[PATCH v2 0/5] tty/serial: atmel_serial: Device Tree support

[PATCH v2 0/5] tty/serial: atmel_serial: Device Tree support

[Nicolas Ferre]

Hi,

The goal of this patch series is to add device tree support to Atmel USART
driver: atmel_serial.
As this driver support RS485 mode, generic RS485 bindings have been added.

Some modifications are also included to ease the transition to parameter
settings comming from device tree.
The enumeration of ports is enhanced to be able to deal with several types
of port numbering: platform data, device tree or automatic.

Nicolas Ferre (5):
      tty/serial: RS485 bindings for device tree
      tty/serial: atmel_serial: change platform_data variable name
      tty/serial: atmel_serial: whitespace and braces modifications
      tty/serial: atmel_serial: auto-enumerate ports
      tty/serial: atmel_serial: add device tree support

 Documentation/devicetree/bindings/serial/rs485.txt |   31 +++++
 .../devicetree/bindings/tty/serial/atmel-usart.txt |   27 +++++
 Documentation/serial/serial-rs485.txt              |    5 +
 drivers/tty/serial/atmel_serial.c                  |  122 +++++++++++++++++---
 4 files changed, 170 insertions(+), 15 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/serial/rs485.txt
 create mode 100644 Documentation/devicetree/bindings/tty/serial/atmel-usart.txt

[PATCH v2 1/5] tty/serial: RS485 bindings for device tree

[Nicolas Ferre]

Generic bindings for RS485 feature included in some UARTs.
Those bindings have to be used withing an UART device tree node.
Documentation updated to link to the bindings definition.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
---
 Documentation/devicetree/bindings/serial/rs485.txt |   31 ++++++++++++++++++++
 .../devicetree/bindings/tty/serial/atmel-usart.txt |   27 +++++++++++++++++
 Documentation/serial/serial-rs485.txt              |    5 +++
 3 files changed, 63 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/serial/rs485.txt
 create mode 100644 Documentation/devicetree/bindings/tty/serial/atmel-usart.txt

diff --git a/Documentation/devicetree/bindings/serial/rs485.txt b/Documentation/devicetree/bindings/serial/rs485.txt
new file mode 100644
index 0000000..1e753c6
--- /dev/null
+++ b/Documentation/devicetree/bindings/serial/rs485.txt
@@ -0,0 +1,31 @@
+* RS485 serial communications
+
+The RTS signal is capable of automatically controlling line direction for
+the built-in half-duplex mode.
+The properties described hereafter shall be given to a half-duplex capable
+UART node.
+
+Required properties:
+- rs485-rts-delay: prop-encoded-array <a b> where:
+  * a is the delay beteween rts signal and beginning of data sent in milliseconds.
+      it corresponds to the delay before sending data.
+  * b is the delay between end of data sent and rts signal in milliseconds
+      it corresponds to the delay after sending data and actual release of the line.
+
+Optional properties:
+- linux,rs485-enabled-at-boot-time: empty property telling to enable the rs485
+  feature at boot time. It can be disabled later with proper ioctl.
+- rs485-rx-during-tx: empty property that enables the receiving of data even
+  whilst sending data.
+
+RS485 example for Atmel USART:
+	usart0: serial@fff8c000 {
+		compatible = "atmel,at91sam9260-usart";
+		reg = <0xfff8c000 0x4000>;
+		interrupts = <7>;
+		atmel,use-dma-rx;
+		atmel,use-dma-tx;
+		linux,rs485-enabled-at-boot-time;
+		rs485-rts-delay = <0 200>;		// in milliseconds
+	};
+
diff --git a/Documentation/devicetree/bindings/tty/serial/atmel-usart.txt b/Documentation/devicetree/bindings/tty/serial/atmel-usart.txt
new file mode 100644
index 0000000..a49d9a1
--- /dev/null
+++ b/Documentation/devicetree/bindings/tty/serial/atmel-usart.txt
@@ -0,0 +1,27 @@
+* Atmel Universal Synchronous Asynchronous Receiver/Transmitter (USART)
+
+Required properties:
+- compatible: Should be "atmel,<chip>-usart"
+  The compatible <chip> indicated will be the first SoC to support an
+  additional mode or an USART new feature.
+- reg: Should contain registers location and length
+- interrupts: Should contain interrupt
+
+Optional properties:
+- atmel,use-dma-rx: use of PDC or DMA for receiving data
+- atmel,use-dma-tx: use of PDC or DMA for transmitting data
+
+<chip> compatible description:
+- at91rm9200:  legacy USART support
+- at91sam9260: generic USART implementation for SAM9 SoCs
+
+Example:
+
+	usart0: serial@fff8c000 {
+		compatible = "atmel,at91sam9260-usart";
+		reg = <0xfff8c000 0x4000>;
+		interrupts = <7>;
+		atmel,use-dma-rx;
+		atmel,use-dma-tx;
+	};
+
diff --git a/Documentation/serial/serial-rs485.txt b/Documentation/serial/serial-rs485.txt
index c8878f8..079cb3d 100644
--- a/Documentation/serial/serial-rs485.txt
+++ b/Documentation/serial/serial-rs485.txt
@@ -28,6 +28,10 @@
    RS485 communications. This data structure is used to set and configure RS485
    parameters in the platform data and in ioctls.
 
