Instead of enabling/disabling clocks at several locations in the driver,
Use the runtime_pm framework. This consolidates the actions for runtime PM
In the appropriate callbacks and makes the driver more readable and mantainable.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xxxxxxxxxx>
Signed-off-by: Kedareswara rao Appana <appanad@xxxxxxxxxx>
---
Changes for v5:
- Updated with the review comments.
Updated the remove fuction to use runtime_pm.
Chnages for v4:
- Updated with the review comments.
Changes for v3:
- Converted the driver to use runtime_pm.
Changes for v2:
- Removed the struct platform_device* from suspend/resume
as suggest by Lothar.
drivers/net/can/xilinx_can.c | 157 ++++++++++++++++++++++++++++-------------
1 files changed, 107 insertions(+), 50 deletions(-)
diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
index 6c67643..67aef00 100644
--- a/drivers/net/can/xilinx_can.c
+++ b/drivers/net/can/xilinx_can.c
@@ -32,6 +32,7 @@
#include <linux/can/dev.h>
#include <linux/can/error.h>
#include <linux/can/led.h>
+#include <linux/pm_runtime.h>
#define DRIVER_NAME "xilinx_can"
@@ -138,7 +139,7 @@ struct xcan_priv {
u32 (*read_reg)(const struct xcan_priv *priv, enum xcan_reg reg);
void (*write_reg)(const struct xcan_priv *priv, enum xcan_reg reg,
u32 val);
- struct net_device *dev;
+ struct device *dev;
void __iomem *reg_base;
unsigned long irq_flags;
struct clk *bus_clk;
@@ -842,6 +843,13 @@ static int xcan_open(struct net_device *ndev)
struct xcan_priv *priv = netdev_priv(ndev);
int ret;
+ ret = pm_runtime_get_sync(priv->dev);
+ if (ret < 0) {
+ netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
+ __func__, ret);
+ return ret;
+ }
+
ret = request_irq(ndev->irq, xcan_interrupt, priv->irq_flags,
ndev->name, ndev);
if (ret < 0) {
@@ -849,29 +857,17 @@ static int xcan_open(struct net_device *ndev)
goto err;
}
- ret = clk_prepare_enable(priv->can_clk);
- if (ret) {
- netdev_err(ndev, "unable to enable device clock\n");
- goto err_irq;
- }
-
- ret = clk_prepare_enable(priv->bus_clk);
- if (ret) {
- netdev_err(ndev, "unable to enable bus clock\n");
- goto err_can_clk;
- }
-
/* Set chip into reset mode */
ret = set_reset_mode(ndev);
if (ret < 0) {
netdev_err(ndev, "mode resetting failed!\n");
- goto err_bus_clk;
+ goto err_irq;
}
/* Common open */
ret = open_candev(ndev);
if (ret)
- goto err_bus_clk;
+ goto err_irq;
ret = xcan_chip_start(ndev);
if (ret < 0) {
@@ -887,13 +883,11 @@ static int xcan_open(struct net_device *ndev)
err_candev:
close_candev(ndev);
-err_bus_clk:
- clk_disable_unprepare(priv->bus_clk);
-err_can_clk:
- clk_disable_unprepare(priv->can_clk);
err_irq:
free_irq(ndev->irq, ndev);
err:
+ pm_runtime_put(priv->dev);
+
return ret;
}
