WebSVN – HelenOS – Diff – /branches/dynload/kernel/genarch/src/drivers/ns16550/ns16550.c


/*
 * Copyright (c) 2001-2006 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
/** @addtogroup genarch
 * @{
 */
/**
 * @file
 * @brief   NS 16550 serial port / keyboard driver.
 */
 
#include <genarch/kbd/ns16550.h>
#include <genarch/kbd/key.h>
#include <genarch/kbd/scanc.h>
#include <genarch/kbd/scanc_sun.h>
#include <arch/drivers/kbd.h>
#include <ddi/irq.h>
#include <ipc/irq.h>
#include <cpu.h>
#include <arch/asm.h>
#include <arch.h>
#include <console/chardev.h>
#include <console/console.h>
#include <interrupt.h>
#include <arch/interrupt.h>
#include <sysinfo/sysinfo.h>
#include <synch/spinlock.h>
 
#define LSR_DATA_READY  0x01
 
/** Structure representing the ns16550. */
static ns16550_t ns16550;
 
/** Structure for ns16550's IRQ. */
static irq_t ns16550_irq;
 
/*
 * These codes read from ns16550 data register are silently ignored.
 */
#define IGNORE_CODE 0x7f        /* all keys up */
 
static void ns16550_suspend(chardev_t *);
static void ns16550_resume(chardev_t *);
 
static chardev_operations_t ops = {
    .suspend = ns16550_suspend,
    .resume = ns16550_resume,
    .read = ns16550_key_read
};
 
void ns16550_interrupt(void);
 
/** Initialize keyboard and service interrupts using kernel routine */
void ns16550_grab(void)
{
    ipl_t ipl = interrupts_disable();
 
    ns16550_ier_write(&ns16550, IER_ERBFI);     /* enable receiver interrupt */
   
    while (ns16550_lsr_read(&ns16550) & LSR_DATA_READY)
        (void) ns16550_rbr_read(&ns16550);
 
    spinlock_lock(&ns16550_irq.lock);
    ns16550_irq.notif_cfg.notify = false;
    spinlock_unlock(&ns16550_irq.lock);
    interrupts_restore(ipl);
}
 
/** Resume the former interrupt vector */
void ns16550_release(void)
{
    ipl_t ipl = interrupts_disable();
    spinlock_lock(&ns16550_irq.lock);
    if (ns16550_irq.notif_cfg.answerbox)
        ns16550_irq.notif_cfg.notify = true;
    spinlock_unlock(&ns16550_irq.lock);
    interrupts_restore(ipl);
}
 
/** Initialize ns16550.
 *
 * @param devno     Device number.
 * @param port      Virtual/IO address of device's registers.
 * @param inr       Interrupt number.
 * @param cir       Clear interrupt function.
 * @param cir_arg   First argument to cir.
 */
void
ns16550_init(devno_t devno, ioport_t port, inr_t inr, cir_t cir, void *cir_arg)
{
    chardev_initialize("ns16550_kbd", &kbrd, &ops);
    stdin = &kbrd;
   
    ns16550.devno = devno;
    ns16550.io_port = port;
   
    irq_initialize(&ns16550_irq);
    ns16550_irq.devno = devno;
    ns16550_irq.inr = inr;
    ns16550_irq.claim = ns16550_claim;
    ns16550_irq.handler = ns16550_irq_handler;
    ns16550_irq.cir = cir;
    ns16550_irq.cir_arg = cir_arg;
    irq_register(&ns16550_irq);
   
    while ((ns16550_lsr_read(&ns16550) & LSR_DATA_READY))
        ns16550_rbr_read(&ns16550);
   
    sysinfo_set_item_val("kbd", NULL, true);
    sysinfo_set_item_val("kbd.type", NULL, KBD_NS16550);
    sysinfo_set_item_val("kbd.devno", NULL, devno);
    sysinfo_set_item_val("kbd.inr", NULL, inr);
    sysinfo_set_item_val("kbd.address.virtual", NULL, port);
    sysinfo_set_item_val("kbd.port", NULL, port);
   
