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
27MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
28MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
29MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the platform bus");
30MODULE_ALIAS("platform:" DRV_NAME);
31MODULE_LICENSE("GPL v2");
32
33struct sja1000_of_data {
34	size_t  priv_sz;
35	int     (*init)(struct sja1000_priv *priv, struct device_node *of);
36};
37
38struct technologic_priv {
39	spinlock_t      io_lock;
40};
41
42static u8 sp_read_reg8(const struct sja1000_priv *priv, int reg)
43{
44	return ioread8(priv->reg_base + reg);
45}
46
47static void sp_write_reg8(const struct sja1000_priv *priv, int reg, u8 val)
48{
49	iowrite8(val, priv->reg_base + reg);
50}
51
52static u8 sp_read_reg16(const struct sja1000_priv *priv, int reg)
53{
54	return ioread8(priv->reg_base + reg * 2);
55}
56
57static void sp_write_reg16(const struct sja1000_priv *priv, int reg, u8 val)
58{
59	iowrite8(val, priv->reg_base + reg * 2);
60}
61
62static u8 sp_read_reg32(const struct sja1000_priv *priv, int reg)
63{
64	return ioread8(priv->reg_base + reg * 4);
65}
66
67static void sp_write_reg32(const struct sja1000_priv *priv, int reg, u8 val)
68{
69	iowrite8(val, priv->reg_base + reg * 4);
70}
71
72static 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
86static 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
98static 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
109static 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
135static 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:
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
193static struct sja1000_of_data technologic_data = {
194	.priv_sz = sizeof(struct technologic_priv),
195	.init = sp_technologic_init,
196};
197
198static const struct of_device_id sp_of_table[] = {
199	{ .compatible = "nxp,sja1000", .data = NULL, },
200	{ .compatible = "technologic,sja1000", .data = &technologic_data, },
201	{ /* sentinel */ },
202};
203MODULE_DEVICE_TABLE(of, sp_of_table);
204
205static 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
299static 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
309static 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
318module_platform_driver(sp_driver);
319