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

/*
 * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <common.h>
#include <dm.h>
#include <serial.h>

DECLARE_GLOBAL_DATA_PTR;

struct arc_serial_regs {
	unsigned int id0;
	unsigned int id1;
	unsigned int id2;
	unsigned int id3;
	unsigned int data;
	unsigned int status;
	unsigned int baudl;
	unsigned int baudh;
};


struct arc_serial_platdata {
	struct arc_serial_regs *reg;
	unsigned int uartclk;
};

/* Bit definitions of STATUS register */
#define UART_RXEMPTY		(1 << 5)
#define UART_OVERFLOW_ERR	(1 << 1)
#define UART_TXEMPTY		(1 << 7)

static int arc_serial_setbrg(struct udevice *dev, int baudrate)
{
	struct arc_serial_platdata *plat = dev->platdata;
	struct arc_serial_regs *const regs = plat->reg;
	int arc_console_baud = gd->cpu_clk / (baudrate * 4) - 1;

	writeb(arc_console_baud & 0xff, &regs->baudl);

#ifdef CONFIG_ARC
	/*
	 * UART ISS(Instruction Set simulator) emulation has a subtle bug:
	 * A existing value of Baudh = 0 is used as a indication to startup
	 * it's internal state machine.
	 * Thus if baudh is set to 0, 2 times, it chokes.
	 * This happens with BAUD=115200 and the formaula above
	 * Until that is fixed, when running on ISS, we will set baudh to !0
	 */
	if (gd->arch.running_on_hw)
		writeb((arc_console_baud & 0xff00) >> 8, &regs->baudh);
	else
		writeb(1, &regs->baudh);
#else
	writeb((arc_console_baud & 0xff00) >> 8, &regs->baudh);
#endif

	return 0;
}

static int arc_serial_putc(struct udevice *dev, const char c)
{
	struct arc_serial_platdata *plat = dev->platdata;
	struct arc_serial_regs *const regs = plat->reg;

	if (c == '\n')
		arc_serial_putc(dev, '\r');

	while (!(readb(&regs->status) & UART_TXEMPTY))
		;

	writeb(c, &regs->data);

	return 0;
}

static int arc_serial_tstc(struct arc_serial_regs *const regs)
{
	return !(readb(&regs->status) & UART_RXEMPTY);
}

static int arc_serial_pending(struct udevice *dev, bool input)
{
	struct arc_serial_platdata *plat = dev->platdata;
	struct arc_serial_regs *const regs = plat->reg;
	uint32_t status = readb(&regs->status);

	if (input)
		return status & UART_RXEMPTY ? 0 : 1;
	else
		return status & UART_TXEMPTY ? 0 : 1;
}

static int arc_serial_getc(struct udevice *dev)
{
	struct arc_serial_platdata *plat = dev->platdata;
	struct arc_serial_regs *const regs = plat->reg;

	while (!arc_serial_tstc(regs))
		;

	/* Check for overflow errors */
	if (readb(&regs->status) & UART_OVERFLOW_ERR)
		return 0;

	return readb(&regs->data) & 0xFF;
}

static int arc_serial_probe(struct udevice *dev)
{
	return 0;
}

static const struct dm_serial_ops arc_serial_ops = {
	.putc = arc_serial_putc,
	.pending = arc_serial_pending,
	.getc = arc_serial_getc,
	.setbrg = arc_serial_setbrg,
};

static const struct udevice_id arc_serial_ids[] = {
	{ .compatible = "snps,arc-uart" },
	{ }
};

static int arc_serial_ofdata_to_platdata(struct udevice *dev)
{
	struct arc_serial_platdata *plat = dev_get_platdata(dev);
	DECLARE_GLOBAL_DATA_PTR;

	plat->reg = (struct arc_serial_regs *)fdtdec_get_addr(gd->fdt_blob,
							dev->of_offset, "reg");
	plat->uartclk = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
				       "clock-frequency", 0);

