2 * omap_uwire.c -- MicroWire interface driver for OMAP
4 * Copyright 2003 MontaVista Software Inc. <source@mvista.com>
6 * Ported to 2.6 OMAP uwire interface.
7 * Copyright (C) 2004 Texas Instruments.
9 * Generalization patches by Juha Yrjölä <juha.yrjola@nokia.com>
11 * Copyright (C) 2005 David Brownell (ported to 2.6 SPI interface)
13 * This program is free software; you can redistribute it and/or modify it
14 * under the terms of the GNU General Public License as published by the
15 * Free Software Foundation; either version 2 of the License, or (at your
16 * option) any later version.
18 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
19 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
20 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
24 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
25 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 * You should have received a copy of the GNU General Public License along
30 * with this program; if not, write to the Free Software Foundation, Inc.,
31 * 675 Mass Ave, Cambridge, MA 02139, USA.
33 #include <linux/kernel.h>
34 #include <linux/init.h>
35 #include <linux/delay.h>
36 #include <linux/platform_device.h>
37 #include <linux/interrupt.h>
38 #include <linux/err.h>
39 #include <linux/clk.h>
41 #include <linux/spi/spi.h>
42 #include <linux/spi/spi_bitbang.h>
44 #include <asm/system.h>
46 #include <asm/hardware.h>
48 #include <asm/mach-types.h>
50 #include <asm/arch/mux.h>
51 #include <asm/arch/omap730.h> /* OMAP730_IO_CONF registers */
54 /* FIXME address is now a platform device resource,
55 * and irqs should show there too...
57 #define UWIRE_BASE_PHYS 0xFFFB3000
58 #define UWIRE_BASE ((void *__iomem)IO_ADDRESS(UWIRE_BASE_PHYS))
60 /* uWire Registers: */
61 #define UWIRE_IO_SIZE 0x20
62 #define UWIRE_TDR 0x00
63 #define UWIRE_RDR 0x00
64 #define UWIRE_CSR 0x01
65 #define UWIRE_SR1 0x02
66 #define UWIRE_SR2 0x03
67 #define UWIRE_SR3 0x04
68 #define UWIRE_SR4 0x05
69 #define UWIRE_SR5 0x06
72 #define RDRB (1 << 15)
73 #define CSRB (1 << 14)
74 #define START (1 << 13)
75 #define CS_CMD (1 << 12)
78 #define UWIRE_READ_FALLING_EDGE 0x0001
79 #define UWIRE_READ_RISING_EDGE 0x0000
80 #define UWIRE_WRITE_FALLING_EDGE 0x0000
81 #define UWIRE_WRITE_RISING_EDGE 0x0002
82 #define UWIRE_CS_ACTIVE_LOW 0x0000
83 #define UWIRE_CS_ACTIVE_HIGH 0x0004
84 #define UWIRE_FREQ_DIV_2 0x0000
85 #define UWIRE_FREQ_DIV_4 0x0008
86 #define UWIRE_FREQ_DIV_8 0x0010
87 #define UWIRE_CHK_READY 0x0020
88 #define UWIRE_CLK_INVERTED 0x0040
92 struct spi_bitbang bitbang;
97 unsigned bits_per_word;
101 /* REVISIT compile time constant for idx_shift? */
102 static unsigned int uwire_idx_shift;
104 static inline void uwire_write_reg(int idx, u16 val)
106 __raw_writew(val, UWIRE_BASE + (idx << uwire_idx_shift));
109 static inline u16 uwire_read_reg(int idx)
111 return __raw_readw(UWIRE_BASE + (idx << uwire_idx_shift));
114 static inline void omap_uwire_configure_mode(u8 cs, unsigned long flags)
119 if (flags & UWIRE_CLK_INVERTED)
131 w = uwire_read_reg(reg);
132 w &= ~(0x3f << shift);
134 uwire_write_reg(reg, w);
137 static int wait_uwire_csr_flag(u16 mask, u16 val, int might_not_catch)
141 unsigned long max_jiffies = jiffies + HZ;
144 w = uwire_read_reg(UWIRE_CSR);
145 if ((w & mask) == val)
147 if (time_after(jiffies, max_jiffies)) {
148 printk(KERN_ERR "%s: timeout. reg=%#06x "
149 "mask=%#06x val=%#06x\n",
