xref: /openbmc/u-boot/board/ti/beagle/beagle.c (revision ae03661f)
1 /*
2  * (C) Copyright 2004-2011
3  * Texas Instruments, <www.ti.com>
4  *
5  * Author :
6  *	Sunil Kumar <sunilsaini05@gmail.com>
7  *	Shashi Ranjan <shashiranjanmca05@gmail.com>
8  *
9  * Derived from Beagle Board and 3430 SDP code by
10  *	Richard Woodruff <r-woodruff2@ti.com>
11  *	Syed Mohammed Khasim <khasim@ti.com>
12  *
13  *
14  * See file CREDITS for list of people who contributed to this
15  * project.
16  *
17  * This program is free software; you can redistribute it and/or
18  * modify it under the terms of the GNU General Public License as
19  * published by the Free Software Foundation; either version 2 of
20  * the License, or (at your option) any later version.
21  *
22  * This program is distributed in the hope that it will be useful,
23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
25  * GNU General Public License for more details.
26  *
27  * You should have received a copy of the GNU General Public License
28  * along with this program; if not, write to the Free Software
29  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
30  * MA 02111-1307 USA
31  */
32 #include <common.h>
33 #ifdef CONFIG_STATUS_LED
34 #include <status_led.h>
35 #endif
36 #include <twl4030.h>
37 #include <linux/mtd/nand.h>
38 #include <asm/io.h>
39 #include <asm/arch/mmc_host_def.h>
40 #include <asm/arch/mux.h>
41 #include <asm/arch/mem.h>
42 #include <asm/arch/sys_proto.h>
43 #include <asm/gpio.h>
44 #include <asm/mach-types.h>
45 #ifdef CONFIG_USB_EHCI
46 #include <usb.h>
47 #include <asm/arch/clocks.h>
48 #include <asm/arch/clocks_omap3.h>
49 #include <asm/arch/ehci_omap3.h>
50 /* from drivers/usb/host/ehci-core.h */
51 extern struct ehci_hccr *hccr;
52 extern volatile struct ehci_hcor *hcor;
53 #endif
54 #include "beagle.h"
55 #include <command.h>
56 
57 #define pr_debug(fmt, args...) debug(fmt, ##args)
58 
59 #define TWL4030_I2C_BUS			0
60 #define EXPANSION_EEPROM_I2C_BUS	1
61 #define EXPANSION_EEPROM_I2C_ADDRESS	0x50
62 
63 #define TINCANTOOLS_ZIPPY		0x01000100
64 #define TINCANTOOLS_ZIPPY2		0x02000100
65 #define TINCANTOOLS_TRAINER		0x04000100
66 #define TINCANTOOLS_SHOWDOG		0x03000100
67 #define KBADC_BEAGLEFPGA		0x01000600
68 #define LW_BEAGLETOUCH			0x01000700
69 #define BRAINMUX_LCDOG			0x01000800
70 #define BRAINMUX_LCDOGTOUCH		0x02000800
71 #define BBTOYS_WIFI			0x01000B00
72 #define BBTOYS_VGA			0x02000B00
73 #define BBTOYS_LCD			0x03000B00
74 #define BEAGLE_NO_EEPROM		0xffffffff
75 
76 DECLARE_GLOBAL_DATA_PTR;
77 
78 static struct {
79 	unsigned int device_vendor;
80 	unsigned char revision;
81 	unsigned char content;
82 	char fab_revision[8];
83 	char env_var[16];
84 	char env_setting[64];
85 } expansion_config;
86 
87 /*
88  * Routine: board_init
89  * Description: Early hardware init.
