u-boot/drivers/serial/serial_xuartlite.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2008 - 2015 Michal Simek <monstr@monstr.eu>
* Clean driver and add xilinx constant from header file
*
* (C) Copyright 2004 Atmark Techno, Inc.
* Yasushi SHOJI <yashi@atmark-techno.com>
*/
#include <config.h>
#include <common.h>
#include <dm.h>
#include <asm/io.h>
#include <linux/bitops.h>
#include <linux/compiler.h>
#include <serial.h>
#define SR_TX_FIFO_FULL BIT(3) /* transmit FIFO full */
#define SR_TX_FIFO_EMPTY BIT(2) /* transmit FIFO empty */
#define SR_RX_FIFO_VALID_DATA BIT(0) /* data in receive FIFO */
#define SR_RX_FIFO_FULL BIT(1) /* receive FIFO full */
#define ULITE_CONTROL_RST_TX 0x01
#define ULITE_CONTROL_RST_RX 0x02
static bool little_endian;
struct uartlite {
unsigned int rx_fifo;
unsigned int tx_fifo;
unsigned int status;
unsigned int control;
};
struct uartlite_plat {
struct uartlite *regs;
};
static u32 uart_in32(void __iomem *addr)
{
if (little_endian)
return in_le32(addr);
else
return in_be32(addr);
}
static void uart_out32(void __iomem *addr, u32 val)
{
if (little_endian)
out_le32(addr, val);
else
out_be32(addr, val);
}
static int uartlite_serial_putc(struct udevice *dev, const char ch)
{
struct uartlite_plat *plat = dev_get_plat(dev);
struct uartlite *regs = plat->regs;
if (uart_in32(&regs->status) & SR_TX_FIFO_FULL)
return -EAGAIN;
uart_out32(&regs->tx_fifo, ch & 0xff);
return 0;
}
static int uartlite_serial_getc(struct udevice *dev)
{
struct uartlite_plat *plat = dev_get_plat(dev);
struct uartlite *regs = plat->regs;
if (!(uart_in32(&regs->status) & SR_RX_FIFO_VALID_DATA))
return -EAGAIN;
return uart_in32(&regs->rx_fifo) & 0xff;
}
static int uartlite_serial_pending(struct udevice *dev, bool input)
{
struct uartlite_plat *plat = dev_get_plat(dev);
struct uartlite *regs = plat->regs;
if (input)
return uart_in32(&regs->status) & SR_RX_FIFO_VALID_DATA;
return !(uart_in32(&regs->status) & SR_TX_FIFO_EMPTY);
}
static int uartlite_serial_probe(struct udevice *dev)
{
struct uartlite_plat *plat = dev_get_plat(dev);
struct uartlite *regs = plat->regs;
int ret;
uart_out32(&regs->control, 0);
uart_out32(&regs->control, ULITE_CONTROL_RST_RX | ULITE_CONTROL_RST_TX);
ret = uart_in32(&regs->status);
/* Endianness detection */
if ((ret & SR_TX_FIFO_EMPTY) != SR_TX_FIFO_EMPTY) {
little_endian = true;
uart_out32(&regs->control, ULITE_CONTROL_RST_RX |
ULITE_CONTROL_RST_TX);
}
return 0;
}
static int uartlite_serial_of_to_plat(struct udevice *dev)
{
struct uartlite_plat *plat = dev_get_plat(dev);
plat->regs = dev_read_addr_ptr(dev);
return 0;
}
static const struct dm_serial_ops uartlite_serial_ops = {
.putc = uartlite_serial_putc,
.pending = uartlite_serial_pending,
.getc = uartlite_serial_getc,
};
static const struct udevice_id uartlite_serial_ids[] = {
{ .compatible = "xlnx,opb-uartlite-1.00.b", },
{ .compatible = "xlnx,xps-uartlite-1.00.a" },
{ }
};
U_BOOT_DRIVER(serial_uartlite) = {
.name = "serial_uartlite",
.id = UCLASS_SERIAL,
.of_match = uartlite_serial_ids,
.of_to_plat = uartlite_serial_of_to_plat,
.plat_auto = sizeof(struct uartlite_plat),
.probe = uartlite_serial_probe,
.ops = &uartlite_serial_ops,
};
#ifdef CONFIG_DEBUG_UART_UARTLITE
#include <debug_uart.h>
static inline void _debug_uart_init(void)
{
struct uartlite *regs = (struct uartlite *)CONFIG_VAL(DEBUG_UART_BASE);
int ret;
uart_out32(&regs->control, 0);
uart_out32(&regs->control, ULITE_CONTROL_RST_RX | ULITE_CONTROL_RST_TX);
ret = uart_in32(&regs->status);
/* Endianness detection */
if ((ret & SR_TX_FIFO_EMPTY) != SR_TX_FIFO_EMPTY) {
little_endian = true;
uart_out32(&regs->control, ULITE_CONTROL_RST_RX |
ULITE_CONTROL_RST_TX);
}
}
static inline void _debug_uart_putc(int ch)
{
struct uartlite *regs = (struct uartlite *)CONFIG_VAL(DEBUG_UART_BASE);
while (uart_in32(&regs->status) & SR_TX_FIFO_FULL)
;
uart_out32(&regs->tx_fifo, ch & 0xff);
}
DEBUG_UART_FUNCS
#endif