From db310b43e5b444a4e2854f3d69d002c2f0d0605c Mon Sep 17 00:00:00 2001 From: Jae Hyun Yoo Date: Wed, 13 Mar 2019 15:53:24 -0700 Subject: [PATCH] misc: Add clock control logic into Aspeed LPC MBOX driver If LPC MBOX driver is registered ahead of lpc-ctrl module, LPC MBOX block will be enabled without heart beating of LCLK until lpc-ctrl enables the LCLK. This issue causes improper handling on host interrupts when the host sends interrupt in that time frame. Then kernel eventually forcibly disables the interrupt with dumping stack and printing a 'nobody cared this irq' message out. To prevent this issue, all LPC sub-nodes should enable LCLK individually so this patch adds clock control logic into the LPC MBOX driver. Signed-off-by: Jae Hyun Yoo --- arch/arm/boot/dts/aspeed-g4.dtsi | 1 + arch/arm/boot/dts/aspeed-g5.dtsi | 1 + drivers/misc/aspeed-lpc-mbox.c | 42 +++++++++++++++++++++++++++++++--------- 3 files changed, 35 insertions(+), 9 deletions(-) diff --git a/arch/arm/boot/dts/aspeed-g4.dtsi b/arch/arm/boot/dts/aspeed-g4.dtsi index a5072ed1f823..729245b74c13 100644 --- a/arch/arm/boot/dts/aspeed-g4.dtsi +++ b/arch/arm/boot/dts/aspeed-g4.dtsi @@ -389,6 +389,7 @@ reg = <0x180 0x5c>; interrupts = <46>; #mbox-cells = <1>; + clocks = <&syscon ASPEED_CLK_GATE_LCLK>; status = "disabled"; }; }; diff --git a/arch/arm/boot/dts/aspeed-g5.dtsi b/arch/arm/boot/dts/aspeed-g5.dtsi index 6a2f161e7548..df9d63a94264 100644 --- a/arch/arm/boot/dts/aspeed-g5.dtsi +++ b/arch/arm/boot/dts/aspeed-g5.dtsi @@ -493,6 +493,7 @@ reg = <0x180 0x5c>; interrupts = <46>; #mbox-cells = <1>; + clocks = <&syscon ASPEED_CLK_GATE_LCLK>; status = "disabled"; }; }; diff --git a/drivers/misc/aspeed-lpc-mbox.c b/drivers/misc/aspeed-lpc-mbox.c index 0933e0553953..f105d27786ac 100644 --- a/drivers/misc/aspeed-lpc-mbox.c +++ b/drivers/misc/aspeed-lpc-mbox.c @@ -7,6 +7,7 @@ * 2 of the License, or (at your option) any later version. */ +#include #include #include #include @@ -37,7 +38,9 @@ struct aspeed_mbox { struct miscdevice miscdev; struct regmap *regmap; + struct clk *clk; unsigned int base; + int irq; wait_queue_head_t queue; struct mutex mutex; }; @@ -237,16 +240,16 @@ static int aspeed_mbox_config_irq(struct aspeed_mbox *mbox, struct platform_device *pdev) { struct device *dev = &pdev->dev; - int rc, irq; + int rc; - irq = irq_of_parse_and_map(dev->of_node, 0); - if (!irq) + mbox->irq = platform_get_irq(pdev, 0); + if (!mbox->irq) return -ENODEV; - rc = devm_request_irq(dev, irq, aspeed_mbox_irq, - IRQF_SHARED, DEVICE_NAME, mbox); + rc = devm_request_irq(dev, mbox->irq, aspeed_mbox_irq, + IRQF_SHARED, DEVICE_NAME, mbox); if (rc < 0) { - dev_err(dev, "Unable to request IRQ %d\n", irq); + dev_err(dev, "Unable to request IRQ %d\n", mbox->irq); return rc; } @@ -301,6 +304,19 @@ static int aspeed_mbox_probe(struct platform_device *pdev) mutex_init(&mbox->mutex); init_waitqueue_head(&mbox->queue); + mbox->clk = devm_clk_get(dev, NULL); + if (IS_ERR(mbox->clk)) { + rc = PTR_ERR(mbox->clk); + if (rc != -EPROBE_DEFER) + dev_err(dev, "couldn't get clock\n"); + return rc; + } + rc = clk_prepare_enable(mbox->clk); + if (rc) { + dev_err(dev, "couldn't enable clock\n"); + return rc; + } + mbox->miscdev.minor = MISC_DYNAMIC_MINOR; mbox->miscdev.name = DEVICE_NAME; mbox->miscdev.fops = &aspeed_mbox_fops; @@ -308,17 +324,24 @@ static int aspeed_mbox_probe(struct platform_device *pdev) rc = misc_register(&mbox->miscdev); if (rc) { dev_err(dev, "Unable to register device\n"); - return rc; + goto err; } rc = aspeed_mbox_config_irq(mbox, pdev); if (rc) { dev_err(dev, "Failed to configure IRQ\n"); misc_deregister(&mbox->miscdev); - return rc; + goto err; } + dev_info(&pdev->dev, "LPC mbox registered, irq %d\n", mbox->irq); + return 0; + +err: + clk_disable_unprepare(mbox->clk); + + return rc; } static int aspeed_mbox_remove(struct platform_device *pdev) @@ -326,6 +349,7 @@ static int aspeed_mbox_remove(struct platform_device *pdev) struct aspeed_mbox *mbox = dev_get_drvdata(&pdev->dev); misc_deregister(&mbox->miscdev); + clk_disable_unprepare(mbox->clk); return 0; } @@ -335,6 +359,7 @@ static const struct of_device_id aspeed_mbox_match[] = { { .compatible = "aspeed,ast2500-mbox" }, { }, }; +MODULE_DEVICE_TABLE(of, aspeed_mbox_match); static struct platform_driver aspeed_mbox_driver = { .driver = { @@ -347,7 +372,6 @@ static struct platform_driver aspeed_mbox_driver = { module_platform_driver(aspeed_mbox_driver); -MODULE_DEVICE_TABLE(of, aspeed_mbox_match); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Cyril Bur "); MODULE_DESCRIPTION("Aspeed mailbox device driver"); -- 2.7.4