90  */
91 int board_init(void)
92 {
93 	gpmc_init(); /* in SRAM or SDRAM, finish GPMC */
94 	/* board id for Linux */
95 	gd->bd->bi_arch_number = MACH_TYPE_OMAP3_BEAGLE;
96 	/* boot param addr */
97 	gd->bd->bi_boot_params = (OMAP34XX_SDRC_CS0 + 0x100);
98 
99 #if defined(CONFIG_STATUS_LED) && defined(STATUS_LED_BOOT)
100 	status_led_set (STATUS_LED_BOOT, STATUS_LED_ON);
101 #endif
102 
103 	return 0;
104 }
105 
106 /*
107  * Routine: get_board_revision
108  * Description: Detect if we are running on a Beagle revision Ax/Bx,
109  *		C1/2/3, C4 or xM. This can be done by reading
110  *		the level of GPIO173, GPIO172 and GPIO171. This should
111  *		result in
112  *		GPIO173, GPIO172, GPIO171: 1 1 1 => Ax/Bx
113  *		GPIO173, GPIO172, GPIO171: 1 1 0 => C1/2/3
114  *		GPIO173, GPIO172, GPIO171: 1 0 1 => C4
115  *		GPIO173, GPIO172, GPIO171: 0 0 0 => xM
116  */
117 int get_board_revision(void)
118 {
119 	int revision;
120 
121 	if (!gpio_request(171, "") &&
122 	    !gpio_request(172, "") &&
123 	    !gpio_request(173, "")) {
124 
125 		gpio_direction_input(171);
126 		gpio_direction_input(172);
127 		gpio_direction_input(173);
128 
129 		revision = gpio_get_value(173) << 2 |
130 			   gpio_get_value(172) << 1 |
131 			   gpio_get_value(171);
132 	} else {
133 		printf("Error: unable to acquire board revision GPIOs\n");
134 		revision = -1;
135 	}
136 
137 	return revision;
138 }
139 
140 #ifdef CONFIG_SPL_BUILD
141 /*
142  * Routine: get_board_mem_timings
143  * Description: If we use SPL then there is no x-loader nor config header
144  * so we have to setup the DDR timings ourself on both banks.
145  */
146 void get_board_mem_timings(u32 *mcfg, u32 *ctrla, u32 *ctrlb, u32 *rfr_ctrl,
147 		u32 *mr)
148 {
149 	int pop_mfr, pop_id;
150 
151 	/*
152 	 * We need to identify what PoP memory is on the board so that
153 	 * we know what timings to use.  If we can't identify it then
154 	 * we know it's an xM.  To map the ID values please see nand_ids.c
155 	 */
156 	identify_nand_chip(&pop_mfr, &pop_id);
157 
158 	*mr = MICRON_V_MR_165;
159 	switch (get_board_revision()) {
160 	case REVISION_C4:
161 		if (pop_mfr == NAND_MFR_STMICRO && pop_id == 0xba) {
162 			/* 512MB DDR */
163 			*mcfg = NUMONYX_V_MCFG_165(512 << 20);
164 			*ctrla = NUMONYX_V_ACTIMA_165;
165 			*ctrlb = NUMONYX_V_ACTIMB_165;
166 			*rfr_ctrl = SDP_3430_SDRC_RFR_CTRL_165MHz;
167 			break;
168 		} else if (pop_mfr == NAND_MFR_MICRON && pop_id == 0xbc) {
169 			/* Beagleboard Rev C5, 256MB DDR */
170 			*mcfg = MICRON_V_MCFG_200(256 << 20);
171 			*ctrla = MICRON_V_ACTIMA_200;
172 			*ctrlb = MICRON_V_ACTIMB_200;
173 			*rfr_ctrl = SDP_3430_SDRC_RFR_CTRL_200MHz;
174 			break;
175 		}
176 	case REVISION_XM_A:
177 	case REVISION_XM_B:
178 	case REVISION_XM_C:
179 		if (pop_mfr == 0) {
180 			/* 256MB DDR */
181 			*mcfg = MICRON_V_MCFG_200(256 << 20);
182 			*ctrla = MICRON_V_ACTIMA_200;
183 			*ctrlb = MICRON_V_ACTIMB_200;
184 			*rfr_ctrl = SDP_3430_SDRC_RFR_CTRL_200MHz;
185 		} else {
186 			/* 512MB DDR */
187 			*mcfg = NUMONYX_V_MCFG_165(512 << 20);
188 			*ctrla = NUMONYX_V_ACTIMA_165;
189 			*ctrlb = NUMONYX_V_ACTIMB_165;
190 			*rfr_ctrl = SDP_3430_SDRC_RFR_CTRL_165MHz;
191 		}
192 		break;
193 	default:
194 		/* Assume 128MB and Micron/165MHz timings to be safe */
195 		*mcfg = MICRON_V_MCFG_165(128 << 20);
196 		*ctrla = MICRON_V_ACTIMA_165;
197 		*ctrlb = MICRON_V_ACTIMB_165;
198 		*rfr_ctrl = SDP_3430_SDRC_RFR_CTRL_165MHz;
199 	}
200 }
201 #endif
202 
203 /*
204  * Routine: get_expansion_id
205  * Description: This function checks for expansion board by checking I2C
206  *		bus 1 for the availability of an AT24C01B serial EEPROM.
