Re: [PATCH v8 4/8] mfd: fsl imx25 Touchscreen ADC driver

Jonathan Cameron
2015-11-21T17:26:04Z

On 21/11/15 17:02, Jonathan Cameron wrote:
> On 16/11/15 12:01, Markus Pargmann wrote:
>> 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 <mpa-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
>> Signed-off-by: Denis Carikli <denis-fO0SIAKYzcbQT0dZR+AlfA@public.gmane.org>
>>
>> [ensure correct ADC clock depending on the IPG clock]
>> Signed-off-by: Juergen Borleis <jbe-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
> Looks good to me - one query on meaning of a comment inline.
>
> Acked-by: Jonathan Cameron <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
>
> I'm taking the view this series wants to go through the MFD tree
> but don't mind if it goes through IIO or input instead
> if there is a good reason to do so.
>
> Jonathan
>> ---
>>
>> Notes:
>> Changes in v7:
>> - Cleanup bit defines in header files to be more readable
>> - Fix irq check to return with an error for irq <= 0
>> - Add COMPILE_TEST in Kconfig file
>>
>> Changes in v5:
>> - Remove ifdef CONFIG_OF as this driver is only for DT usage
>> - Remove module owner
>> - Add Kconfig dependencies ARCH_MX25 and OF
>>
>> @Jonathan Cameron:
>> I left your acked-by on the patch as these were small changes. If it should be
>> removed, please say so. Thanks
>>
>> drivers/mfd/Kconfig | 9 ++
>> drivers/mfd/Makefile | 2 +
>> drivers/mfd/fsl-imx25-tsadc.c | 204 ++++++++++++++++++++++++++++++++++++++++
>> include/linux/mfd/imx25-tsadc.h | 140 +++++++++++++++++++++++++++
>> 4 files changed, 355 insertions(+)
>> create mode 100644 drivers/mfd/fsl-imx25-tsadc.c
>> create mode 100644 include/linux/mfd/imx25-tsadc.h
>>
>> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
>> index 4d92df6ef9fe..4222e202ad2b 100644
>> --- a/drivers/mfd/Kconfig
>> +++ b/drivers/mfd/Kconfig
>> @@ -271,6 +271,15 @@ config MFD_MC13XXX_I2C
>> help
>> Select this if your MC13xxx is connected via an I2C bus.
>>
>> +config MFD_MX25_TSADC
>> + tristate "Freescale i.MX25 integrated Touchscreen and ADC unit"
>> + select REGMAP_MMIO
>> + depends on (SOC_IMX25 && OF) || COMPILE_TEST
>> + 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_HI6421_PMIC
>> tristate "HiSilicon Hi6421 PMU/Codec IC"
>> depends on OF
>> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
>> index a8b76b81b467..5741be88c173 100644
>> --- a/drivers/mfd/Makefile
>> +++ b/drivers/mfd/Makefile
>> @@ -81,6 +81,8 @@ 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 000000000000..e67d5ca81e10
>> --- /dev/null
>> +++ b/drivers/mfd/fsl-imx25-tsadc.c
>> @@ -0,0 +1,204 @@
>> +/*
>> + * Copyright (C) 2014-2015 Pengutronix, Markus Pargmann <mpa-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
>> + *
>> + * 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/clk.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/irqchip/chained_irq.h>
>> +#include <linux/irqdesc.h>
>> +#include <linux/irqdomain.h>
>> +#include <linux/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>
