1 // SPDX-License-Identifier: GPL-2.0-only
3  * ACPI helpers for DMA request / controller
5  * Based on of-dma.c
12 #include <linux/acpi.h>
15 #include <linux/dma-mapping.h>
32  * acpi_dma_parse_resource_group - match device and parse resource group
34  * @adev:	ACPI device to match with
53 	if (grp->shared_info_length != sizeof(struct acpi_csrt_shared_info))  in acpi_dma_parse_resource_group()
54 		return -ENODEV;  in acpi_dma_parse_resource_group()
62 		if (resource_type(rentry->res) == IORESOURCE_MEM)  in acpi_dma_parse_resource_group()
63 			mem = rentry->res->start;  in acpi_dma_parse_resource_group()
64 		else if (resource_type(rentry->res) == IORESOURCE_IRQ)  in acpi_dma_parse_resource_group()
65 			irq = rentry->res->start;  in acpi_dma_parse_resource_group()
77 	if (si->mmio_base_low != lower_32_bits(mem) ||  in acpi_dma_parse_resource_group()
78 	    si->mmio_base_high != upper_32_bits(mem))  in acpi_dma_parse_resource_group()
86 	ret = acpi_register_gsi(NULL, si->gsi_interrupt, si->interrupt_mode, si->interrupt_polarity);  in acpi_dma_parse_resource_group()
94 	dev_dbg(&adev->dev, "matches with %.4s%04X (rev %u)\n",  in acpi_dma_parse_resource_group()
95 		(char *)&grp->vendor_id, grp->device_id, grp->revision);  in acpi_dma_parse_resource_group()
98 	if (si->base_request_line == 0 && si->num_handshake_signals == 0)  in acpi_dma_parse_resource_group()
101 	/* Set up DMA mask based on value from CSRT */  in acpi_dma_parse_resource_group()
102 	ret = dma_coerce_mask_and_coherent(&adev->dev,  in acpi_dma_parse_resource_group()
103 					   DMA_BIT_MASK(si->dma_address_width));  in acpi_dma_parse_resource_group()
107 	adma->base_request_line = si->base_request_line;  in acpi_dma_parse_resource_group()
108 	adma->end_request_line = si->base_request_line +  in acpi_dma_parse_resource_group()
109 				 si->num_handshake_signals - 1;  in acpi_dma_parse_resource_group()
111 	dev_dbg(&adev->dev, "request line base: 0x%04x end: 0x%04x\n",  in acpi_dma_parse_resource_group()
112 		adma->base_request_line, adma->end_request_line);  in acpi_dma_parse_resource_group()
118  * acpi_dma_parse_csrt - parse CSRT to extract additional DMA resources
119  * @adev:	ACPI device to match with
122  * CSRT or Core System Resources Table is a proprietary ACPI table
141 			dev_warn(&adev->dev, "failed to get the CSRT table\n");  in acpi_dma_parse_csrt()
146 	end = (struct acpi_csrt_group *)((void *)csrt + csrt->header.length);  in acpi_dma_parse_csrt()
151 			dev_warn(&adev->dev,  in acpi_dma_parse_csrt()
156 		grp = (struct acpi_csrt_group *)((void *)grp + grp->length);  in acpi_dma_parse_csrt()
163  * acpi_dma_controller_register - Register a DMA controller to ACPI DMA helpers
185 		return -EINVAL;  in acpi_dma_controller_register()
187 	/* Check if the device was enumerated by ACPI */  in acpi_dma_controller_register()
190 		return -EINVAL;  in acpi_dma_controller_register()
194 		return -ENOMEM;  in acpi_dma_controller_register()
196 	adma->dev = dev;  in acpi_dma_controller_register()
197 	adma->acpi_dma_xlate = acpi_dma_xlate;  in acpi_dma_controller_register()
198 	adma->data = data;  in acpi_dma_controller_register()
204 	list_add_tail(&adma->dma_controllers, &acpi_dma_list);  in acpi_dma_controller_register()
212  * acpi_dma_controller_free - Remove a DMA controller from ACPI DMA helpers list
225 		return -EINVAL;  in acpi_dma_controller_free()
230 		if (adma->dev == dev) {  in acpi_dma_controller_free()
231 			list_del(&adma->dma_controllers);  in acpi_dma_controller_free()
238 	return -ENODEV;  in acpi_dma_controller_free()
248  * devm_acpi_dma_controller_register - resource managed acpi_dma_controller_register()
276  * acpi_dma_update_dma_spec - prepare dma specifier to pass to translation function
280  * Accordingly to ACPI 5.0 Specification Table 6-170 "Fixed DMA Resource
282  *	DMA Request Line bits is a platform-relative number uniquely
283  *	identifying the request line assigned. Request line-to-Controller
284  *	mapping is done in a controller-specific OS driver.
