can: xilinx: Convert to runtime_pm

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: Kedareswara rao Appana <appanad@xilinx.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 101 insertions, 75 deletions

diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
index fc55e8e0351d..ad3806542d33 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;
@@ -843,6 +844,13 @@ 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) {
@@ -850,29 +858,17 @@ 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) {
@@ -888,13 +884,11 @@ 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;
 }
 
@@ -911,12 +905,11 @@ 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;
 }
@@ -935,27 +928,20 @@ 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;
 }
 
 
@@ -968,15 +954,45 @@ 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)) {
@@ -987,43 +1003,55 @@ static int __maybe_unused xcan_suspend(struct device *dev)
         priv->write_reg(priv, XCAN_MSR_OFFSET, XCAN_MSR_SLEEP_MASK);
         priv->can.state = CAN_STATE_SLEEPING;
 
-        clk_disable(priv->bus_clk);
-        clk_disable(priv->can_clk);
+        clk_disable_unprepare(priv->bus_clk);
+        clk_disable_unprepare(priv->can_clk);
 
         return 0;
 }
 
 /**
- * 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);
+        ret = clk_prepare_enable(priv->bus_clk);
         if (ret) {
                 dev_err(dev, "Cannot enable clock.\n");
                 return ret;
         }
-        ret = clk_enable(priv->can_clk);
+        ret = clk_prepare_enable(priv->can_clk);
         if (ret) {
                 dev_err(dev, "Cannot enable clock.\n");
                 clk_disable_unprepare(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;
+        priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK);
+        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);
         }
@@ -1031,7 +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_RUNTIME_PM_OPS(xcan_runtime_suspend, xcan_runtime_resume, NULL)
+};
 
 /**
  * xcan_probe - Platform registration call
@@ -1072,7 +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;
@@ -1114,21 +1145,17 @@ static int xcan_probe(struct platform_device *pdev)
                 }
         }
 
-        ret = clk_prepare_enable(priv->can_clk);
-        if (ret) {
-                dev_err(&pdev->dev, "unable to enable device clock\n");
-                goto err_free;
-        }
-
-        ret = clk_prepare_enable(priv->bus_clk);
-        if (ret) {
-                dev_err(&pdev->dev, "unable to enable bus clock\n");
-                goto err_unprepare_disable_dev;
-        }
-
         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;
+        }
+
         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;
@@ -1141,22 +1168,23 @@ static int xcan_probe(struct platform_device *pdev)
         ret = register_candev(ndev);
         if (ret) {
                 dev_err(&pdev->dev, "fail to register failed (err=%d)\n", ret);
-                goto err_unprepare_disable_busclk;
+                goto err_disableclks;
         }
 
         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_unprepare_disable_busclk:
-        clk_disable_unprepare(priv->bus_clk);
-err_unprepare_disable_dev:
-        clk_disable_unprepare(priv->can_clk);
+err_disableclks:
+        pm_runtime_put(priv->dev);
+err_pmdisable:
+        pm_runtime_disable(&pdev->dev);
 err_free:
         free_candev(ndev);
 err:
@@ -1175,10 +1203,8 @@ static int xcan_remove(struct platform_device *pdev)
         struct net_device *ndev = platform_get_drvdata(pdev);
         struct xcan_priv *priv = netdev_priv(ndev);
 
-        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);
         free_candev(ndev);