linux/arch/arm/mach-lpc32xx/serial.c

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/*
* arch/arm/mach-lpc32xx/serial.c
*
* Author: Kevin Wells <kevin.wells@nxp.com>
*
* Copyright (C) 2010 NXP Semiconductors
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#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 <mach/hardware.h>
#include <mach/platform.h>
#include "common.h"
#define LPC32XX_SUART_FIFO_SIZE 64
/* Standard 8250/16550 compatible serial ports */
static struct plat_serial8250_port serial_std_platform_data[] = {
#ifdef CONFIG_ARCH_LPC32XX_UART5_SELECT
{
.membase = io_p2v(LPC32XX_UART5_BASE),
.mapbase = LPC32XX_UART5_BASE,
.irq = IRQ_LPC32XX_UART_IIR5,
.uartclk = LPC32XX_MAIN_OSC_FREQ,
.regshift = 2,
.iotype = UPIO_MEM32,
.flags = UPF_BOOT_AUTOCONF | UPF_BUGGY_UART |
UPF_SKIP_TEST,
},
#endif
#ifdef CONFIG_ARCH_LPC32XX_UART3_SELECT
{
.membase = io_p2v(LPC32XX_UART3_BASE),
.mapbase = LPC32XX_UART3_BASE,
.irq = IRQ_LPC32XX_UART_IIR3,
.uartclk = LPC32XX_MAIN_OSC_FREQ,
.regshift = 2,
.iotype = UPIO_MEM32,
.flags = UPF_BOOT_AUTOCONF | UPF_BUGGY_UART |
UPF_SKIP_TEST,
},
#endif
#ifdef CONFIG_ARCH_LPC32XX_UART4_SELECT
{
.membase = io_p2v(LPC32XX_UART4_BASE),
.mapbase = LPC32XX_UART4_BASE,
.irq = IRQ_LPC32XX_UART_IIR4,
.uartclk = LPC32XX_MAIN_OSC_FREQ,
.regshift = 2,
.iotype = UPIO_MEM32,
.flags = UPF_BOOT_AUTOCONF | UPF_BUGGY_UART |
UPF_SKIP_TEST,
},
#endif
#ifdef CONFIG_ARCH_LPC32XX_UART6_SELECT
{
.membase = io_p2v(LPC32XX_UART6_BASE),
.mapbase = LPC32XX_UART6_BASE,
.irq = IRQ_LPC32XX_UART_IIR6,
.uartclk = LPC32XX_MAIN_OSC_FREQ,
.regshift = 2,
.iotype = UPIO_MEM32,
.flags = UPF_BOOT_AUTOCONF | UPF_BUGGY_UART |
UPF_SKIP_TEST,
},
#endif
{ },
};
struct uartinit {
char *uart_ck_name;
u32 ck_mode_mask;
void __iomem *pdiv_clk_reg;
};
static struct uartinit uartinit_data[] __initdata = {
#ifdef CONFIG_ARCH_LPC32XX_UART5_SELECT
{
.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,
},
#endif
#ifdef CONFIG_ARCH_LPC32XX_UART3_SELECT
{
.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,
},
#endif
#ifdef CONFIG_ARCH_LPC32XX_UART4_SELECT
{
.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,
},
#endif
#ifdef CONFIG_ARCH_LPC32XX_UART6_SELECT
{
.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,
},
#endif
};
static struct platform_device serial_std_platform_device = {
.name = "serial8250",
.id = 0,
.dev = {
.platform_data = serial_std_platform_data,
},
};
static struct platform_device *lpc32xx_serial_devs[] __initdata = {
&serial_std_platform_device,
};
void __init lpc32xx_serial_init(void)
{
u32 tmp, clkmodes = 0;
struct clk *clk;
unsigned int puart;
int i, j;
/* UART clocks are off, let clock driver manage them */
__raw_writel(0, LPC32XX_CLKPWR_UART_CLK_CTRL);
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);
serial_std_platform_data[i].uartclk =
clk_get_rate(clk);
}
/* Fall back on main osc rate if clock rate return fails */
if (serial_std_platform_data[i].uartclk == 0)
serial_std_platform_data[i].uartclk =
LPC32XX_MAIN_OSC_FREQ;
/* 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);
}
/* 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) - 1; i++) {
/* Force a flush of the RX FIFOs to work around a HW bug */
puart = serial_std_platform_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 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);
platform_add_devices(lpc32xx_serial_devs,
ARRAY_SIZE(lpc32xx_serial_devs));
}