+   The device tree can also provide RS485 boot time parameters (see [2]
+   for bindings). The driver is in charge of filling this data structure from
+   the values given by the device tree.
+
    Any driver for devices capable of working both as RS232 and RS485 should
    provide at least the following ioctls:
 
@@ -121,3 +125,4 @@
 5. REFERENCES
 
  [1]	include/linux/serial.h
+ [2]	Documentation/devicetree/bindings/serial/rs485.txt
-- 
1.7.5.4

[PATCH v2 3/5] tty/serial: atmel_serial: whitespace and braces modifications

[Nicolas Ferre]

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
---
 drivers/tty/serial/atmel_serial.c |    9 +++++----
 1 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index a507daa..bb72354 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -1433,10 +1433,10 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
 
 	memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));
 
-	if (pdata->regs)
+	if (pdata->regs) {
 		/* Already mapped by setup code */
 		port->membase = pdata->regs;
-	else {
+	} else {
 		port->flags	|= UPF_IOREMAP;
 		port->membase	= NULL;
 	}
@@ -1450,9 +1450,10 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
 		/* only enable clock when USART is in use */
 	}
 
-	atmel_port->use_dma_rx = pdata->use_dma_rx;
-	atmel_port->use_dma_tx = pdata->use_dma_tx;
+	atmel_port->use_dma_rx	= pdata->use_dma_rx;
+	atmel_port->use_dma_tx	= pdata->use_dma_tx;
 	atmel_port->rs485	= pdata->rs485;
+
 	/* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */
 	if (atmel_port->rs485.flags & SER_RS485_ENABLED)
 		atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
-- 
1.7.5.4

Re: [PATCH v2 3/5] tty/serial: atmel_serial: whitespace and braces modifications

[Grant Likely]

On Wed, Oct 12, 2011 at 06:06:58PM +0200, Nicolas Ferre wrote:
> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

Acked-by: Grant Likely <grant.likely@secretlab.ca>

> ---
>  drivers/tty/serial/atmel_serial.c |    9 +++++----
>  1 files changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index a507daa..bb72354 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -1433,10 +1433,10 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
>  
>  	memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));
>  
> -	if (pdata->regs)
> +	if (pdata->regs) {
>  		/* Already mapped by setup code */
>  		port->membase = pdata->regs;
> -	else {
> +	} else {
>  		port->flags	|= UPF_IOREMAP;
>  		port->membase	= NULL;
>  	}
> @@ -1450,9 +1450,10 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
>  		/* only enable clock when USART is in use */
>  	}
>  
> -	atmel_port->use_dma_rx = pdata->use_dma_rx;
> -	atmel_port->use_dma_tx = pdata->use_dma_tx;
> +	atmel_port->use_dma_rx	= pdata->use_dma_rx;
> +	atmel_port->use_dma_tx	= pdata->use_dma_tx;
>  	atmel_port->rs485	= pdata->rs485;
> +
>  	/* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */
>  	if (atmel_port->rs485.flags & SER_RS485_ENABLED)
>  		atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
> -- 
> 1.7.5.4
> 

[PATCH v2 2/5] tty/serial: atmel_serial: change platform_data variable name

[Nicolas Ferre]

Easier to follow if platform_data name is pdata.

Signed-off-by: Nicolas Ferre <nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
---
 drivers/tty/serial/atmel_serial.c |   14 +++++++-------
 1 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index c7232a9..a507daa 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -1417,13 +1417,13 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
 				      struct platform_device *pdev)
 {
 	struct uart_port *port = &atmel_port->uart;
-	struct atmel_uart_data *data = pdev->dev.platform_data;
+	struct atmel_uart_data *pdata = pdev->dev.platform_data;
 
 	port->iotype		= UPIO_MEM;
 	port->flags		= UPF_BOOT_AUTOCONF;
 	port->ops		= &atmel_pops;
 	port->fifosize		= 1;
-	port->line		= data->num;
+	port->line		= pdata->num;
 	port->dev		= &pdev->dev;
 	port->mapbase	= pdev->resource[0].start;
 	port->irq	= pdev->resource[1].start;
@@ -1433,9 +1433,9 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
 
 	memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));
 
