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/*
* Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
*
* Derived from linux/drivers/tty/serial/bcm63xx_uart.c:
* Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <clk.h>
#include <dm.h>
#include <debug_uart.h>
#include <errno.h>
#include <serial.h>
#include <asm/io.h>
#include <asm/types.h>
/* UART Control register */
#define UART_CTL_REG 0x0
#define UART_CTL_RXTIMEOUT_MASK 0x1f
#define UART_CTL_RXTIMEOUT_5 0x5
#define UART_CTL_RSTRXFIFO_SHIFT 6
#define UART_CTL_RSTRXFIFO_MASK (1 << UART_CTL_RSTRXFIFO_SHIFT)
#define UART_CTL_RSTTXFIFO_SHIFT 7
#define UART_CTL_RSTTXFIFO_MASK (1 << UART_CTL_RSTTXFIFO_SHIFT)
#define UART_CTL_STOPBITS_SHIFT 8
#define UART_CTL_STOPBITS_MASK (0xf << UART_CTL_STOPBITS_SHIFT)
#define UART_CTL_STOPBITS_1 (0x7 << UART_CTL_STOPBITS_SHIFT)
#define UART_CTL_BITSPERSYM_SHIFT 12
#define UART_CTL_BITSPERSYM_MASK (0x3 << UART_CTL_BITSPERSYM_SHIFT)
#define UART_CTL_BITSPERSYM_8 (0x3 << UART_CTL_BITSPERSYM_SHIFT)
#define UART_CTL_XMITBRK_SHIFT 14
#define UART_CTL_XMITBRK_MASK (1 << UART_CTL_XMITBRK_SHIFT)
#define UART_CTL_RSVD_SHIFT 15
#define UART_CTL_RSVD_MASK (1 << UART_CTL_RSVD_SHIFT)
#define UART_CTL_RXPAREVEN_SHIFT 16
#define UART_CTL_RXPAREVEN_MASK (1 << UART_CTL_RXPAREVEN_SHIFT)
#define UART_CTL_RXPAREN_SHIFT 17
#define UART_CTL_RXPAREN_MASK (1 << UART_CTL_RXPAREN_SHIFT)
#define UART_CTL_TXPAREVEN_SHIFT 18
#define UART_CTL_TXPAREVEN_MASK (1 << UART_CTL_TXPAREVEN_SHIFT)
#define UART_CTL_TXPAREN_SHIFT 19
#define UART_CTL_TXPAREN_MASK (1 << UART_CTL_TXPAREN_SHIFT)
#define UART_CTL_LOOPBACK_SHIFT 20
#define UART_CTL_LOOPBACK_MASK (1 << UART_CTL_LOOPBACK_SHIFT)
#define UART_CTL_RXEN_SHIFT 21
#define UART_CTL_RXEN_MASK (1 << UART_CTL_RXEN_SHIFT)
#define UART_CTL_TXEN_SHIFT 22
#define UART_CTL_TXEN_MASK (1 << UART_CTL_TXEN_SHIFT)
#define UART_CTL_BRGEN_SHIFT 23
#define UART_CTL_BRGEN_MASK (1 << UART_CTL_BRGEN_SHIFT)
/* UART Baudword register */
#define UART_BAUD_REG 0x4
/* UART FIFO Config register */
#define UART_FIFO_CFG_REG 0x8
#define UART_FIFO_CFG_RX_SHIFT 8
#define UART_FIFO_CFG_RX_MASK (0xf << UART_FIFO_CFG_RX_SHIFT)
#define UART_FIFO_CFG_RX_4 (0x4 << UART_FIFO_CFG_RX_SHIFT)
#define UART_FIFO_CFG_TX_SHIFT 12
#define UART_FIFO_CFG_TX_MASK (0xf << UART_FIFO_CFG_TX_SHIFT)
#define UART_FIFO_CFG_TX_4 (0x4 << UART_FIFO_CFG_TX_SHIFT)
/* UART Interrupt register */
#define UART_IR_REG 0x10
#define UART_IR_STAT(x) (1 << (x))
#define UART_IR_TXEMPTY 5
#define UART_IR_RXOVER 7
#define UART_IR_RXNOTEMPTY 11
/* UART FIFO register */
#define UART_FIFO_REG 0x14
#define UART_FIFO_VALID_MASK 0xff
#define UART_FIFO_FRAMEERR_SHIFT 8
#define UART_FIFO_FRAMEERR_MASK (1 << UART_FIFO_FRAMEERR_SHIFT)
