spi_imx_data
*spi_imx
,
275 struct spi_imx_config
*config
)
277 unsigned int reg
= MX27_CSPICTRL_ENABLE
| MX27_CSPICTRL_MASTER
;
279 reg
|= spi_imx_clkdiv_1(spi_imx
->spi_clk
, config
->speed_hz
) <<
280 MX27_CSPICTRL_DR_SHIFT
;
281 reg
|= config
->bpw
- 1;
283 if (config
->mode
& SPI_CPHA
)
284 reg
|= MX27_CSPICTRL_PHA
;
285 if (config
->mode
& SPI_CPOL
)
286 reg
|= MX27_CSPICTRL_POL
;
287 if (config
->mode
& SPI_CS_HIGH
)
288 reg
|= MX27_CSPICTRL_SSPOL
;
290 reg
|= (config
->cs
+ 32) << MX27_CSPICTRL_CS_SHIFT
;
292 writel(reg
, spi_imx
->base
+ MXC_CSPICTRL
);
297 static int mx27_rx_available(struct spi_imx_data
*spi_imx
)
299 return readl(spi_imx
->base
+ MXC_CSPIINT
) & MX27_INTREG_RR
;
302 #define MX1_INTREG_RR (1 << 3)
303 #define MX1_INTREG_TEEN (1 << 8)
304 #define MX1_INTREG_RREN (1 << 11)
306 #define MX1_CSPICTRL_POL (1 << 4)
307 #define MX1_CSPICTRL_PHA (1 << 5)
308 #define MX1_CSPICTRL_XCH (1 << 8)
309 #define MX1_CSPICTRL_ENABLE (1 << 9)
310 #define MX1_CSPICTRL_MASTER (1 << 10)
311 #define MX1_CSPICTRL_DR_SHIFT 13
313 static void mx1_intctrl(struct spi_imx_data
*spi_imx
, int enable
)
315 unsigned int val
= 0;
317 if (enable
& MXC_INT_TE
)
318 val
|= MX1_INTREG_TEEN
;
319 if (enable
& MXC_INT_RR
)
320 val
|= MX1_INTREG_RREN
;
322 writel(val
, spi_imx
->base
+ MXC_CSPIINT
);
325 static void mx1_trigger(struct spi_imx_data
*spi_imx
)
329 reg
= readl(spi_imx
->base
+ MXC_CSPICTRL
);
330 reg
|= MX1_CSPICTRL_XCH
;
331 writel(reg
, spi_imx
->base
+ MXC_CSPICTRL
);
334 static int mx1_config(struct spi_imx_data
*spi_imx
,
335 struct spi_imx_config
*config
)
337 unsigned int reg
= MX1_CSPICTRL_ENABLE
| MX1_CSPICTRL_MASTER
;
339 reg
|= spi_imx_clkdiv_2(spi_imx
->spi_clk
, config
->speed_hz
) <<
340 MX1_CSPICTRL_DR_SHIFT
;
341 reg
|= config
->bpw
- 1;
343 if (config
->mode
& SPI_CPHA
)
344 reg
|= MX1_CSPICTRL_PHA
;
345 if (config
->mode
& SPI_CPOL
)
346 reg
|= MX1_CSPICTRL_POL
;
348 writel(reg
, spi_imx
->base
+ MXC_CSPICTRL
);
353 static int mx1_rx_available(struct spi_imx_data
*spi_imx
)
355 return readl(spi_imx
->base
+ MXC_CSPIINT
) & MX1_INTREG_RR
;
358 static void spi_imx_chipselect(struct spi_device
*spi
, int is_active
)
360 struct spi_imx_data
*spi_imx
= spi_master_get_devdata(spi
->master
);
361 int gpio
= spi_imx
->chipselect
[spi
->chip_select
];
362 int active
= is_active
!= BITBANG_CS_INACTIVE
;
363 int dev_is_lowactive
= !(spi
->mode
& SPI_CS_HIGH
);
368 gpio_set_value(gpio
, dev_is_lowactive
^ active
);
371 static void spi_imx_push(struct spi_imx_data
*spi_imx
)
373 while (spi_imx
->txfifo
< 8) {
376 spi_imx
->tx(spi_imx
);
380 spi_imx
->trigger(spi_imx
);
383 static irqreturn_t
spi_imx_isr(int irq
, void *dev_id
)
385 struct spi_imx_data
*spi_imx
= dev_id
;
387 while (spi_imx
->rx_available(spi_imx
)) {
388 spi_imx
->rx(spi_imx
);
392 if (spi_imx
->count
) {
393 spi_imx_push(spi_imx
);
397 if (spi_imx
->txfifo
) {
398 /* No data left to push, but still waiting for rx data,
399 * enable receive data available interrupt.