-	if (data->regs)
+	if (pdata->regs)
 		/* Already mapped by setup code */
-		port->membase = data->regs;
+		port->membase = pdata->regs;
 	else {
 		port->flags	|= UPF_IOREMAP;
 		port->membase	= NULL;
@@ -1450,9 +1450,9 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
 		/* only enable clock when USART is in use */
 	}
 
-	atmel_port->use_dma_rx = data->use_dma_rx;
-	atmel_port->use_dma_tx = data->use_dma_tx;
-	atmel_port->rs485	= data->rs485;
+	atmel_port->use_dma_rx = pdata->use_dma_rx;
+	atmel_port->use_dma_tx = pdata->use_dma_tx;
+	atmel_port->rs485	= pdata->rs485;
 	/* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */
 	if (atmel_port->rs485.flags & SER_RS485_ENABLED)
 		atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
-- 
1.7.5.4

Re: [PATCH v2 2/5] tty/serial: atmel_serial: change platform_data variable name

[Grant Likely]

On Wed, Oct 12, 2011 at 06:06:57PM +0200, Nicolas Ferre wrote:
> Easier to follow if platform_data name is pdata.
> 
> Signed-off-by: Nicolas Ferre <nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>

Acked-by: Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>

> ---
>  drivers/tty/serial/atmel_serial.c |   14 +++++++-------
>  1 files changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index c7232a9..a507daa 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -1417,13 +1417,13 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
>  				      struct platform_device *pdev)
>  {
>  	struct uart_port *port = &atmel_port->uart;
> -	struct atmel_uart_data *data = pdev->dev.platform_data;
> +	struct atmel_uart_data *pdata = pdev->dev.platform_data;
>  
>  	port->iotype		= UPIO_MEM;
>  	port->flags		= UPF_BOOT_AUTOCONF;
>  	port->ops		= &atmel_pops;
>  	port->fifosize		= 1;
> -	port->line		= data->num;
> +	port->line		= pdata->num;
>  	port->dev		= &pdev->dev;
>  	port->mapbase	= pdev->resource[0].start;
>  	port->irq	= pdev->resource[1].start;
> @@ -1433,9 +1433,9 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
>  
>  	memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));
>  
> -	if (data->regs)
> +	if (pdata->regs)
>  		/* Already mapped by setup code */
> -		port->membase = data->regs;
> +		port->membase = pdata->regs;
>  	else {
>  		port->flags	|= UPF_IOREMAP;
>  		port->membase	= NULL;
> @@ -1450,9 +1450,9 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
>  		/* only enable clock when USART is in use */
>  	}
>  
> -	atmel_port->use_dma_rx = data->use_dma_rx;
> -	atmel_port->use_dma_tx = data->use_dma_tx;
> -	atmel_port->rs485	= data->rs485;
> +	atmel_port->use_dma_rx = pdata->use_dma_rx;
> +	atmel_port->use_dma_tx = pdata->use_dma_tx;
> +	atmel_port->rs485	= pdata->rs485;
>  	/* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */
>  	if (atmel_port->rs485.flags & SER_RS485_ENABLED)
>  		atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
> -- 
> 1.7.5.4
> 

[PATCH v2 4/5] tty/serial: atmel_serial: auto-enumerate ports

[Nicolas Ferre]

If no platform data provided to enumerate ports, use a bit field
to choose port number and check if port is already initialized.
Use this mechanism for both console and plain serial ports.

Signed-off-by: Nicolas Ferre <nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
---
 drivers/tty/serial/atmel_serial.c |   44 ++++++++++++++++++++++++++++++------
 1 files changed, 36 insertions(+), 8 deletions(-)

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index bb72354..1074329 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -157,6 +157,7 @@ struct atmel_uart_port {
 };
 
 static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
+static unsigned long atmel_ports_in_use;
 
 #ifdef SUPPORT_SYSRQ
 static struct console atmel_console;
@@ -1423,7 +1424,6 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
 	port->flags		= UPF_BOOT_AUTOCONF;
 	port->ops		= &atmel_pops;
 	port->fifosize		= 1;
-	port->line		= pdata->num;
 	port->dev		= &pdev->dev;
 	port->mapbase	= pdev->resource[0].start;
 	port->irq	= pdev->resource[1].start;
@@ -1613,10 +1613,15 @@ static struct console atmel_console = {
 static int __init atmel_console_init(void)
 {
 	if (atmel_default_console_device) {
-		add_preferred_console(ATMEL_DEVICENAME,
-				      atmel_default_console_device->id, NULL);
-		atmel_init_port(&atmel_ports[atmel_default_console_device->id],
-				atmel_default_console_device);
+		int id = atmel_default_console_device->id;
+		struct atmel_uart_port *port = &atmel_ports[id];
+
+		set_bit(id, &atmel_ports_in_use);
+		port->backup_imr = 0;
+		port->uart.line = id;
+
+		add_preferred_console(ATMEL_DEVICENAME, id, NULL);
+		atmel_init_port(port, atmel_default_console_device);
 		register_console(&atmel_console);
 	}
 
