amba: add pl011

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Andrea GALLO <andrea.gallo@stericsson.com>
Cc: Gael SALLES <gael.salles@stericsson.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

3 files changed, 202 insertions, 0 deletions

diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 8a5056bc69..c7ea2d974d 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -4,6 +4,15 @@ config DRIVER_SERIAL_ARM_DCC
 	depends on ARM
 	bool "ARM Debug Communications Channel (DCC) serial driver"
 
+config SERIAL_AMBA_PL011
+	bool "ARM AMBA PL011 serial port support"
+	depends on ARM_AMBA
+	help
+	  This selects the ARM(R) AMBA(R) PrimeCell PL011 UART.  If you have
+	  an Integrator/PP2, Integrator/CP or Versatile platform, say Y here.
+
+	  If unsure, say N.
+
 config DRIVER_SERIAL_IMX
 	depends on ARCH_IMX
 	default y
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 9f203bbc06..959290e642 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -5,6 +5,7 @@
 # serial_pl010.o
 # serial_xuartlite.o
 obj-$(CONFIG_DRIVER_SERIAL_ARM_DCC)		+= arm_dcc.o
+obj-$(CONFIG_SERIAL_AMBA_PL011) += amba-pl011.o
 obj-$(CONFIG_DRIVER_SERIAL_IMX)			+= serial_imx.o
 obj-$(CONFIG_DRIVER_SERIAL_ATMEL)		+= atmel.o
 obj-$(CONFIG_DRIVER_SERIAL_NETX)		+= serial_netx.o
diff --git a/drivers/serial/amba-pl011.c b/drivers/serial/amba-pl011.c
new file mode 100644
index 0000000000..07508d03b0
--- /dev/null
+++ b/drivers/serial/amba-pl011.c
@@ -0,0 +1,192 @@
+/*
+ * (C) Copyright 2000
+ * Rob Taylor, Flying Pig Systems. robt@flyingpig.com.
+ *
+ * (C) Copyright 2004
+ * ARM Ltd.
+ * Philippe Robin, <philippe.robin@arm.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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
+ */
+
+/* Simple U-Boot driver for the PrimeCell PL010/PL011 UARTs */
+
+#include <common.h>
+#include <driver.h>
+#include <init.h>
+#include <malloc.h>
+#include <asm/io.h>
+#include <linux/amba/serial.h>
+#include <linux/clk.h>
+
+/*
+ * We wrap our port structure around the generic console_device.
+ */
+struct amba_uart_port {
+	struct console_device	uart;		/* uart */
+	struct clk		*clk;		/* uart clock */
+	u32			uartclk;
+};
+
+static inline struct amba_uart_port *
+to_amba_uart_port(struct console_device *uart)
+{
+	return container_of(uart, struct amba_uart_port, uart);
+}
+
+static int pl011_setbaudrate(struct console_device *cdev, int baudrate)
+{
+	struct device_d *dev = cdev->dev;
+	struct amba_uart_port *uart = to_amba_uart_port(cdev);
+	unsigned int temp;
+	unsigned int divider;
+	unsigned int remainder;
+	unsigned int fraction;
+
+	/*
+	 ** Set baud rate
+	 **
+	 ** IBRD = UART_CLK / (16 * BAUD_RATE)
+	 ** FBRD = ROUND((64 * MOD(UART_CLK,(16 * BAUD_RATE))) / (16 * BAUD_RATE))
+	 */
+	temp = 16 * baudrate;
+	divider = uart->uartclk / temp;
+	remainder = uart->uartclk % temp;
+	temp = (8 * remainder) / baudrate;
+	fraction = (temp >> 1) + (temp & 1);
+
+	writel(divider, dev->map_base + UART011_IBRD);
+	writel(fraction, dev->map_base + UART011_FBRD);
+
+	return 0;
+}
+
+static void pl011_putc(struct console_device *cdev, char c)
+{
+	struct device_d *dev = cdev->dev;
+
+	/* Wait until there is space in the FIFO */
+	while (readl(dev->map_base + UART01x_FR) & UART01x_FR_TXFF);
+
+	/* Send the character */
+	writel(c, dev->map_base + UART01x_DR);
+}
+
+static int pl011_getc(struct console_device *cdev)
+{
+	struct device_d *dev = cdev->dev;
+	unsigned int data;
+
+	/* Wait until there is data in the FIFO */
+	while (readl(dev->map_base + UART01x_FR) & UART01x_FR_RXFE);
+
+	data = readl(dev->map_base + UART01x_DR);
+
+	/* Check for an error flag */
+	if (data & 0xffffff00) {
+		/* Clear the error */
+		writel(0xffffffff, dev->map_base + UART01x_ECR);
+		return -1;
+	}
+
+	return (int)data;
+}
+
+static int pl011_tstc(struct console_device *cdev)
+{
+	struct device_d *dev = cdev->dev;
+
+	return !(readl(dev->map_base + UART01x_FR) & UART01x_FR_RXFE);
+}
+
+int pl011_init_port (struct console_device *cdev)
+{
+	struct device_d *dev = cdev->dev;
+	struct amba_uart_port *uart = to_amba_uart_port(cdev);
+
+	/*
+	 ** First, disable everything.
+	 */
+	writel(0x0, dev->map_base + UART011_CR);
+
+	/*
+	 * Try to enable the clock producer.
+	 */
+	clk_enable(uart->clk);
+
+	uart->uartclk = clk_get_rate(uart->clk);
+
+	/*
+	 * set baud rate
+	 */
+	pl011_setbaudrate(cdev, 115200);
+	/*
+	 ** Set the UART to be 8 bits, 1 stop bit, no parity, fifo enabled.
+	 */
+	writel((UART01x_LCRH_WLEN_8 | UART01x_LCRH_FEN),
+	       dev->map_base + UART011_LCRH);
+
+	/*
+	 ** Finally, enable the UART
+	 */
+	writel((UART01x_CR_UARTEN | UART011_CR_TXE | UART011_CR_RXE),
+	       dev->map_base + UART011_CR);
+
+	return 0;
+}
+
+static int pl011_probe(struct device_d *dev)
+{
+	struct amba_uart_port *uart;
+	struct console_device *cdev;
+
+	uart = malloc(sizeof(struct amba_uart_port));
+
+	uart->clk = clk_get(dev, NULL);
+
+	cdev = &uart->uart;
+	dev->type_data = cdev;
+	cdev->dev = dev;
+	cdev->f_caps = CONSOLE_STDIN | CONSOLE_STDOUT | CONSOLE_STDERR;
+	cdev->tstc = pl011_tstc;
+	cdev->putc = pl011_putc;
+	cdev->getc = pl011_getc;
+	cdev->setbrg = pl011_setbaudrate;
+
+	pl011_init_port(cdev);
+
+	/* Enable UART */
+
+	console_register(cdev);
+
+	return 0;
+}
+
+static struct driver_d pl011_driver = {
+	.name = "uart-pl011",
+	.probe = pl011_probe,
+};
+
+static int pl011_init(void)
+{
+	register_driver(&pl011_driver);
+	return 0;
+}
+
+console_initcall(pl011_init);