Message-ID: <20160912091829.GB1873@dell>
Date:   Mon, 12 Sep 2016 10:18:29 +0100
From:   Lee Jones <lee.jones@...aro.org>
To:     Quentin Schulz <quentin.schulz@...e-electrons.com>
Cc:     jdelvare@...e.com, linux@...ck-us.net, jic23@...nel.org,
        knaack.h@....de, lars@...afoo.de, pmeerw@...erw.net,
        maxime.ripard@...e-electrons.com, wens@...e.org,
        thomas.petazzoni@...e-electrons.com,
        antoine.tenart@...e-electrons.com, linux-kernel@...r.kernel.org,
        linux-hwmon@...r.kernel.org, linux-iio@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH v5 2/3] mfd: add support for Allwinner SoCs ADC

On Thu, 08 Sep 2016, Quentin Schulz wrote:

> The Allwinner SoCs all have an ADC that can also act as a touchscreen
> controller and a thermal sensor. For now, only the ADC and the thermal
> sensor drivers are probed by the MFD, the touchscreen controller support
> will be added later.
> 
> Signed-off-by: Quentin Schulz <quentin.schulz@...e-electrons.com>
> ---
> 
> v5:
>  - correct mail address,
> 
> v4:
>  - rename files and variables from sunxi* to sun4i*,
>  - rename defines from SUNXI_* to SUN4I_* or SUN6I_*,
>  - remove TP in defines name,
>  - rename SUNXI_IRQ_* to SUN4I_GPADC_IRQ_* for consistency,
>  - use devm functions for regmap_add_irq_chip and mfd_add_devices,
>  - remove remove functions (now empty thanks to devm functions),
> 
> v3:
>  - use defines in regmap_irq instead of hard coded BITs,
>  - use of_device_id data field to chose which MFD cells to add considering
>    the compatible responsible of the MFD probe,
>  - remove useless initializations,
>  - disable all interrupts before adding them to regmap_irqchip,
>  - add goto error label in probe,
>  - correct wrapping in header license,
>  - move defines from IIO driver to header,
>  - use GENMASK to limit the size of the variable passed to a macro,
>  - prefix register BIT defines with the name of the register,
>  - reorder defines,
> 
> v2:
>  - add license headers,
>  - reorder alphabetically includes,
>  - add SUNXI_GPADC_ prefixes for defines,
> 
>  drivers/mfd/Kconfig                 |  15 ++++
>  drivers/mfd/Makefile                |   2 +
>  drivers/mfd/sun4i-gpadc-mfd.c       | 174 ++++++++++++++++++++++++++++++++++++
>  include/linux/mfd/sun4i-gpadc-mfd.h |  94 +++++++++++++++++++
>  4 files changed, 285 insertions(+)
>  create mode 100644 drivers/mfd/sun4i-gpadc-mfd.c
>  create mode 100644 include/linux/mfd/sun4i-gpadc-mfd.h
> 
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 1bcf601..95b3c3e 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -29,6 +29,21 @@ config MFD_ACT8945A
>  	  linear regulators, along with a complete ActivePath battery
>  	  charger.
>  
> +config MFD_SUN4I_GPADC
> +	tristate "Allwinner sunxi platforms' GPADC MFD driver"
> +	select MFD_CORE
> +	select REGMAP_MMIO
> +	depends on ARCH_SUNXI || COMPILE_TEST
> +	help
> +	  Select this to get support for Allwinner SoCs (A10, A13 and A31) ADC.
> +	  This driver will only map the hardware interrupt and registers, you
> +	  have to select individual drivers based on this MFD to be able to use
> +	  the ADC or the thermal sensor. This will try to probe the ADC driver
> +	  sun4i-gpadc-iio and the hwmon driver iio_hwmon.
> +
> +	  To compile this driver as a module, choose M here: the module will be
> +	  called sun4i-gpadc-mfd.

Drop the -mfd.

>  config MFD_AS3711
>  	bool "AMS AS3711"
>  	select MFD_CORE
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 42a66e1..3b964d7 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -205,3 +205,5 @@ 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-$(CONFIG_MFD_MT6397)	+= mt6397-core.o
> +
> +obj-$(CONFIG_MFD_SUN4I_GPADC)	+= sun4i-gpadc-mfd.o
> diff --git a/drivers/mfd/sun4i-gpadc-mfd.c b/drivers/mfd/sun4i-gpadc-mfd.c
> new file mode 100644
> index 0000000..b499545
> --- /dev/null
> +++ b/drivers/mfd/sun4i-gpadc-mfd.c

Drop the -mfd.

