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      1 /* $NetBSD: sunxi_resets.c,v 1.2 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: sunxi_resets.c,v 1.2 2021/01/27 03:10:20 thorpej Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/bus.h>
     34 #include <sys/cpu.h>
     35 #include <sys/device.h>
     36 
     37 #include <dev/fdt/fdtvar.h>
     38 
     39 #include <dev/clk/clk_backend.h>
     40 
     41 #define	RESET_REG(index)	(((index) / 32) * 4)
     42 #define	RESET_MASK(index)	__BIT((index) % 32)
     43 
     44 static const struct device_compatible_entry compat_data[] = {
     45 	{ .compat = "allwinner,sun6i-a31-clock-reset" },
     46 	DEVICE_COMPAT_EOL
     47 };
     48 
     49 struct sunxi_resets_softc {
     50 	device_t		sc_dev;
     51 	bus_space_tag_t		sc_bst;
     52 	bus_space_handle_t	sc_bsh;
     53 };
     54 
     55 #define	RESET_READ(sc, reg)		\
     56 	bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
     57 #define	RESET_WRITE(sc, reg, val)	\
     58 	bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
     59 
     60 static void *
     61 sunxi_resets_acquire(device_t dev, const void *data, size_t len)
     62 {
     63 	if (len != 4)
     64 		return NULL;
     65 
     66 	/* Specifier is an index. Just return it. */
     67 	return (void *)(uintptr_t)be32dec(data);
     68 }
     69 
     70 static void
     71 sunxi_resets_release(device_t dev, void *priv)
     72 {
     73 }
     74 
     75 static int
     76 sunxi_resets_assert(device_t dev, void *priv)
     77 {
     78 	struct sunxi_resets_softc * const sc = device_private(dev);
     79 	const uintptr_t index = (uintptr_t)priv;
     80 
     81 	const bus_size_t reset_reg = RESET_REG(index);
     82 	const uint32_t reset_mask = RESET_MASK(index);
     83 
     84 	const uint32_t val = RESET_READ(sc, reset_reg);
     85 	RESET_WRITE(sc, reset_reg, val & ~reset_mask);
     86 
     87 	return 0;
     88 }
     89 
     90 static int
     91 sunxi_resets_deassert(device_t dev, void *priv)
     92 {
     93 	struct sunxi_resets_softc * const sc = device_private(dev);
     94 	const uintptr_t index = (uintptr_t)priv;
     95 
     96 	const bus_size_t reset_reg = RESET_REG(index);
     97 	const uint32_t reset_mask = RESET_MASK(index);
     98 
     99 	const uint32_t val = RESET_READ(sc, reset_reg);
    100 	RESET_WRITE(sc, reset_reg, val | reset_mask);
    101 
    102 	return 0;
    103 }
    104 
    105 static const struct fdtbus_reset_controller_func sunxi_fdtreset_funcs = {
    106 	.acquire = sunxi_resets_acquire,
    107 	.release = sunxi_resets_release,
    108 	.reset_assert = sunxi_resets_assert,
    109 	.reset_deassert = sunxi_resets_deassert,
    110 };
    111 
    112 static int
    113 sunxi_resets_match(device_t parent, cfdata_t cf, void *aux)
    114 {
    115 	struct fdt_attach_args * const faa = aux;
    116 
    117 	return of_compatible_match(faa->faa_phandle, compat_data);
    118 }
    119 
    120 static void
    121 sunxi_resets_attach(device_t parent, device_t self, void *aux)
    122 {
    123 	struct sunxi_resets_softc * const sc = device_private(self);
    124 	struct fdt_attach_args * const faa = aux;
    125 	const int phandle = faa->faa_phandle;
    126 	bus_addr_t addr;
    127 	bus_size_t size;
    128 
    129 	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
    130 		aprint_error(": couldn't get registers\n");
    131 		return;
    132 	}
    133 
    134 	sc->sc_dev = self;
    135 	sc->sc_bst = faa->faa_bst;
    136 	if (bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh) != 0) {
    137 		aprint_error(": couldn't map registers\n");
    138 		return;
    139 	}
    140 
    141 	aprint_naive("\n");
    142 	aprint_normal("\n");
    143 
    144 	fdtbus_register_reset_controller(sc->sc_dev, phandle,
    145 	    &sunxi_fdtreset_funcs);
    146 }
    147 
    148 CFATTACH_DECL_NEW(sunxi_resets, sizeof(struct sunxi_resets_softc),
    149     sunxi_resets_match, sunxi_resets_attach, NULL, NULL);
    150