150 __FUNCTION__, w, mask, val);
154 if (might_not_catch && c > 64)
160 static void uwire_set_clk1_div(int div1_idx)
164 w = uwire_read_reg(UWIRE_SR3);
167 uwire_write_reg(UWIRE_SR3, w);
170 static void uwire_chipselect(struct spi_device *spi, int value)
172 struct uwire_state *ust = spi->controller_state;
177 BUG_ON(wait_uwire_csr_flag(CSRB, 0, 0));
179 w = uwire_read_reg(UWIRE_CSR);
180 old_cs = (w >> 10) & 0x03;
181 if (value == BITBANG_CS_INACTIVE || old_cs != spi->chip_select) {
182 /* Deselect this CS, or the previous CS */
184 uwire_write_reg(UWIRE_CSR, w);
186 /* activate specfied chipselect */
187 if (value == BITBANG_CS_ACTIVE) {
188 uwire_set_clk1_div(ust->div1_idx);
190 if (spi->mode & SPI_CPOL)
191 uwire_write_reg(UWIRE_SR4, 1);
193 uwire_write_reg(UWIRE_SR4, 0);
195 w = spi->chip_select << 10;
197 uwire_write_reg(UWIRE_CSR, w);
201 static int uwire_txrx(struct spi_device *spi, struct spi_transfer *t)
203 struct uwire_state *ust = spi->controller_state;
204 unsigned len = t->len;
205 unsigned bits = ust->bits_per_word;
210 if (!t->tx_buf && !t->rx_buf)
213 /* Microwire doesn't read and write concurrently */
214 if (t->tx_buf && t->rx_buf)
217 w = spi->chip_select << 10;
221 const u8 *buf = t->tx_buf;
223 /* NOTE: DMA could be used for TX transfers */
225 /* write one or two bytes at a time */
227 /* tx bit 15 is first sent; we byteswap multibyte words
228 * (msb-first) on the way out from memory.
239 pr_debug("%s: write-%d =%04x\n",
240 spi->dev.bus_id, bits, val);
242 if (wait_uwire_csr_flag(CSRB, 0, 0))
245 uwire_write_reg(UWIRE_TDR, val);
248 val = START | w | (bits << 5);
250 uwire_write_reg(UWIRE_CSR, val);
253 /* Wait till write actually starts.
254 * This is needed with MPU clock 60+ MHz.
255 * REVISIT: we may not have time to catch it...
257 if (wait_uwire_csr_flag(CSRB, CSRB, 1))
263 /* REVISIT: save this for later to get more i/o overlap */
264 if (wait_uwire_csr_flag(CSRB, 0, 0))
267 } else if (t->rx_buf) {
270 /* read one or two bytes at a time */
278 val = START | w | (bits << 0);
279 uwire_write_reg(UWIRE_CSR, val);
282 /* Wait till read actually starts */
283 (void) wait_uwire_csr_flag(CSRB, CSRB, 1);
285 if (wait_uwire_csr_flag(RDRB | CSRB,
289 /* rx bit 0 is last received; multibyte words will
290 * be properly byteswapped on the way to memory.
292 val = uwire_read_reg(UWIRE_RDR);
293 val &= (1 << bits) - 1;
299 pr_debug("%s: read-%d =%04x\n",
300 spi->dev.bus_id, bits, val);
310 static int uwire_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
312 struct uwire_state *ust = spi->controller_state;
313 struct uwire_spi *uwire;
323 uwire = spi_master_get_devdata(spi->master);
325 if (spi->chip_select > 3) {
326 pr_debug("%s: cs%d?\n", spi->dev.bus_id, spi->chip_select);
331 bits = spi->bits_per_word;
332 if (t != NULL && t->bits_per_word)
333 bits = t->bits_per_word;
338 pr_debug("%s: wordsize %d?\n", spi->dev.bus_id, bits);
342 ust->bits_per_word = bits;
344 /* mode 0..3, clock inverted separately;
345 * standard nCS signaling;
346 * don't treat DI=high as "not ready"
348 if (spi->mode & SPI_CS_HIGH)
349 flags |= UWIRE_CS_ACTIVE_HIGH;
351 if (spi->mode & SPI_CPOL)
352 flags |= UWIRE_CLK_INVERTED;
354 switch (spi->mode & (SPI_CPOL | SPI_CPHA)) {
357 flags |= UWIRE_WRITE_RISING_EDGE | UWIRE_READ_FALLING_EDGE;
361 flags |= UWIRE_WRITE_FALLING_EDGE | UWIRE_READ_RISING_EDGE;
365 /* assume it's already enabled */
