Subject: [PATCH v2 1/6] mfd: fsl imx25 Touchscreen ADC driver

From: [email-masked] (Jonathan Cameron)
Date: Sat, 21 Jun 2014 11:09:22 +0100

On 13/06/14 16:21, Denis Carikli wrote:
> From: Markus Pargmann <[email-masked]>
>
> This is the core driver for imx25 touchscreen/adc driver. The module
> has one shared ADC and two different conversion queues which use the
> ADC. The two queues are identical. Both can be used for general purpose
> ADC but one is meant to be used for touchscreens.
>
> This driver is the core which manages the central components and
> registers of the TSC/ADC unit. It manages the IRQs and forwards them to
> the correct components.
>
> Signed-off-by: Markus Pargmann <[email-masked]>
> Signed-off-by: Denis Carikli <[email-masked]>
Hi,

A couple of trivial bits inline.  Otherwise,
Acked-by: Jonathan Cameron <[email-masked]>

Note I have not dived into the datasheet for this review
(hence not a reviewed by!)  Too many other things to do today!
> ---
>   .../devicetree/bindings/mfd/fsl-imx25-tsadc.txt    |   46 ++++
>   drivers/mfd/Kconfig                                |    9 +
>   drivers/mfd/Makefile                               |    2 +
>   drivers/mfd/fsl-imx25-tsadc.c                      |  232 ++++++++++++++++++++
>   include/linux/mfd/imx25-tsadc.h                    |  138 ++++++++++++
>   5 files changed, 427 insertions(+)
>   create mode 100644 Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt
>   create mode 100644 drivers/mfd/fsl-imx25-tsadc.c
>   create mode 100644 include/linux/mfd/imx25-tsadc.h
>
> diff --git a/Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt b/Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt
> new file mode 100644
> index 0000000..a857af0e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mfd/fsl-imx25-tsadc.txt
> @@ -0,0 +1,46 @@
> +Freescale mx25 ADC/TSC multifunction device
> +
> +This device combines two general purpose conversion queues one used for general
> +ADC and the other used for touchscreens.
> +
> +Required properties:
> + - compatible: Should be "fsl,imx25-tsadc".
> + - reg: Memory range of the device.
> + - interrupts: Interrupt for this device as described in
> +   interrupts/interrupts.txt
> + - clocks: An 'ipg' clock defined as described in clocks/clock.txt
> + - interrupt-controller: This device is an interrupt controller. It controls
> +   the interrupts of both conversion queues.
> + - #interrupt-cells: Should be '<1>'.
> + - #address-cells: Should be '<1>'.
> + - #size-cells: Should be '<1>'.
> + - ranges
> +
> +This device includes two conversion queues which can be added as subnodes.
> +The first queue is for the touchscreen, the second for general purpose ADC.
> +
> +Example:
> +	tscadc: tscadc at 50030000 {
> +		compatible = "fsl,imx25-tsadc";
> +		reg = <0x50030000 0xc>;
> +		interrupts = <46>;
> +		clocks = <&clks 119>;
> +		clock-names = "ipg";
> +		interrupt-controller;
> +		#interrupt-cells = <1>;
> +		#address-cells = <1>;
> +		#size-cells = <1>;
> +		ranges;
> +
> +		tsc: tcq at 50030400 {
> +			compatible = "fsl,imx25-tcq";
> +			reg = <0x50030400 0x60>;
> +			...
> +		};
> +
> +		adc: gcq at 50030800 {
> +			compatible = "fsl,imx25-gcq";
> +			reg = <0x50030800 0x60>;
> +			...
> +		};
> +	};
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index ee8204c..73f4e66 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -183,6 +183,15 @@ config MFD_DA9063
>   	  Additional drivers must be enabled in order to use the functionality
>   	  of the device.
