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

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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@xxxxxx>

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
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