Re: [PATCH v8] mfd: Add Cherry Trail Whiskey Cove PMIC driver

[Lee Jones]

On Tue, 23 May 2017, Hans de Goede wrote:

> 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

This isn't the most readable changelog format I've ever seen.

> ---
>  drivers/mfd/Kconfig                |  17 +++
>  drivers/mfd/Makefile               |   1 +
>  drivers/mfd/intel_soc_pmic_chtwc.c | 233 +++++++++++++++++++++++++++++++++++++
>  3 files changed, 251 insertions(+)
>  create mode 100644 drivers/mfd/intel_soc_pmic_chtwc.c
> 
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 3eb5c93..1b6a83a 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 c16bf1e..6f6aed8 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 0000000..5b720a5
> --- /dev/null
> +++ b/drivers/mfd/intel_soc_pmic_chtwc.c
> @@ -0,0 +1,233 @@
> +/*
> + * MFD core driver for Intel Cherrytrail Whiskey Cove PMIC

Nit: '\n'

> + * 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,
> +	},
> +	{

Nit: Please place the previous 2 lines on a single line.

> +		.name = "cht_wcove_ext_chgr",
> +		.num_resources = ARRAY_SIZE(cht_wc_ext_charger_resources),
> +		.resources = cht_wc_ext_charger_resources,
> +	},
> +	{
> +		.name = "cht_wcove_region",
> +	},

Place the previous 3 lines on a single line, since this is a single
line entry.

> +};
> +
> +/*
> + * 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;

This should probably be -EINVAL or similar, since we *did* find a
device with the correct H/W revision.

> +	}
> +
> +	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);

Nit: '\n'

> +	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);

Nit: '\n'

> +	return 0;
> +}
> +

Remove this line.

> +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[] = {
> +	{ }
> +};

What's the point in this empty table?

> +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 = ACPI_PTR(cht_wc_acpi_ids),
> +	},
> +	.probe = cht_wc_probe,
> +	.shutdown = cht_wc_shutdown,
> +	.id_table = cht_wc_i2c_id,
> +};
> +

Remove this line.

> +builtin_i2c_driver(cht_wc_driver);

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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