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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* arch/arm/mach-lpc32xx/serial.c
*
* Author: Kevin Wells <kevin.wells@nxp.com>
*
* Copyright (C) 2010 NXP Semiconductors
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/serial.h>
#include <linux/serial_core.h>
#include <linux/serial_reg.h>
#include <linux/serial_8250.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/soc/nxp/lpc32xx-misc.h>
#include "lpc32xx.h"
#include "common.h"
#define LPC32XX_SUART_FIFO_SIZE 64
struct uartinit {
char *uart_ck_name;
u32 ck_mode_mask;
void __iomem *pdiv_clk_reg;
resource_size_t mapbase;
};
static struct uartinit uartinit_data[] __initdata = {
{
.uart_ck_name = "uart5_ck",
.ck_mode_mask =
LPC32XX_UART_CLKMODE_LOAD(LPC32XX_UART_CLKMODE_ON, 5),
.pdiv_clk_reg = LPC32XX_CLKPWR_UART5_CLK_CTRL,
.mapbase = LPC32XX_UART5_BASE,
},
{
.uart_ck_name = "uart3_ck",
.ck_mode_mask =
LPC32XX_UART_CLKMODE_LOAD(LPC32XX_UART_CLKMODE_ON, 3),
.pdiv_clk_reg = LPC32XX_CLKPWR_UART3_CLK_CTRL,
.mapbase = LPC32XX_UART3_BASE,
},
{
.uart_ck_name = "uart4_ck",
.ck_mode_mask =
LPC32XX_UART_CLKMODE_LOAD(LPC32XX_UART_CLKMODE_ON, 4),
.pdiv_clk_reg = LPC32XX_CLKPWR_UART4_CLK_CTRL,
.mapbase = LPC32XX_UART4_BASE,
},
{
.uart_ck_name = "uart6_ck",
.ck_mode_mask =
LPC32XX_UART_CLKMODE_LOAD(LPC32XX_UART_CLKMODE_ON, 6),
.pdiv_clk_reg = LPC32XX_CLKPWR_UART6_CLK_CTRL,
.mapbase = LPC32XX_UART6_BASE,
},
};
/* LPC3250 Errata HSUART.1: Hang workaround via loopback mode on inactivity */
void lpc32xx_loopback_set(resource_size_t mapbase, int state)
{
int bit;
u32 tmp;
switch (mapbase) {
case LPC32XX_HS_UART1_BASE:
bit = 0;
break;
case LPC32XX_HS_UART2_BASE:
bit = 1;
break;
case LPC32XX_HS_UART7_BASE:
bit = 6;
break;
default:
WARN(1, "lpc32xx_hs: Warning: Unknown port at %08x\n", mapbase);
return;
}
tmp = readl(LPC32XX_UARTCTL_CLOOP);
if (state)
tmp |= (1 << bit);
else
tmp &= ~(1 << bit);
writel(tmp, LPC32XX_UARTCTL_CLOOP);
}
EXPORT_SYMBOL_GPL(lpc32xx_loopback_set);
void __init lpc32xx_serial_init(void)
{
u32 tmp, clkmodes = 0;
struct clk *clk;
unsigned int puart;
int i, j;
for (i = 0; i < ARRAY_SIZE(uartinit_data); i++) {
clk = clk_get(NULL, uartinit_data[i].uart_ck_name);
if (!IS_ERR(clk)) {
clk_enable(clk);
}
/* Setup UART clock modes for all UARTs, disable autoclock */
clkmodes |= uartinit_data[i].ck_mode_mask;
/* pre-UART clock divider set to 1 */
__raw_writel(0x0101, uartinit_data[i].pdiv_clk_reg);
/*
* Force a flush of the RX FIFOs to work around a
* HW bug
*/
puart = uartinit_data[i].mapbase;
__raw_writel(0xC1, LPC32XX_UART_IIR_FCR(puart));
__raw_writel(0x00, LPC32XX_UART_DLL_FIFO(puart));
j = LPC32XX_SUART_FIFO_SIZE;
while (j--)
tmp = __raw_readl(
LPC32XX_UART_DLL_FIFO(puart));
__raw_writel(0, LPC32XX_UART_IIR_FCR(puart));
}
/* This needs to be done after all UART clocks are setup */
__raw_writel(clkmodes, LPC32XX_UARTCTL_CLKMODE);
for (i = 0; i < ARRAY_SIZE(uartinit_data); i++) {
/* Force a flush of the RX FIFOs to work around a HW bug */
puart = uartinit_data[i].mapbase;
__raw_writel(0xC1, LPC32XX_UART_IIR_FCR(puart));
__raw_writel(0x00, LPC32XX_UART_DLL_FIFO(puart));
j = LPC32XX_SUART_FIFO_SIZE;
while (j--)
tmp = __raw_readl(LPC32XX_UART_DLL_FIFO(puart));
__raw_writel(0, LPC32XX_UART_IIR_FCR(puart));
}
/* Disable IrDA pulsing support on UART6 */
tmp = __raw_readl(LPC32XX_UARTCTL_CTRL);
tmp |= LPC32XX_UART_UART6_IRDAMOD_BYPASS;
__raw_writel(tmp, LPC32XX_UARTCTL_CTRL);
/* Disable UART5->USB transparent mode or USB won't work */
tmp = __raw_readl(LPC32XX_UARTCTL_CTRL);
tmp &= ~LPC32XX_UART_U5_ROUTE_TO_USB;
__raw_writel(tmp, LPC32XX_UARTCTL_CTRL);
}