> @@ -0,0 +1,174 @@
> +/* ADC MFD core driver for sunxi platforms
> + *
> + * Copyright (c) 2016 Quentin Schulz <quentin.schulz@...e-electrons.com>
> + *
> + * 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/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/core.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/of_irq.h>
> +#include <linux/regmap.h>
> +
> +#include <linux/mfd/sun4i-gpadc-mfd.h>
> +
> +static struct resource adc_resources[] = {
> +	{
> +		.name	= "FIFO_DATA_PENDING",
> +		.start	= SUN4I_GPADC_IRQ_FIFO_DATA,
> +		.end	= SUN4I_GPADC_IRQ_FIFO_DATA,
> +		.flags	= IORESOURCE_IRQ,
> +	}, {
> +		.name	= "TEMP_DATA_PENDING",
> +		.start	= SUN4I_GPADC_IRQ_TEMP_DATA,
> +		.end	= SUN4I_GPADC_IRQ_TEMP_DATA,
> +		.flags	= IORESOURCE_IRQ,
> +	},
> +};

Use the RES_IRQ_* defines.

> +static const struct regmap_irq sun4i_gpadc_mfd_regmap_irq[] = {
> +	REGMAP_IRQ_REG(SUN4I_GPADC_IRQ_FIFO_DATA, 0,
> +		       SUN4I_GPADC_INT_FIFOC_TP_DATA_IRQ_EN),
> +	REGMAP_IRQ_REG(SUN4I_GPADC_IRQ_TEMP_DATA, 0,
> +		       SUN4I_GPADC_INT_FIFOC_TEMP_IRQ_EN),
> +};
> +
> +static const struct regmap_irq_chip sun4i_gpadc_mfd_regmap_irq_chip = {
> +	.name = "sun4i_gpadc_mfd_irq_chip",
> +	.status_base = SUN4I_GPADC_INT_FIFOS,
> +	.ack_base = SUN4I_GPADC_INT_FIFOS,
> +	.mask_base = SUN4I_GPADC_INT_FIFOC,
> +	.init_ack_masked = true,
> +	.mask_invert = true,
> +	.irqs = sun4i_gpadc_mfd_regmap_irq,
> +	.num_irqs = ARRAY_SIZE(sun4i_gpadc_mfd_regmap_irq),
> +	.num_regs = 1,
> +};
> +
> +static struct mfd_cell sun4i_gpadc_mfd_cells[] = {
> +	{
> +		.name	= "sun4i-a10-gpadc-iio",
> +		.resources = adc_resources,
> +		.num_resources = ARRAY_SIZE(adc_resources),
> +	}, {
> +		.name = "iio_hwmon",
> +	}

Single line please

{ .name = "iio_hwmon" }

> +};
> +
> +static struct mfd_cell sun5i_gpadc_mfd_cells[] = {
> +	{
> +		.name	= "sun5i-a13-gpadc-iio",
> +		.resources = adc_resources,
> +		.num_resources = ARRAY_SIZE(adc_resources),
> +	}, {
> +		.name = "iio_hwmon",
> +	},
> +};

As above.

> +static struct mfd_cell sun6i_gpadc_mfd_cells[] = {
> +	{
> +		.name	= "sun6i-a31-gpadc-iio",
> +		.resources = adc_resources,
> +		.num_resources = ARRAY_SIZE(adc_resources),
> +	}, {
> +		.name = "iio_hwmon",
> +	},
> +};

As above.

> +static const struct regmap_config sun4i_gpadc_mfd_regmap_config = {
> +	.reg_bits = 32,
> +	.val_bits = 32,
> +	.reg_stride = 4,
> +	.fast_io = true,
> +};
> +
> +static const struct of_device_id sun4i_gpadc_mfd_of_match[] = {
> +	{
> +		.compatible = "allwinner,sun4i-a10-ts",
> +		.data = &sun4i_gpadc_mfd_cells,
> +	}, {
> +		.compatible = "allwinner,sun5i-a13-ts",
> +		.data = &sun5i_gpadc_mfd_cells,
> +	}, {
> +		.compatible = "allwinner,sun6i-a31-ts",
> +		.data = &sun6i_gpadc_mfd_cells,
> +	}, { /* sentinel */ }
> +};

Don't mix OF and MFD functionality.

Why don't you create a node for "iio_hwmon" and have
platform_of_populate() do your bidding?

> +static int sun4i_gpadc_mfd_probe(struct platform_device *pdev)

Remove all mention of "mfd" from this file.

(Accept the calls to the MFD API of course).

