[PATCH v2 1/2] soc: aspeed: add BMC-side PCIe BMC device driver

Taken from ASPEED 6.18 Kernel SDK

Add support for VUART over PCIe between BMC and host.
This add BMC side driver.

Signed-off-by: Jacky Chou <[email protected]>
Signed-off-by: aspeedyh <[email protected]>
Signed-off-by: Grégoire Layet <[email protected]>
Tested-by: Grégoire Layet <[email protected]>
---
 drivers/soc/aspeed/Kconfig          |   7 ++
 drivers/soc/aspeed/Makefile         |   1 +
 drivers/soc/aspeed/aspeed-bmc-dev.c | 187 ++++++++++++++++++++++++++++
 3 files changed, 195 insertions(+)
 create mode 100644 drivers/soc/aspeed/aspeed-bmc-dev.c

diff --git a/drivers/soc/aspeed/Kconfig b/drivers/soc/aspeed/Kconfig
index f579ee0b5afa..3e1fcf3c3268 100644
--- a/drivers/soc/aspeed/Kconfig
+++ b/drivers/soc/aspeed/Kconfig
@@ -4,6 +4,13 @@ if ARCH_ASPEED || COMPILE_TEST
 
 menu "ASPEED SoC drivers"
 
+config ASPEED_BMC_DEV
+	tristate "ASPEED BMC Device"
+	default n
+	help
+	  Enable support for the ASPEED AST2600 BMC Device.
+	  This exposes the PCIe-to-LPC bridge of the BMC to the host over PCIe.
+
 config ASPEED_LPC_CTRL
 	tristate "ASPEED LPC firmware cycle control"
 	select REGMAP
diff --git a/drivers/soc/aspeed/Makefile b/drivers/soc/aspeed/Makefile
index b35d74592964..fab0d247df66 100644
--- a/drivers/soc/aspeed/Makefile
+++ b/drivers/soc/aspeed/Makefile
@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_ASPEED_BMC_DEV)		+= aspeed-bmc-dev.o
 obj-$(CONFIG_ASPEED_LPC_CTRL)		+= aspeed-lpc-ctrl.o
 obj-$(CONFIG_ASPEED_LPC_SNOOP)		+= aspeed-lpc-snoop.o
 obj-$(CONFIG_ASPEED_UART_ROUTING)	+= aspeed-uart-routing.o
diff --git a/drivers/soc/aspeed/aspeed-bmc-dev.c b/drivers/soc/aspeed/aspeed-bmc-dev.c
new file mode 100644
index 000000000000..7a204b543c97
--- /dev/null
+++ b/drivers/soc/aspeed/aspeed-bmc-dev.c
@@ -0,0 +1,187 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+// Copyright (C) ASPEED Technology Inc.
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+
+#include <linux/regmap.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/syscon.h>
+
+#define SCU_TRIGGER_MSI
+
+/* AST2600 SCU */
+#define ASPEED_SCU04			0x04
+#define AST2600A3_SCU04				0x05030303
+#define ASPEED_SCUC20			0xC20
+#define ASPEED_SCUC24			0xC24
+#define MSI_ROUTING_MASK			GENMASK(11, 10)
+#define PCIDEV1_INTX_MSI_HOST2BMC_EN		BIT(18)
+#define MSI_ROUTING_PCIe2LPC_PCIDEV0		(0x1 << 10)
+#define MSI_ROUTING_PCIe2LPC_PCIDEV1		(0x2 << 10)
+
+#define ASPEED_SCU_PCIE_CONF_CTRL	0xC20
+#define  SCU_PCIE_CONF_BMC_DEV_EN			 BIT(8)
+#define  SCU_PCIE_CONF_BMC_DEV_EN_MMIO		 BIT(9)
+#define  SCU_PCIE_CONF_BMC_DEV_EN_MSI		 BIT(11)
+#define  SCU_PCIE_CONF_BMC_DEV_EN_IRQ		 BIT(13)
+#define  SCU_PCIE_CONF_BMC_DEV_EN_DMA		 BIT(14)
+#define  SCU_PCIE_CONF_BMC_DEV_EN_E2L		 BIT(15)
+#define  SCU_PCIE_CONF_BMC_DEV_EN_LPC_DECODE BIT(21)
+
+#define ASPEED_SCU_BMC_DEV_CLASS	0xC68
+
+
+struct aspeed_platform {
+	int (*init)(struct platform_device *pdev);
+};
+
+struct aspeed_bmc_device {
+	struct device *dev;
+	int id;
+	void __iomem *reg_base;
+
+	int pcie2lpc;
+	int irq;
+
+	const struct aspeed_platform *platform;
+
+	struct regmap *scu;
+	int pcie_irq;
+};
+
+
+static int aspeed_ast2600_init(struct platform_device *pdev)
+{
+	struct aspeed_bmc_device *bmc_device = platform_get_drvdata(pdev);
+	struct device *dev = &pdev->dev;
+	u32 pcie_config_ctl = SCU_PCIE_CONF_BMC_DEV_EN_IRQ |
+			      SCU_PCIE_CONF_BMC_DEV_EN_MMIO | SCU_PCIE_CONF_BMC_DEV_EN;
+	u32 scu_id;
+
+	bmc_device->scu = syscon_regmap_lookup_by_phandle(dev->of_node, "aspeed,scu");
+	if (IS_ERR(bmc_device->scu)) {
