[PATCH v9] 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

Changes in v5:
-Change Kconfig option from tristate to boolean and add a select for the
 i2c-bus driver, this is necessary because the chtwc PMIC provides an ACPI
 OPRegion handler, which must be available before other drivers using it
 are loaded, which can only be ensured if the mfd, opregion and i2c-bus
 drivers are built in. This fixes errors like these during boot:
 mmc0: SDHCI controller on ACPI [80860F14:00] using ADMA
 ACPI Error: No handler for Region [REGS] (ffff93543b0cc3a8) [UserDefinedRegion] (20170119/evregion-166)
 ACPI Error: Region UserDefinedRegion (ID=143) has no handler (20170119/exfldio-299)
 ACPI Error: Method parse/execution failed [\_SB.PCI0.I2C7.PMI5.GET] (Node ffff93543b0cde10), AE_NOT_EXIST (20170119/psparse-543)
 ACPI Error: Method parse/execution failed [\_SB.PCI0.SHC1._PS0] (Node ffff93543b0b5cd0), AE_NOT_EXIST (20170119/psparse-543)
 acpi 80860F14:02: Failed to change power state to D0
-Some minor style and capitalization fixes from review by Lee Jones

Changes in v6:
-Fix Kconfig depends and selects to fix warning reported by kbuild test robot

Changes in v7:
-Add explanation why this is a bool and why it selects i2c-designwaree
 to the help text rather then as comments in the Kconfig

Changes in v8:
-Remove MODULE macros, etc. now that this driver is a bool in Kconfig

Changes in v9:
-Some whitespace tweaks
-Return -EINVAL from probe on invalid irq
-Use probe_new i2c_driver callback
---
 drivers/mfd/Kconfig                |  17 +++
 drivers/mfd/Makefile               |   1 +
 drivers/mfd/intel_soc_pmic_chtwc.c | 230 +++++++++++++++++++++++++++++++++++++
 3 files changed, 248 insertions(+)
 create mode 100644 drivers/mfd/intel_soc_pmic_chtwc.c

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 3eb5c93595f6..5dfc9dcdc329 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -470,6 +470,23 @@ config INTEL_SOC_PMIC_BXTWC
 	  thermal, charger and related power management functions
 	  on these systems.
 
+config INTEL_SOC_PMIC_CHTWC
+	bool "Support for Intel Cherry Trail Whiskey Cove PMIC"
+	depends on ACPI && HAS_IOMEM
+	select MFD_CORE
+	select I2C
+	select REGMAP_I2C
+	select REGMAP_IRQ
+	select COMMON_CLK
+	select I2C_DESIGNWARE_PLATFORM
+	help
+	  Select this option to enable support for the Intel Cherry Trail
+	  Whiskey Cove PMIC found on some Intel Cherry Trail systems.
+
+	  This option is a bool as it provides an ACPI OpRegion which must be
+	  available before any devices using it are probed. This option also
+	  causes the designware-i2c driver to be builtin for the same reason.
+
 config MFD_INTEL_LPSS
 	tristate
 	select COMMON_CLK
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index c16bf1ea0ea9..6f6aed8cfccc 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -214,6 +214,7 @@ obj-$(CONFIG_MFD_SKY81452)	+= sky81452.o
 intel-soc-pmic-objs		:= intel_soc_pmic_core.o intel_soc_pmic_crc.o
 obj-$(CONFIG_INTEL_SOC_PMIC)	+= intel-soc-pmic.o
 obj-$(CONFIG_INTEL_SOC_PMIC_BXTWC)	+= intel_soc_pmic_bxtwc.o
+obj-$(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 000000000000..b35da01d5bcf
--- /dev/null
+++ b/drivers/mfd/intel_soc_pmic_chtwc.c
@@ -0,0 +1,230 @@
+/*
+ * 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 of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#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/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)
+{
+	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 -EINVAL;
+	}
+
+	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[] = {
+	{ }
+};
+
+static const struct acpi_device_id cht_wc_acpi_ids[] = {
+	{ "INT34D3", },
+	{ }
+};
+
+static struct i2c_driver cht_wc_driver = {
+	.driver	= {
+		.name	= "CHT Whiskey Cove PMIC",
+		.pm     = &cht_wc_pm_ops,
+		.acpi_match_table = cht_wc_acpi_ids,
+	},
+	.probe_new = cht_wc_probe,
+	.shutdown = cht_wc_shutdown,
+	.id_table = cht_wc_i2c_id,
+};
+builtin_i2c_driver(cht_wc_driver);
-- 
2.13.0