xref: /freebsd/sys/arm/ti/am335x/am335x_scm.c (revision 1db64f89363c97858961c4df0b7d02f3223723cf)
1 /*-
2  * Copyright (c) 2016 Rubicon Communications, LLC (Netgate)
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/param.h>
28 #include <sys/systm.h>
29 #include <sys/bus.h>
30 #include <sys/kernel.h>
31 #include <sys/module.h>
32 #include <sys/sysctl.h>
33 
34 #include <machine/bus.h>
35 
36 #include <arm/ti/am335x/am335x_scm.h>
37 #include <arm/ti/ti_cpuid.h>
38 #include <arm/ti/ti_scm.h>
39 
40 #include <dev/extres/syscon/syscon.h>
41 #include "syscon_if.h"
42 
43 #define	TZ_ZEROC	2731
44 
45 struct am335x_scm_softc {
46 	int			sc_last_temp;
47 	struct sysctl_oid	*sc_temp_oid;
48 	struct syscon		*syscon;
49 };
50 
51 static int
52 am335x_scm_temp_sysctl(SYSCTL_HANDLER_ARGS)
53 {
54 	device_t dev;
55 	int i, temp;
56 	struct am335x_scm_softc *sc;
57 	uint32_t reg;
58 
59 	dev = (device_t)arg1;
60 	sc = device_get_softc(dev);
61 
62 	/* Read the temperature and convert to Kelvin. */
63 	for(i = 50; i > 0; i--) {
64 		reg = SYSCON_READ_4(sc->syscon, SCM_BGAP_CTRL);
65 		if ((reg & SCM_BGAP_EOCZ) == 0)
66 			break;
67 		DELAY(50);
68 	}
69 	if ((reg & SCM_BGAP_EOCZ) == 0) {
70 		sc->sc_last_temp =
71 		    (reg >> SCM_BGAP_TEMP_SHIFT) & SCM_BGAP_TEMP_MASK;
72 		sc->sc_last_temp *= 10;
73 	}
74 	temp = sc->sc_last_temp + TZ_ZEROC;
75 
76 	return (sysctl_handle_int(oidp, &temp, 0, req));
77 }
78 
79 static void
80 am335x_scm_identify(driver_t *driver, device_t parent)
81 {
82 	device_t child;
83 
84 	/* AM335x only. */
85 	if (ti_chip() != CHIP_AM335X)
86 		return;
87 
88 	/* Make sure we attach only once. */
89 	if (device_find_child(parent, "am335x_scm", -1) != NULL)
90 		return;
91 
92 	child = device_add_child(parent, "am335x_scm", -1);
93 	if (child == NULL)
94 		device_printf(parent, "cannot add ti_scm child\n");
95 }
96 
97 static int
98 am335x_scm_probe(device_t dev)
99 {
100 	/* Just allow the first one */
101 	if (strcmp(device_get_nameunit(dev), "am335x_scm0") != 0)
102 		return (ENXIO);
103 
104 	device_set_desc(dev, "AM335x Control Module Extension");
105 
106 	return (BUS_PROBE_DEFAULT);
107 }
108 
109 static int
110 am335x_scm_attach(device_t dev)
111 {
112 	struct am335x_scm_softc *sc;
113 	struct sysctl_ctx_list *ctx;
114 	struct sysctl_oid_list *tree;
115 	uint32_t reg;
116 	phandle_t opp_table;
117 	int err;
118 
119 	sc = device_get_softc(dev);
120 
121 	/* FIXME: For now; Go and kidnap syscon from opp-table */
122 	opp_table = OF_finddevice("/opp-table");
123 	if (opp_table == -1) {
124 		device_printf(dev, "Cant find /opp-table\n");
125 		return (ENXIO);
126 	}
127 	if (!OF_hasprop(opp_table, "syscon")) {
128 		device_printf(dev, "/opp-table missing syscon property\n");
129 		return (ENXIO);
130 	}
131 	err = syscon_get_by_ofw_property(dev, opp_table, "syscon", &sc->syscon);
132 	if (err) {
133 		device_printf(dev, "Failed to get syscon\n");
134 		return (ENXIO);
135 	}
136 
137 	/* Reset the digital outputs. */
138 	SYSCON_WRITE_4(sc->syscon, SCM_BGAP_CTRL, 0);
139 	reg = SYSCON_READ_4(sc->syscon, SCM_BGAP_CTRL);
140 	DELAY(500);
141 	/* Set continuous mode. */
142 	SYSCON_WRITE_4(sc->syscon, SCM_BGAP_CTRL, SCM_BGAP_CONTCONV);
143 	reg = SYSCON_READ_4(sc->syscon, SCM_BGAP_CTRL);
144 	DELAY(500);
145 	/* Start the ADC conversion. */
146 	reg = SCM_BGAP_CLRZ | SCM_BGAP_CONTCONV | SCM_BGAP_SOC;
147 	SYSCON_WRITE_4(sc->syscon, SCM_BGAP_CTRL, reg);
148 
149 	/* Temperature sysctl. */
150         ctx = device_get_sysctl_ctx(dev);
151 	tree = SYSCTL_CHILDREN(device_get_sysctl_tree(dev));
152 	sc->sc_temp_oid = SYSCTL_ADD_PROC(ctx, tree, OID_AUTO,
153 	    "temperature", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE,
154 	    dev, 0, am335x_scm_temp_sysctl, "IK", "Current temperature");
155 
156 	return (0);
157 }
158 
159 static int
160 am335x_scm_detach(device_t dev)
161 {
162 	struct am335x_scm_softc *sc;
163 
164 	sc = device_get_softc(dev);
165 
166 	/* Remove temperature sysctl. */
167 	if (sc->sc_temp_oid != NULL)
168 		sysctl_remove_oid(sc->sc_temp_oid, 1, 0);
169 
170 	/* Stop the bandgap ADC. */
171 	SYSCON_WRITE_4(sc->syscon, SCM_BGAP_CTRL, SCM_BGAP_BGOFF);
172 
173 	return (0);
174 }
175 
176 static device_method_t am335x_scm_methods[] = {
177 	DEVMETHOD(device_identify,	am335x_scm_identify),
178 	DEVMETHOD(device_probe,		am335x_scm_probe),
179 	DEVMETHOD(device_attach,	am335x_scm_attach),
180 	DEVMETHOD(device_detach,	am335x_scm_detach),
181 
182 	DEVMETHOD_END
183 };
184 
185 static driver_t am335x_scm_driver = {
186 	"am335x_scm",
187 	am335x_scm_methods,
188 	sizeof(struct am335x_scm_softc),
189 };
190 
191 DRIVER_MODULE(am335x_scm, ti_scm, am335x_scm_driver, 0, 0);
192 MODULE_VERSION(am335x_scm, 1);
193 MODULE_DEPEND(am335x_scm, ti_scm_syscon, 1, 1, 1);
194