bcm2835_gpio.c revision 1.2.8.2
1 1.2.8.2 tls /* $NetBSD: bcm2835_gpio.c,v 1.2.8.2 2014/08/20 00:02:45 tls Exp $ */ 2 1.2.8.2 tls 3 1.2.8.2 tls /*- 4 1.2.8.2 tls * Copyright (c) 2014 The NetBSD Foundation, Inc. 5 1.2.8.2 tls * All rights reserved. 6 1.2.8.2 tls * 7 1.2.8.2 tls * This code is derived from software contributed to The NetBSD Foundation 8 1.2.8.2 tls * by Frank Kardel. 9 1.2.8.2 tls * 10 1.2.8.2 tls * Redistribution and use in source and binary forms, with or without 11 1.2.8.2 tls * modification, are permitted provided that the following conditions 12 1.2.8.2 tls * are met: 13 1.2.8.2 tls * 1. Redistributions of source code must retain the above copyright 14 1.2.8.2 tls * notice, this list of conditions and the following disclaimer. 15 1.2.8.2 tls * 2. Redistributions in binary form must reproduce the above copyright 16 1.2.8.2 tls * notice, this list of conditions and the following disclaimer in the 17 1.2.8.2 tls * documentation and/or other materials provided with the distribution. 18 1.2.8.2 tls * 19 1.2.8.2 tls * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 1.2.8.2 tls * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 1.2.8.2 tls * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 1.2.8.2 tls * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 23 1.2.8.2 tls * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 24 1.2.8.2 tls * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 25 1.2.8.2 tls * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 26 1.2.8.2 tls * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 27 1.2.8.2 tls * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 28 1.2.8.2 tls * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 29 1.2.8.2 tls * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 1.2.8.2 tls */ 31 1.2.8.2 tls 32 1.2.8.2 tls #include <sys/cdefs.h> 33 1.2.8.2 tls __KERNEL_RCSID(0, "$NetBSD: bcm2835_gpio.c,v 1.2.8.2 2014/08/20 00:02:45 tls Exp $"); 34 1.2.8.2 tls 35 1.2.8.2 tls /* 36 1.2.8.2 tls * Driver for BCM2835 GPIO 37 1.2.8.2 tls * 38 1.2.8.2 tls * see: http://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripherals.pdf 39 1.2.8.2 tls */ 40 1.2.8.2 tls 41 1.2.8.2 tls #include "gpio.h" 42 1.2.8.2 tls 43 1.2.8.2 tls #include <sys/param.h> 44 1.2.8.2 tls #include <sys/device.h> 45 1.2.8.2 tls #include <sys/systm.h> 46 1.2.8.2 tls #include <sys/mutex.h> 47 1.2.8.2 tls #include <sys/bus.h> 48 1.2.8.2 tls #include <sys/intr.h> 49 1.2.8.2 tls #include <sys/kernel.h> 50 1.2.8.2 tls #include <sys/gpio.h> 51 1.2.8.2 tls #include <dev/gpio/gpiovar.h> 52 1.2.8.2 tls 53 1.2.8.2 tls #include <sys/bitops.h> 54 1.2.8.2 tls 55 1.2.8.2 tls #include <arm/broadcom/bcm_amba.h> 56 1.2.8.2 tls #include <arm/broadcom/bcm2835reg.h> 57 1.2.8.2 tls #include <arm/broadcom/bcm2835_gpioreg.h> 58 1.2.8.2 tls #include <arm/broadcom/bcm2835_gpio_subr.h> 59 1.2.8.2 tls 