>
> +config MFD_MX25_TSADC
> +	tristate "Freescale i.MX25 integrated Touchscreen and ADC unit"
> +	depends on ARCH_MXC
> +	select REGMAP_MMIO
> +	help
> +	  Enable support for the integrated Touchscreen and ADC unit of the
> +	  i.MX25 processors. They consist of a conversion queue for general
> +	  purpose ADC and a queue for Touchscreens.
> +
>   config MFD_MC13XXX
>   	tristate
>   	depends on (SPI_MASTER || I2C)
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 8afedba..7ff1013 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -78,6 +78,8 @@ obj-$(CONFIG_TWL4030_POWER)    += twl4030-power.o
>   obj-$(CONFIG_MFD_TWL4030_AUDIO)	+= twl4030-audio.o
>   obj-$(CONFIG_TWL6040_CORE)	+= twl6040.o
>
> +obj-$(CONFIG_MFD_MX25_TSADC)	+= fsl-imx25-tsadc.o
> +
>   obj-$(CONFIG_MFD_MC13XXX)	+= mc13xxx-core.o
>   obj-$(CONFIG_MFD_MC13XXX_SPI)	+= mc13xxx-spi.o
>   obj-$(CONFIG_MFD_MC13XXX_I2C)	+= mc13xxx-i2c.o
> diff --git a/drivers/mfd/fsl-imx25-tsadc.c b/drivers/mfd/fsl-imx25-tsadc.c
> new file mode 100644
> index 0000000..10332c2
> --- /dev/null
> +++ b/drivers/mfd/fsl-imx25-tsadc.c
> @@ -0,0 +1,232 @@
> +/*
> + * Copyright 2014 Markus Pargmann, Pengutronix <[email-masked]>
> + *
> + * The code contained herein is licensed under the GNU General Public
> + * License. You may obtain a copy of the GNU General Public License
> + * Version 2 or later at the following locations:
> + *
> + * http://www.opensource.org/licenses/gpl-license.html
> + * http://www.gnu.org/copyleft/gpl.html
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/irqdesc.h>
> +#include <linux/irqdomain.h>
> +#include <linux/irqchip/chained_irq.h>
> +#include <linux/mfd/imx25-tsadc.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +struct mx25_tsadc_priv {
> +	struct regmap *regs;
> +	struct irq_domain *domain;
> +	struct clk *clk;
> +};
> +
> +static struct regmap_config mx25_tsadc = {
> +	.fast_io = true,
> +	.max_register = 0x8,
> +	.reg_bits = 32,
> +	.val_bits = 32,
> +	.reg_stride = 4,
> +};
> +
> +struct regmap *mx25_tsadc_get_regmap(struct device *dev)
> +{
> +	struct platform_device *pdev;
> +	struct mx25_tsadc_priv *priv;
> +
> +	if (!dev)
> +		return NULL;
> +
> +	pdev = container_of(dev, struct platform_device, dev);
> +	priv = platform_get_drvdata(pdev);
> +	if (IS_ERR_OR_NULL(priv->regs))
> +		return NULL;
> +
> +	return priv->regs;
> +}
> +EXPORT_SYMBOL(mx25_tsadc_get_regmap);
> +
> +struct clk *mx25_tsadc_get_ipg(struct device *dev)
> +{
> +	struct platform_device *pdev;
> +	struct mx25_tsadc_priv *priv;
> +
> +	if (!dev)
> +		return NULL;
> +
> +	pdev = container_of(dev, struct platform_device, dev);
> +	priv = platform_get_drvdata(pdev);
> +	if (IS_ERR_OR_NULL(priv->clk))
