mfd: tqmx86: IO controller with I2C, Wachdog and GPIO

The QMX86 is a PLD present on some TQ-Systems ComExpress modules. It
provides 1 or 2 I2C bus masters, 8 GPIOs and a watchdog timer. Add an
MFD which will instantiate the individual drivers.

Signed-off-by: Andrew Lunn <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>

drivers/mfd/Kconfig

···
 	help
 	  Support for Toshiba Mobile IO Controller TC6393XB
 
+config MFD_TQMX86
+	tristate "TQ-Systems IO controller TQMX86"
+	select MFD_CORE
+	help
+	  Say yes here to enable support for various functions of the
+	  TQ-Systems IO controller and watchdog device, found on their
+	  ComExpress CPU modules.
+
 config MFD_VX855
 	tristate "VIA VX855/VX875 integrated south bridge"
 	depends on PCI

drivers/mfd/Makefile

···
 obj-$(CONFIG_MFD_T7L66XB)	+= t7l66xb.o tmio_core.o
 obj-$(CONFIG_MFD_TC6387XB)	+= tc6387xb.o tmio_core.o
 obj-$(CONFIG_MFD_TC6393XB)	+= tc6393xb.o tmio_core.o
+obj-$(CONFIG_MFD_TQMX86)	+= tqmx86.o
 
