[people/ms/u-boot.git] / drivers / serial / ns16550.c

/*
 * COM1 NS16550 support
 * originally from linux source (arch/powerpc/boot/ns16550.c)
 * modified to use CONFIG_SYS_ISA_MEM and new defines
 */

#include <common.h>
#include <dm.h>
#include <errno.h>
#include <fdtdec.h>
#include <ns16550.h>
#include <serial.h>
#include <watchdog.h>
#include <linux/types.h>
#include <asm/io.h>

DECLARE_GLOBAL_DATA_PTR;

#define UART_LCRVAL UART_LCR_8N1		/* 8 data, 1 stop, no parity */
#define UART_MCRVAL (UART_MCR_DTR | \
		     UART_MCR_RTS)		/* RTS/DTR */
#define UART_FCRVAL (UART_FCR_FIFO_EN |	\
		     UART_FCR_RXSR |	\
		     UART_FCR_TXSR)		/* Clear & enable FIFOs */

#ifndef CONFIG_DM_SERIAL
#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
#define serial_out(x, y)	outb(x, (ulong)y)
#define serial_in(y)		inb((ulong)y)
#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE > 0)
#define serial_out(x, y)	out_be32(y, x)
#define serial_in(y)		in_be32(y)
#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE < 0)
#define serial_out(x, y)	out_le32(y, x)
#define serial_in(y)		in_le32(y)
#else
#define serial_out(x, y)	writeb(x, y)
#define serial_in(y)		readb(y)
#endif
#endif /* !CONFIG_DM_SERIAL */

#if defined(CONFIG_SOC_KEYSTONE)
#define UART_REG_VAL_PWREMU_MGMT_UART_DISABLE   0
#define UART_REG_VAL_PWREMU_MGMT_UART_ENABLE ((1 << 14) | (1 << 13) | (1 << 0))
#undef UART_MCRVAL
#ifdef CONFIG_SERIAL_HW_FLOW_CONTROL
#define UART_MCRVAL             (UART_MCR_RTS | UART_MCR_AFE)
#else
#define UART_MCRVAL             (UART_MCR_RTS)
#endif
#endif

#ifndef CONFIG_SYS_NS16550_IER
#define CONFIG_SYS_NS16550_IER  0x00
#endif /* CONFIG_SYS_NS16550_IER */

#ifdef CONFIG_DM_SERIAL
static void ns16550_writeb(NS16550_t port, int offset, int value)
{
	struct ns16550_platdata *plat = port->plat;
	unsigned char *addr;

	offset *= 1 << plat->reg_shift;
	addr = map_sysmem(plat->base, 0) + offset;
	/*
	 * As far as we know it doesn't make sense to support selection of
	 * these options at run-time, so use the existing CONFIG options.
	 */
#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
	outb(value, addr);
#elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN)
	out_le32(addr, value);
#elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
	out_be32(addr, value);
#elif defined(CONFIG_SYS_BIG_ENDIAN)
	writeb(value, addr + (1 << plat->reg_shift) - 1);
#else
	writeb(value, addr);
#endif
}

static int ns16550_readb(NS16550_t port, int offset)
{
	struct ns16550_platdata *plat = port->plat;
	unsigned char *addr;

	offset *= 1 << plat->reg_shift;
	addr = map_sysmem(plat->base, 0) + offset;
#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
	return inb(addr);
#elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN)
	return in_le32(addr);
#elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
	return in_be32(addr);
#elif defined(CONFIG_SYS_BIG_ENDIAN)
	return readb(addr + (1 << plat->reg_shift) - 1);
#else
	return readb(addr);
#endif
}

/* We can clean these up once everything is moved to driver model */
#define serial_out(value, addr)	\
	ns16550_writeb(com_port, addr - (unsigned char *)com_port, value)
#define serial_in(addr) \
	ns16550_readb(com_port, addr - (unsigned char *)com_port)
#endif

int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate)
{
	const unsigned int mode_x_div = 16;

