1// SPDX-License-Identifier: GPL-2.0
2#include <linux/interrupt.h>
3#include <linux/ioport.h>
4
5#include "spk_types.h"
6#include "speakup.h"
7#include "spk_priv.h"
8#include "serialio.h"
9
10#include <linux/serial_core.h>
11/* WARNING: Do not change this to <linux/serial.h> without testing that
12 * SERIAL_PORT_DFNS does get defined to the appropriate value.
13 */
14#include <asm/serial.h>
15
16#ifndef SERIAL_PORT_DFNS
17#define SERIAL_PORT_DFNS
18#endif
19
20static void start_serial_interrupt(int irq);
21
22static const struct old_serial_port rs_table[] = {
23 SERIAL_PORT_DFNS
24};
25
26static const struct old_serial_port *serstate;
27static int timeouts;
28
29static int spk_serial_out(struct spk_synth *in_synth, const char ch);
30static void spk_serial_send_xchar(char ch);
31static void spk_serial_tiocmset(unsigned int set, unsigned int clear);
32static unsigned char spk_serial_in(void);
33static unsigned char spk_serial_in_nowait(void);
34static void spk_serial_flush_buffer(void);
35
36struct spk_io_ops spk_serial_io_ops = {
37 .synth_out = spk_serial_out,
38 .send_xchar = spk_serial_send_xchar,
39 .tiocmset = spk_serial_tiocmset,
40 .synth_in = spk_serial_in,
41 .synth_in_nowait = spk_serial_in_nowait,
42 .flush_buffer = spk_serial_flush_buffer,
43};
44EXPORT_SYMBOL_GPL(spk_serial_io_ops);
45
46const struct old_serial_port *spk_serial_init(int index)
47{
48 int baud = 9600, quot = 0;
49 unsigned int cval = 0;
50 int cflag = CREAD | HUPCL | CLOCAL | B9600 | CS8;
51 const struct old_serial_port *ser;
52 int err;
53
54 if (index >= ARRAY_SIZE(rs_table)) {
55 pr_info("no port info for ttyS%d\n", index);
56 return NULL;
57 }
58 ser = rs_table + index;
59
60 /* Divisor, bytesize and parity */
61 quot = ser->baud_base / baud;
62 cval = cflag & (CSIZE | CSTOPB);
63#if defined(__powerpc__) || defined(__alpha__)
64 cval >>= 8;
65#else /* !__powerpc__ && !__alpha__ */
66 cval >>= 4;
67#endif /* !__powerpc__ && !__alpha__ */
68 if (cflag & PARENB)
69 cval |= UART_LCR_PARITY;
70 if (!(cflag & PARODD))
71 cval |= UART_LCR_EPAR;
72 if (synth_request_region(ser->port, 8)) {
73 /* try to take it back. */
74 pr_info("Ports not available, trying to steal them\n");
75 __release_region(&ioport_resource, ser->port, 8);
76 err = synth_request_region(ser->port, 8);
77 if (err) {
78 pr_warn("Unable to allocate port at %x, errno %i",
79 ser->port, err);
80 return NULL;
81 }
82 }
83
84 /* Disable UART interrupts, set DTR and RTS high
85 * and set speed.
86 */
87 outb(cval | UART_LCR_DLAB, ser->port + UART_LCR); /* set DLAB */
88 outb(quot & 0xff, ser->port + UART_DLL); /* LS of divisor */
89 outb(quot >> 8, ser->port + UART_DLM); /* MS of divisor */
90 outb(cval, ser->port + UART_LCR); /* reset DLAB */
91
92 /* Turn off Interrupts */
93 outb(0, ser->port + UART_IER);
94 outb(UART_MCR_DTR | UART_MCR_RTS, ser->port + UART_MCR);
95
96 /* If we read 0xff from the LSR, there is no UART here. */
97 if (inb(ser->port + UART_LSR) == 0xff) {
98 synth_release_region(ser->port, 8);
99 serstate = NULL;
100 return NULL;
101 }
102
103 mdelay(1);
104 speakup_info.port_tts = ser->port;
105 serstate = ser;
106
107 start_serial_interrupt(ser->irq);
108
109 return ser;
110}
111
112static irqreturn_t synth_readbuf_handler(int irq, void *dev_id)
113{
114 unsigned long flags;
115 int c;
116
117 spin_lock_irqsave(&speakup_info.spinlock, flags);
118 while (inb_p(speakup_info.port_tts + UART_LSR) & UART_LSR_DR) {
119 c = inb_p(speakup_info.port_tts + UART_RX);
120 synth->read_buff_add((u_char)c);
121 }
122 spin_unlock_irqrestore(&speakup_info.spinlock, flags);
123 return IRQ_HANDLED;
124}
125
126static void start_serial_interrupt(int irq)
127{
128 int rv;
129
130 if (!synth->read_buff_add)
131 return;
132
133 rv = request_irq(irq, synth_readbuf_handler, IRQF_SHARED,
134 "serial", (void *)synth_readbuf_handler);
135
136 if (rv)
137 pr_err("Unable to request Speakup serial I R Q\n");
138 /* Set MCR */
139 outb(UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2,
140 speakup_info.port_tts + UART_MCR);
141 /* Turn on Interrupts */
142 outb(UART_IER_MSI | UART_IER_RLSI | UART_IER_RDI,
143 speakup_info.port_tts + UART_IER);
144 inb(speakup_info.port_tts + UART_LSR);
