Re: [PATCH v3 2/4] mfd: add support for Allwinner SoCs ADC

[Maxime Ripard <maxime.ripard@free-electrons.com>]

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Hi Quentin,

On Tue, Jul 26, 2016 at 09:43:45AM +0200, 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@free-electrons.com>
> ---
> 
> 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/sunxi-gpadc-mfd.c       | 189 ++++++++++++++++++++++++++++++++++++
>  include/linux/mfd/sunxi-gpadc-mfd.h |  94 ++++++++++++++++++

Renaming the driver would be nice too.

>  4 files changed, 300 insertions(+)
>  create mode 100644 drivers/mfd/sunxi-gpadc-mfd.c
>  create mode 100644 include/linux/mfd/sunxi-gpadc-mfd.h
> 
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 1bcf601..6180c2d 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
> +	  sunxi-gpadc-iio and the hwmon driver iio_hwmon.
> +
> +	  To compile this driver as a module, choose M here: the module will be
> +	  called sunxi-gpadc-mfd.
> +
>  config MFD_AS3711
>  	bool "AMS AS3711"
>  	select MFD_CORE
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 42a66e1..9dfd033 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)	+= sunxi-gpadc-mfd.o
> diff --git a/drivers/mfd/sunxi-gpadc-mfd.c b/drivers/mfd/sunxi-gpadc-mfd.c
> new file mode 100644
> index 0000000..3d70af0
> --- /dev/null
> +++ b/drivers/mfd/sunxi-gpadc-mfd.c
> @@ -0,0 +1,189 @@
> +/* ADC MFD core driver for sunxi platforms
> + *
> + * Copyright (c) 2016 Quentin Schulz <quentin.schulz@free-electrons>
> + *
> + * 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/sunxi-gpadc-mfd.h>
> +
> +static struct resource adc_resources[] = {
> +	{
> +		.name	= "FIFO_DATA_PENDING",
> +		.start	= SUNXI_IRQ_FIFO_DATA,
> +		.end	= SUNXI_IRQ_FIFO_DATA,
> +		.flags	= IORESOURCE_IRQ,
> +	}, {
> +		.name	= "TEMP_DATA_PENDING",
> +		.start	= SUNXI_IRQ_TEMP_DATA,
> +		.end	= SUNXI_IRQ_TEMP_DATA,
> +		.flags	= IORESOURCE_IRQ,
> +	},
> +};
> +
> +static const struct regmap_irq sunxi_gpadc_mfd_regmap_irq[] = {
> +	REGMAP_IRQ_REG(SUNXI_IRQ_FIFO_DATA, 0,
> +		       SUNXI_GPADC_TP_INT_FIFOC_TP_DATA_IRQ_EN),
> +	REGMAP_IRQ_REG(SUNXI_IRQ_TEMP_DATA, 0,
> +		       SUNXI_GPADC_TP_INT_FIFOC_TEMP_IRQ_EN),
> +};
> +
> +static const struct regmap_irq_chip sunxi_gpadc_mfd_regmap_irq_chip = {
> +	.name = "sunxi_gpadc_mfd_irq_chip",
> +	.status_base = SUNXI_GPADC_TP_INT_FIFOS,
> +	.ack_base = SUNXI_GPADC_TP_INT_FIFOS,
> +	.mask_base = SUNXI_GPADC_TP_INT_FIFOC,
> +	.init_ack_masked = true,
> +	.mask_invert = true,
> +	.irqs = sunxi_gpadc_mfd_regmap_irq,
> +	.num_irqs = ARRAY_SIZE(sunxi_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",
> +	}
> +};
> +
> +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",
> +	},
> +};
> +
> +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",
> +	},
> +};
> +
> +static const struct regmap_config sunxi_gpadc_mfd_regmap_config = {
> +	.reg_bits = 32,
> +	.val_bits = 32,
> +	.reg_stride = 4,
> +	.fast_io = true,
> +};
> +
> +static const struct of_device_id sunxi_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 */ }
> +};
> +
> +static int sunxi_gpadc_mfd_probe(struct platform_device *pdev)
> +{
> +	struct sunxi_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(sunxi_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,
> +						&sunxi_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, SUNXI_GPADC_TP_INT_FIFOC, 0);
> +
> +	irq = platform_get_irq(pdev, 0);
> +	ret = regmap_add_irq_chip(mfd_dev->regmap, irq, IRQF_ONESHOT, 0,
> +				  &sunxi_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 = 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);
> +		goto err;
> +	}
> +
> +	return 0;
> +err:
> +	regmap_del_irq_chip(irq, mfd_dev->regmap_irqc);
> +	return ret;
> +}
> +
> +static int sunxi_gpadc_mfd_remove(struct platform_device *pdev)
> +{
> +	struct sunxi_gpadc_mfd_dev *mfd_dev;
> +	unsigned int irq;
> +
> +	irq = platform_get_irq(pdev, 0);

You can store the irq number instead of looking it up twice.

