1/* $NetBSD: uart.c,v 1.2 2007/03/23 20:05:47 dogcow Exp $ */
2
3/*-
4 * Copyright (c) 2007 Ruslan Ermilov and Vsevolod Lobko.
5 * Copyright (c) 2007 Oleksandr Tymoshenko.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or
9 * without modification, are permitted provided that the following
10 * conditions are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above
14 *    copyright notice, this list of conditions and the following
15 *    disclaimer in the documentation and/or other materials provided
16 *    with the distribution.
17 * 3. The names of the authors may not be used to endorse or promote
18 *    products derived from this software without specific prior
19 *    written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY
22 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
23 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
24 * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS
25 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
26 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
27 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
28 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
30 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
32 * OF SUCH DAMAGE.
33 */
34
35#include <sys/cdefs.h>
36__FBSDID("$FreeBSD$");
37
38#include <sys/param.h>
39#include <sys/systm.h>
40#include <sys/bus.h>
41#include <sys/conf.h>
42#include <machine/bus.h>
43
44#include <dev/uart/uart.h>
45#include <dev/uart/uart_cpu.h>
46#include <dev/uart/uart_bus.h>
47
48#include <mips/adm5120/uart_dev_adm5120.h>
49
50#include "uart_if.h"
51
52/*
53 * Low-level UART interface.
54 */
55static int adm5120_uart_probe(struct uart_bas *bas);
56static void adm5120_uart_init(struct uart_bas *bas, int, int, int, int);
57static void adm5120_uart_term(struct uart_bas *bas);
58static void adm5120_uart_putc(struct uart_bas *bas, int);
59static int adm5120_uart_rxready(struct uart_bas *bas);
60static int adm5120_uart_getc(struct uart_bas *bas, struct mtx *);
61
62static struct uart_ops uart_adm5120_uart_ops = {
63	.probe = adm5120_uart_probe,
64	.init = adm5120_uart_init,
65	.term = adm5120_uart_term,
66	.putc = adm5120_uart_putc,
67	.rxready = adm5120_uart_rxready,
68	.getc = adm5120_uart_getc,
69};
70
71static int
72adm5120_uart_probe(struct uart_bas *bas)
73{
74
75	return (0);
76}
77
78static void
79adm5120_uart_init(struct uart_bas *bas, int baudrate, int databits,
80    int stopbits, int parity)
81{
82
83	/* TODO: Set parameters for uart, meanwhile stick with 115200N1 */
84}
85
86static void
87adm5120_uart_term(struct uart_bas *bas)
88{
89
90}
91
92static void
93adm5120_uart_putc(struct uart_bas *bas, int c)
94{
95	char chr;
96	chr = c;
97	while (uart_getreg(bas, UART_FR_REG) & UART_FR_TX_FIFO_FULL)
98		;
99	uart_setreg(bas, UART_DR_REG, c);
100	while (uart_getreg(bas, UART_FR_REG) & UART_FR_BUSY)
101		;
102	uart_barrier(bas);
103}
104
105static int
106adm5120_uart_rxready(struct uart_bas *bas)
107{
108	if (uart_getreg(bas, UART_FR_REG) & UART_FR_RX_FIFO_EMPTY)
109		return (0);
110
111	return (1);
112}
113
114static int
115adm5120_uart_getc(struct uart_bas *bas, struct mtx *hwmtx)
116{
117	int c;
118
119	uart_lock(hwmtx);
120
121	while (uart_getreg(bas, UART_FR_REG) & UART_FR_RX_FIFO_EMPTY) {
122		uart_unlock(hwmtx);
123		DELAY(10);
124		uart_lock(hwmtx);
125	}
126
127	c = uart_getreg(bas, UART_DR_REG);
128
129	uart_unlock(hwmtx);
130
131	return (c);
132}
133
134/*
135 * High-level UART interface.
