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 0x0000
80 #define UWIRE_READ_RISING_EDGE 0x0001
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;
97 /* REVISIT compile time constant for idx_shift? */
98 static unsigned int uwire_idx_shift;
100 static inline void uwire_write_reg(int idx, u16 val)
102 __raw_writew(val, UWIRE_BASE + (idx << uwire_idx_shift));
105 static inline u16 uwire_read_reg(int idx)
107 return __raw_readw(UWIRE_BASE + (idx << uwire_idx_shift));
110 static inline void omap_uwire_configure_mode(u8 cs, unsigned long flags)
115 if (flags & UWIRE_CLK_INVERTED)
127 w = uwire_read_reg(reg);
128 w &= ~(0x3f << shift);
130 uwire_write_reg(reg, w);
133 static int wait_uwire_csr_flag(u16 mask, u16 val, int might_not_catch)
137 unsigned long max_jiffies = jiffies + HZ;
140 w = uwire_read_reg(UWIRE_CSR);
141 if ((w & mask) == val)
143 if (time_after(jiffies, max_jiffies)) {
144 printk(KERN_ERR "%s: timeout. reg=%#06x "
145 "mask=%#06x val=%#06x\n",
146 __FUNCTION__, w, mask, val);
150 if (might_not_catch && c > 64)
156 static void uwire_chipselect(struct spi_device *spi, int value)
160 BUG_ON(wait_uwire_csr_flag(CSRB, 0, 0));
162 /* activate/deactivate specfied chipselect */
163 if (value == BITBANG_CS_ACTIVE) {
165 if (spi->mode & SPI_CPOL)
166 uwire_write_reg(UWIRE_SR4, 1);
168 uwire_write_reg(UWIRE_SR4, 0);
170 w = spi->chip_select << 10;
174 uwire_write_reg(UWIRE_CSR, w);
177 static int uwire_txrx(struct spi_device *spi, struct spi_transfer *t)
179 unsigned len = t->len;
180 unsigned bits = spi->bits_per_word;
185 if (!t->tx_buf && !t->rx_buf)
188 /* Microwire doesn't read and write concurrently */
189 if (t->tx_buf && t->rx_buf)
192 w = spi->chip_select << 10;
196 const u8 *buf = t->tx_buf;
198 /* NOTE: DMA could be used for TX transfers */
200 /* write one or two bytes at a time */
202 /* tx is msb-aligned */
204 if (len > 1 && (!bits || bits > 8)) {
210 if (!bits || bits > 8)
217 pr_debug("%s: write-%d =%04x\n",
218 spi->dev.bus_id, bits, val);
220 uwire_write_reg(UWIRE_TDR, val);
223 val = START | w | (bits << 5);
224 if (wait_uwire_csr_flag(CSRB, 0, 0))
227 uwire_write_reg(UWIRE_CSR, val);
230 /* Wait till write actually starts.
231 * This is needed with MPU clock 60+ MHz.
232 * REVISIT: we may not have time to catch it...
234 if (wait_uwire_csr_flag(CSRB, CSRB, 1))
240 /* REVISIT: save this for later to get more i/o overlap */
241 if (wait_uwire_csr_flag(CSRB, 0, 0))
244 } else if (t->rx_buf) {
247 /* read one or two bytes at a time */
249 if (len > 1 && (!bits || bits > 8)) {
254 if (!bits || bits > 8)
260 val = START | w | (bits << 0);
261 uwire_write_reg(UWIRE_CSR, val);
264 /* Wait till read actually starts */
265 (void) wait_uwire_csr_flag(CSRB, CSRB, 1);
267 if (wait_uwire_csr_flag(RDRB | CSRB,
271 /* rx is lsb-aligned */
272 val = uwire_read_reg(UWIRE_RDR);
273 val &= (1 << bits) - 1;
279 pr_debug("%s: read-%d =%04x\n",
280 spi->dev.bus_id, bits, val);
290 static int uwire_setup(struct spi_device *spi)
292 struct uwire_spi *uwire;
298 uwire = spi_master_get_devdata(spi->master);
300 if (spi->chip_select > 3) {
301 pr_debug("%s: cs%d?\n", spi->dev.bus_id, spi->chip_select);
306 if (spi->bits_per_word > 16) {
307 pr_debug("%s: wordsize %d?\n", spi->dev.bus_id,
313 /* mode 0..3, clock inverted separately;
314 * standard nCS signaling;
