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-rw-r--r--arch/arm/mach-lpc32xx/serial.c148
1 files changed, 148 insertions, 0 deletions
diff --git a/arch/arm/mach-lpc32xx/serial.c b/arch/arm/mach-lpc32xx/serial.c
new file mode 100644
index 0000000000..3b1203db81
--- /dev/null
+++ b/arch/arm/mach-lpc32xx/serial.c
@@ -0,0 +1,148 @@
+// 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);
+}