U-Boot

// SPDX-License-Identifier: GPL-2.0+
/**
 * Copyright 2010-2011 Freescale Semiconductor
 * Author: Timur Tabi <timur@freescale.com>
 *
 * This file provides support for the ngPIXIS, a board-specific FPGA used on
 * some Freescale reference boards.
 *
 * A "switch" is black rectangular block on the motherboard.  It contains
 * eight "bits".  The ngPIXIS has a set of memory-mapped registers (SWx) that
 * shadow the actual physical switches.  There is also another set of
 * registers (ENx) that tell the ngPIXIS which bits of SWx should actually be
 * used to override the values of the bits in the physical switches.
 *
 * The following macros need to be defined:
 *
 * PIXIS_BASE - The virtual address of the base of the PIXIS register map
 *
 * PIXIS_LBMAP_SWITCH - The switch number (i.e. the "x" in "SWx"). This value
 *    is used in the PIXIS_SW() macro to determine which offset in
 *    the PIXIS register map corresponds to the physical switch that controls
 *    the boot bank.
 *
 * PIXIS_LBMAP_MASK - A bit mask the defines which bits in SWx to use.
 *
 * PIXIS_LBMAP_SHIFT - The shift value that corresponds to PIXIS_LBMAP_MASK.
 *
 * PIXIS_LBMAP_ALTBANK - The value to program into SWx to tell the ngPIXIS to
 *    boot from the alternate bank.
 */

#include <command.h>
#include <asm/io.h>

#include "ngpixis.h"

static u8 __pixis_read(unsigned int reg)
{
	void *p = (void *)PIXIS_BASE;

	return in_8(p + reg);
}
u8 pixis_read(unsigned int reg) __attribute__((weak, alias("__pixis_read")));

static void __pixis_write(unsigned int reg, u8 value)
{
	void *p = (void *)PIXIS_BASE;

	out_8(p + reg, value);
}
void pixis_write(unsigned int reg, u8 value)
	__attribute__((weak, alias("__pixis_write")));

/*
 * Reset the board. This ignores the ENx registers.
 */
void __pixis_reset(void)
{
	PIXIS_WRITE(rst, 0);

	while (1);
}
void pixis_reset(void) __attribute__((weak, alias("__pixis_reset")));

/*
 * Reset the board.  Like pixis_reset(), but it honors the ENx registers.
 */
void __pixis_bank_reset(void)
{
	PIXIS_WRITE(vctl, 0);
	PIXIS_WRITE(vctl, 1);

	while (1);
}
void pixis_bank_reset(void) __attribute__((weak, alias("__pixis_bank_reset")));

/**
 * Set the boot bank to the power-on default bank
 */
void __clear_altbank(void)
{
	u8 reg;

	/* Tell the ngPIXIS to use this the bits in the physical switch for the
	 * boot bank value, instead of the SWx register.  We need to be careful
	 * only to set the bits in SWx that correspond to the boot bank.
	 */
	reg = PIXIS_READ(s[PIXIS_LBMAP_SWITCH - 1].en);
	reg &= ~PIXIS_LBMAP_MASK;
	PIXIS_WRITE(s[PIXIS_LBMAP_SWITCH - 1].en, reg);
}
void clear_altbank(void) __attribute__((weak, alias("__clear_altbank")));

/**
 * Set the boot bank to the alternate bank
 */
void __set_altbank(void)
{
	u8 reg;

	/* Program the alternate bank number into the SWx register.
	 */
	reg = PIXIS_READ(s[PIXIS_LBMAP_SWITCH - 1].sw);
	reg = (reg & ~PIXIS_LBMAP_MASK) | PIXIS_LBMAP_ALTBANK;
	PIXIS_WRITE(s[PIXIS_LBMAP_SWITCH - 1].sw, reg);

	/* Tell the ngPIXIS to use this the bits in the SWx register for the
	 * boot bank value, instead of the physical switch.  We need to be
	 * careful only to set the bits in SWx that correspond to the boot bank.
	 */
	reg = PIXIS_READ(s[PIXIS_LBMAP_SWITCH - 1].en);
	reg |= PIXIS_LBMAP_MASK;
	PIXIS_WRITE(s[PIXIS_LBMAP_SWITCH - 1].en, reg);
}
void set_altbank(void) __attribute__((weak, alias("__set_altbank")));