>> +
>> +static struct regmap_config mx25_tsadc_regmap_config = {
>> + .fast_io = true,
>> + .max_register = 8,
>> + .reg_bits = 32,
>> + .val_bits = 32,
>> + .reg_stride = 4,
>> +};
>> +
>> +static void mx25_tsadc_irq_handler(struct irq_desc *desc)
>> +{
>> + struct mx25_tsadc *tsadc = irq_desc_get_handler_data(desc);
>> + struct irq_chip *chip = irq_desc_get_chip(desc);
>> + u32 status;
>> +
>> + chained_irq_enter(chip, desc);
>> +
>> + regmap_read(tsadc->regs, MX25_TSC_TGSR, &status);
>> +
>> + if (status & MX25_TGSR_GCQ_INT)
>> + generic_handle_irq(irq_find_mapping(tsadc->domain, 1));
>> +
>> + if (status & MX25_TGSR_TCQ_INT)
>> + generic_handle_irq(irq_find_mapping(tsadc->domain, 0));
>> +
>> + chained_irq_exit(chip, desc);
>> +}
>> +
>> +static int mx25_tsadc_domain_map(struct irq_domain *d, unsigned int irq,
>> + irq_hw_number_t hwirq)
>> +{
>> + struct mx25_tsadc *tsadc = d->host_data;
>> +
>> + irq_set_chip_data(irq, tsadc);
>> + irq_set_chip_and_handler(irq, &dummy_irq_chip,
>> + handle_level_irq);
>> + irq_modify_status(irq, IRQ_NOREQUEST, IRQ_NOPROBE);
>> +
>> + 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 *tsadc)
>> +{
>> + 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;
>> + }
>> +
>> + tsadc->domain = irq_domain_add_simple(np, 2, 0, &mx25_tsadc_domain_ops,
>> + tsadc);
>> + if (!tsadc->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, tsadc);
>> +
>> + return 0;
>> +}
>> +
>> +static void mx25_tsadc_setup_clk(struct platform_device *pdev,
>> + struct mx25_tsadc *tsadc)
>> +{
>> + unsigned clk_div;
>> +
>> + /*
>> + * According to the datasheet the ADC clock should never
>> + * exceed 1,75 MHz. Base clock is the IPG and the ADC unit uses
>> + * a funny clock divider. To keep the time constant the ADC needs to do
>> + * one conversion, adapt the ADC internal clock divider to
>> + * the available IPG
> I'm not entirely following this explanation...
> maybe
>
> ...one conversion, then adapt the ADC...
>
>> + */
>> +
>> + dev_dbg(&pdev->dev, "Found master clock at %lu Hz\n",
>> + clk_get_rate(tsadc->clk));
>> +
>> + clk_div = DIV_ROUND_UP(clk_get_rate(tsadc->clk), 1750000);
>> + dev_dbg(&pdev->dev, "Setting up ADC clock divider to %u\n", clk_div);
>> +
>> + /* adc clock = IPG clock / (2 * div + 2) */
>> + clk_div -= 2;
>> + clk_div /= 2;
>> +
>> + /*
>> + * the ADC clock divider changes its behaviour when values below 4
>> + * are used: it is fixed to "/ 10" in this case
>> + */
>> + clk_div = max_t(unsigned, 4, clk_div);
>> +
>> + dev_dbg(&pdev->dev, "Resulting ADC conversion clock at %lu Hz\n",
>> + clk_get_rate(tsadc->clk) / (2 * clk_div + 2));
>> +
>> + regmap_update_bits(tsadc->regs, MX25_TSC_TGCR,
>> + MX25_TGCR_ADCCLKCFG(0x1f),
>> + MX25_TGCR_ADCCLKCFG(clk_div));
>> +}
>> +
>> +static int mx25_tsadc_probe(struct platform_device *pdev)
>> +{
>> + struct device *dev = &pdev->dev;
>> + struct device_node *np = dev->of_node;
>> + struct mx25_tsadc *tsadc;
>> + struct resource *res;
>> + int ret;
>> + void __iomem *iomem;
