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pl061gpio_fdt.c revision 1.1.2.3
      1 /* $NetBSD: pl061gpio_fdt.c,v 1.1.2.3 2018/09/06 06:55:49 pgoyette 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 1.1.2.3 2018/09/06 06:55:49 pgoyette 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 #include "gpio.h"
     43 
     44 #include <dev/ic/pl061reg.h>
     45 
     46 #include <dev/fdt/fdtvar.h>
     47 
     48 static int	pl061_gpio_match(device_t, cfdata_t, void *);
     49 static void	pl061_gpio_attach(device_t, device_t, void *);
     50 
     51 static void *	pl061_gpio_fdt_acquire(device_t, const void *,
     52 		    size_t, int);
     53 static void	pl061_gpio_fdt_release(device_t, void *);
     54 static int	pl061_gpio_fdt_read(device_t, void *, bool);
     55 static void	pl061_gpio_fdt_write(device_t, void *, int, bool);
     56 
     57 struct fdtbus_gpio_controller_func pl061_gpio_funcs = {
     58 	.acquire = pl061_gpio_fdt_acquire,
     59 	.release = pl061_gpio_fdt_release,
     60 	.read = pl061_gpio_fdt_read,
     61 	.write = pl061_gpio_fdt_write
     62 };
     63 
     64 struct pl061_gpio_softc {
     65 	device_t		sc_dev;
     66 	bus_space_tag_t		sc_bst;
     67 	bus_space_handle_t	sc_bsh;
     68 
     69 	struct gpio_chipset_tag	sc_gc;
     70 	gpio_pin_t		sc_pins[8];
     71 };
     72 
     73 struct pl061_gpio_pin {
     74 	struct pl061_gpio_softc *pin_sc;
     75 	int			pin_no;
     76 	u_int			pin_flags;
     77 	bool			pin_actlo;
     78 };
     79 
     80 static int	pl061_gpio_pin_read(void *, int);
     81 static void	pl061_gpio_pin_write(void *, int, int);
     82 static void	pl061_gpio_pin_ctl(void *, int, int);
     83 
     84 CFATTACH_DECL_NEW(pl061gpio_fdt, sizeof(struct pl061_gpio_softc),
     85 	pl061_gpio_match, pl061_gpio_attach, NULL, NULL);
     86 
     87 #define PL061_WRITE(sc, reg, val) \
     88 	bus_space_write_1((sc)->sc_bst, (sc)->sc_bsh, (reg)/4, (val))
     89 #define PL061_READ(sc, reg) \
     90 	bus_space_read_1((sc)->sc_bst, (sc)->sc_bsh, (reg)/4)
     91 
     92 static int
     93 pl061_gpio_match(device_t parent, cfdata_t cf, void *aux)
     94 {
     95 	const char * const compatible[] = {
     96 		"arm,pl061",
     97 		NULL
     98 	};
     99 	struct fdt_attach_args * const faa = aux;
    100 
    101 	return of_match_compatible(faa->faa_phandle, compatible);
    102 }
    103 
    104 static void
    105 pl061_gpio_attach(device_t parent, device_t self, void *aux)
    106 {
    107 	struct pl061_gpio_softc * const sc = device_private(self);
    108 	struct fdt_attach_args * const faa = aux;
    109 	bus_addr_t addr;
    110 	bus_size_t size;
    111 	int error;
    112 	struct gpiobus_attach_args gba;
    113 	u_int pin;
    114 
    115 
    116 	if (fdtbus_get_reg(faa->faa_phandle, 0, &addr, &size) != 0) {
    117 		aprint_error(": couldn't get registers\n");
    118 		return;
    119 	}
    120 
    121 	sc->sc_dev = self;
    122 	sc->sc_bst = faa->faa_a4x_bst;
    123 	error = bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh);
    124 	if (error) {
    125 		aprint_error(": couldn't map %#"PRIx64": %d", (uint64_t)addr, error);
    126 		return;
    127 	}
    128 
    129 	aprint_naive("\n");
    130 	aprint_normal(": GPIO\n");
    131 
    132 	sc->sc_gc.gp_cookie = sc;
    133 	sc->sc_gc.gp_pin_read = pl061_gpio_pin_read;
    134 	sc->sc_gc.gp_pin_write = pl061_gpio_pin_write;
    135 	sc->sc_gc.gp_pin_ctl = pl061_gpio_pin_ctl;
    136 
    137 	const uint32_t cnf = PL061_READ(sc, PL061_GPIOAFSEL_REG);
    138 
    139 	for (pin = 0; pin < 8; pin++) {
    140 		sc->sc_pins[pin].pin_num = pin;
    141 		/* skip pins in hardware control mode */