#define UART_FIFO_PARERR_SHIFT 9
#define UART_FIFO_PARERR_MASK (1 << UART_FIFO_PARERR_SHIFT)
#define UART_FIFO_BRKDET_SHIFT 10
#define UART_FIFO_BRKDET_MASK (1 << UART_FIFO_BRKDET_SHIFT)
#define UART_FIFO_ANYERR_MASK (UART_FIFO_FRAMEERR_MASK | \
UART_FIFO_PARERR_MASK | \
UART_FIFO_BRKDET_MASK)
struct bcm6345_serial_priv {
void __iomem *base;
ulong uartclk;
};
/* enable rx & tx operation on uart */
static void bcm6345_serial_enable(void __iomem *base)
{
setbits_be32(base + UART_CTL_REG, UART_CTL_BRGEN_MASK |
UART_CTL_TXEN_MASK | UART_CTL_RXEN_MASK);
}
/* disable rx & tx operation on uart */
static void bcm6345_serial_disable(void __iomem *base)
{
clrbits_be32(base + UART_CTL_REG, UART_CTL_BRGEN_MASK |
UART_CTL_TXEN_MASK | UART_CTL_RXEN_MASK);
}
/* clear all unread data in rx fifo and unsent data in tx fifo */
static void bcm6345_serial_flush(void __iomem *base)
{
/* empty rx and tx fifo */
setbits_be32(base + UART_CTL_REG, UART_CTL_RSTRXFIFO_MASK |
UART_CTL_RSTTXFIFO_MASK);
/* read any pending char to make sure all irq status are cleared */
readl_be(base + UART_FIFO_REG);
}
static int bcm6345_serial_init(void __iomem *base, ulong clk, u32 baudrate)
{
u32 val;
/* mask all irq and flush port */
bcm6345_serial_disable(base);
bcm6345_serial_flush(base);
/* set uart control config */
clrsetbits_be32(base + UART_CTL_REG,
/* clear rx timeout */
UART_CTL_RXTIMEOUT_MASK |
/* clear stop bits */
UART_CTL_STOPBITS_MASK |
/* clear bits per symbol */
UART_CTL_BITSPERSYM_MASK |
/* clear xmit break */
UART_CTL_XMITBRK_MASK |
/* clear reserved bit */
UART_CTL_RSVD_MASK |
/* disable parity */
UART_CTL_RXPAREN_MASK |
UART_CTL_TXPAREN_MASK |
/* disable loopback */
UART_CTL_LOOPBACK_MASK,
/* set timeout to 5 */
UART_CTL_RXTIMEOUT_5 |
/* set 8 bits/symbol */
UART_CTL_BITSPERSYM_8 |
/* set 1 stop bit */
UART_CTL_STOPBITS_1 |
/* set parity to even */
UART_CTL_RXPAREVEN_MASK |
UART_CTL_TXPAREVEN_MASK);
/* set uart fifo config */
clrsetbits_be32(base + UART_FIFO_CFG_REG,
/* clear fifo config */
UART_FIFO_CFG_RX_MASK |
UART_FIFO_CFG_TX_MASK,
/* set fifo config to 4 */
UART_FIFO_CFG_RX_4 |
UART_FIFO_CFG_TX_4);
/* set baud rate */
val = ((clk / baudrate) >> 4);
if (val & 0x1)
val = (val >> 1);
else
val = (val >> 1) - 1;
writel_be(val, base + UART_BAUD_REG);
/* clear interrupts */
writel_be(0, base + UART_IR_REG);
/* enable uart */
bcm6345_serial_enable(base);
return 0;
}
static int bcm6345_serial_pending(struct udevice *dev, bool input)
{
struct bcm6345_serial_priv *priv = dev_get_priv(dev);
u32 val = readl_be(priv->base + UART_IR_REG);
if (input)
return !!(val & UART_IR_STAT(UART_IR_RXNOTEMPTY));
else
return !(val & UART_IR_STAT(UART_IR_TXEMPTY));
