[PATCH v2 1/3] mfd: Add Cherry Trail Whiskey Cove PMIC driver

[Hans de Goede]

Add mfd driver for Intel CHT Whiskey Cove PMIC, based on various non
upstreamed CHT Whiskey Cove PMIC patches.

This is a somewhat minimal version which adds irqchip support and cells
for: ACPI PMIC opregion support, the i2c-controller driving the external
charger irc and the pwrsrc/extcon block.

Further cells can be added in the future if/when drivers are upstreamed
for them.

Cc: Bin Gao <bin.gao@xxxxxxxxx>
Cc: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
Changes in v2:
-Since this uses plain mfd and not the intel_soc_pmic stuff give it
 its own Kconfig and allow this to be built as a module
-Add missing #include <acpi/acpi_bus.h>
Changes in v3:
-Drop #include <acpi/acpi_bus.h> again, not the right fix for the build errors
-Error out when the upper byte of the register-address passed to the regmap
 functions is 0 rather then hardcoding an address in that case
-Various minor style tweaks / cleanups
-Move defines of regulator register addresses to intel_pmic_chtwc.c,
 it is the only place where they are used
-Drop now empty include/linux/mfd/intel_chtwc.h
-Rename intel_soc_pmic_chtwc.c to intel_cht_wc.c to match Kconfig option name
-Add irqchip support
-Add external charger cell
-Add pwrsrc cell
Changes in v4:
-Use PLATFORM_DEVID_NONE
---
 drivers/mfd/Kconfig                |  11 ++
 drivers/mfd/Makefile               |   1 +
 drivers/mfd/intel_soc_pmic_chtwc.c | 244 +++++++++++++++++++++++++++++++++++++
 3 files changed, 256 insertions(+)
 create mode 100644 drivers/mfd/intel_soc_pmic_chtwc.c

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 55ecdfb..d427a10 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -437,6 +437,17 @@ config INTEL_SOC_PMIC
 	  thermal, charger and related power management functions
 	  on these systems.
 
+config INTEL_SOC_PMIC_CHTWC
+	tristate "Support for Intel Cherry Trail Whiskey Cove PMIC"
+	depends on ACPI
+	depends on I2C
+	select MFD_CORE
+	select REGMAP_I2C
+	select REGMAP_IRQ
+	help
+	  Select this option to enable support for the Intel Cherry Trail
+	  Whiskey Cove PMIC found on some Intel Cherry Trail systems.
+
 config MFD_INTEL_LPSS
 	tristate
 	select COMMON_CLK
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 31ce076..d2ca514 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -209,6 +209,7 @@ obj-$(CONFIG_MFD_SKY81452)	+= sky81452.o
 intel-soc-pmic-objs		:= intel_soc_pmic_core.o intel_soc_pmic_crc.o
 intel-soc-pmic-$(CONFIG_INTEL_PMC_IPC)	+= intel_soc_pmic_bxtwc.o
 obj-$(CONFIG_INTEL_SOC_PMIC)	+= intel-soc-pmic.o
+obj-$(CONFIG_INTEL_SOC_PMIC_CHTWC) += intel_soc_pmic_chtwc.o
 obj-$(CONFIG_MFD_MT6397)	+= mt6397-core.o
 
