Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 1 | /* |
| 2 | * Device tree helpers for DMA request / controller |
| 3 | * |
| 4 | * Based on of_gpio.c |
| 5 | * |
| 6 | * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/ |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License version 2 as |
| 10 | * published by the Free Software Foundation. |
| 11 | */ |
| 12 | |
| 13 | #include <linux/device.h> |
| 14 | #include <linux/err.h> |
| 15 | #include <linux/module.h> |
Lars-Peter Clausen | de61608 | 2013-04-19 11:42:14 +0200 | [diff] [blame] | 16 | #include <linux/mutex.h> |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 17 | #include <linux/slab.h> |
| 18 | #include <linux/of.h> |
| 19 | #include <linux/of_dma.h> |
| 20 | |
| 21 | static LIST_HEAD(of_dma_list); |
Lars-Peter Clausen | de61608 | 2013-04-19 11:42:14 +0200 | [diff] [blame] | 22 | static DEFINE_MUTEX(of_dma_lock); |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 23 | |
| 24 | /** |
Lars-Peter Clausen | de61608 | 2013-04-19 11:42:14 +0200 | [diff] [blame] | 25 | * of_dma_find_controller - Get a DMA controller in DT DMA helpers list |
Jon Hunter | 9743a3b | 2012-10-11 14:43:01 -0500 | [diff] [blame] | 26 | * @dma_spec: pointer to DMA specifier as found in the device tree |
| 27 | * |
| 28 | * Finds a DMA controller with matching device node and number for dma cells |
Lars-Peter Clausen | de61608 | 2013-04-19 11:42:14 +0200 | [diff] [blame] | 29 | * in a list of registered DMA controllers. If a match is found a valid pointer |
| 30 | * to the DMA data stored is retuned. A NULL pointer is returned if no match is |
| 31 | * found. |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 32 | */ |
Lars-Peter Clausen | de61608 | 2013-04-19 11:42:14 +0200 | [diff] [blame] | 33 | static struct of_dma *of_dma_find_controller(struct of_phandle_args *dma_spec) |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 34 | { |
| 35 | struct of_dma *ofdma; |
| 36 | |
Jon Hunter | 9743a3b | 2012-10-11 14:43:01 -0500 | [diff] [blame] | 37 | list_for_each_entry(ofdma, &of_dma_list, of_dma_controllers) |
Lars-Peter Clausen | 8552bb4 | 2013-04-22 10:33:33 +0200 | [diff] [blame] | 38 | if (ofdma->of_node == dma_spec->np) |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 39 | return ofdma; |
Jon Hunter | 9743a3b | 2012-10-11 14:43:01 -0500 | [diff] [blame] | 40 | |
| 41 | pr_debug("%s: can't find DMA controller %s\n", __func__, |
| 42 | dma_spec->np->full_name); |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 43 | |
| 44 | return NULL; |
| 45 | } |
| 46 | |
| 47 | /** |
Peter Ujfalusi | 56f13c0 | 2015-04-09 12:35:47 +0300 | [diff] [blame^] | 48 | * of_dma_router_xlate - translation function for router devices |
| 49 | * @dma_spec: pointer to DMA specifier as found in the device tree |
| 50 | * @of_dma: pointer to DMA controller data (router information) |
| 51 | * |
| 52 | * The function creates new dma_spec to be passed to the router driver's |
| 53 | * of_dma_route_allocate() function to prepare a dma_spec which will be used |
| 54 | * to request channel from the real DMA controller. |
| 55 | */ |
| 56 | static struct dma_chan *of_dma_router_xlate(struct of_phandle_args *dma_spec, |
| 57 | struct of_dma *ofdma) |
| 58 | { |
| 59 | struct dma_chan *chan; |
| 60 | struct of_dma *ofdma_target; |
| 61 | struct of_phandle_args dma_spec_target; |
| 62 | void *route_data; |
| 63 | |
| 64 | /* translate the request for the real DMA controller */ |
| 65 | memcpy(&dma_spec_target, dma_spec, sizeof(dma_spec_target)); |
| 66 | route_data = ofdma->of_dma_route_allocate(&dma_spec_target, ofdma); |
| 67 | if (IS_ERR(route_data)) |