#ifdef DEBUG
static void pixis_dump_regs(void)
{
	unsigned int i;

	printf("id=%02x\n", PIXIS_READ(id));
	printf("arch=%02x\n", PIXIS_READ(arch));
	printf("scver=%02x\n", PIXIS_READ(scver));
	printf("csr=%02x\n", PIXIS_READ(csr));
	printf("rst=%02x\n", PIXIS_READ(rst));
	printf("aux=%02x\n", PIXIS_READ(aux));
	printf("spd=%02x\n", PIXIS_READ(spd));
	printf("brdcfg0=%02x\n", PIXIS_READ(brdcfg0));
	printf("brdcfg1=%02x\n", PIXIS_READ(brdcfg1));
	printf("addr=%02x\n", PIXIS_READ(addr));
	printf("data=%02x\n", PIXIS_READ(data));
	printf("led=%02x\n", PIXIS_READ(led));
	printf("vctl=%02x\n", PIXIS_READ(vctl));
	printf("vstat=%02x\n", PIXIS_READ(vstat));
	printf("vcfgen0=%02x\n", PIXIS_READ(vcfgen0));
	printf("ocmcsr=%02x\n", PIXIS_READ(ocmcsr));
	printf("ocmmsg=%02x\n", PIXIS_READ(ocmmsg));
	printf("gmdbg=%02x\n", PIXIS_READ(gmdbg));
	printf("sclk=%02x%02x%02x\n",
	       PIXIS_READ(sclk[0]), PIXIS_READ(sclk[1]), PIXIS_READ(sclk[2]));
	printf("dclk=%02x%02x%02x\n",
	       PIXIS_READ(dclk[0]), PIXIS_READ(dclk[1]), PIXIS_READ(dclk[2]));
	printf("watch=%02x\n", PIXIS_READ(watch));

	for (i = 0; i < 8; i++) {
		printf("SW%u=%02x/%02x ", i + 1,
			PIXIS_READ(s[i].sw), PIXIS_READ(s[i].en));
	}
	putc('\n');
}
#endif

void pixis_sysclk_set(unsigned long sysclk)
{
	unsigned long freq_word;
	u8 sclk0, sclk1, sclk2;

	freq_word = ics307_sysclk_calculator(sysclk);
	sclk2 = freq_word & 0xff;
	sclk1 = (freq_word >> 8) & 0xff;
	sclk0 = (freq_word >> 16) & 0xff;

	/* set SYSCLK enable bit */
	PIXIS_WRITE(vcfgen0, 0x01);

	/* SYSCLK to required frequency */
	PIXIS_WRITE(sclk[0], sclk0);
	PIXIS_WRITE(sclk[1], sclk1);
	PIXIS_WRITE(sclk[2], sclk2);
}

int pixis_reset_cmd(struct cmd_tbl *cmdtp, int flag, int argc,
		    char *const argv[])
{
	unsigned int i;
	unsigned long sysclk;
	char *p_altbank = NULL;
#ifdef DEBUG
	char *p_dump = NULL;
#endif
	char *unknown_param = NULL;

	/* No args is a simple reset request.
	 */
	if (argc <= 1)
		pixis_reset();

	for (i = 1; i < argc; i++) {
		if (strcmp(argv[i], "altbank") == 0) {
			p_altbank = argv[i];
			continue;
		}

#ifdef DEBUG
		if (strcmp(argv[i], "dump") == 0) {
			p_dump = argv[i];
			continue;
		}
#endif
		if (strcmp(argv[i], "sysclk") == 0) {
			sysclk = simple_strtoul(argv[i + 1], NULL, 0);
			i += 1;
			pixis_sysclk_set(sysclk);
			continue;
		}

		unknown_param = argv[i];
	}

	if (unknown_param) {
		printf("Invalid option: %s\n", unknown_param);
		return 1;
	}

#ifdef DEBUG
	if (p_dump) {
		pixis_dump_regs();

		/* 'dump' ignores other commands */
		return 0;
	}
#endif

	if (p_altbank)
		set_altbank();
	else
		clear_altbank();

	pixis_bank_reset();

	/* Shouldn't be reached. */
	return 0;
}

U_BOOT_LONGHELP(pixis,
	"- hard reset to default bank\n"
	"pixis_reset altbank - reset to alternate bank\n"
#ifdef DEBUG
	"pixis_reset dump - display the PIXIS registers\n"
#endif
	"pixis_reset sysclk <SYSCLK_freq> - reset with SYSCLK frequency(KHz)\n");

U_BOOT_CMD(
	pixis_reset, CONFIG_SYS_MAXARGS, 1, pixis_reset_cmd,
	"Reset the board using the FPGA sequencer", pixis_help_text
	);