315 * don't treat DI=high as "not ready"
317 if (spi->mode & SPI_CS_HIGH)
318 flags |= UWIRE_CS_ACTIVE_HIGH;
320 if (spi->mode & SPI_CPOL)
321 flags |= UWIRE_CLK_INVERTED;
323 switch (spi->mode & (SPI_CPOL | SPI_CPHA)) {
326 flags |= UWIRE_WRITE_FALLING_EDGE | UWIRE_READ_FALLING_EDGE;
330 flags |= UWIRE_WRITE_FALLING_EDGE | UWIRE_READ_RISING_EDGE;
334 /* assume it's already enabled */
335 rate = clk_get_rate(uwire->ck);
337 /* F_INT = mpu_per_clk / DIV1 */
338 div1 = (uwire_read_reg(UWIRE_SR3) >> 1) & 0x3;
340 case 0: rate /= 2; break;
341 case 1: rate /= 4; break;
342 case 2: rate /= 7; break;
343 case 3: rate /= 10; break;
346 /* SCLK = F_INT / DIV2 */
348 if (rate <= spi->max_speed_hz)
349 flags |= UWIRE_FREQ_DIV_2;
352 if (rate <= spi->max_speed_hz)
353 flags |= UWIRE_FREQ_DIV_4;
356 if (rate <= spi->max_speed_hz)
357 flags |= UWIRE_FREQ_DIV_8;
359 /* REVISIT: we could change DIV2 */
360 pr_debug("%s: lowest clock %ld, need %d, "
362 spi->dev.bus_id, rate,
363 spi->max_speed_hz, div1);
369 omap_uwire_configure_mode(spi->chip_select, flags);
370 pr_debug("%s: uwire flags %02x, armper %lu KHz, SCK %lu KHz\n",
372 clk_get_rate(uwire->ck) / 1000,
379 static void uwire_off(struct uwire_spi *uwire)
381 uwire_write_reg(UWIRE_SR3, 0);
382 clk_disable(uwire->ck);
384 spi_master_put(uwire->bitbang.master);
387 static int uwire_probe(struct platform_device *pdev)
389 struct spi_master *master;
390 struct uwire_spi *uwire;
393 master = spi_alloc_master(&pdev->dev, sizeof *uwire);
397 uwire = spi_master_get_devdata(master);
398 dev_set_drvdata(&pdev->dev, uwire);
400 uwire->ck = clk_get(&pdev->dev, "armper_ck");
401 if (!uwire->ck || IS_ERR(uwire->ck)) {
402 dev_dbg(&pdev->dev, "no mpu_per_clk ?\n");
403 spi_master_put(master);
406 clk_enable(uwire->ck);
408 if (cpu_is_omap730())
413 uwire_write_reg(UWIRE_SR3, 1);
415 master->bus_num = 2; /* "official" */
416 master->num_chipselect = 4;
417 master->setup = uwire_setup;
419 uwire->bitbang.master = master;
420 uwire->bitbang.chipselect = uwire_chipselect;
421 uwire->bitbang.txrx_bufs = uwire_txrx;
423 status = spi_bitbang_start(&uwire->bitbang);
429 static int uwire_remove(struct platform_device *pdev)
431 struct uwire_spi *uwire = dev_get_drvdata(&pdev->dev);
434 // FIXME remove all child devices, somewhere ...
436 status = spi_bitbang_stop(&uwire->bitbang);
441 static struct platform_driver uwire_driver = {
443 .name = "omap_uwire",
444 .bus = &platform_bus_type,
445 .owner = THIS_MODULE,
447 .probe = uwire_probe,
448 .remove = uwire_remove,
449 // suspend ... unuse ck
453 static int __init omap_uwire_init(void)
455 /* FIXME move these into the relevant board init code. also, include
456 * H3 support; it uses tsc2101 like H2 (on a different chipselect).
459 if (machine_is_omap_h2()) {
460 /* defaults: W21 SDO, U18 SDI, V19 SCL */
461 omap_cfg_reg(N14_1610_UWIRE_CS0);
462 omap_cfg_reg(N15_1610_UWIRE_CS1);
464 if (machine_is_omap_perseus2()) {
465 /* configure pins: MPU_UW_nSCS1, MPU_UW_SDO, MPU_UW_SCLK */
466 int val = omap_readl(OMAP730_IO_CONF_9) & ~0x00EEE000;
467 omap_writel(val | 0x00AAA000, OMAP730_IO_CONF_9);
470 return platform_driver_register(&uwire_driver);
473 static void __exit omap_uwire_exit(void)
475 platform_driver_unregister(&uwire_driver);
478 subsys_initcall(omap_uwire_init);
479 module_exit(omap_uwire_exit);
481 MODULE_LICENSE("GPL");