#ifdef CONFIG_OMAP1510
	/* If can't cleanly clock 115200 set div to 1 */
	if ((clock == 12000000) && (baudrate == 115200)) {
		port->osc_12m_sel = OSC_12M_SEL;  /* enable 6.5 * divisor */
		return 1;			/* return 1 for base divisor */
	}
	port->osc_12m_sel = 0;			/* clear if previsouly set */
#endif

	return DIV_ROUND_CLOSEST(clock, mode_x_div * baudrate);
}

static void NS16550_setbrg(NS16550_t com_port, int baud_divisor)
{
	serial_out(UART_LCR_BKSE | UART_LCRVAL, &com_port->lcr);
	serial_out(baud_divisor & 0xff, &com_port->dll);
	serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm);
	serial_out(UART_LCRVAL, &com_port->lcr);
}

void NS16550_init(NS16550_t com_port, int baud_divisor)
{
#if (defined(CONFIG_SPL_BUILD) && defined(CONFIG_OMAP34XX))
	/*
	 * On some OMAP3 devices when UART3 is configured for boot mode before
	 * SPL starts only THRE bit is set. We have to empty the transmitter
	 * before initialization starts.
	 */
	if ((serial_in(&com_port->lsr) & (UART_LSR_TEMT | UART_LSR_THRE))
	     == UART_LSR_THRE) {
		if (baud_divisor != -1)
			NS16550_setbrg(com_port, baud_divisor);
		serial_out(0, &com_port->mdr1);
	}
#endif

	while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT))
		;

	serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
#if defined(CONFIG_OMAP) || defined(CONFIG_AM33XX) || \
			defined(CONFIG_TI81XX) || defined(CONFIG_AM43XX)
	serial_out(0x7, &com_port->mdr1);	/* mode select reset TL16C750*/
#endif
	NS16550_setbrg(com_port, 0);
	serial_out(UART_MCRVAL, &com_port->mcr);
	serial_out(UART_FCRVAL, &com_port->fcr);
	if (baud_divisor != -1)
		NS16550_setbrg(com_port, baud_divisor);
#if defined(CONFIG_OMAP) || \
	defined(CONFIG_AM33XX) || defined(CONFIG_SOC_DA8XX) || \
	defined(CONFIG_TI81XX) || defined(CONFIG_AM43XX)

	/* /16 is proper to hit 115200 with 48MHz */
	serial_out(0, &com_port->mdr1);
#endif /* CONFIG_OMAP */
#if defined(CONFIG_SOC_KEYSTONE)
	serial_out(UART_REG_VAL_PWREMU_MGMT_UART_ENABLE, &com_port->regC);
#endif
}

#ifndef CONFIG_NS16550_MIN_FUNCTIONS
void NS16550_reinit(NS16550_t com_port, int baud_divisor)
{
	serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
	NS16550_setbrg(com_port, 0);
	serial_out(UART_MCRVAL, &com_port->mcr);
	serial_out(UART_FCRVAL, &com_port->fcr);
	NS16550_setbrg(com_port, baud_divisor);
}
#endif /* CONFIG_NS16550_MIN_FUNCTIONS */

void NS16550_putc(NS16550_t com_port, char c)
{
	while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0)
		;
	serial_out(c, &com_port->thr);

	/*
	 * Call watchdog_reset() upon newline. This is done here in putc
	 * since the environment code uses a single puts() to print the complete
	 * environment upon "printenv". So we can't put this watchdog call
	 * in puts().
	 */
	if (c == '\n')
		WATCHDOG_RESET();
}

#ifndef CONFIG_NS16550_MIN_FUNCTIONS
char NS16550_getc(NS16550_t com_port)
{
	while ((serial_in(&com_port->lsr) & UART_LSR_DR) == 0) {
#if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_USB_TTY)
		extern void usbtty_poll(void);
		usbtty_poll();
#endif
		WATCHDOG_RESET();
	}
	return serial_in(&com_port->rbr);
}

int NS16550_tstc(NS16550_t com_port)
{
	return (serial_in(&com_port->lsr) & UART_LSR_DR) != 0;
}

#endif /* CONFIG_NS16550_MIN_FUNCTIONS */

#ifdef CONFIG_DM_SERIAL
static int ns16550_serial_putc(struct udevice *dev, const char ch)
{
	struct NS16550 *const com_port = dev_get_priv(dev);

	if (!(serial_in(&com_port->lsr) & UART_LSR_THRE))
		return -EAGAIN;
	serial_out(ch, &com_port->thr);