| 68 | return NULL; |
| 69 | |
| 70 | ofdma_target = of_dma_find_controller(&dma_spec_target); |
| 71 | if (!ofdma_target) |
| 72 | return NULL; |
| 73 | |
| 74 | chan = ofdma_target->of_dma_xlate(&dma_spec_target, ofdma_target); |
| 75 | if (chan) { |
| 76 | chan->router = ofdma->dma_router; |
| 77 | chan->route_data = route_data; |
| 78 | } else { |
| 79 | ofdma->dma_router->route_free(ofdma->dma_router->dev, |
| 80 | route_data); |
| 81 | } |
| 82 | |
| 83 | /* |
| 84 | * Need to put the node back since the ofdma->of_dma_route_allocate |
| 85 | * has taken it for generating the new, translated dma_spec |
| 86 | */ |
| 87 | of_node_put(dma_spec_target.np); |
| 88 | return chan; |
| 89 | } |
| 90 | |
| 91 | /** |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 92 | * of_dma_controller_register - Register a DMA controller to DT DMA helpers |
| 93 | * @np: device node of DMA controller |
| 94 | * @of_dma_xlate: translation function which converts a phandle |
| 95 | * arguments list into a dma_chan structure |
| 96 | * @data pointer to controller specific data to be used by |
| 97 | * translation function |
| 98 | * |
| 99 | * Returns 0 on success or appropriate errno value on error. |
| 100 | * |
| 101 | * Allocated memory should be freed with appropriate of_dma_controller_free() |
| 102 | * call. |
| 103 | */ |
| 104 | int of_dma_controller_register(struct device_node *np, |
| 105 | struct dma_chan *(*of_dma_xlate) |
| 106 | (struct of_phandle_args *, struct of_dma *), |
| 107 | void *data) |
| 108 | { |
| 109 | struct of_dma *ofdma; |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 110 | |
| 111 | if (!np || !of_dma_xlate) { |
| 112 | pr_err("%s: not enough information provided\n", __func__); |
| 113 | return -EINVAL; |
| 114 | } |
| 115 | |
| 116 | ofdma = kzalloc(sizeof(*ofdma), GFP_KERNEL); |
| 117 | if (!ofdma) |
| 118 | return -ENOMEM; |
| 119 | |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 120 | ofdma->of_node = np; |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 121 | ofdma->of_dma_xlate = of_dma_xlate; |
| 122 | ofdma->of_dma_data = data; |
| 123 | |
| 124 | /* Now queue of_dma controller structure in list */ |
Lars-Peter Clausen | de61608 | 2013-04-19 11:42:14 +0200 | [diff] [blame] | 125 | mutex_lock(&of_dma_lock); |
Jon Hunter | 9743a3b | 2012-10-11 14:43:01 -0500 | [diff] [blame] | 126 | list_add_tail(&ofdma->of_dma_controllers, &of_dma_list); |
Lars-Peter Clausen | de61608 | 2013-04-19 11:42:14 +0200 | [diff] [blame] | 127 | mutex_unlock(&of_dma_lock); |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 128 | |
| 129 | return 0; |
| 130 | } |
| 131 | EXPORT_SYMBOL_GPL(of_dma_controller_register); |
| 132 | |
| 133 | /** |
| 134 | * of_dma_controller_free - Remove a DMA controller from DT DMA helpers list |
| 135 | * @np: device node of DMA controller |
| 136 | * |
| 137 | * Memory allocated by of_dma_controller_register() is freed here. |
| 138 | */ |
Lars-Peter Clausen | de61608 | 2013-04-19 11:42:14 +0200 | [diff] [blame] | 139 | void of_dma_controller_free(struct device_node *np) |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 140 | { |
| 141 | struct of_dma *ofdma; |
| 142 | |
Lars-Peter Clausen | de61608 | 2013-04-19 11:42:14 +0200 | [diff] [blame] | 143 | mutex_lock(&of_dma_lock); |
Jon Hunter | 9743a3b | 2012-10-11 14:43:01 -0500 | [diff] [blame] | 144 | |
| 145 | list_for_each_entry(ofdma, &of_dma_list, of_dma_controllers) |
| 146 | if (ofdma->of_node == np) { |
Jon Hunter | 9743a3b | 2012-10-11 14:43:01 -0500 | [diff] [blame] | 147 | list_del(&ofdma->of_dma_controllers); |
Jon Hunter | 9743a3b | 2012-10-11 14:43:01 -0500 | [diff] [blame] | 148 | kfree(ofdma); |