>> +
>> + tsadc = devm_kzalloc(dev, sizeof(*tsadc), GFP_KERNEL);
>> + if (!tsadc)
>> + return -ENOMEM;
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + iomem = devm_ioremap_resource(dev, res);
>> + if (IS_ERR(iomem))
>> + return PTR_ERR(iomem);
>> +
>> + tsadc->regs = devm_regmap_init_mmio(dev, iomem,
>> + &mx25_tsadc_regmap_config);
>> + if (IS_ERR(tsadc->regs)) {
>> + dev_err(dev, "Failed to initialize regmap\n");
>> + return PTR_ERR(tsadc->regs);
>> + }
>> +
>> + tsadc->clk = devm_clk_get(dev, "ipg");
>> + if (IS_ERR(tsadc->clk)) {
>> + dev_err(dev, "Failed to get ipg clock\n");
>> + return PTR_ERR(tsadc->clk);
>> + }
>> +
>> + /* setup clock according to the datasheet */
>> + mx25_tsadc_setup_clk(pdev, tsadc);
>> +
>> + /* Enable clock and reset the component */
>> + regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_CLK_EN,
>> + MX25_TGCR_CLK_EN);
>> + regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_TSC_RST,
>> + MX25_TGCR_TSC_RST);
>> +
>> + /* Setup powersaving mode, but enable internal reference voltage */
>> + regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_POWERMODE_MASK,
>> + MX25_TGCR_POWERMODE_SAVE);
>> + regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_INTREFEN,
>> + MX25_TGCR_INTREFEN);
>> +
>> + ret = mx25_tsadc_setup_irq(pdev, tsadc);
>> + if (ret)
>> + return ret;
>> +
>> + platform_set_drvdata(pdev, tsadc);
>> +
>> + of_platform_populate(np, NULL, NULL, dev);
>> +
>> + 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",
>> + .of_match_table = of_match_ptr(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 <mpa-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>");
>> +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 000000000000..7fe4b8c3baac
>> --- /dev/null
>> +++ b/include/linux/mfd/imx25-tsadc.h
>> @@ -0,0 +1,140 @@
>> +#ifndef _LINUX_INCLUDE_MFD_IMX25_TSADC_H_
>> +#define _LINUX_INCLUDE_MFD_IMX25_TSADC_H_
>> +
>> +struct regmap;
>> +struct clk;
>> +
>> +struct mx25_tsadc {
>> + struct regmap *regs;
>> + struct irq_domain *domain;
>> + struct clk *clk;
>> +};
>> +
>> +#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))
>> +
>> +#define MX25_ADCQ_MR_MASK 0xffffffff
>> +
>> +/* TGCR */
>> +#define MX25_TGCR_PDBTIME(x) ((x) << 25)
>> +#define MX25_TGCR_PDBTIME_MASK GENMASK(31, 25)
>> +#define MX25_TGCR_PDBEN BIT(24)
>> +#define MX25_TGCR_PDEN BIT(23)
>> +#define MX25_TGCR_ADCCLKCFG(x) ((x) << 16)
>> +#define MX25_TGCR_GET_ADCCLK(x) (((x) >> 16) & 0x1f)
>> +#define MX25_TGCR_INTREFEN BIT(10)
>> +#define MX25_TGCR_POWERMODE_MASK GENMASK(9, 8)
>> +#define MX25_TGCR_POWERMODE_SAVE (1 << 8)
>> +#define MX25_TGCR_POWERMODE_ON (2 << 8)
>> +#define MX25_TGCR_STLC BIT(5)
>> +#define MX25_TGCR_SLPC BIT(4)
>> +#define MX25_TGCR_FUNC_RST BIT(2)
>> +#define MX25_TGCR_TSC_RST BIT(1)
>> +#define MX25_TGCR_CLK_EN BIT(0)
>> +
>> +/* TGSR */
>> +#define MX25_TGSR_SLP_INT BIT(2)
>> +#define MX25_TGSR_GCQ_INT BIT(1)
>> +#define MX25_TGSR_TCQ_INT BIT(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 BIT(19)