	/*
	 * Call watchdog_reset() upon newline. This is done here in putc
	 * since the environment code uses a single puts() to print the complete
	 * environment upon "printenv". So we can't put this watchdog call
	 * in puts().
	 */
	if (ch == '\n')
		WATCHDOG_RESET();

	return 0;
}

static int ns16550_serial_pending(struct udevice *dev, bool input)
{
	struct NS16550 *const com_port = dev_get_priv(dev);

	if (input)
		return serial_in(&com_port->lsr) & UART_LSR_DR ? 1 : 0;
	else
		return serial_in(&com_port->lsr) & UART_LSR_THRE ? 0 : 1;
}

static int ns16550_serial_getc(struct udevice *dev)
{
	struct NS16550 *const com_port = dev_get_priv(dev);

	if (!(serial_in(&com_port->lsr) & UART_LSR_DR))
		return -EAGAIN;

	return serial_in(&com_port->rbr);
}

static int ns16550_serial_setbrg(struct udevice *dev, int baudrate)
{
	struct NS16550 *const com_port = dev_get_priv(dev);
	struct ns16550_platdata *plat = com_port->plat;
	int clock_divisor;

	clock_divisor = ns16550_calc_divisor(com_port, plat->clock, baudrate);

	NS16550_setbrg(com_port, clock_divisor);

	return 0;
}

int ns16550_serial_probe(struct udevice *dev)
{
	struct NS16550 *const com_port = dev_get_priv(dev);

	NS16550_init(com_port, -1);

	return 0;
}

int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
{
	struct NS16550 *const com_port = dev_get_priv(dev);
	struct ns16550_platdata *plat = dev->platdata;
	fdt_addr_t addr;

	addr = fdtdec_get_addr(gd->fdt_blob, dev->of_offset, "reg");
	if (addr == FDT_ADDR_T_NONE)
		return -EINVAL;

	plat->base = addr;
	plat->reg_shift = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
					 "reg-shift", 1);
	com_port->plat = plat;

