Re: [RESEND PATCH 1/2] of serial port driver - add clk_get_rate() support

Re: [RESEND PATCH 1/2] of serial port driver - add clk_get_rate() support

[Murali Karicheri]

On 10/16/2012 11:24 AM, Murali Karicheri wrote:
> Currently this driver expects the clock-frequency attribute. This
> patch allows getting clock-frequency through clk driver API
> clk_get_rate() if clock-frequency attribute is not defined.
>
> So in the device bindings for serial device, one can add clocks
> phandle to refer to the clk device to get the rate.
>
> Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
>
> diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c
> index 34e7187..6f64f02 100644
> --- a/drivers/tty/serial/of_serial.c
> +++ b/drivers/tty/serial/of_serial.c
> @@ -21,8 +21,10 @@
>   #include <linux/of_serial.h>
>   #include <linux/of_platform.h>
>   #include <linux/nwpserial.h>
> +#include <linux/clk.h>
>   
>   struct of_serial_info {
> +	struct clk *clk;
>   	int type;
>   	int line;
>   };
> @@ -51,7 +53,8 @@ EXPORT_SYMBOL_GPL(tegra_serial_handle_break);
>    * Fill a struct uart_port for a given device node
>    */
>   static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
> -					int type, struct uart_port *port)
> +			int type, struct uart_port *port,
> +			struct of_serial_info *info)
>   {
>   	struct resource resource;
>   	struct device_node *np = ofdev->dev.of_node;
> @@ -60,8 +63,17 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
>   
>   	memset(port, 0, sizeof *port);
>   	if (of_property_read_u32(np, "clock-frequency", &clk)) {
> -		dev_warn(&ofdev->dev, "no clock-frequency property set\n");
> -		return -ENODEV;
> +
> +		/* Get clk rate through clk driver if present */
> +		info->clk = clk_get(&ofdev->dev, NULL);
> +		if (info->clk == NULL) {
> +			dev_warn(&ofdev->dev,
> +				"clk or clock-frequency not defined\n");
> +			return -ENODEV;
> +		}
> +
> +		clk_prepare_enable(info->clk);
> +		clk = clk_get_rate(info->clk);
>   	}
>   	/* If current-speed was set, then try not to change it. */
>   	if (of_property_read_u32(np, "current-speed", &spd) == 0)
> @@ -70,7 +82,7 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
>   	ret = of_address_to_resource(np, 0, &resource);
>   	if (ret) {
>   		dev_warn(&ofdev->dev, "invalid address\n");
> -		return ret;
> +		goto out;
>   	}
>   
>   	spin_lock_init(&port->lock);
> @@ -97,7 +109,8 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
>   		default:
>   			dev_warn(&ofdev->dev, "unsupported reg-io-width (%d)\n",
>   				 prop);
> -			return -EINVAL;
> +			ret = -EINVAL;
> +			goto out;
>   		}
>   	}
>   
> @@ -111,6 +124,10 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
>   		port->handle_break = tegra_serial_handle_break;
>   
>   	return 0;
> +out:
> +	if (info->clk)
> +		clk_disable_unprepare(info->clk);
> +	return ret;
>   }
>   
>   /*
> @@ -137,7 +154,7 @@ static int __devinit of_platform_serial_probe(struct platform_device *ofdev)
>   		return -ENOMEM;
>   
>   	port_type = (unsigned long)match->data;
> -	ret = of_platform_serial_setup(ofdev, port_type, &port);
> +	ret = of_platform_serial_setup(ofdev, port_type, &port, info);
>   	if (ret)
>   		goto out;
>   
> @@ -193,6 +210,9 @@ static int of_platform_serial_remove(struct platform_device *ofdev)
>   		/* need to add code for these */
>   		break;
>   	}
> +
> +	if (info->clk)
> +		clk_disable_unprepare(info->clk);
>   	kfree(info);
>   	return 0;
>   }
For some reason, I can't see the two patches in this series at the 
linux-serial server at http://marc.info/?l=linux-serial

Can someone tell me what could be wrong? My email seems to reach.. So trying
to reply and get this onto the mailing list.