401 spi_imx
->intctrl(spi_imx
, MXC_INT_RR
);
405 spi_imx
->intctrl(spi_imx
, 0);
406 complete(&spi_imx
->xfer_done
);
411 static int spi_imx_setupxfer(struct spi_device
*spi
,
412 struct spi_transfer
*t
)
414 struct spi_imx_data
*spi_imx
= spi_master_get_devdata(spi
->master
);
415 struct spi_imx_config config
;
417 config
.bpw
= t
? t
->bits_per_word
: spi
->bits_per_word
;
418 config
.speed_hz
= t
? t
->speed_hz
: spi
->max_speed_hz
;
419 config
.mode
= spi
->mode
;
420 config
.cs
= spi_imx
->chipselect
[spi
->chip_select
];
422 if (!config
.speed_hz
)
423 config
.speed_hz
= spi
->max_speed_hz
;
425 config
.bpw
= spi
->bits_per_word
;
426 if (!config
.speed_hz
)
427 config
.speed_hz
= spi
->max_speed_hz
;
429 /* Initialize the functions for transfer */
430 if (config
.bpw
<= 8) {
431 spi_imx
->rx
= spi_imx_buf_rx_u8
;
432 spi_imx
->tx
= spi_imx_buf_tx_u8
;
433 } else if (config
.bpw
<= 16) {
434 spi_imx
->rx
= spi_imx_buf_rx_u16
;
435 spi_imx
->tx
= spi_imx_buf_tx_u16
;
436 } else if (config
.bpw
<= 32) {
437 spi_imx
->rx
= spi_imx_buf_rx_u32
;
438 spi_imx
->tx
= spi_imx_buf_tx_u32
;
442 spi_imx
->config(spi_imx
, &config
);
447 static int spi_imx_transfer(struct spi_device
*spi
,
448 struct spi_transfer
*transfer
)
450 struct spi_imx_data
*spi_imx
= spi_master_get_devdata(spi
->master
);
452 spi_imx
->tx_buf
= transfer
->tx_buf
;
453 spi_imx
->rx_buf
= transfer
->rx_buf
;
454 spi_imx
->count
= transfer
->len
;
457 init_completion(&spi_imx
->xfer_done
);
459 spi_imx_push(spi_imx
);
461 spi_imx
->intctrl(spi_imx
, MXC_INT_TE
);
463 wait_for_completion(&spi_imx
->xfer_done
);
465 return transfer
->len
;
468 static int spi_imx_setup(struct spi_device
*spi
)
470 struct spi_imx_data
*spi_imx
= spi_master_get_devdata(spi
->master
);
471 int gpio
= spi_imx
->chipselect
[spi
->chip_select
];
473 dev_dbg(&spi
->dev
, "%s: mode %d, %u bpw, %d hz\n", __func__
,
474 spi
->mode
, spi
->bits_per_word
, spi
->max_speed_hz
);
477 gpio_direction_output(gpio
, spi
->mode
& SPI_CS_HIGH
? 0 : 1);
479 spi_imx_chipselect(spi
, BITBANG_CS_INACTIVE
);
484 static void spi_imx_cleanup(struct spi_device
*spi
)
488 static int __devinit
spi_imx_probe(struct platform_device
*pdev
)
490 struct spi_imx_master
*mxc_platform_info
;
491 struct spi_master
*master
;
492 struct spi_imx_data
*spi_imx
;
493 struct resource
*res
;
496 mxc_platform_info
= dev_get_platdata(&pdev
->dev
);
497 if (!mxc_platform_info
) {
498 dev_err(&pdev
->dev
, "can't get the platform data\n");
502 master
= spi_alloc_master(&pdev
->dev
, sizeof(struct spi_imx_data
));
506 platform_set_drvdata(pdev
, master
);
508 master
->bus_num
= pdev
->id
;
509 master
->num_chipselect
= mxc_platform_info
->num_chipselect
;
511 spi_imx
= spi_master_get_devdata(master
);
512 spi_imx
->bitbang
.master
= spi_master_get(master
);
513 spi_imx
->chipselect
= mxc_platform_info
->chipselect
;
515 for (i
= 0; i
< master
->num_chipselect
; i
++) {
516 if (spi_imx
->chipselect
[i
] < 0)
518 ret
= gpio_request(spi_imx
->chipselect
[i
], DRIVER_NAME
);
522 if (spi_imx
->chipselect
[i
] >= 0)
523 gpio_free(spi_imx
->chipselect
[i
]);
525 dev_err(&pdev
->dev
, "can't get cs gpios\n");
530 spi_imx
->bitbang
.chipselect
= spi_imx_chipselect
;
531 spi_imx
->bitbang
.setup_transfer
= spi_imx_setupxfer
;
532 spi_imx
->bitbang
.txrx_bufs
= spi_imx_transfer
;
533 spi_imx
->bitbang
.master
->setup
= spi_imx_setup
;
534 spi_imx
->bitbang
.master
->cleanup
= spi_imx_cleanup
;
535 spi_imx
->bitbang
.master
->mode_bits
= SPI_CPOL
| SPI_CPHA
| SPI_CS_HIGH
;
537 init_completion(&spi_imx
->xfer_done
);
539 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
