Re: [PATCH v3 2/6] iio: adc: Add support for STM32 ADC core

From: Jonathan Cameron
Date: Thu Nov 24 2016 - 15:40:32 EST

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On 21/11/16 08:54, Fabrice Gasnier wrote:
> On 11/19/2016 01:17 PM, Jonathan Cameron wrote:
>> On 15/11/16 15:30, Fabrice Gasnier wrote:
>>> Add core driver for STMicroelectronics STM32 ADC (Analog to Digital
>>> Converter). STM32 ADC can be composed of up to 3 ADCs with shared
>>> resources like clock prescaler, common interrupt line and analog
>>> reference voltage.
>>> This core driver basically manages shared resources.
>>>
>>> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx>
>> There is nothing in here that demands selecting a fixed regulator.
>> I've also switched the select regulator over to depends on inline with
>> other drivers in IIO that have a hard dependency on regulators.
>> Other than that which showed up during build tests, looks good to me.
>> Shout if I've broken anything with this change.
>
> Hi Jonathan, All,
>
> First many thanks.
> This is not a big deal. Only thing is: I think patch 4 of this series (on stm32_defconfig) need to be updated
> to accommodate this change. E.g. :
> +CONFIG_REGULATOR=y
> +CONFIG_REGULATOR_FIXED_VOLTAGE=y
>
> Shall I send a new version of this series (all patches), including your changes, with updated defconfig as well ?
> Or only updated patch on defconfig is enough ?
Just update those that haven't already been applied.

Thanks,

Jonathan
>
> Please advise,
> Fabrice
>>
>> Applied to the togreg branch of iio.git and pushed out as testing for
>> the autobuilders to play with it.
>>
>> Thanks,
>>
>> Jonathan
>>> ---
>>> drivers/iio/adc/Kconfig | 13 ++
>>> drivers/iio/adc/Makefile | 1 +
>>> drivers/iio/adc/stm32-adc-core.c | 303 +++++++++++++++++++++++++++++++++++++++
>>> drivers/iio/adc/stm32-adc-core.h | 52 +++++++
>>> 4 files changed, 369 insertions(+)
>>> create mode 100644 drivers/iio/adc/stm32-adc-core.c
>>> create mode 100644 drivers/iio/adc/stm32-adc-core.h
>>>
>>> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
>>> index 7edcf32..ff30239 100644
>>> --- a/drivers/iio/adc/Kconfig
>>> +++ b/drivers/iio/adc/Kconfig
>>> @@ -419,6 +419,19 @@ config ROCKCHIP_SARADC
>>> To compile this driver as a module, choose M here: the
>>> module will be called rockchip_saradc.
>>> +config STM32_ADC_CORE
>>> + tristate "STMicroelectronics STM32 adc core"
>>> + depends on ARCH_STM32 || COMPILE_TEST
>>> + depends on OF
>>> + select REGULATOR
>>> + select REGULATOR_FIXED_VOLTAGE
>>> + help
>>> + Select this option to enable the core driver for STMicroelectronics
>>> + STM32 analog-to-digital converter (ADC).
>>> +
>>> + This driver can also be built as a module. If so, the module
>>> + will be called stm32-adc-core.
>>> +
>>> config STX104
>>> tristate "Apex Embedded Systems STX104 driver"
>>> depends on X86 && ISA_BUS_API
>>> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
>>> index 7a40c04..a1e8f44 100644
>>> --- a/drivers/iio/adc/Makefile
>>> +++ b/drivers/iio/adc/Makefile
>>> @@ -41,6 +41,7 @@ obj-$(CONFIG_QCOM_SPMI_IADC) += qcom-spmi-iadc.o
>>> obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
>>> obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
>>> obj-$(CONFIG_STX104) += stx104.o
>>> +obj-$(CONFIG_STM32_ADC_CORE) += stm32-adc-core.o
>>> obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
>>> obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o
>>> obj-$(CONFIG_TI_ADC12138) += ti-adc12138.o
>>> diff --git a/drivers/iio/adc/stm32-adc-core.c b/drivers/iio/adc/stm32-adc-core.c
>>> new file mode 100644
>>> index 0000000..4214b0c
>>> --- /dev/null
>>> +++ b/drivers/iio/adc/stm32-adc-core.c
>>> @@ -0,0 +1,303 @@
>>> +/*
>>> + * This file is part of STM32 ADC driver
>>> + *
>>> + * Copyright (C) 2016, STMicroelectronics - All Rights Reserved
>>> + * Author: Fabrice Gasnier <fabrice.gasnier@xxxxxx>.
