serial: add LPC32X0 high-speed UART devices support

This change adds an implementation of high-speed UART found on NXP
LPC32X0 SoCs. Such UARTs are enumerated as UART1, UART2 and UART7.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
Acked-by: Marek Vasut <marek.vasut@gmail.com>

1 files changed, 112 insertions, 0 deletions

diff --git a/drivers/serial/lpc32xx_hsuart.c b/drivers/serial/lpc32xx_hsuart.c
new file mode 100644
index 00000000000..8ce3382d869
--- /dev/null
+++ b/drivers/serial/lpc32xx_hsuart.c
@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2011 Vladimir Zapolskiy <vz@mleia.com>
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#include <common.h>
+#include <asm/arch/cpu.h>
+#include <asm/arch/clk.h>
+#include <asm/arch/uart.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static struct hsuart_regs *hsuart = (struct hsuart_regs *)HS_UART_BASE;
+
+static void lpc32xx_hsuart_set_baudrate(void)
+{
+	u32 div;
+
+	/* UART rate = PERIPH_CLK / ((HSU_RATE + 1) x 14) */
+	div = (get_serial_clock() / 14 + gd->baudrate / 2) / gd->baudrate - 1;
+	if (div > 255)
+		div = 255;
+
+	writel(div, &hsuart->rate);
+}
+
+static int lpc32xx_hsuart_getc(void)
+{
+	while (!(readl(&hsuart->level) & HSUART_LEVEL_RX))
+		/* NOP */;
+
+	return readl(&hsuart->rx) & HSUART_RX_DATA;
+}
+
+static void lpc32xx_hsuart_putc(const char c)
+{
+	writel(c, &hsuart->tx);
+
+	/* Wait for character to be sent */
+	while (readl(&hsuart->level) & HSUART_LEVEL_TX)
+		/* NOP */;
+}
+
+static int lpc32xx_hsuart_tstc(void)
+{
+	if (readl(&hsuart->level) & HSUART_LEVEL_RX)
+		return 1;
+
+	return 0;
+}
+
+static void lpc32xx_hsuart_init(void)
+{
+	lpc32xx_hsuart_set_baudrate();
+
+	/* Disable hardware RTS and CTS flow control, set up RX and TX FIFO */
+	writel(HSUART_CTRL_TMO_16 | HSUART_CTRL_HSU_OFFSET(20) |
+	       HSUART_CTRL_HSU_RX_TRIG_32 | HSUART_CTRL_HSU_TX_TRIG_0,
+	       &hsuart->ctrl);
+}
+
+void serial_setbrg(void)
+{
+	return lpc32xx_hsuart_set_baudrate();
+}
+
+void serial_putc(const char c)
+{
+	lpc32xx_hsuart_putc(c);
+
+	/* If \n, also do \r */
+	if (c == '\n')
+		lpc32xx_hsuart_putc('\r');
+}
+
+int serial_getc(void)
+{
+	return lpc32xx_hsuart_getc();
+}
+
+void serial_puts(const char *s)
+{
+	while (*s)
+		serial_putc(*s++);
+}
+
+int serial_tstc(void)
+{
+	return lpc32xx_hsuart_tstc();
+}
+
+int serial_init(void)
+{
+	lpc32xx_hsuart_init();
+
+	return 0;
+}