mfd: Add support for Merrifield Basin Cove PMIC

Add an MFD driver for Intel Merrifield Basin Cove PMIC.

Firmware on the platforms which are using Basin Cove PMIC is "smarter"
than on the rest supported by vanilla kernel. It handles first level
of interrupt itself, while others do it on OS level.

The driver is done in the same way as the rest of Intel PMIC MFD drivers
in the kernel to support the initial design. The design allows to use
one driver among few PMICs without knowing implementation details of
the each hardware version or generation.

Signed-off-by: Andy Shevchenko <[email protected]>
Signed-off-by: Lee Jones <[email protected]>

drivers/mfd/Kconfig

@@ -597,6 +597,17 @@ config INTEL_SOC_PMIC_CHTDC_TI
 	  Select this option for supporting Dollar Cove (TI version) PMIC
 	  device that is found on some Intel Cherry Trail systems.
 
+config INTEL_SOC_PMIC_MRFLD
+	tristate "Support for Intel Merrifield Basin Cove PMIC"
+	depends on GPIOLIB
+	depends on ACPI
+	depends on INTEL_SCU_IPC
+	select MFD_CORE
+	select REGMAP_IRQ
+	help
+	  Select this option for supporting Basin Cove PMIC device
+	  that is found on Intel Merrifield systems.
+
 config MFD_INTEL_LPSS
 	tristate
 	select COMMON_CLK

drivers/mfd/Makefile

@@ -242,6 +242,7 @@ obj-$(CONFIG_INTEL_SOC_PMIC_CHTWC)	+= intel_soc_pmic_chtwc.o
 obj-$(CONFIG_INTEL_SOC_PMIC_CHTDC_TI)	+= intel_soc_pmic_chtdc_ti.o
 mt6397-objs	:= mt6397-core.o mt6397-irq.o
 obj-$(CONFIG_MFD_MT6397)	+= mt6397.o
+obj-$(CONFIG_INTEL_SOC_PMIC_MRFLD)	+= intel_soc_pmic_mrfld.o
 
 obj-$(CONFIG_MFD_ALTERA_A10SR)	+= altera-a10sr.o
 obj-$(CONFIG_MFD_ALTERA_SYSMGR) += altera-sysmgr.o

drivers/mfd/intel_soc_pmic_mrfld.c

@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Device access for Basin Cove PMIC
+ *
+ * Copyright (c) 2019, Intel Corporation.
+ * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ */
+
+#include <linux/acpi.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/intel_soc_pmic.h>
+#include <linux/mfd/intel_soc_pmic_mrfld.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include <asm/intel_scu_ipc.h>
+
+/*
+ * Level 2 IRQs
+ *
+ * Firmware on the systems with Basin Cove PMIC services Level 1 IRQs
+ * without an assistance. Thus, each of the Level 1 IRQ is represented
+ * as a separate RTE in IOAPIC.
+ */
+static struct resource irq_level2_resources[] = {
+	DEFINE_RES_IRQ(0), /* power button */
+	DEFINE_RES_IRQ(0), /* TMU */
+	DEFINE_RES_IRQ(0), /* thermal */
+	DEFINE_RES_IRQ(0), /* BCU */
+	DEFINE_RES_IRQ(0), /* ADC */
+	DEFINE_RES_IRQ(0), /* charger */
+	DEFINE_RES_IRQ(0), /* GPIO */
+};
+
+static const struct mfd_cell bcove_dev[] = {
+	{
+		.name = "mrfld_bcove_pwrbtn",
+		.num_resources = 1,
+		.resources = &irq_level2_resources[0],
+	}, {
+		.name = "mrfld_bcove_tmu",
+		.num_resources = 1,
+		.resources = &irq_level2_resources[1],
+	}, {
+		.name = "mrfld_bcove_thermal",
+		.num_resources = 1,
+		.resources = &irq_level2_resources[2],
+	}, {
+		.name = "mrfld_bcove_bcu",
+		.num_resources = 1,
+		.resources = &irq_level2_resources[3],
+	}, {
+		.name = "mrfld_bcove_adc",
+		.num_resources = 1,
+		.resources = &irq_level2_resources[4],
+	}, {
+		.name = "mrfld_bcove_charger",
+		.num_resources = 1,
+		.resources = &irq_level2_resources[5],
+	}, {
+		.name = "mrfld_bcove_pwrsrc",
+		.num_resources = 1,
+		.resources = &irq_level2_resources[5],
+	}, {
+		.name = "mrfld_bcove_gpio",
+		.num_resources = 1,
+		.resources = &irq_level2_resources[6],
+	},
+	{	.name = "mrfld_bcove_region", },
+};
+
+static int bcove_ipc_byte_reg_read(void *context, unsigned int reg,
+				    unsigned int *val)
+{
+	u8 ipc_out;
+	int ret;
+
+	ret = intel_scu_ipc_ioread8(reg, &ipc_out);
+	if (ret)
+		return ret;
+
+	*val = ipc_out;
+	return 0;
+}
+
+static int bcove_ipc_byte_reg_write(void *context, unsigned int reg,
+				     unsigned int val)
+{
+	u8 ipc_in = val;
+	int ret;
+
+	ret = intel_scu_ipc_iowrite8(reg, ipc_in);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static const struct regmap_config bcove_regmap_config = {
+	.reg_bits = 16,
+	.val_bits = 8,
+	.max_register = 0xff,
+	.reg_write = bcove_ipc_byte_reg_write,
+	.reg_read = bcove_ipc_byte_reg_read,
+};
+
+static int bcove_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct intel_soc_pmic *pmic;
+	unsigned int i;
+	int ret;
+
+	pmic = devm_kzalloc(dev, sizeof(*pmic), GFP_KERNEL);
+	if (!pmic)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, pmic);
+	pmic->dev = &pdev->dev;
+
+	pmic->regmap = devm_regmap_init(dev, NULL, pmic, &bcove_regmap_config);
+	if (IS_ERR(pmic->regmap))
+		return PTR_ERR(pmic->regmap);
+
+	for (i = 0; i < ARRAY_SIZE(irq_level2_resources); i++) {
+		ret = platform_get_irq(pdev, i);
+		if (ret < 0)
+			return ret;
+
+		irq_level2_resources[i].start = ret;
+		irq_level2_resources[i].end = ret;
+	}
+
+	return devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
+				    bcove_dev, ARRAY_SIZE(bcove_dev),
+				    NULL, 0, NULL);
+}
+
+static const struct acpi_device_id bcove_acpi_ids[] = {
+	{ "INTC100E" },
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, bcove_acpi_ids);
+
+static struct platform_driver bcove_driver = {
+	.driver = {
+		.name = "intel_soc_pmic_mrfld",
+		.acpi_match_table = bcove_acpi_ids,
+	},
+	.probe = bcove_probe,
+};
+module_platform_driver(bcove_driver);
+
+MODULE_DESCRIPTION("IPC driver for Intel SoC Basin Cove PMIC");
+MODULE_LICENSE("GPL v2");