>>> + *
>>> + * Inspired from: fsl-imx25-tsadc
>>> + *
>>> + * License type: GPLv2
>>> + *
>>> + * 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.
>>> + *
>>> + * This program is distributed in the hope that it will be useful, but
>>> + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
>>> + * or FITNESS FOR A PARTICULAR PURPOSE.
>>> + * See the GNU General Public License for more details.
>>> + *
>>> + * You should have received a copy of the GNU General Public License along with
>>> + * this program. If not, see <http://www.gnu.org/licenses/>.
>>> + */
>>> +
>>> +#include <linux/clk.h>
>>> +#include <linux/interrupt.h>
>>> +#include <linux/irqchip/chained_irq.h>
>>> +#include <linux/irqdesc.h>
>>> +#include <linux/irqdomain.h>
>>> +#include <linux/module.h>
>>> +#include <linux/of_device.h>
>>> +#include <linux/regulator/consumer.h>
>>> +#include <linux/slab.h>
>>> +
>>> +#include "stm32-adc-core.h"
>>> +
>>> +/* STM32F4 - common registers for all ADC instances: 1, 2 & 3 */
>>> +#define STM32F4_ADC_CSR (STM32_ADCX_COMN_OFFSET + 0x00)
>>> +#define STM32F4_ADC_CCR (STM32_ADCX_COMN_OFFSET + 0x04)
>>> +
>>> +/* STM32F4_ADC_CSR - bit fields */
>>> +#define STM32F4_EOC3 BIT(17)
>>> +#define STM32F4_EOC2 BIT(9)
>>> +#define STM32F4_EOC1 BIT(1)
>>> +
>>> +/* STM32F4_ADC_CCR - bit fields */
>>> +#define STM32F4_ADC_ADCPRE_SHIFT 16
>>> +#define STM32F4_ADC_ADCPRE_MASK GENMASK(17, 16)
>>> +
>>> +/* STM32 F4 maximum analog clock rate (from datasheet) */
>>> +#define STM32F4_ADC_MAX_CLK_RATE 36000000
>>> +
>>> +/**
>>> + * struct stm32_adc_priv - stm32 ADC core private data
>>> + * @irq: irq for ADC block
>>> + * @domain: irq domain reference
>>> + * @aclk: clock reference for the analog circuitry
>>> + * @vref: regulator reference
>>> + * @common: common data for all ADC instances
>>> + */
>>> +struct stm32_adc_priv {
>>> + int irq;
>>> + struct irq_domain *domain;
>>> + struct clk *aclk;
>>> + struct regulator *vref;
>>> + struct stm32_adc_common common;
>>> +};
>>> +
>>> +static struct stm32_adc_priv *to_stm32_adc_priv(struct stm32_adc_common *com)
>>> +{
>>> + return container_of(com, struct stm32_adc_priv, common);
>>> +}
>>> +
>>> +/* STM32F4 ADC internal common clock prescaler division ratios */
>>> +static int stm32f4_pclk_div[] = {2, 4, 6, 8};
>>> +
>>> +/**
>>> + * stm32f4_adc_clk_sel() - Select stm32f4 ADC common clock prescaler
>>> + * @priv: stm32 ADC core private data
>>> + * Select clock prescaler used for analog conversions, before using ADC.