 obj-$(CONFIG_MFD_ALTERA_A10SR)	+= altera-a10sr.o
diff --git a/drivers/mfd/intel_soc_pmic_chtwc.c b/drivers/mfd/intel_soc_pmic_chtwc.c
new file mode 100644
index 0000000..50aec44
--- /dev/null
+++ b/drivers/mfd/intel_soc_pmic_chtwc.c
@@ -0,0 +1,244 @@
+/*
+ * MFD core driver for Intel Cherrytrail Whiskey Cove PMIC
+ * Copyright (C) 2017 Hans de Goede <hdegoede@xxxxxxxxxx>
+ *
+ * Based on various non upstream patches to support the CHT Whiskey Cove PMIC:
+ * Copyright (C) 2013-2015 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/intel_soc_pmic.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+/* PMIC device registers */
+#define REG_OFFSET_MASK		GENMASK(7, 0)
+#define REG_ADDR_MASK		GENMASK(15, 8)
+#define REG_ADDR_SHIFT		8
+
+#define CHT_WC_IRQLVL1		0x6e02
+#define CHT_WC_IRQLVL1_MASK	0x6e0e
+
+/* Whiskey Cove PMIC share same ACPI ID between different platforms */
+#define CHT_WC_HRV		3
+
+/* Level 1 IRQs (level 2 IRQs are handled in the child device drivers) */
+enum {
+	CHT_WC_PWRSRC_IRQ = 0,
+	CHT_WC_THRM_IRQ,
+	CHT_WC_BCU_IRQ,
+	CHT_WC_ADC_IRQ,
+	CHT_WC_EXT_CHGR_IRQ,
+	CHT_WC_GPIO_IRQ,
+	/* There is no irq 6 */
+	CHT_WC_CRIT_IRQ = 7,
+};
+
+static struct resource cht_wc_pwrsrc_resources[] = {
+	DEFINE_RES_IRQ(CHT_WC_PWRSRC_IRQ),
+};
+
+static struct resource cht_wc_ext_charger_resources[] = {
+	DEFINE_RES_IRQ(CHT_WC_EXT_CHGR_IRQ),
+};
+
+static struct mfd_cell cht_wc_dev[] = {
+	{
+		.name = "cht_wcove_pwrsrc",
+		.num_resources = ARRAY_SIZE(cht_wc_pwrsrc_resources),
+		.resources = cht_wc_pwrsrc_resources,
+	},
+	{
+		.name = "cht_wcove_ext_chgr",
+		.num_resources = ARRAY_SIZE(cht_wc_ext_charger_resources),
+		.resources = cht_wc_ext_charger_resources,
+	},
+	{
+		.name = "cht_wcove_region",
+	},
+};
+
+/*
+ * The CHT Whiskey Cove covers multiple i2c addresses, with a 1 byte
+ * register address space per i2c address, so we use 16 bit register
+ * addresses where the high 8 bits contain the i2c client address.
+ */
+static int cht_wc_byte_reg_read(void *context, unsigned int reg,
+				unsigned int *val)
+{
+	struct i2c_client *client = context;
+	int ret, orig_addr = client->addr;
+
+	if (!(reg & REG_ADDR_MASK)) {
+		dev_err(&client->dev, "Error i2c address not specified\n");
+		return -EINVAL;
+	}
+
+	client->addr = (reg & REG_ADDR_MASK) >> REG_ADDR_SHIFT;
+	ret = i2c_smbus_read_byte_data(client, reg & REG_OFFSET_MASK);
+	client->addr = orig_addr;
+
+	if (ret < 0)
+		return ret;
+
+	*val = ret;
+	return 0;
+}
+
+static int cht_wc_byte_reg_write(void *context, unsigned int reg,
+				 unsigned int val)
+{
+	struct i2c_client *client = context;
+	int ret, orig_addr = client->addr;
+
+	if (!(reg & REG_ADDR_MASK)) {
+		dev_err(&client->dev, "Error i2c address not specified\n");
+		return -EINVAL;
+	}
+
+	client->addr = (reg & REG_ADDR_MASK) >> REG_ADDR_SHIFT;
+	ret = i2c_smbus_write_byte_data(client, reg & REG_OFFSET_MASK, val);
+	client->addr = orig_addr;
+
+	return ret;
+}
+
+static const struct regmap_config cht_wc_regmap_cfg = {
+	.reg_bits = 16,
+	.val_bits = 8,
+	.reg_write = cht_wc_byte_reg_write,
+	.reg_read = cht_wc_byte_reg_read,
+};
+
+static const struct regmap_irq cht_wc_regmap_irqs[] = {
