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      1 /* $NetBSD: apple_pmgr.c,v 1.2 2022/05/10 08:10:28 skrll Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2022 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Nick Hudson
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 __KERNEL_RCSID(0, "$NetBSD: apple_pmgr.c,v 1.2 2022/05/10 08:10:28 skrll Exp $");
     34 
     35 #include <sys/param.h>
     36 
     37 #include <sys/bus.h>
     38 #include <sys/kmem.h>
     39 #include <sys/queue.h>
     40 
     41 #include <libfdt.h>
     42 #include <dev/fdt/fdtvar.h>
     43 
     44 /*
     45  * Power manager registers
     46  */
     47 #define PMGR_PS_TARGET_MASK	__BITS(3, 0)
     48 #define PMGR_PS_ACTUAL_MASK	__BITS(7, 4)
     49 #define  PMGR_PS_ACTIVE		0xf
     50 #define  PMGR_PS_PWRGATE	0x0
     51 
     52 struct apple_pmgr_softc {
     53 	device_t sc_dev;
     54 	bus_space_tag_t sc_bst;
     55 	bus_space_handle_t sc_bsh;
     56 };
     57 
     58 #define PMGR_READ(sc, reg) \
     59 	bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
     60 #define	PMGR_WRITE(sc, reg, val) \
     61 	bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
     62 
     63 
     64 static const struct device_compatible_entry compat_data[] = {
     65 	{ .compat = "apple,pmgr" },
     66 	DEVICE_COMPAT_EOL
     67 };
     68 
     69 static void
     70 apple_pmgr_enable(device_t dev, const uint32_t *data, bool enable)
     71 {
     72 	struct apple_pmgr_softc * const sc = device_private(dev);
     73 	const uint32_t pstate = enable ? PMGR_PS_ACTIVE : PMGR_PS_PWRGATE;
     74 	const int phandle = fdtbus_get_phandle_from_native(be32dec(data));
     75 
     76 	fdtbus_powerdomain_enable(phandle);
     77 
     78 	bus_size_t off;
     79 	bus_size_t size;
     80 	if (fdtbus_get_reg(phandle, 0, &off, &size) != 0 || size != 4) {
     81 		aprint_error(": invalid 'reg' property\n");
     82 		return;
     83 	}
     84 
     85 	uint32_t val = PMGR_READ(sc, off);
     86 
     87 	val &= ~PMGR_PS_TARGET_MASK;
     88 	val |= __SHIFTIN(pstate, PMGR_PS_TARGET_MASK);
     89 	PMGR_WRITE(sc, off, val);
     90 
     91 	for (int timo = 0; timo < 100; timo++) {
     92 		val = PMGR_READ(sc, off);
     93 		if (__SHIFTOUT(val, PMGR_PS_ACTUAL_MASK) == pstate)
     94 			break;
     95 		delay(1);
     96 	}
     97 }
     98 
     99 
    100 static int
    101 apple_pmgr_match(device_t parent, cfdata_t cf, void *aux)
    102 {
    103 	struct fdt_attach_args * const faa = aux;
    104 
    105 	return of_compatible_match(faa->faa_phandle, compat_data);
    106 }
    107 
    108 
    109 static void
    110 apple_pmgr_attach(device_t parent, device_t self, void *aux)
    111 {
    112 	struct apple_pmgr_softc * const sc = device_private(self);
    113 	struct fdt_attach_args * const faa = aux;
    114 	const int phandle = faa->faa_phandle;
    115 
    116 	bus_addr_t pmgr_addr;
    117 	bus_size_t pmgr_size;
    118 
    119 	int error = fdtbus_get_reg(phandle, 0, &pmgr_addr, &pmgr_size);
    120 	if (error) {
    121 		aprint_error(": couldn't get registers\n");
    122 		return;
    123 	}
    124 
    125 	sc->sc_dev = self;
    126 	sc->sc_bst = faa->faa_bst;
    127 
    128 	error = bus_space_map(faa->faa_bst, pmgr_addr, pmgr_size, 0,
    129 	    &sc->sc_bsh);
    130 	if (error) {
    131 		aprint_error(": couldn't map registers: %d\n", error);
    132 		return;
    133 	}
    134 
    135 	aprint_naive("\n");
    136 	aprint_normal(": Apple PMGR\n");
    137 
    138 	for (int node = OF_child(phandle); node; node = OF_peer(node)) {
    139 		static const struct device_compatible_entry compat_ps[] = {
    140 			{ .compat = "apple,pmgr-pwrstate" },
    141 			DEVICE_COMPAT_EOL
    142 		};
    143 
    144 		if (!of_compatible_match(node, compat_ps))
    145 			continue;
    146 
    147 		static struct fdtbus_powerdomain_controller_func funcs = {
    148 			.pdc_enable = apple_pmgr_enable,
    149 		};
    150 
    151 		fdtbus_register_powerdomain_controller(self, node, &funcs);
    152 	}
    153 }
    154 
    155 CFATTACH_DECL_NEW(apple_pmgr, sizeof(struct apple_pmgr_softc),
    156     apple_pmgr_match, apple_pmgr_attach, NULL, NULL);
    157