2 * OMAP7xx SPI 100k controller driver
3 * Author: Fabrice Crohas <fcrohas@gmail.com>
4 * from original omap1_mcspi driver
6 * Copyright (C) 2005, 2006 Nokia Corporation
7 * Author: Samuel Ortiz <samuel.ortiz@nokia.com> and
8 * Juha Yrj�l� <juha.yrjola@nokia.com>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 #include <linux/kernel.h>
26 #include <linux/init.h>
27 #include <linux/interrupt.h>
28 #include <linux/module.h>
29 #include <linux/device.h>
30 #include <linux/delay.h>
31 #include <linux/platform_device.h>
32 #include <linux/err.h>
33 #include <linux/clk.h>
35 #include <linux/gpio.h>
36 #include <linux/slab.h>
38 #include <linux/spi/spi.h>
40 #define OMAP1_SPI100K_MAX_FREQ 48000000
42 #define ICR_SPITAS (OMAP7XX_ICR_BASE + 0x12)
44 #define SPI_SETUP1 0x00
45 #define SPI_SETUP2 0x02
47 #define SPI_STATUS 0x06
48 #define SPI_TX_LSB 0x08
49 #define SPI_TX_MSB 0x0a
50 #define SPI_RX_LSB 0x0c
51 #define SPI_RX_MSB 0x0e
53 #define SPI_SETUP1_INT_READ_ENABLE (1UL << 5)
54 #define SPI_SETUP1_INT_WRITE_ENABLE (1UL << 4)
55 #define SPI_SETUP1_CLOCK_DIVISOR(x) ((x) << 1)
56 #define SPI_SETUP1_CLOCK_ENABLE (1UL << 0)
58 #define SPI_SETUP2_ACTIVE_EDGE_FALLING (0UL << 0)
59 #define SPI_SETUP2_ACTIVE_EDGE_RISING (1UL << 0)
60 #define SPI_SETUP2_NEGATIVE_LEVEL (0UL << 5)
61 #define SPI_SETUP2_POSITIVE_LEVEL (1UL << 5)
62 #define SPI_SETUP2_LEVEL_TRIGGER (0UL << 10)
63 #define SPI_SETUP2_EDGE_TRIGGER (1UL << 10)
65 #define SPI_CTRL_SEN(x) ((x) << 7)
66 #define SPI_CTRL_WORD_SIZE(x) (((x) - 1) << 2)
67 #define SPI_CTRL_WR (1UL << 1)
68 #define SPI_CTRL_RD (1UL << 0)
70 #define SPI_STATUS_WE (1UL << 1)
71 #define SPI_STATUS_RD (1UL << 0)
73 /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
74 * cache operations; better heuristics consider wordsize and bitrate.
76 #define DMA_MIN_BYTES 8
79 #define SPI_SHUTDOWN 1
81 struct omap1_spi100k
{
85 /* Virtual base address of the controller */
89 struct omap1_spi100k_cs
{
94 static void spi100k_enable_clock(struct spi_master
*master
)
97 struct omap1_spi100k
*spi100k
= spi_master_get_devdata(master
);
100 val
= readw(spi100k
->base
+ SPI_SETUP1
);
101 val
|= SPI_SETUP1_CLOCK_ENABLE
;
102 writew(val
, spi100k
->base
+ SPI_SETUP1
);
105 static void spi100k_disable_clock(struct spi_master
*master
)
108 struct omap1_spi100k
*spi100k
= spi_master_get_devdata(master
);
111 val
= readw(spi100k
->base
+ SPI_SETUP1
);
112 val
&= ~SPI_SETUP1_CLOCK_ENABLE
;
113 writew(val
, spi100k
->base
+ SPI_SETUP1
);
116 static void spi100k_write_data(struct spi_master
*master
, int len
, int data
)
118 struct omap1_spi100k
*spi100k
= spi_master_get_devdata(master
);
120 /* write 16-bit word, shifting 8-bit data if necessary */
126 spi100k_enable_clock(master
);
127 writew(data
, spi100k
->base
+ SPI_TX_MSB
);
129 writew(SPI_CTRL_SEN(0) |
130 SPI_CTRL_WORD_SIZE(len
) |
132 spi100k
->base
+ SPI_CTRL
);
134 /* Wait for bit ack send change */
135 while ((readw(spi100k
->base
+ SPI_STATUS
) & SPI_STATUS_WE
) != SPI_STATUS_WE
)
139 spi100k_disable_clock(master
);
142 static int spi100k_read_data(struct spi_master
*master
, int len
)
145 struct omap1_spi100k
*spi100k
= spi_master_get_devdata(master
);
147 /* Always do at least 16 bits */
151 spi100k_enable_clock(master
);
