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/config.h>
34 #include <linux/kernel.h>
35 #include <linux/init.h>
36 #include <linux/delay.h>
37 #include <linux/platform_device.h>
38 #include <linux/interrupt.h>
39 #include <linux/err.h>
40 #include <linux/clk.h>
42 #include <linux/spi/spi.h>
43 #include <linux/spi/spi_bitbang.h>
45 #include <asm/system.h>
47 #include <asm/hardware.h>
49 #include <asm/mach-types.h>
51 #include <asm/arch/mux.h>
52 #include <asm/arch/omap730.h> /* OMAP730_IO_CONF registers */
55 /* FIXME address is now a platform device resource,
56 * and irqs should show there too...
58 #define UWIRE_BASE_PHYS 0xFFFB3000
59 #define UWIRE_BASE ((void *__iomem)IO_ADDRESS(UWIRE_BASE_PHYS))
61 /* uWire Registers: */
62 #define UWIRE_IO_SIZE 0x20
63 #define UWIRE_TDR 0x00
64 #define UWIRE_RDR 0x00
65 #define UWIRE_CSR 0x01
66 #define UWIRE_SR1 0x02
67 #define UWIRE_SR2 0x03
68 #define UWIRE_SR3 0x04
69 #define UWIRE_SR4 0x05
70 #define UWIRE_SR5 0x06
73 #define RDRB (1 << 15)
74 #define CSRB (1 << 14)
75 #define START (1 << 13)
76 #define CS_CMD (1 << 12)
79 #define UWIRE_READ_FALLING_EDGE 0x0001
80 #define UWIRE_READ_RISING_EDGE 0x0000
81 #define UWIRE_WRITE_FALLING_EDGE 0x0000
82 #define UWIRE_WRITE_RISING_EDGE 0x0002
83 #define UWIRE_CS_ACTIVE_LOW 0x0000
84 #define UWIRE_CS_ACTIVE_HIGH 0x0004
85 #define UWIRE_FREQ_DIV_2 0x0000
86 #define UWIRE_FREQ_DIV_4 0x0008
87 #define UWIRE_FREQ_DIV_8 0x0010
88 #define UWIRE_CHK_READY 0x0020
89 #define UWIRE_CLK_INVERTED 0x0040
93 struct spi_bitbang bitbang;
98 unsigned bits_per_word;
102 /* REVISIT compile time constant for idx_shift? */
103 static unsigned int uwire_idx_shift;
105 static inline void uwire_write_reg(int idx, u16 val)
107 __raw_writew(val, UWIRE_BASE + (idx << uwire_idx_shift));
110 static inline u16 uwire_read_reg(int idx)
112 return __raw_readw(UWIRE_BASE + (idx << uwire_idx_shift));
115 static inline void omap_uwire_configure_mode(u8 cs, unsigned long flags)
120 if (flags & UWIRE_CLK_INVERTED)
132 w = uwire_read_reg(reg);
133 w &= ~(0x3f << shift);
135 uwire_write_reg(reg, w);
138 static int wait_uwire_csr_flag(u16 mask, u16 val, int might_not_catch)
142 unsigned long max_jiffies = jiffies + HZ;
145 w = uwire_read_reg(UWIRE_CSR);
146 if ((w & mask) == val)
148 if (time_after(jiffies, max_jiffies)) {
149 printk(KERN_ERR "%s: timeout. reg=%#06x "
150 "mask=%#06x val=%#06x\n",
151 __FUNCTION__, w, mask, val);
155 if (might_not_catch && c > 64)
161 static void uwire_set_clk1_div(int div1_idx)
165 w = uwire_read_reg(UWIRE_SR3);
168 uwire_write_reg(UWIRE_SR3, w);
171 static void uwire_chipselect(struct spi_device *spi, int value)
173 struct uwire_state *ust = spi->controller_state;
178 BUG_ON(wait_uwire_csr_flag(CSRB, 0, 0));
180 w = uwire_read_reg(UWIRE_CSR);
181 old_cs = (w >> 10) & 0x03;
182 if (value == BITBANG_CS_INACTIVE || old_cs != spi->chip_select) {
183 /* Deselect this CS, or the previous CS */
185 uwire_write_reg(UWIRE_CSR, w);
187 /* activate specfied chipselect */
188 if (value == BITBANG_CS_ACTIVE) {
189 uwire_set_clk1_div(ust->div1_idx);
191 if (spi->mode & SPI_CPOL)
192 uwire_write_reg(UWIRE_SR4, 1);
194 uwire_write_reg(UWIRE_SR4, 0);
196 w = spi->chip_select << 10;
198 uwire_write_reg(UWIRE_CSR, w);
202 static int uwire_txrx(struct spi_device *spi, struct spi_transfer *t)
204 struct uwire_state *ust = spi->controller_state;
205 unsigned len = t->len;
206 unsigned bits = ust->bits_per_word;
211 if (!t->tx_buf && !t->rx_buf)
214 /* Microwire doesn't read and write concurrently */
215 if (t->tx_buf && t->rx_buf)
218 w = spi->chip_select << 10;
222 const u8 *buf = t->tx_buf;
224 /* NOTE: DMA could be used for TX transfers */
226 /* write one or two bytes at a time */
228 /* tx bit 15 is first sent; we byteswap multibyte words
229 * (msb-first) on the way out from memory.
