diff mbox

[v6] tty: serial: add Freescale lpuart driver support

Message ID 1370309270-21019-1-git-send-email-b35083@freescale.com (mailing list archive)
State New, archived
Headers show

Commit Message

Lu Jingchang June 4, 2013, 1:27 a.m. UTC
Add Freescale lpuart driver support. The lpuart device
can be found on Vybrid VF610 and Layerscape LS-1 SoCs.

Signed-off-by: Jingchang Lu <b35083@freescale.com>
---
changes in v6:
  Enable being built as a module support.

changes in v5:
 Coding style fix, remove redundant code.
 Checking clk_prepare_enable return value.
 Using devm_ioremap_resource instead of devm_request_and_ioremap.

changes in v4:
 Change Vybrid VF610 SoC compatible string to "fsl,vf610-lpuart"

changes in v3:
 Use general driver name lpuart instead of mvf for further share between SoCs.
 Add bind doc in Documentation/devicetree/bindings/tty/serial.
 Remove unused #include header lines and clean up code.

changes in v2:
 Remove unused variables and clean up the code.

 .../devicetree/bindings/tty/serial/fsl-lpuart.txt  |  14 +
 drivers/tty/serial/Kconfig                         |  14 +
 drivers/tty/serial/Makefile                        |   1 +
 drivers/tty/serial/fsl_lpuart.c                    | 873 +++++++++++++++++++++
 include/uapi/linux/serial_core.h                   |   3 +
 5 files changed, 905 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/tty/serial/fsl-lpuart.txt
 create mode 100644 drivers/tty/serial/fsl_lpuart.c

Comments

Fabio Estevam June 4, 2013, 2:54 a.m. UTC | #1
On Mon, Jun 3, 2013 at 10:27 PM, Jingchang Lu <b35083@freescale.com> wrote:

> +config SERIAL_FSL_LPUART
> +       tristate "Freescale lpuart serial port support"
> +       select SERIAL_CORE
> +       help
> +         Support for the on-chip lpuart on some Freescale SOCs.
> +
> +config SERIAL_FSL_LPUART_CONSOLE
> +       bool "Console on Freescale lpuart serial port"

It is better yo use tristate here as well.

I have just sent the same fix for imx serial.

Keeping it bool may lead to build error when SERIAL_FSL_LPUART=m and
SERIAL_FSL_LPUART_CONSOLE=y

Regards,

Fabio Estevam
Lu Jingchang June 4, 2013, 3:02 a.m. UTC | #2
>-----Original Message-----
>From: Fabio Estevam [mailto:festevam@gmail.com]
>Sent: Tuesday, June 04, 2013 10:55 AM
>To: Lu Jingchang-B35083
>Cc: linux-serial@vger.kernel.org; gregkh@linuxfoundation.org;
>s.hauer@pengutronix.de; shawn.guo@linaro.org; linux-arm-
>kernel@lists.infradead.org
>Subject: Re: [PATCH v6] tty: serial: add Freescale lpuart driver support
>
>On Mon, Jun 3, 2013 at 10:27 PM, Jingchang Lu <b35083@freescale.com> wrote:
>
>> +config SERIAL_FSL_LPUART
>> +       tristate "Freescale lpuart serial port support"
>> +       select SERIAL_CORE
>> +       help
>> +         Support for the on-chip lpuart on some Freescale SOCs.
>> +
>> +config SERIAL_FSL_LPUART_CONSOLE
>> +       bool "Console on Freescale lpuart serial port"
>
>It is better yo use tristate here as well.
>
>I have just sent the same fix for imx serial.
>
>Keeping it bool may lead to build error when SERIAL_FSL_LPUART=m and
>SERIAL_FSL_LPUART_CONSOLE=y
[Lu Jingchang-B35083] 
  SERIAL_FSL_LPUART_CONSOLE depends on SERIAL_FSL_LPUART=y in the patch as below, when SERIAL_FSL_LPUART is configured as module, it can't be configured as console. Thanks!

+config SERIAL_FSL_LPUART_CONSOLE
+       bool "Console on Freescale lpuart serial port"
+       depends on SERIAL_FSL_LPUART=y
Fabio Estevam June 4, 2013, 3:08 a.m. UTC | #3
On Tue, Jun 4, 2013 at 12:02 AM, Lu Jingchang-B35083
<B35083@freescale.com> wrote:

> [Lu Jingchang-B35083]
>   SERIAL_FSL_LPUART_CONSOLE depends on SERIAL_FSL_LPUART=y in the patch as below, when SERIAL_FSL_LPUART is configured as module, it can't be configured as console. Thanks!

Why to prevent using the console of the driver is built as module?
Fabio Estevam June 4, 2013, 3:08 a.m. UTC | #4
On Tue, Jun 4, 2013 at 12:08 AM, Fabio Estevam <festevam@gmail.com> wrote:
> On Tue, Jun 4, 2013 at 12:02 AM, Lu Jingchang-B35083
> <B35083@freescale.com> wrote:
>
>> [Lu Jingchang-B35083]
>>   SERIAL_FSL_LPUART_CONSOLE depends on SERIAL_FSL_LPUART=y in the patch as below, when SERIAL_FSL_LPUART is configured as module, it can't be configured as console. Thanks!
>
> Why to prevent using the console of the driver is built as module?

