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Date:   Mon, 10 May 2021 16:32:32 -0700
From:   Guru Das Srinagesh <gurus@codeaurora.org>
To:     Lee Jones <lee.jones@linaro.org>
Cc:     Rob Herring <robh+dt@kernel.org>, devicetree@vger.kernel.org,
        Mark Brown <broonie@kernel.org>,
        linux-arm-msm <linux-arm-msm@vger.kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 3/3] mfd: pm8008: Add driver for QCOM PM8008 PMIC
Message-ID: <20210510233232.GA22593@codeaurora.org>
References: <cover.1618278453.git.gurus@codeaurora.org>
 <a5d5f532ebd28f03b3236003a519adb68a979506.1618278453.git.gurus@codeaurora.org>
 <20210510155827.GB751702@dell>
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In-Reply-To: <20210510155827.GB751702@dell>
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On Mon, May 10, 2021 at 04:58:27PM +0100, Lee Jones wrote:
> On Mon, 12 Apr 2021, Guru Das Srinagesh wrote:
> 
> > Qualcomm Technologies, Inc. PM8008 is a dedicated camera PMIC that
> > integrates all the necessary power management, housekeeping, and
> > interface support functions into a single IC. Its key features include
> > overtemperature protection, low-dropout linear regulators, GPIOs, and an
> > I2C interface.
> > 
> > Add an MFD driver to support it.
> > 
> > Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
> > ---
> >  drivers/mfd/Kconfig       |  15 +++
> >  drivers/mfd/Makefile      |   1 +
> >  drivers/mfd/qcom-pm8008.c | 284 ++++++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 300 insertions(+)
> >  create mode 100644 drivers/mfd/qcom-pm8008.c
> > 
> > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> > index b74efa4..d75f937 100644
> > --- a/drivers/mfd/Kconfig
> > +++ b/drivers/mfd/Kconfig
> > @@ -2087,6 +2087,21 @@ config MFD_ACER_A500_EC
> >  	  The controller itself is ENE KB930, it is running firmware
> >  	  customized for the specific needs of the Acer A500 hardware.
> >  
> > +config MFD_QCOM_PM8008
> > +	tristate "QCOM PM8008 Power Management IC"
> > +	depends on I2C && OF
> > +	select REGMAP_I2C
> > +	select REGMAP_IRQ
> > +	help
> > +	  Select this option to get support for the Qualcomm Technologies, Inc.
> > +	  PM8008 PMIC chip. PM8008 is a dedicated camera PMIC that integrates
> > +	  all the necessary power management, housekeeping, and interface
> > +	  support functions into a single IC. This driver provides common
> > +	  support for accessing the device by instantiating all the child nodes
> > +	  under it in the device tree. Additional drivers must be enabled in
> > +	  order to use the functionality of the device.
> > +
> > +
> 
> Nit: No double-line spacings please.

Done.

> 
> >  menu "Multimedia Capabilities Port drivers"
> >  	depends on ARCH_SA1100
> >  
> > diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> > index 834f546..a5dda823 100644
> > --- a/drivers/mfd/Makefile
> > +++ b/drivers/mfd/Makefile
> > @@ -264,6 +264,7 @@ obj-$(CONFIG_MFD_ROHM_BD718XX)	+= rohm-bd718x7.o
> >  obj-$(CONFIG_MFD_STMFX) 	+= stmfx.o
> >  obj-$(CONFIG_MFD_KHADAS_MCU) 	+= khadas-mcu.o
> >  obj-$(CONFIG_MFD_ACER_A500_EC)	+= acer-ec-a500.o
> > +obj-$(CONFIG_MFD_QCOM_PM8008)	+= qcom-pm8008.o
> >  
> >  obj-$(CONFIG_SGI_MFD_IOC3)	+= ioc3.o
> >  obj-$(CONFIG_MFD_SIMPLE_MFD_I2C)	+= simple-mfd-i2c.o
> > diff --git a/drivers/mfd/qcom-pm8008.c b/drivers/mfd/qcom-pm8008.c
> > new file mode 100644
> > index 0000000..9315389
> > --- /dev/null
> > +++ b/drivers/mfd/qcom-pm8008.c
> > @@ -0,0 +1,284 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Copyright (c) 2021, The Linux Foundation. All rights reserved.
> > + */
> > +
> > +#include <linux/bitops.h>
> > +#include <linux/i2c.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/irq.h>
> > +#include <linux/irqdomain.h>
> > +#include <linux/module.h>
> > +#include <linux/of_platform.h>
> > +#include <linux/pinctrl/consumer.h>
> > +#include <linux/regmap.h>
> > +#include <linux/slab.h>
> > +#include <linux/of_device.h>
> 
> Alphabetical please.
> 
> '\n' here.

Done.

