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 
32 static 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 
40 static unsigned char amiga_read_data(struct parport *p)
41 {
42 	/* Triggers also /STROBE. This behavior cannot be changed */
43 	return ciaa.prb;
44 }
45 
46 static 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 
54 static 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 
60 static unsigned char amiga_read_control( struct parport *p)
61 {
62 	pr_debug("read_control\n");
63 	return control_amiga_to_pc(0);
64 }
65 
66 static 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 
76 static 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 
91 static 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 
100 static void amiga_enable_irq(struct parport *p)
101 {
102 	enable_irq(IRQ_AMIGA_CIAA_FLG);
103 }
104 
105 static void amiga_disable_irq(struct parport *p)
106 {
107 	disable_irq(IRQ_AMIGA_CIAA_FLG);
108 }
109 
110 static void amiga_data_forward(struct parport *p)
111 {
112 	pr_debug("forward\n");
113 	ciaa.ddrb = 0xff; /* all pins output */
114 	mb();
115 }
116 
117 static void amiga_data_reverse(struct parport *p)
118 {
119 	pr_debug("reverse\n");
120 	ciaa.ddrb = 0; /* all pins input */
121 	mb();
122 }
123 
124 static 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 
132 static 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 
142 static 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 
152 static 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 
190 static 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 
217 out_irq:
218 	parport_put_port(p);
219 	return err;
220 }
221 
222 static int __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 	return 0;
231 }
232 
233 static struct platform_driver amiga_parallel_driver = {
234 	.remove = __exit_p(amiga_parallel_remove),
235 	.driver   = {
236 		.name	= "amiga-parallel",
237 	},
238 };
239 
240 module_platform_driver_probe(amiga_parallel_driver, amiga_parallel_probe);
241 
242 MODULE_AUTHOR("Joerg Dorchain <joerg@dorchain.net>");
243 MODULE_DESCRIPTION("Parport Driver for Amiga builtin Port");
244 MODULE_SUPPORTED_DEVICE("Amiga builtin Parallel Port");
245 MODULE_LICENSE("GPL");
246 MODULE_ALIAS("platform:amiga-parallel");
247