Hi,

On Monday 15 January 2018 07:25 PM, Marc Kleine-Budde wrote:

On 01/10/2018 11:55 AM, Faiz Abbas wrote:

quoted

From: Franklin S Cooper Jr <redacted>

Add support for CONFIG_PM which is the new way to handle managing clocks.

Move the clock management to pm_runtime_resume() and pm_runtime_suspend()
callbacks for the driver.

CONFIG_PM is required by OMAP based devices to handle clock management.
Therefore, this allows future Texas Instruments SoCs that have the MCAN IP
to work with this driver.

Reviewed-by: Suman Anna <redacted>
Signed-off-by: Franklin S Cooper Jr <redacted>
[nsekhar@ti.com: handle pm_runtime_get_sync() failure, fix some bugs]
Signed-off-by: Sekhar Nori <redacted>
Signed-off-by: Faiz Abbas <redacted>
---
 drivers/net/can/m_can/m_can.c | 95 ++++++++++++++++++++++++++++---------------
 1 file changed, 62 insertions(+), 33 deletions(-)

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 07ebe7f..f5c5028 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c

@@ -23,6 +23,7 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/iopoll.h>
 #include <linux/can/dev.h>
 

@@ -625,21 +626,16 @@ static int m_can_clk_start(struct m_can_priv *priv)
 {
 	int err;
 
-	err = clk_prepare_enable(priv->hclk);
-	if (err)
-		return err;
-
-	err = clk_prepare_enable(priv->cclk);
+	err = pm_runtime_get_sync(priv->device);
 	if (err)
-		clk_disable_unprepare(priv->hclk);
+		pm_runtime_put_noidle(priv->device);
 
 	return err;
 }
 
 static void m_can_clk_stop(struct m_can_priv *priv)
 {
-	clk_disable_unprepare(priv->cclk);
-	clk_disable_unprepare(priv->hclk);
+	pm_runtime_put_sync(priv->device);
 }
 
 static int m_can_get_berr_counter(const struct net_device *dev,

@@ -1561,37 +1557,26 @@ static int m_can_plat_probe(struct platform_device *pdev)
 		goto failed_ret;
 	}
 
-	/* Enable clocks. Necessary to read Core Release in order to determine
-	 * M_CAN version
-	 */
-	ret = clk_prepare_enable(hclk);
-	if (ret)
-		goto disable_hclk_ret;
-
-	ret = clk_prepare_enable(cclk);
-	if (ret)
-		goto disable_cclk_ret;
-
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "m_can");
 	addr = devm_ioremap_resource(&pdev->dev, res);
 	irq = platform_get_irq_byname(pdev, "int0");
 
 	if (IS_ERR(addr) || irq < 0) {
 		ret = -EINVAL;
-		goto disable_cclk_ret;
+		goto failed_ret;
 	}
 
 	/* message ram could be shared */
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram");
 	if (!res) {
 		ret = -ENODEV;
-		goto disable_cclk_ret;
+		goto failed_ret;
 	}
 
 	mram_addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
 	if (!mram_addr) {
 		ret = -ENOMEM;
-		goto disable_cclk_ret;
+		goto failed_ret;
 	}
 
 	/* get message ram configuration */

@@ -1600,7 +1585,7 @@ static int m_can_plat_probe(struct platform_device *pdev)
 					 sizeof(mram_config_vals) / 4);
 	if (ret) {
 		dev_err(&pdev->dev, "Could not get Message RAM configuration.");
-		goto disable_cclk_ret;
+		goto failed_ret;
 	}
 
 	/* Get TX FIFO size

@@ -1612,13 +1597,9 @@ static int m_can_plat_probe(struct platform_device *pdev)
 	dev = alloc_candev(sizeof(*priv), tx_fifo_size);
 	if (!dev) {
 		ret = -ENOMEM;
-		goto disable_cclk_ret;
+		goto failed_ret;
 	}
 
-	ret = setup_m_can_dev(pdev, dev, addr);
-	if (ret)
-		goto disable_cclk_ret;
-
 	priv = netdev_priv(dev);
 	dev->irq = irq;
 	priv->device = &pdev->dev;

@@ -1632,6 +1613,20 @@ static int m_can_plat_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, dev);
 	SET_NETDEV_DEV(dev, &pdev->dev);
 
+	/* Enable clocks. Necessary to read Core Release in order to determine
+	 * M_CAN version
+	 */
+	pm_runtime_enable(&pdev->dev);
+	ret = pm_runtime_get_sync(&pdev->dev);

Why don't you make use of m_can_clk_start() here?

Sure. Will replace.

Thanks,
Faiz