serial: add UniPhier serial driver

The driver for on-chip UART used on Panasonic UniPhier platform.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>

drivers/serial/Makefile

@@ -39,6 +39,7 @@ obj-$(CONFIG_FSL_LPUART) += serial_lpuart.o
 obj-$(CONFIG_MXS_AUART) += mxs_auart.o
 obj-$(CONFIG_ARC_SERIAL) += serial_arc.o
 obj-$(CONFIG_TEGRA_SERIAL) += serial_tegra.o
+obj-$(CONFIG_UNIPHIER_SERIAL) += serial_uniphier.o
 
 ifndef CONFIG_SPL_BUILD
 obj-$(CONFIG_USB_TTY) += usbtty.o

drivers/serial/serial.c

@@ -157,6 +157,7 @@ serial_initfunc(sh_serial_initialize);
 serial_initfunc(arm_dcc_initialize);
 serial_initfunc(mxs_auart_initialize);
 serial_initfunc(arc_serial_initialize);
+serial_initfunc(uniphier_serial_initialize);
 
 /**
  * serial_register() - Register serial driver with serial driver core
@@ -250,6 +251,7 @@ void serial_initialize(void)
 	arm_dcc_initialize();
 	mxs_auart_initialize();
 	arc_serial_initialize();
+	uniphier_serial_initialize();
 
