[PATCH v3 3/3] mfd: vortex: implement new driver for Vortex southbridges

[Marcos Del Sol Vives <marcos@orca.pet>]

This new driver loads resources related to southbridges available in DM&P
Vortex devices, currently only the GPIO pins.

Signed-off-by: Marcos Del Sol Vives <marcos@orca.pet>
---
 MAINTAINERS             |  1 +
 drivers/mfd/Kconfig     |  9 +++++
 drivers/mfd/Makefile    |  1 +
 drivers/mfd/vortex-sb.c | 81 +++++++++++++++++++++++++++++++++++++++++
 include/linux/pci_ids.h |  1 +
 5 files changed, 93 insertions(+)
 create mode 100644 drivers/mfd/vortex-sb.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 8c3098a39411..bc0c541309dd 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -26957,6 +26957,7 @@ VORTEX HARDWARE SUPPORT
 R:	Marcos Del Sol Vives <marcos@orca.pet>
 S:	Maintained
 F:	drivers/gpio/gpio-vortex.c
+F:	drivers/mfd/vortex-sb.c
 
 VRF
 M:	David Ahern <dsahern@kernel.org>
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 425c5fba6cb1..fe54bb22687d 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -2008,6 +2008,15 @@ config MFD_VX855
 	  VIA VX855/VX875 south bridge. You will need to enable the vx855_spi
 	  and/or vx855_gpio drivers for this to do anything useful.
 
+config MFD_VORTEX_SB
+	tristate "Vortex southbridge"
+	select MFD_CORE
+	depends on PCI
+	help
+	  Say yes here if you want to have support for the southbridge
+	  present on Vortex SoCs. You will need to enable the vortex-gpio
+	  driver for this to do anything useful.
+
 config MFD_ARIZONA
 	select REGMAP
 	select REGMAP_IRQ
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index f7bdedd5a66d..2504ba311f1a 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -202,6 +202,7 @@ obj-$(CONFIG_MFD_JANZ_CMODIO)	+= janz-cmodio.o
 obj-$(CONFIG_MFD_TPS6586X)	+= tps6586x.o
 obj-$(CONFIG_MFD_VX855)		+= vx855.o
 obj-$(CONFIG_MFD_WL1273_CORE)	+= wl1273-core.o
+obj-$(CONFIG_MFD_VORTEX_SB)	+= vortex-sb.o
 
 si476x-core-y := si476x-cmd.o si476x-prop.o si476x-i2c.o
 obj-$(CONFIG_MFD_SI476X_CORE)	+= si476x-core.o
diff --git a/drivers/mfd/vortex-sb.c b/drivers/mfd/vortex-sb.c
new file mode 100644
index 000000000000..ef9bbe2d3870
--- /dev/null
+++ b/drivers/mfd/vortex-sb.c
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  MFD southbridge driver for Vortex SoCs
+ *
+ *  Author: Marcos Del Sol Vives <marcos@orca.pet>
+ *
+ *  Based on the RDC321x MFD driver by Florian Fainelli and Bernhard Loos
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/pci.h>
+#include <linux/mfd/core.h>
+
+static const struct resource vortex_gpio_resources[] = {
+	{
+		.name	= "dat",
+		.start	= 0x78,
+		.end	= 0x7C,
+		.flags	= IORESOURCE_IO,
+	}, {
+		.name	= "dir",
+		.start	= 0x98,
+		.end	= 0x9C,
+		.flags	= IORESOURCE_IO,
+	}
+};
+
+static const struct mfd_cell vortex_sb_cells[] = {
+	{
+		.name		= "vortex-gpio",
+		.resources	= vortex_gpio_resources,
+		.num_resources	= ARRAY_SIZE(vortex_gpio_resources),
+	},
+};
+
+static int vortex_sb_probe(struct pci_dev *pdev,
+					const struct pci_device_id *ent)
+{
+	int err;
+
+	/*
+	 * In the Vortex86DX3, the southbridge appears twice (on both 00:07.0
+	 * and 00:07.1). Register only once for .0.
+	 *
+	 * Other Vortex boards (eg Vortex86MX+) have the southbridge exposed
+	 * only once, also at 00:07.0.
+	 */
+	if (PCI_FUNC(pdev->devfn) != 0)
+		return -ENODEV;
+
+	err = pci_enable_device(pdev);
+	if (err) {
+		dev_err(&pdev->dev, "failed to enable device\n");
+		return err;
+	}
+
+	return devm_mfd_add_devices(&pdev->dev, -1,
+				    vortex_sb_cells,
+				    ARRAY_SIZE(vortex_sb_cells),
+				    NULL, 0, NULL);
+}
+
+static const struct pci_device_id vortex_sb_table[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_RDC, PCI_DEVICE_ID_RDC_R6035) },
+	{}
+};
+MODULE_DEVICE_TABLE(pci, vortex_sb_table);
+
+static struct pci_driver vortex_sb_driver = {
+	.name		= "vortex-sb",
+	.id_table	= vortex_sb_table,
+	.probe		= vortex_sb_probe,
+};
+
+module_pci_driver(vortex_sb_driver);
+
+MODULE_AUTHOR("Marcos Del Sol Vives <marcos@orca.pet>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Vortex MFD southbridge driver");
diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
index 92ffc4373f6d..2ff8a593ef72 100644
--- a/include/linux/pci_ids.h
+++ b/include/linux/pci_ids.h
@@ -2412,6 +2412,7 @@
 #define PCI_VENDOR_ID_RDC		0x17f3
 #define PCI_DEVICE_ID_RDC_R6020		0x6020
 #define PCI_DEVICE_ID_RDC_R6030		0x6030
+#define PCI_DEVICE_ID_RDC_R6035		0x6035
 #define PCI_DEVICE_ID_RDC_R6040		0x6040
 #define PCI_DEVICE_ID_RDC_R6060		0x6060
 #define PCI_DEVICE_ID_RDC_R6061		0x6061
-- 
2.34.1