c_can_platform.c revision 6439fbce1075dedfe23165c136f19f44c00ca132 
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#define CAN_RAMINIT_START_MASK(i)	(1 << (i))
41
42/*
43 * 16-bit c_can registers can be arranged differently in the memory
44 * architecture of different implementations. For example: 16-bit
45 * registers can be aligned to a 16-bit boundary or 32-bit boundary etc.
46 * Handle the same by providing a common read/write interface.
47 */
48static u16 c_can_plat_read_reg_aligned_to_16bit(struct c_can_priv *priv,
49						enum reg index)
50{
51	return readw(priv->base + priv->regs[index]);
52}
53
54static void c_can_plat_write_reg_aligned_to_16bit(struct c_can_priv *priv,
55						enum reg index, u16 val)
56{
57	writew(val, priv->base + priv->regs[index]);
58}
59
60static u16 c_can_plat_read_reg_aligned_to_32bit(struct c_can_priv *priv,
61						enum reg index)
62{
63	return readw(priv->base + 2 * priv->regs[index]);
64}
65
66static void c_can_plat_write_reg_aligned_to_32bit(struct c_can_priv *priv,
67						enum reg index, u16 val)
68{
69	writew(val, priv->base + 2 * priv->regs[index]);
70}
71
72static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
73{
74	u32 val;
75
76	val = readl(priv->raminit_ctrlreg);
77	if (enable)
78		val |= CAN_RAMINIT_START_MASK(priv->instance);
79	else
80		val &= ~CAN_RAMINIT_START_MASK(priv->instance);
81	writel(val, priv->raminit_ctrlreg);
82}
83
84static struct platform_device_id c_can_id_table[] = {
85	[BOSCH_C_CAN_PLATFORM] = {
86		.name = KBUILD_MODNAME,
87		.driver_data = BOSCH_C_CAN,
88	},
89	[BOSCH_C_CAN] = {
90		.name = "c_can",
91		.driver_data = BOSCH_C_CAN,
92	},
93	[BOSCH_D_CAN] = {
94		.name = "d_can",
95		.driver_data = BOSCH_D_CAN,
96	}, {
97	}
98};
99MODULE_DEVICE_TABLE(platform, c_can_id_table);
100
101static const struct of_device_id c_can_of_table[] = {
102	{ .compatible = "bosch,c_can", .data = &c_can_id_table[BOSCH_C_CAN] },
103	{ .compatible = "bosch,d_can", .data = &c_can_id_table[BOSCH_D_CAN] },
104	{ /* sentinel */ },
105};
106MODULE_DEVICE_TABLE(of, c_can_of_table);
107
108static int c_can_plat_probe(struct platform_device *pdev)
109{
110	int ret;
111	void __iomem *addr;
112	struct net_device *dev;
113	struct c_can_priv *priv;
114	const struct of_device_id *match;
115	const struct platform_device_id *id;
116	struct resource *mem, *res;
117	int irq;
118	struct clk *clk;
119
120	if (pdev->dev.of_node) {
121		match = of_match_device(c_can_of_table, &pdev->dev);
122		if (!match) {
123			dev_err(&pdev->dev, "Failed to find matching dt id\n");
124			ret = -EINVAL;
125			goto exit;
126		}
127		id = match->data;
128	} else {
129		id = platform_get_device_id(pdev);
130	}
131
132	/* get the appropriate clk */
133	clk = clk_get(&pdev->dev, NULL);
134	if (IS_ERR(clk)) {
135		dev_err(&pdev->dev, "no clock defined\n");
136		ret = -ENODEV;
137		goto exit;
138	}
139
140	/* get the platform data */
141	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
142	irq = platform_get_irq(pdev, 0);
143	if (!mem || irq <= 0) {
144		ret = -ENODEV;
145		goto exit_free_clk;
146	}
147
148	if (!request_mem_region(mem->start, resource_size(mem),
149				KBUILD_MODNAME)) {
150		dev_err(&pdev->dev, "resource unavailable\n");
151		ret = -ENODEV;
152		goto exit_free_clk;
153	}
154
155	addr = ioremap(mem->start, resource_size(mem));
156	if (!addr) {
157		dev_err(&pdev->dev, "failed to map can port\n");
158		ret = -ENOMEM;
159		goto exit_release_mem;
160	}
161
162	/* allocate the c_can device */
163	dev = alloc_c_can_dev();
164	if (!dev) {
165		ret = -ENOMEM;
166		goto exit_iounmap;
167	}
168
169	priv = netdev_priv(dev);
170	switch (id->driver_data) {
171	case BOSCH_C_CAN:
172		priv->regs = reg_map_c_can;
173		switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) {
174		case IORESOURCE_MEM_32BIT:
175			priv->read_reg = c_can_plat_read_reg_aligned_to_32bit;
176			priv->write_reg = c_can_plat_write_reg_aligned_to_32bit;
177			break;
178		case IORESOURCE_MEM_16BIT:
179		default:
180			priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
