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From:   Cai Huoqing <caihuoqing@baidu.com>
To:     <jic23@kernel.org>, <lars@metafoo.de>, <robh+dt@kernel.org>,
        <shawnguo@kernel.org>, <s.hauer@pengutronix.de>,
        <kernel@pengutronix.de>, <festevam@gmail.com>, <linux-imx@nxp.com>,
        <alex.dewar90@gmail.com>
CC:     <linux-iio@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>,
        "Cai Huoqing" <caihuoqing@baidu.com>
Subject: [PATCH 3/6] iio: imx8qxp-adc: Add the detail for NXP i.MX8QuadXPlus ADC driver
Date:   Tue, 31 Aug 2021 01:21:37 +0800
Message-ID: <20210830172140.414-4-caihuoqing@baidu.com>
In-Reply-To: <20210830172140.414-1-caihuoqing@baidu.com>
References: <20210830172140.414-1-caihuoqing@baidu.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

The NXP i.MX 8QuadXPlus SOC has a new ADC IP, so add the detail for NXP
i.MX8QuadXPlus ADC driver which includes: probe/remove/pm_ops/iio_dev.

Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
---
 drivers/iio/adc/imx8qxp-adc.c | 513 ++++++++++++++++++++++++++++++++++
 1 file changed, 513 insertions(+)

diff --git a/drivers/iio/adc/imx8qxp-adc.c b/drivers/iio/adc/imx8qxp-adc.c
index aec1b45c8fb9..d39bf382c582 100644
--- a/drivers/iio/adc/imx8qxp-adc.c
+++ b/drivers/iio/adc/imx8qxp-adc.c
@@ -20,23 +20,536 @@
 
 #define ADC_DRIVER_NAME		"imx8qxp-adc"
 
+/* Register map definition */
+#define ADC_CTRL		0x10
+#define ADC_STAT		0x14
+#define ADC_IE			0x18
+#define ADC_DE			0x1c
+#define ADC_CFG			0x20
+#define ADC_FCTRL		0x30
+#define ADC_SWTRIG		0x34
+#define ADC_TCTRL(tid)		(0xc0 + tid * 4)
+#define ADC_CMDH(cid)		(0x100 + cid * 8)
+#define ADC_CMDL(cid)		(0x104 + cid * 8)
+#define ADC_RESFIFO		0x300
+#define ADC_TST			0xffc
+
+/* ADC bit shift */
+#define ADC_IE_FWMIE_SHIFT		(0)
+#define ADC_CTRL_FIFO_RESET_SHIFT	(8)
+#define ADC_CTRL_SOFTWARE_RESET_SHIFT	(1)
+#define ADC_CTRL_ADC_ENABLE		(0)
+#define ADC_TCTRL_TCMD_SHIFT		(24)
+#define ADC_TCTRL_TDLY_SHIFT		(16)
+#define ADC_TCTRL_TPRI_SHIFT		(8)
+#define ADC_TCTRL_HTEN_SHIFT		(0)
+#define ADC_CMDL_CSCALE_SHIFT		(8)
+#define ADC_CMDL_MODE_SHIFT		(7)
+#define ADC_CMDL_DIFF_SHIFT		(6)
+#define ADC_CMDL_ABSEL_SHIFT		(5)
+#define ADC_CMDL_ADCH_SHIFT		(0)
+#define ADC_CMDH_NEXT_SHIFT		(24)
+#define ADC_CMDH_LOOP_SHIFT		(16)
+#define ADC_CMDH_AVGS_SHIFT		(12)
+#define ADC_CMDH_STS_SHIFT		(8)
+#define ADC_CMDH_LWI_SHIFT		(7)
+#define ADC_CMDH_CMPEN_SHIFT		(0)
+#define ADC_CFG_PWREN_SHIFT		(28)
+#define ADC_CFG_PUDLY_SHIFT		(16)
+#define ADC_CFG_REFSEL_SHIFT		(6)