 obj-$(CONFIG_MFD_LOCHNAGAR)	+= lochnagar-i2c.o
 

drivers/mfd/tqmx86.c

···
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * TQ-Systems PLD MFD core driver, based on vendor driver by
+ * Vadim V.Vlasov <[e-mail]>
+ *
+ * Copyright (c) 2015 TQ-Systems GmbH
+ * Copyright (c) 2019 Andrew Lunn <[e-mail]>
+ */
+
+#include <linux/delay.h>
+#include <linux/dmi.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/platform_data/i2c-ocores.h>
+#include <linux/platform_device.h>
+
+#define TQMX86_IOBASE	0x160
+#define TQMX86_IOSIZE	0x3f
+#define TQMX86_IOBASE_I2C	0x1a0
+#define TQMX86_IOSIZE_I2C	0xa
+#define TQMX86_IOBASE_WATCHDOG	0x18b
+#define TQMX86_IOSIZE_WATCHDOG	0x2
+#define TQMX86_IOBASE_GPIO	0x18d
+#define TQMX86_IOSIZE_GPIO	0x4
+
+#define TQMX86_REG_BOARD_ID	0x20
+#define TQMX86_REG_BOARD_ID_E38M	1
+#define TQMX86_REG_BOARD_ID_50UC	2
+#define TQMX86_REG_BOARD_ID_E38C	3
+#define TQMX86_REG_BOARD_ID_60EB	4
+#define TQMX86_REG_BOARD_ID_E39M	5
+#define TQMX86_REG_BOARD_ID_E39C	6
+#define TQMX86_REG_BOARD_ID_E39x	7
+#define TQMX86_REG_BOARD_ID_70EB	8
+#define TQMX86_REG_BOARD_ID_80UC	9
+#define TQMX86_REG_BOARD_ID_90UC	10
+#define TQMX86_REG_BOARD_REV	0x21
+#define TQMX86_REG_IO_EXT_INT	0x26
+#define TQMX86_REG_IO_EXT_INT_NONE		0
+#define TQMX86_REG_IO_EXT_INT_7			1
+#define TQMX86_REG_IO_EXT_INT_9			2
+#define TQMX86_REG_IO_EXT_INT_12		3
+#define TQMX86_REG_IO_EXT_INT_MASK		0x3
+#define TQMX86_REG_IO_EXT_INT_GPIO_SHIFT	4
+
+#define TQMX86_REG_I2C_DETECT	0x47
+#define TQMX86_REG_I2C_DETECT_SOFT		0xa5
+#define TQMX86_REG_I2C_INT_EN	0x49
+
+static uint gpio_irq;
+module_param(gpio_irq, uint, 0);
+MODULE_PARM_DESC(gpio_irq, "GPIO IRQ number (7, 9, 12)");
+
+static const struct resource tqmx_i2c_soft_resources[] = {
+	DEFINE_RES_IO(TQMX86_IOBASE_I2C, TQMX86_IOSIZE_I2C),
+};
+
+static const struct resource tqmx_watchdog_resources[] = {
+	DEFINE_RES_IO(TQMX86_IOBASE_WATCHDOG, TQMX86_IOSIZE_WATCHDOG),
+};
+
+/*
+ * The IRQ resource must be first, since it is updated with the
+ * configured IRQ in the probe function.
+ */
+static struct resource tqmx_gpio_resources[] = {
+	DEFINE_RES_IRQ(0),
+	DEFINE_RES_IO(TQMX86_IOBASE_GPIO, TQMX86_IOSIZE_GPIO),
+};
+
+static struct i2c_board_info tqmx86_i2c_devices[] = {
+	{
+		/* 4K EEPROM at 0x50 */
+		I2C_BOARD_INFO("24c32", 0x50),
+	},
+};
+
+static struct ocores_i2c_platform_data ocores_platfom_data = {
+	.num_devices = ARRAY_SIZE(tqmx86_i2c_devices),
+	.devices = tqmx86_i2c_devices,
+};
+
+static const struct mfd_cell tqmx86_i2c_soft_dev[] = {
+	{
+		.name = "ocores-i2c",
+		.platform_data = &ocores_platfom_data,
+		.pdata_size = sizeof(ocores_platfom_data),
+		.resources = tqmx_i2c_soft_resources,
+		.num_resources = ARRAY_SIZE(tqmx_i2c_soft_resources),
+	},
+};
+
+static const struct mfd_cell tqmx86_devs[] = {
+	{
+		.name = "tqmx86-wdt",
+		.resources = tqmx_watchdog_resources,
+		.num_resources = ARRAY_SIZE(tqmx_watchdog_resources),
+		.ignore_resource_conflicts = true,
+	},
+	{
+		.name = "tqmx86-gpio",
+		.resources = tqmx_gpio_resources,
+		.num_resources = ARRAY_SIZE(tqmx_gpio_resources),
+		.ignore_resource_conflicts = true,
+	},
+};
+
+static const char *tqmx86_board_id_to_name(u8 board_id)
+{
+	switch (board_id) {
+	case TQMX86_REG_BOARD_ID_E38M:
+		return "TQMxE38M";
+	case TQMX86_REG_BOARD_ID_50UC:
+		return "TQMx50UC";
+	case TQMX86_REG_BOARD_ID_E38C:
+		return "TQMxE38C";
+	case TQMX86_REG_BOARD_ID_60EB:
+		return "TQMx60EB";
+	case TQMX86_REG_BOARD_ID_E39M:
+		return "TQMxE39M";
+	case TQMX86_REG_BOARD_ID_E39C:
+		return "TQMxE39C";
+	case TQMX86_REG_BOARD_ID_E39x:
+		return "TQMxE39x";
+	case TQMX86_REG_BOARD_ID_70EB:
+		return "TQMx70EB";
+	case TQMX86_REG_BOARD_ID_80UC:
+		return "TQMx80UC";
