c_can_platform.c revision 5e946e56231b5c765598cd3103faf3c7a0121812 
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};
100MODULE_DEVICE_TABLE(platform, c_can_id_table);
101
102static const struct of_device_id c_can_of_table[] = {
103	{ .compatible = "bosch,c_can", .data = &c_can_id_table[BOSCH_C_CAN] },
104	{ .compatible = "bosch,d_can", .data = &c_can_id_table[BOSCH_D_CAN] },
105	{ /* sentinel */ },
106};
107MODULE_DEVICE_TABLE(of, c_can_of_table);
108
109static int c_can_plat_probe(struct platform_device *pdev)
110{
111	int ret;
112	void __iomem *addr;
113	struct net_device *dev;
114	struct c_can_priv *priv;
115	const struct of_device_id *match;
116	const struct platform_device_id *id;
117	struct pinctrl *pinctrl;
118	struct resource *mem, *res;
119	int irq;
120	struct clk *clk;
121
122	if (pdev->dev.of_node) {
123		match = of_match_device(c_can_of_table, &pdev->dev);
124		if (!match) {
125			dev_err(&pdev->dev, "Failed to find matching dt id\n");
126			ret = -EINVAL;
127			goto exit;
128		}
129		id = match->data;
130	} else {
131		id = platform_get_device_id(pdev);
132	}
133
134	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
135	if (IS_ERR(pinctrl))
136		dev_warn(&pdev->dev,
137			"failed to configure pins from driver\n");
138
139	/* get the appropriate clk */
140	clk = clk_get(&pdev->dev, NULL);
141	if (IS_ERR(clk)) {
142		dev_err(&pdev->dev, "no clock defined\n");
143		ret = -ENODEV;
144		goto exit;
145	}
146
147	/* get the platform data */
148	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
149	irq = platform_get_irq(pdev, 0);
150	if (!mem || irq <= 0) {
151		ret = -ENODEV;
152		goto exit_free_clk;
153	}
154
155	if (!request_mem_region(mem->start, resource_size(mem),
156				KBUILD_MODNAME)) {
157		dev_err(&pdev->dev, "resource unavailable\n");
158		ret = -ENODEV;
159		goto exit_free_clk;
160	}
161
162	addr = ioremap(mem->start, resource_size(mem));
163	if (!addr) {
164		dev_err(&pdev->dev, "failed to map can port\n");
165		ret = -ENOMEM;
166		goto exit_release_mem;
167	}
168
169	/* allocate the c_can device */
170	dev = alloc_c_can_dev();
171	if (!dev) {
172		ret = -ENOMEM;
173		goto exit_iounmap;
174	}
175
176	priv = netdev_priv(dev);
177	switch (id->driver_data) {
178	case BOSCH_C_CAN:
179		priv->regs = reg_map_c_can;
180		switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) {
181		case IORESOURCE_MEM_32BIT:
182			priv->read_reg = c_can_plat_read_reg_aligned_to_32bit;
183			priv->write_reg = c_can_plat_write_reg_aligned_to_32bit;
184			break;
185		case IORESOURCE_MEM_16BIT:
186		default:
187			priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
188			priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
189			break;
190		}
191		break;
192	case BOSCH_D_CAN:
193		priv->regs = reg_map_d_can;
194		priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
195		priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
196		priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
197
198		if (pdev->dev.of_node)
199			priv->instance = of_alias_get_id(pdev->dev.of_node, "d_can");
200		else
201			priv->instance = pdev->id;
202
203		res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
204		priv->raminit_ctrlreg =	devm_request_and_ioremap(&pdev->dev, res);
205		if (!priv->raminit_ctrlreg || priv->instance < 0)
206			dev_info(&pdev->dev, "control memory is not used for raminit\n");
207		else
208			priv->raminit = c_can_hw_raminit;
209		break;
210	default:
211		ret = -EINVAL;
212		goto exit_free_device;
213	}
214
215	dev->irq = irq;
216	priv->base = addr;
217	priv->device = &pdev->dev;
218	priv->can.clock.freq = clk_get_rate(clk);
219	priv->priv = clk;
220	priv->type = id->driver_data;
221
222	platform_set_drvdata(pdev, dev);
223	SET_NETDEV_DEV(dev, &pdev->dev);
224
225	ret = register_c_can_dev(dev);
226	if (ret) {
227		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
228			KBUILD_MODNAME, ret);
229		goto exit_free_device;
230	}
231
232	dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
233		 KBUILD_MODNAME, priv->base, dev->irq);
234	return 0;
235
236exit_free_device:
237	free_c_can_dev(dev);
238exit_iounmap:
239	iounmap(addr);
240exit_release_mem:
241	release_mem_region(mem->start, resource_size(mem));
242exit_free_clk:
243	clk_put(clk);
244exit:
245	dev_err(&pdev->dev, "probe failed\n");
246
247	return ret;
248}
249
250static int c_can_plat_remove(struct platform_device *pdev)
251{
252	struct net_device *dev = platform_get_drvdata(pdev);
253	struct c_can_priv *priv = netdev_priv(dev);
254	struct resource *mem;
255
256	unregister_c_can_dev(dev);
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 = 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