sja1000_platform.c revision 02729c3d08c9334d03d61d365ff2408514a46c81 
1/*
2 * Copyright (C) 2005 Sascha Hauer, Pengutronix
3 * Copyright (C) 2007 Wolfgang Grandegger <wg@grandegger.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the version 2 of the GNU General Public License
7 * as published by the Free Software Foundation
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, see <http://www.gnu.org/licenses/>.
16 */
17
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/interrupt.h>
21#include <linux/netdevice.h>
22#include <linux/delay.h>
23#include <linux/pci.h>
24#include <linux/platform_device.h>
25#include <linux/irq.h>
26#include <linux/can/dev.h>
27#include <linux/can/platform/sja1000.h>
28#include <linux/io.h>
29#include <linux/of.h>
30#include <linux/of_irq.h>
31
32#include "sja1000.h"
33
34#define DRV_NAME "sja1000_platform"
35#define SP_CAN_CLOCK  (16000000 / 2)
36
37MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
38MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
39MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the platform bus");
40MODULE_ALIAS("platform:" DRV_NAME);
41MODULE_LICENSE("GPL v2");
42
43static u8 sp_read_reg8(const struct sja1000_priv *priv, int reg)
44{
45	return ioread8(priv->reg_base + reg);
46}
47
48static void sp_write_reg8(const struct sja1000_priv *priv, int reg, u8 val)
49{
50	iowrite8(val, priv->reg_base + reg);
51}
52
53static u8 sp_read_reg16(const struct sja1000_priv *priv, int reg)
54{
55	return ioread8(priv->reg_base + reg * 2);
56}
57
58static void sp_write_reg16(const struct sja1000_priv *priv, int reg, u8 val)
59{
60	iowrite8(val, priv->reg_base + reg * 2);
61}
62
63static u8 sp_read_reg32(const struct sja1000_priv *priv, int reg)
64{
65	return ioread8(priv->reg_base + reg * 4);
66}
67
68static void sp_write_reg32(const struct sja1000_priv *priv, int reg, u8 val)
69{
70	iowrite8(val, priv->reg_base + reg * 4);
71}
72
73static void sp_populate(struct sja1000_priv *priv,
74			struct sja1000_platform_data *pdata,
75			unsigned long resource_mem_flags)
76{
77	/* The CAN clock frequency is half the oscillator clock frequency */
78	priv->can.clock.freq = pdata->osc_freq / 2;
79	priv->ocr = pdata->ocr;
80	priv->cdr = pdata->cdr;
81
82	switch (resource_mem_flags & IORESOURCE_MEM_TYPE_MASK) {
83	case IORESOURCE_MEM_32BIT:
84		priv->read_reg = sp_read_reg32;
85		priv->write_reg = sp_write_reg32;
86		break;
87	case IORESOURCE_MEM_16BIT:
88		priv->read_reg = sp_read_reg16;
89		priv->write_reg = sp_write_reg16;
90		break;
91	case IORESOURCE_MEM_8BIT:
92	default:
93		priv->read_reg = sp_read_reg8;
94		priv->write_reg = sp_write_reg8;
95		break;
96	}
97}
98
99static void sp_populate_of(struct sja1000_priv *priv, struct device_node *of)
100{
101	int err;
102	u32 prop;
103
104	priv->read_reg = sp_read_reg8;
105	priv->write_reg = sp_write_reg8;
106
107	err = of_property_read_u32(of, "nxp,external-clock-frequency", &prop);
108	if (!err)
109		priv->can.clock.freq = prop / 2;
110	else
111		priv->can.clock.freq = SP_CAN_CLOCK; /* default */
112
113	err = of_property_read_u32(of, "nxp,tx-output-mode", &prop);
114	if (!err)
115		priv->ocr |= prop & OCR_MODE_MASK;
116	else
117		priv->ocr |= OCR_MODE_NORMAL; /* default */