207  *		returns the device_vendor field from the EEPROM
208  */
209 unsigned int get_expansion_id(void)
210 {
211 	i2c_set_bus_num(EXPANSION_EEPROM_I2C_BUS);
212 
213 	/* return BEAGLE_NO_EEPROM if eeprom doesn't respond */
214 	if (i2c_probe(EXPANSION_EEPROM_I2C_ADDRESS) == 1) {
215 		i2c_set_bus_num(TWL4030_I2C_BUS);
216 		return BEAGLE_NO_EEPROM;
217 	}
218 
219 	/* read configuration data */
220 	i2c_read(EXPANSION_EEPROM_I2C_ADDRESS, 0, 1, (u8 *)&expansion_config,
221 		 sizeof(expansion_config));
222 
223 	i2c_set_bus_num(TWL4030_I2C_BUS);
224 
225 	return expansion_config.device_vendor;
226 }
227 
228 /*
229  * Configure DSS to display background color on DVID
230  * Configure VENC to display color bar on S-Video
231  */
232 void beagle_display_init(void)
233 {
234 	omap3_dss_venc_config(&venc_config_std_tv, VENC_HEIGHT, VENC_WIDTH);
235 	switch (get_board_revision()) {
236 	case REVISION_AXBX:
237 	case REVISION_CX:
238 	case REVISION_C4:
239 		omap3_dss_panel_config(&dvid_cfg);
240 		break;
241 	case REVISION_XM_A:
242 	case REVISION_XM_B:
243 	case REVISION_XM_C:
244 	default:
245 		omap3_dss_panel_config(&dvid_cfg_xm);
246 		break;
247 	}
248 }
249 
250 /*
251  * Routine: misc_init_r
252  * Description: Configure board specific parts
253  */
254 int misc_init_r(void)
255 {
256 	struct gpio *gpio5_base = (struct gpio *)OMAP34XX_GPIO5_BASE;
257 	struct gpio *gpio6_base = (struct gpio *)OMAP34XX_GPIO6_BASE;
258 	struct control_prog_io *prog_io_base = (struct control_prog_io *)OMAP34XX_CTRL_BASE;
259 
260 	/* Enable i2c2 pullup resisters */
261 	writel(~(PRG_I2C2_PULLUPRESX), &prog_io_base->io1);
262 
263 	switch (get_board_revision()) {
264 	case REVISION_AXBX:
265 		printf("Beagle Rev Ax/Bx\n");
266 		setenv("beaglerev", "AxBx");
267 		break;
268 	case REVISION_CX:
269 		printf("Beagle Rev C1/C2/C3\n");
270 		setenv("beaglerev", "Cx");
271 		MUX_BEAGLE_C();
272 		break;
273 	case REVISION_C4:
274 		printf("Beagle Rev C4\n");
275 		setenv("beaglerev", "C4");
276 		MUX_BEAGLE_C();
277 		/* Set VAUX2 to 1.8V for EHCI PHY */
278 		twl4030_pmrecv_vsel_cfg(TWL4030_PM_RECEIVER_VAUX2_DEDICATED,
279 					TWL4030_PM_RECEIVER_VAUX2_VSEL_18,
280 					TWL4030_PM_RECEIVER_VAUX2_DEV_GRP,
281 					TWL4030_PM_RECEIVER_DEV_GRP_P1);
282 		break;
283 	case REVISION_XM_A:
284 		printf("Beagle xM Rev A\n");
285 		setenv("beaglerev", "xMA");
286 		MUX_BEAGLE_XM();
287 		/* Set VAUX2 to 1.8V for EHCI PHY */
288 		twl4030_pmrecv_vsel_cfg(TWL4030_PM_RECEIVER_VAUX2_DEDICATED,
289 					TWL4030_PM_RECEIVER_VAUX2_VSEL_18,
290 					TWL4030_PM_RECEIVER_VAUX2_DEV_GRP,
291 					TWL4030_PM_RECEIVER_DEV_GRP_P1);
292 		break;
293 	case REVISION_XM_B:
294 		printf("Beagle xM Rev B\n");
295 		setenv("beaglerev", "xMB");
296 		MUX_BEAGLE_XM();
297 		/* Set VAUX2 to 1.8V for EHCI PHY */