>>> + */
>>> +static int stm32f4_adc_clk_sel(struct platform_device *pdev,
>>> + struct stm32_adc_priv *priv)
>>> +{
>>> + unsigned long rate;
>>> + u32 val;
>>> + int i;
>>> +
>>> + rate = clk_get_rate(priv->aclk);
>>> + for (i = 0; i < ARRAY_SIZE(stm32f4_pclk_div); i++) {
>>> + if ((rate / stm32f4_pclk_div[i]) <= STM32F4_ADC_MAX_CLK_RATE)
>>> + break;
>>> + }
>>> + if (i >= ARRAY_SIZE(stm32f4_pclk_div))
>>> + return -EINVAL;
>>> +
>>> + val = readl_relaxed(priv->common.base + STM32F4_ADC_CCR);
>>> + val &= ~STM32F4_ADC_ADCPRE_MASK;
>>> + val |= i << STM32F4_ADC_ADCPRE_SHIFT;
>>> + writel_relaxed(val, priv->common.base + STM32F4_ADC_CCR);
>>> +
>>> + dev_dbg(&pdev->dev, "Using analog clock source at %ld kHz\n",
>>> + rate / (stm32f4_pclk_div[i] * 1000));
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +/* ADC common interrupt for all instances */
>>> +static void stm32_adc_irq_handler(struct irq_desc *desc)
>>> +{
>>> + struct stm32_adc_priv *priv = irq_desc_get_handler_data(desc);
>>> + struct irq_chip *chip = irq_desc_get_chip(desc);
>>> + u32 status;
>>> +
>>> + chained_irq_enter(chip, desc);
>>> + status = readl_relaxed(priv->common.base + STM32F4_ADC_CSR);
>>> +
>>> + if (status & STM32F4_EOC1)
>>> + generic_handle_irq(irq_find_mapping(priv->domain, 0));
>>> +
>>> + if (status & STM32F4_EOC2)
>>> + generic_handle_irq(irq_find_mapping(priv->domain, 1));
>>> +
>>> + if (status & STM32F4_EOC3)
>>> + generic_handle_irq(irq_find_mapping(priv->domain, 2));
>>> +
>>> + chained_irq_exit(chip, desc);
>>> +};
>>> +
>>> +static int stm32_adc_domain_map(struct irq_domain *d, unsigned int irq,
>>> + irq_hw_number_t hwirq)
>>> +{
>>> + irq_set_chip_data(irq, d->host_data);
>>> + irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_level_irq);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static void stm32_adc_domain_unmap(struct irq_domain *d, unsigned int irq)
>>> +{
>>> + irq_set_chip_and_handler(irq, NULL, NULL);
>>> + irq_set_chip_data(irq, NULL);
>>> +}
>>> +
>>> +static const struct irq_domain_ops stm32_adc_domain_ops = {
>>> + .map = stm32_adc_domain_map,
>>> + .unmap = stm32_adc_domain_unmap,
>>> + .xlate = irq_domain_xlate_onecell,
>>> +};
>>> +
>>> +static int stm32_adc_irq_probe(struct platform_device *pdev,
>>> + struct stm32_adc_priv *priv)
>>> +{
>>> + struct device_node *np = pdev->dev.of_node;
>>> +
>>> + priv->irq = platform_get_irq(pdev, 0);
>>> + if (priv->irq < 0) {
>>> + dev_err(&pdev->dev, "failed to get irq\n");
>>> + return priv->irq;
>>> + }
>>> +
>>> + priv->domain = irq_domain_add_simple(np, STM32_ADC_MAX_ADCS, 0,
>>> + &stm32_adc_domain_ops,
>>> + priv);
>>> + if (!priv->domain) {
>>> + dev_err(&pdev->dev, "Failed to add irq domain\n");
>>> + return -ENOMEM;
>>> + }
>>> +
>>> + irq_set_chained_handler(priv->irq, stm32_adc_irq_handler);
>>> + irq_set_handler_data(priv->irq, priv);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static void stm32_adc_irq_remove(struct platform_device *pdev,
>>> + struct stm32_adc_priv *priv)
>>> +{
>>> + int hwirq;
>>> +