> +	mfd_remove_devices(&pdev->dev);
> +	mfd_dev = dev_get_drvdata(&pdev->dev);
> +	regmap_del_irq_chip(irq, mfd_dev->regmap_irqc);
> +
> +	return 0;
> +}
> +
> +MODULE_DEVICE_TABLE(of, sunxi_gpadc_mfd_of_match);
> +
> +static struct platform_driver sunxi_gpadc_mfd_driver = {
> +	.driver = {
> +		.name = "sunxi-adc-mfd",
> +		.of_match_table = of_match_ptr(sunxi_gpadc_mfd_of_match),
> +	},
> +	.probe = sunxi_gpadc_mfd_probe,
> +	.remove = sunxi_gpadc_mfd_remove,
> +};
> +
> +module_platform_driver(sunxi_gpadc_mfd_driver);
> +
> +MODULE_DESCRIPTION("Allwinner sunxi platforms' GPADC MFD core driver");
> +MODULE_AUTHOR("Quentin Schulz <quentin.schulz@free-electrons.com>");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/mfd/sunxi-gpadc-mfd.h b/include/linux/mfd/sunxi-gpadc-mfd.h
> new file mode 100644
> index 0000000..c21abae
> --- /dev/null
> +++ b/include/linux/mfd/sunxi-gpadc-mfd.h
> @@ -0,0 +1,94 @@
> +/* Header of ADC MFD core driver for sunxi platforms
> + *
> + * Copyright (c) 2016 Quentin Schulz <quentin.schulz@free-electrons>
> + *
> + * 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 __SUNXI_GPADC_MFD__H__
> +#define __SUNXI_GPADC_MFD__H__
> +
> +#define SUNXI_GPADC_TP_CTRL0				0x00
> +
> +#define SUNXI_GPADC_TP_CTRL0_ADC_FIRST_DLY(x)		((GENMASK(7, 0) & (x)) << 24)
> +#define SUNXI_GPADC_TP_CTRL0_ADC_FIRST_DLY_MODE		BIT(23)
> +#define SUNXI_GPADC_TP_CTRL0_ADC_CLK_SELECT		BIT(22)
> +#define SUNXI_GPADC_TP_CTRL0_ADC_CLK_DIVIDER(x)		((GENMASK(1, 0) & (x)) << 20)
> +#define SUNXI_GPADC_TP_CTRL0_FS_DIV(x)			((GENMASK(3, 0) & (x)) << 16)
> +#define SUNXI_GPADC_TP_CTRL0_T_ACQ(x)			(GENMASK(15, 0) & (x))
> +
> +#define SUNXI_GPADC_TP_CTRL1				0x04

Isn't GPADC and TP redundant in your prefix, you seem to be always
using TP, even for non touchscreen related defines...

> +
> +#define SUNXI_GPADC_TP_CTRL1_STYLUS_UP_DEBOUNCE(x)	((GENMASK(7, 0) & (x)) << 12)
> +#define SUNXI_GPADC_TP_CTRL1_STYLUS_UP_DEBOUNCE_EN	BIT(9)
> +#define SUNXI_GPADC_TP_CTRL1_TOUCH_PAN_CALI_EN		BIT(6)
> +#define SUNXI_GPADC_TP_CTRL1_TP_DUAL_EN			BIT(5)
> +#define SUNXI_GPADC_TP_CTRL1_TP_MODE_EN			BIT(4)
> +#define SUNXI_GPADC_TP_CTRL1_TP_ADC_SELECT		BIT(3)

... sometimes twice ...