    142 		if ((cnf & __BIT(pin)) != 0)
    143 			continue;
    144 		sc->sc_pins[pin].pin_caps =
    145 		    GPIO_PIN_INPUT | GPIO_PIN_OUTPUT |
    146 		    GPIO_PIN_TRISTATE;
    147 		sc->sc_pins[pin].pin_state =
    148 		    pl061_gpio_pin_read(sc, pin);
    149 	}
    150 
    151 	memset(&gba, 0, sizeof(gba));
    152 	gba.gba_gc = &sc->sc_gc;
    153 	gba.gba_pins = sc->sc_pins;
    154 	gba.gba_npins = 8;
    155 
    156 #if NGPIO > 0
    157 	(void)config_found_ia(sc->sc_dev, "gpiobus", &gba,
    158 	    gpiobus_print);
    159 #endif
    160 
    161 	fdtbus_register_gpio_controller(self, faa->faa_phandle,
    162 	    &pl061_gpio_funcs);
    163 
    164 }
    165 
    166 static int
    167 pl061_gpio_pin_read(void *priv, int pin)
    168 {
    169 	struct pl061_gpio_softc * const sc = priv;
    170 
    171 	const uint32_t v = PL061_READ(sc, PL061_GPIODATA_REG(1<<pin));
    172 
    173 	return (v >> pin) & 1;
    174 }
    175 
    176 static void
    177 pl061_gpio_pin_write(void *priv, int pin, int val)
    178 {
    179 	struct pl061_gpio_softc * const sc = priv;
    180 
    181 	PL061_WRITE(sc, PL061_GPIODATA_REG(1 << pin), val << pin);
    182 }
    183 
    184 static void
    185 pl061_gpio_pin_ctl(void *priv, int pin, int flags)
    186 {
    187 	struct pl061_gpio_softc * const sc = priv;
    188 	uint32_t v;
    189 
    190 	if (flags & GPIO_PIN_INPUT) {
    191 		v = PL061_READ(sc, PL061_GPIODIR_REG);
    192 		v &= ~(1 << pin);
    193 		PL061_WRITE(sc, PL061_GPIODIR_REG, v);
    194 	} else if (flags & GPIO_PIN_OUTPUT) {
    195 		v = PL061_READ(sc, PL061_GPIODIR_REG);
    196 		v |= (1 << pin);
    197 		PL061_WRITE(sc, PL061_GPIODIR_REG, v);
    198 	}
    199 }
    200 
    201 static void *
    202 pl061_gpio_fdt_acquire(device_t dev, const void *data, size_t len, int flags)
    203 {
    204 	struct pl061_gpio_softc * const sc = device_private(dev);
    205 	struct pl061_gpio_pin *gpin;
    206 	const u_int *gpio = data;
    207 
    208 	if (len != 12)
    209 		return NULL;
    210 
    211 	const u_int pin = be32toh(gpio[1]);
    212 	const bool actlo = be32toh(gpio[2]) & 1;
    213 
    214 	if (pin > 8)
    215 		return NULL;
    216 
    217 	const uint32_t cnf = PL061_READ(sc, PL061_GPIOAFSEL_REG);
    218 	if ((cnf & __BIT(pin)) != 0)
    219 		PL061_WRITE(sc, PL061_GPIOAFSEL_REG, cnf & ~__BIT(pin));
    220 
    221 	gpin = kmem_zalloc(sizeof(*gpin), KM_SLEEP);
    222 	gpin->pin_sc = sc;
    223 	gpin->pin_no = pin;
    224 	gpin->pin_flags = flags;
    225 	gpin->pin_actlo = actlo;
    226 
    227 	pl061_gpio_pin_ctl(gpin->pin_sc, gpin->pin_no, gpin->pin_flags);
    228 
    229 	return gpin;
    230 }
    231 
    232 static void
    233 pl061_gpio_fdt_release(device_t dev, void *priv)
    234 {
    235 	struct pl061_gpio_pin * const gpin = priv;
    236 
    237 	pl061_gpio_pin_ctl(gpin->pin_sc, gpin->pin_no, GPIO_PIN_INPUT);
    238 	kmem_free(gpin, sizeof(*gpin));
    239 }
    240 
    241 static int
    242 pl061_gpio_fdt_read(device_t dev, void *priv, bool raw)
    243 {
    244 	struct pl061_gpio_pin * const gpin = priv;
    245 	int val;
    246 
    247 	val = pl061_gpio_pin_read(gpin->pin_sc, gpin->pin_no);
    248 
    249 	if (!raw && gpin->pin_actlo)
    250 		val = !val;
    251 
    252 	return val;
    253 }
    254 
    255 static void
    256 pl061_gpio_fdt_write(device_t dev, void *priv, int val, bool raw)
    257 {
    258 	struct pl061_gpio_pin * const gpin = priv;
    259 
    260 	if (!raw && gpin->pin_actlo)
    261 		val = !val;
    262 
    263 	pl061_gpio_pin_write(gpin->pin_sc, gpin->pin_no, val);
    264 }
    265