[PATCH 1/3] dm: adc: add iMX93 ADC support

Luca Ellero luca.ellero at brickedbrain.com
Fri Mar 17 09:30:52 CET 2023


On 17/03/2023 03:54, Bough Chen wrote:
>> -----Original Message-----
>> From: Luca Ellero <l.ellero at asem.it>
>> Sent: 2023年3月15日 21:36
>> To: u-boot at lists.denx.de; sbabic at denx.de; festevam at gmail.com; dl-uboot-imx
>> <uboot-imx at nxp.com>; luca.ellero at brickedbrain.com; Ye Li <ye.li at nxp.com>;
>> Peng Fan <peng.fan at nxp.com>; Bough Chen <haibo.chen at nxp.com>
>> Cc: Luca Ellero <l.ellero at asem.it>
>> Subject: [PATCH 1/3] dm: adc: add iMX93 ADC support
>>
>> This commit adds driver for iMX93 ADC.
>>
>> The driver is implemented using driver model and provides ADC uclass's methods
>> for ADC single channel operations:
>>      - adc_start_channel()
>>      - adc_channel_data()
>>      - adc_stop()
>>
>> ADC features:
>>      - channels: 4
>>      - resolution: 12-bit
>>
>> Signed-off-by: Luca Ellero <l.ellero at asem.it>
>> ---
>>   drivers/adc/Kconfig     |   8 ++
>>   drivers/adc/Makefile    |   1 +
>>   drivers/adc/imx93-adc.c | 286
>> ++++++++++++++++++++++++++++++++++++++++
>>   3 files changed, 295 insertions(+)
>>   create mode 100644 drivers/adc/imx93-adc.c
>>
>> diff --git a/drivers/adc/Kconfig b/drivers/adc/Kconfig index
>> e719c38bb3..4336732dee 100644
>> --- a/drivers/adc/Kconfig
>> +++ b/drivers/adc/Kconfig
>> @@ -63,3 +63,11 @@ config STM32_ADC
>>   	  - core driver to deal with common resources
>>   	  - child driver to deal with individual ADC resources (declare ADC
>>   	  device and associated channels, start/stop conversions)
>> +
>> +config ADC_IMX93
>> +	bool "Enable NXP IMX93 ADC driver"
>> +	help
>> +	  This enables basic driver for NXP IMX93 ADC.
>> +	  It provides:
>> +	  - 4 analog input channels
>> +	  - 12-bit resolution
>> diff --git a/drivers/adc/Makefile b/drivers/adc/Makefile index
>> c1387f3a34..5336c82097 100644
>> --- a/drivers/adc/Makefile
>> +++ b/drivers/adc/Makefile
>> @@ -10,3 +10,4 @@ obj-$(CONFIG_ADC_SANDBOX) += sandbox.o
>>   obj-$(CONFIG_SARADC_ROCKCHIP) += rockchip-saradc.o
>>   obj-$(CONFIG_SARADC_MESON) += meson-saradc.o
>>   obj-$(CONFIG_STM32_ADC) += stm32-adc.o stm32-adc-core.o
>> +obj-$(CONFIG_ADC_IMX93) += imx93-adc.o
>> diff --git a/drivers/adc/imx93-adc.c b/drivers/adc/imx93-adc.c new file mode
>> 100644 index 0000000000..b3bbea6c4e
>> --- /dev/null
>> +++ b/drivers/adc/imx93-adc.c
>> @@ -0,0 +1,286 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * Copyright (C) 2023 ASEM Srl
>> + * Author: Luca Ellero <l.ellero at asem.it>
>> + *
>> + * Originally based on NXP linux-imx kernel v5.15
>> +drivers/iio/adc/imx93_adc.c  */
>> +
>> +#include <common.h>
>> +#include <errno.h>
>> +#include <dm.h>
>> +#include <linux/bitfield.h>
>> +#include <linux/iopoll.h>
