bcm2835_gpio.c revision 1.1.2.2
1 1.1.2.2 rmind /* $NetBSD: bcm2835_gpio.c,v 1.1.2.2 2014/05/18 17:44:57 rmind Exp $ */ 2 1.1.2.2 rmind 3 1.1.2.2 rmind /*- 4 1.1.2.2 rmind * Copyright (c) 2014 The NetBSD Foundation, Inc. 5 1.1.2.2 rmind * All rights reserved. 6 1.1.2.2 rmind * 7 1.1.2.2 rmind * This code is derived from software contributed to The NetBSD Foundation 8 1.1.2.2 rmind * by Frank Kardel. 9 1.1.2.2 rmind * 10 1.1.2.2 rmind * Redistribution and use in source and binary forms, with or without 11 1.1.2.2 rmind * modification, are permitted provided that the following conditions 12 1.1.2.2 rmind * are met: 13 1.1.2.2 rmind * 1. Redistributions of source code must retain the above copyright 14 1.1.2.2 rmind * notice, this list of conditions and the following disclaimer. 15 1.1.2.2 rmind * 2. Redistributions in binary form must reproduce the above copyright 16 1.1.2.2 rmind * notice, this list of conditions and the following disclaimer in the 17 1.1.2.2 rmind * documentation and/or other materials provided with the distribution. 18 1.1.2.2 rmind * 19 1.1.2.2 rmind * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 1.1.2.2 rmind * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 1.1.2.2 rmind * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 1.1.2.2 rmind * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 23 1.1.2.2 rmind * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 24 1.1.2.2 rmind * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 25 1.1.2.2 rmind * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 26 1.1.2.2 rmind * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 27 1.1.2.2 rmind * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 28 1.1.2.2 rmind * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 29 1.1.2.2 rmind * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 1.1.2.2 rmind */ 31 1.1.2.2 rmind 32 1.1.2.2 rmind #include <sys/cdefs.h> 33 1.1.2.2 rmind __KERNEL_RCSID(0, "$NetBSD: bcm2835_gpio.c,v 1.1.2.2 2014/05/18 17:44:57 rmind Exp $"); 34 1.1.2.2 rmind 35 1.1.2.2 rmind /* 36 1.1.2.2 rmind * Driver for BCM2835 GPIO 37 1.1.2.2 rmind * 38 1.1.2.2 rmind * see: http://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripherals.pdf 39 1.1.2.2 rmind */ 40 1.1.2.2 rmind 41 1.1.2.2 rmind #include "gpio.h" 42 1.1.2.2 rmind 43 1.1.2.2 rmind #include <sys/param.h> 44 1.1.2.2 rmind #include <sys/device.h> 45 1.1.2.2 rmind #include <sys/systm.h> 46 1.1.2.2 rmind #include <sys/mutex.h> 47 1.1.2.2 rmind #include <sys/bus.h> 48 1.1.2.2 rmind #include <sys/intr.h> 49 1.1.2.2 rmind #include <sys/kernel.h> 50 1.1.2.2 rmind #include <sys/gpio.h> 51 1.1.2.2 rmind #include <dev/gpio/gpiovar.h> 52 1.1.2.2 rmind 53 1.1.2.2 rmind #include <sys/bitops.h> 54 1.1.2.2 rmind 55 1.1.2.2 rmind #include <arm/broadcom/bcm_amba.h> 56 1.1.2.2 rmind #include <arm/broadcom/bcm2835reg.h> 57 1.1.2.2 rmind #include <arm/broadcom/bcm2835_gpioreg.h> 58 1.1.2.2 rmind #include <arm/broadcom/bcm2835_gpio_subr.h> 59 1.1.2.2 rmind 60 1.1.2.2 