c_can_platform.c revision 4cdd34b26826e89972c03043987b83f76e7ad510 
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#include <linux/of.h>
34#include <linux/of_device.h>
35
36#include <linux/can/dev.h>
37
38#include "c_can.h"
39
40/*
41 * 16-bit c_can registers can be arranged differently in the memory
42 * architecture of different implementations. For example: 16-bit
43 * registers can be aligned to a 16-bit boundary or 32-bit boundary etc.
44 * Handle the same by providing a common read/write interface.
45 */
46static u16 c_can_plat_read_reg_aligned_to_16bit(struct c_can_priv *priv,
47						enum reg index)
48{
49	return readw(priv->base + priv->regs[index]);
50}
51
52static void c_can_plat_write_reg_aligned_to_16bit(struct c_can_priv *priv,
53						enum reg index, u16 val)
54{
55	writew(val, priv->base + priv->regs[index]);
56}
57
58static u16 c_can_plat_read_reg_aligned_to_32bit(struct c_can_priv *priv,
59						enum reg index)
60{
61	return readw(priv->base + 2 * priv->regs[index]);
62}
63
64static void c_can_plat_write_reg_aligned_to_32bit(struct c_can_priv *priv,
65						enum reg index, u16 val)
66{
67	writew(val, priv->base + 2 * priv->regs[index]);
68}
69
70static struct platform_device_id c_can_id_table[] = {
71	[BOSCH_C_CAN_PLATFORM] = {
72		.name = KBUILD_MODNAME,
73		.driver_data = BOSCH_C_CAN,
74	},
75	[BOSCH_C_CAN] = {
76		.name = "c_can",
77		.driver_data = BOSCH_C_CAN,
78	},
79	[BOSCH_D_CAN] = {
80		.name = "d_can",
81		.driver_data = BOSCH_D_CAN,
82	}, {
83	}
84};
85
86static const struct of_device_id c_can_of_table[] = {
87	{ .compatible = "bosch,c_can", .data = &c_can_id_table[BOSCH_C_CAN] },
88	{ .compatible = "bosch,d_can", .data = &c_can_id_table[BOSCH_D_CAN] },
89	{ /* sentinel */ },
90};
91
92static int __devinit c_can_plat_probe(struct platform_device *pdev)
93{
94	int ret;
95	void __iomem *addr;
96	struct net_device *dev;
97	struct c_can_priv *priv;
98	const struct of_device_id *match;
99	const struct platform_device_id *id;
100	struct resource *mem;
101	int irq;
102	struct clk *clk;
103
104	if (pdev->dev.of_node) {
105		match = of_match_device(c_can_of_table, &pdev->dev);
106		if (!match) {
107			dev_err(&pdev->dev, "Failed to find matching dt id\n");
108			ret = -EINVAL;
109			goto exit;
110		}
111		id = match->data;
112	} else {
113		id = platform_get_device_id(pdev);
114	}
115
116	/* get the appropriate clk */
117	clk = clk_get(&pdev->dev, NULL);
118	if (IS_ERR(clk)) {
119		dev_err(&pdev->dev, "no clock defined\n");
120		ret = -ENODEV;
121		goto exit;
122	}
123
124	/* get the platform data */
125	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
126	irq = platform_get_irq(pdev, 0);
127	if (!mem || irq <= 0) {
128		ret = -ENODEV;
129		goto exit_free_clk;
130	}
131
132	if (!request_mem_region(mem->start, resource_size(mem),
133				KBUILD_MODNAME)) {
134		dev_err(&pdev->dev, "resource unavailable\n");
135		ret = -ENODEV;
136		goto exit_free_clk;
137	}
138
139	addr = ioremap(mem->start, resource_size(mem));
140	if (!addr) {
141		dev_err(&pdev->dev, "failed to map can port\n");
142		ret = -ENOMEM;
143		goto exit_release_mem;
144	}
145
146	/* allocate the c_can device */
147	dev = alloc_c_can_dev();
148	if (!dev) {
149		ret = -ENOMEM;
150		goto exit_iounmap;
151	}
152
153	priv = netdev_priv(dev);
154	switch (id->driver_data) {
155	case BOSCH_C_CAN:
156		priv->regs = reg_map_c_can;
157		switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) {
158		case IORESOURCE_MEM_32BIT:
159			priv->read_reg = c_can_plat_read_reg_aligned_to_32bit;
160			priv->write_reg = c_can_plat_write_reg_aligned_to_32bit;
161			break;
162		case IORESOURCE_MEM_16BIT:
163		default:
164			priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
165			priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
166			break;
167		}
168		break;
169	case BOSCH_D_CAN:
170		priv->regs = reg_map_d_can;
171		priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
172		priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
173		priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
174		break;
175	default:
176		ret = -EINVAL;
177		goto exit_free_device;
178	}
179
180	dev->irq = irq;
181	priv->base = addr;
182	priv->device = &pdev->dev;
183	priv->can.clock.freq = clk_get_rate(clk);
184	priv->priv = clk;
185
186	platform_set_drvdata(pdev, dev);
187	SET_NETDEV_DEV(dev, &pdev->dev);
188
189	ret = register_c_can_dev(dev);
190	if (ret) {
191		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
192			KBUILD_MODNAME, ret);
193		goto exit_free_device;
194	}
195
196	dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
197		 KBUILD_MODNAME, priv->base, dev->irq);
198	return 0;
199
200exit_free_device:
201	platform_set_drvdata(pdev, NULL);
202	free_c_can_dev(dev);
203exit_iounmap:
204	iounmap(addr);
205exit_release_mem:
206	release_mem_region(mem->start, resource_size(mem));
207exit_free_clk:
208	clk_put(clk);
209exit:
210	dev_err(&pdev->dev, "probe failed\n");
211
212	return ret;
213}
214
215static int __devexit c_can_plat_remove(struct platform_device *pdev)
216{
217	struct net_device *dev = platform_get_drvdata(pdev);
218	struct c_can_priv *priv = netdev_priv(dev);
219	struct resource *mem;
220
221	unregister_c_can_dev(dev);
222	platform_set_drvdata(pdev, NULL);
223
224	free_c_can_dev(dev);
225	iounmap(priv->base);
226
227	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
228	release_mem_region(mem->start, resource_size(mem));
229
230	clk_put(priv->priv);
231
232	return 0;
233}
234
235static struct platform_driver c_can_plat_driver = {
236	.driver = {
237		.name = KBUILD_MODNAME,
238		.owner = THIS_MODULE,
239		.of_match_table = of_match_ptr(c_can_of_table),
240	},
241	.probe = c_can_plat_probe,
242	.remove = __devexit_p(c_can_plat_remove),
243	.id_table = c_can_id_table,
244};
245
246module_platform_driver(c_can_plat_driver);
247
248MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>");
249MODULE_LICENSE("GPL v2");
250MODULE_DESCRIPTION("Platform CAN bus driver for Bosch C_CAN controller");
251