c_can_platform.c revision 52cde85acc23f61b09dd0376c61eb891125c6990 
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#include <linux/pinctrl/consumer.h>
36
37#include <linux/can/dev.h>
38
39#include "c_can.h"
40
41#define CAN_RAMINIT_START_MASK(i)	(1 << (i))
42
43/*
44 * 16-bit c_can registers can be arranged differently in the memory
45 * architecture of different implementations. For example: 16-bit
46 * registers can be aligned to a 16-bit boundary or 32-bit boundary etc.
47 * Handle the same by providing a common read/write interface.
48 */
49static u16 c_can_plat_read_reg_aligned_to_16bit(struct c_can_priv *priv,
50						enum reg index)
51{
52	return readw(priv->base + priv->regs[index]);
53}
54
55static void c_can_plat_write_reg_aligned_to_16bit(struct c_can_priv *priv,
56						enum reg index, u16 val)
57{
58	writew(val, priv->base + priv->regs[index]);
59}
60
61static u16 c_can_plat_read_reg_aligned_to_32bit(struct c_can_priv *priv,
62						enum reg index)
63{
64	return readw(priv->base + 2 * priv->regs[index]);
65}
66
67static void c_can_plat_write_reg_aligned_to_32bit(struct c_can_priv *priv,
68						enum reg index, u16 val)
69{
70	writew(val, priv->base + 2 * priv->regs[index]);
71}
72
73static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
74{
75	u32 val;
76
77	val = readl(priv->raminit_ctrlreg);
78	if (enable)
79		val |= CAN_RAMINIT_START_MASK(priv->instance);
80	else
81		val &= ~CAN_RAMINIT_START_MASK(priv->instance);
82	writel(val, priv->raminit_ctrlreg);
83}
84
85static struct platform_device_id c_can_id_table[] = {
86	[BOSCH_C_CAN_PLATFORM] = {
87		.name = KBUILD_MODNAME,
88		.driver_data = BOSCH_C_CAN,
89	},
90	[BOSCH_C_CAN] = {
91		.name = "c_can",
92		.driver_data = BOSCH_C_CAN,
93	},
94	[BOSCH_D_CAN] = {
95		.name = "d_can",
96		.driver_data = BOSCH_D_CAN,
97	}, {
98	}
99};
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};
106
107static int __devinit c_can_plat_probe(struct platform_device *pdev)
108{
109	int ret;
110	void __iomem *addr;
111	struct net_device *dev;
112	struct c_can_priv *priv;
113	const struct of_device_id *match;
114	const struct platform_device_id *id;
115	struct pinctrl *pinctrl;
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	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
133	if (IS_ERR(pinctrl))
134		dev_warn(&pdev->dev,
135			"failed to configure pins from driver\n");
136
137	/* get the appropriate clk */
138	clk = clk_get(&pdev->dev, NULL);
139	if (IS_ERR(clk)) {
140		dev_err(&pdev->dev, "no clock defined\n");
141		ret = -ENODEV;
142		goto exit;
143	}
144
145	/* get the platform data */
146	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
147	irq = platform_get_irq(pdev, 0);
148	if (!mem || irq <= 0) {
149		ret = -ENODEV;
150		goto exit_free_clk;
151	}
152
153	if (!request_mem_region(mem->start, resource_size(mem),
154				KBUILD_MODNAME)) {
155		dev_err(&pdev->dev, "resource unavailable\n");
156		ret = -ENODEV;
157		goto exit_free_clk;
158	}
159
160	addr = ioremap(mem->start, resource_size(mem));
161	if (!addr) {
162		dev_err(&pdev->dev, "failed to map can port\n");
163		ret = -ENOMEM;
164		goto exit_release_mem;
165	}
166
167	/* allocate the c_can device */
168	dev = alloc_c_can_dev();
169	if (!dev) {
170		ret = -ENOMEM;
171		goto exit_iounmap;
172	}
173
174	priv = netdev_priv(dev);
175	switch (id->driver_data) {
176	case BOSCH_C_CAN:
177		priv->regs = reg_map_c_can;
178		switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) {
179		case IORESOURCE_MEM_32BIT:
180			priv->read_reg = c_can_plat_read_reg_aligned_to_32bit;
181			priv->write_reg = c_can_plat_write_reg_aligned_to_32bit;
182			break;
183		case IORESOURCE_MEM_16BIT:
184		default:
185			priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
186			priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
187			break;
188		}
189		break;
190	case BOSCH_D_CAN:
191		priv->regs = reg_map_d_can;
192		priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