I meant "if the driver is built as module"
Lu Jingchang June 4, 2013, 3:37 a.m. UTC | #5
>-----Original Message-----
>From: Fabio Estevam [mailto:festevam@gmail.com]
>Sent: Tuesday, June 04, 2013 11:09 AM
>To: Lu Jingchang-B35083
>Cc: linux-serial@vger.kernel.org; gregkh@linuxfoundation.org;
>s.hauer@pengutronix.de; shawn.guo@linaro.org; linux-arm-
>kernel@lists.infradead.org
>Subject: Re: [PATCH v6] tty: serial: add Freescale lpuart driver support
>
>On Tue, Jun 4, 2013 at 12:08 AM, Fabio Estevam <festevam@gmail.com> wrote:
>> On Tue, Jun 4, 2013 at 12:02 AM, Lu Jingchang-B35083
>> <B35083@freescale.com> wrote:
>>
>>> [Lu Jingchang-B35083]
>>>   SERIAL_FSL_LPUART_CONSOLE depends on SERIAL_FSL_LPUART=y in the patch
>as below, when SERIAL_FSL_LPUART is configured as module, it can't be
>configured as console. Thanks!
>>
>> Why to prevent using the console of the driver is built as module?
>
>I meant "if the driver is built as module"
[Lu Jingchang-B35083] 
In serial driver imx.c, when CONFIG_SERIAL_IMX_CONSOLE=m, does the code between #ifdef CONFIG_SERIAL_IMX_CONSOLE ... #else be compiled?
Thanks!
Lu Jingchang June 4, 2013, 4:55 a.m. UTC | #6
>-----Original Message-----
>From: Fabio Estevam [mailto:festevam@gmail.com]
>Sent: Tuesday, June 04, 2013 11:09 AM
>To: Lu Jingchang-B35083
>Cc: linux-serial@vger.kernel.org; gregkh@linuxfoundation.org;
>s.hauer@pengutronix.de; shawn.guo@linaro.org; linux-arm-
>kernel@lists.infradead.org
>Subject: Re: [PATCH v6] tty: serial: add Freescale lpuart driver support
>
>On Tue, Jun 4, 2013 at 12:08 AM, Fabio Estevam <festevam@gmail.com> wrote:
>> On Tue, Jun 4, 2013 at 12:02 AM, Lu Jingchang-B35083
>> <B35083@freescale.com> wrote:
>>
>>> [Lu Jingchang-B35083]
>>>   SERIAL_FSL_LPUART_CONSOLE depends on SERIAL_FSL_LPUART=y in the patch
>as below, when SERIAL_FSL_LPUART is configured as module, it can't be
>configured as console. Thanks!
>>
>> Why to prevent using the console of the driver is built as module?
>
>I meant "if the driver is built as module"
[Lu Jingchang-B35083] 
  From your patch of " serial: imx: Allow module build", I think the code between #ifdef CONFIG_SERIAL_IMX_CONSOLE ... #else in imx.c won't be built because the configuration is CONFIG_SERIAL_IMX_CONSOLE_MODULE now. So it is the same as if disable CONFIG_SERIAL_IMX_CONSOLE when built the driver as a module, isn't it?
 On other hand, if enable CONFIG_SERIAL_X_CONSOLE option when the driver is configured as module, the build will fail with message like ERROR: "uart_console_device" [drivers/tty/serial/**.ko] undefined! Stephen Rothwel gives the solution once at url:
http://www.linuxhorizon.com/9-linux/42b33a65f64d95a2.htm
  I have checked drivers/tty/serial/Kconfig to make sure that other serial drivers indeed did this way. 
  Thanks!
Fabio Estevam June 4, 2013, 5:06 a.m. UTC | #7
On Tue, Jun 4, 2013 at 1:55 AM, Lu Jingchang-B35083
<B35083@freescale.com> wrote:

>   From your patch of " serial: imx: Allow module build", I think the code between #ifdef CONFIG_SERIAL_IMX_CONSOLE ... #else in imx.c won't be built because the configuration is CONFIG_SERIAL_IMX_CONSOLE_MODULE now. So it is the same as if disable CONFIG_SERIAL_IMX_CONSOLE when built the driver as a module, isn't it?
>  On other hand, if enable CONFIG_SERIAL_X_CONSOLE option when the driver is configured as module, the build will fail with message like ERROR: "uart_console_device" [drivers/tty/serial/**.ko] undefined! Stephen Rothwel gives the solution once at url:
> http://www.linuxhorizon.com/9-linux/42b33a65f64d95a2.htm
>   I have checked drivers/tty/serial/Kconfig to make sure that other serial drivers indeed did this way.

Maybe we need to use "#if IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE)"

I will resend the series tomorrow.

Thanks,

Fabio Estevam
Arnd Bergmann June 4, 2013, 9:11 a.m. UTC | #8
On Tuesday 04 June 2013 00:08:27 Fabio Estevam wrote:
> On Tue, Jun 4, 2013 at 12:02 AM, Lu Jingchang-B35083
> <B35083@freescale.com> wrote:
> 
> > [Lu Jingchang-B35083]
> >   SERIAL_FSL_LPUART_CONSOLE depends on SERIAL_FSL_LPUART=y in the patch as below, when SERIAL_FSL_LPUART is configured as module, it can't be configured as console. Thanks!
> 
> Why to prevent using the console of the driver is built as module?

All serial port drivers do this. IIRC the reason is that the console
has to be started from console_initcall(), which is not available in
modules.