> 
> > +#include <dt-bindings/mfd/qcom-pm8008.h>
> > +
> > +#define I2C_INTR_STATUS_BASE	0x0550
> > +#define INT_RT_STS_OFFSET	0x10
> > +#define INT_SET_TYPE_OFFSET	0x11
> > +#define INT_POL_HIGH_OFFSET	0x12
> > +#define INT_POL_LOW_OFFSET	0x13
> > +#define INT_LATCHED_CLR_OFFSET	0x14
> > +#define INT_EN_SET_OFFSET	0x15
> > +#define INT_EN_CLR_OFFSET	0x16
> > +#define INT_LATCHED_STS_OFFSET	0x18
> 
> Can you tab these out so they all line up?

Done.

> 
> > +enum {
> > +	PM8008_MISC,
> > +	PM8008_TEMP_ALARM,
> > +	PM8008_GPIO1,
> > +	PM8008_GPIO2,
> > +	PM8008_NUM_PERIPHS,
> > +};
> > +
> > +#define PM8008_PERIPH_0_BASE	0x900
> > +#define PM8008_PERIPH_1_BASE	0x2400
> > +#define PM8008_PERIPH_2_BASE	0xC000
> > +#define PM8008_PERIPH_3_BASE	0xC100
> > +
> > +#define PM8008_TEMP_ALARM_ADDR	PM8008_PERIPH_1_BASE
> > +#define PM8008_GPIO1_ADDR	PM8008_PERIPH_2_BASE
> > +#define PM8008_GPIO2_ADDR	PM8008_PERIPH_3_BASE
> > +
> > +#define PM8008_STATUS_BASE	(PM8008_PERIPH_0_BASE | INT_LATCHED_STS_OFFSET)
> > +#define PM8008_MASK_BASE	(PM8008_PERIPH_0_BASE | INT_EN_SET_OFFSET)
> > +#define PM8008_UNMASK_BASE	(PM8008_PERIPH_0_BASE | INT_EN_CLR_OFFSET)
> > +#define PM8008_TYPE_BASE	(PM8008_PERIPH_0_BASE | INT_SET_TYPE_OFFSET)
> > +#define PM8008_ACK_BASE		(PM8008_PERIPH_0_BASE | INT_LATCHED_CLR_OFFSET)
> > +#define PM8008_POLARITY_HI_BASE	(PM8008_PERIPH_0_BASE | INT_POL_HIGH_OFFSET)
> > +#define PM8008_POLARITY_LO_BASE	(PM8008_PERIPH_0_BASE | INT_POL_LOW_OFFSET)
> > +
> > +#define ADDRESS_OFFSET(paddr, base)	(paddr - base)
> 
> No need for this.
> 
> > +#define PM8008_PERIPH_OFFSET(paddr)	\
> > +	ADDRESS_OFFSET(paddr, PM8008_PERIPH_0_BASE)
> 
> #define PM8008_PERIPH_OFFSET(paddr)	paddr - PM8008_PERIPH_0_BASE

Done.

> 
> > +struct pm8008_data {
> > +	struct device *dev;
> > +	struct regmap *regmap;
> > +	int irq;
> > +	struct regmap_irq_chip_data *irq_data;
> > +};
> > +
> > +static unsigned int p0_offs[] = {PM8008_PERIPH_OFFSET(PM8008_PERIPH_0_BASE)};
> > +static unsigned int p1_offs[] = {PM8008_PERIPH_OFFSET(PM8008_PERIPH_1_BASE)};
> > +static unsigned int p2_offs[] = {PM8008_PERIPH_OFFSET(PM8008_PERIPH_2_BASE)};
> > +static unsigned int p3_offs[] = {PM8008_PERIPH_OFFSET(PM8008_PERIPH_3_BASE)};
> > +
> > +static struct regmap_irq_sub_irq_map pm8008_sub_reg_offsets[] = {
> > +	REGMAP_IRQ_MAIN_REG_OFFSET(p0_offs),
> > +	REGMAP_IRQ_MAIN_REG_OFFSET(p1_offs),
> > +	REGMAP_IRQ_MAIN_REG_OFFSET(p2_offs),
> > +	REGMAP_IRQ_MAIN_REG_OFFSET(p3_offs),
> > +};
> > +
> > +static unsigned int pm8008_virt_regs[] = {
> > +	PM8008_POLARITY_HI_BASE,
> > +	PM8008_POLARITY_LO_BASE,
> > +};
> > +
> > +enum {
> > +	POLARITY_HI_INDEX,
> > +	POLARITY_LO_INDEX,
> > +	PM8008_NUM_VIRT_REGS,
> > +};
> > +
> > +static struct regmap_irq pm8008_irqs[] = {
> > +	/* MISC IRQs*/
> 
> Nit: Missing ' '.
> 
> Why are these comments required?  Isn't the nomenclature enough?

