1 // SPDX-License-Identifier: GPL-2.0
2 // IOMapped CAN bus driver for Bosch M_CAN controller
3 // Copyright (C) 2014 Freescale Semiconductor, Inc.
4 //	Dong Aisheng <b29396@freescale.com>
5 //
6 // Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/
7 
8 #include <linux/hrtimer.h>
9 #include <linux/phy/phy.h>
10 #include <linux/platform_device.h>
11 
12 #include "m_can.h"
13 
14 struct m_can_plat_priv {
15 	struct m_can_classdev cdev;
16 
17 	void __iomem *base;
18 	void __iomem *mram_base;
19 };
20 
21 static inline struct m_can_plat_priv *cdev_to_priv(struct m_can_classdev *cdev)
22 {
23 	return container_of(cdev, struct m_can_plat_priv, cdev);
24 }
25 
26 static u32 iomap_read_reg(struct m_can_classdev *cdev, int reg)
27 {
28 	struct m_can_plat_priv *priv = cdev_to_priv(cdev);
29 
30 	return readl(priv->base + reg);
31 }
32 
33 static int iomap_read_fifo(struct m_can_classdev *cdev, int offset, void *val, size_t val_count)
34 {
35 	struct m_can_plat_priv *priv = cdev_to_priv(cdev);
36 	void __iomem *src = priv->mram_base + offset;
37 
38 	while (val_count--) {
39 		*(unsigned int *)val = ioread32(src);
40 		val += 4;
41 		src += 4;
42 	}
43 
44 	return 0;
45 }
46 
47 static int iomap_write_reg(struct m_can_classdev *cdev, int reg, int val)
48 {
49 	struct m_can_plat_priv *priv = cdev_to_priv(cdev);
50 
51 	writel(val, priv->base + reg);
52 
53 	return 0;
54 }
55 
56 static int iomap_write_fifo(struct m_can_classdev *cdev, int offset,
57 			    const void *val, size_t val_count)
58 {
59 	struct m_can_plat_priv *priv = cdev_to_priv(cdev);
60 	void __iomem *dst = priv->mram_base + offset;
61 
62 	while (val_count--) {
63 		iowrite32(*(unsigned int *)val, dst);
64 		val += 4;
65 		dst += 4;
66 	}
67 
68 	return 0;
69 }
70 
71 static struct m_can_ops m_can_plat_ops = {
72 	.read_reg = iomap_read_reg,
73 	.write_reg = iomap_write_reg,
74 	.write_fifo = iomap_write_fifo,
75 	.read_fifo = iomap_read_fifo,
76 };
77 
78 static int m_can_plat_probe(struct platform_device *pdev)
79 {
80 	struct m_can_classdev *mcan_class;
81 	struct m_can_plat_priv *priv;
82 	struct resource *res;
83 	void __iomem *addr;
84 	void __iomem *mram_addr;
85 	struct phy *transceiver;
86 	int irq = 0, ret = 0;
87 
88 	mcan_class = m_can_class_allocate_dev(&pdev->dev,
89 					      sizeof(struct m_can_plat_priv));
90 	if (!mcan_class)
91 		return -ENOMEM;
92 
93 	priv = cdev_to_priv(mcan_class);
94 
95 	ret = m_can_class_get_clocks(mcan_class);
96 	if (ret)
97 		goto probe_fail;
98 
99 	addr = devm_platform_ioremap_resource_byname(pdev, "m_can");
100 	if (IS_ERR(addr)) {
101 		ret = PTR_ERR(addr);
102 		goto probe_fail;
103 	}
104 
105 	if (device_property_present(mcan_class->dev, "interrupts") ||
106 	    device_property_present(mcan_class->dev, "interrupt-names")) {
107 		irq = platform_get_irq_byname(pdev, "int0");
108 		if (irq < 0) {
109 			ret = irq;
110 			goto probe_fail;
111 		}
112 	} else {
113 		dev_dbg(mcan_class->dev, "Polling enabled, initialize hrtimer");
114 		hrtimer_init(&mcan_class->hrtimer, CLOCK_MONOTONIC,
115 			     HRTIMER_MODE_REL_PINNED);
116 	}
117 
118 	/* message ram could be shared */
119 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram");
120 	if (!res) {
121 		ret = -ENODEV;
122 		goto probe_fail;
123 	}
124 
125 	mram_addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