+#define ADC_CFG_PWRSEL_SHIFT		(4)
+#define ADC_CFG_TPRICTRL_SHIFT		(0)
+#define ADC_FCTRL_FWMARK_SHIFT		(16)
+#define ADC_FCTRL_FWMARK_MASK		(0x1f << 16)
+#define ADC_FCTRL_FCOUNT_MASK		(0x1f)
+
+/* ADC PARAMETER*/
+#define ADC_CMDL_CHANNEL_SCALE_FULL		(0x3f)
+#define ADC_CMDL_SEL_A_A_B_CHANNEL		(0)
+#define ADC_CMDL_STANDARD_RESOLUTION		(0)
+#define ADC_CMDL_MODE_SINGLE			(0)
+#define ADC_CMDH_LWI_INCREMENT_DISABLE		(0)
+#define ADC_CMDH_CMPEN_DISABLE			(0)
+#define ADC_PAUSE_ENABLE			(0x80000000)
+#define ADC_TCTRL_TPRI_PRIORITY_HIGH		(0)
+
+#define ADC_TCTRL_HTEN_HARDWARE_TIRGGER_DISABLE	(0)
+
+#define MAX_CMD (8)
+#define MAX_TRIG (8)
+
+#define ADC_TIMEOUT		msecs_to_jiffies(100)
+
+struct imx8qxp_adc_trigger_ctrl {
+	u32 tcmd;
+	u32 tdly;
+	u32 tpri;
+	u32 hten;
+};
+
+struct imx8qxp_adc_cmd_l {
+	u32 scale;
+	u32 mode;
+	u32 diff;
+	u32 absel;
+	u32 adch;
+};
+
+struct imx8qxp_adc_cmd_h {
+	u32 next;
+	u32 loop;
+	u32 avgs;
+	u32 sts;
+	u32 lwi;
+	u32 cmpen;
+};
+
+struct imx8qxp_adc_cfg {
+	u32 pwren;
+	u32 pudly;
+	u32 refsel;
+	u32 pwrsel;
+	u32 tprictrl;
+};
+
+struct imx8qxp_adc {
+	struct device *dev;
+	void __iomem *regs;
+	struct clk *clk;
+	struct clk *ipg_clk;
+
+	u32 vref_uv;
+	u32 value;
+	u32 channel_id;
+	u32 trigger_id;
+	u32 cmd_id;
+
+	struct regulator *vref;
+	struct imx8qxp_adc_cmd_l adc_cmd_l[MAX_CMD + 1];
+	struct imx8qxp_adc_cmd_h adc_cmd_h[MAX_CMD + 1];
+	struct imx8qxp_adc_trigger_ctrl adc_trigger_ctrl[MAX_TRIG + 1];
+	struct imx8qxp_adc_cfg adc_cfg;
+	struct completion completion;
+};
+
+#define IMX8QXP_ADC_CHAN(_idx) {				\
+	.type = IIO_VOLTAGE,					\
+	.indexed = 1,						\
+	.channel = (_idx),					\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |	\
+				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
+}
+
+static const struct iio_chan_spec imx8qxp_adc_iio_channels[] = {
+	IMX8QXP_ADC_CHAN(0),
+	IMX8QXP_ADC_CHAN(1),
+	IMX8QXP_ADC_CHAN(2),
+	IMX8QXP_ADC_CHAN(3),
+	IMX8QXP_ADC_CHAN(4),
+	IMX8QXP_ADC_CHAN(5),
+	IMX8QXP_ADC_CHAN(6),
+	IMX8QXP_ADC_CHAN(7),
+};
+
+static void imx8qxp_adc_feature_prepare(struct imx8qxp_adc *adc)
+{
+	u32 i;
+
+	adc->trigger_id = 0;
+	adc->cmd_id = 0;
+	adc->channel_id = 0;
+
+	for (i = 0; i < MAX_CMD + 1; i++) {
+		adc->adc_cmd_l[i].scale = 1;
+		adc->adc_cmd_l[i].mode = 0;
+		adc->adc_cmd_l[i].diff = 0;
+		adc->adc_cmd_l[i].absel = 0;
+		adc->adc_cmd_l[i].adch = 0;
+		adc->adc_cmd_h[i].next = 0;
+		adc->adc_cmd_h[i].loop = 0;
+		adc->adc_cmd_h[i].avgs = 0;
+		adc->adc_cmd_h[i].sts = 0;
+		adc->adc_cmd_h[i].lwi = 0;