118
119	err = of_property_read_u32(of, "nxp,tx-output-config", &prop);
120	if (!err)
121		priv->ocr |= (prop << OCR_TX_SHIFT) & OCR_TX_MASK;
122	else
123		priv->ocr |= OCR_TX0_PULLDOWN; /* default */
124
125	err = of_property_read_u32(of, "nxp,clock-out-frequency", &prop);
126	if (!err && prop) {
127		u32 divider = priv->can.clock.freq * 2 / prop;
128
129		if (divider > 1)
130			priv->cdr |= divider / 2 - 1;
131		else
132			priv->cdr |= CDR_CLKOUT_MASK;
133	} else {
134		priv->cdr |= CDR_CLK_OFF; /* default */
135	}
136
137	if (!of_property_read_bool(of, "nxp,no-comparator-bypass"))
138		priv->cdr |= CDR_CBP; /* default */
139}
140
141static int sp_probe(struct platform_device *pdev)
142{
143	int err, irq = 0;
144	void __iomem *addr;
145	struct net_device *dev;
146	struct sja1000_priv *priv;
147	struct resource *res_mem, *res_irq = NULL;
148	struct sja1000_platform_data *pdata;
149	struct device_node *of = pdev->dev.of_node;
150
151	pdata = dev_get_platdata(&pdev->dev);
152	if (!pdata && !of) {
153		dev_err(&pdev->dev, "No platform data provided!\n");
154		return -ENODEV;
155	}
156
157	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
158	if (!res_mem)
159		return -ENODEV;
160
161	if (!devm_request_mem_region(&pdev->dev, res_mem->start,
162				     resource_size(res_mem), DRV_NAME))
163		return -EBUSY;
164
165	addr = devm_ioremap_nocache(&pdev->dev, res_mem->start,
166				    resource_size(res_mem));
167	if (!addr)
168		return -ENOMEM;
169
170	if (of)
171		irq = irq_of_parse_and_map(of, 0);
172	else
173		res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
174
175	if (!irq && !res_irq)
176		return -ENODEV;
177
178	dev = alloc_sja1000dev(0);
179	if (!dev)
180		return -ENOMEM;
181	priv = netdev_priv(dev);
182
183	if (res_irq) {
184		irq = res_irq->start;
185		priv->irq_flags = res_irq->flags & IRQF_TRIGGER_MASK;
186		if (res_irq->flags & IORESOURCE_IRQ_SHAREABLE)
187			priv->irq_flags |= IRQF_SHARED;
188	} else {
189		priv->irq_flags = IRQF_SHARED;
190	}
191
192	dev->irq = irq;
193	priv->reg_base = addr;
194
195	if (of)
196		sp_populate_of(priv, of);
197	else
198		sp_populate(priv, pdata, res_mem->flags);
199
200	platform_set_drvdata(pdev, dev);
201	SET_NETDEV_DEV(dev, &pdev->dev);
202
203	err = register_sja1000dev(dev);
204	if (err) {
205		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
206			DRV_NAME, err);
207		goto exit_free;
208	}
209
210	dev_info(&pdev->dev, "%s device registered (reg_base=%p, irq=%d)\n",
211		 DRV_NAME, priv->reg_base, dev->irq);
212	return 0;
213
214 exit_free:
215	free_sja1000dev(dev);
216	return err;
217}
218
219static int sp_remove(struct platform_device *pdev)
220{
221	struct net_device *dev = platform_get_drvdata(pdev);
222
223	unregister_sja1000dev(dev);
224	free_sja1000dev(dev);
225
226	return 0;
227}
228
229static struct of_device_id sp_of_table[] = {
230	{.compatible = "nxp,sja1000"},
231	{},
232};
233MODULE_DEVICE_TABLE(of, sp_of_table);
234
235static struct platform_driver sp_driver = {
236	.probe = sp_probe,
237	.remove = sp_remove,
238	.driver = {
239		.name = DRV_NAME,
240		.owner = THIS_MODULE,
241		.of_match_table = sp_of_table,
242	},
243};
244
245module_platform_driver(sp_driver);
246