	return 0;
}

U_BOOT_DRIVER(serial_arc) = {
	.name	= "serial_arc",
	.id	= UCLASS_SERIAL,
	.of_match = arc_serial_ids,
	.ofdata_to_platdata = arc_serial_ofdata_to_platdata,
	.probe = arc_serial_probe,
	.ops	= &arc_serial_ops,
	.flags = DM_FLAG_PRE_RELOC,
};
Commit	Line	Data
22a240c3 AB	1	/*
	2	* Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*
	8	*/
	9
	10	#include <common.h>
01496c4f	11	#include <dm.h>
22a240c3 AB	12	#include <serial.h>
	13
	14	DECLARE_GLOBAL_DATA_PTR;
	15
	16	struct arc_serial_regs {
	17	unsigned int id0;
	18	unsigned int id1;
	19	unsigned int id2;
	20	unsigned int id3;
	21	unsigned int data;
	22	unsigned int status;
	23	unsigned int baudl;
	24	unsigned int baudh;
	25	};
	26
01496c4f AB	27
	28	struct arc_serial_platdata {
	29	struct arc_serial_regs *reg;
	30	unsigned int uartclk;
	31	};
	32
22a240c3 AB	33	/* Bit definitions of STATUS register */
	34	#define UART_RXEMPTY (1 << 5)
	35	#define UART_OVERFLOW_ERR (1 << 1)
	36	#define UART_TXEMPTY (1 << 7)
	37
01496c4f	38	static int arc_serial_setbrg(struct udevice *dev, int baudrate)
22a240c3	39	{
01496c4f AB	40	struct arc_serial_platdata *plat = dev->platdata;
	41	struct arc_serial_regs *const regs = plat->reg;
	42	int arc_console_baud = gd->cpu_clk / (baudrate * 4) - 1;
22a240c3	43
94b5400e	44	writeb(arc_console_baud & 0xff, &regs->baudl);
1d568c76 AB	45
	46	#ifdef CONFIG_ARC
	47	/*
	48	* UART ISS(Instruction Set simulator) emulation has a subtle bug:
	49	* A existing value of Baudh = 0 is used as a indication to startup
	50	* it's internal state machine.
	51	* Thus if baudh is set to 0, 2 times, it chokes.
	52	* This happens with BAUD=115200 and the formaula above
	53	* Until that is fixed, when running on ISS, we will set baudh to !0
	54	*/
	55	if (gd->arch.running_on_hw)
94b5400e	56	writeb((arc_console_baud & 0xff00) >> 8, &regs->baudh);
1d568c76	57	else
94b5400e	58	writeb(1, &regs->baudh);
1d568c76	59	#else
94b5400e	60	writeb((arc_console_baud & 0xff00) >> 8, &regs->baudh);
1d568c76	61	#endif
22a240c3	62
22a240c3 AB	63	return 0;
	64	}
	65
01496c4f	66	static int arc_serial_putc(struct udevice *dev, const char c)
22a240c3	67	{
01496c4f AB	68	struct arc_serial_platdata *plat = dev->platdata;
	69	struct arc_serial_regs *const regs = plat->reg;
	70
22a240c3	71	if (c == '\n')
01496c4f	72	arc_serial_putc(dev, '\r');
22a240c3	73
94b5400e	74	while (!(readb(&regs->status) & UART_TXEMPTY))
22a240c3 AB	75	;
22a240c3 AB	76
94b5400e	77	writeb(c, &regs->data);
01496c4f AB	78
01496c4f AB	79	return 0;
22a240c3 AB	80	}
22a240c3 AB	81
01496c4f	82	static int arc_serial_tstc(struct arc_serial_regs *const regs)
22a240c3	83	{
94b5400e	84	return !(readb(&regs->status) & UART_RXEMPTY);
22a240c3 AB	85	}
22a240c3 AB	86
01496c4f AB	87	static int arc_serial_pending(struct udevice *dev, bool input)
	88	{
	89	struct arc_serial_platdata *plat = dev->platdata;
	90	struct arc_serial_regs *const regs = plat->reg;
	91	uint32_t status = readb(&regs->status);
	92
	93	if (input)
	94	return status & UART_RXEMPTY ? 0 : 1;
	95	else
	96	return status & UART_TXEMPTY ? 0 : 1;
	97	}
	98
	99	static int arc_serial_getc(struct udevice *dev)
22a240c3	100	{
01496c4f AB	101	struct arc_serial_platdata *plat = dev->platdata;
	102	struct arc_serial_regs *const regs = plat->reg;
	103
	104	while (!arc_serial_tstc(regs))
22a240c3 AB	105	;
	106
	107	/* Check for overflow errors */
94b5400e	108	if (readb(&regs->status) & UART_OVERFLOW_ERR)
22a240c3 AB	109	return 0;
22a240c3 AB	110
94b5400e	111	return readb(&regs->data) & 0xFF;
22a240c3 AB	112	}
22a240c3 AB	113
01496c4f	114	static int arc_serial_probe(struct udevice *dev)
22a240c3	115	{
01496c4f	116	return 0;
22a240c3 AB	117	}
22a240c3 AB	118
01496c4f AB	119	static const struct dm_serial_ops arc_serial_ops = {
	120	.putc = arc_serial_putc,
	121	.pending = arc_serial_pending,
	122	.getc = arc_serial_getc,
	123	.setbrg = arc_serial_setbrg,
	124	};
	125
	126	static const struct udevice_id arc_serial_ids[] = {
	127	{ .compatible = "snps,arc-uart" },
	128	{ }
	129	};
	130
	131	static int arc_serial_ofdata_to_platdata(struct udevice *dev)
22a240c3	132	{
01496c4f AB	133	struct arc_serial_platdata *plat = dev_get_platdata(dev);
	134	DECLARE_GLOBAL_DATA_PTR;
	135
	136	plat->reg = (struct arc_serial_regs *)fdtdec_get_addr(gd->fdt_blob,
	137	dev->of_offset, "reg");
	138	plat->uartclk = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
	139	"clock-frequency", 0);
	140
	141	return 0;
22a240c3	142	}
01496c4f AB	143
	144	U_BOOT_DRIVER(serial_arc) = {
	145	.name = "serial_arc",
	146	.id = UCLASS_SERIAL,
	147	.of_match = arc_serial_ids,
	148	.ofdata_to_platdata = arc_serial_ofdata_to_platdata,
	149	.probe = arc_serial_probe,
	150	.ops = &arc_serial_ops,
	151	.flags = DM_FLAG_PRE_RELOC,
	152	};