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vexpress_sysreg.c revision 1.2 
      1 /* $NetBSD: vexpress_sysreg.c,v 1.2 2017/06/02 21:26:20 jmcneill 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 1.2 2017/06/02 21:26:20 jmcneill 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 char * const compatible[] = { "arm,vexpress-sysreg", NULL };
     55 
     56 struct vexpress_sysreg_softc {
     57 	device_t		sc_dev;
     58 	bus_space_tag_t		sc_bst;
     59 	bus_space_handle_t	sc_bsh;
     60 };
     61 
     62 CFATTACH_DECL_NEW(vexpress_sysreg, sizeof(struct vexpress_sysreg_softc),
     63 	vexpress_sysreg_match, vexpress_sysreg_attach, NULL, NULL);
     64 
     65 static void
     66 vexpress_sysreg_write(device_t dev, u_int func, u_int site)
     67 {
     68 	struct vexpress_sysreg_softc * const sc = device_private(dev);
     69 
     70 	const uint32_t cfgctrl = SYS_CFGCTRL_START | SYS_CFGCTRL_WRITE |
     71 	    __SHIFTIN(func, SYS_CFGCTRL_FUNCTION) |
     72 	    __SHIFTIN(site, SYS_CFGCTRL_SITE);
     73 
     74 	bus_space_write_4(sc->sc_bst, sc->sc_bsh, SYS_CFGSTAT, 0);
     75 	bus_space_write_4(sc->sc_bst, sc->sc_bsh, SYS_CFGDATA, 0);
     76 	bus_space_write_4(sc->sc_bst, sc->sc_bsh, SYS_CFGCTRL, cfgctrl);
     77 }
     78 
     79 static void
     80 vexpress_sysreg_reset(device_t dev)
     81 {
     82 	delay(1000000);
     83 	vexpress_sysreg_write(dev, SYS_CFGCTRL_FUNCTION_REBOOT, SYS_CFGCTRL_SITE_MB);
     84 }
     85 
     86 static void
     87 vexpress_sysreg_poweroff(device_t dev)
     88 {
     89 	delay(1000000);
     90 	vexpress_sysreg_write(dev, SYS_CFGCTRL_FUNCTION_SHUTDOWN, SYS_CFGCTRL_SITE_MB);
     91 }
     92 
     93 static struct fdtbus_power_controller_func vexpress_sysreg_power_funcs = {
     94 	.reset = vexpress_sysreg_reset,
     95 	.poweroff = vexpress_sysreg_poweroff,
     96 };
     97 
     98 static int
     99 vexpress_sysreg_match(device_t parent, cfdata_t cf, void *aux)
    100 {
    101 	struct fdt_attach_args * const faa = aux;
    102 
    103 	return of_compatible(faa->faa_phandle, compatible) >= 0;
    104 }
    105 
    106 static void
    107 vexpress_sysreg_attach(device_t parent, device_t self, void *aux)
    108 {
    109 	struct vexpress_sysreg_softc * const sc = device_private(self);
    110 	struct fdt_attach_args * const faa = aux;
    111 	const int phandle = faa->faa_phandle;
    112 	bus_addr_t addr;
    113 	bus_size_t size;
    114 
    115 	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
    116 		aprint_error(": missing 'reg' property\n");
    117 		return;
    118 	}
    119 
    120 	sc->sc_dev = self;
    121 	sc->sc_bst = faa->faa_bst;
    122 	if (bus_space_map(faa->faa_bst, addr, size, 0, &sc->sc_bsh)) {
    123 		aprint_error(": couldn't map device\n");
    124 		return;
    125 	}
    126 
    127 	aprint_naive("\n");
    128 	aprint_normal("\n");
    129 
    130 	fdtbus_register_power_controller(self, phandle,
    131 	    &vexpress_sysreg_power_funcs);
    132 }
    133