298 		twl4030_pmrecv_vsel_cfg(TWL4030_PM_RECEIVER_VAUX2_DEDICATED,
299 					TWL4030_PM_RECEIVER_VAUX2_VSEL_18,
300 					TWL4030_PM_RECEIVER_VAUX2_DEV_GRP,
301 					TWL4030_PM_RECEIVER_DEV_GRP_P1);
302 		break;
303 	case REVISION_XM_C:
304 		printf("Beagle xM Rev C\n");
305 		setenv("beaglerev", "xMC");
306 		MUX_BEAGLE_XM();
307 		/* Set VAUX2 to 1.8V for EHCI PHY */
308 		twl4030_pmrecv_vsel_cfg(TWL4030_PM_RECEIVER_VAUX2_DEDICATED,
309 					TWL4030_PM_RECEIVER_VAUX2_VSEL_18,
310 					TWL4030_PM_RECEIVER_VAUX2_DEV_GRP,
311 					TWL4030_PM_RECEIVER_DEV_GRP_P1);
312 		break;
313 	default:
314 		printf("Beagle unknown 0x%02x\n", get_board_revision());
315 		MUX_BEAGLE_XM();
316 		/* Set VAUX2 to 1.8V for EHCI PHY */
317 		twl4030_pmrecv_vsel_cfg(TWL4030_PM_RECEIVER_VAUX2_DEDICATED,
318 					TWL4030_PM_RECEIVER_VAUX2_VSEL_18,
319 					TWL4030_PM_RECEIVER_VAUX2_DEV_GRP,
320 					TWL4030_PM_RECEIVER_DEV_GRP_P1);
321 	}
322 
323 	switch (get_expansion_id()) {
324 	case TINCANTOOLS_ZIPPY:
325 		printf("Recognized Tincantools Zippy board (rev %d %s)\n",
326 			expansion_config.revision,
327 			expansion_config.fab_revision);
328 		MUX_TINCANTOOLS_ZIPPY();
329 		setenv("buddy", "zippy");
330 		break;
331 	case TINCANTOOLS_ZIPPY2:
332 		printf("Recognized Tincantools Zippy2 board (rev %d %s)\n",
333 			expansion_config.revision,
334 			expansion_config.fab_revision);
335 		MUX_TINCANTOOLS_ZIPPY();
336 		setenv("buddy", "zippy2");
337 		break;
338 	case TINCANTOOLS_TRAINER:
339 		printf("Recognized Tincantools Trainer board (rev %d %s)\n",
340 			expansion_config.revision,
341 			expansion_config.fab_revision);
342 		MUX_TINCANTOOLS_ZIPPY();
343 		MUX_TINCANTOOLS_TRAINER();
344 		setenv("buddy", "trainer");
345 		break;
346 	case TINCANTOOLS_SHOWDOG:
347 		printf("Recognized Tincantools Showdow board (rev %d %s)\n",
348 			expansion_config.revision,
349 			expansion_config.fab_revision);
350 		/* Place holder for DSS2 definition for showdog lcd */
351 		setenv("defaultdisplay", "showdoglcd");
352 		setenv("buddy", "showdog");
353 		break;
354 	case KBADC_BEAGLEFPGA:
355 		printf("Recognized KBADC Beagle FPGA board\n");
356 		MUX_KBADC_BEAGLEFPGA();
357 		setenv("buddy", "beaglefpga");
358 		break;
359 	case LW_BEAGLETOUCH:
360 		printf("Recognized Liquidware BeagleTouch board\n");
361 		setenv("buddy", "beagletouch");
362 		break;
363 	case BRAINMUX_LCDOG:
364 		printf("Recognized Brainmux LCDog board\n");
365 		setenv("buddy", "lcdog");
366 		break;
367 	case BRAINMUX_LCDOGTOUCH:
368 		printf("Recognized Brainmux LCDog Touch board\n");
369 		setenv("buddy", "lcdogtouch");
370 		break;
371 	case BBTOYS_WIFI:
372 		printf("Recognized BeagleBoardToys WiFi board\n");
373 		MUX_BBTOYS_WIFI()
374 		setenv("buddy", "bbtoys-wifi");
375 		break;;
376 	case BBTOYS_VGA:
377 		printf("Recognized BeagleBoardToys VGA board\n");
