1/* $NetBSD: fdt_pwm.c,v 1.2 2018/06/30 20:34:43 jmcneill Exp $ */ 2 3/*- 4 * Copyright (c) 2018 Jared McNeill <jmcneill@invisible.ca> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29#include <sys/cdefs.h> 30__KERNEL_RCSID(0, "$NetBSD: fdt_pwm.c,v 1.2 2018/06/30 20:34:43 jmcneill Exp $"); 31 32#include <sys/param.h> 33#include <sys/bus.h> 34#include <sys/kmem.h> 35#include <sys/queue.h> 36 37#include <libfdt.h> 38#include <dev/fdt/fdtvar.h> 39 40struct fdtbus_pwm_controller { 41 device_t pc_dev; 42 int pc_phandle; 43 const struct fdtbus_pwm_controller_func *pc_funcs; 44 45 LIST_ENTRY(fdtbus_pwm_controller) pc_next; 46}; 47 48static LIST_HEAD(, fdtbus_pwm_controller) fdtbus_pwm_controllers = 49 LIST_HEAD_INITIALIZER(fdtbus_pwm_controllers); 50 51int 52fdtbus_register_pwm_controller(device_t dev, int phandle, 53 const struct fdtbus_pwm_controller_func *funcs) 54{ 55 struct fdtbus_pwm_controller *pc; 56 57 pc = kmem_alloc(sizeof(*pc), KM_SLEEP); 58 pc->pc_dev = dev; 59 pc->pc_phandle = phandle; 60 pc->pc_funcs = funcs; 61 62 LIST_INSERT_HEAD(&fdtbus_pwm_controllers, pc, pc_next); 63 64 return 0; 65} 66 67static struct fdtbus_pwm_controller * 68fdtbus_get_pwm_controller(int phandle) 69{ 70 struct fdtbus_pwm_controller *pc; 71 72 LIST_FOREACH(pc, &fdtbus_pwm_controllers, pc_next) { 73 if (pc->pc_phandle == phandle) 74 return pc; 75 } 76 77 return NULL; 78} 79 80pwm_tag_t 81fdtbus_pwm_acquire(int phandle, const char *prop) 82{ 83 return fdtbus_pwm_acquire_index(phandle, prop, 0); 84} 85 86pwm_tag_t 87fdtbus_pwm_acquire_index(int phandle, const char *prop, int index) 88{ 89 struct fdtbus_pwm_controller *pc; 90 const uint32_t *pwms, *p; 91 u_int n, pwm_cells; 92 int len, resid; 93 94 pwms = fdtbus_get_prop(phandle, prop, &len); 95 if (pwms == NULL) 96 return NULL; 97 98 p = pwms; 99 for (n = 0, resid = len; resid > 0; n++) { 100 const int pc_phandle = 101 fdtbus_get_phandle_from_native(be32toh(p[0])); 102 if (of_getprop_uint32(pc_phandle, "#pwm-cells", &pwm_cells)) 103 break; 104 if (n == index) { 105 pc = fdtbus_get_pwm_controller(pc_phandle); 106 if (pc == NULL) 107 return NULL; 108 return pc->pc_funcs->get_tag(pc->pc_dev, 109 &p[0], (pwm_cells + 1) * 4); 110 } 111 resid -= (pwm_cells + 1) * 4; 112 p += pwm_cells + 1; 113 } 114 115 return NULL; 116} 117