rmind /* #define BCM2835_GPIO_DEBUG */ 61 1.1.2.2 rmind #ifdef BCM2835_GPIO_DEBUG 62 1.1.2.2 rmind int bcm2835gpiodebug = 3; 63 1.1.2.2 rmind #define DPRINTF(l, x) do { if (l <= bcm2835gpiodebug) { printf x; } } while (0) 64 1.1.2.2 rmind #else 65 1.1.2.2 rmind #define DPRINTF(l, x) 66 1.1.2.2 rmind #endif 67 1.1.2.2 rmind 68 1.1.2.2 rmind struct bcmgpio_softc { 69 1.1.2.2 rmind device_t sc_dev; 70 1.1.2.2 rmind bus_space_tag_t sc_iot; 71 1.1.2.2 rmind bus_space_handle_t sc_ioh; 72 1.1.2.2 rmind struct gpio_chipset_tag sc_gpio_gc; 73 1.1.2.2 rmind gpio_pin_t sc_gpio_pins[32]; 74 1.1.2.2 rmind }; 75 1.1.2.2 rmind 76 1.1.2.2 rmind static int bcmgpio_match(device_t, cfdata_t, void *); 77 1.1.2.2 rmind static void bcmgpio_attach(device_t, device_t, void *); 78 1.1.2.2 rmind 79 1.1.2.2 rmind #if NGPIO > 0 80 1.1.2.2 rmind static int bcm2835gpio_gpio_pin_read(void *, int); 81 1.1.2.2 rmind static void bcm2835gpio_gpio_pin_write(void *, int, int); 82 1.1.2.2 rmind static void bcm2835gpio_gpio_pin_ctl(void *, int, int); 83 1.1.2.2 rmind #endif 84 1.1.2.2 rmind 85 1.1.2.2 rmind CFATTACH_DECL_NEW(bcmgpio, sizeof(struct bcmgpio_softc), 86 1.1.2.2 rmind bcmgpio_match, bcmgpio_attach, NULL, NULL); 87 1.1.2.2 rmind 88 1.1.2.2 rmind static int 89 1.1.2.2 rmind bcmgpio_match(device_t parent, cfdata_t cf, void *aux) 90 1.1.2.2 rmind { 91 1.1.2.2 rmind struct amba_attach_args * const aaa = aux; 92 1.1.2.2 rmind 93 1.1.2.2 rmind if (strcmp(aaa->aaa_name, "bcmgpio") != 0) 94 1.1.2.2 rmind return 0; 95 1.1.2.2 rmind 96 1.1.2.2 rmind return 1; 97 1.1.2.2 rmind } 98 1.1.2.2 rmind 99 1.1.2.2 rmind static void 100 1.1.2.2 rmind bcmgpio_attach(device_t parent, device_t self, void *aux) 101 1.1.2.2 rmind { 102 1.1.2.2 rmind struct bcmgpio_softc * const sc = device_private(self); 103 1.1.2.2 rmind #if NGPIO > 0 104 1.1.2.2 rmind int pin, minpin, maxpin; 105 1.1.2.2 rmind u_int func; 106 1.1.2.2 rmind struct gpiobus_attach_args gba; 107 1.1.2.2 rmind #endif 108 1.1.2.2 rmind 109 1.1.2.2 rmind sc->sc_dev = self; 110 1.1.2.2 rmind 111 1.1.2.2 rmind if (device_unit(sc->sc_dev) > 1) { 112 1.1.2.2 rmind aprint_naive(" NO GPIO\n"); 113 1.1.2.2 rmind aprint_normal(": NO GPIO\n"); 114 1.1.2.2 rmind return; 115 1.1.2.2 rmind } else if (device_unit(sc->sc_dev) == 1) { 116 1.1.2.2 rmind maxpin = 53; 117 1.1.2.2 rmind minpin = 32; 118 1.1.2.2 rmind } else { 119 1.1.2.2 rmind maxpin = 31; 120 1.1.2.2 rmind minpin = 0; 121 1.1.2.2 rmind } 122 1.1.2.2 rmind 123 1.1.2.2 rmind aprint_naive("\n"); 124 1.1.2.2 rmind aprint_normal(": GPIO [%d...%d]\n", minpin, maxpin); 125 1.1.2.2 rmind 126 1.1.2.2 rmind /* already mapped - nothing to gain from struct amba_attach_args */ 127 1.1.2.2 rmind sc->sc_iot = &bcm2835_bs_tag; 128 1.1.2.2 rmind sc->sc_ioh = BCM2835_IOPHYSTOVIRT(BCM2835_GPIO_BASE); 129 1.1.2.2 rmind 130 1.1.2.2 rmind #if NGPIO > 0 131 1.1.2.2 rmind for (pin = minpin; pin <= maxpin; pin++) { 132 1.1.2.2 rmind int epin = pin - minpin; 133 1.1.2.2 rmind 134 1.1.2.2 rmind sc->sc_gpio_pins[epin].pin_num = epin; 135 1.1.2.2 rmind /* 136 1.1.2.2 rmind * find out pins still available for GPIO 137 1.1.2.2 rmind */ 138 1.1.2.2 rmind func = bcm2835gpio_function_read(pin); 139 1.1.2.2 rmind 140 1.1.2.2 rmind if (func == BCM2835_GPIO_IN || 141 1.1.2.2 rmind func == BCM2835_GPIO_OUT) { 142 1.1.2.2 rmind sc->sc_gpio_pins[epin].pin_caps = GPIO_PIN_INPUT | 143 1.1.2.2 rmind GPIO_PIN_OUTPUT | 144 1.1.2.2 rmind GPIO_PIN_PUSHPULL | GPIO_PIN_TRISTATE | 145 1.1.2.2 rmind GPIO_PIN_PULLUP | GPIO_PIN_PULLDOWN; 146 1.1.2.2 rmind /* read initial state */ 147 1.1.2.2 rmind sc->sc_gpio_pins[epin].pin_state = 148 1.1.2.2 rmind bcm2835gpio_gpio_pin_read(sc, epin); 149 1.1.2.2 rmind DPRINTF(1, ("%s: attach pin %d\n", device_xname(sc->sc_dev), pin)); 150 1.1.2.2 rmind } else { 151 1.1.2.2 rmind sc->sc_gpio_pins[epin].pin_caps = 0; 152 1.1.2.2 rmind sc->sc_gpio_pins[epin].pin_state = 0; 153 1.1.2.2 rmind DPRINTF(1, ("%s: skip pin %d - func = 0x%x\n", device_xname(sc->sc_dev), pin, func)); 154 1.1.2.2 rmind } 155 1.1.2.2 rmind } 156 1.1.2.2 rmind 157 1.1.2.2 rmind /* create controller tag */ 158 1.1.2.2 rmind sc->sc_gpio_gc.gp_cookie = sc; 159 1.1.2.2 rmind sc->sc_gpio_gc.gp_pin_read = bcm2835gpio_gpio_pin_read; 160 1.1.2.2 rmind sc->sc_gpio_gc.gp_pin_write = bcm2835gpio_gpio_pin_write; 161 1.1.2.2 rmind sc->sc_gpio_gc.gp_pin_ctl = bcm2835gpio_gpio_pin_ctl; 162 1.1.2.2 rmind 163 1.1.2.2 rmind gba.gba_gc = &sc->sc_gpio_gc; 164 1.1.2.2 rmind gba.gba_pins = sc->sc_gpio_pins; 165 1.1.2.2 rmind gba.gba_npins = maxpin - minpin + 1; 166 1.1.2.2 rmind 167 1.1.2.2 rmind config_found_ia(self, "gpiobus", &gba, gpiobus_print); 168 1.1.2.2 rmind #else 169 1.1.2.2 rmind aprint_normal_dev(sc->sc_dev, "no GPIO configured in kernel"); 170 1.1.2.2 rmind #endif 171 1.1.2.2 rmind } 172 1.1.2.2 rmind 173 1.1.2.2 rmind #if NGPIO > 0 174 1.1.2.2 rmind /* GPIO support functions */ 175 1.1.2.2 rmind static int 176 1.1.2.2 rmind bcm2835gpio_gpio_pin_read(void *arg, int pin) 177 1.1.2.2 rmind { 178 1.1.2.2 rmind struct bcmgpio_softc *sc = arg; 179 1.1.2.2 rmind int epin = pin + device_unit(sc->sc_dev) * 32; 180 1.1.2.2 rmind uint32_t val; 181 1.1.2.2 rmind int res; 182 1.1.2.2 rmind 183 1.1.2.2 rmind if (device_unit(sc->sc_dev) > 1) { 184 1.1.2.2 rmind return 0; 185 1.1.2.2 rmind } 186 1.1.2.2 rmind 187 1.1.2.2 rmind val = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 188 1.1.2.2 rmind BCM2835_GPIO_GPLEV(epin / BCM2835_GPIO_GPLEV_PINS_PER_REGISTER)); 189 1.1.2.2 rmind 190 1.1.2.2 rmind res = val & (1 << (epin % BCM2835_GPIO_GPLEV_PINS_PER_REGISTER)) ? 191 1.1.2.2 rmind GPIO_PIN_HIGH : GPIO_PIN_LOW; 192 1.1.2.2 rmind 193 1.1.2.2 rmind DPRINTF(2, ("%s: gpio_read pin %d->%d\n", device_xname(sc->sc_dev), epin, (res == GPIO_PIN_HIGH))); 194 1.1.2.2 rmind 195 1.1.2.2 rmind return res; 196 1.1.2.2 rmind } 197 1.1.2.2 rmind 198 1.1.2.2 rmind static void 199 1.1.2.2 rmind bcm2835gpio_gpio_pin_write(void *arg, int pin, int value) 200 1.1.2.2 rmind { 201 1.1.2.2 rmind struct bcmgpio_softc *sc = arg; 202 1.1.2.2 