+		adc->adc_cmd_h[i].cmpen = 0;
+	}
+
+	for (i = 0; i < MAX_TRIG; i++) {
+		adc->adc_trigger_ctrl[i].tcmd = 0;
+		adc->adc_trigger_ctrl[i].tdly = 0;
+		adc->adc_trigger_ctrl[i].tpri = 0;
+		adc->adc_trigger_ctrl[i].hten = 0;
+	}
+
+	adc->adc_cfg.pwren = 0;
+	adc->adc_cfg.pudly = 0;
+	adc->adc_cfg.refsel = 0;
+	adc->adc_cfg.pwrsel = 0;
+	adc->adc_cfg.tprictrl = 0;
+}
+
+static void imx8qxp_adc_reset(struct imx8qxp_adc *adc)
+{
+	u32 ctrl;
+
+	/*software reset, need to clear the set bit*/
+	ctrl = readl(adc->regs + ADC_CTRL);
+	ctrl |= 1 << ADC_CTRL_SOFTWARE_RESET_SHIFT;
+	writel(ctrl, adc->regs + ADC_CTRL);
+	udelay(10);
+	ctrl &= ~(1 << ADC_CTRL_SOFTWARE_RESET_SHIFT);
+	writel(ctrl, adc->regs + ADC_CTRL);
+
+	/* reset the fifo */
+	ctrl |= 1 << ADC_CTRL_FIFO_RESET_SHIFT;
+	writel(ctrl, adc->regs + ADC_CTRL);
+}
+
+static void imx8qxp_adc_reg_config(struct imx8qxp_adc *adc)
+{
+	u32 adc_cfg, adc_tctrl, adc_cmdl, adc_cmdh;
+	u32 t_id, c_id;
+
+	adc_cfg = adc->adc_cfg.pwren << ADC_CFG_PWREN_SHIFT |
+		  adc->adc_cfg.pudly << ADC_CFG_PUDLY_SHIFT |
+		  adc->adc_cfg.refsel << ADC_CFG_REFSEL_SHIFT |
+		  adc->adc_cfg.pwrsel << ADC_CFG_PWRSEL_SHIFT |
+		  adc->adc_cfg.tprictrl << ADC_CFG_TPRICTRL_SHIFT;
+	writel(adc_cfg, adc->regs + ADC_CFG);
+
+	t_id = adc->trigger_id;
+	adc_tctrl = adc->adc_trigger_ctrl[t_id].tcmd << ADC_TCTRL_TCMD_SHIFT |
+		    adc->adc_trigger_ctrl[t_id].tdly << ADC_TCTRL_TDLY_SHIFT |
+		    adc->adc_trigger_ctrl[t_id].tpri << ADC_TCTRL_TPRI_SHIFT |
+		    adc->adc_trigger_ctrl[t_id].hten << ADC_TCTRL_HTEN_SHIFT;
+	writel(adc_tctrl, adc->regs + ADC_TCTRL(t_id));
+
+	c_id = adc->cmd_id - 1;
+	adc_cmdl = adc->adc_cmd_l[c_id].scale << ADC_CMDL_CSCALE_SHIFT |
+		   adc->adc_cmd_l[c_id].mode << ADC_CMDL_MODE_SHIFT |
+		   adc->adc_cmd_l[c_id].diff << ADC_CMDL_DIFF_SHIFT |
+		   adc->adc_cmd_l[c_id].absel << ADC_CMDL_ABSEL_SHIFT |
+		   adc->adc_cmd_l[c_id].adch << ADC_CMDL_ADCH_SHIFT;
+	writel(adc_cmdl, adc->regs + ADC_CMDL(c_id));
+
+	adc_cmdh = adc->adc_cmd_h[c_id].next << ADC_CMDH_NEXT_SHIFT |
+		   adc->adc_cmd_h[c_id].loop << ADC_CMDH_LOOP_SHIFT |
+		   adc->adc_cmd_h[c_id].avgs << ADC_CMDH_AVGS_SHIFT |
+		   adc->adc_cmd_h[c_id].sts << ADC_CMDH_STS_SHIFT |
+		   adc->adc_cmd_h[c_id].lwi << ADC_CMDH_LWI_SHIFT |
+		   adc->adc_cmd_h[c_id].cmpen << ADC_CMDH_CMPEN_SHIFT;
+	writel(adc_cmdh, adc->regs + ADC_CMDH(c_id));
+}
+
+static void imx8qxp_adc_mode_config(struct imx8qxp_adc *adc)
+{
+	u32 cmd_id, trigger_id, channel_id;
+
+	channel_id = adc->channel_id;
+	cmd_id = adc->cmd_id - 1;
