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
sp_read_reg8(const struct sja1000_priv * priv,int reg)42 static u8 sp_read_reg8(const struct sja1000_priv *priv, int reg)
43 {
44 return ioread8(priv->reg_base + reg);
45 }
46
sp_write_reg8(const struct sja1000_priv * priv,int reg,u8 val)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
sp_read_reg16(const struct sja1000_priv * priv,int reg)52 static u8 sp_read_reg16(const struct sja1000_priv *priv, int reg)
53 {
54 return ioread8(priv->reg_base + reg * 2);
55 }
56
sp_write_reg16(const struct sja1000_priv * priv,int reg,u8 val)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
sp_read_reg32(const struct sja1000_priv * priv,int reg)62 static u8 sp_read_reg32(const struct sja1000_priv *priv, int reg)
63 {
64 return ioread8(priv->reg_base + reg * 4);
65 }
66
sp_write_reg32(const struct sja1000_priv * priv,int reg,u8 val)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
sp_technologic_read_reg16(const struct sja1000_priv * priv,int reg)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
sp_technologic_write_reg16(const struct sja1000_priv * priv,int reg,u8 val)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
sp_technologic_init(struct sja1000_priv * priv,struct device_node * of)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
sp_populate(struct sja1000_priv * priv,struct sja1000_platform_data * pdata,unsigned long resource_mem_flags)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
sp_populate_of(struct sja1000_priv * priv,struct device_node * of)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
sp_probe(struct platform_device * pdev)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_nocache(&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
sp_remove(struct platform_device * pdev)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
