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
52MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
53MODULE_DESCRIPTION("Socket-CAN driver for CC770 on the platform bus");
54MODULE_LICENSE("GPL v2");
55MODULE_ALIAS("platform:" DRV_NAME);
56
57#define CC770_PLATFORM_CAN_CLOCK  16000000
58
59static u8 cc770_platform_read_reg(const struct cc770_priv *priv, int reg)
60{
61	return ioread8(priv->reg_base + reg);
62}
63
64static 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
70static 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_property_read_bool(np, "bosch,divide-memory-clock"))
97		priv->cpu_interface |= CPUIF_DMC;
98	if (of_property_read_bool(np, "bosch,iso-low-speed-mux"))
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_property_read_bool(np, "bosch,disconnect-rx0-input"))
104		priv->bus_config |= BUSCFG_DR0;
105	if (of_property_read_bool(np, "bosch,disconnect-rx1-input"))
106		priv->bus_config |= BUSCFG_DR1;
107	if (of_property_read_bool(np, "bosch,disconnect-tx1-output"))
108		priv->bus_config |= BUSCFG_DT1;
109	if (of_property_read_bool(np, "bosch,polarity-dominant"))
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
143static 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
159static 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
223exit_free_cc770:
224	free_cc770dev(dev);
225exit_unmap_mem:
226	iounmap(base);
227exit_release_mem:
228	release_mem_region(mem->start, mem_size);
229
230	return err;
231}
232
233static void 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
247static const struct of_device_id cc770_platform_table[] = {
248	{.compatible = "bosch,cc770"}, /* CC770 from Bosch */
249	{.compatible = "intc,82527"},  /* AN82527 from Intel CP */
250	{},
251};
252MODULE_DEVICE_TABLE(of, cc770_platform_table);
253
254static struct platform_driver cc770_platform_driver = {
255	.driver = {
256		.name = DRV_NAME,
257		.of_match_table = cc770_platform_table,
258	},
259	.probe = cc770_platform_probe,
260	.remove_new = cc770_platform_remove,
261};
262
263module_platform_driver(cc770_platform_driver);
264