1/*
2 * PCI bus driver for Bosch C_CAN/D_CAN controller
3 *
4 * Copyright (C) 2012 Federico Vaga <federico.vaga@gmail.com>
5 *
6 * Borrowed from c_can_platform.c
7 *
8 * This file is licensed under the terms of the GNU General Public
9 * License version 2. This program is licensed "as is" without any
10 * warranty of any kind, whether express or implied.
11 */
12
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/netdevice.h>
16#include <linux/pci.h>
17
18#include <linux/can/dev.h>
19
20#include "c_can.h"
21
22#define PCI_DEVICE_ID_PCH_CAN 0x8818
23#define PCH_PCI_SOFT_RESET 0x01fc
24
25enum c_can_pci_reg_align {
26 C_CAN_REG_ALIGN_16,
27 C_CAN_REG_ALIGN_32,
28 C_CAN_REG_32,
29};
30
31struct c_can_pci_data {
32 /* Specify if is C_CAN or D_CAN */
33 enum c_can_dev_id type;
34 /* Number of message objects */
35 unsigned int msg_obj_num;
36 /* Set the register alignment in the memory */
37 enum c_can_pci_reg_align reg_align;
38 /* Set the frequency */
39 unsigned int freq;
40 /* PCI bar number */
41 int bar;
42 /* Callback for reset */
43 void (*init)(const struct c_can_priv *priv, bool enable);
44};
45
46/* 16-bit c_can registers can be arranged differently in the memory
47 * architecture of different implementations. For example: 16-bit
48 * registers can be aligned to a 16-bit boundary or 32-bit boundary etc.
49 * Handle the same by providing a common read/write interface.
50 */
51static u16 c_can_pci_read_reg_aligned_to_16bit(const struct c_can_priv *priv,
52 enum reg index)
53{
54 return readw(addr: priv->base + priv->regs[index]);
55}
56
57static void c_can_pci_write_reg_aligned_to_16bit(const struct c_can_priv *priv,
58 enum reg index, u16 val)
59{
60 writew(val, addr: priv->base + priv->regs[index]);
61}
62
63static u16 c_can_pci_read_reg_aligned_to_32bit(const struct c_can_priv *priv,
64 enum reg index)
65{
66 return readw(addr: priv->base + 2 * priv->regs[index]);
67}
68
69static void c_can_pci_write_reg_aligned_to_32bit(const struct c_can_priv *priv,
70 enum reg index, u16 val)
71{
72 writew(val, addr: priv->base + 2 * priv->regs[index]);
73}
74
75static u16 c_can_pci_read_reg_32bit(const struct c_can_priv *priv,
76 enum reg index)
77{
78 return (u16)ioread32(priv->base + 2 * priv->regs[index]);
79}
80
81static void c_can_pci_write_reg_32bit(const struct c_can_priv *priv,
82 enum reg index, u16 val)
83{
84 iowrite32((u32)val, priv->base + 2 * priv->regs[index]);
85}
86
87static u32 c_can_pci_read_reg32(const struct c_can_priv *priv, enum reg index)
88{
89 u32 val;
90
91 val = priv->read_reg(priv, index);
92 val |= ((u32)priv->read_reg(priv, index + 1)) << 16;
93
94 return val;
95}
96
97static void c_can_pci_write_reg32(const struct c_can_priv *priv, enum reg index,
98 u32 val)
99{
100 priv->write_reg(priv, index + 1, val >> 16);
101 priv->write_reg(priv, index, val);
102}
103
104static void c_can_pci_reset_pch(const struct c_can_priv *priv, bool enable)
105{
106 if (enable) {
107 u32 __iomem *addr = priv->base + PCH_PCI_SOFT_RESET;
108
109 /* write to sw reset register */
110 iowrite32(1, addr);
111 iowrite32(0, addr);
112 }
113}
114
115static int c_can_pci_probe(struct pci_dev *pdev,
116 const struct pci_device_id *ent)
117{
118 struct c_can_pci_data *c_can_pci_data = (void *)ent->driver_data;
119 struct c_can_priv *priv;
120 struct net_device *dev;
121 void __iomem *addr;
122 int ret;
123
124 ret = pci_enable_device(dev: pdev);
125 if (ret) {
126 dev_err(&pdev->dev, "pci_enable_device FAILED\n");
127 goto out;
128 }
129
130 ret = pci_request_regions(pdev, KBUILD_MODNAME);
131 if (ret) {
132 dev_err(&pdev->dev, "pci_request_regions FAILED\n");
133 goto out_disable_device;
134 }
135
136 ret = pci_enable_msi(dev: pdev);
137 if (!ret) {
138 dev_info(&pdev->dev, "MSI enabled\n");
139 pci_set_master(dev: pdev);
140 }
141
142 addr = pci_iomap(dev: pdev, bar: c_can_pci_data->bar,
143 pci_resource_len(pdev, c_can_pci_data->bar));
144 if (!addr) {
145 dev_err(&pdev->dev,
146 "device has no PCI memory resources, failing adapter\n");