@@ -910,12 +904,11 @@ static int xcan_close(struct net_device *ndev)
netif_stop_queue(ndev);
napi_disable(&priv->napi);
xcan_chip_stop(ndev);
- clk_disable_unprepare(priv->bus_clk);
- clk_disable_unprepare(priv->can_clk);
free_irq(ndev->irq, ndev);
close_candev(ndev);
can_led_event(ndev, CAN_LED_EVENT_STOP);
+ pm_runtime_put(priv->dev);
return 0;
}
@@ -934,27 +927,20 @@ static int xcan_get_berr_counter(const struct net_device *ndev,
struct xcan_priv *priv = netdev_priv(ndev);
int ret;
- ret = clk_prepare_enable(priv->can_clk);
- if (ret)
- goto err;
-
- ret = clk_prepare_enable(priv->bus_clk);
- if (ret)
- goto err_clk;
+ ret = pm_runtime_get_sync(priv->dev);
+ if (ret < 0) {
+ netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
+ __func__, ret);
+ return ret;
+ }
bec->txerr = priv->read_reg(priv, XCAN_ECR_OFFSET) & XCAN_ECR_TEC_MASK;
bec->rxerr = ((priv->read_reg(priv, XCAN_ECR_OFFSET) &
XCAN_ECR_REC_MASK) >> XCAN_ESR_REC_SHIFT);
- clk_disable_unprepare(priv->bus_clk);
- clk_disable_unprepare(priv->can_clk);
+ pm_runtime_put(priv->dev);
return 0;
-
-err_clk:
- clk_disable_unprepare(priv->can_clk);
-err:
- return ret;
}
@@ -967,15 +953,45 @@ static const struct net_device_ops xcan_netdev_ops = {
/**
* xcan_suspend - Suspend method for the driver
- * @dev: Address of the platform_device structure
+ * @dev: Address of the device structure
*
* Put the driver into low power mode.
- * Return: 0 always
+ * Return: 0 on success and failure value on error
*/
static int __maybe_unused xcan_suspend(struct device *dev)
{
- struct platform_device *pdev = dev_get_drvdata(dev);
- struct net_device *ndev = platform_get_drvdata(pdev);
+ if (!device_may_wakeup(dev))
+ return pm_runtime_force_suspend(dev);
+
+ return 0;
+}
+
+/**
+ * xcan_resume - Resume from suspend
+ * @dev: Address of the device structure
+ *
+ * Resume operation after suspend.
+ * Return: 0 on success and failure value on error
+ */
+static int __maybe_unused xcan_resume(struct device *dev)
+{
+ if (!device_may_wakeup(dev))
+ return pm_runtime_force_resume(dev);
+
+ return 0;
+
+}
+
+/**
+ * xcan_runtime_suspend - Runtime suspend method for the driver
+ * @dev: Address of the device structure
+ *
+ * Put the driver into low power mode.
+ * Return: 0 always
+ */
+static int __maybe_unused xcan_runtime_suspend(struct device *dev)
+{
+ struct net_device *ndev = dev_get_drvdata(dev);
struct xcan_priv *priv = netdev_priv(ndev);
if (netif_running(ndev)) {
@@ -993,18 +1009,18 @@ static int __maybe_unused xcan_suspend(struct device *dev)
}
/**
- * xcan_resume - Resume from suspend
- * @dev: Address of the platformdevice structure
+ * xcan_runtime_resume - Runtime resume from suspend
+ * @dev: Address of the device structure
*
* Resume operation after suspend.