60 1.2.8.2 tls /* #define BCM2835_GPIO_DEBUG */ 61 1.2.8.2 tls #ifdef BCM2835_GPIO_DEBUG 62 1.2.8.2 tls int bcm2835gpiodebug = 3; 63 1.2.8.2 tls #define DPRINTF(l, x) do { if (l <= bcm2835gpiodebug) { printf x; } } while (0) 64 1.2.8.2 tls #else 65 1.2.8.2 tls #define DPRINTF(l, x) 66 1.2.8.2 tls #endif 67 1.2.8.2 tls 68 1.2.8.2 tls struct bcmgpio_softc { 69 1.2.8.2 tls device_t sc_dev; 70 1.2.8.2 tls bus_space_tag_t sc_iot; 71 1.2.8.2 tls bus_space_handle_t sc_ioh; 72 1.2.8.2 tls struct gpio_chipset_tag sc_gpio_gc; 73 1.2.8.2 tls gpio_pin_t sc_gpio_pins[32]; 74 1.2.8.2 tls }; 75 1.2.8.2 tls 76 1.2.8.2 tls static int bcmgpio_match(device_t, cfdata_t, void *); 77 1.2.8.2 tls static void bcmgpio_attach(device_t, device_t, void *); 78 1.2.8.2 tls 79 1.2.8.2 tls #if NGPIO > 0 80 1.2.8.2 tls static int bcm2835gpio_gpio_pin_read(void *, int); 81 1.2.8.2 tls static void bcm2835gpio_gpio_pin_write(void *, int, int); 82 1.2.8.2 tls static void bcm2835gpio_gpio_pin_ctl(void *, int, int); 83 1.2.8.2 tls #endif 84 1.2.8.2 tls 85 1.2.8.2 tls CFATTACH_DECL_NEW(bcmgpio, sizeof(struct bcmgpio_softc), 86 1.2.8.2 tls bcmgpio_match, bcmgpio_attach, NULL, NULL); 87 1.2.8.2 tls 88 1.2.8.2 tls static int 89 1.2.8.2 tls bcmgpio_match(device_t parent, cfdata_t cf, void *aux) 90 1.2.8.2 tls { 91 1.2.8.2 tls struct amba_attach_args * const aaa = aux; 92 1.2.8.2 tls 93 1.2.8.2 tls if (strcmp(aaa->aaa_name, "bcmgpio") != 0) 94 1.2.8.2 tls return 0; 95 1.2.8.2 tls 96 1.2.8.2 tls return 1; 97 1.2.8.2 tls } 98 1.2.8.2 tls 99 1.2.8.2 tls static void 100 1.2.8.2 tls bcmgpio_attach(device_t parent, device_t self, void *aux) 101 1.2.8.2 tls { 102 1.2.8.2 tls struct bcmgpio_softc * const sc = device_private(self); 103 1.2.8.2 tls #if NGPIO > 0 104 1.2.8.2 tls int pin, minpin, maxpin; 105 1.2.8.2 tls u_int func; 106 1.2.8.2 tls struct gpiobus_attach_args gba; 107 1.2.8.2 tls #endif 108 1.2.8.2 tls 109 1.2.8.2 tls sc->sc_dev = self; 110 1.2.8.2 tls 111 1.2.8.2 tls #if NGPIO > 0 112 1.2.8.2 tls if (device_unit(sc->sc_dev) > 1) { 113 1.2.8.2 tls aprint_naive(" NO GPIO\n"); 114 1.2.8.2 tls aprint_normal(": NO GPIO\n"); 115 1.2.8.2 tls return; 116 1.2.8.2 tls } else if (device_unit(sc->sc_dev) == 1) { 117 1.2.8.2 tls maxpin = 53; 118 1.2.8.2 tls minpin = 32; 119 1.2.8.2 tls } else { 120 1.2.8.2 tls maxpin = 31; 121 1.2.8.2 tls minpin = 0; 122 1.2.8.2 tls } 123 1.2.8.2 tls 124 1.2.8.2 tls aprint_naive("\n"); 125 1.2.8.2 tls aprint_normal(": GPIO [%d...