136 */
137struct adm5120_uart_softc {
138	struct uart_softc base;
139};
140
141static int adm5120_uart_bus_attach(struct uart_softc *);
142static int adm5120_uart_bus_detach(struct uart_softc *);
143static int adm5120_uart_bus_flush(struct uart_softc *, int);
144static int adm5120_uart_bus_getsig(struct uart_softc *);
145static int adm5120_uart_bus_ioctl(struct uart_softc *, int, intptr_t);
146static int adm5120_uart_bus_ipend(struct uart_softc *);
147static int adm5120_uart_bus_param(struct uart_softc *, int, int, int, int);
148static int adm5120_uart_bus_probe(struct uart_softc *);
149static int adm5120_uart_bus_receive(struct uart_softc *);
150static int adm5120_uart_bus_setsig(struct uart_softc *, int);
151static int adm5120_uart_bus_transmit(struct uart_softc *);
152
153static kobj_method_t adm5120_uart_methods[] = {
154	KOBJMETHOD(uart_attach,		adm5120_uart_bus_attach),
155	KOBJMETHOD(uart_detach,		adm5120_uart_bus_detach),
156	KOBJMETHOD(uart_flush,		adm5120_uart_bus_flush),
157	KOBJMETHOD(uart_getsig,		adm5120_uart_bus_getsig),
158	KOBJMETHOD(uart_ioctl,		adm5120_uart_bus_ioctl),
159	KOBJMETHOD(uart_ipend,		adm5120_uart_bus_ipend),
160	KOBJMETHOD(uart_param,		adm5120_uart_bus_param),
161	KOBJMETHOD(uart_probe,		adm5120_uart_bus_probe),
162	KOBJMETHOD(uart_receive,	adm5120_uart_bus_receive),
163	KOBJMETHOD(uart_setsig,		adm5120_uart_bus_setsig),
164	KOBJMETHOD(uart_transmit,	adm5120_uart_bus_transmit),
165	{ 0, 0 }
166};
167
168struct uart_class uart_adm5120_uart_class = {
169	"adm5120",
170	adm5120_uart_methods,
171	sizeof(struct adm5120_uart_softc),
172	.uc_ops = &uart_adm5120_uart_ops,
173	.uc_range = 1, /* use hinted range */
174	.uc_rclk = 62500000
175};
176
177#define	SIGCHG(c, i, s, d)				\
178	if (c) {					\
179		i |= (i & s) ? s : s | d;		\
180	} else {					\
181		i = (i & s) ? (i & ~s) | d : i;		\
182	}
183
184/*
185 * Disable TX interrupt. uart should be locked
186 */
187static __inline void
188adm5120_uart_disable_txintr(struct uart_softc *sc)
189{
190	uint8_t cr;
191
192	cr = uart_getreg(&sc->sc_bas, UART_CR_REG);
193	cr &= ~UART_CR_TX_INT_EN;
194	uart_setreg(&sc->sc_bas, UART_CR_REG, cr);
195}
196
197/*
198 * Enable TX interrupt. uart should be locked
199 */
200static __inline void
201adm5120_uart_enable_txintr(struct uart_softc *sc)
202{
203	uint8_t cr;
204
205	cr = uart_getreg(&sc->sc_bas, UART_CR_REG);
206	cr |= UART_CR_TX_INT_EN;
207	uart_setreg(&sc->sc_bas, UART_CR_REG, cr);
208}
209
210static int
211adm5120_uart_bus_attach(struct uart_softc *sc)
212{
213	struct uart_bas *bas;
214	struct uart_devinfo *di;
215
216	bas = &sc->sc_bas;
217	if (sc->sc_sysdev != NULL) {
218		di = sc->sc_sysdev;
219		/* TODO: set parameters from di */
220	} else {
