2  * Device tree helpers for DMA request / controller
6  * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
25  * of_dma_find_controller - Get a DMA controller in DT DMA helpers list
26  * @dma_spec:	pointer to DMA specifier as found in the device tree
28  * Finds a DMA controller with matching device node and number for dma cells
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
38 		if (ofdma->of_node == dma_spec->np)  in of_dma_find_controller()
41 	pr_debug("%s: can't find DMA controller %pOF\n", __func__,  in of_dma_find_controller()
42 		 dma_spec->np);  in of_dma_find_controller()
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)
54  * to request channel from the real DMA controller.
64 	/* translate the request for the real DMA controller */  in of_dma_router_xlate()
66 	route_data = ofdma->of_dma_route_allocate(&dma_spec_target, ofdma);  in of_dma_router_xlate()
74 	chan = ofdma_target->of_dma_xlate(&dma_spec_target, ofdma_target);  in of_dma_router_xlate()
76 		ofdma->dma_router->route_free(ofdma->dma_router->dev,  in of_dma_router_xlate()
79 		chan->router = ofdma->dma_router;  in of_dma_router_xlate()
80 		chan->route_data = route_data;  in of_dma_router_xlate()
84 	 * Need to put the node back since the ofdma->of_dma_route_allocate  in of_dma_router_xlate()
92  * of_dma_controller_register - Register a DMA controller to DT DMA helpers
93  * @np:			device node of DMA controller
96  * @data		pointer to controller specific data to be used by
113 		return -EINVAL;  in of_dma_controller_register()
118 		return -ENOMEM;  in of_dma_controller_register()
120 	ofdma->of_node = np;  in of_dma_controller_register()
121 	ofdma->of_dma_xlate = of_dma_xlate;  in of_dma_controller_register()
122 	ofdma->of_dma_data = data;  in of_dma_controller_register()
124 	/* Now queue of_dma controller structure in list */  in of_dma_controller_register()
126 	list_add_tail(&ofdma->of_dma_controllers, &of_dma_list);  in of_dma_controller_register()
134  * of_dma_controller_free - Remove a DMA controller from DT DMA helpers list
135  * @np:		device node of DMA controller
146 		if (ofdma->of_node == np) {  in of_dma_controller_free()
147 			list_del(&ofdma->of_dma_controllers);  in of_dma_controller_free()
157  * of_dma_router_register - Register a DMA router to DT DMA helpers as a
158  *			    controller
159  * @np:				device node of DMA router
161  *				modify the dma_spec for the DMA controller to
180 		return -EINVAL;  in of_dma_router_register()
185 		return -ENOMEM;  in of_dma_router_register()
187 	ofdma->of_node = np;  in of_dma_router_register()
188 	ofdma->of_dma_xlate = of_dma_router_xlate;  in of_dma_router_register()
189 	ofdma->of_dma_route_allocate = of_dma_route_allocate;  in of_dma_router_register()
190 	ofdma->dma_router = dma_router;  in of_dma_router_register()
192 	/* Now queue of_dma controller structure in list */  in of_dma_router_register()
194 	list_add_tail(&ofdma->of_dma_controllers, &of_dma_list);  in of_dma_router_register()
202  * of_dma_match_channel - Check if a DMA specifier matches name
203  * @np:		device node to look for DMA channels
205  * @index:	index of DMA specifier in list of DMA specifiers
206  * @dma_spec:	pointer to DMA specifier as found in the device tree
208  * Check if the DMA specifier pointed to by the index in a list of DMA
210  * a valid pointer to the DMA specifier is found. Otherwise returns -ENODEV.
217 	if (of_property_read_string_index(np, "dma-names", index, &s))  in of_dma_match_channel()
218 		return -ENODEV;  in of_dma_match_channel()
221 		return -ENODEV;  in of_dma_match_channel()
223 	if (of_parse_phandle_with_args(np, "dmas", "#dma-cells", index,  in of_dma_match_channel()
225 		return -ENODEV;  in of_dma_match_channel()
231  * of_dma_request_slave_channel - Get the DMA slave channel
232  * @np:		device node to get DMA request from
235  * Returns pointer to appropriate DMA channel on success or an error pointer.
244 	int			ret_no_channel = -ENODEV;  in of_dma_request_slave_channel()
249 		return ERR_PTR(-ENODEV);  in of_dma_request_slave_channel()
254 		return ERR_PTR(-ENODEV);  in of_dma_request_slave_channel()
256 	count = of_property_count_strings(np, "dma-names");  in of_dma_request_slave_channel()
258 		pr_err("%s: dma-names property of node '%pOF' missing or empty\n",  in of_dma_request_slave_channel()
260 		return ERR_PTR(-ENODEV);  in of_dma_request_slave_channel()
278 			chan = ofdma->of_dma_xlate(&dma_spec, ofdma);  in of_dma_request_slave_channel()
280 			ret_no_channel = -EPROBE_DEFER;  in of_dma_request_slave_channel()
297  * of_dma_simple_xlate - Simple DMA engine translation function
298  * @dma_spec:	pointer to DMA specifier as found in the device tree
299  * @of_dma:	pointer to DMA controller data
301  * A simple translation function for devices that use a 32-bit value for the
302  * filter_param when calling the DMA engine dma_request_channel() function.
303  * Note that this translation function requires that #dma-cells is equal to 1
304  * and the argument of the dma specifier is the 32-bit filter_param. Returns
305  * pointer to appropriate dma channel on success or NULL on error.
310 	int count = dma_spec->args_count;  in of_dma_simple_xlate()
311 	struct of_dma_filter_info *info = ofdma->of_dma_data;  in of_dma_simple_xlate()
313 	if (!info || !info->filter_fn)  in of_dma_simple_xlate()
319 	return dma_request_channel(info->dma_cap, info->filter_fn,  in of_dma_simple_xlate()
320 			&dma_spec->args[0]);  in of_dma_simple_xlate()
325  * of_dma_xlate_by_chan_id - Translate dt property to DMA channel by channel id
326  * @dma_spec:	pointer to DMA specifier as found in the device tree
327  * @of_dma:	pointer to DMA controller data
329  * This function can be used as the of xlate callback for DMA driver which wants
331  * the #dma-cells propety of the DMA controller dt node needs to be set to 1.
335  * Returns pointer to appropriate dma channel on success or NULL on error.
340 	struct dma_device *dev = ofdma->of_dma_data;  in of_dma_xlate_by_chan_id()
343 	if (!dev || dma_spec->args_count != 1)  in of_dma_xlate_by_chan_id()
346 	list_for_each_entry(chan, &dev->channels, device_node)  in of_dma_xlate_by_chan_id()
347 		if (chan->chan_id == dma_spec->args[0]) {  in of_dma_xlate_by_chan_id()