Merge tag 'fuse-update-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mszered...
[linux-2.6-microblaze.git] / drivers / accessibility / speakup / serialio.c
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
20 static void start_serial_interrupt(int irq);
21
22 static const struct old_serial_port rs_table[] = {
23         SERIAL_PORT_DFNS
24 };
25
26 static const struct old_serial_port *serstate;
27 static int timeouts;
28
29 static int spk_serial_out(struct spk_synth *in_synth, const char ch);
30 static void spk_serial_send_xchar(char ch);
31 static void spk_serial_tiocmset(unsigned int set, unsigned int clear);
32 static unsigned char spk_serial_in(void);
33 static unsigned char spk_serial_in_nowait(void);
34 static void spk_serial_flush_buffer(void);
35 static int spk_serial_wait_for_xmitr(struct spk_synth *in_synth);
36
37 struct spk_io_ops spk_serial_io_ops = {
38         .synth_out = spk_serial_out,
39         .send_xchar = spk_serial_send_xchar,
40         .tiocmset = spk_serial_tiocmset,
41         .synth_in = spk_serial_in,
42         .synth_in_nowait = spk_serial_in_nowait,
43         .flush_buffer = spk_serial_flush_buffer,
44         .wait_for_xmitr = spk_serial_wait_for_xmitr,
45 };
46 EXPORT_SYMBOL_GPL(spk_serial_io_ops);
47
48 const struct old_serial_port *spk_serial_init(int index)
49 {
50         int baud = 9600, quot = 0;
51         unsigned int cval = 0;
52         int cflag = CREAD | HUPCL | CLOCAL | B9600 | CS8;
53         const struct old_serial_port *ser;
54         int err;
55
56         if (index >= ARRAY_SIZE(rs_table)) {
57                 pr_info("no port info for ttyS%d\n", index);
58                 return NULL;
59         }
60         ser = rs_table + index;
61
62         /*      Divisor, bytesize and parity */
63         quot = ser->baud_base / baud;
64         cval = cflag & (CSIZE | CSTOPB);
65 #if defined(__powerpc__) || defined(__alpha__)
66         cval >>= 8;
67 #else /* !__powerpc__ && !__alpha__ */
68         cval >>= 4;
69 #endif /* !__powerpc__ && !__alpha__ */
70         if (cflag & PARENB)
71                 cval |= UART_LCR_PARITY;
72         if (!(cflag & PARODD))
73                 cval |= UART_LCR_EPAR;
74         if (synth_request_region(ser->port, 8)) {
75                 /* try to take it back. */
76                 pr_info("Ports not available, trying to steal them\n");
77                 __release_region(&ioport_resource, ser->port, 8);
78                 err = synth_request_region(ser->port, 8);
79                 if (err) {
80                         pr_warn("Unable to allocate port at %x, errno %i",
81                                 ser->port, err);
82                         return NULL;
83                 }
84         }
85
86         /*      Disable UART interrupts, set DTR and RTS high
87          *      and set speed.
88          */
89         outb(cval | UART_LCR_DLAB, ser->port + UART_LCR);       /* set DLAB */
90         outb(quot & 0xff, ser->port + UART_DLL);        /* LS of divisor */
91         outb(quot >> 8, ser->port + UART_DLM);          /* MS of divisor */
92         outb(cval, ser->port + UART_LCR);               /* reset DLAB */
93
94         /* Turn off Interrupts */
95         outb(0, ser->port + UART_IER);
96         outb(UART_MCR_DTR | UART_MCR_RTS, ser->port + UART_MCR);
97
98         /* If we read 0xff from the LSR, there is no UART here. */
99         if (inb(ser->port + UART_LSR) == 0xff) {
100                 synth_release_region(ser->port, 8);
101                 serstate = NULL;
102                 return NULL;
103         }
104
105         mdelay(1);
106         speakup_info.port_tts = ser->port;
107         serstate = ser;
108
109         start_serial_interrupt(ser->irq);
110
111         return ser;
112 }
113
114 static irqreturn_t synth_readbuf_handler(int irq, void *dev_id)
115 {
116         unsigned long flags;
117         int c;
118
119         spin_lock_irqsave(&speakup_info.spinlock, flags);
120         while (inb_p(speakup_info.port_tts + UART_LSR) & UART_LSR_DR) {
121                 c = inb_p(speakup_info.port_tts + UART_RX);
122                 synth->read_buff_add((u_char)c);
123         }
124         spin_unlock_irqrestore(&speakup_info.spinlock, flags);
125         return IRQ_HANDLED;
126 }
127
128 static void start_serial_interrupt(int irq)
129 {
130         int rv;
131
132         if (!synth->read_buff_add)
133                 return;
134
135         rv = request_irq(irq, synth_readbuf_handler, IRQF_SHARED,
136                          "serial", (void *)synth_readbuf_handler);
137
138         if (rv)
139                 pr_err("Unable to request Speakup serial I R Q\n");
140         /* Set MCR */
141         outb(UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2,
142              speakup_info.port_tts + UART_MCR);
143         /* Turn on Interrupts */
144         outb(UART_IER_MSI | UART_IER_RLSI | UART_IER_RDI,
145              speakup_info.port_tts + UART_IER);
146         inb(speakup_info.port_tts + UART_LSR);
147         inb(speakup_info.port_tts + UART_RX);
148         inb(speakup_info.port_tts + UART_IIR);
149         inb(speakup_info.port_tts + UART_MSR);
150         outb(1, speakup_info.port_tts + UART_FCR);      /* Turn FIFO On */
151 }
152
153 static void spk_serial_send_xchar(char ch)
154 {
155         int timeout = SPK_XMITR_TIMEOUT;
156
157         while (spk_serial_tx_busy()) {
