xref: /src/sys/arch/arm/vexpress/vexpress_platform.c

/* $NetBSD: vexpress_platform.c,v 1.24 2025/09/06 21:02:41 thorpej Exp $ */

/*-
 * Copyright (c) 2017 Jared McNeill <jmcneill@invisible.ca>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "opt_multiprocessor.h"
#include "opt_console.h"

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: vexpress_platform.c,v 1.24 2025/09/06 21:02:41 thorpej Exp $");

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/cpu.h>
#include <sys/device.h>
#include <sys/termios.h>

#include <dev/fdt/fdtvar.h>
#include <dev/fdt/fdt_platform.h>

#include <uvm/uvm_extern.h>

#include <machine/bootconfig.h>
#include <arm/cpufunc.h>

#include <arm/fdt/arm_fdtvar.h>

#include <arm/cortex/gtmr_var.h>

#include <arm/cortex/gic_reg.h>

#include <evbarm/dev/plcomreg.h>
#include <evbarm/fdt/machdep.h>

#include <arm/vexpress/vexpress_platform.h>

#include <libfdt.h>

#define	VEXPRESS_REF_FREQ	24000000

extern struct bus_space armv7_generic_bs_tag;
extern struct arm32_bus_dma_tag arm_generic_dma_tag;

#define	SYSREG_BASE		0x1c010000
#define	SYSREG_SIZE		0x1000

#define	SYS_FLAGS		0x0030
#define	SYS_FLAGSCLR		0x0034
#define	SYS_CFGDATA		0x00a0
#define	SYS_CFGCTRL		0x00a4
#define	 SYS_CFGCTRL_START	__BIT(31)
#define	 SYS_CFGCTRL_WRITE	__BIT(30)
#define	 SYS_CFGCTRL_DCC	__BITS(29,26)
#define	 SYS_CFGCTRL_FUNCTION	__BITS(25,20)
#define	  SYS_CFGCTRL_FUNCTION_SHUTDOWN	8
#define	  SYS_CFGCTRL_FUNCTION_REBOOT	9
#define	 SYS_CFGCTRL_SITE	__BITS(17,16)
#define	 SYS_CFGCTRL_POSITION	__BITS(15,12)
#define	 SYS_CFGCTRL_DEVICE	__BITS(11,0)
#define	SYS_CFGSTAT		0x00a8
#define	 SYS_CFGSTAT_ERROR	__BIT(1)
#define	 SYS_CFGSTAT_COMPLETE	__BIT(0)

static bus_space_tag_t sysreg_bst = &armv7_generic_bs_tag;
static bus_space_handle_t sysreg_bsh;

#define	SYSREG_WRITE(o, v)	\
	bus_space_write_4(sysreg_bst, sysreg_bsh, (o), (v))

void vexpress_platform_early_putchar(char);

void __noasan
vexpress_platform_early_putchar(char c)
{
#ifdef CONSADDR
#define CONSADDR_VA ((CONSADDR - VEXPRESS_CORE_PBASE) + VEXPRESS_CORE_VBASE)
	volatile uint32_t *uartaddr = cpu_earlydevice_va_p() ?
	    (volatile uint32_t *)CONSADDR_VA :
	    (volatile uint32_t *)CONSADDR;

	while ((le32toh(uartaddr[PL01XCOM_FR / 4]) & PL01X_FR_TXFF) != 0)
		continue;

	uartaddr[PL01XCOM_DR / 4] = htole32(c);
	dsb(sy);

	while ((le32toh(uartaddr[PL01XCOM_FR / 4]) & PL01X_FR_TXFE) == 0)
		continue;
#endif
}


static int
vexpress_a15_smp_init(void)
{
	int ret = 0;
#ifdef MULTIPROCESSOR
	bus_space_tag_t gicd_bst = &armv7_generic_bs_tag;
	bus_space_handle_t gicd_bsh;