+	case TQMX86_REG_BOARD_ID_90UC:
+		return "TQMx90UC";
+	default:
+		return "Unknown";
+	}
+}
+
+static int tqmx86_board_id_to_clk_rate(u8 board_id)
+{
+	switch (board_id) {
+	case TQMX86_REG_BOARD_ID_50UC:
+	case TQMX86_REG_BOARD_ID_60EB:
+	case TQMX86_REG_BOARD_ID_70EB:
+	case TQMX86_REG_BOARD_ID_80UC:
+	case TQMX86_REG_BOARD_ID_90UC:
+		return 24000;
+	case TQMX86_REG_BOARD_ID_E39M:
+	case TQMX86_REG_BOARD_ID_E39C:
+	case TQMX86_REG_BOARD_ID_E39x:
+		return 25000;
+	case TQMX86_REG_BOARD_ID_E38M:
+	case TQMX86_REG_BOARD_ID_E38C:
+		return 33000;
+	default:
+		return 0;
+	}
+}
+
+static int tqmx86_probe(struct platform_device *pdev)
+{
+	u8 board_id, rev, i2c_det, i2c_ien, io_ext_int_val;
+	struct device *dev = &pdev->dev;
+	u8 gpio_irq_cfg, readback;
+	const char *board_name;
+	void __iomem *io_base;
+	int err;
+
+	switch (gpio_irq) {
+	case 0:
+		gpio_irq_cfg = TQMX86_REG_IO_EXT_INT_NONE;
+		break;
+	case 7:
+		gpio_irq_cfg = TQMX86_REG_IO_EXT_INT_7;
+		break;
+	case 9:
+		gpio_irq_cfg = TQMX86_REG_IO_EXT_INT_9;
+		break;
+	case 12:
+		gpio_irq_cfg = TQMX86_REG_IO_EXT_INT_12;
+		break;
+	default:
+		pr_err("tqmx86: Invalid GPIO IRQ (%d)\n", gpio_irq);
+		return -EINVAL;
+	}
+
+	io_base = devm_ioport_map(dev, TQMX86_IOBASE, TQMX86_IOSIZE);
+	if (!io_base)
+		return -ENOMEM;
+
+	board_id = ioread8(io_base + TQMX86_REG_BOARD_ID);
+	board_name = tqmx86_board_id_to_name(board_id);
+	rev = ioread8(io_base + TQMX86_REG_BOARD_REV);
+
+	dev_info(dev,
+		 "Found %s - Board ID %d, PCB Revision %d, PLD Revision %d\n",
+		 board_name, board_id, rev >> 4, rev & 0xf);
+
+	i2c_det = ioread8(io_base + TQMX86_REG_I2C_DETECT);
+	i2c_ien = ioread8(io_base + TQMX86_REG_I2C_INT_EN);
+
+	if (gpio_irq_cfg) {
+		io_ext_int_val =
+			gpio_irq_cfg << TQMX86_REG_IO_EXT_INT_GPIO_SHIFT;
+		iowrite8(io_ext_int_val, io_base + TQMX86_REG_IO_EXT_INT);
+		readback = ioread8(io_base + TQMX86_REG_IO_EXT_INT);
+		if (readback != io_ext_int_val) {
+			dev_warn(dev, "GPIO interrupts not supported.\n");
+			return -EINVAL;
+		}
+
+		/* Assumes the IRQ resource is first. */
+		tqmx_gpio_resources[0].start = gpio_irq;
+	}
+
+	ocores_platfom_data.clock_khz = tqmx86_board_id_to_clk_rate(board_id);
+
+	if (i2c_det == TQMX86_REG_I2C_DETECT_SOFT) {
+		err = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
+					   tqmx86_i2c_soft_dev,
+					   ARRAY_SIZE(tqmx86_i2c_soft_dev),
+					   NULL, 0, NULL);
+		if (err)
+			return err;
+	}
+
+	return devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
+				    tqmx86_devs,
+				    ARRAY_SIZE(tqmx86_devs),
+				    NULL, 0, NULL);
+}
+
+static int tqmx86_create_platform_device(const struct dmi_system_id *id)
+{
+	struct platform_device *pdev;
+	int err;
+
+	pdev = platform_device_alloc("tqmx86", -1);
+	if (!pdev)
+		return -ENOMEM;
+
+	err = platform_device_add(pdev);
+	if (err)
+		platform_device_put(pdev);
+
+	return err;
+}
+
+static const struct dmi_system_id tqmx86_dmi_table[] __initconst = {
+	{
+		.ident = "TQMX86",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "TQ-Group"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "TQMx"),
+		},
+		.callback = tqmx86_create_platform_device,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(dmi, tqmx86_dmi_table);
+
+static struct platform_driver tqmx86_driver = {
+	.driver		= {
+		.name	= "tqmx86",
+	},
+	.probe		= tqmx86_probe,
+};
+
+static int __init tqmx86_init(void)
+{
+	if (!dmi_check_system(tqmx86_dmi_table))
+		return -ENODEV;
+
+	return platform_driver_register(&tqmx86_driver);
+}
+
+module_init(tqmx86_init);
+
+MODULE_DESCRIPTION("TQx86 PLD Core Driver");
+MODULE_AUTHOR("Andrew Lunn <[e-mail]>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:tqmx86");