* Return: 0 on success and failure value on error
*/
-static int __maybe_unused xcan_resume(struct device *dev)
+static int __maybe_unused xcan_runtime_resume(struct device *dev)
{
- struct platform_device *pdev = dev_get_drvdata(dev);
- struct net_device *ndev = platform_get_drvdata(pdev);
+ struct net_device *ndev = dev_get_drvdata(dev);
struct xcan_priv *priv = netdev_priv(ndev);
int ret;
+ u32 isr, status;
ret = clk_enable(priv->bus_clk);
if (ret) {
@@ -1014,15 +1030,28 @@ static int __maybe_unused xcan_resume(struct device *dev)
ret = clk_enable(priv->can_clk);
if (ret) {
dev_err(dev, "Cannot enable clock.\n");
- clk_disable_unprepare(priv->bus_clk);
+ clk_disable(priv->bus_clk);
return ret;
}
priv->write_reg(priv, XCAN_MSR_OFFSET, 0);
priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_CEN_MASK);
- priv->can.state = CAN_STATE_ERROR_ACTIVE;
+ isr = priv->read_reg(priv, XCAN_ISR_OFFSET);
+ status = priv->read_reg(priv, XCAN_SR_OFFSET);
if (netif_running(ndev)) {
+ if (isr & XCAN_IXR_BSOFF_MASK) {
+ priv->can.state = CAN_STATE_BUS_OFF;
+ priv->write_reg(priv, XCAN_SRR_OFFSET,
+ XCAN_SRR_RESET_MASK);
+ } else if ((status & XCAN_SR_ESTAT_MASK) ==
+ XCAN_SR_ESTAT_MASK) {
+ priv->can.state = CAN_STATE_ERROR_PASSIVE;
+ } else if (status & XCAN_SR_ERRWRN_MASK) {
+ priv->can.state = CAN_STATE_ERROR_WARNING;
+ } else {
+ priv->can.state = CAN_STATE_ERROR_ACTIVE;
+ }
netif_device_attach(ndev);
netif_start_queue(ndev);
}
@@ -1030,7 +1059,10 @@ static int __maybe_unused xcan_resume(struct device *dev)
return 0;
}
-static SIMPLE_DEV_PM_OPS(xcan_dev_pm_ops, xcan_suspend, xcan_resume);
+static const struct dev_pm_ops xcan_dev_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(xcan_suspend, xcan_resume)
+ SET_PM_RUNTIME_PM_OPS(xcan_runtime_suspend, xcan_runtime_resume, NULL)
+};
/**
* xcan_probe - Platform registration call
@@ -1071,7 +1103,7 @@ static int xcan_probe(struct platform_device *pdev)
return -ENOMEM;
priv = netdev_priv(ndev);
- priv->dev = ndev;
+ priv->dev = &pdev->dev;
priv->can.bittiming_const = &xcan_bittiming_const;
priv->can.do_set_mode = xcan_do_set_mode;
priv->can.do_get_berr_counter = xcan_get_berr_counter;
@@ -1137,6 +1169,16 @@ static int xcan_probe(struct platform_device *pdev)
netif_napi_add(ndev, &priv->napi, xcan_rx_poll, rx_max);
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_irq_safe(&pdev->dev);
+ 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 = register_candev(ndev);
if (ret) {
dev_err(&pdev->dev, "fail to register failed (err=%d)\n", ret);
@@ -1144,15 +1186,19 @@ static int xcan_probe(struct platform_device *pdev)
}
devm_can_led_init(ndev);
- clk_disable_unprepare(priv->bus_clk);
- clk_disable_unprepare(priv->can_clk);
+
+ pm_runtime_put(&pdev->dev);
+
netdev_dbg(ndev, "reg_base=0x%p irq=%d clock=%d, tx fifo depth:%d\n",
priv->reg_base, ndev->irq, priv->can.clock.freq,
priv->tx_max);
return 0;
+err_pmdisable:
+ pm_runtime_disable(&pdev->dev);
err_unprepare_disable_busclk:
+ pm_runtime_put(priv->dev);
clk_disable_unprepare(priv->bus_clk);
err_unprepare_disable_dev:
clk_disable_unprepare(priv->can_clk);
@@ -1173,12 +1219,23 @@ static int xcan_remove(struct platform_device *pdev)
{
struct net_device *ndev = platform_get_drvdata(pdev);
struct xcan_priv *priv = netdev_priv(ndev);
+ int ret;
+
+ ret = pm_runtime_get_sync(&pdev->dev);
+ if (ret < 0) {
+ netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
+ __func__, ret);
+ return ret;
+ }
if (set_reset_mode(ndev) < 0)
netdev_err(ndev, "mode resetting failed!\n");
unregister_candev(ndev);
+ pm_runtime_disable(&pdev->dev);
netif_napi_del(&priv->napi);
+ clk_disable_unprepare(priv->bus_clk);
+ clk_disable_unprepare(priv->can_clk);
free_candev(ndev);
return 0;
--
1.7.4
--
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