	return 0;
}

const struct dm_serial_ops ns16550_serial_ops = {
	.putc = ns16550_serial_putc,
	.pending = ns16550_serial_pending,
	.getc = ns16550_serial_getc,
	.setbrg = ns16550_serial_setbrg,
};
#endif /* CONFIG_DM_SERIAL */
Commit	Line	Data
e85390dc WD	1	/*
e85390dc WD	2	* COM1 NS16550 support
a47a12be	3	* originally from linux source (arch/powerpc/boot/ns16550.c)
6d0f6bcf	4	* modified to use CONFIG_SYS_ISA_MEM and new defines
e85390dc WD	5	*/
e85390dc WD	6
fa54eb12	7	#include <common.h>
12e431b2 SG	8	#include <dm.h>
	9	#include <errno.h>
	10	#include <fdtdec.h>
e85390dc	11	#include <ns16550.h>
12e431b2	12	#include <serial.h>
a1b322a9	13	#include <watchdog.h>
167cdad1 GR	14	#include <linux/types.h>
167cdad1 GR	15	#include <asm/io.h>
e85390dc	16
12e431b2 SG	17	DECLARE_GLOBAL_DATA_PTR;
12e431b2 SG	18
200779e3 DZ	19	#define UART_LCRVAL UART_LCR_8N1 /* 8 data, 1 stop, no parity */
	20	#define UART_MCRVAL (UART_MCR_DTR \| \
	21	UART_MCR_RTS) /* RTS/DTR */
	22	#define UART_FCRVAL (UART_FCR_FIFO_EN \| \
	23	UART_FCR_RXSR \| \
	24	UART_FCR_TXSR) /* Clear & enable FIFOs */
12e431b2 SG	25
12e431b2 SG	26	#ifndef CONFIG_DM_SERIAL
167cdad1	27	#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
f8df9d0d SG	28	#define serial_out(x, y) outb(x, (ulong)y)
f8df9d0d SG	29	#define serial_in(y) inb((ulong)y)
79df1208	30	#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE > 0)
f8df9d0d SG	31	#define serial_out(x, y) out_be32(y, x)
f8df9d0d SG	32	#define serial_in(y) in_be32(y)
79df1208	33	#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE < 0)
f8df9d0d SG	34	#define serial_out(x, y) out_le32(y, x)
f8df9d0d SG	35	#define serial_in(y) in_le32(y)
167cdad1	36	#else
f8df9d0d SG	37	#define serial_out(x, y) writeb(x, y)
f8df9d0d SG	38	#define serial_in(y) readb(y)
167cdad1	39	#endif
12e431b2	40	#endif /* !CONFIG_DM_SERIAL */
e85390dc	41
7c387646	42	#if defined(CONFIG_SOC_KEYSTONE)
ef509b90 VA	43	#define UART_REG_VAL_PWREMU_MGMT_UART_DISABLE 0
ef509b90 VA	44	#define UART_REG_VAL_PWREMU_MGMT_UART_ENABLE ((1 << 14) \| (1 << 13) \| (1 << 0))
d57dee57 KM	45	#undef UART_MCRVAL
	46	#ifdef CONFIG_SERIAL_HW_FLOW_CONTROL
	47	#define UART_MCRVAL (UART_MCR_RTS \| UART_MCR_AFE)
	48	#else
	49	#define UART_MCRVAL (UART_MCR_RTS)
	50	#endif
ef509b90 VA	51	#endif
ef509b90 VA	52
a160ea0b PW	53	#ifndef CONFIG_SYS_NS16550_IER
	54	#define CONFIG_SYS_NS16550_IER 0x00
	55	#endif /* CONFIG_SYS_NS16550_IER */
	56
12e431b2 SG	57	#ifdef CONFIG_DM_SERIAL
	58	static void ns16550_writeb(NS16550_t port, int offset, int value)
	59	{
	60	struct ns16550_platdata *plat = port->plat;
	61	unsigned char *addr;
	62
	63	offset *= 1 << plat->reg_shift;
167efe01	64	addr = map_sysmem(plat->base, 0) + offset;
12e431b2 SG	65	/*
	66	* As far as we know it doesn't make sense to support selection of
	67	* these options at run-time, so use the existing CONFIG options.
	68	*/
	69	#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
	70	outb(value, addr);
	71	#elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN)
	72	out_le32(addr, value);
	73	#elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
	74	out_be32(addr, value);
	75	#elif defined(CONFIG_SYS_BIG_ENDIAN)
	76	writeb(value, addr + (1 << plat->reg_shift) - 1);
	77	#else
	78	writeb(value, addr);
	79	#endif
	80	}
	81
	82	static int ns16550_readb(NS16550_t port, int offset)
	83	{
	84	struct ns16550_platdata *plat = port->plat;
	85	unsigned char *addr;
	86
	87	offset *= 1 << plat->reg_shift;
167efe01	88	addr = map_sysmem(plat->base, 0) + offset;
12e431b2 SG	89	#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
	90	return inb(addr);
	91	#elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN)
	92	return in_le32(addr);
	93	#elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