+	REGMAP_IRQ_REG(CHT_WC_PWRSRC_IRQ, 0, BIT(CHT_WC_PWRSRC_IRQ)),
+	REGMAP_IRQ_REG(CHT_WC_THRM_IRQ, 0, BIT(CHT_WC_THRM_IRQ)),
+	REGMAP_IRQ_REG(CHT_WC_BCU_IRQ, 0, BIT(CHT_WC_BCU_IRQ)),
+	REGMAP_IRQ_REG(CHT_WC_ADC_IRQ, 0, BIT(CHT_WC_ADC_IRQ)),
+	REGMAP_IRQ_REG(CHT_WC_EXT_CHGR_IRQ, 0, BIT(CHT_WC_EXT_CHGR_IRQ)),
+	REGMAP_IRQ_REG(CHT_WC_GPIO_IRQ, 0, BIT(CHT_WC_GPIO_IRQ)),
+	REGMAP_IRQ_REG(CHT_WC_CRIT_IRQ, 0, BIT(CHT_WC_CRIT_IRQ)),
+};
+
+static const struct regmap_irq_chip cht_wc_regmap_irq_chip = {
+	.name = "cht_wc_irq_chip",
+	.status_base = CHT_WC_IRQLVL1,
+	.mask_base = CHT_WC_IRQLVL1_MASK,
+	.irqs = cht_wc_regmap_irqs,
+	.num_irqs = ARRAY_SIZE(cht_wc_regmap_irqs),
+	.num_regs = 1,
+};
+
+static int cht_wc_probe(struct i2c_client *client,
+			const struct i2c_device_id *i2c_id)
+{
+	struct device *dev = &client->dev;
+	struct intel_soc_pmic *pmic;
+	acpi_status status;
+	unsigned long long hrv;
+	int ret;
+
+	status = acpi_evaluate_integer(ACPI_HANDLE(dev), "_HRV", NULL, &hrv);
+	if (ACPI_FAILURE(status)) {
+		dev_err(dev, "Failed to get PMIC hardware revision\n");
+		return -ENODEV;
+	}
+	if (hrv != CHT_WC_HRV) {
+		dev_err(dev, "Invalid PMIC hardware revision: %llu\n", hrv);
+		return -ENODEV;
+	}
+	if (client->irq < 0) {
+		dev_err(dev, "Invalid IRQ\n");
+		return -ENODEV;
+	}
+
+	pmic = devm_kzalloc(dev, sizeof(*pmic), GFP_KERNEL);
+	if (!pmic)
+		return -ENOMEM;
+
+	pmic->irq = client->irq;
+	pmic->dev = dev;
+	i2c_set_clientdata(client, pmic);
+
+	pmic->regmap = devm_regmap_init(dev, NULL, client, &cht_wc_regmap_cfg);
+	if (IS_ERR(pmic->regmap))
+		return PTR_ERR(pmic->regmap);
+
+	ret = devm_regmap_add_irq_chip(dev, pmic->regmap, pmic->irq,
+				       IRQF_ONESHOT | IRQF_SHARED, 0,
+				       &cht_wc_regmap_irq_chip,
+				       &pmic->irq_chip_data);
+	if (ret)
+		return ret;
+
+	return devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
+				cht_wc_dev, ARRAY_SIZE(cht_wc_dev), NULL, 0,
+				regmap_irq_get_domain(pmic->irq_chip_data));
+}
+
+static void cht_wc_shutdown(struct i2c_client *client)
+{
+	struct intel_soc_pmic *pmic = i2c_get_clientdata(client);
+
+	disable_irq(pmic->irq);
+}
+
+static int __maybe_unused cht_wc_suspend(struct device *dev)
+{
+	struct intel_soc_pmic *pmic = dev_get_drvdata(dev);
+
+	disable_irq(pmic->irq);
+	return 0;
+}
+
+static int __maybe_unused cht_wc_resume(struct device *dev)
+{
+	struct intel_soc_pmic *pmic = dev_get_drvdata(dev);
+
+	enable_irq(pmic->irq);
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(cht_wc_pm_ops, cht_wc_suspend, cht_wc_resume);
+
+static const struct i2c_device_id cht_wc_i2c_id[] = {
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, cht_wc_i2c_id);
+
+static const struct acpi_device_id cht_wc_acpi_ids[] = {
+	{ "INT34D3", },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, cht_wc_acpi_ids);
+
+static struct i2c_driver cht_wc_driver = {
+	.driver	= {
+		.name	= "CHT Whiskey Cove PMIC",
+		.pm     = &cht_wc_pm_ops,
+		.acpi_match_table = ACPI_PTR(cht_wc_acpi_ids),
+	},
+	.probe = cht_wc_probe,
+	.shutdown = cht_wc_shutdown,
+	.id_table = cht_wc_i2c_id,
+};
+
+module_i2c_driver(cht_wc_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Hans de Goede <hdegoede@xxxxxxxxxx>");
-- 
2.9.3