>> +#define MX25_ADCQ_CR_PDMSK BIT(18)
>> +#define MX25_ADCQ_CR_FRST BIT(17)
>> +#define MX25_ADCQ_CR_QRST BIT(16)
>> +#define MX25_ADCQ_CR_RWAIT_MASK GENMASK(15, 12)
>> +#define MX25_ADCQ_CR_RWAIT(x) ((x) << 12)
>> +#define MX25_ADCQ_CR_WMRK_MASK GENMASK(11, 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 BIT(3)
>> +#define MX25_ADCQ_CR_FQS BIT(2)
>> +#define MX25_ADCQ_CR_QSM_MASK GENMASK(1, 0)
>> +#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 BIT(15)
>> +#define MX25_ADCQ_SR_FULL BIT(14)
>> +#define MX25_ADCQ_SR_EMPT BIT(13)
>> +#define MX25_ADCQ_SR_FDN(x) (((x) >> 8) & 0x1f)
>> +#define MX25_ADCQ_SR_FRR BIT(6)
>> +#define MX25_ADCQ_SR_FUR BIT(5)
>> +#define MX25_ADCQ_SR_FOR BIT(4)
>> +#define MX25_ADCQ_SR_EOQ BIT(1)
>> +#define MX25_ADCQ_SR_PD BIT(0)
>> +
>> +/* ADCQ_MR (TCQMR and GCQMR) */
>> +#define MX25_ADCQ_MR_FDRY_DMA BIT(31)
>> +#define MX25_ADCQ_MR_FER_DMA BIT(22)
>> +#define MX25_ADCQ_MR_FUR_DMA BIT(21)
>> +#define MX25_ADCQ_MR_FOR_DMA BIT(20)
>> +#define MX25_ADCQ_MR_EOQ_DMA BIT(17)
>> +#define MX25_ADCQ_MR_PD_DMA BIT(16)
>> +#define MX25_ADCQ_MR_FDRY_IRQ BIT(15)
>> +#define MX25_ADCQ_MR_FER_IRQ BIT(6)
>> +#define MX25_ADCQ_MR_FUR_IRQ BIT(5)
>> +#define MX25_ADCQ_MR_FOR_IRQ BIT(4)
>> +#define MX25_ADCQ_MR_EOQ_IRQ BIT(1)
>> +#define MX25_ADCQ_MR_PD_IRQ BIT(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 GENMASK(19, 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 << 12)
>> +#define MX25_ADCQ_CFG_YPLL_OFF (1 << 12)
>> +#define MX25_ADCQ_CFG_YPLL_LOW (3 << 12)
>> +#define MX25_ADCQ_CFG_XNUR_HIGH (0 << 10)
>> +#define MX25_ADCQ_CFG_XNUR_OFF (1 << 10)
>> +#define MX25_ADCQ_CFG_XNUR_LOW (3 << 10)
>> +#define MX25_ADCQ_CFG_XPUL_HIGH (0 << 9)
>> +#define MX25_ADCQ_CFG_XPUL_OFF (1 << 9)
>> +#define MX25_ADCQ_CFG_REFP(sel) ((sel) << 7)
>> +#define MX25_ADCQ_CFG_REFP_YP MX25_ADCQ_CFG_REFP(0)
>> +#define MX25_ADCQ_CFG_REFP_XP MX25_ADCQ_CFG_REFP(1)
>> +#define MX25_ADCQ_CFG_REFP_EXT MX25_ADCQ_CFG_REFP(2)
>> +#define MX25_ADCQ_CFG_REFP_INT MX25_ADCQ_CFG_REFP(3)
>> +#define MX25_ADCQ_CFG_REFP_MASK GENMASK(8, 7)
>> +#define MX25_ADCQ_CFG_IN(sel) ((sel) << 4)
>> +#define MX25_ADCQ_CFG_IN_XP MX25_ADCQ_CFG_IN(0)
>> +#define MX25_ADCQ_CFG_IN_YP MX25_ADCQ_CFG_IN(1)
>> +#define MX25_ADCQ_CFG_IN_XN MX25_ADCQ_CFG_IN(2)
>> +#define MX25_ADCQ_CFG_IN_YN MX25_ADCQ_CFG_IN(3)
>> +#define MX25_ADCQ_CFG_IN_WIPER MX25_ADCQ_CFG_IN(4)
>> +#define MX25_ADCQ_CFG_IN_AUX0 MX25_ADCQ_CFG_IN(5)
>> +#define MX25_ADCQ_CFG_IN_AUX1 MX25_ADCQ_CFG_IN(6)
>> +#define MX25_ADCQ_CFG_IN_AUX2 MX25_ADCQ_CFG_IN(7)
>> +#define MX25_ADCQ_CFG_REFN(sel) ((sel) << 2)
>> +#define MX25_ADCQ_CFG_REFN_XN MX25_ADCQ_CFG_REFN(0)
>> +#define MX25_ADCQ_CFG_REFN_YN MX25_ADCQ_CFG_REFN(1)
>> +#define MX25_ADCQ_CFG_REFN_NGND MX25_ADCQ_CFG_REFN(2)
>> +#define MX25_ADCQ_CFG_REFN_NGND2 MX25_ADCQ_CFG_REFN(3)
>> +#define MX25_ADCQ_CFG_REFN_MASK GENMASK(3, 2)
>> +#define MX25_ADCQ_CFG_PENIACK (1 << 1)
>> +
>> +#endif /* _LINUX_INCLUDE_MFD_IMX25_TSADC_H_ */
>>
>
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