1// SPDX-License-Identifier: GPL-2.0-only
2/* Low-level parallel port routines for the Amiga built-in port
3 *
4 * Author: Joerg Dorchain <joerg@dorchain.net>
5 *
6 * This is a complete rewrite of the code, but based heaviy upon the old
7 * lp_intern. code.
8 *
9 * The built-in Amiga parallel port provides one port at a fixed address
10 * with 8 bidirectional data lines (D0 - D7) and 3 bidirectional status
11 * lines (BUSY, POUT, SEL), 1 output control line /STROBE (raised automatically
12 * in hardware when the data register is accessed), and 1 input control line
13 * /ACK, able to cause an interrupt, but both not directly settable by
14 * software.
15 */
16
17#include <linux/module.h>
18#include <linux/init.h>
19#include <linux/parport.h>
20#include <linux/ioport.h>
21#include <linux/interrupt.h>
22#include <linux/platform_device.h>
23
24#include <asm/setup.h>
25#include <asm/amigahw.h>
26#include <asm/irq.h>
27#include <asm/io.h>
28#include <asm/amigaints.h>
29
30#undef DEBUG
31
32static void amiga_write_data(struct parport *p, unsigned char data)
33{
34	pr_debug("write_data %c\n", data);
35	/* Triggers also /STROBE. This behavior cannot be changed */
36	ciaa.prb = data;
37	mb();
38}
39
40static unsigned char amiga_read_data(struct parport *p)
41{
42	/* Triggers also /STROBE. This behavior cannot be changed */
43	return ciaa.prb;
44}
45
46static unsigned char control_amiga_to_pc(unsigned char control)
47{
48	return PARPORT_CONTROL_SELECT |
49	      PARPORT_CONTROL_AUTOFD | PARPORT_CONTROL_STROBE;
50	/* fake value: interrupt enable, select in, no reset,
51	no autolf, no strobe - seems to be closest the wiring diagram */
52}
53
54static void amiga_write_control(struct parport *p, unsigned char control)
55{
56	pr_debug("write_control %02x\n", control);
57	/* No implementation possible */
58}
59
60static unsigned char amiga_read_control( struct parport *p)
61{
62	pr_debug("read_control\n");
63	return control_amiga_to_pc(0);
64}
65
66static unsigned char amiga_frob_control( struct parport *p, unsigned char mask, unsigned char val)
67{
68	unsigned char old;
69
70	pr_debug("frob_control mask %02x, value %02x\n", mask, val);
71	old = amiga_read_control(p);
72	amiga_write_control(p, (old & ~mask) ^ val);
73	return old;
74}
75
76static unsigned char status_amiga_to_pc(unsigned char status)
77{
78	unsigned char ret = PARPORT_STATUS_BUSY | PARPORT_STATUS_ACK | PARPORT_STATUS_ERROR;
79
80	if (status & 1) /* Busy */
81		ret &= ~PARPORT_STATUS_BUSY;
82	if (status & 2) /* PaperOut */
83		ret |= PARPORT_STATUS_PAPEROUT;
84	if (status & 4) /* Selected */
85		ret |= PARPORT_STATUS_SELECT;
86	/* the rest is not connected or handled autonomously in hardware */
87
88	return ret;
89}
90
91static unsigned char amiga_read_status(struct parport *p)
92{
93	unsigned char status;
94
95	status = status_amiga_to_pc(ciab.pra & 7);
96	pr_debug("read_status %02x\n", status);
97	return status;
98}
99
100static void amiga_enable_irq(struct parport *p)
101{
102	enable_irq(IRQ_AMIGA_CIAA_FLG);
103}
104
105static void amiga_disable_irq(struct parport *p)
106{
107	disable_irq(IRQ_AMIGA_CIAA_FLG);
108}
109
110static void amiga_data_forward(struct parport *p)
111{
112	pr_debug("forward\n");
113	ciaa.ddrb = 0xff; /* all pins output */
114	mb();
115}
116
117static void amiga_data_reverse(struct parport *p)
118{
119	pr_debug("reverse\n");
120	ciaa.ddrb = 0; /* all pins input */
121	mb();
122}
123
