xref: /openbmc/linux/drivers/input/serio/arc_ps2.c (revision fa0dadde) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4  *
5  * Driver is originally developed by Pavel Sokolov <psokolov@synopsys.com>
6  */
7 
8 #include <linux/err.h>
9 #include <linux/module.h>
10 #include <linux/interrupt.h>
11 #include <linux/input.h>
12 #include <linux/serio.h>
13 #include <linux/platform_device.h>
14 #include <linux/of.h>
15 #include <linux/io.h>
16 #include <linux/kernel.h>
17 #include <linux/slab.h>
18 
19 #define ARC_PS2_PORTS                   2
20 
21 #define ARC_ARC_PS2_ID                  0x0001f609
22 
23 #define STAT_TIMEOUT                    128
24 
25 #define PS2_STAT_RX_FRM_ERR             (1)
26 #define PS2_STAT_RX_BUF_OVER            (1 << 1)
27 #define PS2_STAT_RX_INT_EN              (1 << 2)
28 #define PS2_STAT_RX_VAL                 (1 << 3)
29 #define PS2_STAT_TX_ISNOT_FUL           (1 << 4)
30 #define PS2_STAT_TX_INT_EN              (1 << 5)
31 
32 struct arc_ps2_port {
33 	void __iomem *data_addr;
34 	void __iomem *status_addr;
35 	struct serio *io;
36 };
37 
38 struct arc_ps2_data {
39 	struct arc_ps2_port port[ARC_PS2_PORTS];
40 	void __iomem *addr;
41 	unsigned int frame_error;
42 	unsigned int buf_overflow;
43 	unsigned int total_int;
44 };
45 
46 static void arc_ps2_check_rx(struct arc_ps2_data *arc_ps2,
47 			     struct arc_ps2_port *port)
48 {
49 	unsigned int timeout = 1000;
50 	unsigned int flag, status;
51 	unsigned char data;
52 
53 	do {
54 		status = ioread32(port->status_addr);
55 		if (!(status & PS2_STAT_RX_VAL))
56 			return;
57 
58 		data = ioread32(port->data_addr) & 0xff;
59 
60 		flag = 0;
61 		arc_ps2->total_int++;
62 		if (status & PS2_STAT_RX_FRM_ERR) {
63 			arc_ps2->frame_error++;
64 			flag |= SERIO_PARITY;
65 		} else if (status & PS2_STAT_RX_BUF_OVER) {
66 			arc_ps2->buf_overflow++;
67 			flag |= SERIO_FRAME;
68 		}
69 
70 		serio_interrupt(port->io, data, flag);
71 	} while (--timeout);
72 
73 	dev_err(&port->io->dev, "PS/2 hardware stuck\n");
74 }
75 
76 static irqreturn_t arc_ps2_interrupt(int irq, void *dev)
77 {
78 	struct arc_ps2_data *arc_ps2 = dev;
79 	int i;
80 
81 	for (i = 0; i < ARC_PS2_PORTS; i++)
82 		arc_ps2_check_rx(arc_ps2, &arc_ps2->port[i]);
83 
84 	return IRQ_HANDLED;
85 }
86 
87 static int arc_ps2_write(struct serio *io, unsigned char val)
88 {
89 	unsigned status;
90 	struct arc_ps2_port *port = io->port_data;
91 	int timeout = STAT_TIMEOUT;
92 
93 	do {
94 		status = ioread32(port->status_addr);
95 		cpu_relax();
96 
97 		if (status & PS2_STAT_TX_ISNOT_FUL) {
98 			iowrite32(val & 0xff, port->data_addr);
99 			return 0;
100 		}
101 
102 	} while (--timeout);
103 
104 	dev_err(&io->dev, "write timeout\n");
105 	return -ETIMEDOUT;
106 }
107 
108 static int arc_ps2_open(struct serio *io)
109 {
110 	struct arc_ps2_port *port = io->port_data;
111 
112 	iowrite32(PS2_STAT_RX_INT_EN, port->status_addr);
113 
114 	return 0;
115 }
116 
117 static void arc_ps2_close(struct serio *io)
118 {
119 	struct arc_ps2_port *port = io->port_data;
120 
121 	iowrite32(ioread32(port->status_addr) & ~PS2_STAT_RX_INT_EN,
122 		  port->status_addr);
123 }
124 
125 static void __iomem *arc_ps2_calc_addr(struct arc_ps2_data *arc_ps2,
126 						  int index, bool status)
127 {
128 	void __iomem *addr;
129 
130 	addr = arc_ps2->addr + 4 + 4 * index;
131 	if (status)
132 		addr += ARC_PS2_PORTS * 4;
133 
134 	return addr;
135 }
136 
137 static void arc_ps2_inhibit_ports(struct arc_ps2_data *arc_ps2)
138 {
139 	void __iomem *addr;
140 	u32 val;
141 	int i;
142 
143 	for (i = 0; i < ARC_PS2_PORTS; i++) {
144 		addr = arc_ps2_calc_addr(arc_ps2, i, true);
