[PATCH 4/9] Staging/iio/adc/touchscreen/MXS: simplify register access

[Juergen Beisert <jbe@pengutronix.de>]

Replace the individual register access by a few shared access function to make the
code easier to read and in order to add the i.MX23 SoC in the next step.

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
CC: linux-arm-kernel@lists.infradead.org
CC: linux-input@vger.kernel.org
CC: devel@driverdev.osuosl.org
CC: Marek Vasut <marex@denx.de>
CC: Fabio Estevam <fabio.estevam@freescale.com>
CC: Jonathan Cameron <jic23@cam.ac.uk>
---
 drivers/staging/iio/adc/mxs-lradc.c | 204 +++++++++++++++++++++---------------
 1 file changed, 120 insertions(+), 84 deletions(-)

diff --git a/drivers/staging/iio/adc/mxs-lradc.c b/drivers/staging/iio/adc/mxs-lradc.c
index f2fb10a..dd47ec2 100644
--- a/drivers/staging/iio/adc/mxs-lradc.c
+++ b/drivers/staging/iio/adc/mxs-lradc.c
@@ -238,6 +238,56 @@ struct mxs_lradc {
 #define LRADC_RESOLUTION			12
 #define LRADC_SINGLE_SAMPLE_MASK		((1 << LRADC_RESOLUTION) - 1)
 
+static void mxs_lradc_reg_set(struct mxs_lradc *lradc, u32 val, u32 reg)
+{
+	writel(val, lradc->base + reg + STMP_OFFSET_REG_SET);
+}
+
+static void mxs_lradc_reg_clear(struct mxs_lradc *lradc, u32 val, u32 reg)
+{
+	writel(val, lradc->base + reg + STMP_OFFSET_REG_CLR);
+}
+
+static void mxs_lradc_reg_wrt(struct mxs_lradc *lradc, u32 val, u32 reg)
+{
+	writel(val, lradc->base + reg);
+}
+
+static u32 mxs_lradc_plate_mask(struct mxs_lradc *lradc)
+{
+	return LRADC_CTRL0_MX28_PLATE_MASK;
+}
+
+static u32 mxs_lradc_irq_en_mask(struct mxs_lradc *lradc)
+{
+	return LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK;
+}
+
+static u32 mxs_lradc_irq_mask(struct mxs_lradc *lradc)
+{
+	return LRADC_CTRL1_MX28_LRADC_IRQ_MASK;
+}
+
+static u32 mxs_lradc_touch_detect_bit(struct mxs_lradc *lradc)
+{
+	return LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE;
+}
+
+static u32 mxs_lradc_drive_x_plate(struct mxs_lradc *lradc)
+{
+	return LRADC_CTRL0_MX28_XPPSW | LRADC_CTRL0_MX28_XNNSW;
+}
+
+static u32 mxs_lradc_drive_y_plate(struct mxs_lradc *lradc)
+{
+	return LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_YNNSW;
+}
+
+static u32 mxs_lradc_drive_pressure(struct mxs_lradc *lradc)
+{
+	return LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_XNNSW;
+}
+
 /*
  * Raw I/O operations
  */
@@ -272,21 +322,19 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
 	 * Virtual channel 0 is always used here as the others are always not
 	 * used if doing raw sampling.
 	 */
-	writel(LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK,
-		lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
-	writel(0xff, lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
+	mxs_lradc_reg_clear(lradc, LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK,
+			LRADC_CTRL1);
+	mxs_lradc_reg_clear(lradc, 0xff, LRADC_CTRL0);
 
 	/* Clean the slot's previous content, then set new one. */
-	writel(LRADC_CTRL4_LRADCSELECT_MASK(0),
-		lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR);
-	writel(chan->channel, lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET);
+	mxs_lradc_reg_clear(lradc, LRADC_CTRL4_LRADCSELECT_MASK(0), LRADC_CTRL4);
+	mxs_lradc_reg_set(lradc, chan->channel, LRADC_CTRL4);
 
-	writel(0, lradc->base + LRADC_CH(0));
+	mxs_lradc_reg_wrt(lradc, 0, LRADC_CH(0));
 
 	/* Enable the IRQ and start sampling the channel. */
-	writel(LRADC_CTRL1_LRADC_IRQ_EN(0),
-		lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET);
-	writel(1 << 0, lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);
+	mxs_lradc_reg_set(lradc, LRADC_CTRL1_LRADC_IRQ_EN(0), LRADC_CTRL1);
+	mxs_lradc_reg_set(lradc, 1 << 0, LRADC_CTRL0);
 
