[PATCH 26/40] mfd: ti_am335x_tscadc: Introduce has_tsc

Miquel Raynal
2021-08-25T15:34:56Z

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>
---
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 30f53cdb41f8..a40091830cea 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);
}
@@ -139,11 +140,13 @@ 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);
- 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);
+ 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) {
@@ -218,15 +221,18 @@ 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;
- regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl);
+ tscadc->ctrl = CNTRLREG_STEPID;
+ if (tscadc->data->has_tsc) {
+ tscadc->ctrl |= CNTRLREG_TSC_STEPCONFIGWRT;
+ regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl);
+ if (use_tsc) {
+ tscadc->ctrl |= CNTRLREG_TSC_ENB;
+ if (tscmag_wires == 5)
+ tscadc->ctrl |= CNTRLREG_TSC_5WIRE;
+ else
+ tscadc->ctrl |= CNTRLREG_TSC_4WIRE;
+ }

- if (use_tsc) {
- tscadc->ctrl |= CNTRLREG_TSC_ENB;
- if (tscmag_wires == 5)
- tscadc->ctrl |= CNTRLREG_TSC_5WIRE;
- else
- tscadc->ctrl |= CNTRLREG_TSC_4WIRE;
}

tscadc_idle_config(tscadc);
@@ -321,6 +327,7 @@ 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 d5e2ff8dc84a..082b2af94263 100644
--- a/include/linux/mfd/ti_am335x_tscadc.h
+++ b/include/linux/mfd/ti_am335x_tscadc.h
@@ -163,6 +163,7 @@
#define TSCADC_CELLS 2

struct ti_tscadc_data {
+ bool has_tsc;
char *name_tscmag;
char *compat_tscmag;
char *name_adc;
--
2.27.0