%d]\n", minpin, maxpin); 126 1.2.8.2 tls 127 1.2.8.2 tls /* already mapped - nothing to gain from struct amba_attach_args */ 128 1.2.8.2 tls sc->sc_iot = &bcm2835_bs_tag; 129 1.2.8.2 tls sc->sc_ioh = BCM2835_IOPHYSTOVIRT(BCM2835_GPIO_BASE); 130 1.2.8.2 tls 131 1.2.8.2 tls for (pin = minpin; pin <= maxpin; pin++) { 132 1.2.8.2 tls int epin = pin - minpin; 133 1.2.8.2 tls 134 1.2.8.2 tls sc->sc_gpio_pins[epin].pin_num = epin; 135 1.2.8.2 tls /* 136 1.2.8.2 tls * find out pins still available for GPIO 137 1.2.8.2 tls */ 138 1.2.8.2 tls func = bcm2835gpio_function_read(pin); 139 1.2.8.2 tls 140 1.2.8.2 tls if (func == BCM2835_GPIO_IN || 141 1.2.8.2 tls func == BCM2835_GPIO_OUT) { 142 1.2.8.2 tls sc->sc_gpio_pins[epin].pin_caps = GPIO_PIN_INPUT | 143 1.2.8.2 tls GPIO_PIN_OUTPUT | 144 1.2.8.2 tls GPIO_PIN_PUSHPULL | GPIO_PIN_TRISTATE | 145 1.2.8.2 tls GPIO_PIN_PULLUP | GPIO_PIN_PULLDOWN; 146 1.2.8.2 tls /* read initial state */ 147 1.2.8.2 tls sc->sc_gpio_pins[epin].pin_state = 148 1.2.8.2 tls bcm2835gpio_gpio_pin_read(sc, epin); 149 1.2.8.2 tls DPRINTF(1, ("%s: attach pin %d\n", device_xname(sc->sc_dev), pin)); 150 1.2.8.2 tls } else { 151 1.2.8.2 tls sc->sc_gpio_pins[epin].pin_caps = 0; 152 1.2.8.2 tls sc->sc_gpio_pins[epin].pin_state = 0; 153 1.2.8.2 tls DPRINTF(1, ("%s: skip pin %d - func = 0x%x\n", device_xname(sc->sc_dev), pin, func)); 154 1.2.8.2 tls } 155 1.2.8.2 tls } 156 1.2.8.2 tls 157 1.2.8.2 tls /* create controller tag */ 158 1.2.8.2 tls sc->sc_gpio_gc.gp_cookie = sc; 159 1.2.8.2 tls sc->sc_gpio_gc.gp_pin_read = bcm2835gpio_gpio_pin_read; 160 1.2.8.2 tls sc->sc_gpio_gc.gp_pin_write = bcm2835gpio_gpio_pin_write; 161 1.2.8.2 tls sc->sc_gpio_gc.gp_pin_ctl = bcm2835gpio_gpio_pin_ctl; 162 1.2.8.2 tls 163 1.2.8.2 tls gba.gba_gc = &sc->sc_gpio_gc; 164 1.2.8.2 tls gba.gba_pins = sc->sc_gpio_pins; 165 1.2.8.2 tls gba.gba_npins = maxpin - minpin + 1; 166 1.2.8.2 tls 167 1.2.8.2 tls config_found_ia(self, "gpiobus", &gba, gpiobus_print); 168 1.2.8.2 tls #else 169 1.2.8.2 tls aprint_normal_dev(sc->sc_dev, "no GPIO configured in kernel"); 170 1.2.8.2 tls #endif 171 1.2.8.2 tls } 172 1.2.8.2 tls 173 1.2.8.2 tls #if NGPIO > 0 174 1.2.8.2 tls /* GPIO support functions */ 175 1.2.8.2 tls static int 176 1.2.8.2 tls bcm2835gpio_gpio_pin_read(void *arg, int pin) 177 1.2.8.2 tls { 178 1.2.8.2 tls struct bcmgpio_softc *sc = arg; 179 1.2.8.2 tls int epin = pin + device_unit(sc->sc_dev) * 32; 180 1.2.8.2 tls uint32_t val; 181 1.2.8.2 tls int res; 182 1.2.8.2 tls 183 1.2.8.2 tls if (device_unit(sc->sc_dev) > 1) { 184 1.2.8.2 tls return 0; 185 1.2.8.2 tls } 186 1.2.8.2 tls 187 1.2.8.2 tls val = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 188 1.2.8.2 tls BCM2835_GPIO_GPLEV(epin / BCM2835_GPIO_GPLEV_PINS_PER_REGISTER)); 189 1.2.8.2 tls 190 1.2.8.2 tls res = val & (1 << (epin % BCM2835_GPIO_GPLEV_PINS_PER_REGISTER)) ? 191 1.2.8.2 tls GPIO_PIN_HIGH : GPIO_PIN_LOW; 192 1.2.8.2 tls 193 1.2.8.2 tls DPRINTF(2, ("%s: gpio_read pin %d->%d\n", device_xname(sc->sc_dev), epin, (res == GPIO_PIN_HIGH))); 194 1.2.8.2 tls 195 1.2.8.2 tls return res; 196 1.2.8.2 tls } 197 1.2.8.2 tls 198 1.2.8.2 tls static void 199 1.2.8.2 tls bcm2835gpio_gpio_pin_write(void *arg, int pin, int value) 200 1.2.8.2 tls { 201 1.2.8.2 tls struct bcmgpio_softc *sc = arg; 202 1.2.8.2 tls int