 	/* Wait for completion on the channel, 1 second max. */
 	ret = wait_for_completion_killable_timeout(&lradc->completion, HZ);
@@ -300,8 +348,7 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
 	ret = IIO_VAL_INT;
 
 err:
-	writel(LRADC_CTRL1_LRADC_IRQ_EN(0),
-		lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
+	mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ_EN(0), LRADC_CTRL1);
 
 	mutex_unlock(&lradc->lock);
 
@@ -327,10 +374,9 @@ static int mxs_lradc_ts_touched(struct mxs_lradc *lradc)
 	uint32_t reg;
 
 	/* Enable touch detection. */
-	writel(LRADC_CTRL0_MX28_PLATE_MASK,
-		lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
-	writel(LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE,
-		lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);
+	mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
+	mxs_lradc_reg_set(lradc, mxs_lradc_touch_detect_bit(lradc),
+								LRADC_CTRL0);
 
 	msleep(LRADC_TS_SAMPLE_DELAY_MS);
 
@@ -375,32 +421,33 @@ static int32_t mxs_lradc_ts_sample(struct mxs_lradc *lradc,
 	 */
 	switch (plate) {
 	case LRADC_SAMPLE_X:
-		ctrl0 = LRADC_CTRL0_MX28_XPPSW | LRADC_CTRL0_MX28_XNNSW;
+		ctrl0 = mxs_lradc_drive_x_plate(lradc);
 		chan = 3;
 		break;
 	case LRADC_SAMPLE_Y:
-		ctrl0 = LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_YNNSW;
+		ctrl0 = mxs_lradc_drive_y_plate(lradc);
 		chan = 4;
 		break;
 	case LRADC_SAMPLE_PRESSURE:
-		ctrl0 = LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_XNNSW;
+		ctrl0 = mxs_lradc_drive_pressure(lradc);
 		chan = 5;
 		break;
 	}
 
 	if (change) {
-		writel(LRADC_CTRL0_MX28_PLATE_MASK,
-			lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
-		writel(ctrl0, lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);
-
-		writel(LRADC_CTRL4_LRADCSELECT_MASK(slot),
-			lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR);
-		writel(chan << LRADC_CTRL4_LRADCSELECT_OFFSET(slot),
-			lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET);
+		mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc),
+						LRADC_CTRL0);
+		mxs_lradc_reg_set(lradc, ctrl0, LRADC_CTRL0);
+
+		mxs_lradc_reg_clear(lradc, LRADC_CTRL4_LRADCSELECT_MASK(slot),
+						LRADC_CTRL4);
+		mxs_lradc_reg_set(lradc,
+				chan << LRADC_CTRL4_LRADCSELECT_OFFSET(slot),
+				LRADC_CTRL4);
 	}
 
-	writel(0xffffffff, lradc->base + LRADC_CH(slot) + STMP_OFFSET_REG_CLR);
-	writel(1 << slot, lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);
+	mxs_lradc_reg_clear(lradc, 0xffffffff, LRADC_CH(slot));
+	mxs_lradc_reg_set(lradc, 1 << slot, LRADC_CTRL0);
 
 	delay = jiffies + msecs_to_jiffies(LRADC_TS_SAMPLE_DELAY_MS);
 	do {
@@ -410,8 +457,7 @@ static int32_t mxs_lradc_ts_sample(struct mxs_lradc *lradc,
 			break;
 	} while (time_before(jiff, delay));
 
-	writel(LRADC_CTRL1_LRADC_IRQ(slot),
-		lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
+	mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ(slot), LRADC_CTRL1);
 
 	if (time_after_eq(jiff, delay))
 		return -ETIMEDOUT;
@@ -450,8 +496,8 @@ static void mxs_lradc_ts_work(struct work_struct *ts_work)
 
 	while (mxs_lradc_ts_touched(lradc)) {
 		/* Disable touch detector so we can sample the touchscreen. */
-		writel(LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE,
-			lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
+		mxs_lradc_reg_clear(lradc, mxs_lradc_touch_detect_bit(lradc),
+						LRADC_CTRL0);
 
 		if (likely(valid)) {
 			input_report_abs(lradc->ts_input, ABS_X, val_x);
@@ -485,10 +531,8 @@ static void mxs_lradc_ts_work(struct work_struct *ts_work)
 		return;
 
 	/* Restart the touchscreen interrupts. */
-	writel(LRADC_CTRL1_TOUCH_DETECT_IRQ,
-		lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
-	writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
-		lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET);
+	mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ, LRADC_CTRL1);
+	mxs_lradc_reg_set(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
 }
 
 static int mxs_lradc_ts_open(struct input_dev *dev)
@@ -499,12 +543,11 @@ static int mxs_lradc_ts_open(struct input_dev *dev)
 	lradc->stop_touchscreen = false;
 
