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
32struct arc_ps2_port {
33 void __iomem *data_addr;
34 void __iomem *status_addr;
35 struct serio *io;
36};
37
38struct 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
46static 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(serio: port->io, data, flags: flag);
71 } while (--timeout);
72
73 dev_err(&port->io->dev, "PS/2 hardware stuck\n");
74}
75
76static 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, port: &arc_ps2->port[i]);
83
84 return IRQ_HANDLED;
85}
86
87static 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
108static 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
117static 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
125static 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
137static 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, index: i, status: true);
145 val = ioread32(addr);
146 val &= ~(PS2_STAT_RX_INT_EN | PS2_STAT_TX_INT_EN);
147 iowrite32(val, addr);
148 }
149}
150
151static 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(*io), 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(buf: io->name, size: sizeof(io->name), fmt: "ARC PS/2 port%d", index);
167 snprintf(buf: io->phys, size: sizeof(io->phys), fmt: "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, status: false);
173 port->status_addr = arc_ps2_calc_addr(arc_ps2, index, status: 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
182static 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(dev: &pdev->dev, size: 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, index: 0, NULL);
200 if (IS_ERR(ptr: arc_ps2->addr))
201 return PTR_ERR(ptr: 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(dev: &pdev->dev, irq, handler: arc_ps2_interrupt,
215 irqflags: 0, devname: "arc_ps2", dev_id: 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, index: i);
223 if (error) {
224 while (--i >= 0)
225 serio_unregister_port(serio: arc_ps2->port[i].io);
226 return error;
227 }
228 }
229
230 platform_set_drvdata(pdev, data: arc_ps2);
231
232 return 0;
233}
234
235static void 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(serio: 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
249#ifdef CONFIG_OF
250static const struct of_device_id arc_ps2_match[] = {
251 { .compatible = "snps,arc_ps2" },
252 { },
253};
254MODULE_DEVICE_TABLE(of, arc_ps2_match);
255#endif
256
257static struct platform_driver arc_ps2_driver = {
258 .driver = {
259 .name = "arc_ps2",
260 .of_match_table = of_match_ptr(arc_ps2_match),
261 },
262 .probe = arc_ps2_probe,
263 .remove = arc_ps2_remove,
264};
265
266module_platform_driver(arc_ps2_driver);
267
268MODULE_LICENSE("GPL");
269MODULE_AUTHOR("Pavel Sokolov <psokolov@synopsys.com>");
270MODULE_DESCRIPTION("ARC PS/2 Driver");
271

source code of linux/drivers/input/serio/arc_ps2.c