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_device.h>
31 #include <linux/of_irq.h>
32 
33 #include "sja1000.h"
34 
35 #define DRV_NAME "sja1000_platform"
36 #define SP_CAN_CLOCK  (16000000 / 2)
37 
38 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
39 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
40 MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the platform bus");
41 MODULE_ALIAS("platform:" DRV_NAME);
42 MODULE_LICENSE("GPL v2");
43 
44 struct sja1000_of_data {
45 	size_t  priv_sz;
46 	int     (*init)(struct sja1000_priv *priv, struct device_node *of);
47 };
48 
49 struct technologic_priv {
50 	spinlock_t      io_lock;
51 };
52 
53 static u8 sp_read_reg8(const struct sja1000_priv *priv, int reg)
54 {
55 	return ioread8(priv->reg_base + reg);
56 }
57 
58 static void sp_write_reg8(const struct sja1000_priv *priv, int reg, u8 val)
59 {
60 	iowrite8(val, priv->reg_base + reg);
61 }
62 
63 static u8 sp_read_reg16(const struct sja1000_priv *priv, int reg)
64 {
65 	return ioread8(priv->reg_base + reg * 2);
66 }
67 
68 static void sp_write_reg16(const struct sja1000_priv *priv, int reg, u8 val)
69 {
70 	iowrite8(val, priv->reg_base + reg * 2);
71 }
72 
73 static u8 sp_read_reg32(const struct sja1000_priv *priv, int reg)
74 {
75 	return ioread8(priv->reg_base + reg * 4);
76 }
77 
78 static void sp_write_reg32(const struct sja1000_priv *priv, int reg, u8 val)
79 {
80 	iowrite8(val, priv->reg_base + reg * 4);
81 }
82 
83 static u8 sp_technologic_read_reg16(const struct sja1000_priv *priv, int reg)
84 {
85 	struct technologic_priv *tp = priv->priv;
86 	unsigned long flags;
87 	u8 val;
88 
89 	spin_lock_irqsave(&tp->io_lock, flags);
90 	iowrite16(reg, priv->reg_base + 0);
91 	val = ioread16(priv->reg_base + 2);
92 	spin_unlock_irqrestore(&tp->io_lock, flags);
93 
94 	return val;
95 }
96 
97 static void sp_technologic_write_reg16(const struct sja1000_priv *priv,
98 				       int reg, u8 val)
99 {
100 	struct technologic_priv *tp = priv->priv;
101 	unsigned long flags;
102 
103 	spin_lock_irqsave(&tp->io_lock, flags);
104 	iowrite16(reg, priv->reg_base + 0);
105 	iowrite16(val, priv->reg_base + 2);
106 	spin_unlock_irqrestore(&tp->io_lock, flags);
107 }
108 
109 static int sp_technologic_init(struct sja1000_priv *priv, struct device_node *of)
110 {
111 	struct technologic_priv *tp = priv->priv;
112 
113 	priv->read_reg = sp_technologic_read_reg16;
114 	priv->write_reg = sp_technologic_write_reg16;
115 	spin_lock_init(&tp->io_lock);
116 
117 	return 0;
118 }
119 
120 static void sp_populate(struct sja1000_priv *priv,
121 			struct sja1000_platform_data *pdata,
122 			unsigned long resource_mem_flags)
123 {
124 	/* The CAN clock frequency is half the oscillator clock frequency */
125 	priv->can.clock.freq = pdata->osc_freq / 2;
126 	priv->ocr = pdata->ocr;
127 	priv->cdr = pdata->cdr;
128 
129 	switch (resource_mem_flags & IORESOURCE_MEM_TYPE_MASK) {
130 	case IORESOURCE_MEM_32BIT:
131 		priv->read_reg = sp_read_reg32;
132 		priv->write_reg = sp_write_reg32;
133 		break;
134 	case IORESOURCE_MEM_16BIT:
135 		priv->read_reg = sp_read_reg16;
136 		priv->write_reg = sp_write_reg16;
137 		break;
138 	case IORESOURCE_MEM_8BIT:
139 	default:
140 		priv->read_reg = sp_read_reg8;
141 		priv->write_reg = sp_write_reg8;
142 		break;
143 	}
144 }
145 
146 static void sp_populate_of(struct sja1000_priv *priv, struct device_node *of)
147 {
148 	int err;
149 	u32 prop;
150 
151 	err = of_property_read_u32(of, "reg-io-width", &prop);
152 	if (err)
153 		prop = 1; /* 8 bit is default */
154 
155 	switch (prop) {
156 	case 4:
157 		priv->read_reg = sp_read_reg32;
158 		priv->write_reg = sp_write_reg32;
159 		break;
160 	case 2:
161 		priv->read_reg = sp_read_reg16;
162 		priv->write_reg = sp_write_reg16;
163 		break;
164 	case 1:	/* fallthrough */
165 	default:
166 		priv->read_reg = sp_read_reg8;
167 		priv->write_reg = sp_write_reg8;
168 	}
169 
170 	err = of_property_read_u32(of, "nxp,external-clock-frequency", &prop);
171 	if (!err)
172 		priv->can.clock.freq = prop / 2;
173 	else
174 		priv->can.clock.freq = SP_CAN_CLOCK; /* default */
175 