541 dev_err(&pdev
->dev
, "can't get platform resource\n");
546 if (!request_mem_region(res
->start
, resource_size(res
), pdev
->name
)) {
547 dev_err(&pdev
->dev
, "request_mem_region failed\n");
552 spi_imx
->base
= ioremap(res
->start
, resource_size(res
));
553 if (!spi_imx
->base
) {
555 goto out_release_mem
;
558 spi_imx
->irq
= platform_get_irq(pdev
, 0);
559 if (spi_imx
->irq
<= 0) {
564 ret
= request_irq(spi_imx
->irq
, spi_imx_isr
, 0, DRIVER_NAME
, spi_imx
);
566 dev_err(&pdev
->dev
, "can't get irq%d: %d\n", spi_imx
->irq
, ret
);
570 if (cpu_is_mx25() || cpu_is_mx31() || cpu_is_mx35()) {
571 spi_imx
->intctrl
= mx31_intctrl
;
572 spi_imx
->config
= mx31_config
;
573 spi_imx
->trigger
= mx31_trigger
;
574 spi_imx
->rx_available
= mx31_rx_available
;
575 } else if (cpu_is_mx27() || cpu_is_mx21()) {
576 spi_imx
->intctrl
= mx27_intctrl
;
577 spi_imx
->config
= mx27_config
;
578 spi_imx
->trigger
= mx27_trigger
;
579 spi_imx
->rx_available
= mx27_rx_available
;
580 } else if (cpu_is_mx1()) {
581 spi_imx
->intctrl
= mx1_intctrl
;
582 spi_imx
->config
= mx1_config
;
583 spi_imx
->trigger
= mx1_trigger
;
584 spi_imx
->rx_available
= mx1_rx_available
;
588 spi_imx
->clk
= clk_get(&pdev
->dev
, NULL
);
589 if (IS_ERR(spi_imx
->clk
)) {
590 dev_err(&pdev
->dev
, "unable to get clock\n");
591 ret
= PTR_ERR(spi_imx
->clk
);
595 clk_enable(spi_imx
->clk
);
596 spi_imx
->spi_clk
= clk_get_rate(spi_imx
->clk
);
598 if (cpu_is_mx1() || cpu_is_mx21() || cpu_is_mx27())
599 writel(1, spi_imx
->base
+ MXC_RESET
);
601 /* drain receive buffer */
602 if (cpu_is_mx25() || cpu_is_mx31() || cpu_is_mx35())
603 while (readl(spi_imx
->base
+ MX3_CSPISTAT
) & MX3_CSPISTAT_RR
)
604 readl(spi_imx
->base
+ MXC_CSPIRXDATA
);
606 spi_imx
->intctrl(spi_imx
, 0);
608 ret
= spi_bitbang_start(&spi_imx
->bitbang
);
610 dev_err(&pdev
->dev
, "bitbang start failed with %d\n", ret
);
614 dev_info(&pdev
->dev
, "probed\n");
619 clk_disable(spi_imx
->clk
);
620 clk_put(spi_imx
->clk
);
622 free_irq(spi_imx
->irq
, spi_imx
);
624 iounmap(spi_imx
->base
);
626 release_mem_region(res
->start
, resource_size(res
));
628 for (i
= 0; i
< master
->num_chipselect
; i
++)
629 if (spi_imx
->chipselect
[i
] >= 0)
630 gpio_free(spi_imx
->chipselect
[i
]);
632 spi_master_put(master
);
634 platform_set_drvdata(pdev
, NULL
);
638 static int __devexit
spi_imx_remove(struct platform_device
*pdev
)
640 struct spi_master
*master
= platform_get_drvdata(pdev
);
641 struct resource
*res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
642 struct spi_imx_data
*spi_imx
= spi_master_get_devdata(master
);
645 spi_bitbang_stop(&spi_imx
->bitbang
);
647 writel(0, spi_imx
->base
+ MXC_CSPICTRL
);
648 clk_disable(spi_imx
->clk
);
649 clk_put(spi_imx
->clk
);
650 free_irq(spi_imx
->irq
, spi_imx
);
651 iounmap(spi_imx
->base
);
653 for (i
= 0; i
< master
->num_chipselect
; i
++)
654 if (spi_imx
->chipselect
[i
] >= 0)
655 gpio_free(spi_imx
->chipselect
[i
]);
657 spi_master_put(master
);
659 release_mem_region(res
->start
, resource_size(res
));
661 platform_set_drvdata(pdev
, NULL
);
666 static struct platform_driver spi_imx_driver
= {
669 .owner
= THIS_MODULE
,
671 .probe
= spi_imx_probe
,
672 .remove
= __devexit_p(spi_imx_remove
),
675 static int __init
spi_imx_init(void)
677 return platform_driver_register(&spi_imx_driver
);
680 static void __exit
spi_imx_exit(void)
682 platform_driver_unregister(&spi_imx_driver
);
685 module_init(spi_imx_init
);
686 module_exit(spi_imx_exit
);
688 MODULE_DESCRIPTION("SPI Master Controller driver");
689 MODULE_AUTHOR("Sascha Hauer, Pengutronix");
690 MODULE_LICENSE("GPL");