>> +#include <adc.h>
>> +
>> +#define IMX93_ADC_MCR			0x00
>> +#define IMX93_ADC_MSR			0x04
>> +#define IMX93_ADC_ISR			0x10
>> +#define IMX93_ADC_IMR			0x20
>> +#define IMX93_ADC_CIMR0			0x24
>> +#define IMX93_ADC_CTR0			0x94
>> +#define IMX93_ADC_NCMR0			0xA4
>> +#define IMX93_ADC_PCDR0			0x100
>> +#define IMX93_ADC_PCDR1			0x104
>> +#define IMX93_ADC_PCDR2			0x108
>> +#define IMX93_ADC_PCDR3			0x10c
>> +#define IMX93_ADC_PCDR4			0x110
>> +#define IMX93_ADC_PCDR5			0x114
>> +#define IMX93_ADC_PCDR6			0x118
>> +#define IMX93_ADC_PCDR7			0x11c
>> +#define IMX93_ADC_CALSTAT		0x39C
>> +
>> +#define IMX93_ADC_MCR_MODE_MASK		BIT(29)
>> +#define IMX93_ADC_MCR_NSTART_MASK	BIT(24)
>> +#define IMX93_ADC_MCR_CALSTART_MASK	BIT(14)
>> +#define IMX93_ADC_MCR_ADCLKSE_MASK	BIT(8)
>> +#define IMX93_ADC_MCR_PWDN_MASK		BIT(0)
>> +
>> +#define IMX93_ADC_MSR_CALFAIL_MASK	BIT(30)
>> +#define IMX93_ADC_MSR_CALBUSY_MASK	BIT(29)
>> +#define IMX93_ADC_MSR_ADCSTATUS_MASK	GENMASK(2, 0)
>> +
>> +#define IMX93_ADC_ISR_EOC_MASK		BIT(1)
>> +
>> +#define IMX93_ADC_IMR_EOC_MASK		BIT(1)
>> +#define IMX93_ADC_IMR_ECH_MASK		BIT(0)
>> +
>> +#define IMX93_ADC_PCDR_CDATA_MASK	GENMASK(11, 0)
>> +
>> +#define IDLE				0
>> +#define POWER_DOWN			1
>> +#define WAIT_STATE			2
>> +#define BUSY_IN_CALIBRATION		3
>> +#define SAMPLE				4
>> +#define CONVERSION			6
>> +
>> +#define IMX93_ADC_MAX_CHANNEL		3
>> +#define IMX93_ADC_DAT_MASK		0xfff
>> +#define IMX93_ADC_TIMEOUT		100000
>> +
>> +struct imx93_adc_priv {
>> +	int active_channel;
>> +	void __iomem *regs;
>> +};
>> +
>> +static int imx93_adc_power_down(struct imx93_adc_priv *adc) {
>> +	u32 mcr, msr;
>> +	int ret;
>> +
>> +	mcr = readl(adc->regs + IMX93_ADC_MCR);
>> +	mcr |= FIELD_PREP(IMX93_ADC_MCR_PWDN_MASK, 1);
>> +	writel(mcr, adc->regs + IMX93_ADC_MCR);
>> +
>> +	ret = readl_poll_timeout(adc->regs + IMX93_ADC_MSR, msr,
>> +		((msr & IMX93_ADC_MSR_ADCSTATUS_MASK) == POWER_DOWN),
>> 50);
>> +	if (ret == -ETIMEDOUT)
>> +		pr_warn("ADC not in power down mode, current MSR: %x\n", msr);
>> +
>> +	return ret;
>> +}
>> +
>> +static int imx93_adc_config_ad_clk(struct imx93_adc_priv *adc) {
>> +	u32 mcr;
>> +	int ret;
>> +
>> +	/* put adc in power down mode */
>> +	ret = imx93_adc_power_down(adc);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	/* config the AD_CLK equal to bus clock */
>> +	mcr = readl(adc->regs + IMX93_ADC_MCR);
>> +	mcr |= FIELD_PREP(IMX93_ADC_MCR_ADCLKSE_MASK, 1);
>> +	writel(mcr, adc->regs + IMX93_ADC_MCR);
>> +
>> +	/* bring ADC out of power down state, in idle state */
>> +	mcr = readl(adc->regs + IMX93_ADC_MCR);
>> +	mcr &= ~FIELD_PREP(IMX93_ADC_MCR_PWDN_MASK, 1);
>> +	writel(mcr, adc->regs + IMX93_ADC_MCR);
> 
> Few same code in the following, better to use a function like imx93_adc_power_up() to do this.
