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/clk.h>
18#include <linux/io.h>
19#include <linux/of.h>
20
21#include "sja1000.h"
22
23#define DRV_NAME "sja1000_platform"
24#define SP_CAN_CLOCK  (16000000 / 2)
25
26MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
27MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
28MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the platform bus");
29MODULE_ALIAS("platform:" DRV_NAME);
30MODULE_LICENSE("GPL v2");
31
32struct sja1000_of_data {
33	size_t  priv_sz;
34	void    (*init)(struct sja1000_priv *priv, struct device_node *of);
35};
36
37struct technologic_priv {
38	spinlock_t      io_lock;
39};
40
41static u8 sp_read_reg8(const struct sja1000_priv *priv, int reg)
42{
43	return ioread8(priv->reg_base + reg);
44}
45
46static void sp_write_reg8(const struct sja1000_priv *priv, int reg, u8 val)
47{
48	iowrite8(val, priv->reg_base + reg);
49}
50
51static u8 sp_read_reg16(const struct sja1000_priv *priv, int reg)
52{
53	return ioread8(priv->reg_base + reg * 2);
54}
55
56static void sp_write_reg16(const struct sja1000_priv *priv, int reg, u8 val)
57{
58	iowrite8(val, priv->reg_base + reg * 2);
59}
60
61static u8 sp_read_reg32(const struct sja1000_priv *priv, int reg)
62{
63	return ioread8(priv->reg_base + reg * 4);
64}
65
66static void sp_write_reg32(const struct sja1000_priv *priv, int reg, u8 val)
67{
68	iowrite8(val, priv->reg_base + reg * 4);
69}
70
71static u8 sp_technologic_read_reg16(const struct sja1000_priv *priv, int reg)
72{
73	struct technologic_priv *tp = priv->priv;
74	unsigned long flags;
75	u8 val;
76
77	spin_lock_irqsave(&tp->io_lock, flags);
78	iowrite16(reg, priv->reg_base + 0);
79	val = ioread16(priv->reg_base + 2);
80	spin_unlock_irqrestore(&tp->io_lock, flags);
81
82	return val;
83}
84
85static void sp_technologic_write_reg16(const struct sja1000_priv *priv,
86				       int reg, u8 val)
87{
88	struct technologic_priv *tp = priv->priv;
89	unsigned long flags;
90
91	spin_lock_irqsave(&tp->io_lock, flags);
92	iowrite16(reg, priv->reg_base + 0);
93	iowrite16(val, priv->reg_base + 2);
94	spin_unlock_irqrestore(&tp->io_lock, flags);
95}
96
97static void sp_technologic_init(struct sja1000_priv *priv, struct device_node *of)
98{
99	struct technologic_priv *tp = priv->priv;
100
101	priv->read_reg = sp_technologic_read_reg16;
102	priv->write_reg = sp_technologic_write_reg16;
103	spin_lock_init(&tp->io_lock);
104}
105
106static void sp_rzn1_init(struct sja1000_priv *priv, struct device_node *of)
107{
108	priv->flags = SJA1000_QUIRK_NO_CDR_REG | SJA1000_QUIRK_RESET_ON_OVERRUN;
109}
110
111static void sp_populate(struct sja1000_priv *priv,
112			struct sja1000_platform_data *pdata,
113			unsigned long resource_mem_flags)
114{
115	/* The CAN clock frequency is half the oscillator clock frequency */
116	priv->can.clock.freq = pdata->osc_freq / 2;
117	priv->ocr = pdata->ocr;
118	priv->cdr = pdata->cdr;
119
120	switch (resource_mem_flags & IORESOURCE_MEM_TYPE_MASK) {
121	case IORESOURCE_MEM_32BIT:
122		priv->read_reg = sp_read_reg32;
123		priv->write_reg = sp_write_reg32;
124		break;
125	case IORESOURCE_MEM_16BIT:
126		priv->read_reg = sp_read_reg16;
127		priv->write_reg = sp_write_reg16;
128		break;
129	case IORESOURCE_MEM_8BIT:
130	default:
131		priv->read_reg = sp_read_reg8;
132		priv->write_reg = sp_write_reg8;
133		break;
134	}
135}
136
137static void sp_populate_of(struct sja1000_priv *priv, struct device_node *of)
138{
139	int err;
140	u32 prop;
141
142	err = of_property_read_u32(of, "reg-io-width", &prop);
143	if (err)
144		prop = 1; /* 8 bit is default */
145
146	switch (prop) {
147	case 4:
148		priv->read_reg = sp_read_reg32;
149		priv->write_reg = sp_write_reg32;
150		break;
151	case 2:
152		priv->read_reg = sp_read_reg16;
153		priv->write_reg = sp_write_reg16;
154		break;
155	case 1:
156	default:
157		priv->read_reg = sp_read_reg8;
158		priv->write_reg = sp_write_reg8;
159	}
160
161	if (!priv->can.clock.freq) {
162		err = of_property_read_u32(of, "nxp,external-clock-frequency", &prop);
163		if (!err)
164			priv->can.clock.freq = prop / 2;
165		else
166			priv->can.clock.freq = SP_CAN_CLOCK; /* default */
167	}
168
169	err = of_property_read_u32(of, "nxp,tx-output-mode", &prop);
170	if (!err)
171		priv->ocr |= prop & OCR_MODE_MASK;
172	else
173		priv->ocr |= OCR_MODE_NORMAL; /* default */
174
