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      1 /* $NetBSD: vexpress_sysreg.c,v 1.4 2021/01/27 03:10:20 thorpej Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2017 Jared McNeill <jmcneill (at) invisible.ca>
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: vexpress_sysreg.c,v 1.4 2021/01/27 03:10:20 thorpej Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/bus.h>
     34 #include <sys/device.h>
     35 #include <sys/systm.h>
     36 #include <sys/kernel.h>
     37 
     38 #include <dev/fdt/fdtvar.h>
     39 
     40 #define	SYS_CFGDATA	0x00a0
     41 #define	SYS_CFGCTRL	0x00a4
     42 #define	 SYS_CFGCTRL_START	__BIT(31)
     43 #define	 SYS_CFGCTRL_WRITE	__BIT(30)
     44 #define	 SYS_CFGCTRL_FUNCTION	__BITS(25,20)
     45 #define	  SYS_CFGCTRL_FUNCTION_SHUTDOWN	8
     46 #define	  SYS_CFGCTRL_FUNCTION_REBOOT	9
     47 #define	 SYS_CFGCTRL_SITE	__BITS(17,16)
     48 #define	  SYS_CFGCTRL_SITE_MB		0
     49 #define	SYS_CFGSTAT	0x00a8
     50 
     51 static int	vexpress_sysreg_match(device_t, cfdata_t, void *);
     52 static void	vexpress_sysreg_attach(device_t, device_t, void *);
     53 
     54 static const struct device_compatible_entry compat_data[] = {
     55 	{ .compat = "arm,vexpress-sysreg" },
     56 	DEVICE_COMPAT_EOL
     57 };
     58 
     59 struct vexpress_sysreg_softc {
     60 	device_t		sc_dev;
     61 	bus_space_tag_t		sc_bst;
     62 	bus_space_handle_t	sc_bsh;
     63 };
     64 
     65 CFATTACH_DECL_NEW(vexpress_sysreg, sizeof(struct vexpress_sysreg_softc),
     66 	vexpress_sysreg_match, vexpress_sysreg_attach, NULL, NULL);
     67 
     68 static void
     69 vexpress_sysreg_write(device_t dev, u_int func, u_int site)
     70 {
     71 	struct vexpress_sysreg_softc * const sc = device_private(dev);
     72 
     73 	const uint32_t cfgctrl = SYS_CFGCTRL_START | SYS_CFGCTRL_WRITE |
     74 	    __SHIFTIN(func, SYS_CFGCTRL_FUNCTION) |
     75 	    __SHIFTIN(site, SYS_CFGCTRL_SITE);
     76 
     77 	bus_space_write_4(sc->sc_bst, sc->sc_bsh, SYS_CFGSTAT, 0);
     78 	bus_space_write_4(sc->sc_bst, sc->sc_bsh, SYS_CFGDATA, 0);
     79 	bus_space_write_4(sc->sc_bst, sc->sc_bsh, SYS_CFGCTRL, cfgctrl);
     80 }
     81 
     82 static void
     83 vexpress_sysreg_reset(device_t dev)
     84 {
     85 	delay(1000000);
     86 	vexpress_sysreg_write(dev, SYS_CFGCTRL_FUNCTION_REBOOT, SYS_CFGCTRL_SITE_MB);
     87 }
     88 
     89 static void
     90 vexpress_sysreg_poweroff(device_t dev)
     91 {
     92 	delay(1000000);
     93 	vexpress_sysreg_write(dev, SYS_CFGCTRL_FUNCTION_SHUTDOWN, SYS_CFGCTRL_SITE_MB);
     94 }
     95 
     96 static struct fdtbus_power_controller_func vexpress_sysreg_power_funcs = {
     97 	.reset = vexpress_sysreg_reset,
     98 	.poweroff = vexpress_sysreg_poweroff,
     99 };
    100 
    101 static int
    102 vexpress_sysreg_match(device_t parent, cfdata_t cf, void *aux)
    103 {
    104 	struct fdt_attach_args * const faa = aux;
    105 
    106 	return of_compatible_match(faa->faa_phandle, compat_data);
    107 }
    108 
    109 static void
    110 vexpress_sysreg_attach(device_t parent, device_t self, void *aux)
    111 {
    112 	struct vexpress_sysreg_softc * const sc = device_private(self);
    113 	struct fdt_attach_args * const faa = aux;
    114 	const int phandle = faa->faa_phandle;
    115 	bus_addr_t addr;
    116 	bus_size_t size;
    117 
    118 	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
    119 		aprint_error(": missing 'reg' property\n");
    120 		return;
    121 	}
    122 
    123 	sc->sc_dev = self;
    124 	sc->sc_bst = faa->faa_bst;
    125 	if (bus_space_map(faa->faa_bst, addr, size, 0, &sc->sc_bsh)) {
    126 		aprint_error(": couldn't map device\n");
    127 		return;
    128 	}
    129 
    130 	aprint_naive("\n");
    131 	aprint_normal("\n");
    132 
    133 	fdtbus_register_power_controller(self, phandle,
    134 	    &vexpress_sysreg_power_funcs);
    135 }
    136