> 
> You can refer to latest upstream linux imx93 ADC version, seems you just refer to the downstream driver.
> https://elixir.bootlin.com/linux/v6.3-rc2/source/drivers/iio/adc/imx93_adc.c
> 
>> +
>> +	return ret;
>> +}
>> +
>> +static int imx93_adc_calibration(struct imx93_adc_priv *adc) {
>> +	u32 mcr, msr, adc_status;
>> +	int ret;
>> +
>> +	/* make sure ADC is in power down mode */
>> +	msr = readl(adc->regs + IMX93_ADC_MSR);
>> +
>> +	adc_status = FIELD_GET(IMX93_ADC_MSR_ADCSTATUS_MASK, msr);
>> +	if (adc_status != POWER_DOWN) {
>> +		ret = imx93_adc_power_down(adc);
>> +		if (ret < 0)
>> +			return ret;
>> +	}
> 
> Directly power down the adc to simplify the code logic.
> 
>> +
>> +	/* config SAR controller operating clock */
>> +	mcr = readl(adc->regs + IMX93_ADC_MCR);
>> +	mcr &= ~FIELD_PREP(IMX93_ADC_MCR_ADCLKSE_MASK, 1);
>> +	writel(mcr, adc->regs + IMX93_ADC_MCR);
>> +
>> +	/* bring ADC out of power down state */
>> +	mcr = readl(adc->regs + IMX93_ADC_MCR);
>> +	mcr &= ~FIELD_PREP(IMX93_ADC_MCR_PWDN_MASK, 1);
>> +	writel(mcr, adc->regs + IMX93_ADC_MCR);
> 
> Use the function adc power up, to reduce the redundant code.
> 
>> +
>> +	/*
>> +	 * we use the default TSAMP/NRSMPL/AVGEN in MCR,
>> +	 * can add the setting of these bit if need
>> +	 */
>> +
>> +	/* run calibration */
>> +	mcr = readl(adc->regs + IMX93_ADC_MCR);
>> +	mcr |= FIELD_PREP(IMX93_ADC_MCR_CALSTART_MASK, 1);
>> +	writel(mcr, adc->regs + IMX93_ADC_MCR);
>> +
>> +	/* wait calibration to be finished */
>> +	ret = readl_poll_timeout(adc->regs + IMX93_ADC_MSR, msr,
>> +		!(msr & IMX93_ADC_MSR_CALBUSY_MASK), 2000000);
>> +	if (ret == -ETIMEDOUT) {
>> +		pr_warn("ADC calibration timeout\n");
>> +		return ret;
>> +	}
>> +
>> +	/* check whether calbration is successful or not */
>> +	msr = readl(adc->regs + IMX93_ADC_MSR);
>> +	if (msr & IMX93_ADC_MSR_CALFAIL_MASK) {
>> +		pr_warn("ADC calibration failed!\n");
>> +		return -EAGAIN;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int imx93_adc_channel_data(struct udevice *dev, int channel,
>> +			    unsigned int *data)
>> +{
>> +	struct imx93_adc_priv *adc = dev_get_priv(dev);
>> +	u32 isr, pcda;
>> +	int ret;
>> +
>> +	if (channel != adc->active_channel) {
>> +		pr_err("Requested channel is not active!\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	ret = readl_poll_timeout(adc->regs + IMX93_ADC_ISR, isr,
>> +		(isr & IMX93_ADC_ISR_EOC_MASK), IMX93_ADC_TIMEOUT);
>> +
>> +	/* clear interrupts */
>> +	writel(isr, adc->regs + IMX93_ADC_ISR);
>> +
>> +	if (ret == -ETIMEDOUT) {
>> +		pr_warn("ADC conversion timeout!\n");
>> +		return ret;
>> +	}
>> +
>> +	pcda = readl(adc->regs + IMX93_ADC_PCDR0 + channel * 4);
>> +
>> +	*data = FIELD_GET(IMX93_ADC_PCDR_CDATA_MASK, pcda);
>> +
>> +	return 0;
>> +}
>> +
>> +static int imx93_adc_start_channel(struct udevice *dev, int channel) {
>> +	struct imx93_adc_priv *adc = dev_get_priv(dev);