	Arnd
Greg Kroah-Hartman June 6, 2013, 8:05 p.m. UTC | #9
On Tue, Jun 04, 2013 at 09:27:50AM +0800, Jingchang Lu wrote:
> Add Freescale lpuart driver support. The lpuart device
> can be found on Vybrid VF610 and Layerscape LS-1 SoCs.
> 
> Signed-off-by: Jingchang Lu <b35083@freescale.com>

This breaks the build on x86 systems with:
  CC [M]  drivers/tty/serial/fsl_lpuart.o
drivers/tty/serial/fsl_lpuart.c: In function ‘lpuart_probe’:
drivers/tty/serial/fsl_lpuart.c:751:2: error: implicit declaration of function ‘of_alias_get_id’ [-Werror=implicit-function-declaration]

so I can't take this :(

greg k-h
Fabio Estevam June 6, 2013, 11:06 p.m. UTC | #10
Hi Jingchang,

On Thu, Jun 6, 2013 at 5:05 PM, Greg KH <gregkh@linuxfoundation.org> wrote:
> On Tue, Jun 04, 2013 at 09:27:50AM +0800, Jingchang Lu wrote:
>> Add Freescale lpuart driver support. The lpuart device
>> can be found on Vybrid VF610 and Layerscape LS-1 SoCs.
>>
>> Signed-off-by: Jingchang Lu <b35083@freescale.com>
>
> This breaks the build on x86 systems with:
>   CC [M]  drivers/tty/serial/fsl_lpuart.o
> drivers/tty/serial/fsl_lpuart.c: In function ‘lpuart_probe’:
> drivers/tty/serial/fsl_lpuart.c:751:2: error: implicit declaration of function ‘of_alias_get_id’ [-Werror=implicit-function-declaration]
>
> so I can't take this :(

On imx serial driver this build error is avoided by protecting the
serial_imx_probe_dt() with "#ifdef CONFIG_OF" and you could so the
same on the fsl_lpaurt driver to avoid the build issue that Greg
reported.

Regards,

Fabio Estevam
Lu Jingchang June 7, 2013, 1:29 a.m. UTC | #11
>This breaks the build on x86 systems with:

>  CC [M]  drivers/tty/serial/fsl_lpuart.o

>drivers/tty/serial/fsl_lpuart.c: In function ‘lpuart_probe’:

>drivers/tty/serial/fsl_lpuart.c:751:2: error: implicit declaration of

>function ‘of_alias_get_id’ [-Werror=implicit-function-declaration]

>

[Lu Jingchang-B35083] 
I will send the v7 patch with this error fixed. Thanks!
Lu Jingchang June 7, 2013, 1:48 a.m. UTC | #12
>> This breaks the build on x86 systems with:

>>   CC [M]  drivers/tty/serial/fsl_lpuart.o

>> drivers/tty/serial/fsl_lpuart.c: In function ‘lpuart_probe’:

>> drivers/tty/serial/fsl_lpuart.c:751:2: error: implicit declaration of

>> function ‘of_alias_get_id’ [-Werror=implicit-function-declaration]

>>

>> so I can't take this :(

>

>On imx serial driver this build error is avoided by protecting the

>serial_imx_probe_dt() with "#ifdef CONFIG_OF" and you could so the same on

>the fsl_lpaurt driver to avoid the build issue that Greg reported.


[Lu Jingchang-B35083] 
  imx serial driver supports dt and non-dt uart device, "#ifdef CONFIG_OF" seems
to distinguish these, but fsl_lpuart only support dt device. 
  of_alias_get_id is defined in <linux/of.h>, it's referenced by <linux/of_device.h>
but with "#ifdef CONFIG_OF_DEVICE" restriction. So indirectly referencing "of.h" by
"of_device.h" without CONFIG_OF_DEVICE option will cause build error. Add direct
reference to "<linux/of.h>" in driver can resolve this error.
Thanks!
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/tty/serial/fsl-lpuart.txt b/Documentation/devicetree/bindings/tty/serial/fsl-lpuart.txt
new file mode 100644
index 0000000..6fd1dd1
--- /dev/null
+++ b/Documentation/devicetree/bindings/tty/serial/fsl-lpuart.txt
@@ -0,0 +1,14 @@ 
+* Freescale low power universal asynchronous receiver/transmitter (lpuart)
+
+Required properties:
+- compatible : Should be "fsl,<soc>-lpuart"
+- reg : Address and length of the register set for the device
+- interrupts : Should contain uart interrupt
+
+Example:
+
+uart0: serial@40027000 {
+	       compatible = "fsl,vf610-lpuart";
+	       reg = <0x40027000 0x1000>;
+	       interrupts = <0 61 0x00>;
+       };
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 7e7006f..8b756a8 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1484,6 +1484,20 @@  config SERIAL_RP2_NR_UARTS
 	  If multiple cards are present, the default limit of 32 ports may
 	  need to be increased.
 
+config SERIAL_FSL_LPUART
+	tristate "Freescale lpuart serial port support"
+	select SERIAL_CORE
+	help
+	  Support for the on-chip lpuart on some Freescale SOCs.
+
+config SERIAL_FSL_LPUART_CONSOLE
+	bool "Console on Freescale lpuart serial port"
+	depends on SERIAL_FSL_LPUART=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  If you have enabled the lpuart serial port on the Freescale SoCs,
+	  you can make it the console by answering Y to this option.
+
 endmenu
 
