1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Driver for CC770 and AN82527 CAN controllers on the platform bus
4 *
5 * Copyright (C) 2009, 2011 Wolfgang Grandegger <wg@grandegger.com>
6 */
7
8 /*
9 * If platform data are used you should have similar definitions
10 * in your board-specific code:
11 *
12 * static struct cc770_platform_data myboard_cc770_pdata = {
13 * .osc_freq = 16000000,
14 * .cir = 0x41,
15 * .cor = 0x20,
16 * .bcr = 0x40,
17 * };
18 *
19 * Please see include/linux/can/platform/cc770.h for description of
20 * above fields.
21 *
22 * If the device tree is used, you need a CAN node definition in your
23 * DTS file similar to:
24 *
25 * can@3,100 {
26 * compatible = "bosch,cc770";
27 * reg = <3 0x100 0x80>;
28 * interrupts = <2 0>;
29 * interrupt-parent = <&mpic>;
30 * bosch,external-clock-frequency = <16000000>;
31 * };
32 *
33 * See "Documentation/devicetree/bindings/net/can/cc770.txt" for further
34 * information.
35 */
36
37 #include <linux/kernel.h>
38 #include <linux/module.h>
39 #include <linux/interrupt.h>
40 #include <linux/netdevice.h>
41 #include <linux/delay.h>
42 #include <linux/platform_device.h>
43 #include <linux/of.h>
44 #include <linux/can.h>
45 #include <linux/can/dev.h>
46 #include <linux/can/platform/cc770.h>
47
48 #include "cc770.h"
49
50 #define DRV_NAME "cc770_platform"
51
52 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
53 MODULE_DESCRIPTION("Socket-CAN driver for CC770 on the platform bus");
54 MODULE_LICENSE("GPL v2");
55 MODULE_ALIAS("platform:" DRV_NAME);
56
57 #define CC770_PLATFORM_CAN_CLOCK 16000000
58
cc770_platform_read_reg(const struct cc770_priv * priv,int reg)59 static u8 cc770_platform_read_reg(const struct cc770_priv *priv, int reg)
60 {
61 return ioread8(priv->reg_base + reg);
62 }
63
cc770_platform_write_reg(const struct cc770_priv * priv,int reg,u8 val)64 static void cc770_platform_write_reg(const struct cc770_priv *priv, int reg,
65 u8 val)
66 {
67 iowrite8(val, priv->reg_base + reg);
68 }
69
cc770_get_of_node_data(struct platform_device * pdev,struct cc770_priv * priv)70 static int cc770_get_of_node_data(struct platform_device *pdev,
71 struct cc770_priv *priv)
72 {
73 struct device_node *np = pdev->dev.of_node;
74 const u32 *prop;
75 int prop_size;
76 u32 clkext;
77
78 prop = of_get_property(np, "bosch,external-clock-frequency",
79 &prop_size);
80 if (prop && (prop_size == sizeof(u32)))
81 clkext = *prop;
82 else
83 clkext = CC770_PLATFORM_CAN_CLOCK; /* default */
84 priv->can.clock.freq = clkext;
85
86 /* The system clock may not exceed 10 MHz */
87 if (priv->can.clock.freq > 10000000) {
88 priv->cpu_interface |= CPUIF_DSC;
89 priv->can.clock.freq /= 2;
90 }
91
92 /* The memory clock may not exceed 8 MHz */
93 if (priv->can.clock.freq > 8000000)
94 priv->cpu_interface |= CPUIF_DMC;
95
96 if (of_get_property(np, "bosch,divide-memory-clock", NULL))
97 priv->cpu_interface |= CPUIF_DMC;
98 if (of_get_property(np, "bosch,iso-low-speed-mux", NULL))
99 priv->cpu_interface |= CPUIF_MUX;
100
101 if (!of_get_property(np, "bosch,no-comperator-bypass", NULL))
102 priv->bus_config |= BUSCFG_CBY;
103 if (of_get_property(np, "bosch,disconnect-rx0-input", NULL))
104 priv->bus_config |= BUSCFG_DR0;
105 if (of_get_property(np, "bosch,disconnect-rx1-input", NULL))
106 priv->bus_config |= BUSCFG_DR1;
107 if (of_get_property(np, "bosch,disconnect-tx1-output", NULL))
108 priv->bus_config |= BUSCFG_DT1;
109 if (of_get_property(np, "bosch,polarity-dominant", NULL))
110 priv->bus_config |= BUSCFG_POL;
111
112 prop = of_get_property(np, "bosch,clock-out-frequency", &prop_size);
113 if (prop && (prop_size == sizeof(u32)) && *prop > 0) {
114 u32 cdv = clkext / *prop;
115 int slew;
116
117 if (cdv > 0 && cdv < 16) {
118 priv->cpu_interface |= CPUIF_CEN;
119 priv->clkout |= (cdv - 1) & CLKOUT_CD_MASK;
120
121 prop = of_get_property(np, "bosch,slew-rate",