>>> + for (hwirq = 0; hwirq < STM32_ADC_MAX_ADCS; hwirq++)
>>> + irq_dispose_mapping(irq_find_mapping(priv->domain, hwirq));
>>> + irq_domain_remove(priv->domain);
>>> + irq_set_chained_handler(priv->irq, NULL);
>>> +}
>>> +
>>> +static int stm32_adc_probe(struct platform_device *pdev)
>>> +{
>>> + struct stm32_adc_priv *priv;
>>> + struct device_node *np = pdev->dev.of_node;
>>> + struct resource *res;
>>> + int ret;
>>> +
>>> + if (!pdev->dev.of_node)
>>> + return -ENODEV;
>>> +
>>> + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
>>> + if (!priv)
>>> + return -ENOMEM;
>>> +
>>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> + priv->common.base = devm_ioremap_resource(&pdev->dev, res);
>>> + if (IS_ERR(priv->common.base))
>>> + return PTR_ERR(priv->common.base);
>>> +
>>> + priv->vref = devm_regulator_get(&pdev->dev, "vref");
>>> + if (IS_ERR(priv->vref)) {
>>> + ret = PTR_ERR(priv->vref);
>>> + dev_err(&pdev->dev, "vref get failed, %d\n", ret);
>>> + return ret;
>>> + }
>>> +
>>> + ret = regulator_enable(priv->vref);
>>> + if (ret < 0) {
>>> + dev_err(&pdev->dev, "vref enable failed\n");
>>> + return ret;
>>> + }
>>> +
>>> + ret = regulator_get_voltage(priv->vref);
>>> + if (ret < 0) {
>>> + dev_err(&pdev->dev, "vref get voltage failed, %d\n", ret);
>>> + goto err_regulator_disable;
>>> + }
>>> + priv->common.vref_mv = ret / 1000;
>>> + dev_dbg(&pdev->dev, "vref+=%dmV\n", priv->common.vref_mv);
>>> +
>>> + priv->aclk = devm_clk_get(&pdev->dev, "adc");
>>> + if (IS_ERR(priv->aclk)) {
>>> + ret = PTR_ERR(priv->aclk);
>>> + dev_err(&pdev->dev, "Can't get 'adc' clock\n");
>>> + goto err_regulator_disable;
>>> + }
>>> +
>>> + ret = clk_prepare_enable(priv->aclk);
>>> + if (ret < 0) {
>>> + dev_err(&pdev->dev, "adc clk enable failed\n");
>>> + goto err_regulator_disable;
>>> + }
>>> +
>>> + ret = stm32f4_adc_clk_sel(pdev, priv);
>>> + if (ret < 0) {
>>> + dev_err(&pdev->dev, "adc clk selection failed\n");
>>> + goto err_clk_disable;
>>> + }
>>> +
>>> + ret = stm32_adc_irq_probe(pdev, priv);
>>> + if (ret < 0)
>>> + goto err_clk_disable;
>>> +
>>> + platform_set_drvdata(pdev, &priv->common);
>>> +
>>> + ret = of_platform_populate(np, NULL, NULL, &pdev->dev);
>>> + if (ret < 0) {
>>> + dev_err(&pdev->dev, "failed to populate DT children\n");
>>> + goto err_irq_remove;
>>> + }
>>> +
>>> + return 0;
>>> +
>>> +err_irq_remove:
>>> + stm32_adc_irq_remove(pdev, priv);
>>> +
>>> +err_clk_disable:
>>> + clk_disable_unprepare(priv->aclk);
>>> +
>>> +err_regulator_disable:
>>> + regulator_disable(priv->vref);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static int stm32_adc_remove(struct platform_device *pdev)
>>> +{
>>> + struct stm32_adc_common *common = platform_get_drvdata(pdev);
>>> + struct stm32_adc_priv *priv = to_stm32_adc_priv(common);
>>> +
>>> + of_platform_depopulate(&pdev->dev);
>>> + stm32_adc_irq_remove(pdev, priv);
>>> + clk_disable_unprepare(priv->aclk);
>>> + regulator_disable(priv->vref);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static const struct of_device_id stm32_adc_of_match[] = {
