c_can_platform.c revision 8212003260c600b9b55a79634fb29d0f7ec813d9 
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	priv->type = id->driver_data;
186
187	platform_set_drvdata(pdev, dev);
188	SET_NETDEV_DEV(dev, &pdev->dev);
189
190	ret = register_c_can_dev(dev);
191	if (ret) {
192		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
193			KBUILD_MODNAME, ret);
194		goto exit_free_device;
195	}
196
197	dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
198		 KBUILD_MODNAME, priv->base, dev->irq);
199	return 0;
200
201exit_free_device:
202	platform_set_drvdata(pdev, NULL);
203	free_c_can_dev(dev);
204exit_iounmap:
205	iounmap(addr);
206exit_release_mem:
207	release_mem_region(mem->start, resource_size(mem));
208exit_free_clk:
209	clk_put(clk);
210exit:
211	dev_err(&pdev->dev, "probe failed\n");
212
213	return ret;
214}
215
216static int __devexit c_can_plat_remove(struct platform_device *pdev)
217{
218	struct net_device *dev = platform_get_drvdata(pdev);
219	struct c_can_priv *priv = netdev_priv(dev);
220	struct resource *mem;
221
222	unregister_c_can_dev(dev);
223	platform_set_drvdata(pdev, NULL);
224
225	free_c_can_dev(dev);
226	iounmap(priv->base);
227
228	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
229	release_mem_region(mem->start, resource_size(mem));
230
231	clk_put(priv->priv);
232
233	return 0;
234}
235
236#ifdef CONFIG_PM
237static int c_can_suspend(struct platform_device *pdev, pm_message_t state)
238{
239	int ret;
240	struct net_device *ndev = platform_get_drvdata(pdev);
241	struct c_can_priv *priv = netdev_priv(ndev);
242
243	if (priv->type != BOSCH_D_CAN) {
244		dev_warn(&pdev->dev, "Not supported\n");
245		return 0;
246	}
247
248	if (netif_running(ndev)) {
249		netif_stop_queue(ndev);
250		netif_device_detach(ndev);
251	}
252
253	ret = c_can_power_down(ndev);
254	if (ret) {
255		netdev_err(ndev, "failed to enter power down mode\n");
256		return ret;
257	}
258
259	priv->can.state = CAN_STATE_SLEEPING;
260
261	return 0;
262}
263
264static int c_can_resume(struct platform_device *pdev)
265{
266	int ret;
267	struct net_device *ndev = platform_get_drvdata(pdev);
268	struct c_can_priv *priv = netdev_priv(ndev);
269
270	if (priv->type != BOSCH_D_CAN) {
271		dev_warn(&pdev->dev, "Not supported\n");
272		return 0;
273	}
274
275	ret = c_can_power_up(ndev);
276	if (ret) {
277		netdev_err(ndev, "Still in power down mode\n");
278		return ret;
279	}
280
281	priv->can.state = CAN_STATE_ERROR_ACTIVE;
282
283	if (netif_running(ndev)) {
284		netif_device_attach(ndev);
285		netif_start_queue(ndev);
286	}
287
288	return 0;
289}
290#else
291#define c_can_suspend NULL
292#define c_can_resume NULL
293#endif
294
295static struct platform_driver c_can_plat_driver = {
296	.driver = {
297		.name = KBUILD_MODNAME,
298		.owner = THIS_MODULE,
299		.of_match_table = of_match_ptr(c_can_of_table),
300	},
301	.probe = c_can_plat_probe,
302	.remove = __devexit_p(c_can_plat_remove),
303	.suspend = c_can_suspend,
304	.resume = c_can_resume,
305	.id_table = c_can_id_table,
306};
307
308module_platform_driver(c_can_plat_driver);
309
310MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>");
311MODULE_LICENSE("GPL v2");
312MODULE_DESCRIPTION("Platform CAN bus driver for Bosch C_CAN controller");
313