    /* Enable interrupts */
    ns16550_ier_write(&ns16550, IER_ERBFI);
    ns16550_mcr_write(&ns16550, MCR_OUT2);
   
    uint8_t c;
    // This switches rbr & ier to mode when accept baudrate constant
    c = ns16550_lcr_read(&ns16550);
    ns16550_lcr_write(&ns16550, 0x80 | c);
    ns16550_rbr_write(&ns16550, 0x0c);
    ns16550_ier_write(&ns16550, 0x00);
    ns16550_lcr_write(&ns16550, c);
   
    ns16550_grab();
}
 
/** Process ns16550 interrupt. */
void ns16550_interrupt(void)
{
    ns16550_poll();
}
 
/* Called from getc(). */
void ns16550_resume(chardev_t *d)
{
}
 
/* Called from getc(). */
void ns16550_suspend(chardev_t *d)
{
}
 
 
char ns16550_key_read(chardev_t *d)
{
    char ch;   
 
    while(!(ch = active_read_buff_read())) {
        uint8_t x;
        while (!(ns16550_lsr_read(&ns16550) & LSR_DATA_READY));
       
        x = ns16550_rbr_read(&ns16550);
       
        if (x != IGNORE_CODE) {
            if (x & KEY_RELEASE)
                key_released(x ^ KEY_RELEASE);
            else
                active_read_key_pressed(x);
        }
    }
    return ch;
}
 
/** Poll for key press and release events.
 *
 * This function can be used to implement keyboard polling.
 */
void ns16550_poll(void)
{
    while (ns16550_lsr_read(&ns16550) & LSR_DATA_READY) {
        uint8_t x;
       
        x = ns16550_rbr_read(&ns16550);
       
        if (x != IGNORE_CODE) {
            if (x & KEY_RELEASE)
                key_released(x ^ KEY_RELEASE);
            else
                key_pressed(x);
        }
    }
}
 
irq_ownership_t ns16550_claim(void *instance)
{
    return (ns16550_lsr_read(&ns16550) & LSR_DATA_READY);
}
 
void ns16550_irq_handler(irq_t *irq)
{
    if (irq->notif_cfg.notify && irq->notif_cfg.answerbox)
        ipc_irq_send_notif(irq);
    else
        ns16550_interrupt();
}
 
