u-boot/drivers/serial/serial_linflexuart.c

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/*
* (C) Copyright 2013-2016 Freescale Semiconductor, Inc.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <watchdog.h>
#include <asm/io.h>
#include <serial.h>
#include <linux/compiler.h>
#include <asm/arch/imx-regs.h>
#include <asm/arch/clock.h>
#define US1_TDRE (1 << 7)
#define US1_RDRF (1 << 5)
#define UC2_TE (1 << 3)
#define LINCR1_INIT (1 << 0)
#define LINCR1_MME (1 << 4)
#define LINCR1_BF (1 << 7)
#define LINSR_LINS_INITMODE (0x00001000)
#define LINSR_LINS_MASK (0x0000F000)
#define UARTCR_UART (1 << 0)
#define UARTCR_WL0 (1 << 1)
#define UARTCR_PCE (1 << 2)
#define UARTCR_PC0 (1 << 3)
#define UARTCR_TXEN (1 << 4)
#define UARTCR_RXEN (1 << 5)
#define UARTCR_PC1 (1 << 6)
#define UARTSR_DTF (1 << 1)
#define UARTSR_DRF (1 << 2)
#define UARTSR_RMB (1 << 9)
DECLARE_GLOBAL_DATA_PTR;
#ifndef CONFIG_DM_SERIAL
#error "The linflex serial driver does not have non-DM support."
#endif
static void _linflex_serial_setbrg(struct linflex_fsl *base, int baudrate)
{
u32 clk = mxc_get_clock(MXC_UART_CLK);
u32 ibr, fbr;
if (!baudrate)
baudrate = CONFIG_BAUDRATE;
ibr = (u32) (clk / (16 * gd->baudrate));
fbr = (u32) (clk % (16 * gd->baudrate)) * 16;
__raw_writel(ibr, &base->linibrr);
__raw_writel(fbr, &base->linfbrr);
}
static int _linflex_serial_getc(struct linflex_fsl *base)
{
char c;
if (!(__raw_readb(&base->uartsr) & UARTSR_DRF))
return -EAGAIN;
if (!(__raw_readl(&base->uartsr) & UARTSR_RMB))
return -EAGAIN;
c = __raw_readl(&base->bdrm);
__raw_writeb((__raw_readb(&base->uartsr) | (UARTSR_DRF | UARTSR_RMB)),
&base->uartsr);
return c;
}
static int _linflex_serial_putc(struct linflex_fsl *base, const char c)
{
__raw_writeb(c, &base->bdrl);
if (!(__raw_readb(&base->uartsr) & UARTSR_DTF))
return -EAGAIN;
__raw_writeb((__raw_readb(&base->uartsr) | UARTSR_DTF), &base->uartsr);
return 0;
}
/*
* Initialise the serial port with the given baudrate. The settings
* are always 8 data bits, no parity, 1 stop bit, no start bits.
*/
static int _linflex_serial_init(struct linflex_fsl *base)
{
volatile u32 ctrl;
/* set the Linflex in master mode amd activate by-pass filter */
ctrl = LINCR1_BF | LINCR1_MME;
__raw_writel(ctrl, &base->lincr1);
/* init mode */
ctrl |= LINCR1_INIT;
__raw_writel(ctrl, &base->lincr1);
/* waiting for init mode entry - TODO: add a timeout */
while ((__raw_readl(&base->linsr) & LINSR_LINS_MASK) !=
LINSR_LINS_INITMODE);
/* set UART bit to allow writing other bits */
__raw_writel(UARTCR_UART, &base->uartcr);
/* provide data bits, parity, stop bit, etc */
serial_setbrg();
/* 8 bit data, no parity, Tx and Rx enabled, UART mode */
__raw_writel(UARTCR_PC1 | UARTCR_RXEN | UARTCR_TXEN | UARTCR_PC0
| UARTCR_WL0 | UARTCR_UART, &base->uartcr);
ctrl = __raw_readl(&base->lincr1);
ctrl &= ~LINCR1_INIT;
__raw_writel(ctrl, &base->lincr1); /* end init mode */
return 0;
}
struct linflex_serial_platdata {
struct linflex_fsl *base_addr;
u8 port_id; /* do we need this? */
};
struct linflex_serial_priv {
struct linflex_fsl *lfuart;
};
int linflex_serial_setbrg(struct udevice *dev, int baudrate)
{
struct linflex_serial_priv *priv = dev_get_priv(dev);
_linflex_serial_setbrg(priv->lfuart, baudrate);
return 0;
}
static int linflex_serial_getc(struct udevice *dev)
{
struct linflex_serial_priv *priv = dev_get_priv(dev);
return _linflex_serial_getc(priv->lfuart);
}
static int linflex_serial_putc(struct udevice *dev, const char ch)
{
struct linflex_serial_priv *priv = dev_get_priv(dev);
return _linflex_serial_putc(priv->lfuart, ch);
}
static int linflex_serial_pending(struct udevice *dev, bool input)
{
struct linflex_serial_priv *priv = dev_get_priv(dev);
uint32_t uartsr = __raw_readl(&priv->lfuart->uartsr);
if (input)
return ((uartsr & UARTSR_DRF) && (uartsr & UARTSR_RMB)) ? 1 : 0;
else
return uartsr & UARTSR_DTF ? 0 : 1;
}
static void linflex_serial_init_internal(struct linflex_fsl *lfuart)
{
_linflex_serial_init(lfuart);
_linflex_serial_setbrg(lfuart, CONFIG_BAUDRATE);
return;
}
static int linflex_serial_probe(struct udevice *dev)
{
struct linflex_serial_platdata *plat = dev->platdata;
struct linflex_serial_priv *priv = dev_get_priv(dev);
priv->lfuart = (struct linflex_fsl *)plat->base_addr;
linflex_serial_init_internal(priv->lfuart);
return 0;
}
static const struct dm_serial_ops linflex_serial_ops = {
.putc = linflex_serial_putc,
.pending = linflex_serial_pending,
.getc = linflex_serial_getc,
.setbrg = linflex_serial_setbrg,
};
U_BOOT_DRIVER(serial_linflex) = {
.name = "serial_linflex",
.id = UCLASS_SERIAL,
.probe = linflex_serial_probe,
.ops = &linflex_serial_ops,
.flags = DM_FLAG_PRE_RELOC,
.priv_auto_alloc_size = sizeof(struct linflex_serial_priv),
};
#ifdef CONFIG_DEBUG_UART_LINFLEXUART
#include <debug_uart.h>
static inline void _debug_uart_init(void)
{
struct linflex_fsl *base = (struct linflex_fsl *)CONFIG_DEBUG_UART_BASE;
linflex_serial_init_internal(base);
}
static inline void _debug_uart_putc(int ch)
{
struct linflex_fsl *base = (struct linflex_fsl *)CONFIG_DEBUG_UART_BASE;
/* XXX: Is this OK? Should this use the non-DM version? */
_linflex_serial_putc(base, ch);
}
DEBUG_UART_FUNCS
#endif /* CONFIG_DEBUG_UART_LINFLEXUART */