	94	return in_be32(addr);
	95	#elif defined(CONFIG_SYS_BIG_ENDIAN)
	96	return readb(addr + (1 << plat->reg_shift) - 1);
	97	#else
	98	return readb(addr);
	99	#endif
	100	}
	101
	102	/* We can clean these up once everything is moved to driver model */
	103	#define serial_out(value, addr) \
	104	ns16550_writeb(com_port, addr - (unsigned char *)com_port, value)
	105	#define serial_in(addr) \
	106	ns16550_readb(com_port, addr - (unsigned char *)com_port)
	107	#endif
	108
fa54eb12 SG	109	int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate)
	110	{
	111	const unsigned int mode_x_div = 16;
	112
	113	#ifdef CONFIG_OMAP1510
	114	/* If can't cleanly clock 115200 set div to 1 */
	115	if ((clock == 12000000) && (baudrate == 115200)) {
	116	port->osc_12m_sel = OSC_12M_SEL; /* enable 6.5 * divisor */
	117	return 1; /* return 1 for base divisor */
	118	}
	119	port->osc_12m_sel = 0; /* clear if previsouly set */
	120	#endif
	121
	122	return DIV_ROUND_CLOSEST(clock, mode_x_div * baudrate);
	123	}
	124
8bbe33c8 SG	125	static void NS16550_setbrg(NS16550_t com_port, int baud_divisor)
	126	{
	127	serial_out(UART_LCR_BKSE \| UART_LCRVAL, &com_port->lcr);
	128	serial_out(baud_divisor & 0xff, &com_port->dll);
	129	serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm);
	130	serial_out(UART_LCRVAL, &com_port->lcr);
	131	}
	132
f8df9d0d	133	void NS16550_init(NS16550_t com_port, int baud_divisor)
e85390dc	134	{
fd2aeac5 MH	135	#if (defined(CONFIG_SPL_BUILD) && defined(CONFIG_OMAP34XX))
	136	/*
	137	* On some OMAP3 devices when UART3 is configured for boot mode before
	138	* SPL starts only THRE bit is set. We have to empty the transmitter
	139	* before initialization starts.
	140	*/
	141	if ((serial_in(&com_port->lsr) & (UART_LSR_TEMT \| UART_LSR_THRE))
	142	== UART_LSR_THRE) {
12e431b2 SG	143	if (baud_divisor != -1)
12e431b2 SG	144	NS16550_setbrg(com_port, baud_divisor);
fd2aeac5 MH	145	serial_out(0, &com_port->mdr1);
	146	}
	147	#endif
	148
cb55b332 SW	149	while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT))
	150	;
	151
a160ea0b	152	serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
456ccfdf TR	153	#if defined(CONFIG_OMAP) \|\| defined(CONFIG_AM33XX) \|\| \
456ccfdf TR	154	defined(CONFIG_TI81XX) \|\| defined(CONFIG_AM43XX)
167cdad1	155	serial_out(0x7, &com_port->mdr1); /* mode select reset TL16C750*/
945af8d7	156	#endif
8bbe33c8	157	NS16550_setbrg(com_port, 0);
167cdad1 GR	158	serial_out(UART_MCRVAL, &com_port->mcr);
167cdad1 GR	159	serial_out(UART_FCRVAL, &com_port->fcr);
12e431b2 SG	160	if (baud_divisor != -1)
12e431b2 SG	161	NS16550_setbrg(com_port, baud_divisor);
8ac22a60	162	#if defined(CONFIG_OMAP) \|\| \
6213a68f	163	defined(CONFIG_AM33XX) \|\| defined(CONFIG_SOC_DA8XX) \|\| \
9ed6e412	164	defined(CONFIG_TI81XX) \|\| defined(CONFIG_AM43XX)
5289e83a	165
f8df9d0d SG	166	/* /16 is proper to hit 115200 with 48MHz */
f8df9d0d SG	167	serial_out(0, &com_port->mdr1);
b4746d8b	168	#endif /* CONFIG_OMAP */
7c387646	169	#if defined(CONFIG_SOC_KEYSTONE)
ef509b90 VA	170	serial_out(UART_REG_VAL_PWREMU_MGMT_UART_ENABLE, &com_port->regC);
ef509b90 VA	171	#endif
e85390dc WD	172	}
e85390dc WD	173
f5675aa5	174	#ifndef CONFIG_NS16550_MIN_FUNCTIONS
f8df9d0d	175	void NS16550_reinit(NS16550_t com_port, int baud_divisor)
e85390dc	176	{
a160ea0b	177	serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
8bbe33c8	178	NS16550_setbrg(com_port, 0);
167cdad1 GR	179	serial_out(UART_MCRVAL, &com_port->mcr);
167cdad1 GR	180	serial_out(UART_FCRVAL, &com_port->fcr);
8bbe33c8	181	NS16550_setbrg(com_port, baud_divisor);
e85390dc	182	}
f5675aa5	183	#endif /* CONFIG_NS16550_MIN_FUNCTIONS */
e85390dc	184
f8df9d0d	185	void NS16550_putc(NS16550_t com_port, char c)
e85390dc	186	{