Lars-Peter Clausen | de61608 | 2013-04-19 11:42:14 +0200 | [diff] [blame] | 149 | break; |
Jon Hunter | 9743a3b | 2012-10-11 14:43:01 -0500 | [diff] [blame] | 150 | } |
| 151 | |
Lars-Peter Clausen | de61608 | 2013-04-19 11:42:14 +0200 | [diff] [blame] | 152 | mutex_unlock(&of_dma_lock); |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 153 | } |
| 154 | EXPORT_SYMBOL_GPL(of_dma_controller_free); |
| 155 | |
| 156 | /** |
Peter Ujfalusi | 56f13c0 | 2015-04-09 12:35:47 +0300 | [diff] [blame^] | 157 | * of_dma_router_register - Register a DMA router to DT DMA helpers as a |
| 158 | * controller |
| 159 | * @np: device node of DMA router |
| 160 | * @of_dma_route_allocate: setup function for the router which need to |
| 161 | * modify the dma_spec for the DMA controller to |
| 162 | * use and to set up the requested route. |
| 163 | * @dma_router: pointer to dma_router structure to be used when |
| 164 | * the route need to be free up. |
| 165 | * |
| 166 | * Returns 0 on success or appropriate errno value on error. |
| 167 | * |
| 168 | * Allocated memory should be freed with appropriate of_dma_controller_free() |
| 169 | * call. |
| 170 | */ |
| 171 | int of_dma_router_register(struct device_node *np, |
| 172 | void *(*of_dma_route_allocate) |
| 173 | (struct of_phandle_args *, struct of_dma *), |
| 174 | struct dma_router *dma_router) |
| 175 | { |
| 176 | struct of_dma *ofdma; |
| 177 | |
| 178 | if (!np || !of_dma_route_allocate || !dma_router) { |
| 179 | pr_err("%s: not enough information provided\n", __func__); |
| 180 | return -EINVAL; |
| 181 | } |
| 182 | |
| 183 | ofdma = kzalloc(sizeof(*ofdma), GFP_KERNEL); |
| 184 | if (!ofdma) |
| 185 | return -ENOMEM; |
| 186 | |
| 187 | ofdma->of_node = np; |
| 188 | ofdma->of_dma_xlate = of_dma_router_xlate; |
| 189 | ofdma->of_dma_route_allocate = of_dma_route_allocate; |
| 190 | ofdma->dma_router = dma_router; |
| 191 | |
| 192 | /* Now queue of_dma controller structure in list */ |
| 193 | mutex_lock(&of_dma_lock); |
| 194 | list_add_tail(&ofdma->of_dma_controllers, &of_dma_list); |
| 195 | mutex_unlock(&of_dma_lock); |
| 196 | |
| 197 | return 0; |
| 198 | } |
| 199 | EXPORT_SYMBOL_GPL(of_dma_router_register); |
| 200 | |
| 201 | /** |
Jon Hunter | 5ca7c10 | 2012-09-25 13:59:31 -0500 | [diff] [blame] | 202 | * of_dma_match_channel - Check if a DMA specifier matches name |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 203 | * @np: device node to look for DMA channels |
Jon Hunter | 5ca7c10 | 2012-09-25 13:59:31 -0500 | [diff] [blame] | 204 | * @name: channel name to be matched |
| 205 | * @index: index of DMA specifier in list of DMA specifiers |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 206 | * @dma_spec: pointer to DMA specifier as found in the device tree |
| 207 | * |
Jon Hunter | 5ca7c10 | 2012-09-25 13:59:31 -0500 | [diff] [blame] | 208 | * Check if the DMA specifier pointed to by the index in a list of DMA |
| 209 | * specifiers, matches the name provided. Returns 0 if the name matches and |
| 210 | * a valid pointer to the DMA specifier is found. Otherwise returns -ENODEV. |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 211 | */ |
Markus Pargmann | bef29ec | 2013-02-24 16:36:09 +0100 | [diff] [blame] | 212 | static int of_dma_match_channel(struct device_node *np, const char *name, |
| 213 | int index, struct of_phandle_args *dma_spec) |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 214 | { |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 215 | const char *s; |
| 216 | |
Jon Hunter | 5ca7c10 | 2012-09-25 13:59:31 -0500 | [diff] [blame] | 217 | if (of_property_read_string_index(np, "dma-names", index, &s)) |
