xref: /freebsd/sys/arm/ti/am335x/am335x_pwmss.c (revision 3fc36ee018bb836bd1796067cf4ef8683f166ebc)
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("$FreeBSD$");
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 
63 static device_probe_t am335x_pwmss_probe;
64 static device_attach_t am335x_pwmss_attach;
65 static device_detach_t am335x_pwmss_detach;
66 
67 struct am335x_pwmss_softc {
68 	struct simplebus_softc	sc_simplebus;
69 	device_t		sc_dev;
70 	clk_ident_t		sc_clk;
71 };
72 
73 static 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 
81 static int
82 am335x_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 
96 static int
97 am335x_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 
153 static int
154 am335x_pwmss_detach(device_t dev)
155 {
156 
157 	return (0);
158 }
159 
160 DEFINE_CLASS_1(am335x_pwmss, am335x_pwmss_driver, am335x_pwmss_methods,
161     sizeof(struct am335x_pwmss_softc), simplebus_driver);
162 static devclass_t am335x_pwmss_devclass;
163 DRIVER_MODULE(am335x_pwmss, simplebus, am335x_pwmss_driver, am335x_pwmss_devclass, 0, 0);
164 MODULE_VERSION(am335x_pwmss, 1);
165