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(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(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
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(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
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(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_new = 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