mfd: ti_am335x_tscadc: Add a boolean to clarify the presence of a touchscreen

Just checking the number of wires will soon not be enough, add a boolean
to indicate the actual use or not of the touchscreen.

Certain checks only make sense when there is a touchscreen wired. Make
these checks explicitly depend on the presence of the touchscreen.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-35-miquel.raynal@bootlin.com

diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index 9699fe6ca7ebd84ebf2edb63380a1772690c1c2b..f7cfe2016bbcc06c5c88f253a55e9c12b6a4cc8f 100644 (file)
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -120,6 +120,7 @@ static      int ti_tscadc_probe(struct platform_device *pdev)
        struct mfd_cell *cell;
        struct property *prop;
        const __be32 *cur;
+       bool use_tsc = false;
        u32 val;
        int err;
        int tscmag_wires = 0, adc_channels = 0, cell_idx = 0, total_channels;
@@ -143,6 +144,8 @@ static      int ti_tscadc_probe(struct platform_device *pdev)
        of_property_read_u32(node, "ti,wires", &tscmag_wires);
        of_property_read_u32(node, "ti,coordiante-readouts", &readouts);
        of_node_put(node);
+       if (tscmag_wires)
+               use_tsc = true;
 
        node = of_get_child_by_name(pdev->dev.of_node, "adc");
        of_property_for_each_u32(node, "ti,adc-channels", prop, cur, val) {
@@ -168,7 +171,7 @@ static      int ti_tscadc_probe(struct platform_device *pdev)
                return -EINVAL;
        }
 
-       if (readouts * 2 + 2 + adc_channels > 16) {
+       if (use_tsc && (readouts * 2 + 2 + adc_channels > 16)) {
                dev_err(&pdev->dev, "Too many step configurations requested\n");
                return -EINVAL;
        }
@@ -223,7 +226,7 @@ static      int ti_tscadc_probe(struct platform_device *pdev)
         * added manually when timely.
         */
        tscadc->ctrl = CNTRLREG_TSC_STEPCONFIGWRT | CNTRLREG_STEPID;
-       if (tscmag_wires > 0) {
+       if (use_tsc) {
                tscadc->ctrl |= CNTRLREG_TSC_ENB;
                if (tscmag_wires == 5)
                        tscadc->ctrl |= CNTRLREG_TSC_5WIRE;