xref: /freebsd/sys/arm/ti/am335x/am335x_scm.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
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/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 #include <sys/kernel.h>
34 #include <sys/module.h>
35 #include <sys/sysctl.h>
36 
37 #include <machine/bus.h>
38 
39 #include <arm/ti/am335x/am335x_scm.h>
40 #include <arm/ti/ti_cpuid.h>
41 #include <arm/ti/ti_scm.h>
42 
43 #include <dev/extres/syscon/syscon.h>
44 #include "syscon_if.h"
45 
46 #define	TZ_ZEROC	2731
47 
48 struct am335x_scm_softc {
49 	int			sc_last_temp;
50 	struct sysctl_oid	*sc_temp_oid;
51 	struct syscon		*syscon;
52 };
53 
54 static int
55 am335x_scm_temp_sysctl(SYSCTL_HANDLER_ARGS)
56 {
57 	device_t dev;
58 	int i, temp;
59 	struct am335x_scm_softc *sc;
60 	uint32_t reg;
61 
62 	dev = (device_t)arg1;
63 	sc = device_get_softc(dev);
64 
65 	/* Read the temperature and convert to Kelvin. */
66 	for(i = 50; i > 0; i--) {
67 		reg = SYSCON_READ_4(sc->syscon, SCM_BGAP_CTRL);
68 		if ((reg & SCM_BGAP_EOCZ) == 0)
69 			break;
70 		DELAY(50);
71 	}
72 	if ((reg & SCM_BGAP_EOCZ) == 0) {
73 		sc->sc_last_temp =
74 		    (reg >> SCM_BGAP_TEMP_SHIFT) & SCM_BGAP_TEMP_MASK;
75 		sc->sc_last_temp *= 10;
76 	}
77 	temp = sc->sc_last_temp + TZ_ZEROC;
78 
79 	return (sysctl_handle_int(oidp, &temp, 0, req));
80 }
81 
82 static void
83 am335x_scm_identify(driver_t *driver, device_t parent)
84 {
85 	device_t child;
86 
87 	/* AM335x only. */
88 	if (ti_chip() != CHIP_AM335X)
89 		return;
90 
91 	/* Make sure we attach only once. */
92 	if (device_find_child(parent, "am335x_scm", -1) != NULL)
93 		return;
94 
95 	child = device_add_child(parent, "am335x_scm", -1);
96 	if (child == NULL)
97 		device_printf(parent, "cannot add ti_scm child\n");
98 }
99 
100 static int
101 am335x_scm_probe(device_t dev)
102 {
103 	/* Just allow the first one */
104 	if (strcmp(device_get_nameunit(dev), "am335x_scm0") != 0)
105 		return (ENXIO);
106 
107 	device_set_desc(dev, "AM335x Control Module Extension");
108 
109 	return (BUS_PROBE_DEFAULT);
110 }
111 
112 static int
113 am335x_scm_attach(device_t dev)
114 {
115 	struct am335x_scm_softc *sc;
116 	struct sysctl_ctx_list *ctx;
117 	struct sysctl_oid_list *tree;
118 	uint32_t reg;
119 	phandle_t opp_table;
120 	int err;
121 
122 	sc = device_get_softc(dev);
123 
124 	/* FIXME: For now; Go and kidnap syscon from opp-table */
125 	opp_table = OF_finddevice("/opp-table");
126 	if (opp_table == -1) {
127 		device_printf(dev, "Cant find /opp-table\n");
128 		return (ENXIO);
129 	}
130 	if (!OF_hasprop(opp_table, "syscon")) {
131 		device_printf(dev, "/opp-table missing syscon property\n");
132 		return (ENXIO);
133 	}
134 	err = syscon_get_by_ofw_property(dev, opp_table, "syscon", &sc->syscon);
135 	if (err) {
136 		device_printf(dev, "Failed to get syscon\n");
137 		return (ENXIO);
138 	}
139 
140 	/* Reset the digital outputs. */
141 	SYSCON_WRITE_4(sc->syscon, SCM_BGAP_CTRL, 0);
142 	reg = SYSCON_READ_4(sc->syscon, SCM_BGAP_CTRL);
143 	DELAY(500);
144 	/* Set continuous mode. */
145 	SYSCON_WRITE_4(sc->syscon, SCM_BGAP_CTRL, SCM_BGAP_CONTCONV);
146 	reg = SYSCON_READ_4(sc->syscon, SCM_BGAP_CTRL);
147 	DELAY(500);
148 	/* Start the ADC conversion. */
149 	reg = SCM_BGAP_CLRZ | SCM_BGAP_CONTCONV | SCM_BGAP_SOC;
150 	SYSCON_WRITE_4(sc->syscon, SCM_BGAP_CTRL, reg);
151 
152 	/* Temperature sysctl. */
153         ctx = device_get_sysctl_ctx(dev);
154 	tree = SYSCTL_CHILDREN(device_get_sysctl_tree(dev));
155 	sc->sc_temp_oid = SYSCTL_ADD_PROC(ctx, tree, OID_AUTO,
156 	    "temperature", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE,
157 	    dev, 0, am335x_scm_temp_sysctl, "IK", "Current temperature");
158 
159 	return (0);
160 }
161 
162 static int
163 am335x_scm_detach(device_t dev)
164 {
165 	struct am335x_scm_softc *sc;
166 
167 	sc = device_get_softc(dev);
168 
169 	/* Remove temperature sysctl. */
170 	if (sc->sc_temp_oid != NULL)
171 		sysctl_remove_oid(sc->sc_temp_oid, 1, 0);
172 
173 	/* Stop the bandgap ADC. */
174 	SYSCON_WRITE_4(sc->syscon, SCM_BGAP_CTRL, SCM_BGAP_BGOFF);
175 
176 	return (0);
177 }
178 
179 static device_method_t am335x_scm_methods[] = {
180 	DEVMETHOD(device_identify,	am335x_scm_identify),
181 	DEVMETHOD(device_probe,		am335x_scm_probe),
182 	DEVMETHOD(device_attach,	am335x_scm_attach),
183 	DEVMETHOD(device_detach,	am335x_scm_detach),
184 
185 	DEVMETHOD_END
186 };
187 
188 static driver_t am335x_scm_driver = {
189 	"am335x_scm",
190 	am335x_scm_methods,
191 	sizeof(struct am335x_scm_softc),
192 };
193 
194 DRIVER_MODULE(am335x_scm, ti_scm, am335x_scm_driver, 0, 0);
195 MODULE_VERSION(am335x_scm, 1);
196 MODULE_DEPEND(am335x_scm, ti_scm_syscon, 1, 1, 1);
197