rmind int epin = pin + device_unit(sc->sc_dev) * 32; 203 1.1.2.2 rmind bus_size_t reg; 204 1.1.2.2 rmind 205 1.1.2.2 rmind if (device_unit(sc->sc_dev) > 1) { 206 1.1.2.2 rmind return; 207 1.1.2.2 rmind } 208 1.1.2.2 rmind 209 1.1.2.2 rmind if (value == GPIO_PIN_HIGH) { 210 1.1.2.2 rmind reg = BCM2835_GPIO_GPSET(epin / BCM2835_GPIO_GPSET_PINS_PER_REGISTER); 211 1.1.2.2 rmind } else { 212 1.1.2.2 rmind reg = BCM2835_GPIO_GPCLR(epin / BCM2835_GPIO_GPCLR_PINS_PER_REGISTER); 213 1.1.2.2 rmind } 214 1.1.2.2 rmind 215 1.1.2.2 rmind bus_space_write_4(sc->sc_iot, sc->sc_ioh, 216 1.1.2.2 rmind reg, 1 << (epin % BCM2835_GPIO_GPSET_PINS_PER_REGISTER)); 217 1.1.2.2 rmind DPRINTF(2, ("%s: gpio_write pin %d<-%d\n", device_xname(sc->sc_dev), epin, (value == GPIO_PIN_HIGH))); 218 1.1.2.2 rmind } 219 1.1.2.2 rmind 220 1.1.2.2 rmind static void 221 1.1.2.2 rmind bcm2835gpio_gpio_pin_ctl(void *arg, int pin, int flags) 222 1.1.2.2 rmind { 223 1.1.2.2 rmind struct bcmgpio_softc *sc = arg; 224 1.1.2.2 rmind uint32_t cmd; 225 1.1.2.2 rmind int epin = pin + device_unit(sc->sc_dev) * 32; 226 1.1.2.2 rmind 227 1.1.2.2 rmind if (device_unit(sc->sc_dev) > 1) { 228 1.1.2.2 rmind return; 229 1.1.2.2 rmind } 230 1.1.2.2 rmind 231 1.1.2.2 rmind DPRINTF(2, ("%s: gpio_ctl pin %d flags 0x%x\n", device_xname(sc->sc_dev), epin, flags)); 232 1.1.2.2 rmind 233 1.1.2.2 rmind if (flags & (GPIO_PIN_OUTPUT|GPIO_PIN_INPUT)) { 234 1.1.2.2 rmind if ((flags & GPIO_PIN_INPUT) || !(flags & GPIO_PIN_OUTPUT)) { 235 1.1.2.2 rmind /* for safety INPUT will overide output */ 236 1.1.2.2 rmind bcm2835gpio_function_select(epin, BCM2835_GPIO_IN); 237 1.1.2.2 rmind } else { 238 1.1.2.2 rmind bcm2835gpio_function_select(epin, BCM2835_GPIO_OUT); 239 1.1.2.2 rmind } 240 1.1.2.2 rmind } 241 1.1.2.2 rmind 242 1.1.2.2 rmind if (flags & (GPIO_PIN_PULLUP|GPIO_PIN_PULLDOWN)) { 243 1.1.2.2 rmind cmd = (flags & GPIO_PIN_PULLUP) ? 244 1.1.2.2 rmind BCM2835_GPIO_GPPUD_PULLUP : BCM2835_GPIO_GPPUD_PULLDOWN; 245 1.1.2.2 rmind } else { 246 1.1.2.2 rmind cmd = BCM2835_GPIO_GPPUD_PULLOFF; 247 1.1.2.2 rmind } 248 1.1.2.2 rmind 249 1.1.2.2 rmind /* set up control signal */ 250 1.1.2.2 rmind bus_space_write_4(sc->sc_iot, sc->sc_ioh, 251 1.1.2.2 rmind BCM2835_GPIO_GPPUD, cmd); 252 1.1.2.2 rmind delay(1); /* wait 150 cycles */ 253 1.1.2.2 rmind /* set clock signal */ 254 1.1.2.2 rmind bus_space_write_4(sc->sc_iot, sc->sc_ioh, 255 1.1.2.2 rmind BCM2835_GPIO_GPPUDCLK(device_unit(sc->sc_dev)), 256 1.1.2.2 rmind 1 << (epin % BCM2835_GPIO_GPPUD_PINS_PER_REGISTER)); 257 1.1.2.2 rmind delay(1); /* wait 150 cycles */ 258 1.1.2.2 rmind /* reset control signal and clock */ 259 1.1.2.2 rmind bus_space_write_4(sc->sc_iot, sc->sc_ioh, 260 1.1.2.2 rmind BCM2835_GPIO_GPPUD, BCM2835_GPIO_GPPUD_PULLOFF); 261 1.1.2.2 rmind bus_space_write_4(sc->sc_iot, sc->sc_ioh, 262 1.1.2.2 rmind BCM2835_GPIO_GPPUDCLK(device_unit(sc->sc_dev)), 263 1.1.2.2 rmind 0); 264 1.1.2.2 rmind } 265 1.1.2.2 rmind #endif /* NGPIO > 0 */ 266
Indexes created Fri Oct 03 15:10:06 GMT 2025