[PATCH] can: xilinx: Enable clocks even when CONFIG_PM is disabled

From: shubhrajyoti.datta
Date: Tue Sep 04 2018 - 08:28:21 EST


From: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>

Currently the clocks are enabled only in the runtime calls.
When CONFIG_PM is disabled the driver does not work as the
clocks are disabled.
Fix the same by enabling the clocks in probe.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
---
drivers/net/can/xilinx_can.c | 31 +++++++++++++++++++++++--------
1 file changed, 23 insertions(+), 8 deletions(-)

diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
index 131cce1..bf39b52 100644
--- a/drivers/net/can/xilinx_can.c
+++ b/drivers/net/can/xilinx_can.c
@@ -1550,14 +1550,21 @@ static int xcan_probe(struct platform_device *pdev)
priv->write_reg = xcan_write_reg_le;
priv->read_reg = xcan_read_reg_le;

- pm_runtime_enable(&pdev->dev);
- ret = pm_runtime_get_sync(&pdev->dev);
- if (ret < 0) {
- netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
- __func__, ret);
- goto err_pmdisable;
+ ret = clk_prepare_enable(priv->bus_clk);
+ if (ret) {
+ dev_err(&pdev->dev, "Cannot enable clock.\n");
+ goto err_free;
+ }
+
+ ret = clk_prepare_enable(priv->can_clk);
+ if (ret) {
+ dev_err(&pdev->dev, "Cannot enable clock.\n");
+ goto err_clk;
}

+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+
if (priv->read_reg(priv, XCAN_SR_OFFSET) != XCAN_SR_CONFIG_MASK) {
priv->write_reg = xcan_write_reg_be;
priv->read_reg = xcan_read_reg_be;
@@ -1584,9 +1591,11 @@ static int xcan_probe(struct platform_device *pdev)
return 0;

err_disableclks:
- pm_runtime_put(priv->dev);
-err_pmdisable:
pm_runtime_disable(&pdev->dev);
+ pm_runtime_set_suspended(&pdev->dev);
+ clk_disable_unprepare(priv->can_clk);
+err_clk:
+ clk_disable_unprepare(priv->bus_clk);
err_free:
free_candev(ndev);
err:
@@ -1606,6 +1615,12 @@ static int xcan_remove(struct platform_device *pdev)
struct xcan_priv *priv = netdev_priv(ndev);

unregister_candev(ndev);
+
+ if (!pm_runtime_suspended(&pdev->dev)) {
+ clk_disable_unprepare(priv->bus_clk);
+ clk_disable_unprepare(priv->can_clk);
+ }
+
pm_runtime_disable(&pdev->dev);
netif_napi_del(&priv->napi);
free_candev(ndev);
--
2.1.1