From bb410c03b999a361ab4e11e103d88707b4155bf9 Mon Sep 17 00:00:00 2001 From: Judith Mendez Date: Fri, 7 Jul 2023 15:47:13 -0500 Subject: [PATCH 1/2] dt-bindings: net: can: Remove interrupt properties for MCAN On AM62x SoC, MCANs on MCU domain do not have hardware interrupt routed to A53 Linux, instead they will use software interrupt by timer polling. To enable timer polling method, interrupts should be optional so remove interrupts property from required section and add an example for MCAN node with timer polling enabled. Reviewed-by: Tony Lindgren Reviewed-by: Conor Dooley Acked-by: Krzysztof Kozlowski Signed-off-by: Judith Mendez Link: https://lore.kernel.org/all/20230707204714.62964-2-jm@ti.com Signed-off-by: Marc Kleine-Budde --- .../bindings/net/can/bosch,m_can.yaml | 20 +++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/Documentation/devicetree/bindings/net/can/bosch,m_can.yaml b/Documentation/devicetree/bindings/net/can/bosch,m_can.yaml index 67879aab623b..bb518c831f7b 100644 --- a/Documentation/devicetree/bindings/net/can/bosch,m_can.yaml +++ b/Documentation/devicetree/bindings/net/can/bosch,m_can.yaml @@ -122,8 +122,6 @@ required: - compatible - reg - reg-names - - interrupts - - interrupt-names - clocks - clock-names - bosch,mram-cfg @@ -132,6 +130,7 @@ additionalProperties: false examples: - | + // Example with interrupts #include can@20e8000 { compatible = "bosch,m_can"; @@ -149,4 +148,21 @@ examples: }; }; + - | + // Example with timer polling + #include + can@20e8000 { + compatible = "bosch,m_can"; + reg = <0x020e8000 0x4000>, <0x02298000 0x4000>; + reg-names = "m_can", "message_ram"; + clocks = <&clks IMX6SX_CLK_CANFD>, + <&clks IMX6SX_CLK_CANFD>; + clock-names = "hclk", "cclk"; + bosch,mram-cfg = <0x0 0 0 32 0 0 0 1>; + + can-transceiver { + max-bitrate = <5000000>; + }; + }; + ... From b382380c0d2da427aaffca931e4a3b831048cace Mon Sep 17 00:00:00 2001 From: Judith Mendez Date: Fri, 7 Jul 2023 15:47:14 -0500 Subject: [PATCH 2/2] can: m_can: Add hrtimer to generate software interrupt Introduce timer polling method to MCAN since some SoCs may not have M_CAN interrupt routed to A53 Linux and do not have interrupt property in device tree M_CAN node. On AM62x SoC, MCANs on MCU domain do not have hardware interrupt routed to A53 Linux, instead they will use timer polling method. Add an hrtimer to MCAN class device. Each MCAN will have its own hrtimer instantiated if there is no hardware interrupt found in device tree M_CAN node. The timer will generate a software interrupt every 1 ms. In hrtimer callback, we check if there is a transaction pending by reading a register, then process by calling the isr if there is. Tested-by: Hiago De Franco # Toradex Verdin AM62 Reviewed-by: Tony Lindgren Signed-off-by: Judith Mendez Link: https://lore.kernel.org/all/20230707204714.62964-3-jm@ti.com Signed-off-by: Marc Kleine-Budde --- drivers/net/can/m_can/m_can.c | 32 +++++++++++++++++++++++++- drivers/net/can/m_can/m_can.h | 3 +++ drivers/net/can/m_can/m_can_platform.c | 21 +++++++++++++---- 3 files changed, 51 insertions(+), 5 deletions(-) diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index c5af92bcc9c9..13fd84b2e2dd 100644 --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include #include @@ -308,6 +309,9 @@ enum m_can_reg { #define TX_EVENT_MM_MASK GENMASK(31, 24) #define TX_EVENT_TXTS_MASK GENMASK(15, 0) +/* Hrtimer polling interval */ +#define HRTIMER_POLL_INTERVAL_MS 1 + /* The ID and DLC registers are adjacent in M_CAN FIFO