1// SPDX-License-Identifier: GPL-2.0-only
2/* Low-level parallel port routines for the Atari builtin port
3 *
4 * Author: Andreas Schwab <schwab@issan.informatik.uni-dortmund.de>
5 *
6 * Based on parport_amiga.c.
7 *
8 * The built-in Atari parallel port provides one port at a fixed address
9 * with 8 output data lines (D0 - D7), 1 output control line (STROBE)
10 * and 1 input status line (BUSY) able to cause an interrupt.
11 */
12
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/parport.h>
16#include <linux/interrupt.h>
17#include <asm/setup.h>
18#include <asm/atarihw.h>
19#include <asm/irq.h>
20#include <asm/atariints.h>
21
22static struct parport *this_port;
23
24static unsigned char
25parport_atari_read_data(struct parport *p)
26{
27	unsigned long flags;
28	unsigned char data;
29
30	local_irq_save(flags);
31	sound_ym.rd_data_reg_sel = 15;
32	data = sound_ym.rd_data_reg_sel;
33	local_irq_restore(flags);
34	return data;
35}
36
37static void
38parport_atari_write_data(struct parport *p, unsigned char data)
39{
40	unsigned long flags;
41
42	local_irq_save(flags);
43	sound_ym.rd_data_reg_sel = 15;
44	sound_ym.wd_data = data;
45	local_irq_restore(flags);
46}
47
48static unsigned char
49parport_atari_read_control(struct parport *p)
50{
51	unsigned long flags;
52	unsigned char control = 0;
53
54	local_irq_save(flags);
55	sound_ym.rd_data_reg_sel = 14;
56	if (!(sound_ym.rd_data_reg_sel & (1 << 5)))
57		control = PARPORT_CONTROL_STROBE;
58	local_irq_restore(flags);
59	return control;
60}
61
62static void
63parport_atari_write_control(struct parport *p, unsigned char control)
64{
65	unsigned long flags;
66
67	local_irq_save(flags);
68	sound_ym.rd_data_reg_sel = 14;
69	if (control & PARPORT_CONTROL_STROBE)
70		sound_ym.wd_data = sound_ym.rd_data_reg_sel & ~(1 << 5);
71	else
72		sound_ym.wd_data = sound_ym.rd_data_reg_sel | (1 << 5);
73	local_irq_restore(flags);
74}
75
76static unsigned char
77parport_atari_frob_control(struct parport *p, unsigned char mask,
78			   unsigned char val)
79{
80	unsigned char old = parport_atari_read_control(p);
81	parport_atari_write_control(p, (old & ~mask) ^ val);
82	return old;
83}
84
85static unsigned char
86parport_atari_read_status(struct parport *p)
87{
88	return ((st_mfp.par_dt_reg & 1 ? 0 : PARPORT_STATUS_BUSY) |
89		PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR);
90}
91
92static void
93parport_atari_init_state(struct pardevice *d, struct parport_state *s)
94{
95}
96
97static void
98parport_atari_save_state(struct parport *p, struct parport_state *s)
99{
100}
101
102static void
103parport_atari_restore_state(struct parport *p, struct parport_state *s)
104{
105}
106
107static void
108parport_atari_enable_irq(struct parport *p)
109{
110	enable_irq(IRQ_MFP_BUSY);
111}
112
113static void
114parport_atari_disable_irq(struct parport *p)
115{
116	disable_irq(IRQ_MFP_BUSY);
117}
118
119static void
120parport_atari_data_forward(struct parport *p)
121{
122	unsigned long flags;
123
124	local_irq_save(flags);
125	/* Soundchip port B as output. */
126	sound_ym.rd_data_reg_sel = 7;
127	sound_ym.wd_data = sound_ym.rd_data_reg_sel | 0x40;
128	local_irq_restore(flags);
129}
130
131static void
132parport_atari_data_reverse(struct parport *p)
133{
134}
135
136static struct parport_operations parport_atari_ops = {
137	.write_data	= parport_atari_write_data,
138	.read_data	= parport_atari_read_data,
139
140	.write_control	= parport_atari_write_control,
141	.read_control	= parport_atari_read_control,
142	.frob_control	= parport_atari_frob_control,
143
144	.read_status	= parport_atari_read_status,
145
146	.enable_irq	= parport_atari_enable_irq,
147	.disable_irq	= parport_atari_disable_irq,
148
149	.data_forward	= parport_atari_data_forward,
150	.data_reverse	= parport_atari_data_reverse,
151
152	.init_state	= parport_atari_init_state,
153	.save_state	= parport_atari_save_state,
154	.restore_state	= parport_atari_restore_state,
155
156	.epp_write_data	= parport_ieee1284_epp_write_data,
157	.epp_read_data	= parport_ieee1284_epp_read_data,
158	.epp_write_addr	= parport_ieee1284_epp_write_addr,
159	.epp_read_addr	= parport_ieee1284_epp_read_addr,
160
161	.ecp_write_data	= parport_ieee1284_ecp_write_data,
162	.ecp_read_data	= parport_ieee1284_ecp_read_data,
163	.ecp_write_addr	= parport_ieee1284_ecp_write_addr,
164
165	.compat_write_data	= parport_ieee1284_write_compat,
166	.nibble_read_data	= parport_ieee1284_read_nibble,
167	.byte_read_data		= parport_ieee1284_read_byte,
168
169	.owner		= THIS_MODULE,
170};
171
172
173static int __init parport_atari_init(void)
174{
175	struct parport *p;
176	unsigned long flags;
177
178	if (MACH_IS_ATARI) {
179		local_irq_save(flags);
180		/* Soundchip port A/B as output. */
181		sound_ym.rd_data_reg_sel = 7;
182		sound_ym.wd_data = (sound_ym.rd_data_reg_sel & 0x3f) | 0xc0;
183		/* STROBE high. */
184		sound_ym.rd_data_reg_sel = 14;
185		sound_ym.wd_data = sound_ym.rd_data_reg_sel | (1 << 5);
186		local_irq_restore(flags);
187		/* MFP port I0 as input. */
188		st_mfp.data_dir &= ~1;
189		/* MFP port I0 interrupt on high->low edge. */
190		st_mfp.active_edge &= ~1;
191		p = parport_register_port((unsigned long)&sound_ym.wd_data,
192					  IRQ_MFP_BUSY, PARPORT_DMA_NONE,
193					  &parport_atari_ops);
194		if (!p)
195			return -ENODEV;
196		if (request_irq(IRQ_MFP_BUSY, parport_irq_handler, 0, p->name,
197				p)) {
198			parport_put_port (p);
199			return -ENODEV;
200		}
201
202		this_port = p;
203		pr_info("%s: Atari built-in port using irq\n", p->name);
204		parport_announce_port (p);
205
206		return 0;
207	}
208	return -ENODEV;
209}
210
211static void __exit parport_atari_exit(void)
212{
213	parport_remove_port(this_port);
214	if (this_port->irq != PARPORT_IRQ_NONE)
215		free_irq(IRQ_MFP_BUSY, this_port);
216	parport_put_port(this_port);
217}
218
219MODULE_AUTHOR("Andreas Schwab");
220MODULE_DESCRIPTION("Parport Driver for Atari builtin Port");
221MODULE_LICENSE("GPL");
222
223module_init(parport_atari_init)
224module_exit(parport_atari_exit)
225