1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2005 Sascha Hauer, Pengutronix
4  * Copyright (C) 2007 Wolfgang Grandegger <wg@grandegger.com>
5  */
6 
7 #include <linux/kernel.h>
8 #include <linux/module.h>
9 #include <linux/interrupt.h>
10 #include <linux/netdevice.h>
11 #include <linux/delay.h>
12 #include <linux/pci.h>
13 #include <linux/platform_device.h>
14 #include <linux/irq.h>
15 #include <linux/can/dev.h>
16 #include <linux/can/platform/sja1000.h>
17 #include <linux/io.h>
18 #include <linux/of.h>
19 #include <linux/of_device.h>
20 #include <linux/of_irq.h>
21 
22 #include "sja1000.h"
23 
24 #define DRV_NAME "sja1000_platform"
25 #define SP_CAN_CLOCK  (16000000 / 2)
26 
27 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
28 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
29 MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the platform bus");
30 MODULE_ALIAS("platform:" DRV_NAME);
31 MODULE_LICENSE("GPL v2");
32 
33 struct sja1000_of_data {
34 	size_t  priv_sz;
35 	int     (*init)(struct sja1000_priv *priv, struct device_node *of);
36 };
37 
38 struct technologic_priv {
39 	spinlock_t      io_lock;
40 };
41 
42 static u8 sp_read_reg8(const struct sja1000_priv *priv, int reg)
43 {
44 	return ioread8(priv->reg_base + reg);
45 }
46 
47 static void sp_write_reg8(const struct sja1000_priv *priv, int reg, u8 val)
48 {
49 	iowrite8(val, priv->reg_base + reg);
50 }
51 
52 static u8 sp_read_reg16(const struct sja1000_priv *priv, int reg)
53 {
54 	return ioread8(priv->reg_base + reg * 2);
55 }
56 
57 static void sp_write_reg16(const struct sja1000_priv *priv, int reg, u8 val)
58 {
59 	iowrite8(val, priv->reg_base + reg * 2);
60 }
61 
62 static u8 sp_read_reg32(const struct sja1000_priv *priv, int reg)
63 {
64 	return ioread8(priv->reg_base + reg * 4);
65 }
66 
67 static void sp_write_reg32(const struct sja1000_priv *priv, int reg, u8 val)
68 {
69 	iowrite8(val, priv->reg_base + reg * 4);
70 }
71 
72 static u8 sp_technologic_read_reg16(const struct sja1000_priv *priv, int reg)
73 {
74 	struct technologic_priv *tp = priv->priv;
75 	unsigned long flags;
76 	u8 val;
77 
78 	spin_lock_irqsave(&tp->io_lock, flags);
79 	iowrite16(reg, priv->reg_base + 0);
80 	val = ioread16(priv->reg_base + 2);
81 	spin_unlock_irqrestore(&tp->io_lock, flags);
82 
83 	return val;
84 }
85 
86 static void sp_technologic_write_reg16(const struct sja1000_priv *priv,
87 				       int reg, u8 val)
88 {
89 	struct technologic_priv *tp = priv->priv;
90 	unsigned long flags;
91 
92 	spin_lock_irqsave(&tp->io_lock, flags);
93 	iowrite16(reg, priv->reg_base + 0);
94 	iowrite16(val, priv->reg_base + 2);
95 	spin_unlock_irqrestore(&tp->io_lock, flags);
96 }
97 
98 static int sp_technologic_init(struct sja1000_priv *priv, struct device_node *of)
99 {
100 	struct technologic_priv *tp = priv->priv;
101 
102 	priv->read_reg = sp_technologic_read_reg16;
103 	priv->write_reg = sp_technologic_write_reg16;
104 	spin_lock_init(&tp->io_lock);
105 
106 	return 0;
107 }
108 
109 static void sp_populate(struct sja1000_priv *priv,
110 			struct sja1000_platform_data *pdata,
111 			unsigned long resource_mem_flags)
112 {
113 	/* The CAN clock frequency is half the oscillator clock frequency */
114 	priv->can.clock.freq = pdata->osc_freq / 2;
115 	priv->ocr = pdata->ocr;
116 	priv->cdr = pdata->cdr;
117 
118 	switch (resource_mem_flags & IORESOURCE_MEM_TYPE_MASK) {
119 	case IORESOURCE_MEM_32BIT:
120 		priv->read_reg = sp_read_reg32;
121 		priv->write_reg = sp_write_reg32;
122 		break;
123 	case IORESOURCE_MEM_16BIT:
124 		priv->read_reg = sp_read_reg16;
125 		priv->write_reg = sp_write_reg16;
126 		break;
127 	case IORESOURCE_MEM_8BIT:
128 	default:
129 		priv->read_reg = sp_read_reg8;
130 		priv->write_reg = sp_write_reg8;
131 		break;
132 	}
133 }
134 
135 static void sp_populate_of(struct sja1000_priv *priv, struct device_node *of)
136 {
137 	int err;
138 	u32 prop;
139 
140 	err = of_property_read_u32(of, "reg-io-width", &prop);
141 	if (err)
142 		prop = 1; /* 8 bit is default */
143 
144 	switch (prop) {
145 	case 4:
146 		priv->read_reg = sp_read_reg32;
147 		priv->write_reg = sp_write_reg32;
148 		break;
149 	case 2:
150 		priv->read_reg = sp_read_reg16;
151 		priv->write_reg = sp_write_reg16;
152 		break;
153 	case 1:	/* fallthrough */
154 	default:
155 		priv->read_reg = sp_read_reg8;
156 		priv->write_reg = sp_write_reg8;
