u-boot/drivers/serial/atmel_usart.c
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

321 lines
7 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2004-2006 Atmel Corporation
*
* Modified to support C structur SoC access by
* Andreas Bießmann <biessmann@corscience.de>
*/
#include <common.h>
#include <clk.h>
#include <dm.h>
#include <errno.h>
#include <watchdog.h>
#include <serial.h>
#include <debug_uart.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;
#ifndef CONFIG_DM_SERIAL
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);
}
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
enum serial_clk_type {
CLK_TYPE_NORMAL = 0,
CLK_TYPE_DBGU,
};
struct atmel_serial_priv {
atmel_usart3_t *usart;
ulong usart_clk_rate;
};
static void _atmel_serial_set_brg(atmel_usart3_t *usart,
ulong usart_clk_rate, int baudrate)
{
unsigned long divisor;
divisor = (usart_clk_rate / 16 + baudrate / 2) / baudrate;
writel(USART3_BF(CD, divisor), &usart->brgr);
}
void _atmel_serial_init(atmel_usart3_t *usart,
ulong usart_clk_rate, int baudrate)
{
writel(USART3_BIT(RXDIS) | USART3_BIT(TXDIS), &usart->cr);
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);
_atmel_serial_set_brg(usart, usart_clk_rate, baudrate);
writel(USART3_BIT(RSTRX) | USART3_BIT(RSTTX), &usart->cr);
writel(USART3_BIT(RXEN) | USART3_BIT(TXEN), &usart->cr);
}
int atmel_serial_setbrg(struct udevice *dev, int baudrate)
{
struct atmel_serial_priv *priv = dev_get_priv(dev);
_atmel_serial_set_brg(priv->usart, priv->usart_clk_rate, baudrate);
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_enable_clk(struct udevice *dev)
{
struct atmel_serial_priv *priv = dev_get_priv(dev);
struct clk clk;
ulong clk_rate;
int ret;
ret = clk_get_by_index(dev, 0, &clk);
if (ret)
return -EINVAL;
if (dev_get_driver_data(dev) == CLK_TYPE_NORMAL) {
ret = clk_enable(&clk);
if (ret)
return ret;
}
clk_rate = clk_get_rate(&clk);
if (!clk_rate)
return -EINVAL;
priv->usart_clk_rate = clk_rate;
clk_free(&clk);
return 0;
}
static int atmel_serial_probe(struct udevice *dev)
{
struct atmel_serial_platdata *plat = dev->platdata;
struct atmel_serial_priv *priv = dev_get_priv(dev);
int ret;
#if CONFIG_IS_ENABLED(OF_CONTROL)
fdt_addr_t addr_base;
addr_base = devfdt_get_addr(dev);
if (addr_base == FDT_ADDR_T_NONE)
return -ENODEV;
plat->base_addr = (uint32_t)addr_base;
#endif
priv->usart = (atmel_usart3_t *)plat->base_addr;
ret = atmel_serial_enable_clk(dev);
if (ret)
return ret;
_atmel_serial_init(priv->usart, priv->usart_clk_rate, gd->baudrate);
return 0;
}
#if CONFIG_IS_ENABLED(OF_CONTROL)
static const struct udevice_id atmel_serial_ids[] = {
{
.compatible = "atmel,at91sam9260-dbgu",
.data = CLK_TYPE_DBGU,
},
{
.compatible = "atmel,at91sam9260-usart",
.data = CLK_TYPE_NORMAL,
},
{ }
};
#endif
U_BOOT_DRIVER(serial_atmel) = {
.name = "serial_atmel",
.id = UCLASS_SERIAL,
#if CONFIG_IS_ENABLED(OF_CONTROL)
.of_match = atmel_serial_ids,
.platdata_auto_alloc_size = sizeof(struct atmel_serial_platdata),
#endif
.probe = atmel_serial_probe,
.ops = &atmel_serial_ops,
.flags = DM_FLAG_PRE_RELOC,
.priv_auto_alloc_size = sizeof(struct atmel_serial_priv),
};
#endif
#ifdef CONFIG_DEBUG_UART_ATMEL
static inline void _debug_uart_init(void)
{
atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_DEBUG_UART_BASE;
_atmel_serial_init(usart, CONFIG_DEBUG_UART_CLOCK, CONFIG_BAUDRATE);
}
static inline void _debug_uart_putc(int ch)
{
atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_DEBUG_UART_BASE;
while (!(readl(&usart->csr) & USART3_BIT(TXRDY)))
;
writel(ch, &usart->thr);
}
DEBUG_UART_FUNCS
#endif