@@ -1715,12 +1720,33 @@ static int __devinit atmel_serial_probe(struct platform_device *pdev)
 	struct atmel_uart_port *port;
 	struct atmel_uart_data *pdata = pdev->dev.platform_data;
 	void *data;
-	int ret;
+	int ret = -ENODEV;
 
 	BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE & (ATMEL_SERIAL_RINGSIZE - 1));
 
-	port = &atmel_ports[pdata->num];
+	if (pdata)
+		ret = pdata->num;
+
+	if (ret < 0)
+		/* port id not found in platform data:
+		 * auto-enumerate it */
+		ret = find_first_zero_bit(&atmel_ports_in_use,
+				sizeof(atmel_ports_in_use));
+
+	if (ret > ATMEL_MAX_UART) {
+		ret = -ENODEV;
+		goto err;
+	}
+
+	if (test_and_set_bit(ret, &atmel_ports_in_use)) {
+		/* port already in use */
+		ret = -EBUSY;
+		goto err;
+	}
+
+	port = &atmel_ports[ret];
 	port->backup_imr = 0;
+	port->uart.line = ret;
 
 	atmel_init_port(port, pdev);
 
@@ -1766,7 +1792,7 @@ err_alloc_ring:
 		clk_put(port->clk);
 		port->clk = NULL;
 	}
-
+err:
 	return ret;
 }
 
@@ -1786,6 +1812,8 @@ static int __devexit atmel_serial_remove(struct platform_device *pdev)
 
 	/* "port" is allocated statically, so we shouldn't free it */
 
+	clear_bit(port->line, &atmel_ports_in_use);
+
 	clk_put(atmel_port->clk);
 
 	return ret;
-- 
1.7.5.4

Re: [PATCH v2 4/5] tty/serial: atmel_serial: auto-enumerate ports

[Grant Likely]

On Wed, Oct 12, 2011 at 06:06:59PM +0200, Nicolas Ferre wrote:
> If no platform data provided to enumerate ports, use a bit field
> to choose port number and check if port is already initialized.
> Use this mechanism for both console and plain serial ports.
> 
> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

Acked-by: Grant Likely <grant.likely@secretlab.ca>

> ---
>  drivers/tty/serial/atmel_serial.c |   44 ++++++++++++++++++++++++++++++------
>  1 files changed, 36 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index bb72354..1074329 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -157,6 +157,7 @@ struct atmel_uart_port {
>  };
>  
>  static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
> +static unsigned long atmel_ports_in_use;
>  
>  #ifdef SUPPORT_SYSRQ
>  static struct console atmel_console;
> @@ -1423,7 +1424,6 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
>  	port->flags		= UPF_BOOT_AUTOCONF;
>  	port->ops		= &atmel_pops;
>  	port->fifosize		= 1;
> -	port->line		= pdata->num;
>  	port->dev		= &pdev->dev;
>  	port->mapbase	= pdev->resource[0].start;
>  	port->irq	= pdev->resource[1].start;
> @@ -1613,10 +1613,15 @@ static struct console atmel_console = {
>  static int __init atmel_console_init(void)
>  {
>  	if (atmel_default_console_device) {
> -		add_preferred_console(ATMEL_DEVICENAME,
> -				      atmel_default_console_device->id, NULL);
> -		atmel_init_port(&atmel_ports[atmel_default_console_device->id],
> -				atmel_default_console_device);
> +		int id = atmel_default_console_device->id;
> +		struct atmel_uart_port *port = &atmel_ports[id];
> +
> +		set_bit(id, &atmel_ports_in_use);
> +		port->backup_imr = 0;
> +		port->uart.line = id;
> +
> +		add_preferred_console(ATMEL_DEVICENAME, id, NULL);
> +		atmel_init_port(port, atmel_default_console_device);
>  		register_console(&atmel_console);
>  	}
>  
> @@ -1715,12 +1720,33 @@ static int __devinit atmel_serial_probe(struct platform_device *pdev)
>  	struct atmel_uart_port *port;
>  	struct atmel_uart_data *pdata = pdev->dev.platform_data;
>  	void *data;
> -	int ret;
> +	int ret = -ENODEV;
>  
>  	BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE & (ATMEL_SERIAL_RINGSIZE - 1));
>  
> -	port = &atmel_ports[pdata->num];
> +	if (pdata)
> +		ret = pdata->num;
> +
> +	if (ret < 0)
> +		/* port id not found in platform data:
> +		 * auto-enumerate it */
> +		ret = find_first_zero_bit(&atmel_ports_in_use,
> +				sizeof(atmel_ports_in_use));
> +
> +	if (ret > ATMEL_MAX_UART) {
> +		ret = -ENODEV;
> +		goto err;
> +	}
> +
> +	if (test_and_set_bit(ret, &atmel_ports_in_use)) {
> +		/* port already in use */
> +		ret = -EBUSY;
> +		goto err;
> +	}
> +
> +	port = &atmel_ports[ret];
>  	port->backup_imr = 0;
> +	port->uart.line = ret;
>  
>  	atmel_init_port(port, pdev);
>  
> @@ -1766,7 +1792,7 @@ err_alloc_ring:
>  		clk_put(port->clk);
>  		port->clk = NULL;
>  	}
> -
> +err:
>  	return ret;
>  }
>  
> @@ -1786,6 +1812,8 @@ static int __devexit atmel_serial_remove(struct platform_device *pdev)
>  
>  	/* "port" is allocated statically, so we shouldn't free it */
>  
> +	clear_bit(port->line, &atmel_ports_in_use);
> +
>  	clk_put(atmel_port->clk);
>  
>  	return ret;
> -- 
> 1.7.5.4
> 

