Thread (77 messages) 77 messages, 4 authors, 2021-09-19

[PATCH v2 32/46] mfd: ti_am335x_tscadc: Introduce has_tsc

From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: 2021-09-02 21:52:58
Also in: linux-devicetree, linux-iio, linux-omap
Subsystem: multifunction devices (mfd), the rest · Maintainers: Lee Jones, Linus Torvalds

One way of knowing which hardware we are dealing with is to check its
compatible. When this must be done at several places, it's best to use a
proper boolean for that. ->has_tsc indicates if there is a touchscreen
controller available (meaning it's a am33xx-like ADC) or not but does
not indicate if it is actually used (that is the purpose of the use_tsc
boolean in the probe).

Introducing this boolean helps making a difference in the code between
what is generic to both types of ADCs and what is specific to the am33xx
hardware before introducing support for the am437x hardware.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 drivers/mfd/ti_am335x_tscadc.c       | 37 +++++++++++++++++-----------
 include/linux/mfd/ti_am335x_tscadc.h |  1 +
 2 files changed, 23 insertions(+), 15 deletions(-)
diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index cfdef833dffb..29ada9da8826 100644
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -105,8 +105,9 @@ static void tscadc_idle_config(struct ti_tscadc_dev *tscadc)
 {
 	unsigned int idleconfig;
 
-	idleconfig = STEPCONFIG_YNN | STEPCONFIG_INM_ADCREFM |
-			STEPCONFIG_INP_ADCREFM | STEPCONFIG_YPN;
+	idleconfig = STEPCONFIG_INM_ADCREFM | STEPCONFIG_INP_ADCREFM;
+	if (tscadc->data->has_tsc)
+		idleconfig |= STEPCONFIG_YNN | STEPCONFIG_YPN;
 
 	regmap_write(tscadc->regmap, REG_IDLECONFIG, idleconfig);
 }
@@ -140,12 +141,14 @@ static	int ti_tscadc_probe(struct platform_device *pdev)
 
 	tscadc->data = of_device_get_match_data(&pdev->dev);
 
-	node = of_get_child_by_name(pdev->dev.of_node, "tsc");
-	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;
+	if (tscadc->data->has_tsc) {
+		node = of_get_child_by_name(pdev->dev.of_node, "tsc");
+		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) {
@@ -223,13 +226,16 @@ static	int ti_tscadc_probe(struct platform_device *pdev)
 	regmap_write(tscadc->regmap, REG_CLKDIV, tscadc->clk_div);
 
 	/* Set the control register bits */
-	tscadc->ctrl = CNTRLREG_TSC_STEPCONFIGWRT | CNTRLREG_STEPID;
-	if (use_tsc) {
-		tscadc->ctrl |= CNTRLREG_TSC_ENB;
-		if (tscmag_wires == 5)
-			tscadc->ctrl |= CNTRLREG_TSC_5WIRE;
-		else
-			tscadc->ctrl |= CNTRLREG_TSC_4WIRE;
+	tscadc->ctrl = CNTRLREG_STEPID;
+	if (tscadc->data->has_tsc) {
+		tscadc->ctrl |= CNTRLREG_TSC_STEPCONFIGWRT;
+		if (use_tsc) {
+			tscadc->ctrl |= CNTRLREG_TSC_ENB;
+			if (tscmag_wires == 5)
+				tscadc->ctrl |= CNTRLREG_TSC_5WIRE;
+			else
+				tscadc->ctrl |= CNTRLREG_TSC_4WIRE;
+		}
 	}
 	regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl);
 
@@ -325,6 +331,7 @@ static int __maybe_unused tscadc_resume(struct device *dev)
 static SIMPLE_DEV_PM_OPS(tscadc_pm_ops, tscadc_suspend, tscadc_resume);
 
 static const struct ti_tscadc_data tscdata = {
+	.has_tsc = true,
 	.name_tscmag = "TI-am335x-tsc",
 	.compat_tscmag = "ti,am3359-tsc",
 	.name_adc = "TI-am335x-adc",
diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h
index 29d3195b0193..3dbdb827566c 100644
--- a/include/linux/mfd/ti_am335x_tscadc.h
+++ b/include/linux/mfd/ti_am335x_tscadc.h
@@ -156,6 +156,7 @@
 #define TSCADC_CELLS		2
 
 struct ti_tscadc_data {
+	bool has_tsc;
 	char *name_tscmag;
 	char *compat_tscmag;
 	char *name_adc;
-- 
2.27.0
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