xref: /freebsd/sys/arm64/qualcomm/qcom_gcc.c (revision b306c604df541dede4d0f3cc96188bbf5b6719fe)
1 /*-
2  * Copyright (c) 2018 Ruslan Bukin <br@bsdpad.com>
3  * All rights reserved.
4  *
5  * This software was developed by BAE Systems, the University of Cambridge
6  * Computer Laboratory, and Memorial University under DARPA/AFRL contract
7  * FA8650-15-C-7558 ("CADETS"), as part of the DARPA Transparent Computing
8  * (TC) research program.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/bus.h>
38 #include <sys/kthread.h>
39 #include <sys/rman.h>
40 #include <sys/kernel.h>
41 #include <sys/module.h>
42 #include <machine/bus.h>
43 
44 #include <dev/ofw/ofw_bus.h>
45 #include <dev/ofw/ofw_bus_subr.h>
46 
47 #define	GCC_QDSS_BCR			0x29000
48 #define	 GCC_QDSS_BCR_BLK_ARES		(1 << 0) /* Async software reset. */
49 #define	GCC_QDSS_CFG_AHB_CBCR		0x29008
50 #define	 AHB_CBCR_CLK_ENABLE		(1 << 0) /* AHB clk branch ctrl */
51 #define	GCC_QDSS_ETR_USB_CBCR		0x29028
52 #define	 ETR_USB_CBCR_CLK_ENABLE	(1 << 0) /* ETR USB clk branch ctrl */
53 #define	GCC_QDSS_DAP_CBCR		0x29084
54 #define	 DAP_CBCR_CLK_ENABLE		(1 << 0) /* DAP clk branch ctrl */
55 
56 static struct ofw_compat_data compat_data[] = {
57 	{ "qcom,gcc-msm8916",			1 },
58 	{ NULL,					0 }
59 };
60 
61 struct qcom_gcc_softc {
62 	struct resource		*res;
63 };
64 
65 static struct resource_spec qcom_gcc_spec[] = {
66 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
67 	{ -1, 0 }
68 };
69 
70 /*
71  * Qualcomm Debug Subsystem (QDSS)
72  * block enabling routine.
73  */
74 static void
75 qcom_qdss_enable(struct qcom_gcc_softc *sc)
76 {
77 
78 	/* Put QDSS block to reset */
79 	bus_write_4(sc->res, GCC_QDSS_BCR, GCC_QDSS_BCR_BLK_ARES);
80 
81 	/* Enable AHB clock branch */
82 	bus_write_4(sc->res, GCC_QDSS_CFG_AHB_CBCR, AHB_CBCR_CLK_ENABLE);
83 
84 	/* Enable DAP clock branch */
85 	bus_write_4(sc->res, GCC_QDSS_DAP_CBCR, DAP_CBCR_CLK_ENABLE);
86 
87 	/* Enable ETR USB clock branch */
88 	bus_write_4(sc->res, GCC_QDSS_ETR_USB_CBCR, ETR_USB_CBCR_CLK_ENABLE);
89 
90 	/* Out of reset */
91 	bus_write_4(sc->res, GCC_QDSS_BCR, 0);
92 }
93 
94 static int
95 qcom_gcc_probe(device_t dev)
96 {
97 	if (!ofw_bus_status_okay(dev))
98 		return (ENXIO);
99 
100 	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
101 		return (ENXIO);
102 
103 	device_set_desc(dev, "Qualcomm Global Clock Controller");
104 
105 	return (BUS_PROBE_DEFAULT);
106 }
107 
108 static int
109 qcom_gcc_attach(device_t dev)
110 {
111 	struct qcom_gcc_softc *sc;
112 
113 	sc = device_get_softc(dev);
114 
115 	if (bus_alloc_resources(dev, qcom_gcc_spec, &sc->res) != 0) {
116 		device_printf(dev, "cannot allocate resources for device\n");
117 		return (ENXIO);
118 	}
119 
120 	/*
121 	 * Enable debug unit.
122 	 * This is required for Coresight operation.
123 	 * This also enables USB clock branch.
124 	 */
125 	qcom_qdss_enable(sc);
126 
127 	return (0);
128 }
129 
130 static device_method_t qcom_gcc_methods[] = {
131 	/* Device interface */
132 	DEVMETHOD(device_probe,		qcom_gcc_probe),
133 	DEVMETHOD(device_attach,	qcom_gcc_attach),
134 
135 	DEVMETHOD_END
136 };
137 
138 static driver_t qcom_gcc_driver = {
139 	"qcom_gcc",
140 	qcom_gcc_methods,
141 	sizeof(struct qcom_gcc_softc),
142 };
143 
144 EARLY_DRIVER_MODULE(qcom_gcc, simplebus, qcom_gcc_driver, 0, 0,
145     BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
146 MODULE_VERSION(qcom_gcc, 1);
147