altera_jtag_uart.c
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/*
* (C) Copyright 2004, Psyent Corporation <www.psyent.com>
* Scott McNutt <smcnutt@psyent.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <serial.h>
#include <asm/io.h>
DECLARE_GLOBAL_DATA_PTR;
/* data register */
#define ALTERA_JTAG_RVALID BIT(15) /* Read valid */
/* control register */
#define ALTERA_JTAG_AC BIT(10) /* activity indicator */
#define ALTERA_JTAG_RRDY BIT(12) /* read available */
#define ALTERA_JTAG_WSPACE(d) ((d) >> 16) /* Write space avail */
/* Write fifo size. FIXME: this should be extracted with sopc2dts */
#define ALTERA_JTAG_WRITE_DEPTH 64
struct altera_jtaguart_regs {
u32 data; /* Data register */
u32 control; /* Control register */
};
struct altera_jtaguart_platdata {
struct altera_jtaguart_regs *regs;
};
static int altera_jtaguart_setbrg(struct udevice *dev, int baudrate)
{
return 0;
}
static int altera_jtaguart_putc(struct udevice *dev, const char ch)
{
struct altera_jtaguart_platdata *plat = dev->platdata;
struct altera_jtaguart_regs *const regs = plat->regs;
u32 st = readl(®s->control);
#ifdef CONFIG_ALTERA_JTAG_UART_BYPASS
if (!(st & ALTERA_JTAG_AC)) /* no connection yet */
return -ENETUNREACH;
#endif
if (ALTERA_JTAG_WSPACE(st) == 0)
return -EAGAIN;
writel(ch, ®s->data);
return 0;
}
static int altera_jtaguart_pending(struct udevice *dev, bool input)
{
struct altera_jtaguart_platdata *plat = dev->platdata;
struct altera_jtaguart_regs *const regs = plat->regs;
u32 st = readl(®s->control);
if (input)
return st & ALTERA_JTAG_RRDY ? 1 : 0;
else
return !(ALTERA_JTAG_WSPACE(st) == ALTERA_JTAG_WRITE_DEPTH);
}
static int altera_jtaguart_getc(struct udevice *dev)
{
struct altera_jtaguart_platdata *plat = dev->platdata;
struct altera_jtaguart_regs *const regs = plat->regs;
u32 val;
val = readl(®s->data);
if (!(val & ALTERA_JTAG_RVALID))
return -EAGAIN;
return val & 0xff;
}
static int altera_jtaguart_probe(struct udevice *dev)
{
#ifdef CONFIG_ALTERA_JTAG_UART_BYPASS
struct altera_jtaguart_platdata *plat = dev->platdata;
struct altera_jtaguart_regs *const regs = plat->regs;
writel(ALTERA_JTAG_AC, ®s->control); /* clear AC flag */
#endif
return 0;
}
static int altera_jtaguart_ofdata_to_platdata(struct udevice *dev)
{
struct altera_jtaguart_platdata *plat = dev_get_platdata(dev);
plat->regs = map_physmem(devfdt_get_addr(dev),
sizeof(struct altera_jtaguart_regs),
MAP_NOCACHE);
return 0;
}
static const struct dm_serial_ops altera_jtaguart_ops = {
.putc = altera_jtaguart_putc,
.pending = altera_jtaguart_pending,
.getc = altera_jtaguart_getc,
.setbrg = altera_jtaguart_setbrg,
};
static const struct udevice_id altera_jtaguart_ids[] = {
{ .compatible = "altr,juart-1.0" },
{}
};
U_BOOT_DRIVER(altera_jtaguart) = {
.name = "altera_jtaguart",
.id = UCLASS_SERIAL,
.of_match = altera_jtaguart_ids,
.ofdata_to_platdata = altera_jtaguart_ofdata_to_platdata,
.platdata_auto_alloc_size = sizeof(struct altera_jtaguart_platdata),
.probe = altera_jtaguart_probe,
.ops = &altera_jtaguart_ops,
.flags = DM_FLAG_PRE_RELOC,
};
#ifdef CONFIG_DEBUG_UART_ALTERA_JTAGUART
#include <debug_uart.h>
static inline void _debug_uart_init(void)
{
}
static inline void _debug_uart_putc(int ch)
{
struct altera_jtaguart_regs *regs = (void *)CONFIG_DEBUG_UART_BASE;
while (1) {
u32 st = readl(®s->control);
if (ALTERA_JTAG_WSPACE(st))
break;
}
writel(ch, ®s->data);
}
DEBUG_UART_FUNCS
#endif