> +		return NULL;
> +
> +	return priv->clk;
> +}
> +EXPORT_SYMBOL(mx25_tsadc_get_ipg);
> +
> +static void mx25_tsadc_irq_handler(u32 irq, struct irq_desc *desc)
> +{
> +	struct mx25_tsadc_priv *priv = irq_desc_get_handler_data(desc);
> +	struct irq_chip *chip = irq_get_chip(irq);
> +	u32 status;
> +
> +	chained_irq_enter(chip, desc);
> +
> +	regmap_read(priv->regs, MX25_TSC_TGSR, &status);
> +
> +	if (status & MX25_TGSR_GCQ_INT)
> +		generic_handle_irq(irq_find_mapping(priv->domain, 1));
> +
> +	if (status & MX25_TGSR_TCQ_INT)
> +		generic_handle_irq(irq_find_mapping(priv->domain, 0));
> +
> +	chained_irq_exit(chip, desc);
> +}
> +
> +static void mx25_tsadc_nop(struct irq_data *d)
> +{
> +}
> +
> +static int mx25_tsadc_set_wake_nop(struct irq_data *d, unsigned int state)
> +{
> +	return 0;
> +}
> +
> +static struct irq_chip mx25_tsadc_irq_chip = {
> +	.name = "mx25-tsadc",
> +	.irq_ack = mx25_tsadc_nop,
> +	.irq_mask = mx25_tsadc_nop,
> +	.irq_unmask = mx25_tsadc_nop,
> +	.irq_set_wake = mx25_tsadc_set_wake_nop,
Whilst this is not documented as being optional, in kernel/irq/manage.c it
clearly is.  Otherwise, what you appear to have here is the same (up to
a name) as the dummy_irq_chip provided for just such dumb devices. Could
you use that?
> +};
> +
> +static int mx25_tsadc_domain_map(struct irq_domain *d, unsigned int irq,
> +			     irq_hw_number_t hwirq)
> +{
> +	struct mx25_tsadc_priv *priv = d->host_data;
> +
> +	irq_set_chip_data(irq, priv);
> +	irq_set_chip_and_handler(irq, &mx25_tsadc_irq_chip,
> +				 handle_level_irq);
> +
> +
Bonus blank line here.
> +	set_irq_flags(irq, IRQF_VALID);
> +
> +	return 0;
> +}
> +
> +static struct irq_domain_ops mx25_tsadc_domain_ops = {
> +	.map = mx25_tsadc_domain_map,
> +	.xlate = irq_domain_xlate_onecell,
> +};
> +
> +static int mx25_tsadc_setup_irq(struct platform_device *pdev,
> +		struct mx25_tsadc_priv *priv)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	int irq;
> +
> +	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0) {
> +		dev_err(dev, "Failed to get irq\n");
> +		return irq;
> +	}
> +
> +	priv->domain = irq_domain_add_simple(np, 2, 0, &mx25_tsadc_domain_ops,
> +			priv);
> +	if (!priv->domain) {
> +		dev_err(dev, "Failed to add irq domain\n");
> +		return -ENOMEM;
> +	}
> +
> +	irq_set_chained_handler(irq, mx25_tsadc_irq_handler);
> +	irq_set_handler_data(irq, priv);
> +
> +	return 0;
> +}
> +
> +static int mx25_tsadc_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct mx25_tsadc_priv *priv;
> +	struct resource *iores;
> +	int ret;
> +	void __iomem *iomem;
> +
> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
Worth checking whether this succeeded (!=NULL)?
