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
19MODULE_DESCRIPTION("Xillybus driver for PCIe");
20MODULE_AUTHOR("Eli Billauer, Xillybus Ltd.");
21MODULE_VERSION("1.06");
22MODULE_ALIAS("xillybus_pcie");
23MODULE_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
31static const char xillyname[] = "xillybus_pcie";
32
33static 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
41static 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
53static 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
64static 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
75static 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
91static 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
133static 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
140static 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
212static 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
219MODULE_DEVICE_TABLE(pci, xillyids);
220
221static struct pci_driver xillybus_driver = {
222	.name = xillyname,
223	.id_table = xillyids,
224	.probe = xilly_probe,
225	.remove = xilly_remove,
226};
227
228module_pci_driver(xillybus_driver);
229