378 		break;;
379 	case BBTOYS_LCD:
380 		printf("Recognized BeagleBoardToys LCD board\n");
381 		break;;
382 	case BEAGLE_NO_EEPROM:
383 		printf("No EEPROM on expansion board\n");
384 		setenv("buddy", "none");
385 		break;
386 	default:
387 		printf("Unrecognized expansion board: %x\n",
388 			expansion_config.device_vendor);
389 		setenv("buddy", "unknown");
390 	}
391 
392 	if (expansion_config.content == 1)
393 		setenv(expansion_config.env_var, expansion_config.env_setting);
394 
395 	twl4030_power_init();
396 	switch (get_board_revision()) {
397 	case REVISION_XM_A:
398 	case REVISION_XM_B:
399 		twl4030_led_init(TWL4030_LED_LEDEN_LEDBON);
400 		break;
401 	default:
402 		twl4030_led_init(TWL4030_LED_LEDEN_LEDAON | TWL4030_LED_LEDEN_LEDBON);
403 		break;
404 	}
405 
406 	/* Set GPIO states before they are made outputs */
407 	writel(GPIO23 | GPIO10 | GPIO8 | GPIO2 | GPIO1,
408 		&gpio6_base->setdataout);
409 	writel(GPIO31 | GPIO30 | GPIO29 | GPIO28 | GPIO22 | GPIO21 |
410 		GPIO15 | GPIO14 | GPIO13 | GPIO12, &gpio5_base->setdataout);
411 
412 	/* Configure GPIOs to output */
413 	writel(~(GPIO23 | GPIO10 | GPIO8 | GPIO2 | GPIO1), &gpio6_base->oe);
414 	writel(~(GPIO31 | GPIO30 | GPIO29 | GPIO28 | GPIO22 | GPIO21 |
415 		GPIO15 | GPIO14 | GPIO13 | GPIO12), &gpio5_base->oe);
416 
417 	dieid_num_r();
418 	beagle_display_init();
419 	omap3_dss_enable();
420 
421 	return 0;
422 }
423 
424 /*
425  * Routine: set_muxconf_regs
426  * Description: Setting up the configuration Mux registers specific to the
427  *		hardware. Many pins need to be moved from protect to primary
428  *		mode.
429  */
430 void set_muxconf_regs(void)
431 {
432 	MUX_BEAGLE();
433 }
434 
435 #if defined(CONFIG_GENERIC_MMC) && !defined(CONFIG_SPL_BUILD)
436 int board_mmc_init(bd_t *bis)
437 {
438 	omap_mmc_init(0);
439 	return 0;
440 }
441 #endif
442 
443 #ifdef CONFIG_USB_EHCI
444 
445 #define GPIO_PHY_RESET 147
446 
447 /* Reset is needed otherwise the kernel-driver will throw an error. */
448 int ehci_hcd_stop(void)
449 {
450 	pr_debug("Resetting OMAP3 EHCI\n");
451 	gpio_set_value(GPIO_PHY_RESET, 0);
452 	writel(OMAP_UHH_SYSCONFIG_SOFTRESET, OMAP3_UHH_BASE + OMAP_UHH_SYSCONFIG);
453 	/* disable USB clocks */
454 	struct prcm *prcm_base = (struct prcm *)PRCM_BASE;
455 	sr32(&prcm_base->iclken_usbhost, 0, 1, 0);
456 	sr32(&prcm_base->fclken_usbhost, 0, 2, 0);
457 	sr32(&prcm_base->iclken3_core, 2, 1, 0);
458 	sr32(&prcm_base->fclken3_core, 2, 1, 0);
459 	return 0;
460 }
461 
462 /* Call usb_stop() before starting the kernel */
463 void show_boot_progress(int val)
464 {
465 	if(val == 15)
466 		usb_stop();
467 }
468 
469 /*
470  * Initialize the OMAP3 EHCI controller and PHY on the BeagleBoard.
471  * Based on "drivers/usb/host/ehci-omap.c" from Linux 2.6.37.
472  * See there for additional Copyrights.
