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

Bough Chen haibo.chen at nxp.com
Tue Mar 14 04:03:43 CET 2023


> -----Original Message-----
> From: Luca Ellero <l.ellero at asem.it>
> Sent: 2023年3月13日 21:06
> 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 | 284
> ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 293 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..c5f0268eca
> --- /dev/null
> +++ b/drivers/adc/imx93-adc.c
> @@ -0,0 +1,284 @@
> +// 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);
> +
> +	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;
> +	}
> +
> +	/* 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);
> +
> +	/*
> +	 * 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);
> +

Better to add imx93_adc_power_down() here.

Best Regards
Haibo Chen
> +	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;
> +
> +	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



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