126 	if (!mram_addr) {
127 		ret = -ENOMEM;
128 		goto probe_fail;
129 	}
130 
131 	transceiver = devm_phy_optional_get(&pdev->dev, NULL);
132 	if (IS_ERR(transceiver)) {
133 		ret = PTR_ERR(transceiver);
134 		dev_err_probe(&pdev->dev, ret, "failed to get phy\n");
135 		goto probe_fail;
136 	}
137 
138 	if (transceiver)
139 		mcan_class->can.bitrate_max = transceiver->attrs.max_link_rate;
140 
141 	priv->base = addr;
142 	priv->mram_base = mram_addr;
143 
144 	mcan_class->net->irq = irq;
145 	mcan_class->pm_clock_support = 1;
146 	mcan_class->can.clock.freq = clk_get_rate(mcan_class->cclk);
147 	mcan_class->dev = &pdev->dev;
148 	mcan_class->transceiver = transceiver;
149 
150 	mcan_class->ops = &m_can_plat_ops;
151 
152 	mcan_class->is_peripheral = false;
153 
154 	platform_set_drvdata(pdev, mcan_class);
155 
156 	pm_runtime_enable(mcan_class->dev);
157 	ret = m_can_class_register(mcan_class);
158 	if (ret)
159 		goto out_runtime_disable;
160 
161 	return ret;
162 
163 out_runtime_disable:
164 	pm_runtime_disable(mcan_class->dev);
165 probe_fail:
166 	m_can_class_free_dev(mcan_class->net);
167 	return ret;
168 }
169 
170 static __maybe_unused int m_can_suspend(struct device *dev)
171 {
172 	return m_can_class_suspend(dev);
173 }
174 
175 static __maybe_unused int m_can_resume(struct device *dev)
176 {
177 	return m_can_class_resume(dev);
178 }
179 
180 static void m_can_plat_remove(struct platform_device *pdev)
181 {
182 	struct m_can_plat_priv *priv = platform_get_drvdata(pdev);
183 	struct m_can_classdev *mcan_class = &priv->cdev;
184 
185 	m_can_class_unregister(mcan_class);
186 
187 	m_can_class_free_dev(mcan_class->net);
188 }
189 
190 static int __maybe_unused m_can_runtime_suspend(struct device *dev)
191 {
192 	struct m_can_plat_priv *priv = dev_get_drvdata(dev);
193 	struct m_can_classdev *mcan_class = &priv->cdev;
194 
195 	clk_disable_unprepare(mcan_class->cclk);
196 	clk_disable_unprepare(mcan_class->hclk);
197 
198 	return 0;
199 }
200 
201 static int __maybe_unused m_can_runtime_resume(struct device *dev)
202 {
203 	struct m_can_plat_priv *priv = dev_get_drvdata(dev);
204 	struct m_can_classdev *mcan_class = &priv->cdev;
205 	int err;
206 
207 	err = clk_prepare_enable(mcan_class->hclk);
208 	if (err)
209 		return err;
210 
211 	err = clk_prepare_enable(mcan_class->cclk);
212 	if (err)
213 		clk_disable_unprepare(mcan_class->hclk);
214 
215 	return err;
216 }
217 
218 static const struct dev_pm_ops m_can_pmops = {
219 	SET_RUNTIME_PM_OPS(m_can_runtime_suspend,
220 			   m_can_runtime_resume, NULL)
221 	SET_SYSTEM_SLEEP_PM_OPS(m_can_suspend, m_can_resume)
222 };
223 
224 static const struct of_device_id m_can_of_table[] = {
225 	{ .compatible = "bosch,m_can", .data = NULL },
226 	{ /* sentinel */ },
227 };
228 MODULE_DEVICE_TABLE(of, m_can_of_table);
229 
230 static struct platform_driver m_can_plat_driver = {
231 	.driver = {
232 		.name = KBUILD_MODNAME,
233 		.of_match_table = m_can_of_table,
234 		.pm     = &m_can_pmops,
235 	},
236 	.probe = m_can_plat_probe,
237 	.remove_new = m_can_plat_remove,
238 };
239 
240 module_platform_driver(m_can_plat_driver);
241 
242 MODULE_AUTHOR("Dong Aisheng <b29396@freescale.com>");
243 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
244 MODULE_LICENSE("GPL v2");
245 MODULE_DESCRIPTION("M_CAN driver for IO Mapped Bosch controllers");
246