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/*
* Copyright (C) 2004-2006 Atmel Corporation
*
* Modified to support C structur SoC access by
* Andreas Bießmann <biessmann@corscience.de>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <watchdog.h>
#include <serial.h>
#include <linux/compiler.h>
#include <asm/io.h>
#ifdef CONFIG_DM_SERIAL
#include <asm/arch/atmel_serial.h>
#endif
#include <asm/arch/clk.h>
#include <asm/arch/hardware.h>
#include "atmel_usart.h"
DECLARE_GLOBAL_DATA_PTR;
static void atmel_serial_setbrg_internal(atmel_usart3_t *usart, int id,
int baudrate)
{
unsigned long divisor;
unsigned long usart_hz;
/*
* Master Clock
* Baud Rate = --------------
* 16 * CD
*/
usart_hz = get_usart_clk_rate(id);
divisor = (usart_hz / 16 + baudrate / 2) / baudrate;
writel(USART3_BF(CD, divisor), &usart->brgr);
}
static void atmel_serial_init_internal(atmel_usart3_t *usart)
{
/*
* Just in case: drain transmitter register
* 1000us is enough for baudrate >= 9600
*/
if (!(readl(&usart->csr) & USART3_BIT(TXEMPTY)))
__udelay(1000);
writel(USART3_BIT(RSTRX) | USART3_BIT(RSTTX), &usart->cr);
}
static void atmel_serial_activate(atmel_usart3_t *usart)
{
writel((USART3_BF(USART_MODE, USART3_USART_MODE_NORMAL)
| USART3_BF(USCLKS, USART3_USCLKS_MCK)
| USART3_BF(CHRL, USART3_CHRL_8)
| USART3_BF(PAR, USART3_PAR_NONE)
| USART3_BF(NBSTOP, USART3_NBSTOP_1)),
&usart->mr);
writel(USART3_BIT(RXEN) | USART3_BIT(TXEN), &usart->cr);
/* 100us is enough for the new settings to be settled */
__udelay(100);
}
#ifndef CONFIG_DM_SERIAL
static void atmel_serial_setbrg(void)
{
atmel_serial_setbrg_internal((atmel_usart3_t *)CONFIG_USART_BASE,
CONFIG_USART_ID, gd->baudrate);
}
static int atmel_serial_init(void)
{
atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE;
atmel_serial_init_internal(usart);
serial_setbrg();
atmel_serial_activate(usart);
return 0;
}
static void atmel_serial_putc(char c)
{
atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE;
if (c == '\n')
serial_putc('\r');
while (!(readl(&usart->csr) & USART3_BIT(TXRDY)));
writel(c, &usart->thr);
}
static int atmel_serial_getc(void)
{
atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE;
while (!(readl(&usart->csr) & USART3_BIT(RXRDY)))
WATCHDOG_RESET();
return readl(&usart->rhr);
}
static int atmel_serial_tstc(void)
{
atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE;
return (readl(&usart->csr) & USART3_BIT(RXRDY)) != 0;
}
static struct serial_device atmel_serial_drv = {
.name = "atmel_serial",
.start = atmel_serial_init,
.stop = NULL,
.setbrg = atmel_serial_setbrg,
.putc = atmel_serial_putc,
.puts = default_serial_puts,
.getc = atmel_serial_getc,
.tstc = atmel_serial_tstc,
};
void atmel_serial_initialize(void)
{
serial_register(&atmel_serial_drv);
}
__weak struct serial_device *default_serial_console(void)
{
return &atmel_serial_drv;
}
#endif
#ifdef CONFIG_DM_SERIAL
struct atmel_serial_priv {
atmel_usart3_t *usart;
};
int atmel_serial_setbrg(struct udevice *dev, int baudrate)
{
struct atmel_serial_priv *priv = dev_get_priv(dev);
atmel_serial_setbrg_internal(priv->usart, 0 /* ignored */, baudrate);
atmel_serial_activate(priv->usart);
return 0;
}
static int atmel_serial_getc(struct udevice *dev)
{
struct atmel_serial_priv *priv = dev_get_priv(dev);
if (!(readl(&priv->usart->csr) & USART3_BIT(RXRDY)))
return -EAGAIN;
return readl(&priv->usart->rhr);
}
static int atmel_serial_putc(struct udevice *dev, const char ch)
{
struct atmel_serial_priv *priv = dev_get_priv(dev);
if (!(readl(&priv->usart->csr) & USART3_BIT(TXRDY)))
return -EAGAIN;
writel(ch, &priv->usart->thr);
return 0;
}
static int atmel_serial_pending(struct udevice *dev, bool input)
{
struct atmel_serial_priv *priv = dev_get_priv(dev);
uint32_t csr = readl(&priv->usart->csr);
if (input)
return csr & USART3_BIT(RXRDY) ? 1 : 0;
else
return csr & USART3_BIT(TXEMPTY) ? 0 : 1;
}
static const struct dm_serial_ops atmel_serial_ops = {
.putc = atmel_serial_putc,
.pending = atmel_serial_pending,
.getc = atmel_serial_getc,
.setbrg = atmel_serial_setbrg,
};
static int atmel_serial_probe(struct udevice *dev)
{
struct atmel_serial_platdata *plat = dev->platdata;
struct atmel_serial_priv *priv = dev_get_priv(dev);
priv->usart = (atmel_usart3_t *)plat->base_addr;
atmel_serial_init_internal(priv->usart);
return 0;
}
U_BOOT_DRIVER(serial_atmel) = {
.name = "serial_atmel",
.id = UCLASS_SERIAL,
.probe = atmel_serial_probe,
.ops = &atmel_serial_ops,
.flags = DM_FLAG_PRE_RELOC,
.priv_auto_alloc_size = sizeof(struct atmel_serial_priv),
};
#endif
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