221		/* TODO: set parameters 115200, 8N1 */
222	}
223
224	sc->sc_rxfifosz = 16;
225	sc->sc_txfifosz = 16;
226
227	(void)adm5120_uart_bus_getsig(sc);
228
229#if 1
230	/* Enable FIFO */
231	uart_setreg(bas, UART_LCR_H_REG,
232	    uart_getreg(bas, UART_LCR_H_REG) | UART_LCR_H_FEN);
233#endif
234	/* Enable interrupts */
235	uart_setreg(bas, UART_CR_REG,
236	    UART_CR_PORT_EN|UART_CR_RX_INT_EN|UART_CR_RX_TIMEOUT_INT_EN|
237	    UART_CR_MODEM_STATUS_INT_EN);
238
239	return (0);
240}
241
242static int
243adm5120_uart_bus_detach(struct uart_softc *sc)
244{
245
246	return (0);
247}
248
249static int
250adm5120_uart_bus_flush(struct uart_softc *sc, int what)
251{
252
253	return (0);
254}
255
256static int
257adm5120_uart_bus_getsig(struct uart_softc *sc)
258{
259	uint32_t new, old, sig;
260	uint8_t bes;
261
262	do {
263		old = sc->sc_hwsig;
264		sig = old;
265		uart_lock(sc->sc_hwmtx);
266		bes = uart_getreg(&sc->sc_bas, UART_FR_REG);
267		uart_unlock(sc->sc_hwmtx);
268		SIGCHG(bes & UART_FR_CTS, sig, SER_CTS, SER_DCTS);
269		SIGCHG(bes & UART_FR_DCD, sig, SER_DCD, SER_DDCD);
270		SIGCHG(bes & UART_FR_DSR, sig, SER_DSR, SER_DDSR);
271		new = sig & ~SER_MASK_DELTA;
272	} while (!atomic_cmpset_32(&sc->sc_hwsig, old, new));
273
274	return (sig);
275}
276
277static int
278adm5120_uart_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)
279{
280	struct uart_bas *bas;
281	int baudrate, divisor, error;
282
283	bas = &sc->sc_bas;
284	error = 0;
285	uart_lock(sc->sc_hwmtx);
286	switch (request) {
287	case UART_IOCTL_BREAK:
288		/* TODO: Send BREAK */
289		break;
290	case UART_IOCTL_BAUD:
291		divisor = uart_getreg(bas, UART_LCR_M_REG);
292		divisor = (divisor << 8) |
293		    uart_getreg(bas, UART_LCR_L_REG);
294		baudrate = bas->rclk / 2 / (divisor + 2);
295		*(int*)data = baudrate;
296		break;
297	default:
298		error = EINVAL;
299		break;
300	}
301	uart_unlock(sc->sc_hwmtx);
302	return (error);
303}
304
305static int
306adm5120_uart_bus_ipend(struct uart_softc *sc)
307{
308	struct uart_bas *bas;
309	int ipend;
310	uint8_t ir, fr, rsr;
311
312	bas = &sc->sc_bas;
313	ipend = 0;
314
315	uart_lock(sc->sc_hwmtx);
316	ir = uart_getreg(&sc->sc_bas, UART_IR_REG);
317	fr = uart_getreg(&sc->sc_bas, UART_FR_REG);
318	rsr = uart_getreg(&sc->sc_bas, UART_RSR_REG);
319
320	if (ir & UART_IR_RX_INT)
321		ipend |= SER_INT_RXREADY;
322
323	if (ir & UART_IR_RX_TIMEOUT_INT)
324		ipend |= SER_INT_RXREADY;
325
326	if (ir & UART_IR_MODEM_STATUS_INT)
327		ipend |= SER_INT_SIGCHG;
328
329	if (rsr & UART_RSR_BE)
330		ipend |= SER_INT_BREAK;
331
332	if (rsr & UART_RSR_OE)
333		ipend |= SER_INT_OVERRUN;
334
335	if (fr & UART_FR_TX_FIFO_EMPTY) {
336		if (ir & UART_IR_TX_INT) {
337			adm5120_uart_disable_txintr(sc);
338			ipend |= SER_INT_TXIDLE;
