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
47 	resource_size_t mem = 0, irq = 0;  in acpi_dma_parse_resource_group()  local
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()
68 	if (mem == 0 && irq == 0)  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()
76 	    si->gsi_interrupt != irq)  in acpi_dma_parse_resource_group()
79 	dev_dbg(&adev->dev, "matches with %.4s%04X (rev %u)\n",  in acpi_dma_parse_resource_group()
80 		(char *)&grp->vendor_id, grp->device_id, grp->revision);  in acpi_dma_parse_resource_group()
83 	if (si->base_request_line == 0 && si->num_handshake_signals == 0)  in acpi_dma_parse_resource_group()
86 	/* Set up DMA mask based on value from CSRT */  in acpi_dma_parse_resource_group()
87 	ret = dma_coerce_mask_and_coherent(&adev->dev,  in acpi_dma_parse_resource_group()
88 					   DMA_BIT_MASK(si->dma_address_width));  in acpi_dma_parse_resource_group()
92 	adma->base_request_line = si->base_request_line;  in acpi_dma_parse_resource_group()
93 	adma->end_request_line = si->base_request_line +  in acpi_dma_parse_resource_group()
94 				 si->num_handshake_signals - 1;  in acpi_dma_parse_resource_group()
96 	dev_dbg(&adev->dev, "request line base: 0x%04x end: 0x%04x\n",  in acpi_dma_parse_resource_group()
97 		adma->base_request_line, adma->end_request_line);  in acpi_dma_parse_resource_group()
103  * acpi_dma_parse_csrt - parse CSRT to exctract additional DMA resources
105  * @adma:	struct acpi_dma of the given DMA controller
109  * the system DSDT table. In particular DMA controllers might be described
112  * We are using this table to get the request line range of the specific DMA
126 			dev_warn(&adev->dev, "failed to get the CSRT table\n");  in acpi_dma_parse_csrt()
131 	end = (struct acpi_csrt_group *)((void *)csrt + csrt->header.length);  in acpi_dma_parse_csrt()
136 			dev_warn(&adev->dev,  in acpi_dma_parse_csrt()
141 		grp = (struct acpi_csrt_group *)((void *)grp + grp->length);  in acpi_dma_parse_csrt()
148  * acpi_dma_controller_register - Register a DMA controller to ACPI DMA helpers
149  * @dev:		struct device of DMA controller
150  * @acpi_dma_xlate:	translation function which converts a dma specifier
170 		return -EINVAL;  in acpi_dma_controller_register()
175 		return -EINVAL;  in acpi_dma_controller_register()
179 		return -ENOMEM;  in acpi_dma_controller_register()
181 	adma->dev = dev;  in acpi_dma_controller_register()
182 	adma->acpi_dma_xlate = acpi_dma_xlate;  in acpi_dma_controller_register()
183 	adma->data = data;  in acpi_dma_controller_register()
189 	list_add_tail(&adma->dma_controllers, &acpi_dma_list);  in acpi_dma_controller_register()
197  * acpi_dma_controller_free - Remove a DMA controller from ACPI DMA helpers list
198  * @dev:	struct device of DMA controller
210 		return -EINVAL;  in acpi_dma_controller_free()
215 		if (adma->dev == dev) {  in acpi_dma_controller_free()
216 			list_del(&adma->dma_controllers);  in acpi_dma_controller_free()
223 	return -ENODEV;  in acpi_dma_controller_free()
233  * devm_acpi_dma_controller_register - resource managed acpi_dma_controller_register()
234  * @dev:		device that is registering this DMA controller
238  * Managed acpi_dma_controller_register(). DMA controller registered by this
255 		return -ENOMEM;  in devm_acpi_dma_controller_register()
268  * devm_acpi_dma_controller_free - resource managed acpi_dma_controller_free()
269  * @dev:	device that is unregistering as DMA controller
271  * Unregister a DMA controller registered with
283  * acpi_dma_update_dma_spec - prepare dma specifier to pass to translation function
284  * @adma:	struct acpi_dma of DMA controller
285  * @dma_spec:	dma specifier to update
287  * Accordingly to ACPI 5.0 Specification Table 6-170 "Fixed DMA Resource
289  *	DMA Request Line bits is a platform-relative number uniquely
290  *	identifying the request line assigned. Request line-to-Controller
291  *	mapping is done in a controller-specific OS driver.
