can: m_can: allow keeping the transceiver running in suspend

Add a flag to the device class structure that leaves the chip in a
running state with rx interrupt enabled, so that an m_can device driver
can configure and use the interrupt as a wakeup source.

Signed-off-by: Martin Hundebøll <martin@geanix.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 290880ce5329c1434c9025e1099dac5d5d5f6561..14b231c4d7ecf1667118013bc31512bdd16bb4b2 100644 (file)
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -2382,7 +2382,15 @@ int m_can_class_suspend(struct device *dev)
        if (netif_running(ndev)) {
                netif_stop_queue(ndev);
                netif_device_detach(ndev);
-               m_can_stop(ndev);
+
+               /* leave the chip running with rx interrupt enabled if it is
+                * used as a wake-up source.
+                */
+               if (cdev->pm_wake_source)
+                       m_can_write(cdev, M_CAN_IE, IR_RF0N);
+               else
+                       m_can_stop(ndev);
+
                m_can_clk_stop(cdev);
        }
 
@@ -2409,11 +2417,15 @@ int m_can_class_resume(struct device *dev)
                ret = m_can_clk_start(cdev);
                if (ret)
                        return ret;
-               ret  = m_can_start(ndev);
-               if (ret) {
-                       m_can_clk_stop(cdev);
 
-                       return ret;
+               if (cdev->pm_wake_source) {
+                       m_can_write(cdev, M_CAN_IE, cdev->active_interrupts);
+               } else {
+                       ret  = m_can_start(ndev);
+                       if (ret) {
+                               m_can_clk_stop(cdev);
+                               return ret;
+                       }
                }
 
                netif_device_attach(ndev);

diff --git a/drivers/net/can/m_can/m_can.h b/drivers/net/can/m_can/m_can.h
index 2986c4ce0b2f327c5fd8a0b0fd2d2a261b156898..3a9edc29259385c9d6c20c27d2e450f40cb134e7 100644 (file)
--- a/drivers/net/can/m_can/m_can.h
+++ b/drivers/net/can/m_can/m_can.h
@@ -97,6 +97,7 @@ struct m_can_classdev {
        u32 irqstatus;
 
        int pm_clock_support;
+       int pm_wake_source;
        int is_peripheral;
 
        // Cached M_CAN_IE register content

diff --git a/drivers/net/can/m_can/m_can_pci.c b/drivers/net/can/m_can/m_can_pci.c
index f2219aa2824b3c581280fde6cf6decf003e50c06..45400de4163d93d30e147ca04b8f47ac299ec58c 100644 (file)
--- a/drivers/net/can/m_can/m_can_pci.c
+++ b/drivers/net/can/m_can/m_can_pci.c
@@ -125,6 +125,7 @@ static int m_can_pci_probe(struct pci_dev *pci, const struct pci_device_id *id)
        mcan_class->dev = &pci->dev;
        mcan_class->net->irq = pci_irq_vector(pci, 0);
        mcan_class->pm_clock_support = 1;
+       mcan_class->pm_wake_source = 0;
        mcan_class->can.clock.freq = id->driver_data;
        mcan_class->ops = &m_can_pci_ops;
 

diff --git a/drivers/net/can/m_can/m_can_platform.c b/drivers/net/can/m_can/m_can_platform.c
index ab1b8211a61cf544c3060479dbc4df5a2ac550e8..df0367124b4c536d392a8d6d033d0d96d73c8ab2 100644 (file)
--- a/drivers/net/can/m_can/m_can_platform.c
+++ b/drivers/net/can/m_can/m_can_platform.c
@@ -139,6 +139,7 @@ static int m_can_plat_probe(struct platform_device *pdev)
 
        mcan_class->net->irq = irq;
        mcan_class->pm_clock_support = 1;
+       mcan_class->pm_wake_source = 0;
        mcan_class->can.clock.freq = clk_get_rate(mcan_class->cclk);
        mcan_class->dev = &pdev->dev;
        mcan_class->transceiver = transceiver;

diff --git a/drivers/net/can/m_can/tcan4x5x-core.c b/drivers/net/can/m_can/tcan4x5x-core.c
index ae8c42f5debd4dee37d60ee8224a2ce4572e76b4..71a9e1bec008cfaf9b6f5b5bfc0aad93350ae580 100644 (file)
--- a/drivers/net/can/m_can/tcan4x5x-core.c
+++ b/drivers/net/can/m_can/tcan4x5x-core.c
@@ -411,6 +411,7 @@ static int tcan4x5x_can_probe(struct spi_device *spi)
        priv->spi = spi;
 
        mcan_class->pm_clock_support = 0;
+       mcan_class->pm_wake_source = 0;
        mcan_class->can.clock.freq = freq;
        mcan_class->dev = &spi->dev;
        mcan_class->ops = &tcan4x5x_ops;