> +{
> +	struct sun4i_gpadc_mfd_dev *mfd_dev;
> +	struct resource *mem;
> +	const struct of_device_id *of_id;
> +	const struct mfd_cell *mfd_cells;
> +	unsigned int irq;
> +	int ret;
> +
> +	of_id = of_match_node(sun4i_gpadc_mfd_of_match, pdev->dev.of_node);
> +	if (!of_id)
> +		return -EINVAL;
> +
> +	mfd_dev = devm_kzalloc(&pdev->dev, sizeof(*mfd_dev), GFP_KERNEL);
> +	if (!mfd_dev)
> +		return -ENOMEM;
> +
> +	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	mfd_dev->regs = devm_ioremap_resource(&pdev->dev, mem);
> +	if (IS_ERR(mfd_dev->regs))
> +		return PTR_ERR(mfd_dev->regs);
> +
> +	mfd_dev->dev = &pdev->dev;
> +	dev_set_drvdata(mfd_dev->dev, mfd_dev);
> +
> +	mfd_dev->regmap = devm_regmap_init_mmio(mfd_dev->dev, mfd_dev->regs,
> +						&sun4i_gpadc_mfd_regmap_config);
> +	if (IS_ERR(mfd_dev->regmap)) {
> +		ret = PTR_ERR(mfd_dev->regmap);
> +		dev_err(&pdev->dev, "failed to init regmap: %d\n", ret);
> +		return ret;
> +	}
> +
> +	/* Disable all interrupts */
> +	regmap_write(mfd_dev->regmap, SUN4I_GPADC_INT_FIFOC, 0);
> +
> +	irq = platform_get_irq(pdev, 0);
> +	ret = devm_regmap_add_irq_chip(&pdev->dev, mfd_dev->regmap, irq,
> +				       IRQF_ONESHOT, 0,
> +				       &sun4i_gpadc_mfd_regmap_irq_chip,
> +				       &mfd_dev->regmap_irqc);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to add irq chip: %d\n", ret);
> +		return ret;
> +	}
> +
> +	mfd_cells = of_id->data;
> +	ret = devm_mfd_add_devices(mfd_dev->dev, 0, mfd_cells, 2, NULL, 0,
> +				   NULL);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to add MFD devices: %d\n", ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +MODULE_DEVICE_TABLE(of, sun4i_gpadc_mfd_of_match);

Place this directly under the table.

> +static struct platform_driver sun4i_gpadc_mfd_driver = {
> +	.driver = {
> +		.name = "sun4i-adc-mfd",
> +		.of_match_table = of_match_ptr(sun4i_gpadc_mfd_of_match),
> +	},
> +	.probe = sun4i_gpadc_mfd_probe,

No .remove?