152 writew(SPI_CTRL_SEN(0) |
153 SPI_CTRL_WORD_SIZE(len
) |
155 spi100k
->base
+ SPI_CTRL
);
157 while ((readw(spi100k
->base
+ SPI_STATUS
) & SPI_STATUS_RD
) != SPI_STATUS_RD
)
161 dataL
= readw(spi100k
->base
+ SPI_RX_LSB
);
162 dataH
= readw(spi100k
->base
+ SPI_RX_MSB
);
163 spi100k_disable_clock(master
);
168 static void spi100k_open(struct spi_master
*master
)
170 /* get control of SPI */
171 struct omap1_spi100k
*spi100k
= spi_master_get_devdata(master
);
173 writew(SPI_SETUP1_INT_READ_ENABLE
|
174 SPI_SETUP1_INT_WRITE_ENABLE
|
175 SPI_SETUP1_CLOCK_DIVISOR(0), spi100k
->base
+ SPI_SETUP1
);
177 /* configure clock and interrupts */
178 writew(SPI_SETUP2_ACTIVE_EDGE_FALLING
|
179 SPI_SETUP2_NEGATIVE_LEVEL
|
180 SPI_SETUP2_LEVEL_TRIGGER
, spi100k
->base
+ SPI_SETUP2
);
183 static void omap1_spi100k_force_cs(struct omap1_spi100k
*spi100k
, int enable
)
186 writew(0x05fc, spi100k
->base
+ SPI_CTRL
);
188 writew(0x05fd, spi100k
->base
+ SPI_CTRL
);
192 omap1_spi100k_txrx_pio(struct spi_device
*spi
, struct spi_transfer
*xfer
)
194 struct omap1_spi100k_cs
*cs
= spi
->controller_state
;
195 unsigned int count
, c
;
200 word_len
= cs
->word_len
;
210 if (xfer
->tx_buf
!= NULL
)
211 spi100k_write_data(spi
->master
, word_len
, *tx
++);
212 if (xfer
->rx_buf
!= NULL
)
213 *rx
++ = spi100k_read_data(spi
->master
, word_len
);
215 } else if (word_len
<= 16) {
223 if (xfer
->tx_buf
!= NULL
)
224 spi100k_write_data(spi
->master
, word_len
, *tx
++);
225 if (xfer
->rx_buf
!= NULL
)
226 *rx
++ = spi100k_read_data(spi
->master
, word_len
);
228 } else if (word_len
<= 32) {
236 if (xfer
->tx_buf
!= NULL
)
237 spi100k_write_data(spi
->master
, word_len
, *tx
);
238 if (xfer
->rx_buf
!= NULL
)
239 *rx
= spi100k_read_data(spi
->master
, word_len
);
245 /* called only when no transfer is active to this device */
246 static int omap1_spi100k_setup_transfer(struct spi_device
*spi
,
247 struct spi_transfer
*t
)
249 struct omap1_spi100k
*spi100k
= spi_master_get_devdata(spi
->master
);
250 struct omap1_spi100k_cs
*cs
= spi
->controller_state
;
251 u8 word_len
= spi
->bits_per_word
;
253 if (t
!= NULL
&& t
->bits_per_word
)
254 word_len
= t
->bits_per_word
;
258 if (spi
->bits_per_word
> 32)
260 cs
->word_len
= word_len
;
262 /* SPI init before transfer */
263 writew(0x3e , spi100k
->base
+ SPI_SETUP1
);
264 writew(0x00 , spi100k
->base
+ SPI_STATUS
);
265 writew(0x3e , spi100k
->base
+ SPI_CTRL
);
270 /* the spi->mode bits understood by this driver: */
271 #define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
273 static int omap1_spi100k_setup(struct spi_device
*spi
)
276 struct omap1_spi100k
*spi100k
;
277 struct omap1_spi100k_cs
*cs
= spi
->controller_state
;
279 spi100k
= spi_master_get_devdata(spi
->master
);
282 cs
= devm_kzalloc(&spi
->dev
, sizeof(*cs
), GFP_KERNEL
);
285 cs
->base
= spi100k
->base
+ spi
->chip_select
* 0x14;
286 spi
->controller_state
= cs
;
289 spi100k_open(spi
->master
);
291 clk_prepare_enable(spi100k
->ick
);
292 clk_prepare_enable(spi100k
->fck
);
294 ret
= omap1_spi100k_setup_transfer(spi
, NULL
);
296 clk_disable_unprepare(spi100k
->ick
);
297 clk_disable_unprepare(spi100k
->fck
);
302 static int omap1_spi100k_prepare_hardware(struct spi_master
*master
)
304 struct omap1_spi100k
*spi100k