[PATCH v2 5/5] tty/serial: atmel_serial: add device tree support

[Nicolas Ferre]

Will use aliases to enumerate ports, if available.

Signed-off-by: Nicolas Ferre <nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
---
 drivers/tty/serial/atmel_serial.c |   79 +++++++++++++++++++++++++++++++++----
 1 files changed, 71 insertions(+), 8 deletions(-)

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 1074329..fc4081e 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -33,6 +33,8 @@
 #include <linux/sysrq.h>
 #include <linux/tty_flip.h>
 #include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/dma-mapping.h>
 #include <linux/atmel_pdc.h>
 #include <linux/atmel_serial.h>
@@ -163,6 +165,16 @@ static unsigned long atmel_ports_in_use;
 static struct console atmel_console;
 #endif
 
+#if defined(CONFIG_OF)
+static const struct of_device_id atmel_serial_dt_ids[] = {
+	{ .compatible = "atmel,at91rm9200-usart" },
+	{ .compatible = "atmel,at91sam9260-usart" },
+	{ /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, atmel_serial_dt_ids);
+#endif
+
 static inline struct atmel_uart_port *
 to_atmel_uart_port(struct uart_port *uart)
 {
@@ -1411,6 +1423,48 @@ static struct uart_ops atmel_pops = {
 #endif
 };
 
+static void __devinit atmel_of_init_port(struct atmel_uart_port *atmel_port,
+					 struct device_node *np)
+{
+	u32 rs485_delay[2];
+
+	/* DMA/PDC usage specification */
+	if (of_get_property(np, "atmel,use-dma-rx", NULL))
+		atmel_port->use_dma_rx	= 1;
+	else
+		atmel_port->use_dma_rx	= 0;
+	if (of_get_property(np, "atmel,use-dma-tx", NULL))
+		atmel_port->use_dma_tx	= 1;
+	else
+		atmel_port->use_dma_tx	= 0;
+
+	/* rs485 properties */
+	if (of_property_read_u32_array(np, "rs485-rts-delay",
+					    rs485_delay, 2) == 0) {
+		struct serial_rs485 *rs485conf = &atmel_port->rs485;
+
+		rs485conf->delay_rts_before_send = rs485_delay[0];
+		rs485conf->delay_rts_after_send = rs485_delay[1];
+		rs485conf->flags = 0;
+
+		if (rs485conf->delay_rts_before_send == 0 &&
+		    rs485conf->delay_rts_after_send == 0) {
+			rs485conf->flags |= SER_RS485_RTS_ON_SEND;
+		} else {
+			if (rs485conf->delay_rts_before_send)
+				rs485conf->flags |= SER_RS485_RTS_BEFORE_SEND;
+			if (rs485conf->delay_rts_after_send)
+				rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
+		}
+
+		if (of_get_property(np, "rs485-rx-during-tx", NULL))
+			rs485conf->flags |= SER_RS485_RX_DURING_TX;
+
+		if (of_get_property(np, "linux,rs485-enabled-at-boot-time", NULL))
+			rs485conf->flags |= SER_RS485_ENABLED;
+	}
+}
+
 /*
  * Configure the port from the platform device resource info.
  */
@@ -1420,6 +1474,14 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
 	struct uart_port *port = &atmel_port->uart;
 	struct atmel_uart_data *pdata = pdev->dev.platform_data;
 