>> +	u32 imr, mcr;
>> +
>> +	/* config channel mask register */
>> +	writel(1 << channel, adc->regs + IMX93_ADC_NCMR0);
>> +
>> +	/* config interrupt mask */
>> +	imr = FIELD_PREP(IMX93_ADC_IMR_EOC_MASK, 1);
>> +	writel(imr, adc->regs + IMX93_ADC_IMR);
>> +	writel(1 << channel, adc->regs + IMX93_ADC_CIMR0);
>> +
>> +	/* config one-shot mode */
>> +	mcr = readl(adc->regs + IMX93_ADC_MCR);
>> +	mcr &= ~FIELD_PREP(IMX93_ADC_MCR_MODE_MASK, 1);
>> +	writel(mcr, adc->regs + IMX93_ADC_MCR);
>> +
>> +	/* start normal conversion */
>> +	mcr = readl(adc->regs + IMX93_ADC_MCR);
>> +	mcr |= FIELD_PREP(IMX93_ADC_MCR_NSTART_MASK, 1);
>> +	writel(mcr, adc->regs + IMX93_ADC_MCR);
>> +
>> +	adc->active_channel = channel;
>> +
>> +	return 0;
>> +}
>> +
>> +static int imx93_adc_stop(struct udevice *dev) {
>> +	struct imx93_adc_priv *adc = dev_get_priv(dev);
>> +
>> +	imx93_adc_power_down(adc);
>> +
>> +	adc->active_channel = -1;
>> +
>> +	return 0;
>> +}
>> +
>> +static int imx93_adc_probe(struct udevice *dev) {
>> +	struct imx93_adc_priv *adc = dev_get_priv(dev);
>> +	unsigned int ret;
>> +
>> +	ret = imx93_adc_calibration(adc);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	ret = imx93_adc_config_ad_clk(adc);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	adc->active_channel = -1;
>> +
>> +	return 0;
>> +}
>> +
>> +static int imx93_adc_of_to_plat(struct udevice *dev) {
>> +	struct adc_uclass_plat *uc_pdata = dev_get_uclass_plat(dev);
>> +	struct imx93_adc_priv *adc = dev_get_priv(dev);
>> +
>> +	adc->regs = dev_read_addr_ptr(dev);
>> +	if (adc->regs == (struct imx93_adc *)FDT_ADDR_T_NONE) {
>> +		pr_err("Dev: %s - can't get address!", dev->name);
>> +		return -ENODATA;
>> +	}
>> +
>> +	uc_pdata->data_mask = IMX93_ADC_DAT_MASK;
>> +	uc_pdata->data_format = ADC_DATA_FORMAT_BIN;
>> +	uc_pdata->data_timeout_us = IMX93_ADC_TIMEOUT;
>> +
>> +	/* Mask available channel bits: [0:3] */
>> +	uc_pdata->channel_mask = (2 << IMX93_ADC_MAX_CHANNEL) - 1;
> 
> Seems you forget to handle the ADC ipg clock: IMX93_CLK_ADC1_GATE, please add it in the driver.
> 
> Best Regards
> Haibo Chen
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct adc_ops imx93_adc_ops = {
>> +	.start_channel = imx93_adc_start_channel,
>> +	.channel_data = imx93_adc_channel_data,
>> +	.stop = imx93_adc_stop,
>> +};
>> +
>> +static const struct udevice_id imx93_adc_ids[] = {
>> +	{ .compatible = "nxp,imx93-adc" },
>> +	{ }
>> +};
>> +
>> +U_BOOT_DRIVER(imx93_adc) = {
>> +	.name		= "imx93-adc",
>> +	.id		= UCLASS_ADC,
>> +	.of_match	= imx93_adc_ids,
>> +	.ops		= &imx93_adc_ops,
>> +	.probe		= imx93_adc_probe,
>> +	.of_to_plat	= imx93_adc_of_to_plat,
>> +	.priv_auto	= sizeof(struct imx93_adc_priv),
>> +};
>> --
>> 2.25.1
> 

Hi Haibo,
thanks for your suggestions.
I will fix and resend.
Luca Ellero



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