xref: /openbmc/linux/drivers/input/serio/arc_ps2.c (revision 0da85d1e) 
1 /*
2  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  * Driver is originally developed by Pavel Sokolov <psokolov@synopsys.com>
9  */
10 
11 #include <linux/err.h>
12 #include <linux/module.h>
13 #include <linux/interrupt.h>
14 #include <linux/input.h>
15 #include <linux/serio.h>
16 #include <linux/platform_device.h>
17 #include <linux/of.h>
18 #include <linux/io.h>
19 #include <linux/kernel.h>
20 #include <linux/slab.h>
21 
22 #define ARC_PS2_PORTS                   2
23 
24 #define ARC_ARC_PS2_ID                  0x0001f609
25 
26 #define STAT_TIMEOUT                    128
27 
28 #define PS2_STAT_RX_FRM_ERR             (1)
29 #define PS2_STAT_RX_BUF_OVER            (1 << 1)
30 #define PS2_STAT_RX_INT_EN              (1 << 2)
31 #define PS2_STAT_RX_VAL                 (1 << 3)
32 #define PS2_STAT_TX_ISNOT_FUL           (1 << 4)
33 #define PS2_STAT_TX_INT_EN              (1 << 5)
34 
35 struct arc_ps2_port {
36 	void __iomem *data_addr;
37 	void __iomem *status_addr;
38 	struct serio *io;
39 };
40 
41 struct arc_ps2_data {
42 	struct arc_ps2_port port[ARC_PS2_PORTS];
43 	void __iomem *addr;
44 	unsigned int frame_error;
45 	unsigned int buf_overflow;
46 	unsigned int total_int;
47 };
48 
49 static void arc_ps2_check_rx(struct arc_ps2_data *arc_ps2,
50 			     struct arc_ps2_port *port)
51 {
52 	unsigned int timeout = 1000;
53 	unsigned int flag, status;
54 	unsigned char data;
55 
56 	do {
57 		status = ioread32(port->status_addr);
58 		if (!(status & PS2_STAT_RX_VAL))
59 			return;
60 
61 		data = ioread32(port->data_addr) & 0xff;
62 
63 		flag = 0;
64 		arc_ps2->total_int++;
65 		if (status & PS2_STAT_RX_FRM_ERR) {
66 			arc_ps2->frame_error++;
67 			flag |= SERIO_PARITY;
68 		} else if (status & PS2_STAT_RX_BUF_OVER) {
69 			arc_ps2->buf_overflow++;
70 			flag |= SERIO_FRAME;
71 		}
72 
73 		serio_interrupt(port->io, data, flag);
74 	} while (--timeout);
75 
76 	dev_err(&port->io->dev, "PS/2 hardware stuck\n");
77 }
78 
79 static irqreturn_t arc_ps2_interrupt(int irq, void *dev)
80 {
81 	struct arc_ps2_data *arc_ps2 = dev;
82 	int i;
83 
84 	for (i = 0; i < ARC_PS2_PORTS; i++)
85 		arc_ps2_check_rx(arc_ps2, &arc_ps2->port[i]);
86 
87 	return IRQ_HANDLED;
88 }
89 
90 static int arc_ps2_write(struct serio *io, unsigned char val)
91 {
92 	unsigned status;
93 	struct arc_ps2_port *port = io->port_data;
94 	int timeout = STAT_TIMEOUT;
95 
96 	do {
97 		status = ioread32(port->status_addr);
98 		cpu_relax();
99 
100 		if (status & PS2_STAT_TX_ISNOT_FUL) {
101 			iowrite32(val & 0xff, port->data_addr);
102 			return 0;
103 		}
104 
105 	} while (--timeout);
106 
107 	dev_err(&io->dev, "write timeout\n");
108 	return -ETIMEDOUT;
109 }
110 
111 static int arc_ps2_open(struct serio *io)
112 {
113 	struct arc_ps2_port *port = io->port_data;
114 
115 	iowrite32(PS2_STAT_RX_INT_EN, port->status_addr);
116 
117 	return 0;
118 }
119 
120 static void arc_ps2_close(struct serio *io)
121 {
122 	struct arc_ps2_port *port = io->port_data;
123 
124 	iowrite32(ioread32(port->status_addr) & ~PS2_STAT_RX_INT_EN,
125 		  port->status_addr);
126 }
127 
128 static void __iomem *arc_ps2_calc_addr(struct arc_ps2_data *arc_ps2,
129 						  int index, bool status)
130 {
131 	void __iomem *addr;
132 
133 	addr = arc_ps2->addr + 4 + 4 * index;
134 	if (status)
135 		addr += ARC_PS2_PORTS * 4;
136 
137 	return addr;
138 }
139 
140 static void arc_ps2_inhibit_ports(struct arc_ps2_data *arc_ps2)
141 {
142 	void __iomem *addr;
143 	u32 val;
144 	int i;
145 
146 	for (i = 0; i < ARC_PS2_PORTS; i++) {
147 		addr = arc_ps2_calc_addr(arc_ps2, i, true);
148 		val = ioread32(addr);