158                 if (!--timeout)
159                         break;
160                 udelay(1);
161         }
162         outb(ch, speakup_info.port_tts);
163 }
164
165 static void spk_serial_tiocmset(unsigned int set, unsigned int clear)
166 {
167         int old = inb(speakup_info.port_tts + UART_MCR);
168
169         outb((old & ~clear) | set, speakup_info.port_tts + UART_MCR);
170 }
171
172 int spk_serial_synth_probe(struct spk_synth *synth)
173 {
174         const struct old_serial_port *ser;
175         int failed = 0;
176
177         if ((synth->ser >= SPK_LO_TTY) && (synth->ser <= SPK_HI_TTY)) {
178                 ser = spk_serial_init(synth->ser);
179                 if (!ser) {
180                         failed = -1;
181                 } else {
182                         outb_p(0, ser->port);
183                         mdelay(1);
184                         outb_p('\r', ser->port);
185                 }
186         } else {
187                 failed = -1;
188                 pr_warn("ttyS%i is an invalid port\n", synth->ser);
189         }
190         if (failed) {
191                 pr_info("%s: not found\n", synth->long_name);
192                 return -ENODEV;
193         }
194         pr_info("%s: ttyS%i, Driver Version %s\n",
195                 synth->long_name, synth->ser, synth->version);
196         synth->alive = 1;
197         return 0;
198 }
199 EXPORT_SYMBOL_GPL(spk_serial_synth_probe);
200
201 void spk_stop_serial_interrupt(void)
202 {
203         if (speakup_info.port_tts == 0)
204                 return;
205
206         if (!synth->read_buff_add)
207                 return;
208
209         /* Turn off interrupts */
210         outb(0, speakup_info.port_tts + UART_IER);
211         /* Free IRQ */
212         free_irq(serstate->irq, (void *)synth_readbuf_handler);
213 }
214 EXPORT_SYMBOL_GPL(spk_stop_serial_interrupt);
215
216 static int spk_serial_wait_for_xmitr(struct spk_synth *in_synth)
217 {
218         int tmout = SPK_XMITR_TIMEOUT;
219
220         if ((in_synth->alive) && (timeouts >= NUM_DISABLE_TIMEOUTS)) {
221                 pr_warn("%s: too many timeouts, deactivating speakup\n",
222                         in_synth->long_name);
223                 in_synth->alive = 0;
224                 /* No synth any more, so nobody will restart TTYs, and we thus
225                  * need to do it ourselves.  Now that there is no synth we can
226                  * let application flood anyway
227                  */
228                 speakup_start_ttys();
229                 timeouts = 0;
230                 return 0;
231         }
232         while (spk_serial_tx_busy()) {
233                 if (--tmout == 0) {
234                         pr_warn("%s: timed out (tx busy)\n",
235                                 in_synth->long_name);
236                         timeouts++;
237                         return 0;
238                 }
239                 udelay(1);
240         }
241         tmout = SPK_CTS_TIMEOUT;
242         while (!((inb_p(speakup_info.port_tts + UART_MSR)) & UART_MSR_CTS)) {
243                 /* CTS */
244                 if (--tmout == 0) {
245                         timeouts++;
246                         return 0;
247                 }
248                 udelay(1);
249         }
250         timeouts = 0;
251         return 1;
252 }
253
254 static unsigned char spk_serial_in(void)
255 {
256         int tmout = SPK_SERIAL_TIMEOUT;
257
258         while (!(inb_p(speakup_info.port_tts + UART_LSR) & UART_LSR_DR)) {
259                 if (--tmout == 0) {
260                         pr_warn("time out while waiting for input.\n");
261                         return 0xff;
262                 }
263                 udelay(1);
264         }
265         return inb_p(speakup_info.port_tts + UART_RX);
266 }
267
268 static unsigned char spk_serial_in_nowait(void)
269 {
270         unsigned char lsr;
271
272         lsr = inb_p(speakup_info.port_tts + UART_LSR);
273         if (!(lsr & UART_LSR_DR))
274                 return 0;
275         return inb_p(speakup_info.port_tts + UART_RX);
276 }
277
278 static void spk_serial_flush_buffer(void)
279 {
280         /* TODO: flush the UART 16550 buffer */
281 }
282
283 static int spk_serial_out(struct spk_synth *in_synth, const char ch)
284 {
285         if (in_synth->alive && spk_serial_wait_for_xmitr(in_synth)) {
286                 outb_p(ch, speakup_info.port_tts);
287                 return 1;
288         }
289         return 0;
290 }
291
292 const char *spk_serial_synth_immediate(struct spk_synth *synth,
293                                        const char *buff)
294 {
295         u_char ch;
296
297         while ((ch = *buff)) {
298                 if (ch == '\n')
299                         ch = synth->procspeech;
300                 if (spk_serial_wait_for_xmitr(synth))
301                         outb(ch, speakup_info.port_tts);
302                 else
303                         return buff;
304                 buff++;
305         }
306         return NULL;
307 }
308 EXPORT_SYMBOL_GPL(spk_serial_synth_immediate);
309
310 void spk_serial_release(void)
311 {
312         spk_stop_serial_interrupt();
313         if (speakup_info.port_tts == 0)
314                 return;
315         synth_release_region(speakup_info.port_tts, 8);
316         speakup_info.port_tts = 0;
317 }
318 EXPORT_SYMBOL_GPL(spk_serial_release);