366 rate = clk_get_rate(uwire->ck);
368 hz = spi->max_speed_hz;
369 if (t != NULL && t->speed_hz)
373 pr_debug("%s: zero speed?\n", spi->dev.bus_id);
378 /* F_INT = mpu_xor_clk / DIV1 */
379 for (div1_idx = 0; div1_idx < 4; div1_idx++) {
395 div2 = (rate / div1 + hz - 1) / hz;
400 pr_debug("%s: lowest clock %ld, need %d\n",
401 spi->dev.bus_id, rate / 10 / 8, hz);
406 /* we have to cache this and reset in uwire_chipselect as this is a
407 * global parameter and another uwire device can change it under
409 ust->div1_idx = div1_idx;
410 uwire_set_clk1_div(div1_idx);
418 flags |= UWIRE_FREQ_DIV_2;
423 flags |= UWIRE_FREQ_DIV_4;
430 flags |= UWIRE_FREQ_DIV_8;
434 omap_uwire_configure_mode(spi->chip_select, flags);
435 pr_debug("%s: uwire flags %02x, armxor %lu KHz, SCK %lu KHz\n",
437 clk_get_rate(uwire->ck) / 1000,
444 static int uwire_setup(struct spi_device *spi)
446 struct uwire_state *ust = spi->controller_state;
449 ust = kzalloc(sizeof(*ust), GFP_KERNEL);
452 spi->controller_state = ust;
455 return uwire_setup_transfer(spi, NULL);
458 static void uwire_cleanup(const struct spi_device *spi)
460 kfree(spi->controller_state);
463 static void uwire_off(struct uwire_spi *uwire)
465 uwire_write_reg(UWIRE_SR3, 0);
466 clk_disable(uwire->ck);
468 spi_master_put(uwire->bitbang.master);
471 static int uwire_probe(struct platform_device *pdev)
473 struct spi_master *master;
474 struct uwire_spi *uwire;
477 master = spi_alloc_master(&pdev->dev, sizeof *uwire);
481 uwire = spi_master_get_devdata(master);
482 dev_set_drvdata(&pdev->dev, uwire);
484 uwire->ck = clk_get(&pdev->dev, "armxor_ck");
485 if (!uwire->ck || IS_ERR(uwire->ck)) {
486 dev_dbg(&pdev->dev, "no mpu_xor_clk ?\n");
487 spi_master_put(master);
490 clk_enable(uwire->ck);
492 if (cpu_is_omap730())
497 uwire_write_reg(UWIRE_SR3, 1);
499 master->bus_num = 2; /* "official" */
500 master->num_chipselect = 4;
501 master->setup = uwire_setup;
502 master->cleanup = uwire_cleanup;
504 uwire->bitbang.master = master;
505 uwire->bitbang.chipselect = uwire_chipselect;
506 uwire->bitbang.setup_transfer = uwire_setup_transfer;
507 uwire->bitbang.txrx_bufs = uwire_txrx;
509 status = spi_bitbang_start(&uwire->bitbang);
515 static int uwire_remove(struct platform_device *pdev)
517 struct uwire_spi *uwire = dev_get_drvdata(&pdev->dev);
520 // FIXME remove all child devices, somewhere ...
522 status = spi_bitbang_stop(&uwire->bitbang);
527 static struct platform_driver uwire_driver = {
529 .name = "omap_uwire",
530 .bus = &platform_bus_type,
531 .owner = THIS_MODULE,
533 .probe = uwire_probe,
534 .remove = uwire_remove,
535 // suspend ... unuse ck
539 static int __init omap_uwire_init(void)
541 /* FIXME move these into the relevant board init code. also, include
542 * H3 support; it uses tsc2101 like H2 (on a different chipselect).
545 if (machine_is_omap_h2()) {
546 /* defaults: W21 SDO, U18 SDI, V19 SCL */
547 omap_cfg_reg(N14_1610_UWIRE_CS0);
548 omap_cfg_reg(N15_1610_UWIRE_CS1);
550 if (machine_is_omap_perseus2()) {
551 /* configure pins: MPU_UW_nSCS1, MPU_UW_SDO, MPU_UW_SCLK */
552 int val = omap_readl(OMAP730_IO_CONF_9) & ~0x00EEE000;
553 omap_writel(val | 0x00AAA000, OMAP730_IO_CONF_9);
556 return platform_driver_register(&uwire_driver);
559 static void __exit omap_uwire_exit(void)
561 platform_driver_unregister(&uwire_driver);
564 subsys_initcall(omap_uwire_init);
565 module_exit(omap_uwire_exit);
567 MODULE_LICENSE("GPL");