193		priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
194		priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
195
196		if (pdev->dev.of_node)
197			priv->instance = of_alias_get_id(pdev->dev.of_node, "d_can");
198		else
199			priv->instance = pdev->id;
200
201		res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
202		priv->raminit_ctrlreg =	devm_request_and_ioremap(&pdev->dev, res);
203		if (!priv->raminit_ctrlreg || priv->instance < 0)
204			dev_info(&pdev->dev, "control memory is not used for raminit\n");
205		else
206			priv->raminit = c_can_hw_raminit;
207		break;
208	default:
209		ret = -EINVAL;
210		goto exit_free_device;
211	}
212
213	dev->irq = irq;
214	priv->base = addr;
215	priv->device = &pdev->dev;
216	priv->can.clock.freq = clk_get_rate(clk);
217	priv->priv = clk;
218	priv->type = id->driver_data;
219
220	platform_set_drvdata(pdev, dev);
221	SET_NETDEV_DEV(dev, &pdev->dev);
222
223	ret = register_c_can_dev(dev);
224	if (ret) {
225		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
226			KBUILD_MODNAME, ret);
227		goto exit_free_device;
228	}
229
230	dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
231		 KBUILD_MODNAME, priv->base, dev->irq);
232	return 0;
233
234exit_free_device:
235	platform_set_drvdata(pdev, NULL);
236	free_c_can_dev(dev);
237exit_iounmap:
238	iounmap(addr);
239exit_release_mem:
240	release_mem_region(mem->start, resource_size(mem));
241exit_free_clk:
242	clk_put(clk);
243exit:
244	dev_err(&pdev->dev, "probe failed\n");
245
246	return ret;
247}
248
249static int __devexit c_can_plat_remove(struct platform_device *pdev)
250{
251	struct net_device *dev = platform_get_drvdata(pdev);
252	struct c_can_priv *priv = netdev_priv(dev);
253	struct resource *mem;
254
255	unregister_c_can_dev(dev);
256	platform_set_drvdata(pdev, NULL);
257
258	free_c_can_dev(dev);
259	iounmap(priv->base);
260
261	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
262	release_mem_region(mem->start, resource_size(mem));
263
264	clk_put(priv->priv);
265
266	return 0;
267}
268
269#ifdef CONFIG_PM
270static int c_can_suspend(struct platform_device *pdev, pm_message_t state)
271{
272	int ret;
273	struct net_device *ndev = platform_get_drvdata(pdev);
274	struct c_can_priv *priv = netdev_priv(ndev);
275
276	if (priv->type != BOSCH_D_CAN) {
277		dev_warn(&pdev->dev, "Not supported\n");
278		return 0;
279	}
280
281	if (netif_running(ndev)) {
282		netif_stop_queue(ndev);
283		netif_device_detach(ndev);
284	}
285
286	ret = c_can_power_down(ndev);
287	if (ret) {
288		netdev_err(ndev, "failed to enter power down mode\n");
289		return ret;
290	}
291
292	priv->can.state = CAN_STATE_SLEEPING;
293
294	return 0;
295}
296
297static int c_can_resume(struct platform_device *pdev)
298{
299	int ret;
300	struct net_device *ndev = platform_get_drvdata(pdev);
301	struct c_can_priv *priv = netdev_priv(ndev);
302
303	if (priv->type != BOSCH_D_CAN) {
304		dev_warn(&pdev->dev, "Not supported\n");
305		return 0;
306	}
307
308	ret = c_can_power_up(ndev);
309	if (ret) {
310		netdev_err(ndev, "Still in power down mode\n");
311		return ret;
312	}
313
314	priv->can.state = CAN_STATE_ERROR_ACTIVE;
315
316	if (netif_running(ndev)) {
317		netif_device_attach(ndev);
318		netif_start_queue(ndev);
319	}
320
321	return 0;
322}
323#else
324#define c_can_suspend NULL
325#define c_can_resume NULL
326#endif
327
328static struct platform_driver c_can_plat_driver = {
329	.driver = {
330		.name = KBUILD_MODNAME,
331		.owner = THIS_MODULE,
332		.of_match_table = of_match_ptr(c_can_of_table),
333	},
334	.probe = c_can_plat_probe,
335	.remove = __devexit_p(c_can_plat_remove),
336	.suspend = c_can_suspend,
337	.resume = c_can_resume,
338	.id_table = c_can_id_table,
339};
340
341module_platform_driver(c_can_plat_driver);
342
343MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>");
344MODULE_LICENSE("GPL v2");
345MODULE_DESCRIPTION("Platform CAN bus driver for Bosch C_CAN controller");
346