[U-Boot] [PATCH 3/6] S5PC100: serial driver for SMDKC100 support

[HeungJun Kim]

This patch is the serial driver for S5PC100 & SMDKC100.

Signed-off-by: HeungJun, Kim <riverful.kim at samsung.com>

---

 drivers/serial/Makefile         |    1 +
 drivers/serial/serial_s5pc100.c |  179 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 180 insertions(+), 0 deletions(-)
 create mode 100644 drivers/serial/serial_s5pc100.c

diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 64882a2..3334442 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -49,6 +49,7 @@ COBJS-$(CONFIG_PXA_SERIAL) += serial_pxa.o
 COBJS-$(CONFIG_SA1100_SERIAL) += serial_sa1100.o
 COBJS-$(CONFIG_S3C24X0_SERIAL) += serial_s3c24x0.o
 COBJS-$(CONFIG_S3C44B0_SERIAL) += serial_s3c44b0.o
+COBJS-$(CONFIG_S5PC100_SERIAL) += serial_s5pc100.o
 COBJS-$(CONFIG_XILINX_UARTLITE) += serial_xuartlite.o
 COBJS-$(CONFIG_SCIF_CONSOLE) += serial_sh.o
 COBJS-$(CONFIG_USB_TTY) += usbtty.o
diff --git a/drivers/serial/serial_s5pc100.c b/drivers/serial/serial_s5pc100.c
new file mode 100644
index 0000000..9394e77
--- /dev/null
+++ b/drivers/serial/serial_s5pc100.c
@@ -0,0 +1,179 @@
+/*
+ * (C) Copyright 2009
+ * Inki Dae, SAMSUNG Electronics, <inki.dae at samsung.com>
+ * Heungjun Kim, SAMSUNG Electronics, <riverful.kim at samsung.com>
+ * Minkyu Kang, SAMSUNG Electronics, <mk7.kang at samsung.com>
+ *
+ * (C) Copyright 2002
+ * Gary Jennejohn, DENX Software Engineering, <gj at denx.de>
+ *
+ * (C) Copyright 2008
+ * Guennadi Liakhovetki, DENX Software Engineering, <lg at denx.de>
+ *
+ * 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>
+
+#ifdef CONFIG_SERIAL0
+#define UART_NR	S5PC1XX_UART0
+#elif defined(CONFIG_SERIAL1)
+#define UART_NR	S5PC1XX_UART1
+#elif defined(CONFIG_SERIAL2)
+#define UART_NR	S5PC1XX_UART2
+#elif defined(CONFIG_SERIAL3)
+#define UART_NR	S5PC1XX_UART3
+#else
+#error "Bad: you didn't configure serial ..."
+#endif
+
+#define barrier() asm volatile("" ::: "memory")
+
+static inline s5pc1xx_uart_t *s5pc1xx_get_base_uart(enum s5pc1xx_uarts_nr nr)
+{
+	return (s5pc1xx_uart_t *)(S5P_UART_BASE + (nr * 0x400));
+}
+
+/*
+ * 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(void)
+{
+	DECLARE_GLOBAL_DATA_PTR;
+	s5pc1xx_uart_t *const uart = s5pc1xx_get_base_uart(UART_NR);
+	u32 pclk = get_PCLK();
+	u32 baudrate = gd->baudrate;
+	int i;
+
+	i = (pclk / baudrate) % 16;
+
+	uart->UBRDIV = pclk / baudrate / 16 - 1;
+	uart->UDIVSLOT = udivslot[i];
+
+	for (i = 0; i < 100; i++);
+		barrier();
+}
+
+/*
+ * 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(void)
+{
+	s5pc1xx_uart_t *const uart = s5pc1xx_get_base_uart(UART_NR);
+
+	/* reset and enable FIFOs, set triggers to the maximum */
+	uart->UFCON = 0;
+	uart->UMCON = 0;
+	/* 8N1 */
+	uart->ULCON = 0x3;
+	/* No interrupts, no DMA, pure polling */
+	uart->UCON = 0x245;
+
+	serial_setbrg();
+
+	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(void)
+{
+	s5pc1xx_uart_t *const uart = s5pc1xx_get_base_uart(UART_NR);
+
+	/* wait for character to arrive */
+	while (!(uart->UTRSTAT & 0x1));
+
+	return uart->URXH & 0xff;
+}
+
+#ifdef CONFIG_MODEM_SUPPORT
+static int be_quiet;
+void disable_putc(void)
+{
+	be_quiet = 1;
+}
+
+void enable_putc(void)
+{
+	be_quiet = 0;
+}
+#endif
+
+
+/*
+ * Output a single byte to the serial port.
+ */
+void serial_putc(const char c)
+{
+	s5pc1xx_uart_t *const uart = s5pc1xx_get_base_uart(UART_NR);
+
+#ifdef CONFIG_MODEM_SUPPORT
+	if (be_quiet)
+		return;
+#endif
+
+	/* wait for room in the tx FIFO */
+	while (!(uart->UTRSTAT & 0x2));
+
+	uart->UTXH = c;
+
+	/* If \n, also do \r */
+	if (c == '\n')
+		serial_putc('\r');
+}
+
+/*
+ * Test whether a character is in the RX buffer
+ */
+int serial_tstc(void)
+{
+	s5pc1xx_uart_t *const uart = s5pc1xx_get_base_uart(UART_NR);
+
+	return uart->UTRSTAT & 0x1;
+}
+
+void serial_puts(const char *s)
+{
+	while (*s)
+		serial_putc(*s++);
+}
-- 
1.5.6.3