157 	}
158 
159 	err = of_property_read_u32(of, "nxp,external-clock-frequency", &prop);
160 	if (!err)
161 		priv->can.clock.freq = prop / 2;
162 	else
163 		priv->can.clock.freq = SP_CAN_CLOCK; /* default */
164 
165 	err = of_property_read_u32(of, "nxp,tx-output-mode", &prop);
166 	if (!err)
167 		priv->ocr |= prop & OCR_MODE_MASK;
168 	else
169 		priv->ocr |= OCR_MODE_NORMAL; /* default */
170 
171 	err = of_property_read_u32(of, "nxp,tx-output-config", &prop);
172 	if (!err)
173 		priv->ocr |= (prop << OCR_TX_SHIFT) & OCR_TX_MASK;
174 	else
175 		priv->ocr |= OCR_TX0_PULLDOWN; /* default */
176 
177 	err = of_property_read_u32(of, "nxp,clock-out-frequency", &prop);
178 	if (!err && prop) {
179 		u32 divider = priv->can.clock.freq * 2 / prop;
180 
181 		if (divider > 1)
182 			priv->cdr |= divider / 2 - 1;
183 		else
184 			priv->cdr |= CDR_CLKOUT_MASK;
185 	} else {
186 		priv->cdr |= CDR_CLK_OFF; /* default */
187 	}
188 
189 	if (!of_property_read_bool(of, "nxp,no-comparator-bypass"))
190 		priv->cdr |= CDR_CBP; /* default */
191 }
192 
193 static struct sja1000_of_data technologic_data = {
194 	.priv_sz = sizeof(struct technologic_priv),
195 	.init = sp_technologic_init,
196 };
197 
198 static const struct of_device_id sp_of_table[] = {
199 	{ .compatible = "nxp,sja1000", .data = NULL, },
200 	{ .compatible = "technologic,sja1000", .data = &technologic_data, },
201 	{ /* sentinel */ },
202 };
203 MODULE_DEVICE_TABLE(of, sp_of_table);
204 
205 static int sp_probe(struct platform_device *pdev)
206 {
207 	int err, irq = 0;
208 	void __iomem *addr;
209 	struct net_device *dev;
210 	struct sja1000_priv *priv;
211 	struct resource *res_mem, *res_irq = NULL;
212 	struct sja1000_platform_data *pdata;
213 	struct device_node *of = pdev->dev.of_node;
214 	const struct of_device_id *of_id;
215 	const struct sja1000_of_data *of_data = NULL;
216 	size_t priv_sz = 0;
217 
218 	pdata = dev_get_platdata(&pdev->dev);
219 	if (!pdata && !of) {
220 		dev_err(&pdev->dev, "No platform data provided!\n");
221 		return -ENODEV;
222 	}
223 
224 	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
225 	if (!res_mem)
226 		return -ENODEV;
227 
228 	if (!devm_request_mem_region(&pdev->dev, res_mem->start,
229 				     resource_size(res_mem), DRV_NAME))
230 		return -EBUSY;
231 
232 	addr = devm_ioremap(&pdev->dev, res_mem->start,
233 				    resource_size(res_mem));
234 	if (!addr)
235 		return -ENOMEM;
236 
237 	if (of)
238 		irq = irq_of_parse_and_map(of, 0);
239 	else
240 		res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
241 
242 	if (!irq && !res_irq)
243 		return -ENODEV;
244 
245 	of_id = of_match_device(sp_of_table, &pdev->dev);
246 	if (of_id && of_id->data) {
247 		of_data = of_id->data;
248 		priv_sz = of_data->priv_sz;
249 	}
250 
251 	dev = alloc_sja1000dev(priv_sz);
252 	if (!dev)
253 		return -ENOMEM;
254 	priv = netdev_priv(dev);
255 
256 	if (res_irq) {
257 		irq = res_irq->start;
258 		priv->irq_flags = res_irq->flags & IRQF_TRIGGER_MASK;
259 		if (res_irq->flags & IORESOURCE_IRQ_SHAREABLE)
260 			priv->irq_flags |= IRQF_SHARED;
261 	} else {
262 		priv->irq_flags = IRQF_SHARED;
263 	}
264 
265 	dev->irq = irq;
266 	priv->reg_base = addr;
267 
268 	if (of) {
269 		sp_populate_of(priv, of);
270 
271 		if (of_data && of_data->init) {
272 			err = of_data->init(priv, of);
273 			if (err)
274 				goto exit_free;
275 		}
276 	} else {
277 		sp_populate(priv, pdata, res_mem->flags);
278 	}
279 
280 	platform_set_drvdata(pdev, dev);
281 	SET_NETDEV_DEV(dev, &pdev->dev);
282 
283 	err = register_sja1000dev(dev);
284 	if (err) {
285 		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
286 			DRV_NAME, err);
287 		goto exit_free;
288 	}
289 
290 	dev_info(&pdev->dev, "%s device registered (reg_base=%p, irq=%d)\n",
291 		 DRV_NAME, priv->reg_base, dev->irq);
292 	return 0;
293 
294  exit_free:
295 	free_sja1000dev(dev);
296 	return err;
297 }
298 
299 static int sp_remove(struct platform_device *pdev)
300 {
301 	struct net_device *dev = platform_get_drvdata(pdev);
302 
303 	unregister_sja1000dev(dev);
304 	free_sja1000dev(dev);
305 
306 	return 0;
307 }
308 
309 static struct platform_driver sp_driver = {
310 	.probe = sp_probe,
311 	.remove = sp_remove,
312 	.driver = {
313 		.name = DRV_NAME,
314 		.of_match_table = sp_of_table,
315 	},
316 };
317 
318 module_platform_driver(sp_driver);
319