339		}
340	}
341
342	if (ipend)
343		uart_setreg(bas, UART_IR_REG, ir | UART_IR_UICR);
344
345	uart_unlock(sc->sc_hwmtx);
346
347	return (ipend);
348}
349
350static int
351adm5120_uart_bus_param(struct uart_softc *sc, int baudrate, int databits,
352    int stopbits, int parity)
353{
354
355	/* TODO: Set parameters for uart, meanwhile stick with 115200 8N1 */
356	return (0);
357}
358
359static int
360adm5120_uart_bus_probe(struct uart_softc *sc)
361{
362	char buf[80];
363	int error;
364	char ch;
365
366	error = adm5120_uart_probe(&sc->sc_bas);
367	if (error)
368		return (error);
369
370	ch = sc->sc_bas.chan + 'A';
371
372	snprintf(buf, sizeof(buf), "adm5120_uart, channel %c", ch);
373	device_set_desc_copy(sc->sc_dev, buf);
374
375	return (0);
376}
377
378static int
379adm5120_uart_bus_receive(struct uart_softc *sc)
380{
381	struct uart_bas *bas;
382	int xc;
383	uint8_t fr, rsr;
384
385	bas = &sc->sc_bas;
386	uart_lock(sc->sc_hwmtx);
387	fr = uart_getreg(bas, UART_FR_REG);
388	while (!(fr & UART_FR_RX_FIFO_EMPTY)) {
389		if (uart_rx_full(sc)) {
390			sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
391			break;
392		}
393		xc = 0;
394		rsr = uart_getreg(bas, UART_RSR_REG);
395		if (rsr & UART_RSR_FE)
396			xc |= UART_STAT_FRAMERR;
397		if (rsr & UART_RSR_PE)
398			xc |= UART_STAT_PARERR;
399		if (rsr & UART_RSR_OE)
400			xc |= UART_STAT_OVERRUN;
401		xc |= uart_getreg(bas, UART_DR_REG);
402		uart_barrier(bas);
403		uart_rx_put(sc, xc);
404		if (rsr & (UART_RSR_FE | UART_RSR_PE | UART_RSR_OE)) {
405			uart_setreg(bas, UART_ECR_REG, UART_ECR_RSR);
406			uart_barrier(bas);
407		}
408		fr = uart_getreg(bas, UART_FR_REG);
409	}
410
411	/* Discard everything left in the Rx FIFO. */
412	while (!(fr & UART_FR_RX_FIFO_EMPTY)) {
413		( void)uart_getreg(bas, UART_DR_REG);
414		uart_barrier(bas);
415		rsr = uart_getreg(bas, UART_RSR_REG);
416		if (rsr & (UART_RSR_FE | UART_RSR_PE | UART_RSR_OE)) {
417			uart_setreg(bas, UART_ECR_REG, UART_ECR_RSR);
418			uart_barrier(bas);
419		}
420		fr = uart_getreg(bas, UART_FR_REG);
421	}
422	uart_unlock(sc->sc_hwmtx);
423	return (0);
424}
425
426static int
427adm5120_uart_bus_setsig(struct uart_softc *sc, int sig)
428{
429
430	/* TODO: implement (?) */
431	return (0);
432}
433
434static int
435adm5120_uart_bus_transmit(struct uart_softc *sc)
436{
437	struct uart_bas *bas;
438
439	bas = &sc->sc_bas;
440	uart_lock(sc->sc_hwmtx);
441	sc->sc_txbusy = 1;
442	for (int i = 0; i < sc->sc_txdatasz; i++) {
443		if (uart_getreg(bas, UART_FR_REG) & UART_FR_TX_FIFO_FULL)
444			break;
445		uart_setreg(bas, UART_DR_REG, sc->sc_txbuf[i]);
446	}
447
448	/* Enable TX interrupt */
449	adm5120_uart_enable_txintr(sc);
450	uart_unlock(sc->sc_hwmtx);
451	return (0);
452}
453