122 &prop_size);
123 if (prop && (prop_size == sizeof(u32))) {
124 slew = *prop;
125 } else {
126 /* Determine default slew rate */
127 slew = (CLKOUT_SL_MASK >>
128 CLKOUT_SL_SHIFT) -
129 ((cdv * clkext - 1) / 8000000);
130 if (slew < 0)
131 slew = 0;
132 }
133 priv->clkout |= (slew << CLKOUT_SL_SHIFT) &
134 CLKOUT_SL_MASK;
135 } else {
136 dev_dbg(&pdev->dev, "invalid clock-out-frequency\n");
137 }
138 }
139
140 return 0;
141 }
142
cc770_get_platform_data(struct platform_device * pdev,struct cc770_priv * priv)143 static int cc770_get_platform_data(struct platform_device *pdev,
144 struct cc770_priv *priv)
145 {
146
147 struct cc770_platform_data *pdata = dev_get_platdata(&pdev->dev);
148
149 priv->can.clock.freq = pdata->osc_freq;
150 if (priv->cpu_interface & CPUIF_DSC)
151 priv->can.clock.freq /= 2;
152 priv->clkout = pdata->cor;
153 priv->bus_config = pdata->bcr;
154 priv->cpu_interface = pdata->cir;
155
156 return 0;
157 }
158
cc770_platform_probe(struct platform_device * pdev)159 static int cc770_platform_probe(struct platform_device *pdev)
160 {
161 struct net_device *dev;
162 struct cc770_priv *priv;
163 struct resource *mem;
164 resource_size_t mem_size;
165 void __iomem *base;
166 int err, irq;
167
168 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
169 irq = platform_get_irq(pdev, 0);
170 if (!mem || irq <= 0)
171 return -ENODEV;
172
173 mem_size = resource_size(mem);
174 if (!request_mem_region(mem->start, mem_size, pdev->name))
175 return -EBUSY;
176
177 base = ioremap(mem->start, mem_size);
178 if (!base) {
179 err = -ENOMEM;
180 goto exit_release_mem;
181 }
182
183 dev = alloc_cc770dev(0);
184 if (!dev) {
185 err = -ENOMEM;
186 goto exit_unmap_mem;
187 }
188
189 dev->irq = irq;
190 priv = netdev_priv(dev);
191 priv->read_reg = cc770_platform_read_reg;
192 priv->write_reg = cc770_platform_write_reg;
193 priv->irq_flags = IRQF_SHARED;
194 priv->reg_base = base;
195
196 if (pdev->dev.of_node)
197 err = cc770_get_of_node_data(pdev, priv);
198 else if (dev_get_platdata(&pdev->dev))
199 err = cc770_get_platform_data(pdev, priv);
200 else
201 err = -ENODEV;
202 if (err)
203 goto exit_free_cc770;
204
205 dev_dbg(&pdev->dev,
206 "reg_base=0x%p irq=%d clock=%d cpu_interface=0x%02x "
207 "bus_config=0x%02x clkout=0x%02x\n",
208 priv->reg_base, dev->irq, priv->can.clock.freq,
209 priv->cpu_interface, priv->bus_config, priv->clkout);
210
211 platform_set_drvdata(pdev, dev);
212 SET_NETDEV_DEV(dev, &pdev->dev);
213
214 err = register_cc770dev(dev);
215 if (err) {
216 dev_err(&pdev->dev,
217 "couldn't register CC700 device (err=%d)\n", err);
218 goto exit_free_cc770;
219 }
220
221 return 0;
222
223 exit_free_cc770:
224 free_cc770dev(dev);
225 exit_unmap_mem:
226 iounmap(base);
227 exit_release_mem:
228 release_mem_region(mem->start, mem_size);
229
230 return err;
231 }
232
cc770_platform_remove(struct platform_device * pdev)233 static int cc770_platform_remove(struct platform_device *pdev)
234 {
235 struct net_device *dev = platform_get_drvdata(pdev);
236 struct cc770_priv *priv = netdev_priv(dev);
237 struct resource *mem;
238
239 unregister_cc770dev(dev);
240 iounmap(priv->reg_base);
241 free_cc770dev(dev);
242
243 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
244 release_mem_region(mem->start, resource_size(mem));
245
246 return 0;
247 }
248
249 static const struct of_device_id cc770_platform_table[] = {
250 {.compatible = "bosch,cc770"}, /* CC770 from Bosch */
251 {.compatible = "intc,82527"}, /* AN82527 from Intel CP */
252 {},
253 };
254 MODULE_DEVICE_TABLE(of, cc770_platform_table);
255
256 static struct platform_driver cc770_platform_driver = {
257 .driver = {
258 .name = DRV_NAME,
259 .of_match_table = cc770_platform_table,
260 },
261 .probe = cc770_platform_probe,
262 .remove = cc770_platform_remove,
263 };
264
265 module_platform_driver(cc770_platform_driver);
266