memory, * and we can save a (potentially slow) bus round trip by combining * reads and writes to them. @@ -1414,6 +1418,12 @@ static int m_can_start(struct net_device *dev) m_can_enable_all_interrupts(cdev); + if (!dev->irq) { + dev_dbg(cdev->dev, "Start hrtimer\n"); + hrtimer_start(&cdev->hrtimer, ms_to_ktime(HRTIMER_POLL_INTERVAL_MS), + HRTIMER_MODE_REL_PINNED); + } + return 0; } @@ -1568,6 +1578,11 @@ static void m_can_stop(struct net_device *dev) { struct m_can_classdev *cdev = netdev_priv(dev); + if (!dev->irq) { + dev_dbg(cdev->dev, "Stop hrtimer\n"); + hrtimer_cancel(&cdev->hrtimer); + } + /* disable all interrupts */ m_can_disable_all_interrupts(cdev); @@ -1793,6 +1808,18 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb, return NETDEV_TX_OK; } +static enum hrtimer_restart hrtimer_callback(struct hrtimer *timer) +{ + struct m_can_classdev *cdev = container_of(timer, struct + m_can_classdev, hrtimer); + + m_can_isr(0, cdev->net); + + hrtimer_forward_now(timer, ms_to_ktime(HRTIMER_POLL_INTERVAL_MS)); + + return HRTIMER_RESTART; +} + static int m_can_open(struct net_device *dev) { struct m_can_classdev *cdev = netdev_priv(dev); @@ -1831,7 +1858,7 @@ static int m_can_open(struct net_device *dev) err = request_threaded_irq(dev->irq, NULL, m_can_isr, IRQF_ONESHOT, dev->name, dev); - } else { + } else if (dev->irq) { err = request_irq(dev->irq, m_can_isr, IRQF_SHARED, dev->name, dev); } @@ -2027,6 +2054,9 @@ int m_can_class_register(struct m_can_classdev *cdev) goto clk_disable; } + if (!cdev->net->irq) + cdev->hrtimer.function = &hrtimer_callback; + ret = m_can_dev_setup(cdev); if (ret) goto rx_offload_del; diff --git a/drivers/net/can/m_can/m_can.h b/drivers/net/can/m_can/m_can.h index a839dc71dc9b..2ac18ac867a4 100644 --- a/drivers/net/can/m_can/m_can.h +++ b/drivers/net/can/m_can/m_can.h @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -93,6 +94,8 @@ struct m_can_classdev { int is_peripheral; struct mram_cfg mcfg[MRAM_CFG_NUM]; + + struct hrtimer hrtimer; }; struct m_can_classdev *m_can_class_allocate_dev(struct device *dev, int sizeof_priv); diff --git a/drivers/net/can/m_can/m_can_platform.c b/drivers/net/can/m_can/m_can_platform.c index 94dc82644113..cdb28d6a092c 100644 --- a/drivers/net/can/m_can/m_can_platform.c +++ b/drivers/net/can/m_can/m_can_platform.c @@ -5,6 +5,7 @@ // // Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/ +#include #include #include @@ -82,7 +83,7 @@ static int m_can_plat_probe(struct platform_device *pdev) void __iomem *addr; void __iomem *mram_addr; struct phy *transceiver; - int irq, ret = 0; + int irq = 0, ret = 0; mcan_class = m_can_class_allocate_dev(&pdev->dev, sizeof(struct m_can_plat_priv)); @@ -96,12 +97,24 @@ static int m_can_plat_probe(struct platform_device *pdev) goto probe_fail; addr = devm_platform_ioremap_resource_byname(pdev, "m_can"); - irq = platform_get_irq_byname(pdev, "int0"); - if (IS_ERR(addr) || irq < 0) { - ret = -EINVAL; + if (IS_ERR(addr)) { + ret = PTR_ERR(addr); goto probe_fail; } + if (device_property_present(mcan_class->dev, "interrupts") || + device_property_present(mcan_class->dev, "interrupt-names")) { + irq = platform_get_irq_byname(pdev, "int0"); + if (irq < 0) { + ret = irq; + goto probe_fail; + } + } else { + dev_dbg(mcan_class->dev, "Polling enabled, initialize hrtimer"); + hrtimer_init(&mcan_class->hrtimer, CLOCK_MONOTONIC, + HRTIMER_MODE_REL_PINNED); + } + /* message ram could be shared */ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram"); if (!res) {