149 		val &= ~(PS2_STAT_RX_INT_EN | PS2_STAT_TX_INT_EN);
150 		iowrite32(val, addr);
151 	}
152 }
153 
154 static int arc_ps2_create_port(struct platform_device *pdev,
155 					 struct arc_ps2_data *arc_ps2,
156 					 int index)
157 {
158 	struct arc_ps2_port *port = &arc_ps2->port[index];
159 	struct serio *io;
160 
161 	io = kzalloc(sizeof(struct serio), GFP_KERNEL);
162 	if (!io)
163 		return -ENOMEM;
164 
165 	io->id.type = SERIO_8042;
166 	io->write = arc_ps2_write;
167 	io->open = arc_ps2_open;
168 	io->close = arc_ps2_close;
169 	snprintf(io->name, sizeof(io->name), "ARC PS/2 port%d", index);
170 	snprintf(io->phys, sizeof(io->phys), "arc/serio%d", index);
171 	io->port_data = port;
172 
173 	port->io = io;
174 
175 	port->data_addr = arc_ps2_calc_addr(arc_ps2, index, false);
176 	port->status_addr = arc_ps2_calc_addr(arc_ps2, index, true);
177 
178 	dev_dbg(&pdev->dev, "port%d is allocated (data = 0x%p, status = 0x%p)\n",
179 		index, port->data_addr, port->status_addr);
180 
181 	serio_register_port(port->io);
182 	return 0;
183 }
184 
185 static int arc_ps2_probe(struct platform_device *pdev)
186 {
187 	struct arc_ps2_data *arc_ps2;
188 	struct resource *res;
189 	int irq;
190 	int error, id, i;
191 
192 	irq = platform_get_irq_byname(pdev, "arc_ps2_irq");
193 	if (irq < 0) {
194 		dev_err(&pdev->dev, "no IRQ defined\n");
195 		return -EINVAL;
196 	}
197 
198 	arc_ps2 = devm_kzalloc(&pdev->dev, sizeof(struct arc_ps2_data),
199 				GFP_KERNEL);
200 	if (!arc_ps2) {
201 		dev_err(&pdev->dev, "out of memory\n");
202 		return -ENOMEM;
203 	}
204 
205 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
206 	arc_ps2->addr = devm_ioremap_resource(&pdev->dev, res);
207 	if (IS_ERR(arc_ps2->addr))
208 		return PTR_ERR(arc_ps2->addr);
209 
210 	dev_info(&pdev->dev, "irq = %d, address = 0x%p, ports = %i\n",
211 		 irq, arc_ps2->addr, ARC_PS2_PORTS);
212 
213 	id = ioread32(arc_ps2->addr);
214 	if (id != ARC_ARC_PS2_ID) {
215 		dev_err(&pdev->dev, "device id does not match\n");
216 		return -ENXIO;
217 	}
218 
219 	arc_ps2_inhibit_ports(arc_ps2);
220 
221 	error = devm_request_irq(&pdev->dev, irq, arc_ps2_interrupt,
222 				 0, "arc_ps2", arc_ps2);
223 	if (error) {
224 		dev_err(&pdev->dev, "Could not allocate IRQ\n");
225 		return error;
226 	}
227 
228 	for (i = 0; i < ARC_PS2_PORTS; i++) {
229 		error = arc_ps2_create_port(pdev, arc_ps2, i);
230 		if (error) {
231 			while (--i >= 0)
232 				serio_unregister_port(arc_ps2->port[i].io);
233 			return error;
234 		}
235 	}
236 
237 	platform_set_drvdata(pdev, arc_ps2);
238 
239 	return 0;
240 }
241 
242 static int arc_ps2_remove(struct platform_device *pdev)
243 {
244 	struct arc_ps2_data *arc_ps2 = platform_get_drvdata(pdev);
245 	int i;
246 
247 	for (i = 0; i < ARC_PS2_PORTS; i++)
248 		serio_unregister_port(arc_ps2->port[i].io);
249 
250 	dev_dbg(&pdev->dev, "interrupt count = %i\n", arc_ps2->total_int);
251 	dev_dbg(&pdev->dev, "frame error count = %i\n", arc_ps2->frame_error);
252 	dev_dbg(&pdev->dev, "buffer overflow count = %i\n",
253 		arc_ps2->buf_overflow);
254 
255 	return 0;
256 }
257 
258 #ifdef CONFIG_OF
259 static const struct of_device_id arc_ps2_match[] = {
260 	{ .compatible = "snps,arc_ps2" },
261 	{ },
262 };
263 MODULE_DEVICE_TABLE(of, arc_ps2_match);
264 #endif
265 
266 static struct platform_driver arc_ps2_driver = {
267 	.driver	= {
268 		.name		= "arc_ps2",
269 		.of_match_table	= of_match_ptr(arc_ps2_match),
270 	},
271 	.probe	= arc_ps2_probe,
272 	.remove	= arc_ps2_remove,
273 };
274 
275 module_platform_driver(arc_ps2_driver);
276 
277 MODULE_LICENSE("GPL");
278 MODULE_AUTHOR("Pavel Sokolov <psokolov@synopsys.com>");
279 MODULE_DESCRIPTION("ARC PS/2 Driver");
280