f8df9d0d SG	187	while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0)
f8df9d0d SG	188	;
167cdad1	189	serial_out(c, &com_port->thr);
1a2d9b30 SR	190
	191	/*
	192	* Call watchdog_reset() upon newline. This is done here in putc
	193	* since the environment code uses a single puts() to print the complete
	194	* environment upon "printenv". So we can't put this watchdog call
	195	* in puts().
	196	*/
	197	if (c == '\n')
	198	WATCHDOG_RESET();
e85390dc WD	199	}
e85390dc WD	200
f5675aa5	201	#ifndef CONFIG_NS16550_MIN_FUNCTIONS
f8df9d0d	202	char NS16550_getc(NS16550_t com_port)
e85390dc	203	{
167cdad1	204	while ((serial_in(&com_port->lsr) & UART_LSR_DR) == 0) {
f2041388	205	#if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_USB_TTY)
232c150a WD	206	extern void usbtty_poll(void);
	207	usbtty_poll();
	208	#endif
a1b322a9	209	WATCHDOG_RESET();
232c150a	210	}
167cdad1	211	return serial_in(&com_port->rbr);
e85390dc WD	212	}
e85390dc WD	213
f8df9d0d	214	int NS16550_tstc(NS16550_t com_port)
e85390dc	215	{
f8df9d0d	216	return (serial_in(&com_port->lsr) & UART_LSR_DR) != 0;
e85390dc WD	217	}
e85390dc WD	218
f5675aa5	219	#endif /* CONFIG_NS16550_MIN_FUNCTIONS */
12e431b2 SG	220
	221	#ifdef CONFIG_DM_SERIAL
	222	static int ns16550_serial_putc(struct udevice *dev, const char ch)
	223	{
	224	struct NS16550 *const com_port = dev_get_priv(dev);
	225
	226	if (!(serial_in(&com_port->lsr) & UART_LSR_THRE))
	227	return -EAGAIN;
	228	serial_out(ch, &com_port->thr);
	229
	230	/*
	231	* Call watchdog_reset() upon newline. This is done here in putc
	232	* since the environment code uses a single puts() to print the complete
	233	* environment upon "printenv". So we can't put this watchdog call
	234	* in puts().
	235	*/
	236	if (ch == '\n')
	237	WATCHDOG_RESET();
	238
	239	return 0;
	240	}
	241
	242	static int ns16550_serial_pending(struct udevice *dev, bool input)
	243	{
	244	struct NS16550 *const com_port = dev_get_priv(dev);
	245
	246	if (input)
	247	return serial_in(&com_port->lsr) & UART_LSR_DR ? 1 : 0;
	248	else
	249	return serial_in(&com_port->lsr) & UART_LSR_THRE ? 0 : 1;
	250	}
	251
	252	static int ns16550_serial_getc(struct udevice *dev)
	253	{
	254	struct NS16550 *const com_port = dev_get_priv(dev);
	255
aea2be20	256	if (!(serial_in(&com_port->lsr) & UART_LSR_DR))
12e431b2 SG	257	return -EAGAIN;
	258
	259	return serial_in(&com_port->rbr);
	260	}
	261
	262	static int ns16550_serial_setbrg(struct udevice *dev, int baudrate)
	263	{
	264	struct NS16550 *const com_port = dev_get_priv(dev);
	265	struct ns16550_platdata *plat = com_port->plat;
	266	int clock_divisor;
	267
	268	clock_divisor = ns16550_calc_divisor(com_port, plat->clock, baudrate);
	269
	270	NS16550_setbrg(com_port, clock_divisor);
	271
	272	return 0;
	273	}
	274
	275	int ns16550_serial_probe(struct udevice *dev)
	276	{
	277	struct NS16550 *const com_port = dev_get_priv(dev);
	278
	279	NS16550_init(com_port, -1);
	280
	281	return 0;
	282	}
	283
	284	int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
	285	{
	286	struct NS16550 *const com_port = dev_get_priv(dev);
	287	struct ns16550_platdata *plat = dev->platdata;
	288	fdt_addr_t addr;
	289
	290	addr = fdtdec_get_addr(gd->fdt_blob, dev->of_offset, "reg");
	291	if (addr == FDT_ADDR_T_NONE)
	292	return -EINVAL;
	293
167efe01	294	plat->base = addr;
12e431b2 SG	295	plat->reg_shift = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
	296	"reg-shift", 1);
	297	com_port->plat = plat;
	298
	299	return 0;
	300	}
	301
	302	const struct dm_serial_ops ns16550_serial_ops = {
	303	.putc = ns16550_serial_putc,
	304	.pending = ns16550_serial_pending,
	305	.getc = ns16550_serial_getc,
	306	.setbrg = ns16550_serial_setbrg,
	307	};
	308	#endif /* CONFIG_DM_SERIAL */