1 /* $NetBSD: fdt_pwm.c,v 1.1 2018/05/06 10:33:21 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 1.1 2018/05/06 10:33:21 jmcneill Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/bus.h> 34 #include <sys/kmem.h> 35 36 #include <libfdt.h> 37 #include <dev/fdt/fdtvar.h> 38 39 struct fdtbus_pwm_controller { 40 device_t pc_dev; 41 int pc_phandle; 42 const struct fdtbus_pwm_controller_func *pc_funcs; 43 44 struct fdtbus_pwm_controller *pc_next; 45 }; 46 47 static struct fdtbus_pwm_controller *fdtbus_pc = NULL; 48 49 int 50 fdtbus_register_pwm_controller(device_t dev, int phandle, 51 const struct fdtbus_pwm_controller_func *funcs) 52 { 53 struct fdtbus_pwm_controller *pc; 54 55 pc = kmem_alloc(sizeof(*pc), KM_SLEEP); 56 pc->pc_dev = dev; 57 pc->pc_phandle = phandle; 58 pc->pc_funcs = funcs; 59 60 pc->pc_next = fdtbus_pc; 61 fdtbus_pc = pc; 62 63 return 0; 64 } 65 66 static struct fdtbus_pwm_controller * 67 fdtbus_get_pwm_controller(int phandle) 68 { 69 struct fdtbus_pwm_controller *pc; 70 71 for (pc = fdtbus_pc; pc; pc = pc->pc_next) { 72 if (pc->pc_phandle == phandle) { 73 return pc; 74 } 75 } 76 77 return NULL; 78 } 79 80 pwm_tag_t 81 fdtbus_pwm_acquire(int phandle, const char *prop) 82 { 83 return fdtbus_pwm_acquire_index(phandle, prop, 0); 84 } 85 86 pwm_tag_t 87 fdtbus_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