+	if (pdev->dev.of_node) {
+		atmel_of_init_port(atmel_port, pdev->dev.of_node);
+	} else {
+		atmel_port->use_dma_rx	= pdata->use_dma_rx;
+		atmel_port->use_dma_tx	= pdata->use_dma_tx;
+		atmel_port->rs485	= pdata->rs485;
+	}
+
 	port->iotype		= UPIO_MEM;
 	port->flags		= UPF_BOOT_AUTOCONF;
 	port->ops		= &atmel_pops;
@@ -1433,7 +1495,7 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
 
 	memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));
 
-	if (pdata->regs) {
+	if (pdata && pdata->regs) {
 		/* Already mapped by setup code */
 		port->membase = pdata->regs;
 	} else {
@@ -1450,10 +1512,6 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
 		/* only enable clock when USART is in use */
 	}
 
-	atmel_port->use_dma_rx	= pdata->use_dma_rx;
-	atmel_port->use_dma_tx	= pdata->use_dma_tx;
-	atmel_port->rs485	= pdata->rs485;
-
 	/* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */
 	if (atmel_port->rs485.flags & SER_RS485_ENABLED)
 		atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
@@ -1718,17 +1776,21 @@ static int atmel_serial_resume(struct platform_device *pdev)
 static int __devinit atmel_serial_probe(struct platform_device *pdev)
 {
 	struct atmel_uart_port *port;
+	struct device_node *np = pdev->dev.of_node;
 	struct atmel_uart_data *pdata = pdev->dev.platform_data;
 	void *data;
 	int ret = -ENODEV;
 
 	BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE & (ATMEL_SERIAL_RINGSIZE - 1));
 
-	if (pdata)
-		ret = pdata->num;
+	if (np)
+		ret = of_alias_get_id(np, "serial");
+	else
+		if (pdata)
+			ret = pdata->num;
 
 	if (ret < 0)
-		/* port id not found in platform data:
+		/* port id not found in platform data nor device-tree aliases:
 		 * auto-enumerate it */
 		ret = find_first_zero_bit(&atmel_ports_in_use,
 				sizeof(atmel_ports_in_use));
@@ -1827,6 +1889,7 @@ static struct platform_driver atmel_serial_driver = {
 	.driver		= {
 		.name	= "atmel_usart",
 		.owner	= THIS_MODULE,
+		.of_match_table	= of_match_ptr(atmel_serial_dt_ids),
 	},
 };
 
-- 
1.7.5.4

Re: [PATCH v2 5/5] tty/serial: atmel_serial: add device tree support

[Grant Likely]

On Wed, Oct 12, 2011 at 06:07:00PM +0200, Nicolas Ferre wrote:
> Will use aliases to enumerate ports, if available.
> 
> Signed-off-by: Nicolas Ferre <nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>