> +#define SUNXI_GPADC_TP_CTRL1_ADC_CHAN_SELECT(x)		(GENMASK(2, 0) & (x))
> +
> +/* TP_CTRL1 bits for sun6i SOCs */
> +#define SUNXI_GPADC_TP_CTRL1_SUN6I_TOUCH_PAN_CALI_EN	BIT(7)
> +#define SUNXI_GPADC_TP_CTRL1_SUN6I_TP_DUAL_EN		BIT(6)
> +#define SUNXI_GPADC_TP_CTRL1_SUN6I_TP_MODE_EN		BIT(5)
> +#define SUNXI_GPADC_TP_CTRL1_SUN6I_TP_ADC_SELECT	BIT(4)
> +#define SUNXI_GPADC_TP_CTRL1_SUN6I_ADC_CHAN_SELECT(x)	(GENMASK(3, 0) & BIT(x))
> +
> +#define SUNXI_GPADC_TP_CTRL2				0x08
> +
> +#define SUNXI_GPADC_TP_CTRL2_TP_SENSITIVE_ADJUST(x)	((GENMASK(3, 0) & (x)) << 28)
> +#define SUNXI_GPADC_TP_CTRL2_TP_MODE_SELECT(x)		((GENMASK(1, 0) & (x)) << 26)
> +#define SUNXI_GPADC_TP_CTRL2_PRE_MEA_EN			BIT(24)
> +#define SUNXI_GPADC_TP_CTRL2_PRE_MEA_THRE_CNT(x)	(GENMASK(23, 0) & (x))
> +
> +#define SUNXI_GPADC_TP_CTRL3				0x0c
> +
> +#define SUNXI_GPADC_TP_CTRL3_FILTER_EN			BIT(2)
> +#define SUNXI_GPADC_TP_CTRL3_FILTER_TYPE(x)		(GENMASK(1, 0) & (x))
> +
> +#define SUNXI_GPADC_TP_TPR				0x18
> +
> +#define SUNXI_GPADC_TP_TPR_TEMP_ENABLE			BIT(16)
> +#define SUNXI_GPADC_TP_TPR_TEMP_PERIOD(x)		(GENMASK(15, 0) & (x))
> +
> +#define SUNXI_GPADC_TP_INT_FIFOC			0x10
> +
> +#define SUNXI_GPADC_TP_INT_FIFOC_TEMP_IRQ_EN		BIT(18)
> +#define SUNXI_GPADC_TP_INT_FIFOC_TP_OVERRUN_IRQ_EN	BIT(17)
> +#define SUNXI_GPADC_TP_INT_FIFOC_TP_DATA_IRQ_EN		BIT(16)
> +#define SUNXI_GPADC_TP_INT_FIFOC_TP_DATA_XY_CHANGE	BIT(13)
> +#define SUNXI_GPADC_TP_INT_FIFOC_TP_FIFO_TRIG_LEVEL(x)	((GENMASK(4, 0) & (x)) << 8)
> +#define SUNXI_GPADC_TP_INT_FIFOC_TP_DATA_DRQ_EN		BIT(7)
> +#define SUNXI_GPADC_TP_INT_FIFOC_TP_FIFO_FLUSH		BIT(4)
> +#define SUNXI_GPADC_TP_INT_FIFOC_TP_UP_IRQ_EN		BIT(1)
> +#define SUNXI_GPADC_TP_INT_FIFOC_TP_DOWN_IRQ_EN		BIT(0)
> +
> +#define SUNXI_GPADC_TP_INT_FIFOS			0x14
> +
> +#define SUNXI_GPADC_TP_INT_FIFOS_TEMP_DATA_PENDING	BIT(18)
> +#define SUNXI_GPADC_TP_INT_FIFOS_FIFO_OVERRUN_PENDING	BIT(17)
> +#define SUNXI_GPADC_TP_INT_FIFOS_FIFO_DATA_PENDING	BIT(16)
> +#define SUNXI_GPADC_TP_INT_FIFOS_TP_IDLE_FLG		BIT(2)
> +#define SUNXI_GPADC_TP_INT_FIFOS_TP_UP_PENDING		BIT(1)
> +#define SUNXI_GPADC_TP_INT_FIFOS_TP_DOWN_PENDING	BIT(0)
> +
> +#define SUNXI_GPADC_TP_CDAT				0x1c
> +#define SUNXI_GPADC_TEMP_DATA				0x20
> +#define SUNXI_GPADC_TP_DATA				0x24
> +
> +#define SUNXI_IRQ_FIFO_DATA				0
> +#define SUNXI_IRQ_TEMP_DATA				1

... and sometimes not at all.

> +
> +/* 10s delay before suspending the IP */
> +#define SUNXI_GPADC_AUTOSUSPEND_DELAY			10000
> +
> +struct sunxi_gpadc_mfd_dev {
> +	struct device			*dev;
> +	struct regmap			*regmap;
> +	struct regmap_irq_chip_data	*regmap_irqc;
> +	void __iomem			*regs;
> +};
> +
> +#endif
> -- 
> 2.5.0
> 

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

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