input: ti_am33x_tsc: Step enable bits made configurable

Current code has hard coded value written to
step enable bits. Now the bits are updated based
on how many steps are needed to be configured got
from platform data.

The user needs to take care not to exceed
the count more than 16. While using ADC and TSC
one should take care to set this parameter correctly.

Sebastian added the common lock and moved the code, that manipulates the
steps, from into the mfd module.

Signed-off-by: Patil, Rachna <rachna@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

drivers/iio/adc/ti_am335x_adc.c

@@ -42,10 +42,20 @@ static void tiadc_writel(struct tiadc_device *adc, unsigned int reg,
 	writel(val, adc->mfd_tscadc->tscadc_base + reg);
 }
 
+static u32 get_adc_step_mask(struct tiadc_device *adc_dev)
+{
+	u32 step_en;
+
+	step_en = ((1 << adc_dev->channels) - 1);
+	step_en <<= TOTAL_STEPS - adc_dev->channels + 1;
+	return step_en;
+}
+
 static void tiadc_step_config(struct tiadc_device *adc_dev)
 {
 	unsigned int stepconfig;
 	int i, channels = 0, steps;
+	u32 step_en;
 
 	/*
 	 * There are 16 configurable steps and 8 analog input
@@ -69,7 +79,8 @@ static void tiadc_step_config(struct tiadc_device *adc_dev)
 				STEPCONFIG_OPENDLY);
 		channels++;
 	}
-	tiadc_writel(adc_dev, REG_SE, STPENB_STEPENB);
+	step_en = get_adc_step_mask(adc_dev);
+	am335x_tsc_se_set(adc_dev->mfd_tscadc, step_en);
 }
 
 static int tiadc_channel_init(struct iio_dev *indio_dev, int channels)
@@ -127,7 +138,7 @@ static int tiadc_read_raw(struct iio_dev *indio_dev,
 		if (i == chan->channel)
 			*val = readx1 & 0xfff;
 	}
-	tiadc_writel(adc_dev, REG_SE, STPENB_STEPENB);
+	am335x_tsc_se_update(adc_dev->mfd_tscadc);
 
 	return IIO_VAL_INT;
 }
@@ -191,10 +202,15 @@ err_ret:
 static int tiadc_remove(struct platform_device *pdev)
 {
 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct tiadc_device *adc_dev = iio_priv(indio_dev);
+	u32 step_en;
 
 	iio_device_unregister(indio_dev);
 	tiadc_channels_remove(indio_dev);
 
+	step_en = get_adc_step_mask(adc_dev);
+	am335x_tsc_se_clr(adc_dev->mfd_tscadc, step_en);
+
 	iio_device_free(indio_dev);
 
 	return 0;

drivers/input/touchscreen/ti_am335x_tsc.c

@@ -57,6 +57,7 @@ static void titsc_writel(struct titsc *tsc, unsigned int reg,
 static void titsc_step_config(struct titsc *ts_dev)
 {
 	unsigned int	config;
+	unsigned int	stepenable = 0;
 	int i, total_steps;
 
 	/* Configure the Step registers */
@@ -128,7 +129,9 @@ static void titsc_step_config(struct titsc *ts_dev)
 	titsc_writel(ts_dev, REG_STEPDELAY(total_steps + 2),
 			STEPCONFIG_OPENDLY);
 
-	titsc_writel(ts_dev, REG_SE, STPENB_STEPENB_TC);
+	/* The steps1 … end and bit 0 for TS_Charge */
+	stepenable = (1 << (total_steps + 2)) - 1;
+	am335x_tsc_se_set(ts_dev->mfd_tscadc, stepenable);
 }
 
 static void titsc_read_coordinates(struct titsc *ts_dev,
@@ -250,7 +253,7 @@ static irqreturn_t titsc_irq(int irq, void *dev)
 
 	titsc_writel(ts_dev, REG_IRQSTATUS, irqclr);
 
-	titsc_writel(ts_dev, REG_SE, STPENB_STEPENB_TC);
+	am335x_tsc_se_update(ts_dev->mfd_tscadc);
 	return IRQ_HANDLED;
 }
 