	/* Write init vec to SYS_FLAGS register */
	SYSREG_WRITE(SYS_FLAGSCLR, 0xffffffff);
	SYSREG_WRITE(SYS_FLAGS, KERN_VTOPHYS((vaddr_t)cpu_mpstart));

	/* Map GIC distributor */
	bus_space_map(gicd_bst, VEXPRESS_GIC_PBASE + GICD_BASE,
	    0x1000, 0, &gicd_bsh);

	/* Enable GIC distributor */
	bus_space_write_4(gicd_bst, gicd_bsh,
	    GICD_CTRL, GICD_CTRL_Enable);

	/* Send sw interrupt to APs */
	const uint32_t sgir = GICD_SGIR_TargetListFilter_NotMe;
	bus_space_write_4(gicd_bst, gicd_bsh, GICD_SGIR, sgir);

	/* Bitmask of CPUs (non-BSP) to start */
	for (u_int cpuindex = 1; cpuindex < arm_cpu_max; cpuindex++) {
		u_int i;
		for (i = 0x10000000; i > 0; i--) {
			if (cpu_hatched_p(cpuindex))
				break;
		}

		if (i == 0) {
			ret++;
			aprint_error("cpu%d: WARNING: AP failed to start\n",
			    cpuindex);
		}
	}

	/* Disable GIC distributor */
	bus_space_write_4(gicd_bst, gicd_bsh, GICD_CTRL, 0);
#endif
	return ret;
}


static const struct pmap_devmap *
vexpress_platform_devmap(void)
{
	static const struct pmap_devmap devmap[] = {
		DEVMAP_ENTRY(VEXPRESS_CORE_VBASE,
			     VEXPRESS_CORE_PBASE,
			     VEXPRESS_CORE_SIZE),
		DEVMAP_ENTRY(VEXPRESS_GIC_VBASE,
			     VEXPRESS_GIC_PBASE,
			     VEXPRESS_GIC_SIZE),
		DEVMAP_ENTRY_END
	};

	return devmap;
}

static void
vexpress_platform_bootstrap(void)
{
	bus_space_map(sysreg_bst, SYSREG_BASE, SYSREG_SIZE, 0,
	    &sysreg_bsh);

#ifdef MULTIPROCESSOR
	arm_cpu_max = 1 + __SHIFTOUT(armreg_l2ctrl_read(), L2CTRL_NUMCPU);
#endif
}

static void
vexpress_platform_init_attach_args(struct fdt_attach_args *faa)
{
	faa->faa_bst = &armv7_generic_bs_tag;
	faa->faa_dmat = &arm_generic_dma_tag;
}

static void
vexpress_platform_device_register(device_t self, void *aux)
{
}

static void
vexpress_platform_reset(void)
{
	SYSREG_WRITE(SYS_CFGSTAT, 0);
	SYSREG_WRITE(SYS_CFGDATA, 0);
	SYSREG_WRITE(SYS_CFGCTRL,
	    SYS_CFGCTRL_START |
	    SYS_CFGCTRL_WRITE |
	    __SHIFTIN(SYS_CFGCTRL_FUNCTION_REBOOT,
		      SYS_CFGCTRL_FUNCTION));
}

static u_int
vexpress_platform_uart_freq(void)
{
	return VEXPRESS_REF_FREQ;
}

static const struct fdt_platform vexpress_platform = {
	.fp_devmap = vexpress_platform_devmap,
	.fp_bootstrap = vexpress_platform_bootstrap,
	.fp_mpstart = vexpress_a15_smp_init,
	.fp_init_attach_args = vexpress_platform_init_attach_args,
	.fp_device_register = vexpress_platform_device_register,
	.fp_reset = vexpress_platform_reset,
	.fp_delay = gtmr_delay,
	.fp_uart_freq = vexpress_platform_uart_freq,
};

FDT_PLATFORM(vexpress, "arm,vexpress", &vexpress_platform);