1 // SPDX-License-Identifier: GPL-2.0
2 /* DSA driver for:
3  * Vitesse VSC7385 SparX-G5 5+1-port Integrated Gigabit Ethernet Switch
4  * Vitesse VSC7388 SparX-G8 8-port Integrated Gigabit Ethernet Switch
5  * Vitesse VSC7395 SparX-G5e 5+1-port Integrated Gigabit Ethernet Switch
6  * Vitesse VSC7398 SparX-G8e 8-port Integrated Gigabit Ethernet Switch
7  *
8  * This driver takes control of the switch chip connected over CPU-attached
9  * address bus and configures it to route packages around when connected to
10  * a CPU port.
11  *
12  * Copyright (C) 2019 Pawel Dembicki <paweldembicki@gmail.com>
13  * Based on vitesse-vsc-spi.c by:
14  * Copyright (C) 2018 Linus Wallej <linus.walleij@linaro.org>
15  * Includes portions of code from the firmware uploader by:
16  * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
17  */
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 #include <linux/platform_device.h>
22 
23 #include "vitesse-vsc73xx.h"
24 
25 #define VSC73XX_CMD_PLATFORM_BLOCK_SHIFT		14
26 #define VSC73XX_CMD_PLATFORM_BLOCK_MASK			0x7
27 #define VSC73XX_CMD_PLATFORM_SUBBLOCK_SHIFT		10
28 #define VSC73XX_CMD_PLATFORM_SUBBLOCK_MASK		0xf
29 #define VSC73XX_CMD_PLATFORM_REGISTER_SHIFT		2
30 
31 /**
32  * struct vsc73xx_platform - VSC73xx Platform state container
33  */
34 struct vsc73xx_platform {
35 	struct platform_device	*pdev;
36 	void __iomem		*base_addr;
37 	struct vsc73xx		vsc;
38 };
39 
40 static const struct vsc73xx_ops vsc73xx_platform_ops;
41 
42 static u32 vsc73xx_make_addr(u8 block, u8 subblock, u8 reg)
43 {
44 	u32 ret;
45 
46 	ret = (block & VSC73XX_CMD_PLATFORM_BLOCK_MASK)
47 	    << VSC73XX_CMD_PLATFORM_BLOCK_SHIFT;
48 	ret |= (subblock & VSC73XX_CMD_PLATFORM_SUBBLOCK_MASK)
49 	    << VSC73XX_CMD_PLATFORM_SUBBLOCK_SHIFT;
50 	ret |= reg << VSC73XX_CMD_PLATFORM_REGISTER_SHIFT;
51 
52 	return ret;
53 }
54 
55 static int vsc73xx_platform_read(struct vsc73xx *vsc, u8 block, u8 subblock,
56 				 u8 reg, u32 *val)
57 {
58 	struct vsc73xx_platform *vsc_platform = vsc->priv;
59 	u32 offset;
60 
61 	if (!vsc73xx_is_addr_valid(block, subblock))
62 		return -EINVAL;
63 
64 	offset = vsc73xx_make_addr(block, subblock, reg);
65 	/* By default vsc73xx running in big-endian mode.
66 	 * (See "Register Addressing" section 5.5.3 in the VSC7385 manual.)
67 	 */
68 	*val = ioread32be(vsc_platform->base_addr + offset);
69 
70 	return 0;
71 }
72 
73 static int vsc73xx_platform_write(struct vsc73xx *vsc, u8 block, u8 subblock,
74 				  u8 reg, u32 val)
75 {
76 	struct vsc73xx_platform *vsc_platform = vsc->priv;
77 	u32 offset;
78 
79 	if (!vsc73xx_is_addr_valid(block, subblock))
80 		return -EINVAL;
81 
82 	offset = vsc73xx_make_addr(block, subblock, reg);
83 	iowrite32be(val, vsc_platform->base_addr + offset);
84 
85 	return 0;
86 }
87 
88 static int vsc73xx_platform_probe(struct platform_device *pdev)
89 {
90 	struct device *dev = &pdev->dev;
91 	struct vsc73xx_platform *vsc_platform;
92 	struct resource *res = NULL;
93 	int ret;
94 
95 	vsc_platform = devm_kzalloc(dev, sizeof(*vsc_platform), GFP_KERNEL);
96 	if (!vsc_platform)
97 		return -ENOMEM;
98 
99 	platform_set_drvdata(pdev, vsc_platform);
100 	vsc_platform->pdev = pdev;
101 	vsc_platform->vsc.dev = dev;
102 	vsc_platform->vsc.priv = vsc_platform;
103 	vsc_platform->vsc.ops = &vsc73xx_platform_ops;
104 
105 	/* obtain I/O memory space */
106 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
107 	if (!res) {
108 		dev_err(&pdev->dev, "cannot obtain I/O memory space\n");
109 		ret = -ENXIO;
110 		return ret;
111 	}
112 
113 	vsc_platform->base_addr = devm_ioremap_resource(&pdev->dev, res);
114 	if (IS_ERR(vsc_platform->base_addr)) {
115 		dev_err(&pdev->dev, "cannot request I/O memory space\n");
116 		ret = -ENXIO;
117 		return ret;
118 	}
119 
120 	return vsc73xx_probe(&vsc_platform->vsc);
121 }
122 
123 static int vsc73xx_platform_remove(struct platform_device *pdev)
124 {
125 	struct vsc73xx_platform *vsc_platform = platform_get_drvdata(pdev);
126 
127 	return vsc73xx_remove(&vsc_platform->vsc);
128 }
129 
130 static const struct vsc73xx_ops vsc73xx_platform_ops = {
131 	.read = vsc73xx_platform_read,
132 	.write = vsc73xx_platform_write,
133 };
134 
135 static const struct of_device_id vsc73xx_of_match[] = {
136 	{
137 		.compatible = "vitesse,vsc7385",
138 	},
139 	{
140 		.compatible = "vitesse,vsc7388",
141 	},
142 	{
143 		.compatible = "vitesse,vsc7395",
144 	},
145 	{
146 		.compatible = "vitesse,vsc7398",
147 	},
148 	{ },
149 };
150 MODULE_DEVICE_TABLE(of, vsc73xx_of_match);
151 
152 static struct platform_driver vsc73xx_platform_driver = {
153 	.probe = vsc73xx_platform_probe,
154 	.remove = vsc73xx_platform_remove,
155 	.driver = {
156 		.name = "vsc73xx-platform",
157 		.of_match_table = vsc73xx_of_match,
158 	},
159 };
160 module_platform_driver(vsc73xx_platform_driver);
161 
162 MODULE_AUTHOR("Pawel Dembicki <paweldembicki@gmail.com>");
163 MODULE_DESCRIPTION("Vitesse VSC7385/7388/7395/7398 Platform driver");
164 MODULE_LICENSE("GPL v2");
165