[U-Boot] [PATCH 3/4 v4] s5pc1xx: support serial driver

[Minkyu Kang <mk7.kang@samsung.com>]

This patch includes the serial driver for s5pc1xx.
s5pc1xx uart driver needs own register setting and clock configuration.
So, need to special driver.

Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
---
Changes since v1:
- use serial multi API
- use writel/readl function
- remove duplicate code

Changes since v2:
- use sizeof() instead of the constant

Changes since v3:
- fix the commit log
- fix the style
- remove unnecessary codes
- add error check logic in while loop

 common/serial.c                 |   18 ++++
 drivers/serial/Makefile         |    1 +
 drivers/serial/serial_s5pc1xx.c |  195 +++++++++++++++++++++++++++++++++++++++
 include/serial.h                |    7 ++
 4 files changed, 221 insertions(+), 0 deletions(-)
 create mode 100644 drivers/serial/serial_s5pc1xx.c

diff --git a/common/serial.c b/common/serial.c
index 41a24c2..e5ce9fd 100644
--- a/common/serial.c
+++ b/common/serial.c
@@ -69,6 +69,18 @@ struct serial_device *__default_serial_console (void)
 #else
 #error "CONFIG_SERIAL? missing."
 #endif
+#elif defined(CONFIG_S5PC1XX)
+#if defined(CONFIG_SERIAL0)
+	return &s5pc1xx_serial0_device;
+#elif defined(CONFIG_SERIAL1)
+	return &s5pc1xx_serial1_device;
+#elif defined(CONFIG_SERIAL2)
+	return &s5pc1xx_serial2_device;
+#elif defined(CONFIG_SERIAL3)
+	return &s5pc1xx_serial3_device;
+#else
+#error "CONFIG_SERIAL? missing."
+#endif
 #elif defined(CONFIG_OMAP3_ZOOM2)
 		return ZOOM2_DEFAULT_SERIAL_DEVICE;
 #else
@@ -139,6 +151,12 @@ void serial_initialize (void)
 	serial_register(&s3c24xx_serial1_device);
 	serial_register(&s3c24xx_serial2_device);
 #endif
+#if defined(CONFIG_S5PC1XX)
+	serial_register(&s5pc1xx_serial0_device);
+	serial_register(&s5pc1xx_serial1_device);
+	serial_register(&s5pc1xx_serial2_device);
+	serial_register(&s5pc1xx_serial3_device);
+#endif
 	serial_assign (default_serial_console ()->name);
 }
 
