am335x_scm.c revision 310856
1/*- 2 * Copyright (c) 2016 Rubicon Communications, LLC (Netgate) 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_scm.c 310856 2016-12-30 20:28:07Z 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/module.h> 35#include <sys/sysctl.h> 36 37#include <machine/bus.h> 38 39#include <arm/ti/am335x/am335x_scm.h> 40#include <arm/ti/ti_cpuid.h> 41#include <arm/ti/ti_scm.h> 42 43#define TZ_ZEROC 2731 44 45struct am335x_scm_softc { 46 int sc_last_temp; 47 struct sysctl_oid *sc_temp_oid; 48}; 49 50static int 51am335x_scm_temp_sysctl(SYSCTL_HANDLER_ARGS) 52{ 53 device_t dev; 54 int i, temp; 55 struct am335x_scm_softc *sc; 56 uint32_t reg; 57 58 dev = (device_t)arg1; 59 sc = device_get_softc(dev); 60 61 /* Read the temperature and convert to Kelvin. */ 62 for(i = 50; i > 0; i--) { 63 ti_scm_reg_read_4(SCM_BGAP_CTRL, ®); 64 if ((reg & SCM_BGAP_EOCZ) == 0) 65 break; 66 DELAY(50); 67 } 68 if ((reg & SCM_BGAP_EOCZ) == 0) { 69 sc->sc_last_temp = 70 (reg >> SCM_BGAP_TEMP_SHIFT) & SCM_BGAP_TEMP_MASK; 71 sc->sc_last_temp *= 10; 72 } 73 temp = sc->sc_last_temp + TZ_ZEROC; 74 75 return (sysctl_handle_int(oidp, &temp, 0, req)); 76} 77 78static void 79am335x_scm_identify(driver_t *driver, device_t parent) 80{ 81 device_t child; 82 83 /* AM335x only. */ 84 if (ti_chip() != CHIP_AM335X) 85 return; 86 87 /* Make sure we attach only once. */ 88 if (device_find_child(parent, "am335x_scm", -1) != NULL) 89 return; 90 91 child = device_add_child(parent, "am335x_scm", -1); 92 if (child == NULL) 93 device_printf(parent, "cannot add ti_scm child\n"); 94} 95 96static int 97am335x_scm_probe(device_t dev) 98{ 99 100 device_set_desc(dev, "AM335x Control Module Extension"); 101 102 return (BUS_PROBE_DEFAULT); 103} 104 105static int 106am335x_scm_attach(device_t dev) 107{ 108 struct am335x_scm_softc *sc; 109 struct sysctl_ctx_list *ctx; 110 struct sysctl_oid_list *tree; 111 uint32_t reg; 112 113 /* Set ADC to continous mode, clear output reset. */ 114 reg = SCM_BGAP_CLRZ | SCM_BGAP_CONTCONV; 115 ti_scm_reg_write_4(SCM_BGAP_CTRL, reg); 116 /* Flush write. */ 117 ti_scm_reg_read_4(SCM_BGAP_CTRL, ®); 118 /* Start the ADC conversion. */ 119 reg = SCM_BGAP_CLRZ | SCM_BGAP_CONTCONV | SCM_BGAP_SOC; 120 ti_scm_reg_write_4(SCM_BGAP_CTRL, reg); 121 122 /* Temperature sysctl. */ 123 sc = device_get_softc(dev); 124 ctx = device_get_sysctl_ctx(dev); 125 tree = SYSCTL_CHILDREN(device_get_sysctl_tree(dev)); 126 sc->sc_temp_oid = SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, 127 "temperature", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, 128 dev, 0, am335x_scm_temp_sysctl, "IK", "Current temperature"); 129 130 return (0); 131} 132 133static int 134am335x_scm_detach(device_t dev) 135{ 136 struct am335x_scm_softc *sc; 137 138 sc = device_get_softc(dev); 139 140 /* Remove temperature sysctl. */ 141 if (sc->sc_temp_oid != NULL) 142 sysctl_remove_oid(sc->sc_temp_oid, 1, 0); 143 144 /* Stop the bandgap ADC. */ 145 ti_scm_reg_write_4(SCM_BGAP_CTRL, SCM_BGAP_BGOFF); 146 147 return (0); 148} 149 150static device_method_t am335x_scm_methods[] = { 151 DEVMETHOD(device_identify, am335x_scm_identify), 152 DEVMETHOD(device_probe, am335x_scm_probe), 153 DEVMETHOD(device_attach, am335x_scm_attach), 154 DEVMETHOD(device_detach, am335x_scm_detach), 155 156 DEVMETHOD_END 157}; 158 159static driver_t am335x_scm_driver = { 160 "am335x_scm", 161 am335x_scm_methods, 162 sizeof(struct am335x_scm_softc), 163}; 164 165static devclass_t am335x_scm_devclass; 166 167DRIVER_MODULE(am335x_scm, ti_scm, am335x_scm_driver, am335x_scm_devclass, 0, 0); 168MODULE_VERSION(am335x_scm, 1); 169MODULE_DEPEND(am335x_scm, ti_scm, 1, 1, 1); 170