> +	iomem = devm_ioremap_resource(dev, iores);
> +	if (IS_ERR(iomem)) {
> +		dev_err(dev, "Failed to remap iomem\n");
> +		return PTR_ERR(iomem);
> +	}
> +
> +	priv->regs = regmap_init_mmio(dev, iomem, &mx25_tsadc);
> +	if (IS_ERR(priv->regs)) {
> +		dev_err(dev, "Failed to initialize regmap\n");
> +		return PTR_ERR(priv->regs);
> +	}
> +
> +	priv->clk = devm_clk_get(dev, "ipg");
> +	if (IS_ERR(priv->clk)) {
> +		dev_err(dev, "Failed to get ipg clock\n");
> +		return PTR_ERR(priv->clk);
> +	}
> +
> +	/* Enable clock and reset the component */
> +	regmap_update_bits(priv->regs, MX25_TSC_TGCR, MX25_TGCR_CLK_EN,
> +			MX25_TGCR_CLK_EN);
> +	regmap_update_bits(priv->regs, MX25_TSC_TGCR, MX25_TGCR_TSC_RST,
> +			MX25_TGCR_TSC_RST);
> +
> +	/* Setup powersaving mode, but enable internal reference voltage */
> +	regmap_update_bits(priv->regs, MX25_TSC_TGCR, MX25_TGCR_POWERMODE_MASK,
> +			MX25_TGCR_POWERMODE_SAVE);
> +	regmap_update_bits(priv->regs, MX25_TSC_TGCR, MX25_TGCR_INTREFEN,
> +			MX25_TGCR_INTREFEN);
> +
> +	ret = mx25_tsadc_setup_irq(pdev, priv);
> +	if (ret) {
> +		dev_err(dev, "Failed to setup irqs\n");
> +		return ret;
> +	}
> +
> +	platform_set_drvdata(pdev, priv);
> +
> +	of_platform_populate(np, NULL, NULL, dev);
> +
> +	dev_info(dev, "i.MX25 Touchscreen and ADC core driver loaded\n");
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id mx25_tsadc_ids[] = {
> +	{ .compatible = "fsl,imx25-tsadc", },
> +	{ /* Sentinel */ }
> +};
> +
> +static struct platform_driver mx25_tsadc_driver = {
> +	.driver		= {
> +		.name	= "mx25-tsadc",
> +		.owner	= THIS_MODULE,
> +		.of_match_table = mx25_tsadc_ids,
> +	},
> +	.probe		= mx25_tsadc_probe,
> +};
> +module_platform_driver(mx25_tsadc_driver);
> +
> +MODULE_DESCRIPTION("MFD for ADC/TSC for Freescale mx25");
> +MODULE_AUTHOR("Markus Pargmann <[email-masked]>");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:mx25-tsadc");
> diff --git a/include/linux/mfd/imx25-tsadc.h b/include/linux/mfd/imx25-tsadc.h
> new file mode 100644
> index 0000000..6fba341
> --- /dev/null
> +++ b/include/linux/mfd/imx25-tsadc.h
> @@ -0,0 +1,138 @@
> +#ifndef _LINUX_INCLUDE_INPUT_IMX25_TSADC_H_
> +#define _LINUX_INCLUDE_INPUT_IMX25_TSADC_H_
> +
> +struct regmap;
> +struct device;
> +struct clk;
> +
> +struct regmap *mx25_tsadc_get_regmap(struct device *dev);
> +struct clk *mx25_tsadc_get_ipg(struct device *dev);