Acked-by: Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>

> ---
>  drivers/tty/serial/atmel_serial.c |   79 +++++++++++++++++++++++++++++++++----
>  1 files changed, 71 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index 1074329..fc4081e 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -33,6 +33,8 @@
>  #include <linux/sysrq.h>
>  #include <linux/tty_flip.h>
>  #include <linux/platform_device.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
>  #include <linux/dma-mapping.h>
>  #include <linux/atmel_pdc.h>
>  #include <linux/atmel_serial.h>
> @@ -163,6 +165,16 @@ static unsigned long atmel_ports_in_use;
>  static struct console atmel_console;
>  #endif
>  
> +#if defined(CONFIG_OF)
> +static const struct of_device_id atmel_serial_dt_ids[] = {
> +	{ .compatible = "atmel,at91rm9200-usart" },
> +	{ .compatible = "atmel,at91sam9260-usart" },
> +	{ /* sentinel */ }
> +};
> +
> +MODULE_DEVICE_TABLE(of, atmel_serial_dt_ids);
> +#endif
> +
>  static inline struct atmel_uart_port *
>  to_atmel_uart_port(struct uart_port *uart)
>  {
> @@ -1411,6 +1423,48 @@ static struct uart_ops atmel_pops = {
>  #endif
>  };
>  
> +static void __devinit atmel_of_init_port(struct atmel_uart_port *atmel_port,
> +					 struct device_node *np)
> +{
> +	u32 rs485_delay[2];
> +
> +	/* DMA/PDC usage specification */
> +	if (of_get_property(np, "atmel,use-dma-rx", NULL))
> +		atmel_port->use_dma_rx	= 1;
> +	else
> +		atmel_port->use_dma_rx	= 0;
> +	if (of_get_property(np, "atmel,use-dma-tx", NULL))
> +		atmel_port->use_dma_tx	= 1;
> +	else
> +		atmel_port->use_dma_tx	= 0;
> +
> +	/* rs485 properties */
> +	if (of_property_read_u32_array(np, "rs485-rts-delay",
> +					    rs485_delay, 2) == 0) {
> +		struct serial_rs485 *rs485conf = &atmel_port->rs485;
> +
> +		rs485conf->delay_rts_before_send = rs485_delay[0];
> +		rs485conf->delay_rts_after_send = rs485_delay[1];
> +		rs485conf->flags = 0;
> +
> +		if (rs485conf->delay_rts_before_send == 0 &&
> +		    rs485conf->delay_rts_after_send == 0) {
> +			rs485conf->flags |= SER_RS485_RTS_ON_SEND;
> +		} else {
> +			if (rs485conf->delay_rts_before_send)
> +				rs485conf->flags |= SER_RS485_RTS_BEFORE_SEND;
> +			if (rs485conf->delay_rts_after_send)
> +				rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
> +		}
> +
> +		if (of_get_property(np, "rs485-rx-during-tx", NULL))
> +			rs485conf->flags |= SER_RS485_RX_DURING_TX;
> +
> +		if (of_get_property(np, "linux,rs485-enabled-at-boot-time", NULL))
> +			rs485conf->flags |= SER_RS485_ENABLED;
> +	}
> +}
> +
>  /*
>   * Configure the port from the platform device resource info.
>   */
> @@ -1420,6 +1474,14 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
>  	struct uart_port *port = &atmel_port->uart;
>  	struct atmel_uart_data *pdata = pdev->dev.platform_data;
>  
> +	if (pdev->dev.of_node) {
> +		atmel_of_init_port(atmel_port, pdev->dev.of_node);
> +	} else {
> +		atmel_port->use_dma_rx	= pdata->use_dma_rx;
> +		atmel_port->use_dma_tx	= pdata->use_dma_tx;
> +		atmel_port->rs485	= pdata->rs485;
> +	}
> +
>  	port->iotype		= UPIO_MEM;
>  	port->flags		= UPF_BOOT_AUTOCONF;
>  	port->ops		= &atmel_pops;
> @@ -1433,7 +1495,7 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
>  
>  	memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));
>  
> -	if (pdata->regs) {
> +	if (pdata && pdata->regs) {
>  		/* Already mapped by setup code */
>  		port->membase = pdata->regs;
>  	} else {
> @@ -1450,10 +1512,6 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
>  		/* only enable clock when USART is in use */
>  	}
>  
> -	atmel_port->use_dma_rx	= pdata->use_dma_rx;
> -	atmel_port->use_dma_tx	= pdata->use_dma_tx;
> -	atmel_port->rs485	= pdata->rs485;
> -
>  	/* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */
>  	if (atmel_port->rs485.flags & SER_RS485_ENABLED)
>  		atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
> @@ -1718,17 +1776,21 @@ static int atmel_serial_resume(struct platform_device *pdev)
>  static int __devinit atmel_serial_probe(struct platform_device *pdev)
>  {
>  	struct atmel_uart_port *port;
> +	struct device_node *np = pdev->dev.of_node;
>  	struct atmel_uart_data *pdata = pdev->dev.platform_data;
>  	void *data;
>  	int ret = -ENODEV;
>  
>  	BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE & (ATMEL_SERIAL_RINGSIZE - 1));
>  
> -	if (pdata)
> -		ret = pdata->num;
> +	if (np)
> +		ret = of_alias_get_id(np, "serial");
> +	else
> +		if (pdata)
> +			ret = pdata->num;
>  
>  	if (ret < 0)
> -		/* port id not found in platform data:
> +		/* port id not found in platform data nor device-tree aliases:
>  		 * auto-enumerate it */
>  		ret = find_first_zero_bit(&atmel_ports_in_use,
>  				sizeof(atmel_ports_in_use));
> @@ -1827,6 +1889,7 @@ static struct platform_driver atmel_serial_driver = {
>  	.driver		= {
>  		.name	= "atmel_usart",
>  		.owner	= THIS_MODULE,
> +		.of_match_table	= of_match_ptr(atmel_serial_dt_ids),
>  	},
>  };
>  
> -- 
> 1.7.5.4
> 

Re: [PATCH v2 1/5] tty/serial: RS485 bindings for device tree

[Grant Likely]