147 ret = -ENOMEM;
148 goto out_release_regions;
149 }
150
151 /* allocate the c_can device */
152 dev = alloc_c_can_dev(msg_obj_num: c_can_pci_data->msg_obj_num);
153 if (!dev) {
154 ret = -ENOMEM;
155 goto out_iounmap;
156 }
157
158 priv = netdev_priv(dev);
159 pci_set_drvdata(pdev, data: dev);
160 SET_NETDEV_DEV(dev, &pdev->dev);
161
162 dev->irq = pdev->irq;
163 priv->base = addr;
164 priv->device = &pdev->dev;
165
166 if (!c_can_pci_data->freq) {
167 dev_err(&pdev->dev, "no clock frequency defined\n");
168 ret = -ENODEV;
169 goto out_free_c_can;
170 } else {
171 priv->can.clock.freq = c_can_pci_data->freq;
172 }
173
174 /* Configure CAN type */
175 switch (c_can_pci_data->type) {
176 case BOSCH_C_CAN:
177 priv->regs = reg_map_c_can;
178 break;
179 case BOSCH_D_CAN:
180 priv->regs = reg_map_d_can;
181 break;
182 default:
183 ret = -EINVAL;
184 goto out_free_c_can;
185 }
186
187 priv->type = c_can_pci_data->type;
188
189 /* Configure access to registers */
190 switch (c_can_pci_data->reg_align) {
191 case C_CAN_REG_ALIGN_32:
192 priv->read_reg = c_can_pci_read_reg_aligned_to_32bit;
193 priv->write_reg = c_can_pci_write_reg_aligned_to_32bit;
194 break;
195 case C_CAN_REG_ALIGN_16:
196 priv->read_reg = c_can_pci_read_reg_aligned_to_16bit;
197 priv->write_reg = c_can_pci_write_reg_aligned_to_16bit;
198 break;
199 case C_CAN_REG_32:
200 priv->read_reg = c_can_pci_read_reg_32bit;
201 priv->write_reg = c_can_pci_write_reg_32bit;
202 break;
203 default:
204 ret = -EINVAL;
205 goto out_free_c_can;
206 }
207 priv->read_reg32 = c_can_pci_read_reg32;
208 priv->write_reg32 = c_can_pci_write_reg32;
209
210 priv->raminit = c_can_pci_data->init;
211
212 ret = register_c_can_dev(dev);
213 if (ret) {
214 dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
215 KBUILD_MODNAME, ret);
216 goto out_free_c_can;
217 }
218
219 dev_dbg(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
220 KBUILD_MODNAME, priv->regs, dev->irq);
221
222 return 0;
223
224out_free_c_can:
225 free_c_can_dev(dev);
226out_iounmap:
227 pci_iounmap(dev: pdev, addr);
228out_release_regions:
229 pci_disable_msi(dev: pdev);
230 pci_release_regions(pdev);
231out_disable_device:
232 pci_disable_device(dev: pdev);
233out:
234 return ret;
235}
236
237static void c_can_pci_remove(struct pci_dev *pdev)
238{
239 struct net_device *dev = pci_get_drvdata(pdev);
240 struct c_can_priv *priv = netdev_priv(dev);
241 void __iomem *addr = priv->base;
242
243 unregister_c_can_dev(dev);
244
245 free_c_can_dev(dev);
246
247 pci_iounmap(dev: pdev, addr);
248 pci_disable_msi(dev: pdev);
249 pci_release_regions(pdev);
250 pci_disable_device(dev: pdev);
251}
252
253static const struct c_can_pci_data c_can_sta2x11 = {
254 .type = BOSCH_C_CAN,
255 .msg_obj_num = 32,
256 .reg_align = C_CAN_REG_ALIGN_32,
257 .freq = 52000000, /* 52 Mhz */
258 .bar = 0,
259};
260
261static const struct c_can_pci_data c_can_pch = {
262 .type = BOSCH_C_CAN,
263 .msg_obj_num = 32,
264 .reg_align = C_CAN_REG_32,
265 .freq = 50000000, /* 50 MHz */
266 .init = c_can_pci_reset_pch,
267 .bar = 1,
268};
269
270#define C_CAN_ID(_vend, _dev, _driverdata) { \
271 PCI_DEVICE(_vend, _dev), \
272 .driver_data = (unsigned long)&(_driverdata), \
273}
274
275static const struct pci_device_id c_can_pci_tbl[] = {
276 C_CAN_ID(PCI_VENDOR_ID_STMICRO, PCI_DEVICE_ID_STMICRO_CAN,
277 c_can_sta2x11),
278 C_CAN_ID(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_PCH_CAN,
279 c_can_pch),
280 {},
281};
282
283static struct pci_driver c_can_pci_driver = {
284 .name = KBUILD_MODNAME,
285 .id_table = c_can_pci_tbl,
286 .probe = c_can_pci_probe,
287 .remove = c_can_pci_remove,
288};
289
290module_pci_driver(c_can_pci_driver);
291
292MODULE_AUTHOR("Federico Vaga <federico.vaga@gmail.com>");
293MODULE_LICENSE("GPL v2");
294MODULE_DESCRIPTION("PCI CAN bus driver for Bosch C_CAN/D_CAN controller");
295MODULE_DEVICE_TABLE(pci, c_can_pci_tbl);
296

source code of linux/drivers/net/can/c_can/c_can_pci.c