145 		val = ioread32(addr);
146 		val &= ~(PS2_STAT_RX_INT_EN | PS2_STAT_TX_INT_EN);
147 		iowrite32(val, addr);
148 	}
149 }
150 
151 static int arc_ps2_create_port(struct platform_device *pdev,
152 					 struct arc_ps2_data *arc_ps2,
153 					 int index)
154 {
155 	struct arc_ps2_port *port = &arc_ps2->port[index];
156 	struct serio *io;
157 
158 	io = kzalloc(sizeof(struct serio), GFP_KERNEL);
159 	if (!io)
160 		return -ENOMEM;
161 
162 	io->id.type = SERIO_8042;
163 	io->write = arc_ps2_write;
164 	io->open = arc_ps2_open;
165 	io->close = arc_ps2_close;
166 	snprintf(io->name, sizeof(io->name), "ARC PS/2 port%d", index);
167 	snprintf(io->phys, sizeof(io->phys), "arc/serio%d", index);
168 	io->port_data = port;
169 
170 	port->io = io;
171 
172 	port->data_addr = arc_ps2_calc_addr(arc_ps2, index, false);
173 	port->status_addr = arc_ps2_calc_addr(arc_ps2, index, true);
174 
175 	dev_dbg(&pdev->dev, "port%d is allocated (data = 0x%p, status = 0x%p)\n",
176 		index, port->data_addr, port->status_addr);
177 
178 	serio_register_port(port->io);
179 	return 0;
180 }
181 
182 static int arc_ps2_probe(struct platform_device *pdev)
183 {
184 	struct arc_ps2_data *arc_ps2;
185 	int irq;
186 	int error, id, i;
187 
188 	irq = platform_get_irq_byname(pdev, "arc_ps2_irq");
189 	if (irq < 0)
190 		return -EINVAL;
191 
192 	arc_ps2 = devm_kzalloc(&pdev->dev, sizeof(struct arc_ps2_data),
193 				GFP_KERNEL);
194 	if (!arc_ps2) {
195 		dev_err(&pdev->dev, "out of memory\n");
196 		return -ENOMEM;
197 	}
198 
199 	arc_ps2->addr = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
200 	if (IS_ERR(arc_ps2->addr))
201 		return PTR_ERR(arc_ps2->addr);
202 
203 	dev_info(&pdev->dev, "irq = %d, address = 0x%p, ports = %i\n",
204 		 irq, arc_ps2->addr, ARC_PS2_PORTS);
205 
206 	id = ioread32(arc_ps2->addr);
207 	if (id != ARC_ARC_PS2_ID) {
208 		dev_err(&pdev->dev, "device id does not match\n");
209 		return -ENXIO;
210 	}
211 
212 	arc_ps2_inhibit_ports(arc_ps2);
213 
214 	error = devm_request_irq(&pdev->dev, irq, arc_ps2_interrupt,
215 				 0, "arc_ps2", arc_ps2);
216 	if (error) {
217 		dev_err(&pdev->dev, "Could not allocate IRQ\n");
218 		return error;
219 	}
220 
221 	for (i = 0; i < ARC_PS2_PORTS; i++) {
222 		error = arc_ps2_create_port(pdev, arc_ps2, i);
223 		if (error) {
224 			while (--i >= 0)
225 				serio_unregister_port(arc_ps2->port[i].io);
226 			return error;
227 		}
228 	}
229 
230 	platform_set_drvdata(pdev, arc_ps2);
231 
232 	return 0;
233 }
234 
235 static int arc_ps2_remove(struct platform_device *pdev)
236 {
237 	struct arc_ps2_data *arc_ps2 = platform_get_drvdata(pdev);
238 	int i;
239 
240 	for (i = 0; i < ARC_PS2_PORTS; i++)
241 		serio_unregister_port(arc_ps2->port[i].io);
242 
243 	dev_dbg(&pdev->dev, "interrupt count = %i\n", arc_ps2->total_int);
244 	dev_dbg(&pdev->dev, "frame error count = %i\n", arc_ps2->frame_error);
245 	dev_dbg(&pdev->dev, "buffer overflow count = %i\n",
246 		arc_ps2->buf_overflow);
247 
248 	return 0;
249 }
250 
251 #ifdef CONFIG_OF
252 static const struct of_device_id arc_ps2_match[] = {
253 	{ .compatible = "snps,arc_ps2" },
254 	{ },
255 };
256 MODULE_DEVICE_TABLE(of, arc_ps2_match);
257 #endif
258 
259 static struct platform_driver arc_ps2_driver = {
260 	.driver	= {
261 		.name		= "arc_ps2",
262 		.of_match_table	= of_match_ptr(arc_ps2_match),
263 	},
264 	.probe	= arc_ps2_probe,
265 	.remove	= arc_ps2_remove,
266 };
267 
268 module_platform_driver(arc_ps2_driver);
269 
270 MODULE_LICENSE("GPL");
271 MODULE_AUTHOR("Pavel Sokolov <psokolov@synopsys.com>");
272 MODULE_DESCRIPTION("ARC PS/2 Driver");
273