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pl061gpio_fdt.c revision 1.1.4.1
      1 /* $NetBSD: pl061gpio_fdt.c,v 1.1.4.1 2019/06/10 22:07:08 christos Exp $ */
      2 
      3 /*
      4  * Copyright (c) 2018 Jonathan A. Kollasch
      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 COPYRIGHT HOLDERS AND CONTRIBUTORS
     17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
     20  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     21  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     22  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     23  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     24  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     25  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     26  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: pl061gpio_fdt.c,v 1.1.4.1 2019/06/10 22:07:08 christos Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/bus.h>
     34 #include <sys/device.h>
     35 #include <sys/intr.h>
     36 #include <sys/systm.h>
     37 #include <sys/kernel.h>
     38 #include <sys/kmem.h>
     39 #include <sys/gpio.h>
     40 
     41 #include <dev/gpio/gpiovar.h>
     42 
     43 #include <dev/ic/pl061reg.h>
     44 #include <dev/ic/pl061var.h>
     45 
     46 #include <dev/fdt/fdtvar.h>
     47 
     48 static int	plgpio_fdt_match(device_t, cfdata_t, void *);
     49 static void	plgpio_fdt_attach(device_t, device_t, void *);
     50 
     51 static void *	plgpio_fdt_acquire(device_t, const void *,
     52 		    size_t, int);
     53 static void	plgpio_fdt_release(device_t, void *);
     54 static int	plgpio_fdt_read(device_t, void *, bool);
     55 static void	plgpio_fdt_write(device_t, void *, int, bool);
     56 
     57 struct fdtbus_gpio_controller_func plgpio_fdt_funcs = {
     58 	.acquire = plgpio_fdt_acquire,
     59 	.release = plgpio_fdt_release,
     60 	.read = plgpio_fdt_read,
     61 	.write = plgpio_fdt_write
     62 };
     63 
     64 struct plgpio_fdt_pin {
     65 	struct plgpio_softc *	pin_sc;
     66 	int			pin_no;
     67 	u_int			pin_flags;
     68 	bool			pin_actlo;
     69 };
     70 
     71 CFATTACH_DECL_NEW(plgpio_fdt, sizeof(struct plgpio_softc),
     72 	plgpio_fdt_match, plgpio_fdt_attach, NULL, NULL);
     73 
     74 static int
     75 plgpio_fdt_match(device_t parent, cfdata_t cf, void *aux)
     76 {
     77 	const char * const compatible[] = {
     78 		"arm,pl061",
     79 		NULL
     80 	};
     81 	struct fdt_attach_args * const faa = aux;
     82 
     83 	return of_match_compatible(faa->faa_phandle, compatible);
     84 }
     85 
     86 static void
     87 plgpio_fdt_attach(device_t parent, device_t self, void *aux)
     88 {
     89 	struct plgpio_softc * const sc = device_private(self);
     90 	struct fdt_attach_args * const faa = aux;
     91 	bus_addr_t addr;
     92 	bus_size_t size;
     93 	int error;
     94 
     95 	if (fdtbus_get_reg(faa->faa_phandle, 0, &addr, &size) != 0) {
     96 		aprint_error(": couldn't get registers\n");
     97 		return;
     98 	}
     99 
    100 	sc->sc_dev = self;
    101 	sc->sc_bst = faa->faa_bst;
    102 	error = bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh);
    103 	if (error) {
    104 		aprint_error(": couldn't map %#"PRIx64": %d", (uint64_t)addr, error);
    105 		return;
    106 	}
    107 
    108 	aprint_naive("\n");
    109 	aprint_normal(": GPIO\n");
    110 
    111 	plgpio_attach(sc);
    112 
    113 	fdtbus_register_gpio_controller(self, faa->faa_phandle,
    114 	    &plgpio_fdt_funcs);
    115 }
    116 
    117 static void *
    118 plgpio_fdt_acquire(device_t dev, const void *data, size_t len, int flags)
    119 {
    120 	struct plgpio_softc * const sc = device_private(dev);
    121 	struct plgpio_fdt_pin *gpin;
    122 	const u_int *gpio = data;
    123 
    124 	if (len != 12)
    125 		return NULL;
    126 
    127 	const u_int pin = be32toh(gpio[1]);
    128 	const bool actlo = be32toh(gpio[2]) & 1;
    129 
    130 	if (pin > 8)
    131 		return NULL;
    132 
    133 	const uint32_t cnf = PLGPIO_READ(sc, PL061_GPIOAFSEL_REG);
    134 	if ((cnf & __BIT(pin)) != 0)
    135 		PLGPIO_WRITE(sc, PL061_GPIOAFSEL_REG, cnf & ~__BIT(pin));
    136 
    137 	gpin = kmem_zalloc(sizeof(*gpin), KM_SLEEP);
    138 	gpin->pin_sc = sc;
    139 	gpin->pin_no = pin;
    140 	gpin->pin_flags = flags;
    141 	gpin->pin_actlo = actlo;
    142 
    143 	plgpio_pin_ctl(gpin->pin_sc, gpin->pin_no, gpin->pin_flags);
    144 
    145 	return gpin;
    146 }
    147 
    148 static void
    149 plgpio_fdt_release(device_t dev, void *priv)
    150 {
    151 	struct plgpio_fdt_pin * const gpin = priv;
    152 
    153 	plgpio_pin_ctl(gpin->pin_sc, gpin->pin_no, GPIO_PIN_INPUT);
    154 	kmem_free(gpin, sizeof(*gpin));
    155 }
    156 
    157 static int
    158 plgpio_fdt_read(device_t dev, void *priv, bool raw)
    159 {
    160 	struct plgpio_fdt_pin * const gpin = priv;
    161 	int val;
    162 
    163 	val = plgpio_pin_read(gpin->pin_sc, gpin->pin_no);
    164 
    165 	if (!raw && gpin->pin_actlo)
    166 		val = !val;
    167 
    168 	return val;
    169 }
    170 
    171 static void
    172 plgpio_fdt_write(device_t dev, void *priv, int val, bool raw)
    173 {
    174 	struct plgpio_fdt_pin * const gpin = priv;
    175 
    176 	if (!raw && gpin->pin_actlo)
    177 		val = !val;
    178 
    179 	plgpio_pin_write(gpin->pin_sc, gpin->pin_no, val);
    180 }
    181