Murali

Re: [RESEND PATCH 2/2] Documentation: of-serial.txt - update for clocks phandle for clk

[Murali Karicheri]

On 10/16/2012 11:24 AM, Murali Karicheri wrote:
> Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
>
> diff --git a/Documentation/devicetree/bindings/tty/serial/of-serial.txt b/Documentation/devicetree/bindings/tty/serial/of-serial.txt
> index 0847fde..423b7ff 100644
> --- a/Documentation/devicetree/bindings/tty/serial/of-serial.txt
> +++ b/Documentation/devicetree/bindings/tty/serial/of-serial.txt
> @@ -14,7 +14,10 @@ Required properties:
>   	- "serial" if the port type is unknown.
>   - reg : offset and length of the register set for the device.
>   - interrupts : should contain uart interrupt.
> -- clock-frequency : the input clock frequency for the UART.
> +- clock-frequency : the input clock frequency for the UART
> +	 or
> +  clocks phandle to refer to the clk used as per Documentation/devicetree
> +  /bindings/clock/clock-bindings.txt
>   
>   Optional properties:
>   - current-speed : the current active speed of the UART.

[RESEND PATCH 1/2] of serial port driver - add clk_get_rate() support

[Murali Karicheri]

Currently this driver expects the clock-frequency attribute. This
patch allows getting clock-frequency through clk driver API
clk_get_rate() if clock-frequency attribute is not defined.

So in the device bindings for serial device, one can add clocks
phandle to refer to the clk device to get the rate.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>

diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c
index 34e7187..6f64f02 100644
--- a/drivers/tty/serial/of_serial.c
+++ b/drivers/tty/serial/of_serial.c
@@ -21,8 +21,10 @@
 #include <linux/of_serial.h>
 #include <linux/of_platform.h>
 #include <linux/nwpserial.h>
+#include <linux/clk.h>
 
 struct of_serial_info {
+	struct clk *clk;
 	int type;
 	int line;
 };
@@ -51,7 +53,8 @@ EXPORT_SYMBOL_GPL(tegra_serial_handle_break);
  * Fill a struct uart_port for a given device node
  */
 static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
-					int type, struct uart_port *port)
+			int type, struct uart_port *port,
+			struct of_serial_info *info)
 {
 	struct resource resource;
 	struct device_node *np = ofdev->dev.of_node;
@@ -60,8 +63,17 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
 
 	memset(port, 0, sizeof *port);
 	if (of_property_read_u32(np, "clock-frequency", &clk)) {
-		dev_warn(&ofdev->dev, "no clock-frequency property set\n");
-		return -ENODEV;
+
+		/* Get clk rate through clk driver if present */
+		info->clk = clk_get(&ofdev->dev, NULL);
+		if (info->clk == NULL) {
+			dev_warn(&ofdev->dev,
+				"clk or clock-frequency not defined\n");
+			return -ENODEV;
+		}
+
+		clk_prepare_enable(info->clk);
+		clk = clk_get_rate(info->clk);
 	}
 	/* If current-speed was set, then try not to change it. */
 	if (of_property_read_u32(np, "current-speed", &spd) == 0)
@@ -70,7 +82,7 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
 	ret = of_address_to_resource(np, 0, &resource);
 	if (ret) {
 		dev_warn(&ofdev->dev, "invalid address\n");
-		return ret;
+		goto out;
 	}
 
 	spin_lock_init(&port->lock);
@@ -97,7 +109,8 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
 		default:
 			dev_warn(&ofdev->dev, "unsupported reg-io-width (%d)\n",
 				 prop);
-			return -EINVAL;
+			ret = -EINVAL;
+			goto out;
 		}
 	}
 
@@ -111,6 +124,10 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
 		port->handle_break = tegra_serial_handle_break;
 
 	return 0;
+out:
+	if (info->clk)
+		clk_disable_unprepare(info->clk);
+	return ret;
 }
 
 /*
@@ -137,7 +154,7 @@ static int __devinit of_platform_serial_probe(struct platform_device *ofdev)
 		return -ENOMEM;
 
 	port_type = (unsigned long)match->data;
-	ret = of_platform_serial_setup(ofdev, port_type, &port);
+	ret = of_platform_serial_setup(ofdev, port_type, &port, info);
 	if (ret)
 		goto out;
 
@@ -193,6 +210,9 @@ static int of_platform_serial_remove(struct platform_device *ofdev)
 		/* need to add code for these */
 		break;
 	}
+
+	if (info->clk)
+		clk_disable_unprepare(info->clk);
 	kfree(info);
 	return 0;
 }
-- 
1.7.9.5