@@ -334,6 +337,11 @@ static int titsc_remove(struct platform_device *pdev)
 
 	free_irq(ts_dev->irq, ts_dev);
 
+	/* total steps followed by the enable mask */
+	steps = 2 * ts_dev->steps_to_configure + 2;
+	steps = (1 << steps) - 1;
+	am335x_tsc_se_clr(ts_dev->mfd_tscadc, steps);
+
 	input_unregister_device(ts_dev->input);
 
 	platform_set_drvdata(pdev, NULL);

drivers/mfd/ti_am335x_tscadc.c

@@ -48,6 +48,32 @@ static const struct regmap_config tscadc_regmap_config = {
 	.val_bits = 32,
 };
 
+void am335x_tsc_se_update(struct ti_tscadc_dev *tsadc)
+{
+	tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache);
+}
+EXPORT_SYMBOL_GPL(am335x_tsc_se_update);
+
+void am335x_tsc_se_set(struct ti_tscadc_dev *tsadc, u32 val)
+{
+	spin_lock(&tsadc->reg_lock);
+	tsadc->reg_se_cache |= val;
+	spin_unlock(&tsadc->reg_lock);
+
+	am335x_tsc_se_update(tsadc);
+}
+EXPORT_SYMBOL_GPL(am335x_tsc_se_set);
+
+void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val)
+{
+	spin_lock(&tsadc->reg_lock);
+	tsadc->reg_se_cache &= ~val;
+	spin_unlock(&tsadc->reg_lock);
+
+	am335x_tsc_se_update(tsadc);
+}
+EXPORT_SYMBOL_GPL(am335x_tsc_se_clr);
+
 static void tscadc_idle_config(struct ti_tscadc_dev *config)
 {
 	unsigned int idleconfig;
@@ -129,6 +155,7 @@ static	int ti_tscadc_probe(struct platform_device *pdev)
 		goto ret;
 	}
 
+	spin_lock_init(&tscadc->reg_lock);
 	pm_runtime_enable(&pdev->dev);
 	pm_runtime_get_sync(&pdev->dev);
 
@@ -239,7 +266,7 @@ static int tscadc_resume(struct device *dev)
 			CNTRLREG_STEPID | CNTRLREG_4WIRE;
 	tscadc_writel(tscadc_dev, REG_CTRL, ctrl);
 	tscadc_idle_config(tscadc_dev);
-	tscadc_writel(tscadc_dev, REG_SE, STPENB_STEPENB);
+	am335x_tsc_se_update(tscadc_dev);
 	restore = tscadc_readl(tscadc_dev, REG_CTRL);
 	tscadc_writel(tscadc_dev, REG_CTRL,
 			(restore | CNTRLREG_TSCSSENB));

include/linux/mfd/ti_am335x_tscadc.h

@@ -46,8 +46,6 @@
 /* Step Enable */
 #define STEPENB_MASK		(0x1FFFF << 0)
 #define STEPENB(val)		((val) << 0)
-#define STPENB_STEPENB		STEPENB(0x1FFFF)
-#define STPENB_STEPENB_TC	STEPENB(0x1FFF)
 
 /* IRQ enable */
 #define IRQENB_HW_PEN		BIT(0)
@@ -141,6 +139,8 @@ struct ti_tscadc_dev {
 	void __iomem *tscadc_base;
 	int irq;
 	struct mfd_cell cells[TSCADC_CELLS];
+	u32 reg_se_cache;
+	spinlock_t reg_lock;
 
 	/* tsc device */
 	struct titsc *tsc;
@@ -156,4 +156,8 @@ static inline struct ti_tscadc_dev *ti_tscadc_dev_get(struct platform_device *p)
 	return *tscadc_dev;
 }
 
+void am335x_tsc_se_update(struct ti_tscadc_dev *tsadc);
+void am335x_tsc_se_set(struct ti_tscadc_dev *tsadc, u32 val);
+void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val);
+
 #endif