+	trigger_id = adc->trigger_id;
+
+	/* config the cmd */
+	adc->adc_cmd_l[cmd_id].scale = ADC_CMDL_CHANNEL_SCALE_FULL;
+	adc->adc_cmd_l[cmd_id].mode = ADC_CMDL_STANDARD_RESOLUTION;
+	adc->adc_cmd_l[cmd_id].diff = ADC_CMDL_MODE_SINGLE;
+	adc->adc_cmd_l[cmd_id].absel = ADC_CMDL_SEL_A_A_B_CHANNEL;
+	adc->adc_cmd_l[cmd_id].adch = channel_id;
+
+	adc->adc_cmd_h[cmd_id].next = 0;
+	adc->adc_cmd_h[cmd_id].loop = 0;
+	adc->adc_cmd_h[cmd_id].avgs = 7;
+	adc->adc_cmd_h[cmd_id].sts = 0;
+	adc->adc_cmd_h[cmd_id].lwi = ADC_CMDH_LWI_INCREMENT_DISABLE;
+	adc->adc_cmd_h[cmd_id].cmpen = ADC_CMDH_CMPEN_DISABLE;
+
+	/* config the trigger control */
+	adc->adc_trigger_ctrl[trigger_id].tcmd = adc->cmd_id;
+	adc->adc_trigger_ctrl[trigger_id].tdly = 0;
+	adc->adc_trigger_ctrl[trigger_id].tpri = ADC_TCTRL_TPRI_PRIORITY_HIGH;
+	adc->adc_trigger_ctrl[trigger_id].hten = ADC_TCTRL_HTEN_HARDWARE_TIRGGER_DISABLE;
+
+	/* ADC configuration */
+	adc->adc_cfg.pwren = 1;
+	adc->adc_cfg.pudly = 0x80;
+	adc->adc_cfg.refsel = 0;
+	adc->adc_cfg.pwrsel = 3;
+	adc->adc_cfg.tprictrl = 0;
+
+	imx8qxp_adc_reg_config(adc);
+}
+
+static void imx8qxp_adc_fifo_config(struct imx8qxp_adc *adc)
+{
+	u32 fifo_ctrl, interrupt_en;
+
+	fifo_ctrl = readl(adc->regs + ADC_FCTRL);
+	fifo_ctrl &= ~ADC_FCTRL_FWMARK_MASK;
+	/* set the watermark level to 1 */
+	fifo_ctrl |= 0 << ADC_FCTRL_FWMARK_SHIFT;
+	writel(fifo_ctrl, adc->regs + ADC_FCTRL);
+
+	/* FIFO Watermark Interrupt Enable */
+	interrupt_en = readl(adc->regs + ADC_IE);
+	interrupt_en |= 1 << ADC_IE_FWMIE_SHIFT;
+	writel(interrupt_en, adc->regs + ADC_IE);
+}
+
+static void imx8qxp_adc_disable(struct imx8qxp_adc *adc)
+{
+	u32 ctrl;
+
+	ctrl = readl(adc->regs + ADC_CTRL) & ~(1 << ADC_CTRL_ADC_ENABLE);
+	writel(ctrl, adc->regs + ADC_CTRL);
+}
+
+static int imx8qxp_adc_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
+				int *val, int *val2, long mask)
+{
+	struct imx8qxp_adc *adc = iio_priv(indio_dev);
+	struct device *dev = adc->dev;
+
+	u32 channel;
+	u32 ctrl;
+	long ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		pm_runtime_get_sync(dev);
+
+		mutex_lock(&indio_dev->mlock);
+		reinit_completion(&adc->completion);
+
+		channel = chan->channel & 0x07;
+		adc->channel_id = channel;
+		adc->cmd_id = 1;
+		adc->trigger_id = 0;
+		imx8qxp_adc_mode_config(adc);
+
+		imx8qxp_adc_fifo_config(adc);
+
+		/* adc enable */
+		ctrl = readl(adc->regs + ADC_CTRL) | (1 << ADC_CTRL_ADC_ENABLE);
+		writel(ctrl, adc->regs + ADC_CTRL);
+		/* adc start */
+		writel(1 << adc->trigger_id, adc->regs + ADC_SWTRIG);