> +
> +#define MX25_TSC_TGCR 0x00
> +#define MX25_TSC_TGSR 0x04
> +#define MX25_TSC_TICR 0x08
> +
> +/* The same register layout for TC and GC queue */
> +#define MX25_ADCQ_FIFO 0x00
> +#define MX25_ADCQ_CR 0x04
> +#define MX25_ADCQ_SR 0x08
> +#define MX25_ADCQ_MR 0x0c
> +#define MX25_ADCQ_ITEM_7_0 0x20
> +#define MX25_ADCQ_ITEM_15_8 0x24
> +#define MX25_ADCQ_CFG(n) (0x40 + ((n) * 0x4))
> +
> +/* Register values */
> +/* Queue Config register */
> +#define MX25_ADCQ_MR_MASK 0xffffffff
> +
> +/* TGCR */
> +#define MX25_TGCR_PDBTIME(x) ((x) << 25)
> +#define MX25_TGCR_PDBTIME_MASK MX25_TGCR_PDBTIME(0x7f)
> +#define MX25_TGCR_PDBEN (1 << 24)
> +#define MX25_TGCR_PDEN (1 << 23)
> +#define MX25_TGCR_ADCCLKCFG(x) ((x) << 16)
> +#define MX25_TGCR_GET_ADCCLK(x) (((x) >> 16) & 0x1f)
> +#define MX25_TGCR_INTREFEN (1 << 10)
> +#define MX25_TGCR_POWERMODE_MASK (3 << 8)
> +#define MX25_TGCR_POWERMODE_SAVE (1 << 8)
> +#define MX25_TGCR_POWERMODE_ON (2 << 8)
> +#define MX25_TGCR_STLC (1 << 5)
> +#define MX25_TGCR_SLPC (1 << 4)
> +#define MX25_TGCR_FUNC_RST (1 << 2)
> +#define MX25_TGCR_TSC_RST (1 << 1)
> +#define MX25_TGCR_CLK_EN (1 << 0)
> +
> +/* TGSR */
> +#define MX25_TGSR_SLP_INT (1 << 2)
> +#define MX25_TGSR_GCQ_INT (1 << 1)
> +#define MX25_TGSR_TCQ_INT (1 << 0)
> +
> +/* ADCQ_ITEM_* */
> +#define _MX25_ADCQ_ITEM(item, x) ((x) << ((item) * 4))
> +#define MX25_ADCQ_ITEM(item, x) ((item) >= 8 ? \
> +		_MX25_ADCQ_ITEM((item) - 8, (x)) : _MX25_ADCQ_ITEM((item), (x)))
> +
> +/* ADCQ_FIFO (TCQFIFO and GCQFIFO) */
> +#define MX25_ADCQ_FIFO_DATA(x) (((x) >> 4) & 0xfff)
> +#define MX25_ADCQ_FIFO_ID(x) ((x) & 0xf)
> +
> +/* ADCQ_CR (TCQR and GCQR) */
> +#define MX25_ADCQ_CR_PDCFG_LEVEL (1 << 19)
> +#define MX25_ADCQ_CR_PDMSK (1 << 18)
> +#define MX25_ADCQ_CR_FRST (1 << 17)
> +#define MX25_ADCQ_CR_QRST (1 << 16)
> +#define MX25_ADCQ_CR_RWAIT_MASK (0xf << 12)
> +#define MX25_ADCQ_CR_RWAIT(x) ((x) << 12)
> +#define MX25_ADCQ_CR_WMRK_MASK (0xf << 8)
> +#define MX25_ADCQ_CR_WMRK(x) ((x) << 8)
> +#define MX25_ADCQ_CR_LITEMID_MASK (0xf << 4)
> +#define MX25_ADCQ_CR_LITEMID(x) ((x) << 4)
> +#define MX25_ADCQ_CR_RPT (1 << 3)
> +#define MX25_ADCQ_CR_FQS (1 << 2)
> +#define MX25_ADCQ_CR_QSM_MASK 0x3
> +#define MX25_ADCQ_CR_QSM_PD 0x1
> +#define MX25_ADCQ_CR_QSM_FQS 0x2
> +#define MX25_ADCQ_CR_QSM_FQS_PD 0x3
> +
> +/* ADCQ_SR (TCQSR and GCQSR) */
