blob: 071bd09fef69a9cb4a5735f979e4e031bb8713c1 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2023 Marek Vasut <marex@denx.de>
*/
#include <dm.h>
#include <malloc.h>
#include <serial.h>
#include <wait_bit.h>
#define SET_REG 0x4
#define CLR_REG 0x8
#define AUART_CTRL0 0x00
#define AUART_CTRL1 0x10
#define AUART_CTRL2 0x20
#define AUART_LINECTRL 0x30
#define AUART_INTR 0x50
#define AUART_DATA 0x60
#define AUART_STAT 0x70
#define AUART_CTRL0_SFTRST BIT(31)
#define AUART_CTRL0_CLKGATE BIT(30)
#define AUART_CTRL2_UARTEN BIT(0)
#define AUART_LINECTRL_BAUD_DIVINT(v) (((v) & 0xffff) << 16)
#define AUART_LINECTRL_BAUD_DIVFRAC(v) (((v) & 0x3f) << 8)
#define AUART_LINECTRL_WLEN(v) ((((v) - 5) & 0x3) << 5)
#define AUART_STAT_TXFE BIT(27)
#define AUART_STAT_TXFF BIT(25)
#define AUART_STAT_RXFE BIT(24)
#define AUART_CLK 24000000
struct mxs_auart_uart_priv {
void __iomem *base;
};
static int mxs_auart_uart_setbrg(struct udevice *dev, int baudrate)
{
struct mxs_auart_uart_priv *priv = dev_get_priv(dev);
u32 div;
writel(AUART_CTRL0_CLKGATE, priv->base + AUART_CTRL0 + CLR_REG);
writel(AUART_CTRL0_SFTRST, priv->base + AUART_CTRL0 + CLR_REG);
writel(AUART_CTRL2_UARTEN, priv->base + AUART_CTRL2 + SET_REG);
writel(0, priv->base + AUART_INTR);
div = DIV_ROUND_CLOSEST(AUART_CLK * 32, baudrate);
/* Disable FIFO, baudrate, 8N1. */
writel(AUART_LINECTRL_BAUD_DIVFRAC(div & 0x3F) |
AUART_LINECTRL_BAUD_DIVINT(div >> 6) |
AUART_LINECTRL_WLEN(8),
priv->base + AUART_LINECTRL);
return 0;
}
static int mxs_auart_uart_pending(struct udevice *dev, bool input)
{
struct mxs_auart_uart_priv *priv = dev_get_priv(dev);
u32 stat = readl(priv->base + AUART_STAT);
if (input)
return !(stat & AUART_STAT_RXFE);
return !!(stat & AUART_STAT_TXFE);
}
static int mxs_auart_uart_putc(struct udevice *dev, const char ch)
{
struct mxs_auart_uart_priv *priv = dev_get_priv(dev);
u32 stat = readl(priv->base + AUART_STAT);
if (stat & AUART_STAT_TXFF)
return -EAGAIN;
writel(ch, priv->base + AUART_DATA);
return 0;
}
static int mxs_auart_uart_getc(struct udevice *dev)
{
struct mxs_auart_uart_priv *priv = dev_get_priv(dev);
if (!mxs_auart_uart_pending(dev, true))
return -EAGAIN;
return readl(priv->base + AUART_DATA) & 0xff;
}
static int mxs_auart_uart_probe(struct udevice *dev)
{
struct mxs_auart_uart_priv *priv = dev_get_priv(dev);
priv->base = dev_read_addr_ptr(dev);
if (!priv->base)
return -EINVAL;
return mxs_auart_uart_setbrg(dev, CONFIG_BAUDRATE);
}
static const struct dm_serial_ops mxs_auart_uart_ops = {
.putc = mxs_auart_uart_putc,
.pending = mxs_auart_uart_pending,
.getc = mxs_auart_uart_getc,
.setbrg = mxs_auart_uart_setbrg,
};
static const struct udevice_id mxs_auart_uart_ids[] = {
{ .compatible = "fsl,imx23-auart", },
{ .compatible = "fsl,imx28-auart", },
{ /* sentinel */ }
};
U_BOOT_DRIVER(mxs_auart_serial) = {
.name = "mxs-auart",
.id = UCLASS_SERIAL,
.of_match = mxs_auart_uart_ids,
.probe = mxs_auart_uart_probe,
.ops = &mxs_auart_uart_ops,
.priv_auto = sizeof(struct mxs_auart_uart_priv),
};