}
static int bcm6345_serial_setbrg(struct udevice *dev, int baudrate)
{
struct bcm6345_serial_priv *priv = dev_get_priv(dev);
return bcm6345_serial_init(priv->base, priv->uartclk, baudrate);
}
static int bcm6345_serial_putc(struct udevice *dev, const char ch)
{
struct bcm6345_serial_priv *priv = dev_get_priv(dev);
u32 val;
val = readl_be(priv->base + UART_IR_REG);
if (!(val & UART_IR_STAT(UART_IR_TXEMPTY)))
return -EAGAIN;
writel_be(ch, priv->base + UART_FIFO_REG);
return 0;
}
static int bcm6345_serial_getc(struct udevice *dev)
{
struct bcm6345_serial_priv *priv = dev_get_priv(dev);
u32 val;
val = readl_be(priv->base + UART_IR_REG);
if (val & UART_IR_STAT(UART_IR_RXOVER))
setbits_be32(priv->base + UART_CTL_REG,
UART_CTL_RSTRXFIFO_MASK);
if (!(val & UART_IR_STAT(UART_IR_RXNOTEMPTY)))
return -EAGAIN;
val = readl_be(priv->base + UART_FIFO_REG);
if (val & UART_FIFO_ANYERR_MASK)
return -EAGAIN;
return val & UART_FIFO_VALID_MASK;
}
static int bcm6345_serial_probe(struct udevice *dev)
{
struct bcm6345_serial_priv *priv = dev_get_priv(dev);
struct clk clk;
fdt_addr_t addr;
fdt_size_t size;
int ret;
/* get address */
addr = devfdt_get_addr_size_index(dev, 0, &size);
if (addr == FDT_ADDR_T_NONE)
return -EINVAL;
priv->base = ioremap(addr, size);
/* get clock rate */
ret = clk_get_by_index(dev, 0, &clk);
if (ret < 0)
return ret;
priv->uartclk = clk_get_rate(&clk);
clk_free(&clk);
/* initialize serial */
return bcm6345_serial_init(priv->base, priv->uartclk, CONFIG_BAUDRATE);
}
static const struct dm_serial_ops bcm6345_serial_ops = {
.putc = bcm6345_serial_putc,
.pending = bcm6345_serial_pending,
.getc = bcm6345_serial_getc,
.setbrg = bcm6345_serial_setbrg,
};
static const struct udevice_id bcm6345_serial_ids[] = {
{ .compatible = "brcm,bcm6345-uart" },
{ /* sentinel */ }
};
U_BOOT_DRIVER(bcm6345_serial) = {
.name = "bcm6345-uart",
.id = UCLASS_SERIAL,
.of_match = bcm6345_serial_ids,
.probe = bcm6345_serial_probe,
.priv_auto_alloc_size = sizeof(struct bcm6345_serial_priv),
.ops = &bcm6345_serial_ops,
.flags = DM_FLAG_PRE_RELOC,
};
#ifdef CONFIG_DEBUG_UART_BCM6345
static inline void _debug_uart_init(void)
{
void __iomem *base = (void __iomem *)CONFIG_DEBUG_UART_BASE;
bcm6345_serial_init(base, CONFIG_DEBUG_UART_CLOCK, CONFIG_BAUDRATE);
}
static inline void wait_xfered(void __iomem *base)
{
do {
u32 val = readl_be(base + UART_IR_REG);
if (val & UART_IR_STAT(UART_IR_TXEMPTY))
break;
} while (1);
}
static inline void _debug_uart_putc(int ch)
{
void __iomem *base = (void __iomem *)CONFIG_DEBUG_UART_BASE;
wait_xfered(base);
writel_be(ch, base + UART_FIFO_REG);
wait_xfered(base);
}
DEBUG_UART_FUNCS
#endif
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