 endif # TTY
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index eedfec4..cf650f0 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -85,3 +85,4 @@  obj-$(CONFIG_SERIAL_AR933X)   += ar933x_uart.o
 obj-$(CONFIG_SERIAL_EFM32_UART) += efm32-uart.o
 obj-$(CONFIG_SERIAL_ARC)	+= arc_uart.o
 obj-$(CONFIG_SERIAL_RP2)	+= rp2.o
+obj-$(CONFIG_SERIAL_FSL_LPUART)	+= fsl_lpuart.o
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
new file mode 100644
index 0000000..267718c
--- /dev/null
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -0,0 +1,873 @@ 
+/*
+ *  Freescale lpuart serial port driver
+ *
+ *  Copyright 2012-2013 Freescale Semiconductor, Inc.
+ *
+ * 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.
+ */
+
+#if defined(CONFIG_SERIAL_FSL_LPUART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/clk.h>
+#include <linux/of_device.h>
+#include <linux/console.h>
+#include <linux/serial_core.h>
+#include <linux/tty_flip.h>
+
+/* All registers are 8-bit width */
+#define UARTBDH			0x00
+#define UARTBDL			0x01
+#define UARTCR1			0x02
+#define UARTCR2			0x03
+#define UARTSR1			0x04
+#define UARTCR3			0x06
+#define UARTDR			0x07
+#define UARTCR4			0x0a
+#define UARTCR5			0x0b
+#define UARTMODEM		0x0d
+#define UARTPFIFO		0x10
+#define UARTCFIFO		0x11
+#define UARTSFIFO		0x12
+#define UARTTWFIFO		0x13
+#define UARTTCFIFO		0x14
+#define UARTRWFIFO		0x15
+
+#define UARTBDH_LBKDIE		0x80
+#define UARTBDH_RXEDGIE		0x40
+#define UARTBDH_SBR_MASK	0x1f
+
+#define UARTCR1_LOOPS		0x80
+#define UARTCR1_RSRC		0x20
+#define UARTCR1_M		0x10
+#define UARTCR1_WAKE		0x08
+#define UARTCR1_ILT		0x04
+#define UARTCR1_PE		0x02
+#define UARTCR1_PT		0x01
+
+#define UARTCR2_TIE		0x80
+#define UARTCR2_TCIE		0x40
+#define UARTCR2_RIE		0x20
+#define UARTCR2_ILIE		0x10
+#define UARTCR2_TE		0x08
+#define UARTCR2_RE		0x04
+#define UARTCR2_RWU		0x02
+#define UARTCR2_SBK		0x01
+
+#define UARTSR1_TDRE		0x80
+#define UARTSR1_TC		0x40
+#define UARTSR1_RDRF		0x20
+#define UARTSR1_IDLE		0x10
+#define UARTSR1_OR		0x08
+#define UARTSR1_NF		0x04
+#define UARTSR1_FE		0x02
+#define UARTSR1_PE		0x01
+
+#define UARTCR3_R8		0x80
+#define UARTCR3_T8		0x40
+#define UARTCR3_TXDIR		0x20
+#define UARTCR3_TXINV		0x10
+#define UARTCR3_ORIE		0x08
+#define UARTCR3_NEIE		0x04
+#define UARTCR3_FEIE		0x02
+#define UARTCR3_PEIE		0x01
+
+#define UARTCR4_MAEN1		0x80
+#define UARTCR4_MAEN2		0x40
+#define UARTCR4_M10		0x20
+#define UARTCR4_BRFA_MASK	0x1f
+#define UARTCR4_BRFA_OFF	0
+
+#define UARTCR5_TDMAS		0x80
+#define UARTCR5_RDMAS		0x20
+
+#define UARTMODEM_RXRTSE	0x08
+#define UARTMODEM_TXRTSPOL	0x04
+#define UARTMODEM_TXRTSE	0x02
+#define UARTMODEM_TXCTSE	0x01
+
+#define UARTPFIFO_TXFE		0x80
+#define UARTPFIFO_FIFOSIZE_MASK	0x7
+#define UARTPFIFO_TXSIZE_OFF	4
+#define UARTPFIFO_RXFE		0x08
+#define UARTPFIFO_RXSIZE_OFF	0
+
+#define UARTCFIFO_TXFLUSH	0x80
+#define UARTCFIFO_RXFLUSH	0x40
+#define UARTCFIFO_RXOFE		0x04
+#define UARTCFIFO_TXOFE		0x02
+#define UARTCFIFO_RXUFE		0x01
+
+#define UARTSFIFO_TXEMPT	0x80
+#define UARTSFIFO_RXEMPT	0x40
+#define UARTSFIFO_RXOF		0x04
+#define UARTSFIFO_TXOF		0x02
+#define UARTSFIFO_RXUF		0x01
+
+#define DRIVER_NAME	"fsl-lpuart"
+#define DEV_NAME	"ttyLP"
+#define UART_NR		6
+
+struct lpuart_port {
+	struct uart_port	port;
+	struct clk		*clk;
+	unsigned int		txfifo_size;
+	unsigned int		rxfifo_size;
+};
+
+static struct of_device_id lpuart_dt_ids[] = {
+	{
+		.compatible = "fsl,vf610-lpuart",
+	},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, lpuart_dt_ids);
+
+static void lpuart_stop_tx(struct uart_port *port)
+{
+	unsigned char temp;
+
+	temp = readb(port->membase + UARTCR2);
+	temp &= ~(UARTCR2_TIE | UARTCR2_TCIE);
+	writeb(temp, port->membase + UARTCR2);
+}
+
+static void lpuart_stop_rx(struct uart_port *port)
+{
+	unsigned char temp;
+
+	temp = readb(port->membase + UARTCR2);
+	writeb(temp & ~UARTCR2_RE, port->membase + UARTCR2);
+}
+
+static void lpuart_enable_ms(struct uart_port *port)
+{
+}
+
+static inline void lpuart_transmit_buffer(struct lpuart_port *sport)
+{
+	struct circ_buf *xmit = &sport->port.state->xmit;
+
+	while (!uart_circ_empty(xmit) &&
+		(readb(sport->port.membase + UARTTCFIFO) < sport->txfifo_size)) {
+		writeb(xmit->buf[xmit->tail], sport->port.membase + UARTDR);
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		sport->port.icount.tx++;