epin = pin + device_unit(sc->sc_dev) * 32; 203 1.2.8.2 tls bus_size_t reg; 204 1.2.8.2 tls 205 1.2.8.2 tls if (device_unit(sc->sc_dev) > 1) { 206 1.2.8.2 tls return; 207 1.2.8.2 tls } 208 1.2.8.2 tls 209 1.2.8.2 tls if (value == GPIO_PIN_HIGH) { 210 1.2.8.2 tls reg = BCM2835_GPIO_GPSET(epin / BCM2835_GPIO_GPSET_PINS_PER_REGISTER); 211 1.2.8.2 tls } else { 212 1.2.8.2 tls reg = BCM2835_GPIO_GPCLR(epin / BCM2835_GPIO_GPCLR_PINS_PER_REGISTER); 213 1.2.8.2 tls } 214 1.2.8.2 tls 215 1.2.8.2 tls bus_space_write_4(sc->sc_iot, sc->sc_ioh, 216 1.2.8.2 tls reg, 1 << (epin % BCM2835_GPIO_GPSET_PINS_PER_REGISTER)); 217 1.2.8.2 tls DPRINTF(2, ("%s: gpio_write pin %d<-%d\n", device_xname(sc->sc_dev), epin, (value == GPIO_PIN_HIGH))); 218 1.2.8.2 tls } 219 1.2.8.2 tls 220 1.2.8.2 tls static void 221 1.2.8.2 tls bcm2835gpio_gpio_pin_ctl(void *arg, int pin, int flags) 222 1.2.8.2 tls { 223 1.2.8.2 tls struct bcmgpio_softc *sc = arg; 224 1.2.8.2 tls uint32_t cmd; 225 1.2.8.2 tls int epin = pin + device_unit(sc->sc_dev) * 32; 226 1.2.8.2 tls 227 1.2.8.2 tls if (device_unit(sc->sc_dev) > 1) { 228 1.2.8.2 tls return; 229 1.2.8.2 tls } 230 1.2.8.2 tls 231 1.2.8.2 tls DPRINTF(2, ("%s: gpio_ctl pin %d flags 0x%x\n", device_xname(sc->sc_dev), epin, flags)); 232 1.2.8.2 tls 233 1.2.8.2 tls if (flags & (GPIO_PIN_OUTPUT|GPIO_PIN_INPUT)) { 234 1.2.8.2 tls if ((flags & GPIO_PIN_INPUT) || !(flags & GPIO_PIN_OUTPUT)) { 235 1.2.8.2 tls /* for safety INPUT will overide output */ 236 1.2.8.2 tls bcm2835gpio_function_select(epin, BCM2835_GPIO_IN); 237 1.2.8.2 tls } else { 238 1.2.8.2 tls bcm2835gpio_function_select(epin, BCM2835_GPIO_OUT); 239 1.2.8.2 tls } 240 1.2.8.2 tls } 241 1.2.8.2 tls 242 1.2.8.2 tls if (flags & (GPIO_PIN_PULLUP|GPIO_PIN_PULLDOWN)) { 243 1.2.8.2 tls cmd = (flags & GPIO_PIN_PULLUP) ? 244 1.2.8.2 tls BCM2835_GPIO_GPPUD_PULLUP : BCM2835_GPIO_GPPUD_PULLDOWN; 245 1.2.8.2 tls } else { 246 1.2.8.2 tls cmd = BCM2835_GPIO_GPPUD_PULLOFF; 247 1.2.8.2 tls } 248 1.2.8.2 tls 249 1.2.8.2 tls /* set up control signal */ 250 1.2.8.2 tls bus_space_write_4(sc->sc_iot, sc->sc_ioh, 251 1.2.8.2 tls BCM2835_GPIO_GPPUD, cmd); 252 1.2.8.2 tls delay(1); /* wait 150 cycles */ 253 1.2.8.2 tls /* set clock signal */ 254 1.2.8.2 tls bus_space_write_4(sc->sc_iot, sc->sc_ioh, 255 1.2.8.2 tls BCM2835_GPIO_GPPUDCLK(device_unit(sc->sc_dev)), 256 1.2.8.2 tls 1 << (epin % BCM2835_GPIO_GPPUD_PINS_PER_REGISTER)); 257 1.2.8.2 tls delay(1); /* wait 150 cycles */ 258 1.2.8.2 tls /* reset control signal and clock */ 259 1.2.8.2 tls bus_space_write_4(sc->sc_iot, sc->sc_ioh, 260 1.2.8.2 tls BCM2835_GPIO_GPPUD, BCM2835_GPIO_GPPUD_PULLOFF); 261 1.2.8.2 tls bus_space_write_4(sc->sc_iot, sc->sc_ioh, 262 1.2.8.2 tls BCM2835_GPIO_GPPUDCLK(device_unit(sc->sc_dev)), 263 1.2.8.2 tls 0); 264 1.2.8.2 tls } 265 1.2.8.2 tls #endif /* NGPIO > 0 */ 266
Indexes created Fri Oct 03 02:09:57 GMT 2025