On Wed, Oct 12, 2011 at 06:06:56PM +0200, Nicolas Ferre wrote:
> Generic bindings for RS485 feature included in some UARTs.
> Those bindings have to be used withing an UART device tree node.
> Documentation updated to link to the bindings definition.
> 
> Signed-off-by: Nicolas Ferre <nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>

Acked-by: Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>

> ---
>  Documentation/devicetree/bindings/serial/rs485.txt |   31 ++++++++++++++++++++
>  .../devicetree/bindings/tty/serial/atmel-usart.txt |   27 +++++++++++++++++
>  Documentation/serial/serial-rs485.txt              |    5 +++
>  3 files changed, 63 insertions(+), 0 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/serial/rs485.txt
>  create mode 100644 Documentation/devicetree/bindings/tty/serial/atmel-usart.txt
> 
> diff --git a/Documentation/devicetree/bindings/serial/rs485.txt b/Documentation/devicetree/bindings/serial/rs485.txt
> new file mode 100644
> index 0000000..1e753c6
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/serial/rs485.txt
> @@ -0,0 +1,31 @@
> +* RS485 serial communications
> +
> +The RTS signal is capable of automatically controlling line direction for
> +the built-in half-duplex mode.
> +The properties described hereafter shall be given to a half-duplex capable
> +UART node.
> +
> +Required properties:
> +- rs485-rts-delay: prop-encoded-array <a b> where:
> +  * a is the delay beteween rts signal and beginning of data sent in milliseconds.
> +      it corresponds to the delay before sending data.
> +  * b is the delay between end of data sent and rts signal in milliseconds
> +      it corresponds to the delay after sending data and actual release of the line.
> +
> +Optional properties:
> +- linux,rs485-enabled-at-boot-time: empty property telling to enable the rs485
> +  feature at boot time. It can be disabled later with proper ioctl.
> +- rs485-rx-during-tx: empty property that enables the receiving of data even
> +  whilst sending data.
> +
> +RS485 example for Atmel USART:
> +	usart0: serial@fff8c000 {
> +		compatible = "atmel,at91sam9260-usart";
> +		reg = <0xfff8c000 0x4000>;
> +		interrupts = <7>;
> +		atmel,use-dma-rx;
> +		atmel,use-dma-tx;
> +		linux,rs485-enabled-at-boot-time;
> +		rs485-rts-delay = <0 200>;		// in milliseconds
> +	};
> +
> diff --git a/Documentation/devicetree/bindings/tty/serial/atmel-usart.txt b/Documentation/devicetree/bindings/tty/serial/atmel-usart.txt
> new file mode 100644
> index 0000000..a49d9a1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/tty/serial/atmel-usart.txt
> @@ -0,0 +1,27 @@
> +* Atmel Universal Synchronous Asynchronous Receiver/Transmitter (USART)
> +
> +Required properties:
> +- compatible: Should be "atmel,<chip>-usart"
> +  The compatible <chip> indicated will be the first SoC to support an
> +  additional mode or an USART new feature.
> +- reg: Should contain registers location and length
> +- interrupts: Should contain interrupt
> +
> +Optional properties:
> +- atmel,use-dma-rx: use of PDC or DMA for receiving data
> +- atmel,use-dma-tx: use of PDC or DMA for transmitting data
> +
> +<chip> compatible description:
> +- at91rm9200:  legacy USART support
> +- at91sam9260: generic USART implementation for SAM9 SoCs
> +
> +Example:
> +
> +	usart0: serial@fff8c000 {
> +		compatible = "atmel,at91sam9260-usart";
> +		reg = <0xfff8c000 0x4000>;
> +		interrupts = <7>;
> +		atmel,use-dma-rx;
> +		atmel,use-dma-tx;
> +	};
> +
> diff --git a/Documentation/serial/serial-rs485.txt b/Documentation/serial/serial-rs485.txt
> index c8878f8..079cb3d 100644
> --- a/Documentation/serial/serial-rs485.txt
> +++ b/Documentation/serial/serial-rs485.txt
> @@ -28,6 +28,10 @@
>     RS485 communications. This data structure is used to set and configure RS485
>     parameters in the platform data and in ioctls.
>  
> +   The device tree can also provide RS485 boot time parameters (see [2]
> +   for bindings). The driver is in charge of filling this data structure from
> +   the values given by the device tree.
> +
>     Any driver for devices capable of working both as RS232 and RS485 should
>     provide at least the following ioctls:
>  
> @@ -121,3 +125,4 @@
>  5. REFERENCES
>  
>   [1]	include/linux/serial.h
> + [2]	Documentation/devicetree/bindings/serial/rs485.txt
> -- 
> 1.7.5.4
>