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&sport->port);
+
+	if (uart_circ_empty(xmit))
+		lpuart_stop_tx(&sport->port);
+}
+
+static void lpuart_start_tx(struct uart_port *port)
+{
+	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
+	unsigned char temp;
+
+	temp = readb(port->membase + UARTCR2);
+	writeb(temp | UARTCR2_TIE, port->membase + UARTCR2);
+
+	if (readb(port->membase + UARTSR1) & UARTSR1_TDRE)
+		lpuart_transmit_buffer(sport);
+}
+
+static irqreturn_t lpuart_txint(int irq, void *dev_id)
+{
+	struct lpuart_port *sport = dev_id;
+	struct circ_buf *xmit = &sport->port.state->xmit;
+	unsigned long flags;
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+	if (sport->port.x_char) {
+		writeb(sport->port.x_char, sport->port.membase + UARTDR);
+		goto out;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
+		lpuart_stop_tx(&sport->port);
+		goto out;
+	}
+
+	lpuart_transmit_buffer(sport);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&sport->port);
+
+out:
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t lpuart_rxint(int irq, void *dev_id)
+{
+	struct lpuart_port *sport = dev_id;
+	unsigned int flg, ignored = 0;
+	struct tty_port *port = &sport->port.state->port;
+	unsigned long flags;
+	unsigned char rx, sr;
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+
+	while (!(readb(sport->port.membase + UARTSFIFO) & UARTSFIFO_RXEMPT)) {
+		flg = TTY_NORMAL;
+		sport->port.icount.rx++;
+		/*
+		 * to clear the FE, OR, NF, FE, PE flags,
+		 * read SR1 then read DR
+		 */
+		sr = readb(sport->port.membase + UARTSR1);
+		rx = readb(sport->port.membase + UARTDR);
+
+		if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
+			continue;
+
+		if (sr & (UARTSR1_PE | UARTSR1_OR | UARTSR1_FE)) {
+			if (sr & UARTSR1_PE)
+				sport->port.icount.parity++;
+			else if (sr & UARTSR1_FE)
+				sport->port.icount.frame++;
+
+			if (sr & UARTSR1_OR)
+				sport->port.icount.overrun++;
+
+			if (sr & sport->port.ignore_status_mask) {
+				if (++ignored > 100)
+					goto out;
+				continue;
+			}
+
+			sr &= sport->port.read_status_mask;
+
+			if (sr & UARTSR1_PE)
+				flg = TTY_PARITY;
+			else if (sr & UARTSR1_FE)
+				flg = TTY_FRAME;
+
+			if (sr & UARTSR1_OR)
+				flg = TTY_OVERRUN;
+
+#ifdef SUPPORT_SYSRQ
+			sport->port.sysrq = 0;
+#endif
+		}
+
+		tty_insert_flip_char(port, rx, flg);
+	}
+
+out:
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+
+	tty_flip_buffer_push(port);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t lpuart_int(int irq, void *dev_id)
+{
+	struct lpuart_port *sport = dev_id;
+	unsigned char sts;
+
+	sts = readb(sport->port.membase + UARTSR1);
+
+	if (sts & UARTSR1_RDRF)
+		lpuart_rxint(irq, dev_id);
+
+	if (sts & UARTSR1_TDRE &&
+		!(readb(sport->port.membase + UARTCR5) & UARTCR5_TDMAS))
+		lpuart_txint(irq, dev_id);
+
+	return IRQ_HANDLED;
+}
+
+/* return TIOCSER_TEMT when transmitter is not busy */
+static unsigned int lpuart_tx_empty(struct uart_port *port)
+{
+	return (readb(port->membase + UARTSR1) & UARTSR1_TC) ?
+		TIOCSER_TEMT : 0;
+}
+
+static unsigned int lpuart_get_mctrl(struct uart_port *port)
+{
+	unsigned int temp = 0;
+	unsigned char reg;
+
+	reg = readb(port->membase + UARTMODEM);
+	if (reg & UARTMODEM_TXCTSE)
+		temp |= TIOCM_CTS;
+
+	if (reg & UARTMODEM_RXRTSE)
+		temp |= TIOCM_RTS;
+
+	return temp;
+}
+
+static void lpuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	unsigned char temp;
+
+	temp = readb(port->membase + UARTMODEM) &
+			~(UARTMODEM_RXRTSE | UARTMODEM_TXCTSE);
+
+	if (mctrl & TIOCM_RTS)
+		temp |= UARTMODEM_RXRTSE;
+
+	if (mctrl & TIOCM_CTS)
+		temp |= UARTMODEM_TXCTSE;
+
+	writeb(temp, port->membase + UARTMODEM);
+}
+
+static void lpuart_break_ctl(struct uart_port *port, int break_state)
+{
+	unsigned char temp;
+
+	temp = readb(port->membase + UARTCR2) & ~UARTCR2_SBK;
+
+	if (break_state != 0)
+		temp |= UARTCR2_SBK;
+
+	writeb(temp, port->membase + UARTCR2);
+}
+
+static void lpuart_setup_watermark(struct lpuart_port *sport)
+{
+	unsigned char val, cr2;
+
+	cr2 = readb(sport->port.membase + UARTCR2);
+	cr2 &= ~(UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_TE |
+			UARTCR2_RIE | UARTCR2_RE);
+	writeb(cr2, sport->port.membase + UARTCR2);
+
+	/* determine FIFO size and enable FIFO mode */
+	val = readb(sport->port.membase + UARTPFIFO);
+
+	sport->txfifo_size = 0x1 << (((val >> UARTPFIFO_TXSIZE_OFF) &