181			priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
182			break;
183		}
184		break;
185	case BOSCH_D_CAN:
186		priv->regs = reg_map_d_can;
187		priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
188		priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
189		priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
190
191		if (pdev->dev.of_node)
192			priv->instance = of_alias_get_id(pdev->dev.of_node, "d_can");
193		else
194			priv->instance = pdev->id;
195
196		res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
197		priv->raminit_ctrlreg = devm_ioremap_resource(&pdev->dev, res);
198		if (IS_ERR(priv->raminit_ctrlreg) || (int)priv->instance < 0)
199			dev_info(&pdev->dev, "control memory is not used for raminit\n");
200		else
201			priv->raminit = c_can_hw_raminit;
202		break;
203	default:
204		ret = -EINVAL;
205		goto exit_free_device;
206	}
207
208	dev->irq = irq;
209	priv->base = addr;
210	priv->device = &pdev->dev;
211	priv->can.clock.freq = clk_get_rate(clk);
212	priv->priv = clk;
213	priv->type = id->driver_data;
214
215	platform_set_drvdata(pdev, dev);
216	SET_NETDEV_DEV(dev, &pdev->dev);
217
218	ret = register_c_can_dev(dev);
219	if (ret) {
220		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
221			KBUILD_MODNAME, ret);
222		goto exit_free_device;
223	}
224
225	dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
226		 KBUILD_MODNAME, priv->base, dev->irq);
227	return 0;
228
229exit_free_device:
230	free_c_can_dev(dev);
231exit_iounmap:
232	iounmap(addr);
233exit_release_mem:
234	release_mem_region(mem->start, resource_size(mem));
235exit_free_clk:
236	clk_put(clk);
237exit:
238	dev_err(&pdev->dev, "probe failed\n");
239
240	return ret;
241}
242
243static int c_can_plat_remove(struct platform_device *pdev)
244{
245	struct net_device *dev = platform_get_drvdata(pdev);
246	struct c_can_priv *priv = netdev_priv(dev);
247	struct resource *mem;
248
249	unregister_c_can_dev(dev);
250
251	free_c_can_dev(dev);
252	iounmap(priv->base);
253
254	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
255	release_mem_region(mem->start, resource_size(mem));
256
257	clk_put(priv->priv);
258
259	return 0;
260}
261
262#ifdef CONFIG_PM
263static int c_can_suspend(struct platform_device *pdev, pm_message_t state)
264{
265	int ret;
266	struct net_device *ndev = platform_get_drvdata(pdev);
267	struct c_can_priv *priv = netdev_priv(ndev);
268
269	if (priv->type != BOSCH_D_CAN) {
270		dev_warn(&pdev->dev, "Not supported\n");
271		return 0;
272	}
273
274	if (netif_running(ndev)) {
275		netif_stop_queue(ndev);
276		netif_device_detach(ndev);
277	}
278
279	ret = c_can_power_down(ndev);
280	if (ret) {
281		netdev_err(ndev, "failed to enter power down mode\n");
282		return ret;
283	}
284
285	priv->can.state = CAN_STATE_SLEEPING;
286
287	return 0;
288}
289
290static int c_can_resume(struct platform_device *pdev)
291{
292	int ret;
293	struct net_device *ndev = platform_get_drvdata(pdev);
294	struct c_can_priv *priv = netdev_priv(ndev);
295
296	if (priv->type != BOSCH_D_CAN) {
297		dev_warn(&pdev->dev, "Not supported\n");
298		return 0;
299	}
300
301	ret = c_can_power_up(ndev);
302	if (ret) {
303		netdev_err(ndev, "Still in power down mode\n");
304		return ret;
305	}
306
307	priv->can.state = CAN_STATE_ERROR_ACTIVE;
308
309	if (netif_running(ndev)) {
310		netif_device_attach(ndev);
311		netif_start_queue(ndev);
312	}
313
314	return 0;
315}
316#else
317#define c_can_suspend NULL
318#define c_can_resume NULL
319#endif
320
321static struct platform_driver c_can_plat_driver = {
322	.driver = {
323		.name = KBUILD_MODNAME,
324		.owner = THIS_MODULE,
325		.of_match_table = of_match_ptr(c_can_of_table),
326	},
327	.probe = c_can_plat_probe,
328	.remove = c_can_plat_remove,
329	.suspend = c_can_suspend,
330	.resume = c_can_resume,
331	.id_table = c_can_id_table,
332};
333
334module_platform_driver(c_can_plat_driver);
335
336MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>");
337MODULE_LICENSE("GPL v2");
338MODULE_DESCRIPTION("Platform CAN bus driver for Bosch C_CAN controller");
339