| 218 | return -ENODEV; |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 219 | |
Jon Hunter | 5ca7c10 | 2012-09-25 13:59:31 -0500 | [diff] [blame] | 220 | if (strcmp(name, s)) |
| 221 | return -ENODEV; |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 222 | |
Jon Hunter | 5ca7c10 | 2012-09-25 13:59:31 -0500 | [diff] [blame] | 223 | if (of_parse_phandle_with_args(np, "dmas", "#dma-cells", index, |
| 224 | dma_spec)) |
| 225 | return -ENODEV; |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 226 | |
Jon Hunter | 5ca7c10 | 2012-09-25 13:59:31 -0500 | [diff] [blame] | 227 | return 0; |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 228 | } |
| 229 | |
| 230 | /** |
| 231 | * of_dma_request_slave_channel - Get the DMA slave channel |
| 232 | * @np: device node to get DMA request from |
| 233 | * @name: name of desired channel |
| 234 | * |
Stephen Warren | 0ad7c00 | 2013-11-26 10:04:22 -0700 | [diff] [blame] | 235 | * Returns pointer to appropriate DMA channel on success or an error pointer. |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 236 | */ |
| 237 | struct dma_chan *of_dma_request_slave_channel(struct device_node *np, |
Markus Pargmann | bef29ec | 2013-02-24 16:36:09 +0100 | [diff] [blame] | 238 | const char *name) |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 239 | { |
| 240 | struct of_phandle_args dma_spec; |
| 241 | struct of_dma *ofdma; |
| 242 | struct dma_chan *chan; |
Jon Hunter | 5ca7c10 | 2012-09-25 13:59:31 -0500 | [diff] [blame] | 243 | int count, i; |
Stephen Warren | 0ad7c00 | 2013-11-26 10:04:22 -0700 | [diff] [blame] | 244 | int ret_no_channel = -ENODEV; |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 245 | |
| 246 | if (!np || !name) { |
| 247 | pr_err("%s: not enough information provided\n", __func__); |
Stephen Warren | 0ad7c00 | 2013-11-26 10:04:22 -0700 | [diff] [blame] | 248 | return ERR_PTR(-ENODEV); |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 249 | } |
| 250 | |
Wolfram Sang | c914570 | 2015-01-14 15:16:28 +0100 | [diff] [blame] | 251 | /* Silently fail if there is not even the "dmas" property */ |
| 252 | if (!of_find_property(np, "dmas", NULL)) |
| 253 | return ERR_PTR(-ENODEV); |
| 254 | |
Jon Hunter | 5ca7c10 | 2012-09-25 13:59:31 -0500 | [diff] [blame] | 255 | count = of_property_count_strings(np, "dma-names"); |
| 256 | if (count < 0) { |
Lothar Waßmann | 303fd71 | 2013-07-31 16:14:35 +0200 | [diff] [blame] | 257 | pr_err("%s: dma-names property of node '%s' missing or empty\n", |
| 258 | __func__, np->full_name); |
Stephen Warren | 0ad7c00 | 2013-11-26 10:04:22 -0700 | [diff] [blame] | 259 | return ERR_PTR(-ENODEV); |
Jon Hunter | 5ca7c10 | 2012-09-25 13:59:31 -0500 | [diff] [blame] | 260 | } |
| 261 | |
| 262 | for (i = 0; i < count; i++) { |
| 263 | if (of_dma_match_channel(np, name, i, &dma_spec)) |
| 264 | continue; |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 265 | |
Lars-Peter Clausen | de61608 | 2013-04-19 11:42:14 +0200 | [diff] [blame] | 266 | mutex_lock(&of_dma_lock); |
| 267 | ofdma = of_dma_find_controller(&dma_spec); |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 268 | |
Stephen Warren | 0ad7c00 | 2013-11-26 10:04:22 -0700 | [diff] [blame] | 269 | if (ofdma) { |
Lars-Peter Clausen | f22eb14 | 2013-04-19 11:42:13 +0200 | [diff] [blame] | 270 | chan = ofdma->of_dma_xlate(&dma_spec, ofdma); |
Stephen Warren | 0ad7c00 | 2013-11-26 10:04:22 -0700 | [diff] [blame] | 271 | } else { |
| 272 | ret_no_channel = -EPROBE_DEFER; |
Lars-Peter Clausen | f22eb14 | 2013-04-19 11:42:13 +0200 | [diff] [blame] | 273 | chan = NULL; |