+		UARTPFIFO_FIFOSIZE_MASK) + 1);
+
+	sport->rxfifo_size = 0x1 << (((val >> UARTPFIFO_RXSIZE_OFF) &
+		UARTPFIFO_FIFOSIZE_MASK) + 1);
+
+	writeb(val | UARTPFIFO_TXFE | UARTPFIFO_RXFE,
+			sport->port.membase + UARTPFIFO);
+
+	/* flush Tx and Rx FIFO */
+	writeb(UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH,
+			sport->port.membase + UARTCFIFO);
+
+	writeb(2, sport->port.membase + UARTTWFIFO);
+	writeb(1, sport->port.membase + UARTRWFIFO);
+}
+
+static int lpuart_startup(struct uart_port *port)
+{
+	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
+	int ret;
+	unsigned long flags;
+	unsigned char temp;
+
+	ret = devm_request_irq(port->dev, port->irq, lpuart_int, 0,
+				DRIVER_NAME, sport);
+	if (ret)
+		return ret;
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+
+	lpuart_setup_watermark(sport);
+
+	temp = readb(sport->port.membase + UARTCR2);
+	temp |= (UARTCR2_RIE | UARTCR2_TIE | UARTCR2_RE | UARTCR2_TE);
+	writeb(temp, sport->port.membase + UARTCR2);
+
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+	return 0;
+}
+
+static void lpuart_shutdown(struct uart_port *port)
+{
+	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
+	unsigned char temp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* disable Rx/Tx and interrupts */
+	temp = readb(port->membase + UARTCR2);
+	temp &= ~(UARTCR2_TE | UARTCR2_RE |
+			UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_RIE);
+	writeb(temp, port->membase + UARTCR2);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	devm_free_irq(port->dev, port->irq, sport);
+}
+
+static void
+lpuart_set_termios(struct uart_port *port, struct ktermios *termios,
+		   struct ktermios *old)
+{
+	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
+	unsigned long flags;
+	unsigned char cr1, old_cr1, old_cr2, cr4, bdh, modem;
+	unsigned int  baud;
+	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
+	unsigned int sbr, brfa;
+
+	cr1 = old_cr1 = readb(sport->port.membase + UARTCR1);
+	old_cr2 = readb(sport->port.membase + UARTCR2);
+	cr4 = readb(sport->port.membase + UARTCR4);
+	bdh = readb(sport->port.membase + UARTBDH);
+	modem = readb(sport->port.membase + UARTMODEM);
+	/*
+	 * only support CS8 and CS7, and for CS7 must enable PE.
+	 * supported mode:
+	 *  - (7,e/o,1)
+	 *  - (8,n,1)
+	 *  - (8,m/s,1)
+	 *  - (8,e/o,1)
+	 */
+	while ((termios->c_cflag & CSIZE) != CS8 &&
+		(termios->c_cflag & CSIZE) != CS7) {
+		termios->c_cflag &= ~CSIZE;
+		termios->c_cflag |= old_csize;
+		old_csize = CS8;
+	}
+
+	if ((termios->c_cflag & CSIZE) == CS8 ||
+		(termios->c_cflag & CSIZE) == CS7)
+		cr1 = old_cr1 & ~UARTCR1_M;
+
+	if (termios->c_cflag & CMSPAR) {
+		if ((termios->c_cflag & CSIZE) != CS8) {
+			termios->c_cflag &= ~CSIZE;
+			termios->c_cflag |= CS8;
+		}
+		cr1 |= UARTCR1_M;
+	}
+
+	if (termios->c_cflag & CRTSCTS) {
+		modem |= (UARTMODEM_RXRTSE | UARTMODEM_TXCTSE);
+	} else {
+		termios->c_cflag &= ~CRTSCTS;
+		modem &= ~(UARTMODEM_RXRTSE | UARTMODEM_TXCTSE);
+	}
+
+	if (termios->c_cflag & CSTOPB)
+		termios->c_cflag &= ~CSTOPB;
+
+	/* parity must be enabled when CS7 to match 8-bits format */
+	if ((termios->c_cflag & CSIZE) == CS7)
+		termios->c_cflag |= PARENB;
+
+	if ((termios->c_cflag & PARENB)) {
+		if (termios->c_cflag & CMSPAR) {
+			cr1 &= ~UARTCR1_PE;
+			cr1 |= UARTCR1_M;
+		} else {
+			cr1 |= UARTCR1_PE;
+			if ((termios->c_cflag & CSIZE) == CS8)
+				cr1 |= UARTCR1_M;
+			if (termios->c_cflag & PARODD)
+				cr1 |= UARTCR1_PT;
+			else
+				cr1 &= ~UARTCR1_PT;
+		}
+	}
+
+	/* ask the core to calculate the divisor */
+	baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+
+	sport->port.read_status_mask = 0;
+	if (termios->c_iflag & INPCK)
+		sport->port.read_status_mask |=	(UARTSR1_FE | UARTSR1_PE);
+	if (termios->c_iflag & (BRKINT | PARMRK))
+		sport->port.read_status_mask |= UARTSR1_FE;
+
+	/* characters to ignore */
+	sport->port.ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		sport->port.ignore_status_mask |= UARTSR1_PE;
+	if (termios->c_iflag & IGNBRK) {
+		sport->port.ignore_status_mask |= UARTSR1_FE;
+		/*
+		 * if we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			sport->port.ignore_status_mask |= UARTSR1_OR;
+	}
+
+	/* update the per-port timeout */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	/* wait transmit engin complete */
+	while (!(readb(sport->port.membase + UARTSR1) & UARTSR1_TC))