= spi_master_get_devdata(master
);
306 clk_prepare_enable(spi100k
->ick
);
307 clk_prepare_enable(spi100k
->fck
);
312 static int omap1_spi100k_transfer_one_message(struct spi_master
*master
,
313 struct spi_message
*m
)
315 struct omap1_spi100k
*spi100k
= spi_master_get_devdata(master
);
316 struct spi_device
*spi
= m
->spi
;
317 struct spi_transfer
*t
= NULL
;
319 int par_override
= 0;
322 list_for_each_entry(t
, &m
->transfers
, transfer_list
) {
323 if (t
->tx_buf
== NULL
&& t
->rx_buf
== NULL
&& t
->len
) {
327 if (par_override
|| t
->speed_hz
|| t
->bits_per_word
) {
329 status
= omap1_spi100k_setup_transfer(spi
, t
);
332 if (!t
->speed_hz
&& !t
->bits_per_word
)
337 omap1_spi100k_force_cs(spi100k
, 1);
344 count
= omap1_spi100k_txrx_pio(spi
, t
);
345 m
->actual_length
+= count
;
347 if (count
!= t
->len
) {
354 udelay(t
->delay_usecs
);
356 /* ignore the "leave it on after last xfer" hint */
359 omap1_spi100k_force_cs(spi100k
, 0);
364 /* Restore defaults if they were overriden */
367 status
= omap1_spi100k_setup_transfer(spi
, NULL
);
371 omap1_spi100k_force_cs(spi100k
, 0);
375 spi_finalize_current_message(master
);
380 static int omap1_spi100k_unprepare_hardware(struct spi_master
*master
)
382 struct omap1_spi100k
*spi100k
= spi_master_get_devdata(master
);
384 clk_disable_unprepare(spi100k
->ick
);
385 clk_disable_unprepare(spi100k
->fck
);
390 static int omap1_spi100k_probe(struct platform_device
*pdev
)
392 struct spi_master
*master
;
393 struct omap1_spi100k
*spi100k
;
399 master
= spi_alloc_master(&pdev
->dev
, sizeof(*spi100k
));
400 if (master
== NULL
) {
401 dev_dbg(&pdev
->dev
, "master allocation failed\n");
406 master
->bus_num
= pdev
->id
;
408 master
->setup
= omap1_spi100k_setup
;
409 master
->transfer_one_message
= omap1_spi100k_transfer_one_message
;
410 master
->prepare_transfer_hardware
= omap1_spi100k_prepare_hardware
;
411 master
->unprepare_transfer_hardware
= omap1_spi100k_unprepare_hardware
;
412 master
->cleanup
= NULL
;
413 master
->num_chipselect
= 2;
414 master
->mode_bits
= MODEBITS
;
415 master
->bits_per_word_mask
= SPI_BPW_RANGE_MASK(4, 32);
416 master
->min_speed_hz
= OMAP1_SPI100K_MAX_FREQ
/(1<<16);
417 master
->max_speed_hz
= OMAP1_SPI100K_MAX_FREQ
;
419 spi100k
= spi_master_get_devdata(master
);
422 * The memory region base address is taken as the platform_data.
423 * You should allocate this with ioremap() before initializing
426 spi100k
->base
= (void __iomem
*)dev_get_platdata(&pdev
->dev
);
428 spi100k
->ick
= devm_clk_get(&pdev
->dev
, "ick");
429 if (IS_ERR(spi100k
->ick
)) {
430 dev_dbg(&pdev
->dev
, "can't get spi100k_ick\n");
431 status
= PTR_ERR(spi100k
->ick
);
435 spi100k
->fck
= devm_clk_get(&pdev
->dev
, "fck");
436 if (IS_ERR(spi100k
->fck
)) {
437 dev_dbg(&pdev
->dev
, "can't get spi100k_fck\n");
438 status
= PTR_ERR(spi100k
->fck
);
442 status
= devm_spi_register_master(&pdev
->dev
, master
);
449 spi_master_put(master
);
453 static struct platform_driver omap1_spi100k_driver
= {
455 .name
= "omap1_spi100k",
457 .probe
= omap1_spi100k_probe
,
460 module_platform_driver(omap1_spi100k_driver
);
462 MODULE_DESCRIPTION("OMAP7xx SPI 100k controller driver");
463 MODULE_AUTHOR("Fabrice Crohas <fcrohas@gmail.com>");
464 MODULE_LICENSE("GPL");