Stephen Warren | 0ad7c00 | 2013-11-26 10:04:22 -0700 | [diff] [blame] | 274 | } |
Lars-Peter Clausen | de61608 | 2013-04-19 11:42:14 +0200 | [diff] [blame] | 275 | |
| 276 | mutex_unlock(&of_dma_lock); |
Jon Hunter | 9743a3b | 2012-10-11 14:43:01 -0500 | [diff] [blame] | 277 | |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 278 | of_node_put(dma_spec.np); |
| 279 | |
Jon Hunter | 5ca7c10 | 2012-09-25 13:59:31 -0500 | [diff] [blame] | 280 | if (chan) |
| 281 | return chan; |
| 282 | } |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 283 | |
Stephen Warren | 0ad7c00 | 2013-11-26 10:04:22 -0700 | [diff] [blame] | 284 | return ERR_PTR(ret_no_channel); |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 285 | } |
Kuninori Morimoto | 0aed112 | 2015-02-24 00:54:16 +0000 | [diff] [blame] | 286 | EXPORT_SYMBOL_GPL(of_dma_request_slave_channel); |
Jon Hunter | aa3da64 | 2012-09-14 17:41:56 -0500 | [diff] [blame] | 287 | |
| 288 | /** |
| 289 | * of_dma_simple_xlate - Simple DMA engine translation function |
| 290 | * @dma_spec: pointer to DMA specifier as found in the device tree |
| 291 | * @of_dma: pointer to DMA controller data |
| 292 | * |
| 293 | * A simple translation function for devices that use a 32-bit value for the |
| 294 | * filter_param when calling the DMA engine dma_request_channel() function. |
| 295 | * Note that this translation function requires that #dma-cells is equal to 1 |
| 296 | * and the argument of the dma specifier is the 32-bit filter_param. Returns |
| 297 | * pointer to appropriate dma channel on success or NULL on error. |
| 298 | */ |
| 299 | struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec, |
| 300 | struct of_dma *ofdma) |
| 301 | { |
| 302 | int count = dma_spec->args_count; |
| 303 | struct of_dma_filter_info *info = ofdma->of_dma_data; |
| 304 | |
| 305 | if (!info || !info->filter_fn) |
| 306 | return NULL; |
| 307 | |
| 308 | if (count != 1) |
| 309 | return NULL; |
| 310 | |
| 311 | return dma_request_channel(info->dma_cap, info->filter_fn, |
| 312 | &dma_spec->args[0]); |
| 313 | } |
| 314 | EXPORT_SYMBOL_GPL(of_dma_simple_xlate); |
Alexander Popov | 16369ef | 2014-06-25 14:52:59 +0400 | [diff] [blame] | 315 | |
| 316 | /** |
| 317 | * of_dma_xlate_by_chan_id - Translate dt property to DMA channel by channel id |
| 318 | * @dma_spec: pointer to DMA specifier as found in the device tree |
| 319 | * @of_dma: pointer to DMA controller data |
| 320 | * |
| 321 | * This function can be used as the of xlate callback for DMA driver which wants |
| 322 | * to match the channel based on the channel id. When using this xlate function |
| 323 | * the #dma-cells propety of the DMA controller dt node needs to be set to 1. |
| 324 | * The data parameter of of_dma_controller_register must be a pointer to the |
| 325 | * dma_device struct the function should match upon. |
| 326 | * |
| 327 | * Returns pointer to appropriate dma channel on success or NULL on error. |
| 328 | */ |
| 329 | struct dma_chan *of_dma_xlate_by_chan_id(struct of_phandle_args *dma_spec, |
| 330 | struct of_dma *ofdma) |
| 331 | { |
| 332 | struct dma_device *dev = ofdma->of_dma_data; |
| 333 | struct dma_chan *chan, *candidate = NULL; |
| 334 | |
| 335 | if (!dev || dma_spec->args_count != 1) |
| 336 | return NULL; |
| 337 | |
| 338 | list_for_each_entry(chan, &dev->channels, device_node) |
| 339 | if (chan->chan_id == dma_spec->args[0]) { |
| 340 | candidate = chan; |
| 341 | break; |
| 342 | } |
| 343 | |
| 344 | if (!candidate) |
| 345 | return NULL; |
| 346 | |
| 347 | return dma_get_slave_channel(candidate); |
| 348 | } |
| 349 | EXPORT_SYMBOL_GPL(of_dma_xlate_by_chan_id); |