 	/* Enable the touch-detect circuitry. */
-	writel(LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE,
-		lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);
+	mxs_lradc_reg_set(lradc, mxs_lradc_touch_detect_bit(lradc),
+						LRADC_CTRL0);
 
 	/* Enable the touch-detect IRQ. */
-	writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
-		lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET);
+	mxs_lradc_reg_set(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
 
 	return 0;
 }
@@ -521,12 +564,11 @@ static void mxs_lradc_ts_close(struct input_dev *dev)
 	cancel_work_sync(&lradc->ts_work);
 
 	/* Disable touchscreen touch-detect IRQ. */
-	writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
-		lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
+	mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
+						LRADC_CTRL1);
 
 	/* Power-down touchscreen touch-detect circuitry. */
-	writel(LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE,
-		lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
+	mxs_lradc_reg_clear(lradc, mxs_lradc_touch_detect_bit(lradc), LRADC_CTRL0);
 }
 
 static int mxs_lradc_ts_register(struct mxs_lradc *lradc)
@@ -589,7 +631,7 @@ static irqreturn_t mxs_lradc_handle_irq(int irq, void *data)
 		LRADC_CTRL1_TOUCH_DETECT_IRQ_EN |
 		LRADC_CTRL1_TOUCH_DETECT_IRQ;
 
-	if (!(reg & LRADC_CTRL1_MX28_LRADC_IRQ_MASK))
+	if (!(reg & mxs_lradc_irq_mask(lradc)))
 		return IRQ_NONE;
 
 	/*
@@ -598,8 +640,7 @@ static irqreturn_t mxs_lradc_handle_irq(int irq, void *data)
 	 * it ASAP
 	 */
 	if (reg & LRADC_CTRL1_TOUCH_DETECT_IRQ) {
-		writel(ts_irq_mask,
-			lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
+		mxs_lradc_reg_clear(lradc, ts_irq_mask, LRADC_CTRL1);
 		if (!lradc->stop_touchscreen)
 			schedule_work(&lradc->ts_work);
 	}
@@ -609,8 +650,7 @@ static irqreturn_t mxs_lradc_handle_irq(int irq, void *data)
 	else if (reg & LRADC_CTRL1_LRADC_IRQ(0))
 		complete(&lradc->completion);
 
-	writel(reg & LRADC_CTRL1_MX28_LRADC_IRQ_MASK,
-		lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
+	mxs_lradc_reg_clear(lradc, reg & mxs_lradc_irq_mask(lradc), LRADC_CTRL1);
 
 	return IRQ_HANDLED;
 }
@@ -629,7 +669,7 @@ static irqreturn_t mxs_lradc_trigger_handler(int irq, void *p)
 
 	for_each_set_bit(i, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) {
 		lradc->buffer[j] = readl(lradc->base + LRADC_CH(j));
-		writel(chan_value, lradc->base + LRADC_CH(j));
+		mxs_lradc_reg_wrt(lradc, chan_value, LRADC_CH(j));
 		lradc->buffer[j] &= LRADC_CH_VALUE_MASK;
 		lradc->buffer[j] /= LRADC_DELAY_TIMER_LOOP;
 		j++;
@@ -654,7 +694,7 @@ static int mxs_lradc_configure_trigger(struct iio_trigger *trig, bool state)
 	struct mxs_lradc *lradc = iio_priv(iio);
 	const uint32_t st = state ? STMP_OFFSET_REG_SET : STMP_OFFSET_REG_CLR;
 
-	writel(LRADC_DELAY_KICK, lradc->base + LRADC_DELAY(0) + st);
+	mxs_lradc_reg_wrt(lradc, LRADC_DELAY_KICK, LRADC_DELAY(0) + st);
 
 	return 0;
 }
@@ -730,29 +770,26 @@ static int mxs_lradc_buffer_preenable(struct iio_dev *iio)
 	if (ret < 0)
 		goto err_buf;
 
-	writel(LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK,
-		lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
-	writel(0xff, lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
+	mxs_lradc_reg_clear(lradc, LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK,
+							LRADC_CTRL1);
+	mxs_lradc_reg_clear(lradc, 0xff, LRADC_CTRL0);
 
 	for_each_set_bit(chan, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) {
 		ctrl4_set |= chan << LRADC_CTRL4_LRADCSELECT_OFFSET(ofs);
 		ctrl4_clr |= LRADC_CTRL4_LRADCSELECT_MASK(ofs);
 		ctrl1_irq |= LRADC_CTRL1_LRADC_IRQ_EN(ofs);
-		writel(chan_value, lradc->base + LRADC_CH(ofs));
+		mxs_lradc_reg_wrt(lradc, chan_value, LRADC_CH(ofs));
 		bitmap_set(&enable, ofs, 1);
 		ofs++;
 	}
 