> +#define MX25_ADCQ_SR_FDRY (1 << 15)
> +#define MX25_ADCQ_SR_FULL (1 << 14)
> +#define MX25_ADCQ_SR_EMPT (1 << 13)
> +#define MX25_ADCQ_SR_FDN(x) (((x) >> 8) & 0x1f)
> +#define MX25_ADCQ_SR_FRR (1 << 6)
> +#define MX25_ADCQ_SR_FUR (1 << 5)
> +#define MX25_ADCQ_SR_FOR (1 << 4)
> +#define MX25_ADCQ_SR_EOQ (1 << 1)
> +#define MX25_ADCQ_SR_PD (1 << 0)
> +
> +/* ADCQ_MR (TCQMR and GCQMR) */
> +#define MX25_ADCQ_MR_FDRY_DMA (1 << 31)
> +#define MX25_ADCQ_MR_FER_DMA (1 << 22)
> +#define MX25_ADCQ_MR_FUR_DMA (1 << 21)
> +#define MX25_ADCQ_MR_FOR_DMA (1 << 20)
> +#define MX25_ADCQ_MR_EOQ_DMA (1 << 17)
> +#define MX25_ADCQ_MR_PD_DMA (1 << 16)
> +#define MX25_ADCQ_MR_FDRY_IRQ (1 << 15)
> +#define MX25_ADCQ_MR_FER_IRQ (1 << 6)
> +#define MX25_ADCQ_MR_FUR_IRQ (1 << 5)
> +#define MX25_ADCQ_MR_FOR_IRQ (1 << 4)
> +#define MX25_ADCQ_MR_EOQ_IRQ (1 << 1)
> +#define MX25_ADCQ_MR_PD_IRQ (1 << 0)
> +
> +/* ADCQ_CFG (TICR, TCC0-7,GCC0-7) */
> +#define MX25_ADCQ_CFG_SETTLING_TIME(x) ((x) << 24)
> +#define MX25_ADCQ_CFG_IGS (1 << 20)
> +#define MX25_ADCQ_CFG_NOS_MASK (0xf << 16)
> +#define MX25_ADCQ_CFG_NOS(x) (((x) - 1) << 16)
> +#define MX25_ADCQ_CFG_WIPER (1 << 15)
> +#define MX25_ADCQ_CFG_YNLR (1 << 14)
> +#define MX25_ADCQ_CFG_YPLL_HIGH 0
> +#define MX25_ADCQ_CFG_YPLL_OFF (1 << 12)
> +#define MX25_ADCQ_CFG_YPLL_LOW (3 << 12)
> +#define MX25_ADCQ_CFG_XNUR_HIGH 0
> +#define MX25_ADCQ_CFG_XNUR_OFF (1 << 10)
> +#define MX25_ADCQ_CFG_XNUR_LOW (3 << 10)
> +#define MX25_ADCQ_CFG_XPUL_OFF (1 << 9)
> +#define MX25_ADCQ_CFG_XPUL_HIGH 0
> +#define MX25_ADCQ_CFG_REFP_YP 0
> +#define MX25_ADCQ_CFG_REFP_XP (1 << 7)
> +#define MX25_ADCQ_CFG_REFP_EXT (2 << 7)
> +#define MX25_ADCQ_CFG_REFP_INT (3 << 7)
> +#define MX25_ADCQ_CFG_REFP_MASK (3 << 7)
> +#define MX25_ADCQ_CFG_IN_XP 0
> +#define MX25_ADCQ_CFG_IN_YP (1 << 4)
> +#define MX25_ADCQ_CFG_IN_XN (2 << 4)
> +#define MX25_ADCQ_CFG_IN_YN (3 << 4)
> +#define MX25_ADCQ_CFG_IN_WIPER (4 << 4)
> +#define MX25_ADCQ_CFG_IN_AUX0 (5 << 4)
> +#define MX25_ADCQ_CFG_IN_AUX1 (6 << 4)
> +#define MX25_ADCQ_CFG_IN_AUX2 (7 << 4)
> +#define MX25_ADCQ_CFG_REFN_XN 0
> +#define MX25_ADCQ_CFG_REFN_YN (1 << 2)
> +#define MX25_ADCQ_CFG_REFN_NGND (2 << 2)
> +#define MX25_ADCQ_CFG_REFN_NGND2 (3 << 2)
> +#define MX25_ADCQ_CFG_REFN_MASK (3 << 2)
> +#define MX25_ADCQ_CFG_PENIACK (1 << 1)
> +
> +
> +#endif  /* _LINUX_INCLUDE_INPUT_IMX25_TSADC_H_ */
>