176 	err = of_property_read_u32(of, "nxp,tx-output-mode", &prop);
177 	if (!err)
178 		priv->ocr |= prop & OCR_MODE_MASK;
179 	else
180 		priv->ocr |= OCR_MODE_NORMAL; /* default */
181 
182 	err = of_property_read_u32(of, "nxp,tx-output-config", &prop);
183 	if (!err)
184 		priv->ocr |= (prop << OCR_TX_SHIFT) & OCR_TX_MASK;
185 	else
186 		priv->ocr |= OCR_TX0_PULLDOWN; /* default */
187 
188 	err = of_property_read_u32(of, "nxp,clock-out-frequency", &prop);
189 	if (!err && prop) {
190 		u32 divider = priv->can.clock.freq * 2 / prop;
191 
192 		if (divider > 1)
193 			priv->cdr |= divider / 2 - 1;
194 		else
195 			priv->cdr |= CDR_CLKOUT_MASK;
196 	} else {
197 		priv->cdr |= CDR_CLK_OFF; /* default */
198 	}
199 
200 	if (!of_property_read_bool(of, "nxp,no-comparator-bypass"))
201 		priv->cdr |= CDR_CBP; /* default */
202 }
203 
204 static struct sja1000_of_data technologic_data = {
205 	.priv_sz = sizeof(struct technologic_priv),
206 	.init = sp_technologic_init,
207 };
208 
209 static const struct of_device_id sp_of_table[] = {
210 	{ .compatible = "nxp,sja1000", .data = NULL, },
211 	{ .compatible = "technologic,sja1000", .data = &technologic_data, },
212 	{ /* sentinel */ },
213 };
214 MODULE_DEVICE_TABLE(of, sp_of_table);
215 
216 static int sp_probe(struct platform_device *pdev)
217 {
218 	int err, irq = 0;
219 	void __iomem *addr;
220 	struct net_device *dev;
221 	struct sja1000_priv *priv;
222 	struct resource *res_mem, *res_irq = NULL;
223 	struct sja1000_platform_data *pdata;
224 	struct device_node *of = pdev->dev.of_node;
225 	const struct of_device_id *of_id;
226 	const struct sja1000_of_data *of_data = NULL;
227 	size_t priv_sz = 0;
228 
229 	pdata = dev_get_platdata(&pdev->dev);
230 	if (!pdata && !of) {
231 		dev_err(&pdev->dev, "No platform data provided!\n");
232 		return -ENODEV;
233 	}
234 
235 	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
236 	if (!res_mem)
237 		return -ENODEV;
238 
239 	if (!devm_request_mem_region(&pdev->dev, res_mem->start,
240 				     resource_size(res_mem), DRV_NAME))
241 		return -EBUSY;
242 
243 	addr = devm_ioremap_nocache(&pdev->dev, res_mem->start,
244 				    resource_size(res_mem));
245 	if (!addr)
246 		return -ENOMEM;
247 
248 	if (of)
249 		irq = irq_of_parse_and_map(of, 0);
250 	else
251 		res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
252 
253 	if (!irq && !res_irq)
254 		return -ENODEV;
255 
256 	of_id = of_match_device(sp_of_table, &pdev->dev);
257 	if (of_id && of_id->data) {
258 		of_data = of_id->data;
259 		priv_sz = of_data->priv_sz;
260 	}
261 
262 	dev = alloc_sja1000dev(priv_sz);
263 	if (!dev)
264 		return -ENOMEM;
265 	priv = netdev_priv(dev);
266 
267 	if (res_irq) {
268 		irq = res_irq->start;
269 		priv->irq_flags = res_irq->flags & IRQF_TRIGGER_MASK;
270 		if (res_irq->flags & IORESOURCE_IRQ_SHAREABLE)
271 			priv->irq_flags |= IRQF_SHARED;
272 	} else {
273 		priv->irq_flags = IRQF_SHARED;
274 	}
275 
276 	dev->irq = irq;
277 	priv->reg_base = addr;
278 
279 	if (of) {
280 		sp_populate_of(priv, of);
281 
282 		if (of_data && of_data->init) {
283 			err = of_data->init(priv, of);
284 			if (err)
285 				goto exit_free;
286 		}
287 	} else {
288 		sp_populate(priv, pdata, res_mem->flags);
289 	}
290 
291 	platform_set_drvdata(pdev, dev);
292 	SET_NETDEV_DEV(dev, &pdev->dev);
293 
294 	err = register_sja1000dev(dev);
295 	if (err) {
296 		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
297 			DRV_NAME, err);
298 		goto exit_free;
299 	}
300 
301 	dev_info(&pdev->dev, "%s device registered (reg_base=%p, irq=%d)\n",
302 		 DRV_NAME, priv->reg_base, dev->irq);
303 	return 0;
304 
305  exit_free:
306 	free_sja1000dev(dev);
307 	return err;
308 }
309 
310 static int sp_remove(struct platform_device *pdev)
311 {
312 	struct net_device *dev = platform_get_drvdata(pdev);
313 
314 	unregister_sja1000dev(dev);
315 	free_sja1000dev(dev);
316 
317 	return 0;
318 }
319 
320 static struct platform_driver sp_driver = {
321 	.probe = sp_probe,
322 	.remove = sp_remove,
323 	.driver = {
324 		.name = DRV_NAME,
325 		.of_match_table = sp_of_table,
326 	},
327 };
328 
329 module_platform_driver(sp_driver);
330