1 /* $NetBSD: mmc_pwrseq_emmc.c,v 1.2 2021/01/27 03:10:21 thorpej 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 1.2 2021/01/27 03:10:21 thorpej 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 struct device_compatible_entry compat_data[] = {
44 { .compat = "mmc-pwrseq-emmc" },
45 DEVICE_COMPAT_EOL
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
mmcpwrseq_emmc_reset(device_t dev)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
mmcpwrseq_emmc_match(device_t parent,cfdata_t cf,void * aux)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_compatible_match(faa->faa_phandle, compat_data);
75 }
76
77 static void
mmcpwrseq_emmc_attach(device_t parent,device_t self,void * aux)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
mmcpwrseq_emmc_detach(device_t self,int flags)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