1 /* $NetBSD: fdt_dma.c,v 1.4 2019/02/27 16:56:00 jakllsch Exp $ */
2
3 /*-
4 * Copyright (c) 2015 Jared D. 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_dma.c,v 1.4 2019/02/27 16:56:00 jakllsch 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
40 struct fdtbus_dma_controller {
41 device_t dma_dev;
42 int dma_phandle;
43 const struct fdtbus_dma_controller_func *dma_funcs;
44
45 LIST_ENTRY(fdtbus_dma_controller) dma_next;
46 };
47
48 static LIST_HEAD(, fdtbus_dma_controller) fdtbus_dma_controllers =
49 LIST_HEAD_INITIALIZER(fdtbus_dma_controllers);
50
51 int
fdtbus_register_dma_controller(device_t dev,int phandle,const struct fdtbus_dma_controller_func * funcs)52 fdtbus_register_dma_controller(device_t dev, int phandle,
53 const struct fdtbus_dma_controller_func *funcs)
54 {
55 struct fdtbus_dma_controller *dma;
56
57 dma = kmem_alloc(sizeof(*dma), KM_SLEEP);
58 dma->dma_dev = dev;
59 dma->dma_phandle = phandle;
60 dma->dma_funcs = funcs;
61
62 LIST_INSERT_HEAD(&fdtbus_dma_controllers, dma, dma_next);
63
64 return 0;
65 }
66
67 static struct fdtbus_dma_controller *
fdtbus_get_dma_controller(int phandle)68 fdtbus_get_dma_controller(int phandle)
69 {
70 struct fdtbus_dma_controller *dma;
71
72 LIST_FOREACH(dma, &fdtbus_dma_controllers, dma_next) {
73 if (dma->dma_phandle == phandle)
74 return dma;
75 }
76
77 return NULL;
78 }
79
80 struct fdtbus_dma *
fdtbus_dma_get_index(int phandle,u_int index,void (* cb)(void *),void * cbarg)81 fdtbus_dma_get_index(int phandle, u_int index, void (*cb)(void *), void *cbarg)
82 {
83 struct fdtbus_dma_controller *dc;
84 struct fdtbus_dma *dma = NULL;
85 void *dma_priv = NULL;
86 uint32_t *dmas = NULL;
87 uint32_t *p;
88 u_int n, dma_cells;
89 int len, resid;
90
91 len = OF_getproplen(phandle, "dmas");
92 if (len <= 0)
93 return NULL;
94
95 dmas = kmem_alloc(len, KM_SLEEP);
96 if (OF_getprop(phandle, "dmas", dmas, len) != len) {
97 kmem_free(dmas, len);
98 return NULL;
99 }
100
101 p = dmas;
102 for (n = 0, resid = len; resid > 0; n++) {
103 const int dc_phandle =
104 fdtbus_get_phandle_from_native(be32toh(p[0]));
105 if (of_getprop_uint32(dc_phandle, "#dma-cells", &dma_cells))
106 break;
107 if (n == index) {
108 dc = fdtbus_get_dma_controller(dc_phandle);
109 if (dc == NULL)
110 goto done;
111 dma_priv = dc->dma_funcs->acquire(dc->dma_dev,
112 dma_cells > 0 ? &p[1] : NULL, dma_cells * 4,
113 cb, cbarg);
114 if (dma_priv) {
115 dma = kmem_alloc(sizeof(*dma), KM_SLEEP);
116 dma->dma_dc = dc;
117 dma->dma_priv = dma_priv;
118 }
119 break;
120 }
121 resid -= (dma_cells + 1) * 4;
122 p += dma_cells + 1;
123 }
124
125 done:
126 if (dmas)
127 kmem_free(dmas, len);
128
129 return dma;
130 }
131
132 struct fdtbus_dma *
fdtbus_dma_get(int phandle,const char * name,void (* cb)(void *),void * cbarg)133 fdtbus_dma_get(int phandle, const char *name, void (*cb)(void *), void *cbarg)
134 {
135 u_int index;
136 int err;
137
138 err = fdtbus_get_index(phandle, "dma-names", name, &index);
139 if (err != 0)
140 return NULL;
141
142 return fdtbus_dma_get_index(phandle, index, cb, cbarg);
143 }
144
145 void
fdtbus_dma_put(struct fdtbus_dma * dma)146 fdtbus_dma_put(struct fdtbus_dma *dma)
147 {
148 struct fdtbus_dma_controller *dc = dma->dma_dc;
149
150 dc->dma_funcs->release(dc->dma_dev, dma->dma_priv);
151 kmem_free(dma, sizeof(*dma));
152 }
153
154 int
fdtbus_dma_transfer(struct fdtbus_dma * dma,struct fdtbus_dma_req * req)155 fdtbus_dma_transfer(struct fdtbus_dma *dma, struct fdtbus_dma_req *req)
156 {
157 struct fdtbus_dma_controller *dc = dma->dma_dc;
158
159 return dc->dma_funcs->transfer(dc->dma_dev, dma->dma_priv, req);
160 }
161
162 void
fdtbus_dma_halt(struct fdtbus_dma * dma)163 fdtbus_dma_halt(struct fdtbus_dma *dma)
164 {
165 struct fdtbus_dma_controller *dc = dma->dma_dc;
166
167 return dc->dma_funcs->halt(dc->dma_dev, dma->dma_priv);
168 }
169