1 /* $NetBSD: mmc_pwrseq_emmc.c,v 1.1 2019/03/03 12:54:07 jmcneill Exp $ */ 2 3 /*- 4 * Copyright (c) 2019 Jared McNeill <jmcneill@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: mmc_pwrseq_emmc.c,v 1.1 2019/03/03 12:54:07 jmcneill Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/kernel.h> 34 #include <sys/device.h> 35 #include <sys/systm.h> 36 #include <sys/proc.h> 37 #include <sys/gpio.h> 38 39 #include <dev/fdt/fdtvar.h> 40 41 #define MMCPWRSEQ_MAX_PINS 32 42 43 static const char * const compatible[] = { 44 "mmc-pwrseq-emmc", 45 NULL 46 }; 47 48 struct mmcpwrseq_emmc_softc { 49 device_t sc_dev; 50 int sc_phandle; 51 struct fdtbus_gpio_pin *sc_pin; 52 }; 53 54 static void 55 mmcpwrseq_emmc_reset(device_t dev) 56 { 57 struct mmcpwrseq_emmc_softc * const sc = device_private(dev); 58 59 fdtbus_gpio_write(sc->sc_pin, 1); 60 delay(1); 61 fdtbus_gpio_write(sc->sc_pin, 0); 62 delay(200); 63 } 64 65 static const struct fdtbus_mmc_pwrseq_func mmcpwrseq_emmc_funcs = { 66 .reset = mmcpwrseq_emmc_reset, 67 }; 68 69 static int 70 mmcpwrseq_emmc_match(device_t parent, cfdata_t cf, void *aux) 71 { 72 struct fdt_attach_args * const faa = aux; 73 74 return of_match_compatible(faa->faa_phandle, compatible); 75 } 76 77 static void 78 mmcpwrseq_emmc_attach(device_t parent, device_t self, void *aux) 79 { 80 struct mmcpwrseq_emmc_softc * const sc = device_private(self); 81 struct fdt_attach_args * const faa = aux; 82 const int phandle = faa->faa_phandle; 83 84 sc->sc_dev = self; 85 sc->sc_phandle = phandle; 86 87 sc->sc_pin = fdtbus_gpio_acquire_index(phandle, "reset-gpios", 0, GPIO_PIN_OUTPUT); 88 if (sc->sc_pin == NULL) { 89 aprint_error(": couldn't get reset GPIO\n"); 90 return; 91 } 92 93 aprint_naive("\n"); 94 aprint_normal(": eMMC hardware reset provider\n"); 95 96 fdtbus_register_mmc_pwrseq(self, phandle, &mmcpwrseq_emmc_funcs); 97 } 98 99 static int 100 mmcpwrseq_emmc_detach(device_t self, int flags) 101 { 102 struct mmcpwrseq_emmc_softc * const sc = device_private(self); 103 104 if (sc->sc_pin != NULL) 105 mmcpwrseq_emmc_reset(self); 106 107 return 0; 108 } 109 110 CFATTACH_DECL_NEW(mmcpwrseq_emmc, sizeof(struct mmcpwrseq_emmc_softc), 111 mmcpwrseq_emmc_match, mmcpwrseq_emmc_attach, mmcpwrseq_emmc_detach, NULL); 112