+		dev_err(&pdev->dev, "failed to find SCU regmap\n");
+		return PTR_ERR(bmc_device->scu);
+	}
+
+	if (bmc_device->pcie2lpc)
+		pcie_config_ctl |= SCU_PCIE_CONF_BMC_DEV_EN_E2L |
+				   SCU_PCIE_CONF_BMC_DEV_EN_LPC_DECODE;
+
+	regmap_update_bits(bmc_device->scu, ASPEED_SCU_PCIE_CONF_CTRL,
+			   pcie_config_ctl, pcie_config_ctl);
+
+	/* update class code to others as it is a MFD device */
+	regmap_write(bmc_device->scu, ASPEED_SCU_BMC_DEV_CLASS, 0xff000000);
+
+#ifdef SCU_TRIGGER_MSI
+	//SCUC24[17]: Enable PCI device 1 INTx/MSI from SCU560[15]. Will be added in next version
+	regmap_update_bits(bmc_device->scu, ASPEED_SCUC20, BIT(11) | BIT(14), BIT(11) | BIT(14));
+
+	regmap_read(bmc_device->scu, ASPEED_SCU04, &scu_id);
+	if (scu_id == AST2600A3_SCU04)
+		regmap_update_bits(bmc_device->scu, ASPEED_SCUC24,
+				   PCIDEV1_INTX_MSI_HOST2BMC_EN | MSI_ROUTING_MASK,
+				   PCIDEV1_INTX_MSI_HOST2BMC_EN | MSI_ROUTING_PCIe2LPC_PCIDEV1);
+	else
+		regmap_update_bits(bmc_device->scu, ASPEED_SCUC24,
+				   BIT(17) | BIT(14) | BIT(11), BIT(17) | BIT(14) | BIT(11));
+#else
+	//SCUC24[18]: Enable PCI device 1 INTx/MSI from Host-to-BMC controller.
+	regmap_update_bits(bmc_device->scu, 0xc24, BIT(18) | BIT(14), BIT(18) | BIT(14));
+#endif
+
+
+	return 0;
+}
+
+
+static struct aspeed_platform ast2600_plaform = {
+	.init = aspeed_ast2600_init
+};
+
+
+static const struct of_device_id aspeed_bmc_device_of_matches[] = {
+	{ .compatible = "aspeed,ast2600-bmc-device", .data = &ast2600_plaform },
+	{},
+};
+MODULE_DEVICE_TABLE(of, aspeed_bmc_device_of_matches);
+
+static int aspeed_bmc_device_probe(struct platform_device *pdev)
+{
+	struct aspeed_bmc_device *bmc_device;
+	struct device *dev = &pdev->dev;
+	const void *md = of_device_get_match_data(dev);
+	int ret = 0;
+
+	if (!md)
+		return -ENODEV;
+
+	bmc_device = devm_kzalloc(&pdev->dev, sizeof(struct aspeed_bmc_device), GFP_KERNEL);
+	if (!bmc_device)
+		return -ENOMEM;
+	dev_set_drvdata(dev, bmc_device);
+
+	bmc_device->platform = md;
+
+	bmc_device->id = of_alias_get_id(dev->of_node, "bmcdev");
+	if (bmc_device->id < 0)
+		bmc_device->id = 0;
+
+	bmc_device->dev = dev;
+	bmc_device->reg_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(bmc_device->reg_base))
+		return PTR_ERR(bmc_device->reg_base);
+
+	bmc_device->irq = platform_get_irq(pdev, 0);
+	if (bmc_device->irq < 0) {
+		dev_err(&pdev->dev, "platform get of irq[=%d] failed!\n", bmc_device->irq);
+		return bmc_device->irq;
+	}
+
+	if (of_property_read_bool(dev->of_node, "pcie2lpc"))
+		bmc_device->pcie2lpc = 1;
+
+	ret = bmc_device->platform->init(pdev);
+	if (ret) {
+		dev_err(dev, "Initialize bmc device failed\n");
+		goto out;
+	}
+
+	dev_info(dev, "aspeed bmc device: driver successfully loaded.\n");
+
+	return 0;
+
+out:
+	dev_warn(dev, "aspeed bmc device: driver init failed (ret=%d)!\n", ret);
+	return ret;
+}
+
+static void aspeed_bmc_device_remove(struct platform_device *pdev)
+{
+	struct aspeed_bmc_device *bmc_device = platform_get_drvdata(pdev);
+
+	devm_free_irq(&pdev->dev, bmc_device->irq, bmc_device);
+	devm_kfree(&pdev->dev, bmc_device);
+}
+
+static struct platform_driver aspeed_bmc_device_driver = {
+	.probe		= aspeed_bmc_device_probe,
+	.remove		= aspeed_bmc_device_remove,
+	.driver		= {
+		.name	= KBUILD_MODNAME,
+		.of_match_table = aspeed_bmc_device_of_matches,
+	},
+};
+
+module_platform_driver(aspeed_bmc_device_driver);
+
+MODULE_AUTHOR("Ryan Chen <[email protected]>");
+MODULE_DESCRIPTION("ASPEED BMC DEVICE Driver");
+MODULE_LICENSE("GPL");
\ No newline at end of file
-- 
2.51.2