1 // SPDX-License-Identifier: GPL-2.0-only
3  * ACPI helpers for DMA request / controller
5  * Based on of-dma.c
13 #include <linux/dma-mapping.h>
29  * acpi_dma_parse_resource_group - match device and parse resource group
32  * @adma:	struct acpi_dma of the given DMA controller
50 	if (grp->shared_info_length != sizeof(struct acpi_csrt_shared_info))  in acpi_dma_parse_resource_group()
51 		return -ENODEV;  in acpi_dma_parse_resource_group()
59 		if (resource_type(rentry->res) == IORESOURCE_MEM)  in acpi_dma_parse_resource_group()
60 			mem = rentry->res->start;  in acpi_dma_parse_resource_group()
61 		else if (resource_type(rentry->res) == IORESOURCE_IRQ)  in acpi_dma_parse_resource_group()
62 			irq = rentry->res->start;  in acpi_dma_parse_resource_group()
74 	if (si->mmio_base_low != lower_32_bits(mem) ||  in acpi_dma_parse_resource_group()
75 	    si->mmio_base_high != upper_32_bits(mem))  in acpi_dma_parse_resource_group()
83 	ret = acpi_register_gsi(NULL, si->gsi_interrupt, si->interrupt_mode, si->interrupt_polarity);  in acpi_dma_parse_resource_group()
91 	dev_dbg(&adev->dev, "matches with %.4s%04X (rev %u)\n",  in acpi_dma_parse_resource_group()
92 		(char *)&grp->vendor_id, grp->device_id, grp->revision);  in acpi_dma_parse_resource_group()
95 	if (si->base_request_line == 0 && si->num_handshake_signals == 0)  in acpi_dma_parse_resource_group()
99 	ret = dma_coerce_mask_and_coherent(&adev->dev,  in acpi_dma_parse_resource_group()
100 					   DMA_BIT_MASK(si->dma_address_width));  in acpi_dma_parse_resource_group()
104 	adma->base_request_line = si->base_request_line;  in acpi_dma_parse_resource_group()
105 	adma->end_request_line = si->base_request_line +  in acpi_dma_parse_resource_group()
106 				 si->num_handshake_signals - 1;  in acpi_dma_parse_resource_group()
108 	dev_dbg(&adev->dev, "request line base: 0x%04x end: 0x%04x\n",  in acpi_dma_parse_resource_group()
109 		adma->base_request_line, adma->end_request_line);  in acpi_dma_parse_resource_group()
115  * acpi_dma_parse_csrt - parse CSRT to extract additional DMA resources
117  * @adma:	struct acpi_dma of the given DMA controller
125  * controller to be used later.
138 			dev_warn(&adev->dev, "failed to get the CSRT table\n");  in acpi_dma_parse_csrt()
143 	end = (struct acpi_csrt_group *)((void *)csrt + csrt->header.length);  in acpi_dma_parse_csrt()
148 			dev_warn(&adev->dev,  in acpi_dma_parse_csrt()
153 		grp = (struct acpi_csrt_group *)((void *)grp + grp->length);  in acpi_dma_parse_csrt()
160  * acpi_dma_controller_register - Register a DMA controller to ACPI DMA helpers
161  * @dev:		struct device of DMA controller
164  * @data:		pointer to controller specific data to be used by
176 		void *data)  in acpi_dma_controller_register()  argument
182 		return -EINVAL;  in acpi_dma_controller_register()
187 		return -EINVAL;  in acpi_dma_controller_register()
191 		return -ENOMEM;  in acpi_dma_controller_register()
193 	adma->dev = dev;  in acpi_dma_controller_register()
194 	adma->acpi_dma_xlate = acpi_dma_xlate;  in acpi_dma_controller_register()
195 	adma->data = data;  in acpi_dma_controller_register()
199 	/* Now queue acpi_dma controller structure in list */  in acpi_dma_controller_register()
201 	list_add_tail(&adma->dma_controllers, &acpi_dma_list);  in acpi_dma_controller_register()
209  * acpi_dma_controller_free - Remove a DMA controller from ACPI DMA helpers list
210  * @dev:	struct device of DMA controller
222 		return -EINVAL;  in acpi_dma_controller_free()
227 		if (adma->dev == dev) {  in acpi_dma_controller_free()
228 			list_del(&adma->dma_controllers);  in acpi_dma_controller_free()
235 	return -ENODEV;  in acpi_dma_controller_free()
245  * devm_acpi_dma_controller_register - resource managed acpi_dma_controller_register()
246  * @dev:		device that is registering this DMA controller
248  * @data:		pointer to controller specific data
250  * Managed acpi_dma_controller_register(). DMA controller registered by this
260 		void *data)  in devm_acpi_dma_controller_register()  argument
267 		return -ENOMEM;  in devm_acpi_dma_controller_register()
269 	ret = acpi_dma_controller_register(dev, acpi_dma_xlate, data);  in devm_acpi_dma_controller_register()
280  * devm_acpi_dma_controller_free - resource managed acpi_dma_controller_free()
281  * @dev:	device that is unregistering as DMA controller
283  * Unregister a DMA controller registered with
295  * acpi_dma_update_dma_spec - prepare dma specifier to pass to translation function
296  * @adma:	struct acpi_dma of DMA controller
299  * Accordingly to ACPI 5.0 Specification Table 6-170 "Fixed DMA Resource
301  *	DMA Request Line bits is a platform-relative number uniquely
302  *	identifying the request line assigned. Request line-to-Controller
303  *	mapping is done in a controller-specific OS driver.