Removing comments as nomenclature is enough.

> 
> > +	REGMAP_IRQ_REG(PM8008_IRQ_MISC_UVLO,	PM8008_MISC,	BIT(0)),
> > +	REGMAP_IRQ_REG(PM8008_IRQ_MISC_OVLO,	PM8008_MISC,	BIT(1)),
> > +	REGMAP_IRQ_REG(PM8008_IRQ_MISC_OTST2,	PM8008_MISC,	BIT(2)),
> > +	REGMAP_IRQ_REG(PM8008_IRQ_MISC_OTST3,	PM8008_MISC,	BIT(3)),
> > +	REGMAP_IRQ_REG(PM8008_IRQ_MISC_LDO_OCP,	PM8008_MISC,	BIT(4)),
> > +	/* TEMP_ALARM IRQs */
> > +	REGMAP_IRQ_REG(PM8008_IRQ_TEMP_ALARM,	PM8008_TEMP_ALARM, BIT(0)),
> > +	/* GPIO1 IRQs */
> > +	REGMAP_IRQ_REG(PM8008_IRQ_GPIO1,	PM8008_GPIO1,	BIT(0)),
> > +	/* GPIO2 IRQs */
> > +	REGMAP_IRQ_REG(PM8008_IRQ_GPIO2,	PM8008_GPIO2,	BIT(0)),
> > +};
> > +
> > +static int pm8008_set_type_virt(unsigned int **virt_buf,
> > +				      unsigned int type, unsigned long hwirq,
> > +				      int reg)
> > +{
> > +	switch (type) {
> > +	case IRQ_TYPE_EDGE_FALLING:
> > +	case IRQ_TYPE_LEVEL_LOW:
> > +		virt_buf[POLARITY_HI_INDEX][reg] &= ~pm8008_irqs[hwirq].mask;
> > +		virt_buf[POLARITY_LO_INDEX][reg] |= pm8008_irqs[hwirq].mask;
> > +		break;
> > +
> 
> Not sure these '\n's add anything except more LoC.

I'd like to keep these newlines as I feel they improve readability.