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 64882a2..3c77a7c 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -33,6 +33,7 @@ COBJS-$(CONFIG_NS9750_UART) += ns9750_serial.o
 COBJS-$(CONFIG_SYS_NS16550) += ns16550.o
 COBJS-$(CONFIG_DRIVER_S3C4510_UART) += s3c4510b_uart.o
 COBJS-$(CONFIG_S3C64XX) += s3c64xx.o
+COBJS-$(CONFIG_S5PC1XX) += serial_s5pc1xx.o
 COBJS-$(CONFIG_SYS_NS16550_SERIAL) += serial.o
 COBJS-$(CONFIG_CLPS7111_SERIAL) += serial_clps7111.o
 COBJS-$(CONFIG_IMX_SERIAL) += serial_imx.o
diff --git a/drivers/serial/serial_s5pc1xx.c b/drivers/serial/serial_s5pc1xx.c
new file mode 100644
index 0000000..64c1dcc
--- /dev/null
+++ b/drivers/serial/serial_s5pc1xx.c
@@ -0,0 +1,195 @@
+/*
+ * (C) Copyright 2009 SAMSUNG Electronics
+ * Minkyu Kang <mk7.kang@samsung.com>
+ * Heungjun Kim <riverful.kim@samsung.com>
+ *
+ * based on drivers/serial/s3c64xx.c
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/arch/uart.h>
+#include <asm/arch/clk.h>
+#include <serial.h>
+
+static inline struct s5pc1xx_uart *s5pc1xx_get_base_uart(int dev_index)
+{
+	u32 offset = dev_index * sizeof(struct s5pc1xx_uart);
+
+	if (cpu_is_s5pc100())
+		return (struct s5pc1xx_uart *)(S5PC100_UART_BASE + offset);
+	else
+		return (struct s5pc1xx_uart *)(S5PC110_UART_BASE + offset);
+}
+
+/*
+ * The coefficient, used to calculate the baudrate on S5PC1XX UARTs is
+ * calculated as
+ * C = UBRDIV * 16 + number_of_set_bits_in_UDIVSLOT
+ * however, section 31.6.11 of the datasheet doesn't recomment using 1 for 1,
+ * 3 for 2, ... (2^n - 1) for n, instead, they suggest using these constants:
+ */
+static const int udivslot[] = {
+	0,
+	0x0080,
+	0x0808,
+	0x0888,
+	0x2222,
+	0x4924,
+	0x4a52,
+	0x54aa,
+	0x5555,
+	0xd555,
+	0xd5d5,
+	0xddd5,
+	0xdddd,
+	0xdfdd,
+	0xdfdf,
+	0xffdf,
+};
+
+void serial_setbrg_dev(const int dev_index)
+{
+	DECLARE_GLOBAL_DATA_PTR;
+	struct s5pc1xx_uart *const uart = s5pc1xx_get_base_uart(dev_index);
+	u32 pclk = get_pclk();
+	u32 baudrate = gd->baudrate;
+	u32 val;
+
+	val = pclk / baudrate;
+
+	writel(val / 16 - 1, &uart->ubrdiv);
+	writel(udivslot[val % 16], &uart->udivslot);
+}
+
+/*
+ * Initialise the serial port with the given baudrate. The settings
+ * are always 8 data bits, no parity, 1 stop bit, no start bits.
+ */
+int serial_init_dev(const int dev_index)
+{
+	struct s5pc1xx_uart *const uart = s5pc1xx_get_base_uart(dev_index);
+
+	/* reset and enable FIFOs, set triggers to the maximum */
+	writel(0, &uart->ufcon);
+	writel(0, &uart->umcon);
+	/* 8N1 */
+	writel(0x3, &uart->ulcon);
+	/* No interrupts, no DMA, pure polling */
+	writel(0x245, &uart->ucon);
+
+	serial_setbrg_dev(dev_index);
+
+	return 0;
+}
+
+static int serial_err_check(const int dev_index)
+{
+	struct s5pc1xx_uart *const uart = s5pc1xx_get_base_uart(dev_index);
+
+	if (readl(&uart->uerstat) & 0xf)
+		return 1;
+
+	return 0;
+}
+
+/*
+ * Read a single byte from the serial port. Returns 1 on success, 0
+ * otherwise. When the function is succesfull, the character read is
+ * written into its argument c.
+ */
+int serial_getc_dev(const int dev_index)
+{
+	struct s5pc1xx_uart *const uart = s5pc1xx_get_base_uart(dev_index);
+
+	/* wait for character to arrive */
+	while (!(readl(&uart->utrstat) & 0x1)) {
+		if (serial_err_check(dev_index))
+			return 0;
+	}
+
+	return (int)(readl(&uart->urxh) & 0xff);
+}
+
+/*
+ * Output a single byte to the serial port.
+ */
+void serial_putc_dev(const char c, const int dev_index)
+{
+	struct s5pc1xx_uart *const uart = s5pc1xx_get_base_uart(dev_index);
+
+	/* wait for room in the tx FIFO */
+	while (!(readl(&uart->utrstat) & 0x2)) {
+		if (serial_err_check(dev_index))
+			return;
+	}
+
+	writel(c, &uart->utxh);
+
+	/* If \n, also do \r */
+	if (c == '\n')
+		serial_putc('\r');
+}
+
+/*
+ * Test whether a character is in the RX buffer
+ */
+int serial_tstc_dev(const int dev_index)
+{
+	struct s5pc1xx_uart *const uart = s5pc1xx_get_base_uart(dev_index);
+
+	return (int)(readl(&uart->utrstat) & 0x1);
+}
+
+void serial_puts_dev(const char *s, const int dev_index)
+{
+	while (*s)
+		serial_putc_dev(*s++, dev_index);
+}
+
+/* Multi serial device functions */
+#define DECLARE_S5P_SERIAL_FUNCTIONS(port) \
+int s5p_serial##port##_init(void) { return serial_init_dev(port); } \
+void s5p_serial##port##_setbrg(void) { serial_setbrg_dev(port); } \
+int s5p_serial##port##_getc(void) { return serial_getc_dev(port); } \
+int s5p_serial##port##_tstc(void) { return serial_tstc_dev(port); } \
+void s5p_serial##port##_putc(const char c) { serial_putc_dev(c, port); } \
+void s5p_serial##port##_puts(const char *s) { serial_puts_dev(s, port); }
+
+#define INIT_S5P_SERIAL_STRUCTURE(port, name, bus) { \
+	name, \
+	bus, \
+	s5p_serial##port##_init, \
+	s5p_serial##port##_setbrg, \
+	s5p_serial##port##_getc, \
+	s5p_serial##port##_tstc, \
+	s5p_serial##port##_putc, \
+	s5p_serial##port##_puts, }
+
+DECLARE_S5P_SERIAL_FUNCTIONS(0);
+struct serial_device s5pc1xx_serial0_device =
+	INIT_S5P_SERIAL_STRUCTURE(0, "s5pser0", "S5PUART0");
+DECLARE_S5P_SERIAL_FUNCTIONS(1);
+struct serial_device s5pc1xx_serial1_device =
+	INIT_S5P_SERIAL_STRUCTURE(1, "s5pser1", "S5PUART1");
+DECLARE_S5P_SERIAL_FUNCTIONS(2);
+struct serial_device s5pc1xx_serial2_device =
+	INIT_S5P_SERIAL_STRUCTURE(2, "s5pser2", "S5PUART2");
+DECLARE_S5P_SERIAL_FUNCTIONS(3);
+struct serial_device s5pc1xx_serial3_device =
+	INIT_S5P_SERIAL_STRUCTURE(3, "s5pser3", "S5PUART3");
diff --git a/include/serial.h b/include/serial.h
index 821b583..bbda3f0 100644
--- a/include/serial.h
+++ b/include/serial.h
@@ -43,6 +43,13 @@ extern struct serial_device s3c24xx_serial1_device;
 extern struct serial_device s3c24xx_serial2_device;
 #endif
 
+#if defined(CONFIG_S5PC1XX)
+extern struct serial_device s5pc1xx_serial0_device;
+extern struct serial_device s5pc1xx_serial1_device;
+extern struct serial_device s5pc1xx_serial2_device;
+extern struct serial_device s5pc1xx_serial3_device;
+#endif
+
 #if defined(CONFIG_OMAP3_ZOOM2)
 extern struct serial_device zoom2_serial_device0;
 extern struct serial_device zoom2_serial_device1;
-- 
1.5.4.3