/** @}
 */
 

Rev 3900	Rev 3906
1	/*	1	/*
2	* Copyright (c) 2001-2006 Jakub Jermar	2	* Copyright (c) 2001-2006 Jakub Jermar
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/** @addtogroup genarch	29	/** @addtogroup genarch
30	* @{	30	* @{
31	*/	31	*/
32	/**	32	/**
33	* @file	33	* @file
34	* @brief NS 16550 serial port / keyboard driver.	34	* @brief NS 16550 serial port / keyboard driver.
35	*/	35	*/
36		36
37	#include <genarch/kbd/ns16550.h>	37	#include <genarch/kbd/ns16550.h>
38	#include <genarch/kbd/key.h>	38	#include <genarch/kbd/key.h>
39	#include <genarch/kbd/scanc.h>	39	#include <genarch/kbd/scanc.h>
40	#include <genarch/kbd/scanc_sun.h>	40	#include <genarch/kbd/scanc_sun.h>
41	#include <arch/drivers/kbd.h>	41	#include <arch/drivers/kbd.h>
42	#include <ddi/irq.h>	42	#include <ddi/irq.h>
43	#include <ipc/irq.h>	43	#include <ipc/irq.h>
44	#include <cpu.h>	44	#include <cpu.h>
45	#include <arch/asm.h>	45	#include <arch/asm.h>
46	#include <arch.h>	46	#include <arch.h>
47	#include <console/chardev.h>	47	#include <console/chardev.h>
48	#include <console/console.h>	48	#include <console/console.h>
49	#include <interrupt.h>	49	#include <interrupt.h>
50	#include <arch/interrupt.h>	50	#include <arch/interrupt.h>
51	#include <sysinfo/sysinfo.h>	51	#include <sysinfo/sysinfo.h>
52	#include <synch/spinlock.h>	52	#include <synch/spinlock.h>
53		53
54	#define LSR_DATA_READY 0x01	54	#define LSR_DATA_READY 0x01
55		55
56	/** Structure representing the ns16550. */	56	/** Structure representing the ns16550. */
57	static ns16550_t ns16550;	57	static ns16550_t ns16550;
58		58
59	/** Structure for ns16550's IRQ. */	59	/** Structure for ns16550's IRQ. */
60	static irq_t ns16550_irq;	60	static irq_t ns16550_irq;
61		61
62	/*	62	/*
63	* These codes read from ns16550 data register are silently ignored.	63	* These codes read from ns16550 data register are silently ignored.
64	*/	64	*/
65	#define IGNORE_CODE 0x7f /* all keys up */	65	#define IGNORE_CODE 0x7f /* all keys up */
66		66
67	static void ns16550_suspend(chardev_t *);	67	static void ns16550_suspend(chardev_t *);
68	static void ns16550_resume(chardev_t *);	68	static void ns16550_resume(chardev_t *);
69		69
70	static chardev_operations_t ops = {	70	static chardev_operations_t ops = {
71	.suspend = ns16550_suspend,	71	.suspend = ns16550_suspend,
72	.resume = ns16550_resume,	72	.resume = ns16550_resume,
73	.read = ns16550_key_read	73	.read = ns16550_key_read
74	};	74	};
75		75
76	void ns16550_interrupt(void);	76	void ns16550_interrupt(void);
77		77
78	/** Initialize keyboard and service interrupts using kernel routine */	78	/** Initialize keyboard and service interrupts using kernel routine */
79	void ns16550_grab(void)	79	void ns16550_grab(void)
80	{	80	{
81	ipl_t ipl = interrupts_disable();	81	ipl_t ipl = interrupts_disable();
82		82
83	ns16550_ier_write(&ns16550, IER_ERBFI); /* enable receiver interrupt */	83	ns16550_ier_write(&ns16550, IER_ERBFI); /* enable receiver interrupt */
84		84
85	while (ns16550_lsr_read(&ns16550) & LSR_DATA_READY)	85	while (ns16550_lsr_read(&ns16550) & LSR_DATA_READY)
86	(void) ns16550_rbr_read(&ns16550);	86	(void) ns16550_rbr_read(&ns16550);
87		87
88	spinlock_lock(&ns16550_irq.lock);	88	spinlock_lock(&ns16550_irq.lock);
89	ns16550_irq.notif_cfg.notify = false;	89	ns16550_irq.notif_cfg.notify = false;
90	spinlock_unlock(&ns16550_irq.lock);	90	spinlock_unlock(&ns16550_irq.lock);