175	err = of_property_read_u32(of, "nxp,tx-output-config", &prop);
176	if (!err)
177		priv->ocr |= (prop << OCR_TX_SHIFT) & OCR_TX_MASK;
178	else
179		priv->ocr |= OCR_TX0_PULLDOWN; /* default */
180
181	err = of_property_read_u32(of, "nxp,clock-out-frequency", &prop);
182	if (!err && prop) {
183		u32 divider = priv->can.clock.freq * 2 / prop;
184
185		if (divider > 1)
186			priv->cdr |= divider / 2 - 1;
187		else
188			priv->cdr |= CDR_CLKOUT_MASK;
189	} else {
190		priv->cdr |= CDR_CLK_OFF; /* default */
191	}
192
193	if (!of_property_read_bool(of, "nxp,no-comparator-bypass"))
194		priv->cdr |= CDR_CBP; /* default */
195}
196
197static struct sja1000_of_data technologic_data = {
198	.priv_sz = sizeof(struct technologic_priv),
199	.init = sp_technologic_init,
200};
201
202static struct sja1000_of_data renesas_data = {
203	.init = sp_rzn1_init,
204};
205
206static const struct of_device_id sp_of_table[] = {
207	{ .compatible = "nxp,sja1000", .data = NULL, },
208	{ .compatible = "renesas,rzn1-sja1000", .data = &renesas_data, },
209	{ .compatible = "technologic,sja1000", .data = &technologic_data, },
210	{ /* sentinel */ },
211};
212MODULE_DEVICE_TABLE(of, sp_of_table);
213
214static int sp_probe(struct platform_device *pdev)
215{
216	int err, irq = 0;
217	void __iomem *addr;
218	struct net_device *dev;
219	struct sja1000_priv *priv;
220	struct resource *res_mem, *res_irq = NULL;
221	struct sja1000_platform_data *pdata;
222	struct device_node *of = pdev->dev.of_node;
223	const struct sja1000_of_data *of_data = NULL;
224	size_t priv_sz = 0;
225	struct clk *clk;
226
227	pdata = dev_get_platdata(&pdev->dev);
228	if (!pdata && !of) {
229		dev_err(&pdev->dev, "No platform data provided!\n");
230		return -ENODEV;
231	}
232
233	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
234	if (!res_mem)
235		return -ENODEV;
236
237	if (!devm_request_mem_region(&pdev->dev, res_mem->start,
238				     resource_size(res_mem), DRV_NAME))
239		return -EBUSY;
240
241	addr = devm_ioremap(&pdev->dev, res_mem->start,
242				    resource_size(res_mem));
243	if (!addr)
244		return -ENOMEM;
245
246	if (of) {
247		irq = platform_get_irq(pdev, 0);
248		if (irq < 0)
249			return irq;
250
251		clk = devm_clk_get_optional_enabled(&pdev->dev, NULL);
252		if (IS_ERR(clk))
253			return dev_err_probe(&pdev->dev, PTR_ERR(clk),
254					     "CAN clk operation failed");
255	} else {
256		res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
257		if (!res_irq)
258			return -ENODEV;
259	}
260
261	of_data = device_get_match_data(&pdev->dev);
262	if (of_data)
263		priv_sz = of_data->priv_sz;
264
265	dev = alloc_sja1000dev(priv_sz);
266	if (!dev)
267		return -ENOMEM;
268	priv = netdev_priv(dev);
269
270	if (res_irq) {
271		irq = res_irq->start;
272		priv->irq_flags = res_irq->flags & IRQF_TRIGGER_MASK;
273		if (res_irq->flags & IORESOURCE_IRQ_SHAREABLE)
274			priv->irq_flags |= IRQF_SHARED;
275	} else {
276		priv->irq_flags = IRQF_SHARED;
277	}
278
279	if (priv->flags & SJA1000_QUIRK_RESET_ON_OVERRUN)
280		priv->irq_flags |= IRQF_ONESHOT;
281
282	dev->irq = irq;
283	priv->reg_base = addr;
284
285	if (of) {
286		if (clk) {
287			priv->can.clock.freq  = clk_get_rate(clk) / 2;
288			if (!priv->can.clock.freq) {
289				err = -EINVAL;
290				dev_err(&pdev->dev, "Zero CAN clk rate");
291				goto exit_free;
292			}
293		}
294
295		sp_populate_of(priv, of);
296
297		if (of_data && of_data->init)
298			of_data->init(priv, of);
299	} else {
300		sp_populate(priv, pdata, res_mem->flags);
301	}
302
303	platform_set_drvdata(pdev, dev);
304	SET_NETDEV_DEV(dev, &pdev->dev);
305
306	err = register_sja1000dev(dev);
307	if (err) {
308		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
309			DRV_NAME, err);
310		goto exit_free;
311	}
312
313	dev_info(&pdev->dev, "%s device registered (reg_base=%p, irq=%d)\n",
314		 DRV_NAME, priv->reg_base, dev->irq);
315	return 0;
316
317 exit_free:
318	free_sja1000dev(dev);
319	return err;
320}
321
322static void sp_remove(struct platform_device *pdev)
323{
324	struct net_device *dev = platform_get_drvdata(pdev);
325
326	unregister_sja1000dev(dev);
327	free_sja1000dev(dev);
328}
329
330static struct platform_driver sp_driver = {
331	.probe = sp_probe,
332	.remove_new = sp_remove,
333	.driver = {
334		.name = DRV_NAME,
335		.of_match_table = sp_of_table,
336	},
337};
338
339module_platform_driver(sp_driver);
340