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