91	interrupts_restore(ipl);	91	interrupts_restore(ipl);
92	}	92	}
93		93
94	/** Resume the former interrupt vector */	94	/** Resume the former interrupt vector */
95	void ns16550_release(void)	95	void ns16550_release(void)
96	{	96	{
97	ipl_t ipl = interrupts_disable();	97	ipl_t ipl = interrupts_disable();
98	spinlock_lock(&ns16550_irq.lock);	98	spinlock_lock(&ns16550_irq.lock);
99	if (ns16550_irq.notif_cfg.answerbox)	99	if (ns16550_irq.notif_cfg.answerbox)
100	ns16550_irq.notif_cfg.notify = true;	100	ns16550_irq.notif_cfg.notify = true;
101	spinlock_unlock(&ns16550_irq.lock);	101	spinlock_unlock(&ns16550_irq.lock);
102	interrupts_restore(ipl);	102	interrupts_restore(ipl);
103	}	103	}
104		104
105	/** Initialize ns16550.	105	/** Initialize ns16550.
106	*	106	*
107	* @param devno Device number.	107	* @param devno Device number.
108	* @param port Virtual/IO address of device's registers.	108	* @param port Virtual/IO address of device's registers.
109	* @param inr Interrupt number.	109	* @param inr Interrupt number.
110	* @param cir Clear interrupt function.	110	* @param cir Clear interrupt function.
111	* @param cir_arg First argument to cir.	111	* @param cir_arg First argument to cir.
112	*/	112	*/
113	void	113	void
114	ns16550_init(devno_t devno, ioport_t port, inr_t inr, cir_t cir, void *cir_arg)	114	ns16550_init(devno_t devno, ioport_t port, inr_t inr, cir_t cir, void *cir_arg)
115	{	115	{
116	chardev_initialize("ns16550_kbd", &kbrd, &ops);	116	chardev_initialize("ns16550_kbd", &kbrd, &ops);
117	stdin = &kbrd;	117	stdin = &kbrd;
118		118
119	ns16550.devno = devno;	119	ns16550.devno = devno;
120	ns16550.io_port = port;	120	ns16550.io_port = port;
121		121
122	irq_initialize(&ns16550_irq);	122	irq_initialize(&ns16550_irq);
123	ns16550_irq.devno = devno;	123	ns16550_irq.devno = devno;
124	ns16550_irq.inr = inr;	124	ns16550_irq.inr = inr;
125	ns16550_irq.claim = ns16550_claim;	125	ns16550_irq.claim = ns16550_claim;
126	ns16550_irq.handler = ns16550_irq_handler;	126	ns16550_irq.handler = ns16550_irq_handler;
127	ns16550_irq.cir = cir;	127	ns16550_irq.cir = cir;
128	ns16550_irq.cir_arg = cir_arg;	128	ns16550_irq.cir_arg = cir_arg;
129	irq_register(&ns16550_irq);	129	irq_register(&ns16550_irq);
130		130
131	while ((ns16550_lsr_read(&ns16550) & LSR_DATA_READY))	131	while ((ns16550_lsr_read(&ns16550) & LSR_DATA_READY))
132	ns16550_rbr_read(&ns16550);	132	ns16550_rbr_read(&ns16550);
133		133
134	sysinfo_set_item_val("kbd", NULL, true);	134	sysinfo_set_item_val("kbd", NULL, true);
135	sysinfo_set_item_val("kbd.type", NULL, KBD_NS16550);	135	sysinfo_set_item_val("kbd.type", NULL, KBD_NS16550);
136	sysinfo_set_item_val("kbd.devno", NULL, devno);	136	sysinfo_set_item_val("kbd.devno", NULL, devno);
137	sysinfo_set_item_val("kbd.inr", NULL, inr);	137	sysinfo_set_item_val("kbd.inr", NULL, inr);
138	sysinfo_set_item_val("kbd.address.virtual", NULL, port);	138	sysinfo_set_item_val("kbd.address.virtual", NULL, port);
139	sysinfo_set_item_val("kbd.port", NULL, port);	139	sysinfo_set_item_val("kbd.port", NULL, port);
140		140
141	/* Enable interrupts */	141	/* Enable interrupts */
142	ns16550_ier_write(&ns16550, IER_ERBFI);	142	ns16550_ier_write(&ns16550, IER_ERBFI);
143	ns16550_mcr_write(&ns16550, MCR_OUT2);	143	ns16550_mcr_write(&ns16550, MCR_OUT2);
144		144
145	uint8_t c;	145	uint8_t c;
146	// This switches rbr & ier to mode when accept baudrate constant	146	// This switches rbr & ier to mode when accept baudrate constant