+
+		ret = wait_for_completion_interruptible_timeout
+				(&adc->completion, ADC_TIMEOUT);
+
+		pm_runtime_mark_last_busy(dev);
+		pm_runtime_put_sync_autosuspend(dev);
+
+		if (ret == 0) {
+			mutex_unlock(&indio_dev->mlock);
+			return -ETIMEDOUT;
+		}
+		if (ret < 0) {
+			mutex_unlock(&indio_dev->mlock);
+			return ret;
+		}
+
+		*val = adc->value;
+		mutex_unlock(&indio_dev->mlock);
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+		adc->vref_uv = regulator_get_voltage(adc->vref);
+		*val = adc->vref_uv / 1000;
+		*val2 = 12;
+		return IIO_VAL_FRACTIONAL_LOG2;
+
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*val = clk_get_rate(adc->clk) / 3;
+		return IIO_VAL_INT;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static irqreturn_t imx8qxp_adc_isr(int irq, void *dev_id)
+{
+	struct imx8qxp_adc *adc = (struct imx8qxp_adc *)dev_id;
+
+	u32 fifo_count;
+
+	fifo_count = readl(adc->regs + ADC_FCTRL)
+			& ADC_FCTRL_FCOUNT_MASK;
+
+	if (fifo_count) {
+		adc->value = (readl(adc->regs + ADC_RESFIFO) & 0xffff) >> 3;
+		complete(&adc->completion);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int imx8qxp_adc_reg_access(struct iio_dev *indio_dev, unsigned int reg,
+				  unsigned int writeval, unsigned int *readval)
+{
+	struct imx8qxp_adc *adc = iio_priv(indio_dev);
+	struct device *dev = adc->dev;
+
+	if (!readval || reg % 4 || reg > ADC_TST)
+		return -EINVAL;
+
+	pm_runtime_get_sync(dev);
+
+	*readval = readl(adc->regs + reg);
+
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_sync_autosuspend(dev);
+
+	return 0;
+}
+
+static const struct iio_info imx8qxp_adc_iio_info = {
+	.read_raw = &imx8qxp_adc_read_raw,
+	.debugfs_reg_access = &imx8qxp_adc_reg_access,
+};
+
 static int imx8qxp_adc_probe(struct platform_device *pdev)
 {
+	struct imx8qxp_adc *adc;
+	struct iio_dev *indio_dev;
+	struct device *dev = &pdev->dev;
+	int irq;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*adc));
+	if (!indio_dev) {
+		dev_err(dev, "Failed allocating iio device\n");
+		return -ENOMEM;
+	}
+
+	adc = iio_priv(indio_dev);
+	adc->dev = dev;
+
+	adc->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(adc->regs))
+		return PTR_ERR(adc->regs);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	adc->clk = devm_clk_get(dev, "per");
+	if (IS_ERR(adc->clk)) {
+		ret = PTR_ERR(adc->clk);
+		dev_err(dev, "Failed getting clock, err = %d\n", ret);
+		return ret;
+	}
+
+	adc->ipg_clk = devm_clk_get(dev, "ipg");
+	if (IS_ERR(adc->ipg_clk)) {
+		ret = PTR_ERR(adc->ipg_clk);
