1 /*
2  * linux/drivers/misc/xillybus_pcie.c
3  *
4  * Copyright 2011 Xillybus Ltd, http://xillybus.com
5  *
6  * Driver for the Xillybus FPGA/host framework using PCI Express.
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the smems of the GNU General Public License as published by
10  * the Free Software Foundation; version 2 of the License.
11  */
12 
13 #include <linux/module.h>
14 #include <linux/pci.h>
15 #include <linux/pci-aspm.h>
16 #include <linux/slab.h>
17 #include "xillybus.h"
18 
19 MODULE_DESCRIPTION("Xillybus driver for PCIe");
20 MODULE_AUTHOR("Eli Billauer, Xillybus Ltd.");
21 MODULE_VERSION("1.06");
22 MODULE_ALIAS("xillybus_pcie");
23 MODULE_LICENSE("GPL v2");
24 
25 #define PCI_DEVICE_ID_XILLYBUS		0xebeb
26 
27 #define PCI_VENDOR_ID_ALTERA		0x1172
28 #define PCI_VENDOR_ID_ACTEL		0x11aa
29 #define PCI_VENDOR_ID_LATTICE		0x1204
30 
31 static const char xillyname[] = "xillybus_pcie";
32 
33 static const struct pci_device_id xillyids[] = {
34 	{PCI_DEVICE(PCI_VENDOR_ID_XILINX, PCI_DEVICE_ID_XILLYBUS)},
35 	{PCI_DEVICE(PCI_VENDOR_ID_ALTERA, PCI_DEVICE_ID_XILLYBUS)},
36 	{PCI_DEVICE(PCI_VENDOR_ID_ACTEL, PCI_DEVICE_ID_XILLYBUS)},
37 	{PCI_DEVICE(PCI_VENDOR_ID_LATTICE, PCI_DEVICE_ID_XILLYBUS)},
38 	{ /* End: all zeroes */ }
39 };
40 
41 static int xilly_pci_direction(int direction)
42 {
43 	switch (direction) {
44 	case DMA_TO_DEVICE:
45 		return PCI_DMA_TODEVICE;
46 	case DMA_FROM_DEVICE:
47 		return PCI_DMA_FROMDEVICE;
48 	default:
49 		return PCI_DMA_BIDIRECTIONAL;
50 	}
51 }
52 
53 static void xilly_dma_sync_single_for_cpu_pci(struct xilly_endpoint *ep,
54 					      dma_addr_t dma_handle,
55 					      size_t size,
56 					      int direction)
57 {
58 	pci_dma_sync_single_for_cpu(ep->pdev,
59 				    dma_handle,
60 				    size,
61 				    xilly_pci_direction(direction));
62 }
63 
64 static void xilly_dma_sync_single_for_device_pci(struct xilly_endpoint *ep,
65 						 dma_addr_t dma_handle,
66 						 size_t size,
67 						 int direction)
68 {
69 	pci_dma_sync_single_for_device(ep->pdev,
70 				       dma_handle,
71 				       size,
72 				       xilly_pci_direction(direction));
73 }
74 
75 static void xilly_pci_unmap(void *ptr)
76 {
77 	struct xilly_mapping *data = ptr;
78 
79 	pci_unmap_single(data->device, data->dma_addr,
80 			 data->size, data->direction);
81 
82 	kfree(ptr);
83 }
84 
85 /*
86  * Map either through the PCI DMA mapper or the non_PCI one. Behind the
87  * scenes exactly the same functions are called with the same parameters,
88  * but that can change.
