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_ACTEL		0x11aa
28 #define PCI_VENDOR_ID_LATTICE		0x1204
29 
30 static const char xillyname[] = "xillybus_pcie";
31 
32 static const struct pci_device_id xillyids[] = {
33 	{PCI_DEVICE(PCI_VENDOR_ID_XILINX, PCI_DEVICE_ID_XILLYBUS)},
34 	{PCI_DEVICE(PCI_VENDOR_ID_ALTERA, PCI_DEVICE_ID_XILLYBUS)},
35 	{PCI_DEVICE(PCI_VENDOR_ID_ACTEL, PCI_DEVICE_ID_XILLYBUS)},
36 	{PCI_DEVICE(PCI_VENDOR_ID_LATTICE, PCI_DEVICE_ID_XILLYBUS)},
37 	{ /* End: all zeroes */ }
38 };
39 
40 static int xilly_pci_direction(int direction)
41 {
42 	switch (direction) {
43 	case DMA_TO_DEVICE:
44 		return PCI_DMA_TODEVICE;
45 	case DMA_FROM_DEVICE:
46 		return PCI_DMA_FROMDEVICE;
47 	default:
48 		return PCI_DMA_BIDIRECTIONAL;
49 	}
50 }
51 
52 static void xilly_dma_sync_single_for_cpu_pci(struct xilly_endpoint *ep,
53 					      dma_addr_t dma_handle,
54 					      size_t size,
55 					      int direction)
56 {
57 	pci_dma_sync_single_for_cpu(ep->pdev,
58 				    dma_handle,
59 				    size,
60 				    xilly_pci_direction(direction));
61 }
62 
63 static void xilly_dma_sync_single_for_device_pci(struct xilly_endpoint *ep,
64 						 dma_addr_t dma_handle,
65 						 size_t size,
66 						 int direction)
67 {
68 	pci_dma_sync_single_for_device(ep->pdev,
69 				       dma_handle,
70 				       size,
71 				       xilly_pci_direction(direction));
72 }
73 
74 static void xilly_pci_unmap(void *ptr)
75 {
76 	struct xilly_mapping *data = ptr;
77 
78 	pci_unmap_single(data->device, data->dma_addr,
79 			 data->size, data->direction);
80 
81 	kfree(ptr);
82 }
83 
84 /*
85  * Map either through the PCI DMA mapper or the non_PCI one. Behind the
86  * scenes exactly the same functions are called with the same parameters,
87  * but that can change.
88  */
89 
90 static int xilly_map_single_pci(struct xilly_endpoint *ep,
91 				void *ptr,
92 				size_t size,
93 				int direction,
94 				dma_addr_t *ret_dma_handle
95 	)
96 {
97 	int pci_direction;
98 	dma_addr_t addr;
99 	struct xilly_mapping *this;
100 
101 	this = kzalloc(sizeof(*this), GFP_KERNEL);
102 	if (!this)
103 		return -ENOMEM;
104 
105 	pci_direction = xilly_pci_direction(direction);
106 
107 	addr = pci_map_single(ep->pdev, ptr, size, pci_direction);
108 
109 	if (pci_dma_mapping_error(ep->pdev, addr)) {
110 		kfree(this);
111 		return -ENODEV;
112 	}
113 
114 	this->device = ep->pdev;
115 	this->dma_addr = addr;
116 	this->size = size;
117 	this->direction = pci_direction;
118 
119 	*ret_dma_handle = addr;
120 
121 	return devm_add_action_or_reset(ep->dev, xilly_pci_unmap, this);
122 }
123 
124 static struct xilly_endpoint_hardware pci_hw = {
125 	.owner = THIS_MODULE,
126 	.hw_sync_sgl_for_cpu = xilly_dma_sync_single_for_cpu_pci,
127 	.hw_sync_sgl_for_device = xilly_dma_sync_single_for_device_pci,
128 	.map_single = xilly_map_single_pci,
129 };
130 
131 static int xilly_probe(struct pci_dev *pdev,
132 		       const struct pci_device_id *ent)
133 {
134 	struct xilly_endpoint *endpoint;
135 	int rc;
136 
137 	endpoint = xillybus_init_endpoint(pdev, &pdev->dev, &pci_hw);
138 
139 	if (!endpoint)
140 		return -ENOMEM;
141 
142 	pci_set_drvdata(pdev, endpoint);
143 
144 	rc = pcim_enable_device(pdev);
145 	if (rc) {
146 		dev_err(endpoint->dev,
147 			"pcim_enable_device() failed. Aborting.\n");
148 		return rc;
149 	}
150 
151 	/* L0s has caused packet drops. No power saving, thank you. */
152 
153 	pci_disable_link_state(pdev, PCIE_LINK_STATE_L0S);
154 
155 	if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM)) {
156 		dev_err(endpoint->dev,
157 			"Incorrect BAR configuration. Aborting.\n");
158 		return -ENODEV;
159 	}
160 
161 	rc = pcim_iomap_regions(pdev, 0x01, xillyname);
162 	if (rc) {
163 		dev_err(endpoint->dev,
164 			"pcim_iomap_regions() failed. Aborting.\n");
165 		return rc;
166 	}
167 
168 	endpoint->registers = pcim_iomap_table(pdev)[0];
169 
170 	pci_set_master(pdev);
171 
172 	/* Set up a single MSI interrupt */
173 	if (pci_enable_msi(pdev)) {
174 		dev_err(endpoint->dev,
175 			"Failed to enable MSI interrupts. Aborting.\n");
176 		return -ENODEV;
177 	}
178 	rc = devm_request_irq(&pdev->dev, pdev->irq, xillybus_isr, 0,
179 			      xillyname, endpoint);
180 	if (rc) {
181 		dev_err(endpoint->dev,
182 			"Failed to register MSI handler. Aborting.\n");
183 		return -ENODEV;
184 	}
185 
186 	/*
187 	 * Some (old and buggy?) hardware drops 64-bit addressed PCIe packets,
188 	 * even when the PCIe driver claims that a 64-bit mask is OK. On the
189 	 * other hand, on some architectures, 64-bit addressing is mandatory.
190 	 * So go for the 64-bit mask only when failing is the other option.
191 	 */
192 
193 	if (!pci_set_dma_mask(pdev, DMA_BIT_MASK(32))) {
194 		endpoint->dma_using_dac = 0;
195 	} else if (!pci_set_dma_mask(pdev, DMA_BIT_MASK(64))) {
196 		endpoint->dma_using_dac = 1;
197 	} else {
198 		dev_err(endpoint->dev, "Failed to set DMA mask. Aborting.\n");
199 		return -ENODEV;
200 	}
201 
202 	return xillybus_endpoint_discovery(endpoint);
203 }
204 
205 static void xilly_remove(struct pci_dev *pdev)
206 {
207 	struct xilly_endpoint *endpoint = pci_get_drvdata(pdev);
208 
209 	xillybus_endpoint_remove(endpoint);
210 }
211 
212 MODULE_DEVICE_TABLE(pci, xillyids);
213 
214 static struct pci_driver xillybus_driver = {
215 	.name = xillyname,
216 	.id_table = xillyids,
217 	.probe = xilly_probe,
218 	.remove = xilly_remove,
219 };
220 
221 module_pci_driver(xillybus_driver);
222