304  * That's why we can safely adjust slave_id when the appropriate controller is
308  * 0, if no information is available, -1 on mismatch, and 1 otherwise.
313 	/* Set link to the DMA controller device */  in acpi_dma_update_dma_spec()
314 	dma_spec->dev = adma->dev;  in acpi_dma_update_dma_spec()
317 	if (adma->base_request_line == 0 && adma->end_request_line == 0)  in acpi_dma_update_dma_spec()
321 	if (dma_spec->slave_id < adma->base_request_line ||  in acpi_dma_update_dma_spec()
322 	    dma_spec->slave_id > adma->end_request_line)  in acpi_dma_update_dma_spec()
323 		return -1;  in acpi_dma_update_dma_spec()
329 	dma_spec->slave_id -= adma->base_request_line;  in acpi_dma_update_dma_spec()
341  * acpi_dma_parse_fixed_dma - Parse FixedDMA ACPI resources to a DMA specifier
343  * @data:	pointer to a helper struct acpi_dma_parser_data
345 static int acpi_dma_parse_fixed_dma(struct acpi_resource *res, void *data)  in acpi_dma_parse_fixed_dma()  argument
347 	struct acpi_dma_parser_data *pdata = data;  in acpi_dma_parse_fixed_dma()
349 	if (res->type == ACPI_RESOURCE_TYPE_FIXED_DMA) {  in acpi_dma_parse_fixed_dma()
350 		struct acpi_resource_fixed_dma *dma = &res->data.fixed_dma;  in acpi_dma_parse_fixed_dma()
352 		if (pdata->n++ == pdata->index) {  in acpi_dma_parse_fixed_dma()
353 			pdata->dma_spec.chan_id = dma->channels;  in acpi_dma_parse_fixed_dma()
354 			pdata->dma_spec.slave_id = dma->request_lines;  in acpi_dma_parse_fixed_dma()
363  * acpi_dma_request_slave_chan_by_index - Get the DMA slave channel
386 	dma_spec->chan_id = -1;  in acpi_dma_request_slave_chan_by_index()
387 	dma_spec->slave_id = -1;  in acpi_dma_request_slave_chan_by_index()
396 	if (dma_spec->slave_id < 0 || dma_spec->chan_id < 0)  in acpi_dma_request_slave_chan_by_index()
397 		return ERR_PTR(-ENODEV);  in acpi_dma_request_slave_chan_by_index()
409 		chan = adma->acpi_dma_xlate(dma_spec, adma);  in acpi_dma_request_slave_chan_by_index()
411 		 * Try to get a channel only from the DMA controller that  in acpi_dma_request_slave_chan_by_index()
420 	return chan ? chan : ERR_PTR(-EPROBE_DEFER);  in acpi_dma_request_slave_chan_by_index()
425  * acpi_dma_request_slave_chan_by_name - Get the DMA slave channel
433  * If the device has "dma-names" property the FixedDMA descriptor indices
445 	index = device_property_match_string(dev, "dma-names", name);  in acpi_dma_request_slave_chan_by_name()
452 			return ERR_PTR(-ENODEV);  in acpi_dma_request_slave_chan_by_name()
461  * acpi_dma_simple_xlate - Simple ACPI DMA engine translation helper
463  * @adma: pointer to ACPI DMA controller data
466  * dma_spec to the DMA controller driver provided filter function.
474 	struct acpi_dma_filter_info *info = adma->data;  in acpi_dma_simple_xlate()
476 	if (!info || !info->filter_fn)  in acpi_dma_simple_xlate()
479 	return dma_request_channel(info->dma_cap, info->filter_fn, dma_spec);  in acpi_dma_simple_xlate()