240 pr_debug("%s: write-%d =%04x\n",
241 spi->dev.bus_id, bits, val);
243 uwire_write_reg(UWIRE_TDR, val);
246 val = START | w | (bits << 5);
247 if (wait_uwire_csr_flag(CSRB, 0, 0))
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;
337 if (spi->bits_per_word > 16) {
338 pr_debug("%s: wordsize %d?\n", spi->dev.bus_id,
343 ust->bits_per_word = bits;
345 /* mode 0..3, clock inverted separately;
346 * standard nCS signaling;
347 * don't treat DI=high as "not ready"
349 if (spi->mode & SPI_CS_HIGH)
350 flags |= UWIRE_CS_ACTIVE_HIGH;
352 if (spi->mode & SPI_CPOL)
353 flags |= UWIRE_CLK_INVERTED;
355 switch (spi->mode & (SPI_CPOL | SPI_CPHA)) {
358 flags |= UWIRE_WRITE_RISING_EDGE | UWIRE_READ_FALLING_EDGE;
362 flags |= UWIRE_WRITE_FALLING_EDGE | UWIRE_READ_RISING_EDGE;
366 /* assume it's already enabled */
367 rate = clk_get_rate(uwire->ck);
369 hz = spi->max_speed_hz;
370 if (t != NULL && t->speed_hz)
374 pr_debug("%s: zero speed?\n", spi->dev.bus_id, hz);
379 /* F_INT = mpu_per_clk / DIV1 */
380 for (div1_idx = 0; div1_idx < 4; div1_idx++) {
396 div2 = (rate / div1 + hz - 1) / hz;
401 pr_debug("%s: lowest clock %ld, need %d\n",
402 spi->dev.bus_id, rate / 10 / 8, hz);
407 /* we have to cache this and reset in uwire_chipselect as this is a
408 * global parameter and another uwire device can change it under
410 ust->div1_idx = div1_idx;
411 uwire_set_clk1_div(div1_idx);
419 flags |= UWIRE_FREQ_DIV_2;
424 flags |= UWIRE_FREQ_DIV_4;
431 flags |= UWIRE_FREQ_DIV_8;
435 omap_uwire_configure_mode(spi->chip_select, flags);
436 pr_debug("%s: uwire flags %02x, armper %lu KHz, SCK %lu KHz\n",
438 clk_get_rate(uwire->ck) / 1000,
445 static int uwire_setup(struct spi_device *spi)
447 struct uwire_state *ust = spi->controller_state;
450 ust = kzalloc(sizeof(*ust), SLAB_KERNEL);
453 spi->controller_state = ust;
456 return uwire_setup_transfer(spi, NULL);
459 static void uwire_cleanup(const struct spi_device *spi)
461 kfree(spi->controller_state);
464 static void uwire_off(struct uwire_spi *uwire)
466 uwire_write_reg(UWIRE_SR3, 0);
467 clk_disable(uwire->ck);
469 spi_master_put(uwire->bitbang.master);
472 static int uwire_probe(struct platform_device *pdev)
474 struct spi_master *master;
475 struct uwire_spi *uwire;
478 master = spi_alloc_master(&pdev->dev, sizeof *uwire);
482 uwire = spi_master_get_devdata(master);
483 dev_set_drvdata(&pdev->dev, uwire);
485 uwire->ck = clk_get(&pdev->dev, "armper_ck");
486 if (!uwire->ck || IS_ERR(uwire->ck)) {
487 dev_dbg(&pdev->dev, "no mpu_per_clk ?\n");
488 spi_master_put(master);
491 clk_enable(uwire->ck);
493 if (cpu_is_omap730())
498 uwire_write_reg(UWIRE_SR3, 1);
500 master->bus_num = 2; /* "official" */
501 master->num_chipselect = 4;
502 master->setup = uwire_setup;
503 master->cleanup = uwire_cleanup;
505 uwire->bitbang.master = master;
506 uwire->bitbang.chipselect = uwire_chipselect;
507 uwire->bitbang.setup_transfer = uwire_setup_transfer;
508 uwire->bitbang.txrx_bufs = uwire_txrx;
510 status = spi_bitbang_start(&uwire->bitbang);
516 static int uwire_remove(struct platform_device *pdev)
518 struct uwire_spi *uwire = dev_get_drvdata(&pdev->dev);
521 // FIXME remove all child devices, somewhere ...
523 status = spi_bitbang_stop(&uwire->bitbang);
528 static struct platform_driver uwire_driver = {
530 .name = "omap_uwire",
531 .bus = &platform_bus_type,
532 .owner = THIS_MODULE,
534 .probe = uwire_probe,
535 .remove = uwire_remove,
536 // suspend ... unuse ck
540 static int __init omap_uwire_init(void)
542 /* FIXME move these into the relevant board init code. also, include
543 * H3 support; it uses tsc2101 like H2 (on a different chipselect).
546 if (machine_is_omap_h2()) {
547 /* defaults: W21 SDO, U18 SDI, V19 SCL */
548 omap_cfg_reg(N14_1610_UWIRE_CS0);
549 omap_cfg_reg(N15_1610_UWIRE_CS1);
551 if (machine_is_omap_perseus2()) {
552 /* configure pins: MPU_UW_nSCS1, MPU_UW_SDO, MPU_UW_SCLK */
553 int val = omap_readl(OMAP730_IO_CONF_9) & ~0x00EEE000;
554 omap_writel(val | 0x00AAA000, OMAP730_IO_CONF_9);
557 return platform_driver_register(&uwire_driver);
560 static void __exit omap_uwire_exit(void)
562 platform_driver_unregister(&uwire_driver);
565 subsys_initcall(omap_uwire_init);
566 module_exit(omap_uwire_exit);
568 MODULE_LICENSE("GPL");