473  */
474 int ehci_hcd_init(void)
475 {
476 	pr_debug("Initializing OMAP3 ECHI\n");
477 
478 	/* Put the PHY in RESET */
479 	gpio_request(GPIO_PHY_RESET, "");
480 	gpio_direction_output(GPIO_PHY_RESET, 0);
481 	gpio_set_value(GPIO_PHY_RESET, 0);
482 
483 	/* Hold the PHY in RESET for enough time till DIR is high */
484 	/* Refer: ISSUE1 */
485 	udelay(10);
486 
487 	struct prcm *prcm_base = (struct prcm *)PRCM_BASE;
488 	/* Enable USBHOST_L3_ICLK (USBHOST_MICLK) */
489 	sr32(&prcm_base->iclken_usbhost, 0, 1, 1);
490 	/*
491 	 * Enable USBHOST_48M_FCLK (USBHOST_FCLK1)
492 	 * and USBHOST_120M_FCLK (USBHOST_FCLK2)
493 	 */
494 	sr32(&prcm_base->fclken_usbhost, 0, 2, 3);
495 	/* Enable USBTTL_ICLK */
496 	sr32(&prcm_base->iclken3_core, 2, 1, 1);
497 	/* Enable USBTTL_FCLK */
498 	sr32(&prcm_base->fclken3_core, 2, 1, 1);
499 	pr_debug("USB clocks enabled\n");
500 
501 	/* perform TLL soft reset, and wait until reset is complete */
502 	writel(OMAP_USBTLL_SYSCONFIG_SOFTRESET,
503 		OMAP3_USBTLL_BASE + OMAP_USBTLL_SYSCONFIG);
504 	/* Wait for TLL reset to complete */
505 	while (!(readl(OMAP3_USBTLL_BASE + OMAP_USBTLL_SYSSTATUS)
506 			& OMAP_USBTLL_SYSSTATUS_RESETDONE));
507 	pr_debug("TLL reset done\n");
508 
509 	writel(OMAP_USBTLL_SYSCONFIG_ENAWAKEUP |
510 		OMAP_USBTLL_SYSCONFIG_SIDLEMODE |
511 		OMAP_USBTLL_SYSCONFIG_CACTIVITY,
512 		OMAP3_USBTLL_BASE + OMAP_USBTLL_SYSCONFIG);
513 
514 	/* Put UHH in NoIdle/NoStandby mode */
515 	writel(OMAP_UHH_SYSCONFIG_ENAWAKEUP
516 		| OMAP_UHH_SYSCONFIG_SIDLEMODE
517 		| OMAP_UHH_SYSCONFIG_CACTIVITY
518 		| OMAP_UHH_SYSCONFIG_MIDLEMODE,
519 		OMAP3_UHH_BASE + OMAP_UHH_SYSCONFIG);
520 
521 	/* setup burst configurations */
522 	writel(OMAP_UHH_HOSTCONFIG_INCR4_BURST_EN
523 		| OMAP_UHH_HOSTCONFIG_INCR8_BURST_EN
524 		| OMAP_UHH_HOSTCONFIG_INCR16_BURST_EN,
525 		OMAP3_UHH_BASE + OMAP_UHH_HOSTCONFIG);
526 
527 	/*
528 	 * Refer ISSUE1:
529 	 * Hold the PHY in RESET for enough time till
530 	 * PHY is settled and ready
531 	 */
532 	udelay(10);
533 	gpio_set_value(GPIO_PHY_RESET, 1);
534 
535 	hccr = (struct ehci_hccr *)(OMAP3_EHCI_BASE);
536 	hcor = (struct ehci_hcor *)(OMAP3_EHCI_BASE + 0x10);
537 
538 	pr_debug("OMAP3 EHCI init done\n");
539 	return 0;
540 }
541 
542 #endif /* CONFIG_USB_EHCI */
543 
544 #ifndef CONFIG_SPL_BUILD
545 /*
546  * This command returns the status of the user button on beagle xM
547  * Input - none
548  * Returns - 	1 if button is held down
549  *		0 if button is not held down
550  */
551 int do_userbutton(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
552 {
553 	int     button = 0;
554 	int	gpio;
555 
556 	/*
557 	 * pass address parameter as argv[0] (aka command name),
558 	 * and all remaining args
559 	 */
560 	switch (get_board_revision()) {
561 	case REVISION_AXBX:
562 	case REVISION_CX:
563 	case REVISION_C4:
564 		gpio = 7;
565 		break;
566 	case REVISION_XM_A:
567 	case REVISION_XM_B:
568 	case REVISION_XM_C:
569 	default:
570 		gpio = 4;
571 		break;
572 	}
573 	gpio_request(gpio, "");
574 	gpio_direction_input(gpio);
575 	printf("The user button is currently ");
576 	if (gpio_get_value(gpio))
577 	{
578 		button = 1;
579 		printf("PRESSED.\n");
580 	}
581 	else
582 	{
583 		button = 0;
584 		printf("NOT pressed.\n");
585 	}
586 
587 	return !button;
588 }
589 
590 /* -------------------------------------------------------------------- */
591 
592 U_BOOT_CMD(
593 	userbutton, CONFIG_SYS_MAXARGS, 1,	do_userbutton,
594 	"Return the status of the BeagleBoard USER button",
595 	""
596 );
597 #endif
598