>>> + { .compatible = "st,stm32f4-adc-core" },
>>> + {},
>>> +};
>>> +MODULE_DEVICE_TABLE(of, stm32_adc_of_match);
>>> +
>>> +static struct platform_driver stm32_adc_driver = {
>>> + .probe = stm32_adc_probe,
>>> + .remove = stm32_adc_remove,
>>> + .driver = {
>>> + .name = "stm32-adc-core",
>>> + .of_match_table = stm32_adc_of_match,
>>> + },
>>> +};
>>> +module_platform_driver(stm32_adc_driver);
>>> +
>>> +MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@xxxxxx>");
>>> +MODULE_DESCRIPTION("STMicroelectronics STM32 ADC core driver");
>>> +MODULE_LICENSE("GPL v2");
>>> +MODULE_ALIAS("platform:stm32-adc-core");
>>> diff --git a/drivers/iio/adc/stm32-adc-core.h b/drivers/iio/adc/stm32-adc-core.h
>>> new file mode 100644
>>> index 0000000..081fa5f
>>> --- /dev/null
>>> +++ b/drivers/iio/adc/stm32-adc-core.h
>>> @@ -0,0 +1,52 @@
>>> +/*
>>> + * This file is part of STM32 ADC driver
>>> + *
>>> + * Copyright (C) 2016, STMicroelectronics - All Rights Reserved
>>> + * Author: Fabrice Gasnier <fabrice.gasnier@xxxxxx>.
>>> + *
>>> + * License type: GPLv2
>>> + *
>>> + * 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.
>>> + *
>>> + * This program is distributed in the hope that it will be useful, but
>>> + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
>>> + * or FITNESS FOR A PARTICULAR PURPOSE.
>>> + * See the GNU General Public License for more details.
>>> + *
>>> + * You should have received a copy of the GNU General Public License along with
>>> + * this program. If not, see <http://www.gnu.org/licenses/>.
>>> + */
>>> +
>>> +#ifndef __STM32_ADC_H
>>> +#define __STM32_ADC_H
>>> +
>>> +/*
>>> + * STM32 - ADC global register map
>>> + * ________________________________________________________
>>> + * | Offset | Register |
>>> + * --------------------------------------------------------
>>> + * | 0x000 | Master ADC1 |
>>> + * --------------------------------------------------------
>>> + * | 0x100 | Slave ADC2 |
>>> + * --------------------------------------------------------
>>> + * | 0x200 | Slave ADC3 |
>>> + * --------------------------------------------------------
>>> + * | 0x300 | Master & Slave common regs |
>>> + * --------------------------------------------------------
>>> + */
>>> +#define STM32_ADC_MAX_ADCS 3
>>> +#define STM32_ADCX_COMN_OFFSET 0x300
>>> +
>>> +/**
>>> + * struct stm32_adc_common - stm32 ADC driver common data (for all instances)
>>> + * @base: control registers base cpu addr
>>> + * @vref_mv: vref voltage (mv)
>>> + */
>>> +struct stm32_adc_common {
>>> + void __iomem *base;
>>> + int vref_mv;
>>> +};
>>> +
>>> +#endif
>>>
>
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Next message: Jonathan Cameron: "Re: [PATCH v2] iio: magnetometer: separate the values of attributes based on their usage type for HID compass sensor"
Previous message: Al Viro: "Re: [PATCH 1/1 linux-next] ext4: add compatibility flag check"
Next in thread: Fabrice Gasnier: "Re: [PATCH v3 2/6] iio: adc: Add support for STM32 ADC core"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]