 	serial_assign(default_serial_console()->name);
 }

drivers/serial/serial_uniphier.c

@@ -0,0 +1,204 @@
+/*
+ * Copyright (C) 2012-2014 Panasonic Corporation
+ *   Author: Masahiro Yamada <yamada.m@jp.panasonic.com>
+ *
+ * Based on serial_ns16550.c
+ * (C) Copyright 2000
+ * Rob Taylor, Flying Pig Systems. robt@flyingpig.com.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <serial.h>
+
+#define UART_REG(x)					\
+	u8 x;						\
+	u8 postpad_##x[3];
+
+/*
+ * Note: Register map is slightly different from that of 16550.
+ */
+struct uniphier_serial {
+	UART_REG(rbr);		/* 0x00 */
+	UART_REG(ier);		/* 0x04 */
+	UART_REG(iir);		/* 0x08 */
+	UART_REG(fcr);		/* 0x0c */
+	u8 mcr;			/* 0x10 */
+	u8 lcr;
+	u16 __postpad;
+	UART_REG(lsr);		/* 0x14 */
+	UART_REG(msr);		/* 0x18 */
+	u32 __none1;
+	u32 __none2;
+	u16 dlr;
+	u16 __postpad2;
+};
+
+#define thr rbr
+
+/*
+ * These are the definitions for the Line Control Register
+ */
+#define UART_LCR_WLS_8	0x03		/* 8 bit character length */
+
+/*
+ * These are the definitions for the Line Status Register
+ */
+#define UART_LSR_DR	0x01		/* Data ready */
+#define UART_LSR_THRE	0x20		/* Xmit holding register empty */
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static void uniphier_serial_init(struct uniphier_serial *port)
+{
+	const unsigned int mode_x_div = 16;
+	unsigned int divisor;
+
+	writeb(UART_LCR_WLS_8, &port->lcr);
+
+	divisor = DIV_ROUND_CLOSEST(CONFIG_SYS_UNIPHIER_UART_CLK,
+						mode_x_div * gd->baudrate);
+
+	writew(divisor, &port->dlr);
+}
+
+static void uniphier_serial_setbrg(struct uniphier_serial *port)
+{
+	uniphier_serial_init(port);
+}
+
+static int uniphier_serial_tstc(struct uniphier_serial *port)
+{
+	return (readb(&port->lsr) & UART_LSR_DR) != 0;
+}
+
+static int uniphier_serial_getc(struct uniphier_serial *port)
+{
+	while (!uniphier_serial_tstc(port))
+		;
+
+	return readb(&port->rbr);
+}
+
+static void uniphier_serial_putc(struct uniphier_serial *port, const char c)
+{
+	if (c == '\n')
+		uniphier_serial_putc(port, '\r');
+
+	while (!(readb(&port->lsr) & UART_LSR_THRE))
+		;
+
+	writeb(c, &port->thr);
+}
+
+static struct uniphier_serial *serial_ports[4] = {
+#ifdef CONFIG_SYS_UNIPHIER_SERIAL_BASE0
+	(struct uniphier_serial *)CONFIG_SYS_UNIPHIER_SERIAL_BASE0,
+#else
+	NULL,
+#endif
+#ifdef CONFIG_SYS_UNIPHIER_SERIAL_BASE1
+	(struct uniphier_serial *)CONFIG_SYS_UNIPHIER_SERIAL_BASE1,
+#else
+	NULL,
+#endif
+#ifdef CONFIG_SYS_UNIPHIER_SERIAL_BASE2
+	(struct uniphier_serial *)CONFIG_SYS_UNIPHIER_SERIAL_BASE2,
+#else
+	NULL,
+#endif
+#ifdef CONFIG_SYS_UNIPHIER_SERIAL_BASE3
+	(struct uniphier_serial *)CONFIG_SYS_UNIPHIER_SERIAL_BASE3,
+#else
+	NULL,
+#endif
+};
+
+/* Multi serial device functions */
+#define DECLARE_ESERIAL_FUNCTIONS(port) \
+	static int  eserial##port##_init(void) \
+	{ \
+		uniphier_serial_init(serial_ports[port]); \
+		return 0 ; \
+	} \
+	static void eserial##port##_setbrg(void) \
+	{ \
+		uniphier_serial_setbrg(serial_ports[port]); \
+	} \
+	static int  eserial##port##_getc(void) \
+	{ \
+		return uniphier_serial_getc(serial_ports[port]); \
+	} \
+	static int  eserial##port##_tstc(void) \
+	{ \
+		return uniphier_serial_tstc(serial_ports[port]); \
+	} \
+	static void eserial##port##_putc(const char c) \
+	{ \
+		uniphier_serial_putc(serial_ports[port], c); \
+	}
+
+/* Serial device descriptor */
+#define INIT_ESERIAL_STRUCTURE(port, __name) {	\
+	.name	= __name,			\
+	.start	= eserial##port##_init,		\
+	.stop	= NULL,				\
+	.setbrg	= eserial##port##_setbrg,	\
+	.getc	= eserial##port##_getc,		\
+	.tstc	= eserial##port##_tstc,		\
+	.putc	= eserial##port##_putc,		\
+	.puts	= default_serial_puts,		\
+}
+
+#if defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE0)
+DECLARE_ESERIAL_FUNCTIONS(0);
+struct serial_device uniphier_serial0_device =
+	INIT_ESERIAL_STRUCTURE(0, "ttyS0");
+#endif
+#if defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE1)
+DECLARE_ESERIAL_FUNCTIONS(1);
+struct serial_device uniphier_serial1_device =
+	INIT_ESERIAL_STRUCTURE(1, "ttyS1");
+#endif
+#if defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE2)
+DECLARE_ESERIAL_FUNCTIONS(2);
+struct serial_device uniphier_serial2_device =
+	INIT_ESERIAL_STRUCTURE(2, "ttyS2");
+#endif
+#if defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE3)
+DECLARE_ESERIAL_FUNCTIONS(3);
+struct serial_device uniphier_serial3_device =
+	INIT_ESERIAL_STRUCTURE(3, "ttyS3");
+#endif
+
+__weak struct serial_device *default_serial_console(void)
+{
+#if defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE0)
+	return &uniphier_serial0_device;
+#elif defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE1)
+	return &uniphier_serial1_device;
+#elif defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE2)
+	return &uniphier_serial2_device;
+#elif defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE3)
+	return &uniphier_serial3_device;
+#else
+#error "No uniphier serial ports configured."
+#endif
+}
+
+void uniphier_serial_initialize(void)
+{
+#if defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE0)
+	serial_register(&uniphier_serial0_device);
+#endif
+#if defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE1)
+	serial_register(&uniphier_serial1_device);
+#endif
+#if defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE2)
+	serial_register(&uniphier_serial2_device);
+#endif
+#if defined(CONFIG_SYS_UNIPHIER_SERIAL_BASE3)
+	serial_register(&uniphier_serial3_device);
+#endif
+}