289  * 0, if no information is available, -1 on mismatch, and 1 otherwise.
295 	dma_spec->dev = adma->dev;  in acpi_dma_update_dma_spec()
298 	if (adma->base_request_line == 0 && adma->end_request_line == 0)  in acpi_dma_update_dma_spec()
302 	if (dma_spec->slave_id < adma->base_request_line ||  in acpi_dma_update_dma_spec()
303 	    dma_spec->slave_id > adma->end_request_line)  in acpi_dma_update_dma_spec()
304 		return -1;  in acpi_dma_update_dma_spec()
310 	dma_spec->slave_id -= adma->base_request_line;  in acpi_dma_update_dma_spec()
322  * acpi_dma_parse_fixed_dma - Parse FixedDMA ACPI resources to a DMA specifier
330 	if (res->type == ACPI_RESOURCE_TYPE_FIXED_DMA) {  in acpi_dma_parse_fixed_dma()
331 		struct acpi_resource_fixed_dma *dma = &res->data.fixed_dma;  in acpi_dma_parse_fixed_dma()
333 		if (pdata->n++ == pdata->index) {  in acpi_dma_parse_fixed_dma()
334 			pdata->dma_spec.chan_id = dma->channels;  in acpi_dma_parse_fixed_dma()
335 			pdata->dma_spec.slave_id = dma->request_lines;  in acpi_dma_parse_fixed_dma()
339 	/* Tell the ACPI core to skip this resource */  in acpi_dma_parse_fixed_dma()
344  * acpi_dma_request_slave_chan_by_index - Get the DMA slave channel
367 	dma_spec->chan_id = -1;  in acpi_dma_request_slave_chan_by_index()
368 	dma_spec->slave_id = -1;  in acpi_dma_request_slave_chan_by_index()
377 	if (dma_spec->slave_id < 0 || dma_spec->chan_id < 0)  in acpi_dma_request_slave_chan_by_index()
378 		return ERR_PTR(-ENODEV);  in acpi_dma_request_slave_chan_by_index()
390 		chan = adma->acpi_dma_xlate(dma_spec, adma);  in acpi_dma_request_slave_chan_by_index()
401 	return chan ? chan : ERR_PTR(-EPROBE_DEFER);  in acpi_dma_request_slave_chan_by_index()
406  * acpi_dma_request_slave_chan_by_name - Get the DMA slave channel
410  * In order to support both Device Tree and ACPI in a single driver we
411  * translate the names "tx" and "rx" here based on the most common case where
414  * If the device has "dma-names" property the FixedDMA descriptor indices
415  * are retrieved based on those. Otherwise the function falls back using
426 	index = device_property_match_string(dev, "dma-names", name);  in acpi_dma_request_slave_chan_by_name()
433 			return ERR_PTR(-ENODEV);  in acpi_dma_request_slave_chan_by_name()
442  * acpi_dma_simple_xlate - Simple ACPI DMA engine translation helper
443  * @dma_spec: pointer to ACPI DMA specifier
444  * @adma: pointer to ACPI DMA controller data
446  * A simple translation function for ACPI based devices. Passes &struct
455 	struct acpi_dma_filter_info *info = adma->data;  in acpi_dma_simple_xlate()
457 	if (!info || !info->filter_fn)  in acpi_dma_simple_xlate()
460 	return dma_request_channel(info->dma_cap, info->filter_fn, dma_spec);  in acpi_dma_simple_xlate()