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// SPDX-License-Identifier: GPL-2.0
/*
* RT288x/Au1xxx driver
*/
#include <linux/module.h>
#include <linux/io.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/serial.h>
#include <linux/serial_8250.h>
#include "8250.h"
#define RT288X_DL 0x28
/* Au1x00/RT288x UART hardware has a weird register layout */
static const u8 au_io_in_map[7] = {
[UART_RX] = 0,
[UART_IER] = 2,
[UART_IIR] = 3,
[UART_LCR] = 5,
[UART_MCR] = 6,
[UART_LSR] = 7,
[UART_MSR] = 8,
};
static const u8 au_io_out_map[5] = {
[UART_TX] = 1,
[UART_IER] = 2,
[UART_FCR] = 4,
[UART_LCR] = 5,
[UART_MCR] = 6,
};
static unsigned int au_serial_in(struct uart_port *p, int offset)
{
if (offset >= ARRAY_SIZE(au_io_in_map))
return UINT_MAX;
offset = au_io_in_map[offset];
return __raw_readl(p->membase + (offset << p->regshift));
}
static void au_serial_out(struct uart_port *p, int offset, int value)
{
if (offset >= ARRAY_SIZE(au_io_out_map))
return;
offset = au_io_out_map[offset];
__raw_writel(value, p->membase + (offset << p->regshift));
}
/* Au1x00 haven't got a standard divisor latch */
static u32 au_serial_dl_read(struct uart_8250_port *up)
{
return __raw_readl(up->port.membase + RT288X_DL);
}
static void au_serial_dl_write(struct uart_8250_port *up, u32 value)
{
__raw_writel(value, up->port.membase + RT288X_DL);
}
int au_platform_setup(struct plat_serial8250_port *p)
{
p->iotype = UPIO_AU;
p->serial_in = au_serial_in;
p->serial_out = au_serial_out;
p->dl_read = au_serial_dl_read;
p->dl_write = au_serial_dl_write;
p->mapsize = 0x1000;
p->bugs |= UART_BUG_NOMSR;
return 0;
}
EXPORT_SYMBOL_GPL(au_platform_setup);
int rt288x_setup(struct uart_port *p)
{
struct uart_8250_port *up = up_to_u8250p(p);
p->iotype = UPIO_AU;
p->serial_in = au_serial_in;
p->serial_out = au_serial_out;
up->dl_read = au_serial_dl_read;
up->dl_write = au_serial_dl_write;
p->mapsize = 0x100;
up->bugs |= UART_BUG_NOMSR;
return 0;
}
EXPORT_SYMBOL_GPL(rt288x_setup);
#ifdef CONFIG_SERIAL_8250_CONSOLE
static void au_putc(struct uart_port *port, unsigned char c)
{
unsigned int status;
au_serial_out(port, UART_TX, c);
for (;;) {
status = au_serial_in(port, UART_LSR);
if (uart_lsr_tx_empty(status))
break;
cpu_relax();
}
}
static void au_early_serial8250_write(struct console *console,
const char *s, unsigned int count)
{
struct earlycon_device *device = console->data;
struct uart_port *port = &device->port;
uart_console_write(port, s, count, au_putc);
}
static int __init early_au_setup(struct earlycon_device *dev, const char *opt)
{
rt288x_setup(&dev->port);
dev->con->write = au_early_serial8250_write;
return 0;
}
OF_EARLYCON_DECLARE(palmchip, "ralink,rt2880-uart", early_au_setup);
#endif
MODULE_DESCRIPTION("RT288x/Au1xxx UART driver");
MODULE_LICENSE("GPL");
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