[PATCH v5 4/6] soc: mfd: add ASPEED AST2600 PCIe BMC device driver

@@ -4011,6 +4011,12 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/crypto/aspeed,*
 F:	drivers/crypto/aspeed/
 
+ASPEED PCI BMC DEVICE DRIVER
+M:	Grégoire Layet <git@gregoirelayet.com>
+M:	Tan Siewert <tan.siewert@9elements.com>
+S:	Maintained
+F:	drivers/mfd/aspeed-pci-core.c
+
 ASPEED PECI CONTROLLER
 M:	Iwona Winiarska <iwona.winiarska@intel.com>
 L:	linux-aspeed@lists.ozlabs.org (moderated for non-subscribers)

@@ -2573,5 +2573,17 @@ config MFD_MAX7360
 	  additional drivers must be enabled in order to use the functionality
 	  of the device.
 
+config MFD_ASPEED_PCI_BMC_DEVICE
+	tristate "ASPEED BMC PCIe device"
+	depends on PCI
+	select MFD_CORE
+	help
+	  Host-side driver for the ASPEED AST2600 BMC PCIe device found on
+	  BMC expansion cards. Exposes two 8250-compatible VUART
+	  ports.
+
+	  If unsure, say N. Choose M here if this machine has an
+	  AST2600-based BMC expansion card on its PCIe bus.
+
 endmenu
 endif

@@ -303,3 +303,5 @@ obj-$(CONFIG_MFD_RSMU_SPI)	+= rsmu_spi.o rsmu_core.o
 obj-$(CONFIG_MFD_UPBOARD_FPGA)	+= upboard-fpga.o
 
 obj-$(CONFIG_MFD_LOONGSON_SE)	+= loongson-se.o
+
+obj-$(CONFIG_MFD_ASPEED_PCI_BMC_DEVICE)	+= aspeed-pci-core.o

@@ -0,0 +1,120 @@
+// 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/pci.h>
+#include <linux/serial_8250.h>
+#include <linux/mfd/core.h>
+
+#define ASPEED_BMC_MULTI_MSI		32
+#define ASPEED_BMC_PCI_DEVICE_ID	0x2402
+#define ASPEED_BMC_REVISION_AST2700	0x27
+#define ASPEED_BMC_VUART		2
+
+#define DRIVER_NAME "ast2600-pci-core"
+
+static const unsigned int vuart_msi_index[ASPEED_BMC_VUART] = { 16, 17 };
+static const u16 vuart_port_addr[ASPEED_BMC_VUART] = { 0x3f8, 0x2f8 };
+
+struct aspeed_pci_bmc_dev {
+	struct plat_serial8250_port uart[ASPEED_BMC_VUART + 1];
+	struct mfd_cell cell;
+};
+
+static int aspeed_pci_bmc_device_setup_vuart(struct pci_dev *pdev,
+					     struct aspeed_pci_bmc_dev *pci_bmc_dev)
+{
+	resource_size_t bar = pci_resource_start(pdev, 1);
+	struct plat_serial8250_port *port;
+	u16 vuart_ioport;
+	unsigned int i;
+
+	for (i = 0; i < ASPEED_BMC_VUART; i++) {
+		port = &pci_bmc_dev->uart[i];
+
+		/* ASPEED BMC device shift addresses by 2 to the left */
+		vuart_ioport = vuart_port_addr[i] << 2;
+
+		port->mapbase = bar + vuart_ioport;
+		port->uartclk = 115200 * 16;
+		port->irq = pci_irq_vector(pdev, vuart_msi_index[i]);
+		port->iotype = UPIO_MEM32;
+		port->type = PORT_16550A;
+		port->flags |= (UPF_IOREMAP | UPF_FIXED_PORT | UPF_FIXED_TYPE);
+		port->regshift = 2;
+	}
+
+	pci_bmc_dev->cell = (struct mfd_cell) {
+		.name		= "serial8250",
+		.platform_data	= pci_bmc_dev->uart,
+		.pdata_size	= sizeof(pci_bmc_dev->uart),
+	};
+
+	return 0;
+}
+
+static void aspeed_bmc_pci_free_irqs(void *pdev)
+{
+	pci_free_irq_vectors(pdev);
+}
+
+static int aspeed_pci_host_bmc_device_probe(struct pci_dev *pdev,
+					    const struct pci_device_id *ent)
+{
+	struct device *dev = &pdev->dev;
+	struct aspeed_pci_bmc_dev *pci_bmc_dev;
+	int rc = 0;
+
+	if (pdev->revision == ASPEED_BMC_REVISION_AST2700)
+		return dev_err_probe(dev, -ENODEV, "AST2700 detected but not supported\n");
+
+	pci_bmc_dev = devm_kzalloc(dev, sizeof(*pci_bmc_dev), GFP_KERNEL);
+	if (!pci_bmc_dev)
+		return -ENOMEM;
+
+	rc = pcim_enable_device(pdev);
+	if (rc)
+		return dev_err_probe(dev, rc, "failed to enable device\n");
+
+	pci_set_master(pdev);
+
+	rc = pci_alloc_irq_vectors(pdev, ASPEED_BMC_MULTI_MSI, ASPEED_BMC_MULTI_MSI, PCI_IRQ_MSI);
+	if (rc < 0)
+		return dev_err_probe(dev, rc, "failed to allocate %d MSI vectors\n",
+				     ASPEED_BMC_MULTI_MSI);
+
+	rc = devm_add_action_or_reset(dev, aspeed_bmc_pci_free_irqs, pdev);
+	if (rc)
+		return rc;
+
+	aspeed_pci_bmc_device_setup_vuart(pdev, pci_bmc_dev);
+
+	return devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO,
+				    &pci_bmc_dev->cell, 1, &pdev->resource[1],
+				    0, NULL);
+}
+
+static struct pci_device_id aspeed_bmc_dev_pci_ids[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_ASPEED, ASPEED_BMC_PCI_DEVICE_ID),
+		.class = PCI_CLASS_OTHERS << 16,
+		.class_mask = 0xFFFF00
+	},
+	{ 0 }
+};
+
+MODULE_DEVICE_TABLE(pci, aspeed_bmc_dev_pci_ids);
+
+static struct pci_driver aspeed_host_bmc_dev_driver = {
+	.name		= DRIVER_NAME,
+	.id_table	= aspeed_bmc_dev_pci_ids,
+	.probe		= aspeed_pci_host_bmc_device_probe,
+};
+
+module_pci_driver(aspeed_host_bmc_dev_driver);
+
+MODULE_AUTHOR("Grégoire Layet <gregoire.layet@9elements.com>");
+MODULE_DESCRIPTION("Host-side driver for the ASPEED BMC PCIe device");
+MODULE_LICENSE("GPL");