sys/arm/ti/am335x/am335x_pwmss.c

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