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