296  * 0, if no information is avaiable, -1 on mismatch, and 1 otherwise.
301 	/* Set link to the DMA controller device */  in acpi_dma_update_dma_spec()
302 	dma_spec->dev = adma->dev;  in acpi_dma_update_dma_spec()
305 	if (adma->base_request_line == 0 && adma->end_request_line == 0)  in acpi_dma_update_dma_spec()
309 	if (dma_spec->slave_id < adma->base_request_line ||  in acpi_dma_update_dma_spec()
310 	    dma_spec->slave_id > adma->end_request_line)  in acpi_dma_update_dma_spec()
311 		return -1;  in acpi_dma_update_dma_spec()
317 	dma_spec->slave_id -= adma->base_request_line;  in acpi_dma_update_dma_spec()
329  * acpi_dma_parse_fixed_dma - Parse FixedDMA ACPI resources to a DMA specifier
337 	if (res->type == ACPI_RESOURCE_TYPE_FIXED_DMA) {  in acpi_dma_parse_fixed_dma()
338 		struct acpi_resource_fixed_dma *dma = &res->data.fixed_dma;  in acpi_dma_parse_fixed_dma()  local
340 		if (pdata->n++ == pdata->index) {  in acpi_dma_parse_fixed_dma()
341 			pdata->dma_spec.chan_id = dma->channels;  in acpi_dma_parse_fixed_dma()
342 			pdata->dma_spec.slave_id = dma->request_lines;  in acpi_dma_parse_fixed_dma()
351  * acpi_dma_request_slave_chan_by_index - Get the DMA slave channel
352  * @dev:	struct device to get DMA request from
356  * Pointer to appropriate dma channel on success or an error pointer.
374 	dma_spec->chan_id = -1;  in acpi_dma_request_slave_chan_by_index()
375 	dma_spec->slave_id = -1;  in acpi_dma_request_slave_chan_by_index()
384 	if (dma_spec->slave_id < 0 || dma_spec->chan_id < 0)  in acpi_dma_request_slave_chan_by_index()
385 		return ERR_PTR(-ENODEV);  in acpi_dma_request_slave_chan_by_index()
397 		chan = adma->acpi_dma_xlate(dma_spec, adma);  in acpi_dma_request_slave_chan_by_index()
399 		 * Try to get a channel only from the DMA controller that  in acpi_dma_request_slave_chan_by_index()
408 	return chan ? chan : ERR_PTR(-EPROBE_DEFER);  in acpi_dma_request_slave_chan_by_index()
413  * acpi_dma_request_slave_chan_by_name - Get the DMA slave channel
414  * @dev:	struct device to get DMA request from
421  * If the device has "dma-names" property the FixedDMA descriptor indices
426  * Pointer to appropriate dma channel on success or an error pointer.
433 	index = device_property_match_string(dev, "dma-names", name);  in acpi_dma_request_slave_chan_by_name()
440 			return ERR_PTR(-ENODEV);  in acpi_dma_request_slave_chan_by_name()
443 	dev_dbg(dev, "Looking for DMA channel \"%s\" at index %d...\n", name, index);  in acpi_dma_request_slave_chan_by_name()
449  * acpi_dma_simple_xlate - Simple ACPI DMA engine translation helper
450  * @dma_spec: pointer to ACPI DMA specifier
451  * @adma: pointer to ACPI DMA controller data
454  * dma_spec to the DMA controller driver provided filter function.
462 	struct acpi_dma_filter_info *info = adma->data;  in acpi_dma_simple_xlate()
464 	if (!info || !info->filter_fn)  in acpi_dma_simple_xlate()
467 	return dma_request_channel(info->dma_cap, info->filter_fn, dma_spec);  in acpi_dma_simple_xlate()