+		barrier();
+
+	/* disable transmit and receive */
+	writeb(old_cr2 & ~(UARTCR2_TE | UARTCR2_RE),
+			sport->port.membase + UARTCR2);
+
+	sbr = sport->port.uartclk / (16 * baud);
+	brfa = ((sport->port.uartclk - (16 * sbr * baud)) * 2) / baud;
+	bdh &= ~UARTBDH_SBR_MASK;
+	bdh |= (sbr >> 8) & 0x1F;
+	cr4 &= ~UARTCR4_BRFA_MASK;
+	brfa &= UARTCR4_BRFA_MASK;
+	writeb(cr4 | brfa, sport->port.membase + UARTCR4);
+	writeb(bdh, sport->port.membase + UARTBDH);
+	writeb(sbr & 0xFF, sport->port.membase + UARTBDL);
+	writeb(cr1, sport->port.membase + UARTCR1);
+	writeb(modem, sport->port.membase + UARTMODEM);
+
+	/* restore control register */
+	writeb(old_cr2, sport->port.membase + UARTCR2);
+
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+static const char *lpuart_type(struct uart_port *port)
+{
+	return "FSL_LPUART";
+}
+
+static void lpuart_release_port(struct uart_port *port)
+{
+	/* nothing to do */
+}
+
+static int lpuart_request_port(struct uart_port *port)
+{
+	return  0;
+}
+
+/* configure/autoconfigure the port */
+static void lpuart_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE)
+		port->type = PORT_LPUART;
+}
+
+static int lpuart_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	int ret = 0;
+
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_LPUART)
+		ret = -EINVAL;
+	if (port->irq != ser->irq)
+		ret = -EINVAL;
+	if (ser->io_type != UPIO_MEM)
+		ret = -EINVAL;
+	if (port->uartclk / 16 != ser->baud_base)
+		ret = -EINVAL;
+	if (port->iobase != ser->port)
+		ret = -EINVAL;
+	if (ser->hub6 != 0)
+		ret = -EINVAL;
+	return ret;
+}
+
+static struct uart_ops lpuart_pops = {
+	.tx_empty	= lpuart_tx_empty,
+	.set_mctrl	= lpuart_set_mctrl,
+	.get_mctrl	= lpuart_get_mctrl,
+	.stop_tx	= lpuart_stop_tx,
+	.start_tx	= lpuart_start_tx,
+	.stop_rx	= lpuart_stop_rx,
+	.enable_ms	= lpuart_enable_ms,
+	.break_ctl	= lpuart_break_ctl,
+	.startup	= lpuart_startup,
+	.shutdown	= lpuart_shutdown,
+	.set_termios	= lpuart_set_termios,
+	.type		= lpuart_type,
+	.request_port	= lpuart_request_port,
+	.release_port	= lpuart_release_port,
+	.config_port	= lpuart_config_port,
+	.verify_port	= lpuart_verify_port,
+};
+
+static struct lpuart_port *lpuart_ports[UART_NR];
+
+#ifdef CONFIG_SERIAL_FSL_LPUART_CONSOLE
+static void lpuart_console_putchar(struct uart_port *port, int ch)
+{
+	while (!(readb(port->membase + UARTSR1) & UARTSR1_TDRE))
+		barrier();
+
+	writeb(ch, port->membase + UARTDR);
+}
+
+static void
+lpuart_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct lpuart_port *sport = lpuart_ports[co->index];
+	unsigned char  old_cr2, cr2;
+
+	/* first save CR2 and then disable interrupts */
+	cr2 = old_cr2 = readb(sport->port.membase + UARTCR2);
+	cr2 |= (UARTCR2_TE |  UARTCR2_RE);
+	cr2 &= ~(UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_RIE);
+	writeb(cr2, sport->port.membase + UARTCR2);
+
+	uart_console_write(&sport->port, s, count, lpuart_console_putchar);
+
+	/* wait for transmitter finish complete and restore CR2 */
+	while (!(readb(sport->port.membase + UARTSR1) & UARTSR1_TC))
+		barrier();
+
+	writeb(old_cr2, sport->port.membase + UARTCR2);
+}
+
+/*
+ * if the port was already initialised (eg, by a boot loader),
+ * try to determine the current setup.
+ */
+static void __init
+lpuart_console_get_options(struct lpuart_port *sport, int *baud,
+			   int *parity, int *bits)
+{
+	unsigned char cr, bdh, bdl, brfa;
+	unsigned int sbr, uartclk, baud_raw;
+
+	cr = readb(sport->port.membase + UARTCR2);
+	cr &= UARTCR2_TE | UARTCR2_RE;
+	if (!cr)
+		return;
+
+	/* ok, the port was enabled */
+
+	cr = readb(sport->port.membase + UARTCR1);
+
+	*parity = 'n';
+	if (cr & UARTCR1_PE) {
+		if (cr & UARTCR1_PT)
+			*parity = 'o';
+		else
+			*parity = 'e';
+	}
+
+	if (cr & UARTCR1_M)
+		*bits = 9;
+	else
+		*bits = 8;
+
+	bdh = readb(sport->port.membase + UARTBDH);
+	bdh &= UARTBDH_SBR_MASK;
+	bdl = readb(sport->port.membase + UARTBDL);
+	sbr = bdh;
+	sbr <<= 8;
+	sbr |= bdl;
+	brfa = readb(sport->port.membase + UARTCR4);
+	brfa &= UARTCR4_BRFA_MASK;
+
+	uartclk = clk_get_rate(sport->clk);
+	/*
+	 * baud = mod_clk/(16*(sbr[13]+(brfa)/32)
+	 */
+	baud_raw = uartclk / (16 * (sbr + brfa / 32));
+
+	if (*baud != baud_raw)
+		printk(KERN_INFO "Serial: Console lpuart rounded baud rate"
+				"from %d to %d\n", baud_raw, *baud);
+}
+
