[PATCH] serial: 8250_of: Add basic PM runtime support

[PATCH] serial: 8250_of: Add basic PM runtime support

[Franklin S Cooper Jr]

Add basic PM Runtime support.

Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
---
 drivers/tty/serial/8250/8250_of.c | 35 ++++++++++++++++++++++++-----------
 1 file changed, 24 insertions(+), 11 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
index 6c5a8ca..94e7c93 100644
--- a/drivers/tty/serial/8250/8250_of.c
+++ b/drivers/tty/serial/8250/8250_of.c
@@ -18,6 +18,7 @@
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
+#include <linux/pm_runtime.h>
 #include <linux/clk.h>
 #include <linux/reset.h>
 
@@ -65,6 +66,10 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 	int ret;
 
 	memset(port, 0, sizeof *port);
+
+	pm_runtime_enable(&ofdev->dev);
+	pm_runtime_get_sync(&ofdev->dev);
+
 	if (of_property_read_u32(np, "clock-frequency", &clk)) {
 
 		/* Get clk rate through clk driver if present */
@@ -72,12 +77,13 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 		if (IS_ERR(info->clk)) {
 			dev_warn(&ofdev->dev,
 				"clk or clock-frequency not defined\n");
-			return PTR_ERR(info->clk);
+			ret = PTR_ERR(info->clk);
+			goto err_pmruntime;
 		}
 
 		ret = clk_prepare_enable(info->clk);
 		if (ret < 0)
-			return ret;
+			goto err_pmruntime;
 
 		clk = clk_get_rate(info->clk);
 	}
@@ -170,8 +176,10 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 err_dispose:
 	irq_dispose_mapping(port->irq);
 err_unprepare:
-	if (info->clk)
-		clk_disable_unprepare(info->clk);
+	clk_disable_unprepare(info->clk);
+err_pmruntime:
+	pm_runtime_put_sync(&ofdev->dev);
+	pm_runtime_disable(&ofdev->dev);
 	return ret;
 }
 
@@ -227,8 +235,9 @@ static int of_platform_serial_probe(struct platform_device *ofdev)
 	return 0;
 err_dispose:
 	irq_dispose_mapping(port8250.port.irq);
-	if (info->clk)
-		clk_disable_unprepare(info->clk);
+	pm_runtime_put_sync(&ofdev->dev);
+	pm_runtime_disable(&ofdev->dev);
+	clk_disable_unprepare(info->clk);
 err_free:
 	kfree(info);
 	return ret;
@@ -244,8 +253,9 @@ static int of_platform_serial_remove(struct platform_device *ofdev)
 	serial8250_unregister_port(info->line);
 
 	reset_control_assert(info->rst);
-	if (info->clk)
-		clk_disable_unprepare(info->clk);
+	pm_runtime_put_sync(&ofdev->dev);
+	pm_runtime_disable(&ofdev->dev);
+	clk_disable_unprepare(info->clk);
 	kfree(info);
 	return 0;
 }
@@ -259,9 +269,10 @@ static int of_serial_suspend(struct device *dev)
 
 	serial8250_suspend_port(info->line);
 
-	if (info->clk && (!uart_console(port) || console_suspend_enabled))
+	if ((!uart_console(port) || console_suspend_enabled)) {
+		pm_runtime_put_sync(&ofdev->dev);
 		clk_disable_unprepare(info->clk);
-
+	}
 	return 0;
 }
 
@@ -271,8 +282,10 @@ static int of_serial_resume(struct device *dev)
 	struct uart_8250_port *port8250 = serial8250_get_port(info->line);
 	struct uart_port *port = &port8250->port;
 
-	if (info->clk && (!uart_console(port) || console_suspend_enabled))
+	if ((!uart_console(port) || console_suspend_enabled)) {
+		pm_runtime_get_sync(&ofdev->dev);
 		clk_prepare_enable(info->clk);
+	}
 
 	serial8250_resume_port(info->line);
 
-- 
2.9.4.dirty

Re: [PATCH] serial: 8250_of: Add basic PM runtime support

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 2217 bytes --]

Hi Franklin,

[auto build test ERROR on tty/tty-testing]
[also build test ERROR on next-20170802]
[cannot apply to v4.13-rc3]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Franklin-S-Cooper-Jr/serial-8250_of-Add-basic-PM-runtime-support/20170803-151414
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-testing
config: sparc64-allmodconfig (attached as .config)
compiler: sparc64-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
        wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=sparc64 

All errors (new ones prefixed by >>):

   drivers/tty//serial/8250/8250_of.c: In function 'of_serial_suspend':
>> drivers/tty//serial/8250/8250_of.c:273:24: error: 'ofdev' undeclared (first use in this function)
      pm_runtime_put_sync(&ofdev->dev);
                           ^~~~~
   drivers/tty//serial/8250/8250_of.c:273:24: note: each undeclared identifier is reported only once for each function it appears in
   drivers/tty//serial/8250/8250_of.c: In function 'of_serial_resume':
   drivers/tty//serial/8250/8250_of.c:286:24: error: 'ofdev' undeclared (first use in this function)
      pm_runtime_get_sync(&ofdev->dev);
                           ^~~~~

vim +/ofdev +273 drivers/tty//serial/8250/8250_of.c

   262	
   263	#ifdef CONFIG_PM_SLEEP
   264	static int of_serial_suspend(struct device *dev)
   265	{
   266		struct of_serial_info *info = dev_get_drvdata(dev);
   267		struct uart_8250_port *port8250 = serial8250_get_port(info->line);
   268		struct uart_port *port = &port8250->port;
   269	
   270		serial8250_suspend_port(info->line);
   271	
   272		if ((!uart_console(port) || console_suspend_enabled)) {
 > 273			pm_runtime_put_sync(&ofdev->dev);
   274			clk_disable_unprepare(info->clk);
   275		}
   276		return 0;
   277	}
   278	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 51285 bytes --]

Re: [PATCH] serial: 8250_of: Add basic PM runtime support

[Greg KH]

On Wed, Aug 02, 2017 at 11:32:18AM -0500, Franklin S Cooper Jr wrote:
> Add basic PM Runtime support.
> 

Why?  How?  For what?

Come on, we need better changelogs than just 5 words...