mfd: lpc_ich: Add support for pinctrl in non-ACPI system

Add support for non-ACPI systems, such as system that uses
Advanced Boot Loader (ABL) whereby a platform device has to be created
in order to bind with pin control and GPIO.

At the moment, Intel Apollo Lake In-Vehicle Infotainment (IVI) system
requires a driver to hide and unhide P2SB to lookup P2SB BAR and pass
the PCI BAR address to GPIO.
Signed-off-by: Tan Jui Nee <jui.nee.tan@intel.com>
Co-developed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Henning Schild <henning.schild@siemens.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lee Jones <lee@kernel.org>

drivers/mfd/lpc_ich.c

@@ -8,7 +8,8 @@
  *  Configuration Registers.
  *
  *  This driver is derived from lpc_sch.
-
+ *
+ *  Copyright (c) 2017, 2021-2022 Intel Corporation
  *  Copyright (c) 2011 Extreme Engineering Solution, Inc.
  *  Author: Aaron Sierra <asierra@xes-inc.com>
  *
@@ -42,6 +43,7 @@
 #include <linux/errno.h>
 #include <linux/acpi.h>
 #include <linux/pci.h>
+#include <linux/pinctrl/pinctrl.h>
 #include <linux/mfd/core.h>
 #include <linux/mfd/lpc_ich.h>
 #include <linux/platform_data/itco_wdt.h>
@@ -142,6 +144,73 @@ static struct mfd_cell lpc_ich_gpio_cell = {
 	.ignore_resource_conflicts = true,
 };
 
+#define APL_GPIO_NORTH		0
+#define APL_GPIO_NORTHWEST	1
+#define APL_GPIO_WEST		2
+#define APL_GPIO_SOUTHWEST	3
+#define APL_GPIO_NR_DEVICES	4
+
+/* Offset data for Apollo Lake GPIO controllers */
+static resource_size_t apl_gpio_offsets[APL_GPIO_NR_DEVICES] = {
+	[APL_GPIO_NORTH]	= 0xc50000,
+	[APL_GPIO_NORTHWEST]	= 0xc40000,
+	[APL_GPIO_WEST]		= 0xc70000,
+	[APL_GPIO_SOUTHWEST]	= 0xc00000,
+};
+
+#define APL_GPIO_RESOURCE_SIZE		0x1000
+
+#define APL_GPIO_IRQ			14
+
+static struct resource apl_gpio_resources[APL_GPIO_NR_DEVICES][2] = {
+	[APL_GPIO_NORTH] = {
+		DEFINE_RES_MEM(0, 0),
+		DEFINE_RES_IRQ(APL_GPIO_IRQ),
+	},
+	[APL_GPIO_NORTHWEST] = {
+		DEFINE_RES_MEM(0, 0),
+		DEFINE_RES_IRQ(APL_GPIO_IRQ),
+	},
+	[APL_GPIO_WEST] = {
+		DEFINE_RES_MEM(0, 0),
+		DEFINE_RES_IRQ(APL_GPIO_IRQ),
+	},
+	[APL_GPIO_SOUTHWEST] = {
+		DEFINE_RES_MEM(0, 0),
+		DEFINE_RES_IRQ(APL_GPIO_IRQ),
+	},
+};
+
+static const struct mfd_cell apl_gpio_devices[APL_GPIO_NR_DEVICES] = {
+	[APL_GPIO_NORTH] = {
+		.name = "apollolake-pinctrl",
+		.id = APL_GPIO_NORTH,
+		.num_resources = ARRAY_SIZE(apl_gpio_resources[APL_GPIO_NORTH]),
+		.resources = apl_gpio_resources[APL_GPIO_NORTH],
+		.ignore_resource_conflicts = true,
+	},
+	[APL_GPIO_NORTHWEST] = {
+		.name = "apollolake-pinctrl",
+		.id = APL_GPIO_NORTHWEST,
+		.num_resources = ARRAY_SIZE(apl_gpio_resources[APL_GPIO_NORTHWEST]),
+		.resources = apl_gpio_resources[APL_GPIO_NORTHWEST],
+		.ignore_resource_conflicts = true,
+	},
+	[APL_GPIO_WEST] = {
+		.name = "apollolake-pinctrl",
+		.id = APL_GPIO_WEST,
+		.num_resources = ARRAY_SIZE(apl_gpio_resources[APL_GPIO_WEST]),
+		.resources = apl_gpio_resources[APL_GPIO_WEST],
+		.ignore_resource_conflicts = true,
+	},
+	[APL_GPIO_SOUTHWEST] = {
+		.name = "apollolake-pinctrl",
+		.id = APL_GPIO_SOUTHWEST,
+		.num_resources = ARRAY_SIZE(apl_gpio_resources[APL_GPIO_SOUTHWEST]),
+		.resources = apl_gpio_resources[APL_GPIO_SOUTHWEST],
+		.ignore_resource_conflicts = true,
+	},
+};
 
 static struct mfd_cell lpc_ich_spi_cell = {
 	.name = "intel-spi",
@@ -1085,6 +1154,34 @@ static int lpc_ich_init_wdt(struct pci_dev *dev)
 	return ret;
 }
 
+static int lpc_ich_init_pinctrl(struct pci_dev *dev)
+{
+	struct resource base;
+	unsigned int i;
+	int ret;
+
+	/* Check, if GPIO has been exported as an ACPI device */
+	if (acpi_dev_present("INT3452", NULL, -1))
+		return -EEXIST;
+
+	ret = p2sb_bar(dev->bus, 0, &base);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < ARRAY_SIZE(apl_gpio_devices); i++) {
+		struct resource *mem = &apl_gpio_resources[i][0];
+		resource_size_t offset = apl_gpio_offsets[i];
+
+		/* Fill MEM resource */
+		mem->start = base.start + offset;
+		mem->end = base.start + offset + APL_GPIO_RESOURCE_SIZE - 1;
+		mem->flags = base.flags;
+	}
+
+	return mfd_add_devices(&dev->dev, 0, apl_gpio_devices,
+			       ARRAY_SIZE(apl_gpio_devices), NULL, 0, NULL);
+}
+
 static bool lpc_ich_byt_set_writeable(void __iomem *base, void *data)
 {
 	u32 val;
@@ -1235,6 +1332,12 @@ static int lpc_ich_probe(struct pci_dev *dev,
 			cell_added = true;
 	}
 
+	if (priv->chipset == LPC_APL) {
+		ret = lpc_ich_init_pinctrl(dev);
+		if (!ret)
+			cell_added = true;
+	}
+
 	if (lpc_chipset_info[priv->chipset].spi_type) {
 		ret = lpc_ich_init_spi(dev);
 		if (!ret)