145 inb(speakup_info.port_tts + UART_RX);
146 inb(speakup_info.port_tts + UART_IIR);
147 inb(speakup_info.port_tts + UART_MSR);
148 outb(1, speakup_info.port_tts + UART_FCR); /* Turn FIFO On */
149}
150
151static void spk_serial_send_xchar(char ch)
152{
153 int timeout = SPK_XMITR_TIMEOUT;
154
155 while (spk_serial_tx_busy()) {
156 if (!--timeout)
157 break;
158 udelay(1);
159 }
160 outb(ch, speakup_info.port_tts);
161}
162
163static void spk_serial_tiocmset(unsigned int set, unsigned int clear)
164{
165 int old = inb(speakup_info.port_tts + UART_MCR);
166
167 outb((old & ~clear) | set, speakup_info.port_tts + UART_MCR);
168}
169
170int spk_serial_synth_probe(struct spk_synth *synth)
171{
172 const struct old_serial_port *ser;
173 int failed = 0;
174
175 if ((synth->ser >= SPK_LO_TTY) && (synth->ser <= SPK_HI_TTY)) {
176 ser = spk_serial_init(synth->ser);
177 if (!ser) {
178 failed = -1;
179 } else {
180 outb_p(0, ser->port);
181 mdelay(1);
182 outb_p('\r', ser->port);
183 }
184 } else {
185 failed = -1;
186 pr_warn("ttyS%i is an invalid port\n", synth->ser);
187 }
188 if (failed) {
189 pr_info("%s: not found\n", synth->long_name);
190 return -ENODEV;
191 }
192 pr_info("%s: ttyS%i, Driver Version %s\n",
193 synth->long_name, synth->ser, synth->version);
194 synth->alive = 1;
195 return 0;
196}
197EXPORT_SYMBOL_GPL(spk_serial_synth_probe);
198
199void spk_stop_serial_interrupt(void)
200{
201 if (speakup_info.port_tts == 0)
202 return;
203
204 if (!synth->read_buff_add)
205 return;
206
207 /* Turn off interrupts */
208 outb(0, speakup_info.port_tts + UART_IER);
209 /* Free IRQ */
210 free_irq(serstate->irq, (void *)synth_readbuf_handler);
211}
212EXPORT_SYMBOL_GPL(spk_stop_serial_interrupt);
213
214int spk_wait_for_xmitr(struct spk_synth *in_synth)
215{
216 int tmout = SPK_XMITR_TIMEOUT;
217
218 if ((in_synth->alive) && (timeouts >= NUM_DISABLE_TIMEOUTS)) {
219 pr_warn("%s: too many timeouts, deactivating speakup\n",
220 in_synth->long_name);
221 in_synth->alive = 0;
222 /* No synth any more, so nobody will restart TTYs, and we thus
223 * need to do it ourselves. Now that there is no synth we can
224 * let application flood anyway
225 */
226 speakup_start_ttys();
227 timeouts = 0;
228 return 0;
229 }
230 while (spk_serial_tx_busy()) {
231 if (--tmout == 0) {
232 pr_warn("%s: timed out (tx busy)\n",
233 in_synth->long_name);
234 timeouts++;
235 return 0;
236 }
237 udelay(1);
238 }
239 tmout = SPK_CTS_TIMEOUT;
240 while (!((inb_p(speakup_info.port_tts + UART_MSR)) & UART_MSR_CTS)) {
241 /* CTS */
242 if (--tmout == 0) {
243 timeouts++;
244 return 0;
245 }
246 udelay(1);
247 }
248 timeouts = 0;
249 return 1;
250}
251
252static unsigned char spk_serial_in(void)
253{
254 int tmout = SPK_SERIAL_TIMEOUT;
255
256 while (!(inb_p(speakup_info.port_tts + UART_LSR) & UART_LSR_DR)) {
257 if (--tmout == 0) {
258 pr_warn("time out while waiting for input.\n");
259 return 0xff;
260 }
261 udelay(1);
262 }
263 return inb_p(speakup_info.port_tts + UART_RX);
264}
265
266static unsigned char spk_serial_in_nowait(void)
267{
268 unsigned char lsr;
269
270 lsr = inb_p(speakup_info.port_tts + UART_LSR);
271 if (!(lsr & UART_LSR_DR))
272 return 0;
273 return inb_p(speakup_info.port_tts + UART_RX);
274}
275
276static void spk_serial_flush_buffer(void)
277{
278 /* TODO: flush the UART 16550 buffer */
279}
280
281static int spk_serial_out(struct spk_synth *in_synth, const char ch)
282{
283 if (in_synth->alive && spk_wait_for_xmitr(in_synth)) {
284 outb_p(ch, speakup_info.port_tts);
285 return 1;
286 }
287 return 0;
288}
289
290const char *spk_serial_synth_immediate(struct spk_synth *synth,
291 const char *buff)
292{
293 u_char ch;
294
295 while ((ch = *buff)) {
296 if (ch == '\n')
297 ch = synth->procspeech;
298 if (spk_wait_for_xmitr(synth))
299 outb(ch, speakup_info.port_tts);
300 else
301 return buff;
302 buff++;
303 }
304 return NULL;
305}
306EXPORT_SYMBOL_GPL(spk_serial_synth_immediate);
307
308void spk_serial_release(void)
309{
310 spk_stop_serial_interrupt();
311 if (speakup_info.port_tts == 0)
312 return;
313 synth_release_region(speakup_info.port_tts, 8);
314 speakup_info.port_tts = 0;
315}
316EXPORT_SYMBOL_GPL(spk_serial_release);
317