124static void amiga_init_state(struct pardevice *dev, struct parport_state *s)
125{
126	s->u.amiga.data = 0;
127	s->u.amiga.datadir = 255;
128	s->u.amiga.status = 0;
129	s->u.amiga.statusdir = 0;
130}
131
132static void amiga_save_state(struct parport *p, struct parport_state *s)
133{
134	mb();
135	s->u.amiga.data = ciaa.prb;
136	s->u.amiga.datadir = ciaa.ddrb;
137	s->u.amiga.status = ciab.pra & 7;
138	s->u.amiga.statusdir = ciab.ddra & 7;
139	mb();
140}
141
142static void amiga_restore_state(struct parport *p, struct parport_state *s)
143{
144	mb();
145	ciaa.prb = s->u.amiga.data;
146	ciaa.ddrb = s->u.amiga.datadir;
147	ciab.pra |= (ciab.pra & 0xf8) | s->u.amiga.status;
148	ciab.ddra |= (ciab.ddra & 0xf8) | s->u.amiga.statusdir;
149	mb();
150}
151
152static struct parport_operations pp_amiga_ops = {
153	.write_data	= amiga_write_data,
154	.read_data	= amiga_read_data,
155
156	.write_control	= amiga_write_control,
157	.read_control	= amiga_read_control,
158	.frob_control	= amiga_frob_control,
159
160	.read_status	= amiga_read_status,
161
162	.enable_irq	= amiga_enable_irq,
163	.disable_irq	= amiga_disable_irq,
164
165	.data_forward	= amiga_data_forward,
166	.data_reverse	= amiga_data_reverse,
167
168	.init_state	= amiga_init_state,
169	.save_state	= amiga_save_state,
170	.restore_state	= amiga_restore_state,
171
172	.epp_write_data	= parport_ieee1284_epp_write_data,
173	.epp_read_data	= parport_ieee1284_epp_read_data,
174	.epp_write_addr	= parport_ieee1284_epp_write_addr,
175	.epp_read_addr	= parport_ieee1284_epp_read_addr,
176
177	.ecp_write_data	= parport_ieee1284_ecp_write_data,
178	.ecp_read_data	= parport_ieee1284_ecp_read_data,
179	.ecp_write_addr	= parport_ieee1284_ecp_write_addr,
180
181	.compat_write_data	= parport_ieee1284_write_compat,
182	.nibble_read_data	= parport_ieee1284_read_nibble,
183	.byte_read_data		= parport_ieee1284_read_byte,
184
185	.owner		= THIS_MODULE,
186};
187
188/* ----------- Initialisation code --------------------------------- */
189
190static int __init amiga_parallel_probe(struct platform_device *pdev)
191{
192	struct parport *p;
193	int err;
194
195	ciaa.ddrb = 0xff;
196	ciab.ddra &= 0xf8;
197	mb();
198
199	p = parport_register_port((unsigned long)&ciaa.prb, IRQ_AMIGA_CIAA_FLG,
200				   PARPORT_DMA_NONE, &pp_amiga_ops);
201	if (!p)
202		return -EBUSY;
203
204	err = request_irq(IRQ_AMIGA_CIAA_FLG, parport_irq_handler, 0, p->name,
205			  p);
206	if (err)
207		goto out_irq;
208
209	pr_info("%s: Amiga built-in port using irq\n", p->name);
210	/* XXX: set operating mode */
211	parport_announce_port(p);
212
213	platform_set_drvdata(pdev, p);
214
215	return 0;
216
217out_irq:
218	parport_put_port(p);
219	return err;
220}
221
222static void __exit amiga_parallel_remove(struct platform_device *pdev)
223{
224	struct parport *port = platform_get_drvdata(pdev);
225
226	parport_remove_port(port);
227	if (port->irq != PARPORT_IRQ_NONE)
228		free_irq(IRQ_AMIGA_CIAA_FLG, port);
229	parport_put_port(port);
230}
231
232static struct platform_driver amiga_parallel_driver = {
233	.remove_new = __exit_p(amiga_parallel_remove),
234	.driver   = {
235		.name	= "amiga-parallel",
236	},
237};
238
239module_platform_driver_probe(amiga_parallel_driver, amiga_parallel_probe);
240
241MODULE_AUTHOR("Joerg Dorchain <joerg@dorchain.net>");
242MODULE_DESCRIPTION("Parport Driver for Amiga builtin Port");
243MODULE_LICENSE("GPL");
244MODULE_ALIAS("platform:amiga-parallel");
245