+static int __init lpuart_console_setup(struct console *co, char *options)
+{
+	struct lpuart_port *sport;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	/*
+	 * check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if (co->index == -1 || co->index >= ARRAY_SIZE(lpuart_ports))
+		co->index = 0;
+
+	sport = lpuart_ports[co->index];
+	if (sport == NULL)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	else
+		lpuart_console_get_options(sport, &baud, &parity, &bits);
+
+	lpuart_setup_watermark(sport);
+
+	return uart_set_options(&sport->port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver lpuart_reg;
+static struct console lpuart_console = {
+	.name		= DEV_NAME,
+	.write		= lpuart_console_write,
+	.device		= uart_console_device,
+	.setup		= lpuart_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &lpuart_reg,
+};
+
+#define LPUART_CONSOLE	(&lpuart_console)
+#else
+#define LPUART_CONSOLE	NULL
+#endif
+
+static struct uart_driver lpuart_reg = {
+	.owner		= THIS_MODULE,
+	.driver_name	= DRIVER_NAME,
+	.dev_name	= DEV_NAME,
+	.nr		= ARRAY_SIZE(lpuart_ports),
+	.cons		= LPUART_CONSOLE,
+};
+
+static int lpuart_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct lpuart_port *sport;
+	struct resource *res;
+	int ret;
+
+	sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
+	if (!sport)
+		return -ENOMEM;
+
+	pdev->dev.coherent_dma_mask = 0;
+
+	ret = of_alias_get_id(np, "serial");
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
+		return ret;
+	}
+	sport->port.line = ret;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+
+	sport->port.mapbase = res->start;
+	sport->port.membase = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(sport->port.membase))
+		return PTR_ERR(sport->port.membase);
+
+	sport->port.dev = &pdev->dev;
+	sport->port.type = PORT_LPUART;
+	sport->port.iotype = UPIO_MEM;
+	sport->port.irq = platform_get_irq(pdev, 0);
+	sport->port.ops = &lpuart_pops;
+	sport->port.flags = UPF_BOOT_AUTOCONF;
+
+	sport->clk = devm_clk_get(&pdev->dev, "ipg");
+	if (IS_ERR(sport->clk)) {
+		ret = PTR_ERR(sport->clk);
+		dev_err(&pdev->dev, "failed to get uart clk: %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(sport->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable uart clk: %d\n", ret);
+		return ret;
+	}
+
+	sport->port.uartclk = clk_get_rate(sport->clk);
+
+	lpuart_ports[sport->port.line] = sport;
+
+	platform_set_drvdata(pdev, &sport->port);
+
+	ret = uart_add_one_port(&lpuart_reg, &sport->port);
+	if (ret) {
+		clk_disable_unprepare(sport->clk);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int lpuart_remove(struct platform_device *pdev)
+{
+	struct lpuart_port *sport = platform_get_drvdata(pdev);
+
+	uart_remove_one_port(&lpuart_reg, &sport->port);
+
+	clk_disable_unprepare(sport->clk);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int lpuart_suspend(struct device *dev)
+{
+	struct lpuart_port *sport = dev_get_drvdata(dev);
+
+	uart_suspend_port(&lpuart_reg, &sport->port);
+
+	return 0;
+}
+
+static int lpuart_resume(struct device *dev)
+{
+	struct lpuart_port *sport = dev_get_drvdata(dev);
+
+	uart_resume_port(&lpuart_reg, &sport->port);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(lpuart_pm_ops, lpuart_suspend, lpuart_resume);
+
+static struct platform_driver lpuart_driver = {
+	.probe		= lpuart_probe,
+	.remove		= lpuart_remove,
+	.driver		= {
+		.name	= "fsl-lpuart",
+		.owner	= THIS_MODULE,
+		.of_match_table = lpuart_dt_ids,
+		.pm	= &lpuart_pm_ops,
+	},
+};
+
+static int __init lpuart_serial_init(void)
+{
+	int ret;
+
+	pr_info("serial: Freescale lpuart driver\n");
+
+	ret = uart_register_driver(&lpuart_reg);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&lpuart_driver);
+	if (ret)
+		uart_unregister_driver(&lpuart_reg);
+
+	return 0;
+}
+
+static void __exit lpuart_serial_exit(void)
+{
+	platform_driver_unregister(&lpuart_driver);
+	uart_unregister_driver(&lpuart_reg);
+}
+
+module_init(lpuart_serial_init);
+module_exit(lpuart_serial_exit);
+
+MODULE_DESCRIPTION("Freescale lpuart serial port driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
index 74c2bf7..c8eaeb5 100644
--- a/include/uapi/linux/serial_core.h
+++ b/include/uapi/linux/serial_core.h
@@ -226,4 +226,7 @@ 
 /* Rocketport EXPRESS/INFINITY */
 #define PORT_RP2	102
 
+/* Freescale lpuart */
+#define PORT_LPUART	103
+
 #endif /* _UAPILINUX_SERIAL_CORE_H */