> 
> > +	case IRQ_TYPE_EDGE_RISING:
> > +	case IRQ_TYPE_LEVEL_HIGH:
> > +		virt_buf[POLARITY_HI_INDEX][reg] |= pm8008_irqs[hwirq].mask;
> > +		virt_buf[POLARITY_LO_INDEX][reg] &= ~pm8008_irqs[hwirq].mask;
> > +		break;
> > +
> > +	case IRQ_TYPE_EDGE_BOTH:
> > +		virt_buf[POLARITY_HI_INDEX][reg] |= pm8008_irqs[hwirq].mask;
> > +		virt_buf[POLARITY_LO_INDEX][reg] |= pm8008_irqs[hwirq].mask;
> > +		break;
> > +
> > +	default:
> > +		return -EINVAL;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static struct regmap_irq_chip pm8008_irq_chip = {
> > +	.name			= "pm8008_irq",
> > +	.main_status		= I2C_INTR_STATUS_BASE,
> > +	.num_main_regs		= 1,
> > +	.num_virt_regs		= PM8008_NUM_VIRT_REGS,
> > +	.irqs			= pm8008_irqs,
> > +	.num_irqs		= ARRAY_SIZE(pm8008_irqs),
> > +	.num_regs		= PM8008_NUM_PERIPHS,
> > +	.not_fixed_stride	= true,
> > +	.sub_reg_offsets	= pm8008_sub_reg_offsets,
> > +	.set_type_virt		= pm8008_set_type_virt,
> > +	.status_base		= PM8008_STATUS_BASE,
> > +	.mask_base		= PM8008_MASK_BASE,
> > +	.unmask_base		= PM8008_UNMASK_BASE,
> > +	.type_base		= PM8008_TYPE_BASE,
> > +	.ack_base		= PM8008_ACK_BASE,
> > +	.virt_reg_base		= pm8008_virt_regs,
> > +	.num_type_reg		= PM8008_NUM_PERIPHS,
> > +};
> > +
> > +static struct regmap_config qcom_mfd_regmap_cfg = {
> > +	.reg_bits	= 16,
> > +	.val_bits	= 8,
> > +	.max_register	= 0xFFFF,
> > +};
> > +
> > +static int pm8008_init(struct pm8008_data *chip)
> > +{
> > +	int rc;
> > +
> > +	/*
> > +	 * Set TEMP_ALARM peripheral's TYPE so that the regmap-irq framework
> > +	 * reads this as the default value instead of zero, the HW default.
> > +	 * This is required to enable the writing of TYPE registers in
> > +	 * regmap_irq_sync_unlock().
> > +	 */
> > +	rc = regmap_write(chip->regmap,
> > +			 (PM8008_TEMP_ALARM_ADDR | INT_SET_TYPE_OFFSET),
> > +			 BIT(0));
> > +	if (rc)
> > +		return rc;
> > +
> > +	/* Do the same for GPIO1 and GPIO2 peripherals */
> > +	rc = regmap_write(chip->regmap,
> > +			 (PM8008_GPIO1_ADDR | INT_SET_TYPE_OFFSET), BIT(0));
> > +	if (rc)
> > +		return rc;
> > +
> > +	rc = regmap_write(chip->regmap,
> > +			 (PM8008_GPIO2_ADDR | INT_SET_TYPE_OFFSET), BIT(0));
> > +
> > +	return rc;
> > +}
> > +
> > +static int pm8008_probe_irq_peripherals(struct pm8008_data *chip,
> > +					int client_irq)
> > +{
> > +	int rc, i;
> > +	struct regmap_irq_type *type;
> > +	struct regmap_irq_chip_data *irq_data;
> > +
> > +	rc = pm8008_init(chip);
> > +	if (rc) {
> > +		dev_err(chip->dev, "Init failed: %d\n", rc);
> > +		return rc;
> > +	}
> > +
> > +	for (i = 0; i < ARRAY_SIZE(pm8008_irqs); i++) {
> > +		type = &pm8008_irqs[i].type;
> > +
> > +		type->type_reg_offset	  = pm8008_irqs[i].reg_offset;
> > +		type->type_rising_val	  = pm8008_irqs[i].mask;
> > +		type->type_falling_val	  = pm8008_irqs[i].mask;
> > +		type->type_level_high_val = 0;
> > +		type->type_level_low_val  = 0;
> > +
> > +		if (type->type_reg_offset == PM8008_MISC)
> > +			type->types_supported = IRQ_TYPE_EDGE_RISING;
> > +		else
> > +			type->types_supported = (IRQ_TYPE_EDGE_BOTH |
> > +				IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW);
> > +	}
> > +
> > +	rc = devm_regmap_add_irq_chip(chip->dev, chip->regmap, client_irq,
> > +			IRQF_SHARED, 0, &pm8008_irq_chip, &irq_data);
> > +	if (rc) {
> > +		dev_err(chip->dev, "Failed to add IRQ chip: %d\n", rc);
> > +		return rc;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int pm8008_probe(struct i2c_client *client,
> > +			     const struct i2c_device_id *id)
> > +{
> > +	int rc;
> > +	struct pm8008_data *chip;
> > +
> > +	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
> > +	if (!chip)
> > +		return -ENOMEM;
> > +
> > +	chip->dev = &client->dev;
> > +	chip->regmap = devm_regmap_init_i2c(client, &qcom_mfd_regmap_cfg);
> > +	if (!chip->regmap)
> > +		return -ENODEV;
> > +
> > +	i2c_set_clientdata(client, chip);
> > +	if (of_find_property(chip->dev->of_node, "interrupt-controller",
> > +			     NULL)) {
> 
> of_property_read_bool()
> 
> No need for this '\n' - place it all one line please.

Done.

> 
> > +		rc = pm8008_probe_irq_peripherals(chip, client->irq);
> > +		if (rc)
> > +			dev_err(chip->dev, "Failed to probe irq periphs: %d\n",
> > +				rc);
> 
> One line please.

Done (forgot that the 80-char limit has been increased now).

> 
> > +	}
> > +
> > +	return devm_of_platform_populate(chip->dev);
> > +}
> > +
> > +static int pm8008_remove(struct i2c_client *client)
> > +{
> > +	i2c_set_clientdata(client, NULL);
> 
> This should be done for you by the Device Driver core.

Sure, I'll just drop specifying a .remove driver callback then.

> 
> > +	return 0;
> > +}
> > +
> > +static const struct of_device_id pm8008_match[] = {
> > +	{ .compatible = "qcom,pm8008", },
> > +	{ },
> > +};
> > +
> > +static const struct i2c_device_id pm8008_id[] = {
> > +	{ "pm8008", 0 },
> > +	{ },
> > +};
> > +MODULE_DEVICE_TABLE(i2c, pm8008_id);
> 
> Use .probe_new, then you can omit this.

Done.

> 
> > +static struct i2c_driver pm8008_mfd_driver = {
> > +	.driver = {
> > +		.name = "mfd-pm8008",
> 
> No such thing as 'mfd', please drop that from the name.

Done; will simply use "pm8008" then.

> 
> > +		.of_match_table = pm8008_match,
> > +	},
> > +	.probe		= pm8008_probe,
> > +	.remove		= pm8008_remove,
> > +	.id_table	= pm8008_id,
> > +};
> > +module_i2c_driver(pm8008_mfd_driver);
> > +
> > +MODULE_LICENSE("GPL v2");
> > +MODULE_ALIAS("i2c:qcom-pm8008");

Thank you.

Guru Das.