am335x_pwmss.c revision 303772 
1/*-
2 * Copyright (c) 2013 Oleksandr Tymoshenko <gonzo@freebsd.org>
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: stable/11/sys/arm/ti/am335x/am335x_pwmss.c 303772 2016-08-05 16:32:09Z loos $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/bus.h>
33#include <sys/kernel.h>
34#include <sys/limits.h>
35#include <sys/lock.h>
36#include <sys/module.h>
37#include <sys/mutex.h>
38#include <sys/resource.h>
39#include <sys/rman.h>
40#include <sys/sysctl.h>
41
42#include <machine/bus.h>
43
44#include <dev/fdt/fdt_common.h>
45#include <dev/fdt/simplebus.h>
46#include <dev/ofw/openfirm.h>
47#include <dev/ofw/ofw_bus.h>
48#include <dev/ofw/ofw_bus_subr.h>
49
50#include <arm/ti/ti_prcm.h>
51#include <arm/ti/ti_hwmods.h>
52#include <arm/ti/ti_scm.h>
53
54#include "am335x_pwm.h"
55#include "am335x_scm.h"
56
57#define	PWMSS_IDVER		0x00
58#define	PWMSS_SYSCONFIG		0x04
59#define	PWMSS_CLKCONFIG		0x08
60#define		CLKCONFIG_EPWMCLK_EN	(1 << 8)
61#define	PWMSS_CLKSTATUS		0x0C
62
63static device_probe_t am335x_pwmss_probe;
64static device_attach_t am335x_pwmss_attach;
65static device_detach_t am335x_pwmss_detach;
66
67struct am335x_pwmss_softc {
68	struct simplebus_softc	sc_simplebus;
69	device_t		sc_dev;
70	clk_ident_t		sc_clk;
71};
72
73static device_method_t am335x_pwmss_methods[] = {
74	DEVMETHOD(device_probe,		am335x_pwmss_probe),
75	DEVMETHOD(device_attach,	am335x_pwmss_attach),
76	DEVMETHOD(device_detach,	am335x_pwmss_detach),
77
78	DEVMETHOD_END
79};
80
81static int
82am335x_pwmss_probe(device_t dev)
83{
84
85	if (!ofw_bus_status_okay(dev))
86		return (ENXIO);
87
88	if (!ofw_bus_is_compatible(dev, "ti,am33xx-pwmss"))
89		return (ENXIO);
90
91	device_set_desc(dev, "AM335x PWM");
92
93	return (BUS_PROBE_DEFAULT);
94}
95
96static int
97am335x_pwmss_attach(device_t dev)
98{
99	struct am335x_pwmss_softc *sc;
100	uint32_t reg, id;
101	phandle_t node;
102
103	sc = device_get_softc(dev);
104	sc->sc_dev = dev;
105
106	sc->sc_clk = ti_hwmods_get_clock(dev);
107	if (sc->sc_clk == INVALID_CLK_IDENT) {
108		device_printf(dev, "failed to get device id based on ti,hwmods\n");
109		return (EINVAL);
110	}
111
112	ti_prcm_clk_enable(sc->sc_clk);
113	ti_scm_reg_read_4(SCM_PWMSS_CTRL, &reg);
114	switch (sc->sc_clk) {
115		case PWMSS0_CLK:
116			id = 0;
117			break;
118		case PWMSS1_CLK:
119			id = 1;
120			break;
121
122		case PWMSS2_CLK:
123			id = 2;
124			break;
125		default:
126			device_printf(dev, "unknown pwmss clock id: %d\n", sc->sc_clk);
127			return (EINVAL);
128	}
129	reg |= (1 << id);
130	ti_scm_reg_write_4(SCM_PWMSS_CTRL, reg);
131
132	node = ofw_bus_get_node(dev);
133
134	if (node == -1)
135		return (ENXIO);
136
137	simplebus_init(dev, node);
138
139	/*
140	 * Allow devices to identify.
141	 */
142	bus_generic_probe(dev);
143
144	/*
145	 * Now walk the OFW tree and attach top-level devices.
146	 */
147	for (node = OF_child(node); node > 0; node = OF_peer(node))
148		simplebus_add_device(dev, node, 0, NULL, -1, NULL);
149
150	return (bus_generic_attach(dev));
151}
152
153static int
154am335x_pwmss_detach(device_t dev)
155{
156
157	return (0);
158}
159
160DEFINE_CLASS_1(am335x_pwmss, am335x_pwmss_driver, am335x_pwmss_methods,
161    sizeof(struct am335x_pwmss_softc), simplebus_driver);
162static devclass_t am335x_pwmss_devclass;
163DRIVER_MODULE(am335x_pwmss, simplebus, am335x_pwmss_driver, am335x_pwmss_devclass, 0, 0);
164MODULE_VERSION(am335x_pwmss, 1);
165