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
56static struct ofw_compat_data compat_data[] = {
57	{ "qcom,gcc-msm8916",			1 },
58	{ NULL,					0 }
59};
60
61struct qcom_gcc_softc {
62	struct resource		*res;
63};
64
65static 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 */
74static void
75qcom_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
94static int
95qcom_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
108static int
109qcom_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
130static 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
138static driver_t qcom_gcc_driver = {
139	"qcom_gcc",
140	qcom_gcc_methods,
141	sizeof(struct qcom_gcc_softc),
142};
143
144static devclass_t qcom_gcc_devclass;
145
146EARLY_DRIVER_MODULE(qcom_gcc, simplebus, qcom_gcc_driver, qcom_gcc_devclass,
147    0, 0, BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
148MODULE_VERSION(qcom_gcc, 1);
149