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269 lines · 6.1 KiB

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 <[email protected]>
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(port->io, data, 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, &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, 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
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_obj(*io);
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
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(&pdev->dev, sizeof(*arc_ps2), GFP_KERNEL);
193 if (!arc_ps2) {
194 dev_err(&pdev->dev, "out of memory\n");
195 return -ENOMEM;
196 }
197
198 arc_ps2->addr = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
199 if (IS_ERR(arc_ps2->addr))
200 return PTR_ERR(arc_ps2->addr);
201
202 dev_info(&pdev->dev, "irq = %d, address = 0x%p, ports = %i\n",
203 irq, arc_ps2->addr, ARC_PS2_PORTS);
204
205 id = ioread32(arc_ps2->addr);
206 if (id != ARC_ARC_PS2_ID) {
207 dev_err(&pdev->dev, "device id does not match\n");
208 return -ENXIO;
209 }
210
211 arc_ps2_inhibit_ports(arc_ps2);
212
213 error = devm_request_irq(&pdev->dev, irq, arc_ps2_interrupt,
214 0, "arc_ps2", arc_ps2);
215 if (error) {
216 dev_err(&pdev->dev, "Could not allocate IRQ\n");
217 return error;
218 }
219
220 for (i = 0; i < ARC_PS2_PORTS; i++) {
221 error = arc_ps2_create_port(pdev, arc_ps2, i);
222 if (error) {
223 while (--i >= 0)
224 serio_unregister_port(arc_ps2->port[i].io);
225 return error;
226 }
227 }
228
229 platform_set_drvdata(pdev, arc_ps2);
230
231 return 0;
232}
233
234static void arc_ps2_remove(struct platform_device *pdev)
235{
236 struct arc_ps2_data *arc_ps2 = platform_get_drvdata(pdev);
237 int i;
238
239 for (i = 0; i < ARC_PS2_PORTS; i++)
240 serio_unregister_port(arc_ps2->port[i].io);
241
242 dev_dbg(&pdev->dev, "interrupt count = %i\n", arc_ps2->total_int);
243 dev_dbg(&pdev->dev, "frame error count = %i\n", arc_ps2->frame_error);
244 dev_dbg(&pdev->dev, "buffer overflow count = %i\n",
245 arc_ps2->buf_overflow);
246}
247
248#ifdef CONFIG_OF
249static const struct of_device_id arc_ps2_match[] = {
250 { .compatible = "snps,arc_ps2" },
251 { },
252};
253MODULE_DEVICE_TABLE(of, arc_ps2_match);
254#endif
255
256static struct platform_driver arc_ps2_driver = {
257 .driver = {
258 .name = "arc_ps2",
259 .of_match_table = of_match_ptr(arc_ps2_match),
260 },
261 .probe = arc_ps2_probe,
262 .remove = arc_ps2_remove,
263};
264
265module_platform_driver(arc_ps2_driver);
266
267MODULE_LICENSE("GPL");
268MODULE_AUTHOR("Pavel Sokolov <[email protected]>");
269MODULE_DESCRIPTION("ARC PS/2 Driver");