MFD: ti_tscadc: Disable TSC config registers in adc mode

AFE Pen Ctrl and TouchScreen transistors enabling is not
required when only ADC mode is being used, so check for availability of
TSC driver before accessing control register.

Signed-off-by: Patil, Rachna <rachna@ti.com>
Acked-by: Vaibhav Hiremath <hvaibhav@ti.com>
Signed-off-by: Zubair Lutfullah <zubair.lutfullah@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index e0852ecbc76718f9f497fe4a2fe5d1f7e369325e..cd74d594c563693fb8f288a5bbe524c904c0d399 100644 (file)
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -204,13 +204,14 @@ static    int ti_tscadc_probe(struct platform_device *pdev)
 
        /* Set the control register bits */
        ctrl = CNTRLREG_STEPCONFIGWRT |
-                       CNTRLREG_TSCENB |
-                       CNTRLREG_STEPID |
-                       CNTRLREG_4WIRE;
+                       CNTRLREG_STEPID;
+       if (tsc_wires > 0)
+               ctrl |= CNTRLREG_4WIRE | CNTRLREG_TSCENB;
        tscadc_writel(tscadc, REG_CTRL, ctrl);
 
        /* Set register bits for Idle Config Mode */
-       tscadc_idle_config(tscadc);
+       if (tsc_wires > 0)
+               tscadc_idle_config(tscadc);
 
        /* Enable the TSC module enable bit */
        ctrl = tscadc_readl(tscadc, REG_CTRL);
@@ -290,10 +291,13 @@ static int tscadc_resume(struct device *dev)
        pm_runtime_get_sync(dev);
 
        /* context restore */
-       ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_TSCENB |
-                       CNTRLREG_STEPID | CNTRLREG_4WIRE;
+       ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_STEPID;
+       if (tscadc_dev->tsc_cell != -1)
+               ctrl |= CNTRLREG_TSCENB | CNTRLREG_4WIRE;
        tscadc_writel(tscadc_dev, REG_CTRL, ctrl);
-       tscadc_idle_config(tscadc_dev);
+
+       if (tscadc_dev->tsc_cell != -1)
+               tscadc_idle_config(tscadc_dev);
        am335x_tsc_se_update(tscadc_dev);
        restore = tscadc_readl(tscadc_dev, REG_CTRL);
        tscadc_writel(tscadc_dev, REG_CTRL,