147	c = ns16550_lcr_read(&ns16550);	147	c = ns16550_lcr_read(&ns16550);
148	ns16550_lcr_write(&ns16550, 0x80 \| c);	148	ns16550_lcr_write(&ns16550, 0x80 \| c);
149	ns16550_rbr_write(&ns16550, 0x0c);	149	ns16550_rbr_write(&ns16550, 0x0c);
150	ns16550_ier_write(&ns16550, 0x00);	150	ns16550_ier_write(&ns16550, 0x00);
151	ns16550_lcr_write(&ns16550, c);	151	ns16550_lcr_write(&ns16550, c);
152		152
153	ns16550_grab();	153	ns16550_grab();
154	}	154	}
155		155
156	/** Process ns16550 interrupt. */	156	/** Process ns16550 interrupt. */
157	void ns16550_interrupt(void)	157	void ns16550_interrupt(void)
158	{	158	{
159	ns16550_poll();	159	ns16550_poll();
160	}	160	}
161		161
162	/* Called from getc(). */	162	/* Called from getc(). */
163	void ns16550_resume(chardev_t *d)	163	void ns16550_resume(chardev_t *d)
164	{	164	{
165	}	165	}
166		166
167	/* Called from getc(). */	167	/* Called from getc(). */
168	void ns16550_suspend(chardev_t *d)	168	void ns16550_suspend(chardev_t *d)
169	{	169	{
170	}	170	}
171		171
172		172
173	char ns16550_key_read(chardev_t *d)	173	char ns16550_key_read(chardev_t *d)
174	{	174	{
175	char ch;	175	char ch;
176		176
177	while(!(ch = active_read_buff_read())) {	177	while(!(ch = active_read_buff_read())) {
178	uint8_t x;	178	uint8_t x;
179	while (!(ns16550_lsr_read(&ns16550) & LSR_DATA_READY));	179	while (!(ns16550_lsr_read(&ns16550) & LSR_DATA_READY));
180		180
181	x = ns16550_rbr_read(&ns16550);	181	x = ns16550_rbr_read(&ns16550);
182		182
183	if (x != IGNORE_CODE) {	183	if (x != IGNORE_CODE) {
184	if (x & KEY_RELEASE)	184	if (x & KEY_RELEASE)
185	key_released(x ^ KEY_RELEASE);	185	key_released(x ^ KEY_RELEASE);
186	else	186	else
187	active_read_key_pressed(x);	187	active_read_key_pressed(x);
188	}	188	}
189	}	189	}
190	return ch;	190	return ch;
191	}	191	}
192		192
193	/** Poll for key press and release events.	193	/** Poll for key press and release events.
194	*	194	*
195	* This function can be used to implement keyboard polling.	195	* This function can be used to implement keyboard polling.
196	*/	196	*/
197	void ns16550_poll(void)	197	void ns16550_poll(void)
198	{	198	{
199	while (ns16550_lsr_read(&ns16550) & LSR_DATA_READY) {	199	while (ns16550_lsr_read(&ns16550) & LSR_DATA_READY) {
200	uint8_t x;	200	uint8_t x;
201		201
202	x = ns16550_rbr_read(&ns16550);	202	x = ns16550_rbr_read(&ns16550);
203		203
204	if (x != IGNORE_CODE) {	204	if (x != IGNORE_CODE) {
205	if (x & KEY_RELEASE)	205	if (x & KEY_RELEASE)
206	key_released(x ^ KEY_RELEASE);	206	key_released(x ^ KEY_RELEASE);
207	else	207	else
208	key_pressed(x);	208	key_pressed(x);
209	}	209	}
210	}	210	}
211	}	211	}
212		212
213	irq_ownership_t ns16550_claim(void)	213	irq_ownership_t ns16550_claim(void *instance)
214	{	214	{
215	return (ns16550_lsr_read(&ns16550) & LSR_DATA_READY);	215	return (ns16550_lsr_read(&ns16550) & LSR_DATA_READY);
216	}	216	}
217		217
218	void ns16550_irq_handler(irq_t irq, void arg, ...)	218	void ns16550_irq_handler(irq_t *irq)
219	{	219	{
220	if (irq->notif_cfg.notify && irq->notif_cfg.answerbox)	220	if (irq->notif_cfg.notify && irq->notif_cfg.answerbox)
221	ipc_irq_send_notif(irq);	221	ipc_irq_send_notif(irq);
222	else	222	else
223	ns16550_interrupt();	223	ns16550_interrupt();
224	}	224	}
225		225
226	/** @}	226	/** @}
227	*/	227	*/
228		228

Subversion Repositories HelenOS

(root)/branches/dynload/kernel/genarch/src/drivers/ns16550/ns16550.c @ 4690 – Rev 3900 → 3906