> +};
> +
> +module_platform_driver(sun4i_gpadc_mfd_driver);
> +
> +MODULE_DESCRIPTION("Allwinner sunxi platforms' GPADC MFD core driver");
> +MODULE_AUTHOR("Quentin Schulz <quentin.schulz@...e-electrons.com>");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/mfd/sun4i-gpadc-mfd.h b/include/linux/mfd/sun4i-gpadc-mfd.h
> new file mode 100644
> index 0000000..5cc7863
> --- /dev/null
> +++ b/include/linux/mfd/sun4i-gpadc-mfd.h
> @@ -0,0 +1,94 @@
> +/* Header of ADC MFD core driver for sunxi platforms
> + *
> + * Copyright (c) 2016 Quentin Schulz <quentin.schulz@...e-electrons.mfd>
> + *
> + * 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.
> + */
> +
> +#ifndef __SUN4I_GPADC_MFD__H__
> +#define __SUN4I_GPADC_MFD__H__
> +
> +#define SUN4I_GPADC_CTRL0				0x00
> +
> +#define SUN4I_GPADC_CTRL0_ADC_FIRST_DLY(x)		((GENMASK(7, 0) & (x)) << 24)
> +#define SUN4I_GPADC_CTRL0_ADC_FIRST_DLY_MODE		BIT(23)
> +#define SUN4I_GPADC_CTRL0_ADC_CLK_SELECT		BIT(22)
> +#define SUN4I_GPADC_CTRL0_ADC_CLK_DIVIDER(x)		((GENMASK(1, 0) & (x)) << 20)
> +#define SUN4I_GPADC_CTRL0_FS_DIV(x)			((GENMASK(3, 0) & (x)) << 16)
> +#define SUN4I_GPADC_CTRL0_T_ACQ(x)			(GENMASK(15, 0) & (x))
> +
> +#define SUN4I_GPADC_CTRL1				0x04
> +
> +#define SUN4I_GPADC_CTRL1_STYLUS_UP_DEBOUNCE(x)		((GENMASK(7, 0) & (x)) << 12)
> +#define SUN4I_GPADC_CTRL1_STYLUS_UP_DEBOUNCE_EN		BIT(9)
> +#define SUN4I_GPADC_CTRL1_TOUCH_PAN_CALI_EN		BIT(6)
> +#define SUN4I_GPADC_CTRL1_TP_DUAL_EN			BIT(5)
> +#define SUN4I_GPADC_CTRL1_TP_MODE_EN			BIT(4)
> +#define SUN4I_GPADC_CTRL1_TP_ADC_SELECT			BIT(3)
> +#define SUN4I_GPADC_CTRL1_ADC_CHAN_SELECT(x)		(GENMASK(2, 0) & (x))
> +
> +/* TP_CTRL1 bits for sun6i SOCs */
> +#define SUN6I_GPADC_CTRL1_TOUCH_PAN_CALI_EN		BIT(7)
> +#define SUN6I_GPADC_CTRL1_TP_DUAL_EN			BIT(6)
> +#define SUN6I_GPADC_CTRL1_TP_MODE_EN			BIT(5)
> +#define SUN6I_GPADC_CTRL1_TP_ADC_SELECT			BIT(4)
> +#define SUN6I_GPADC_CTRL1_ADC_CHAN_SELECT(x)		(GENMASK(3, 0) & BIT(x))
> +
> +#define SUN4I_GPADC_CTRL2				0x08
> +
> +#define SUN4I_GPADC_CTRL2_TP_SENSITIVE_ADJUST(x)	((GENMASK(3, 0) & (x)) << 28)
> +#define SUN4I_GPADC_CTRL2_TP_MODE_SELECT(x)		((GENMASK(1, 0) & (x)) << 26)
> +#define SUN4I_GPADC_CTRL2_PRE_MEA_EN			BIT(24)
> +#define SUN4I_GPADC_CTRL2_PRE_MEA_THRE_CNT(x)		(GENMASK(23, 0) & (x))
> +
> +#define SUN4I_GPADC_CTRL3				0x0c
> +
> +#define SUN4I_GPADC_CTRL3_FILTER_EN			BIT(2)
> +#define SUN4I_GPADC_CTRL3_FILTER_TYPE(x)		(GENMASK(1, 0) & (x))
> +
> +#define SUN4I_GPADC_TPR					0x18
> +
> +#define SUN4I_GPADC_TPR_TEMP_ENABLE			BIT(16)
> +#define SUN4I_GPADC_TPR_TEMP_PERIOD(x)			(GENMASK(15, 0) & (x))
> +
> +#define SUN4I_GPADC_INT_FIFOC				0x10
> +
> +#define SUN4I_GPADC_INT_FIFOC_TEMP_IRQ_EN		BIT(18)
> +#define SUN4I_GPADC_INT_FIFOC_TP_OVERRUN_IRQ_EN		BIT(17)
> +#define SUN4I_GPADC_INT_FIFOC_TP_DATA_IRQ_EN		BIT(16)
> +#define SUN4I_GPADC_INT_FIFOC_TP_DATA_XY_CHANGE		BIT(13)
> +#define SUN4I_GPADC_INT_FIFOC_TP_FIFO_TRIG_LEVEL(x)	((GENMASK(4, 0) & (x)) << 8)
> +#define SUN4I_GPADC_INT_FIFOC_TP_DATA_DRQ_EN		BIT(7)
> +#define SUN4I_GPADC_INT_FIFOC_TP_FIFO_FLUSH		BIT(4)
> +#define SUN4I_GPADC_INT_FIFOC_TP_UP_IRQ_EN		BIT(1)
> +#define SUN4I_GPADC_INT_FIFOC_TP_DOWN_IRQ_EN		BIT(0)
> +
> +#define SUN4I_GPADC_INT_FIFOS				0x14
> +
> +#define SUN4I_GPADC_INT_FIFOS_TEMP_DATA_PENDING		BIT(18)
> +#define SUN4I_GPADC_INT_FIFOS_FIFO_OVERRUN_PENDING	BIT(17)
> +#define SUN4I_GPADC_INT_FIFOS_FIFO_DATA_PENDING		BIT(16)
> +#define SUN4I_GPADC_INT_FIFOS_TP_IDLE_FLG		BIT(2)
> +#define SUN4I_GPADC_INT_FIFOS_TP_UP_PENDING		BIT(1)
> +#define SUN4I_GPADC_INT_FIFOS_TP_DOWN_PENDING		BIT(0)
> +
> +#define SUN4I_GPADC_CDAT				0x1c
> +#define SUN4I_GPADC_TEMP_DATA				0x20
> +#define SUN4I_GPADC_DATA				0x24
> +
> +#define SUN4I_GPADC_IRQ_FIFO_DATA			0
> +#define SUN4I_GPADC_IRQ_TEMP_DATA			1
> +
> +/* 10s delay before suspending the IP */
> +#define SUN4I_GPADC_AUTOSUSPEND_DELAY			10000
> +
> +struct sun4i_gpadc_mfd_dev {
> +	struct device			*dev;
> +	struct regmap			*regmap;
> +	struct regmap_irq_chip_data	*regmap_irqc;
> +	void __iomem			*regs;

It's *much* more common to call this 'base'.

> +};
> +
> +#endif

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