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authorKyösti Mälkki <kyosti.malkki@gmail.com>2014-01-30 15:45:16 +0200
committerKyösti Mälkki <kyosti.malkki@gmail.com>2014-03-04 15:34:27 +0100
commitbea6bf07dfd9b97ad81fb7433464a9f61ff02105 (patch)
tree10b6a471dcf8e63e313f3a0763316417b43649c5 /src/drivers/uart/uart8250mem.c
parent2b95da01e6bbdd8b001fa1ff2830dbaa70f14c3e (diff)
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uart8250: Move under drivers/uart
Change-Id: Ic65ffaaa092330ed68d891e4a09a8b86cdc04a3a Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com> Reviewed-on: http://review.coreboot.org/5236 Tested-by: build bot (Jenkins)
Diffstat (limited to 'src/drivers/uart/uart8250mem.c')
-rw-r--r--src/drivers/uart/uart8250mem.c133
1 files changed, 133 insertions, 0 deletions
diff --git a/src/drivers/uart/uart8250mem.c b/src/drivers/uart/uart8250mem.c
new file mode 100644
index 000000000..74929f592
--- /dev/null
+++ b/src/drivers/uart/uart8250mem.c
@@ -0,0 +1,133 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2003 Eric Biederman
+ * Copyright (C) 2006-2010 coresystems GmbH
+ *
+ * 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; version 2 of the License.
+ *
+ * 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 St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <arch/io.h>
+#include <console/uart.h>
+#include <device/device.h>
+#include <delay.h>
+#include "uart8250reg.h"
+
+/* Should support 8250, 16450, 16550, 16550A type UARTs */
+
+/* Expected character delay at 1200bps is 9ms for a working UART
+ * and no flow-control. Assume UART as stuck if shift register
+ * or FIFO takes more than 50ms per character to appear empty.
+ */
+#define SINGLE_CHAR_TIMEOUT (50 * 1000)
+#define FIFO_TIMEOUT (16 * SINGLE_CHAR_TIMEOUT)
+
+static int uart8250_mem_can_tx_byte(unsigned base_port)
+{
+ return read8(base_port + UART_LSR) & UART_LSR_THRE;
+}
+
+static void uart8250_mem_tx_byte(unsigned base_port, unsigned char data)
+{
+ unsigned long int i = SINGLE_CHAR_TIMEOUT;
+ while(i-- && !uart8250_mem_can_tx_byte(base_port))
+ udelay(1);
+ write8(base_port + UART_TBR, data);
+}
+
+static void uart8250_mem_tx_flush(unsigned base_port)
+{
+ unsigned long int i = FIFO_TIMEOUT;
+ while(i-- && !(read8(base_port + UART_LSR) & UART_LSR_TEMT))
+ udelay(1);
+}
+
+static int uart8250_mem_can_rx_byte(unsigned base_port)
+{
+ return read8(base_port + UART_LSR) & UART_LSR_DR;
+}
+
+static unsigned char uart8250_mem_rx_byte(unsigned base_port)
+{
+ unsigned long int i = SINGLE_CHAR_TIMEOUT;
+ while(i-- && !uart8250_mem_can_rx_byte(base_port))
+ udelay(1);
+ if (i)
+ return read8(base_port + UART_RBR);
+ else
+ return 0x0;
+}
+
+static void uart8250_mem_init(unsigned base_port, unsigned divisor)
+{
+ /* Disable interrupts */
+ write8(base_port + UART_IER, 0x0);
+ /* Enable FIFOs */
+ write8(base_port + UART_FCR, UART_FCR_FIFO_EN);
+
+ /* Assert DTR and RTS so the other end is happy */
+ write8(base_port + UART_MCR, UART_MCR_DTR | UART_MCR_RTS);
+
+ /* DLAB on */
+ write8(base_port + UART_LCR, UART_LCR_DLAB | CONFIG_TTYS0_LCS);
+
+ write8(base_port + UART_DLL, divisor & 0xFF);
+ write8(base_port + UART_DLM, (divisor >> 8) & 0xFF);
+
+ /* Set to 3 for 8N1 */
+ write8(base_port + UART_LCR, CONFIG_TTYS0_LCS);
+}
+
+void uart_init(void)
+{
+ u32 base = uart_platform_base(0);
+ if (!base)
+ return;
+
+ unsigned int div;
+ div = uart_baudrate_divisor(default_baudrate(), uart_platform_refclk(), 16);
+ uart8250_mem_init(base, div);
+}
+
+void uart_tx_byte(unsigned char data)
+{
+ u32 base = uart_platform_base(0);
+ if (!base)
+ return;
+ uart8250_mem_tx_byte(base, data);
+}
+
+unsigned char uart_rx_byte(void)
+{
+ u32 base = uart_platform_base(0);
+ if (!base)
+ return 0xff;
+ return uart8250_mem_rx_byte(base);
+}
+
+int uart_can_rx_byte(void)
+{
+ u32 base = uart_platform_base(0);
+ if (!base)
+ return 0;
+ return uart8250_mem_can_rx_byte(base);
+}
+
+void uart_tx_flush(void)
+{
+ u32 base = uart_platform_base(0);
+ if (!base)
+ return;
+ uart8250_mem_tx_flush(base);
+}