c_can_platform.c revision 4570a5248bafd9d06d31ab6f6ef337c90a2a4bc0 
1/*
2 * Platform CAN bus driver for Bosch C_CAN controller
3 *
4 * Copyright (C) 2010 ST Microelectronics
5 * Bhupesh Sharma <bhupesh.sharma@st.com>
6 *
7 * Borrowed heavily from the C_CAN driver originally written by:
8 * Copyright (C) 2007
9 * - Sascha Hauer, Marc Kleine-Budde, Pengutronix <s.hauer@pengutronix.de>
10 * - Simon Kallweit, intefo AG <simon.kallweit@intefo.ch>
11 *
12 * Bosch C_CAN controller is compliant to CAN protocol version 2.0 part A and B.
13 * Bosch C_CAN user manual can be obtained from:
14 * http://www.semiconductors.bosch.de/media/en/pdf/ipmodules_1/c_can/
15 * users_manual_c_can.pdf
16 *
17 * This file is licensed under the terms of the GNU General Public
18 * License version 2. This program is licensed "as is" without any
19 * warranty of any kind, whether express or implied.
20 */
21
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/interrupt.h>
25#include <linux/delay.h>
26#include <linux/netdevice.h>
27#include <linux/if_arp.h>
28#include <linux/if_ether.h>
29#include <linux/list.h>
30#include <linux/io.h>
31#include <linux/platform_device.h>
32#include <linux/clk.h>
33
34#include <linux/can/dev.h>
35
36#include "c_can.h"
37
38/*
39 * 16-bit c_can registers can be arranged differently in the memory
40 * architecture of different implementations. For example: 16-bit
41 * registers can be aligned to a 16-bit boundary or 32-bit boundary etc.
42 * Handle the same by providing a common read/write interface.
43 */
44static u16 c_can_plat_read_reg_aligned_to_16bit(struct c_can_priv *priv,
45						void *reg)
46{
47	return readw(reg);
48}
49
50static void c_can_plat_write_reg_aligned_to_16bit(struct c_can_priv *priv,
51						void *reg, u16 val)
52{
53	writew(val, reg);
54}
55
56static u16 c_can_plat_read_reg_aligned_to_32bit(struct c_can_priv *priv,
57						void *reg)
58{
59	return readw(reg + (long)reg - (long)priv->regs);
60}
61
62static void c_can_plat_write_reg_aligned_to_32bit(struct c_can_priv *priv,
63						void *reg, u16 val)
64{
65	writew(val, reg + (long)reg - (long)priv->regs);
66}
67
68static int __devinit c_can_plat_probe(struct platform_device *pdev)
69{
70	int ret;
71	void __iomem *addr;
72	struct net_device *dev;
73	struct c_can_priv *priv;
74	struct resource *mem;
75	int irq;
76#ifdef CONFIG_HAVE_CLK
77	struct clk *clk;
78
79	/* get the appropriate clk */
80	clk = clk_get(&pdev->dev, NULL);
81	if (IS_ERR(clk)) {
82		dev_err(&pdev->dev, "no clock defined\n");
83		ret = -ENODEV;
84		goto exit;
85	}
86#endif
87
88	/* get the platform data */
89	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
90	irq = platform_get_irq(pdev, 0);
91	if (!mem || irq <= 0) {
92		ret = -ENODEV;
93		goto exit_free_clk;
94	}
95
96	if (!request_mem_region(mem->start, resource_size(mem),
97				KBUILD_MODNAME)) {
98		dev_err(&pdev->dev, "resource unavailable\n");
99		ret = -ENODEV;
100		goto exit_free_clk;
101	}
102
103	addr = ioremap(mem->start, resource_size(mem));
104	if (!addr) {
105		dev_err(&pdev->dev, "failed to map can port\n");
106		ret = -ENOMEM;
107		goto exit_release_mem;
108	}
109
110	/* allocate the c_can device */
111	dev = alloc_c_can_dev();
112	if (!dev) {
113		ret = -ENOMEM;
114		goto exit_iounmap;
115	}
116
117	priv = netdev_priv(dev);
118
119	dev->irq = irq;
120	priv->regs = addr;
121#ifdef CONFIG_HAVE_CLK
122	priv->can.clock.freq = clk_get_rate(clk);
123	priv->priv = clk;
124#endif
125
126	switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) {
127	case IORESOURCE_MEM_32BIT:
128		priv->read_reg = c_can_plat_read_reg_aligned_to_32bit;
129		priv->write_reg = c_can_plat_write_reg_aligned_to_32bit;
130		break;
131	case IORESOURCE_MEM_16BIT:
132	default:
133		priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
134		priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
135		break;
136	}
137
138	platform_set_drvdata(pdev, dev);
139	SET_NETDEV_DEV(dev, &pdev->dev);
140
141	ret = register_c_can_dev(dev);
142	if (ret) {
143		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
144			KBUILD_MODNAME, ret);
145		goto exit_free_device;
146	}
147
148	dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
149		 KBUILD_MODNAME, priv->regs, dev->irq);
150	return 0;
151
152exit_free_device:
153	platform_set_drvdata(pdev, NULL);
154	free_c_can_dev(dev);
155exit_iounmap:
156	iounmap(addr);
157exit_release_mem:
158	release_mem_region(mem->start, resource_size(mem));
159exit_free_clk:
160#ifdef CONFIG_HAVE_CLK
161	clk_put(clk);
162exit:
163#endif
164	dev_err(&pdev->dev, "probe failed\n");
165
166	return ret;
167}
168
169static int __devexit c_can_plat_remove(struct platform_device *pdev)
170{
171	struct net_device *dev = platform_get_drvdata(pdev);
172	struct c_can_priv *priv = netdev_priv(dev);
173	struct resource *mem;
174
175	unregister_c_can_dev(dev);
176	platform_set_drvdata(pdev, NULL);
177
178	free_c_can_dev(dev);
179	iounmap(priv->regs);
180
181	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
182	release_mem_region(mem->start, resource_size(mem));
183
184#ifdef CONFIG_HAVE_CLK
185	clk_put(priv->priv);
186#endif
187
188	return 0;
189}
190
191static struct platform_driver c_can_plat_driver = {
192	.driver = {
193		.name = KBUILD_MODNAME,
194		.owner = THIS_MODULE,
195	},
196	.probe = c_can_plat_probe,
197	.remove = __devexit_p(c_can_plat_remove),
198};
199
200static int __init c_can_plat_init(void)
201{
202	return platform_driver_register(&c_can_plat_driver);
203}
204module_init(c_can_plat_init);
205
206static void __exit c_can_plat_exit(void)
207{
208	platform_driver_unregister(&c_can_plat_driver);
209}
210module_exit(c_can_plat_exit);
211
212MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>");
213MODULE_LICENSE("GPL v2");
214MODULE_DESCRIPTION("Platform CAN bus driver for Bosch C_CAN controller");
215