+		dev_err(dev, "Failed getting clock, err = %d\n", ret);
+		return ret;
+	}
+
+	adc->vref = devm_regulator_get(dev, "vref");
+	if (IS_ERR(adc->vref)) {
+		ret = PTR_ERR(adc->vref);
+		dev_err(dev,
+			"Failed getting reference voltage, err = %d\n", ret);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, indio_dev);
+
+	init_completion(&adc->completion);
+
+	indio_dev->name = dev_name(dev);
+	indio_dev->info = &imx8qxp_adc_iio_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = imx8qxp_adc_iio_channels;
+	indio_dev->num_channels = ARRAY_SIZE(imx8qxp_adc_iio_channels);
+
+	ret = devm_request_irq(dev, irq, imx8qxp_adc_isr, 0, dev_name(dev), adc);
+	if (ret < 0) {
+		dev_err(dev, "Failed requesting irq, irq = %d\n", irq);
+		return ret;
+	}
+
+	imx8qxp_adc_feature_prepare(adc);
+	imx8qxp_adc_reset(adc);
+
+	ret = iio_device_register(indio_dev);
+	if (ret) {
+		imx8qxp_adc_disable(adc);
+		dev_err(dev, "Couldn't register the device.\n");
+		return ret;
+	}
+
+	pm_runtime_set_active(dev);
+	pm_runtime_set_autosuspend_delay(dev, 50);
+	pm_runtime_use_autosuspend(dev);
+	pm_runtime_enable(dev);
+
 	return 0;
 }
 
 static int imx8qxp_adc_remove(struct platform_device *pdev)
 {
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct imx8qxp_adc *adc = iio_priv(indio_dev);
+	struct device *dev = adc->dev;
+
+	pm_runtime_get_sync(dev);
+
+	iio_device_unregister(indio_dev);
+
+	imx8qxp_adc_disable(adc);
+
+	pm_runtime_disable(dev);
+	pm_runtime_put_noidle(dev);
+
 	return 0;
 }
 
 static int imx8qxp_adc_runtime_suspend(struct device *dev)
 {
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct imx8qxp_adc *adc = iio_priv(indio_dev);
+
+	imx8qxp_adc_disable(adc);
+
+	clk_disable_unprepare(adc->clk);
+	clk_disable_unprepare(adc->ipg_clk);
+	regulator_disable(adc->vref);
+
 	return 0;
 }
 
 static int imx8qxp_adc_runtime_resume(struct device *dev)
 {
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct imx8qxp_adc *adc = iio_priv(indio_dev);
+	int ret;
+
+	ret = regulator_enable(adc->vref);
+	if (ret) {
+		dev_err(dev, "Can't enable adc reference top voltage, err = %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(adc->clk);
+	if (ret) {
+		dev_err(dev, "Could not prepare or enable clock.\n");
+		regulator_disable(adc->vref);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(adc->ipg_clk);
+	if (ret) {
+		dev_err(dev, "Could not prepare or enable clock.\n");
+		clk_disable_unprepare(adc->clk);
+		regulator_disable(adc->vref);
+		return ret;
+	}
+	imx8qxp_adc_reset(adc);
+
 	return 0;
 }
 
-- 
2.25.1