diff options
Diffstat (limited to 'arch/arm/mach-lpc32xx/serial.c')
| -rw-r--r-- | arch/arm/mach-lpc32xx/serial.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/arch/arm/mach-lpc32xx/serial.c b/arch/arm/mach-lpc32xx/serial.c new file mode 100644 index 000000000..3e765c4bf --- /dev/null +++ b/arch/arm/mach-lpc32xx/serial.c @@ -0,0 +1,147 @@ +// 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 "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); +} |