89  */
90 
91 static int xilly_map_single_pci(struct xilly_endpoint *ep,
92 				void *ptr,
93 				size_t size,
94 				int direction,
95 				dma_addr_t *ret_dma_handle
96 	)
97 {
98 	int pci_direction;
99 	dma_addr_t addr;
100 	struct xilly_mapping *this;
101 	int rc;
102 
103 	this = kzalloc(sizeof(*this), GFP_KERNEL);
104 	if (!this)
105 		return -ENOMEM;
106 
107 	pci_direction = xilly_pci_direction(direction);
108 
109 	addr = pci_map_single(ep->pdev, ptr, size, pci_direction);
110 
111 	if (pci_dma_mapping_error(ep->pdev, addr)) {
112 		kfree(this);
113 		return -ENODEV;
114 	}
115 
116 	this->device = ep->pdev;
117 	this->dma_addr = addr;
118 	this->size = size;
119 	this->direction = pci_direction;
120 
121 	*ret_dma_handle = addr;
122 
123 	rc = devm_add_action(ep->dev, xilly_pci_unmap, this);
124 	if (rc) {
125 		pci_unmap_single(ep->pdev, addr, size, pci_direction);
126 		kfree(this);
127 		return rc;
128 	}
129 
130 	return 0;
131 }
132 
133 static struct xilly_endpoint_hardware pci_hw = {
134 	.owner = THIS_MODULE,
135 	.hw_sync_sgl_for_cpu = xilly_dma_sync_single_for_cpu_pci,
136 	.hw_sync_sgl_for_device = xilly_dma_sync_single_for_device_pci,
137 	.map_single = xilly_map_single_pci,
138 };
139 
140 static int xilly_probe(struct pci_dev *pdev,
141 		       const struct pci_device_id *ent)
142 {
143 	struct xilly_endpoint *endpoint;
144 	int rc;
145 
146 	endpoint = xillybus_init_endpoint(pdev, &pdev->dev, &pci_hw);
147 
148 	if (!endpoint)
149 		return -ENOMEM;
150 
151 	pci_set_drvdata(pdev, endpoint);
152 
153 	rc = pcim_enable_device(pdev);
154 	if (rc) {
155 		dev_err(endpoint->dev,
156 			"pcim_enable_device() failed. Aborting.\n");
157 		return rc;
158 	}
159 
160 	/* L0s has caused packet drops. No power saving, thank you. */
161 
162 	pci_disable_link_state(pdev, PCIE_LINK_STATE_L0S);
163 
164 	if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM)) {
165 		dev_err(endpoint->dev,
166 			"Incorrect BAR configuration. Aborting.\n");
167 		return -ENODEV;
168 	}
169 
170 	rc = pcim_iomap_regions(pdev, 0x01, xillyname);
171 	if (rc) {
172 		dev_err(endpoint->dev,
173 			"pcim_iomap_regions() failed. Aborting.\n");
174 		return rc;
175 	}
176 
177 	endpoint->registers = pcim_iomap_table(pdev)[0];
178 
179 	pci_set_master(pdev);
180 
181 	/* Set up a single MSI interrupt */
182 	if (pci_enable_msi(pdev)) {
183 		dev_err(endpoint->dev,
184 			"Failed to enable MSI interrupts. Aborting.\n");
185 		return -ENODEV;
186 	}
187 	rc = devm_request_irq(&pdev->dev, pdev->irq, xillybus_isr, 0,
188 			      xillyname, endpoint);
189 	if (rc) {
190 		dev_err(endpoint->dev,
191 			"Failed to register MSI handler. Aborting.\n");
192 		return -ENODEV;
193 	}
194 
195 	/*
196 	 * In theory, an attempt to set the DMA mask to 64 and dma_using_dac=1
197 	 * is the right thing. But some unclever PCIe drivers report it's OK
198 	 * when the hardware drops those 64-bit PCIe packets. So trust
199 	 * nobody and use 32 bits DMA addressing in any case.
200 	 */
201 
202 	if (!pci_set_dma_mask(pdev, DMA_BIT_MASK(32))) {
203 		endpoint->dma_using_dac = 0;
204 	} else {
205 		dev_err(endpoint->dev, "Failed to set DMA mask. Aborting.\n");
206 		return -ENODEV;
207 	}
208 
209 	return xillybus_endpoint_discovery(endpoint);
210 }
211 
212 static void xilly_remove(struct pci_dev *pdev)
213 {
214 	struct xilly_endpoint *endpoint = pci_get_drvdata(pdev);
215 
216 	xillybus_endpoint_remove(endpoint);
217 }
218 
219 MODULE_DEVICE_TABLE(pci, xillyids);
220 
221 static struct pci_driver xillybus_driver = {
222 	.name = xillyname,
223 	.id_table = xillyids,
224 	.probe = xilly_probe,
225 	.remove = xilly_remove,
226 };
227 
228 module_pci_driver(xillybus_driver);
229