-	writel(LRADC_DELAY_TRIGGER_LRADCS_MASK | LRADC_DELAY_KICK,
-		lradc->base + LRADC_DELAY(0) + STMP_OFFSET_REG_CLR);
-
-	writel(ctrl4_clr, lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR);
-	writel(ctrl4_set, lradc->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET);
-
-	writel(ctrl1_irq, lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET);
-
-	writel(enable << LRADC_DELAY_TRIGGER_LRADCS_OFFSET,
-		lradc->base + LRADC_DELAY(0) + STMP_OFFSET_REG_SET);
+	mxs_lradc_reg_clear(lradc, LRADC_DELAY_TRIGGER_LRADCS_MASK |
+					LRADC_DELAY_KICK, LRADC_DELAY(0));
+	mxs_lradc_reg_clear(lradc, ctrl4_clr, LRADC_CTRL4);
+	mxs_lradc_reg_set(lradc, ctrl4_set, LRADC_CTRL4);
+	mxs_lradc_reg_set(lradc, ctrl1_irq, LRADC_CTRL1);
+	mxs_lradc_reg_set(lradc, enable << LRADC_DELAY_TRIGGER_LRADCS_OFFSET,
+					LRADC_DELAY(0));
 
 	return 0;
 
@@ -767,12 +804,12 @@ static int mxs_lradc_buffer_postdisable(struct iio_dev *iio)
 {
 	struct mxs_lradc *lradc = iio_priv(iio);
 
-	writel(LRADC_DELAY_TRIGGER_LRADCS_MASK | LRADC_DELAY_KICK,
-		lradc->base + LRADC_DELAY(0) + STMP_OFFSET_REG_CLR);
+	mxs_lradc_reg_clear(lradc, LRADC_DELAY_TRIGGER_LRADCS_MASK |
+					LRADC_DELAY_KICK, LRADC_DELAY(0));
 
-	writel(0xff, lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
-	writel(LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK,
-		lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
+	mxs_lradc_reg_clear(lradc, 0xff, LRADC_CTRL0);
+	mxs_lradc_reg_clear(lradc, LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK,
+					LRADC_CTRL1);
 
 	kfree(lradc->buffer);
 	mutex_unlock(&lradc->lock);
@@ -867,24 +904,24 @@ static int mxs_lradc_hw_init(struct mxs_lradc *lradc)
 		return ret;
 
 	/* Configure DELAY CHANNEL 0 for generic ADC sampling. */
-	writel(adc_cfg, lradc->base + LRADC_DELAY(0));
+	mxs_lradc_reg_wrt(lradc, adc_cfg, LRADC_DELAY(0));
 
 	/* Disable remaining DELAY CHANNELs */
-	writel(0, lradc->base + LRADC_DELAY(1));
-	writel(0, lradc->base + LRADC_DELAY(2));
-	writel(0, lradc->base + LRADC_DELAY(3));
+	mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(1));
+	mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(2));
+	mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(3));
 
 	/* Configure the touchscreen type */
-	writel(LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
-		lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
+	mxs_lradc_reg_clear(lradc, LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
+							LRADC_CTRL0);
 
-	if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_5WIRE) {
-		writel(LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
-			lradc->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);
+	if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_5WIRE)
+		mxs_lradc_reg_set(lradc, LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
+				LRADC_CTRL0);
 	}
 
 	/* Start internal temperature sensing. */
-	writel(0, lradc->base + LRADC_CTRL2);
+	mxs_lradc_reg_wrt(lradc, 0, LRADC_CTRL2);
 
 	return 0;
 }
@@ -893,11 +930,10 @@ static void mxs_lradc_hw_stop(struct mxs_lradc *lradc)
 {
 	int i;
 
-	writel(LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK,
-		lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
+	mxs_lradc_reg_clear(lradc, mxs_lradc_irq_en_mask(lradc), LRADC_CTRL1);
 
 	for (i = 0; i < LRADC_MAX_DELAY_CHANS; i++)
-		writel(0, lradc->base + LRADC_DELAY(i));
+		mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(i));
 }
 
 static const struct of_device_id mxs_lradc_dt_ids[] = {
-- 
1.8.4.rc3