The TSC part allows to specify the input lines. The IIO part assumes
that it usues always the last few, that means if IIO has adc-channels
set to 2 it will use channel 6 and 7. However it might make sense to use
only 6.
This patch changes the device property (which was introduced recently
and was never in an official release) in a way that the user can specify
which of the AIN lines should be used. In Addition to this, the name is
now AINx where x is the channel number i.e. for AIN6 we would have 6.
Prior this, it always started counting at 0 which is confusing. In
addition to this, it also checks for correct step number during reading
and does not rely on proper FIFO depth.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
.../bindings/input/touchscreen/ti-tsc-adc.txt | 5 +-
arch/arm/boot/dts/am335x-evm.dts | 2 +-
drivers/iio/adc/ti_am335x_adc.c | 59 +++++++++++++-------
drivers/mfd/ti_am335x_tscadc.c | 20 ++++++-
4 files changed, 60 insertions(+), 26 deletions(-)
diff --git a/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt b/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt
index 80e04e3..204c9cc 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt
+++ b/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt
@@ -25,7 +25,8 @@
AIN0 = 0, AIN1 = 1 and so on till AIN7 = 7.
XP = 0, XN = 1, YP = 2, YN = 3.
- child "adc"
- ti,adc-channels: Number of analog inputs available for ADC
+ ti,adc-channels: List of analog inputs available for ADC.
+ AIN0 = 0, AIN1 = 1 and so on till AIN7 = 7.
Example:
tscadc: tscadc@44e0d000 {
@@ -38,6 +39,6 @@
};
adc {
- ti,adc-channels = <4>;
+ ti,adc-channels = <4 5 6 7>;
};
}
diff --git a/arch/arm/boot/dts/am335x-evm.dts b/arch/arm/boot/dts/am335x-evm.dts
index 26fea97..0fa4c7f 100644
--- a/arch/arm/boot/dts/am335x-evm.dts
+++ b/arch/arm/boot/dts/am335x-evm.dts
@@ -255,6 +255,6 @@
};
adc {
- ti,adc-channels = <4>;
+ ti,adc-channels = <4 5 6 7>;
};
};
diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
index 2988840..df2de4c 100644
--- a/drivers/iio/adc/ti_am335x_adc.c
+++ b/drivers/iio/adc/ti_am335x_adc.c
@@ -33,6 +33,8 @@
struct tiadc_device {
struct ti_tscadc_dev *mfd_tscadc;
int channels;
+ u8 channel_line[8];
+ u8 channel_step[8];
char *buf;
struct iio_map *map;
};
@@ -55,7 +57,7 @@ static void tiadc_writel(struct tiadc_device *adc, unsigned int reg,
static void tiadc_step_config(struct tiadc_device *adc_dev)
{
unsigned int stepconfig;
- int i, channels = 0, steps;
+ int i, steps;
/*
* There are 16 configurable steps and 8 analog input
@@ -68,16 +70,18 @@ static void tiadc_step_config(struct tiadc_device *adc_dev)
*/
steps = TOTAL_STEPS - adc_dev->channels;
- channels = TOTAL_CHANNELS - adc_dev->channels;
-
stepconfig = STEPCONFIG_AVG_16 | STEPCONFIG_FIFO1;
- for (i = steps; i < TOTAL_STEPS; i++) {
- tiadc_writel(adc_dev, REG_STEPCONFIG(i),
- stepconfig | STEPCONFIG_INP(channels));
- tiadc_writel(adc_dev, REG_STEPDELAY(i),
+ for (i = 0; i < adc_dev->channels; i++) {
+ int chan;
+
+ chan = adc_dev->channel_line[i];
+ tiadc_writel(adc_dev, REG_STEPCONFIG(steps),
+ stepconfig | STEPCONFIG_INP(chan));
+ tiadc_writel(adc_dev, REG_STEPDELAY(steps),
STEPCONFIG_OPENDLY);
- channels++;
+ adc_dev->channel_step[i] = steps;
+ steps++;
}
tiadc_writel(adc_dev, REG_SE, STPENB_STEPENB);
}
@@ -101,11 +105,11 @@ static int tiadc_channel_init(struct iio_dev *indio_dev,
chan = chan_array;
for (i = 0; i < channels; i++, chan++, s += len + 1) {
- len = sprintf(s, "AIN%d", i);
+ len = sprintf(s, "AIN%d", adc_dev->channel_line[i]);
chan->type = IIO_VOLTAGE;
chan->indexed = 1;
- chan->channel = i;
+ chan->channel = adc_dev->channel_line[i];
chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
chan->datasheet_name = s;
chan->scan_type.sign = 'u';
@@ -155,7 +159,8 @@ static int tiadc_read_raw(struct iio_dev *indio_dev,
{
struct tiadc_device *adc_dev = iio_priv(indio_dev);
int i;
- unsigned int fifo1count, readx1;
+ unsigned int fifo1count, read;
+ u32 step = UINT_MAX;
/*
* When the sub-system is first enabled,
@@ -168,11 +173,20 @@ static int tiadc_read_raw(struct iio_dev *indio_dev,
* Hence we need to flush out this data.
*/
+ for (i = 0; i < ARRAY_SIZE(adc_dev->channel_step); i++) {
+ if (chan->channel == adc_dev->channel_line[i]) {
+ step = adc_dev->channel_step[i];
+ break;
+ }
+ }
+ if (WARN_ON_ONCE(step == UINT_MAX))
+ return -EINVAL;
+
fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
for (i = 0; i < fifo1count; i++) {
- readx1 = tiadc_readl(adc_dev, REG_FIFO1);
- if (i == chan->channel)
- *val = readx1 & 0xfff;
+ read = tiadc_readl(adc_dev, REG_FIFO1);
+ if (read >> 16 == step)
+ *val = read & 0xfff;
}
tiadc_writel(adc_dev, REG_SE, STPENB_STEPENB);
@@ -189,8 +203,11 @@ static int tiadc_probe(struct platform_device *pdev)
struct tiadc_device *adc_dev;
struct ti_tscadc_dev *tscadc_dev = pdev->dev.platform_data;
struct device_node *node = tscadc_dev->dev->of_node;
+ struct property *prop;
+ const __be32 *cur;
int err;
- u32 val32;
+ u32 val;
+ int channels = 0;
if (!node) {
dev_err(&pdev->dev, "Could not find valid DT data.\n");
@@ -212,11 +229,13 @@ static int tiadc_probe(struct platform_device *pdev)
err = -EINVAL;
goto err_free_device;
}
- err = of_property_read_u32(node,
- "ti,adc-channels", &val32);
- if (err < 0)
- goto err_free_device;
- adc_dev->channels = val32;
+
+ of_property_for_each_u32(node, "ti,adc-channels", prop, cur, val) {
+
+ adc_dev->channel_line[channels] = val;
+ channels++;
+ }
+ adc_dev->channels = channels;
indio_dev->dev.parent = &pdev->dev;
indio_dev->name = dev_name(&pdev->dev);
diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index 5e4076f..b228c41 100644
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -66,9 +66,13 @@ static int ti_tscadc_probe(struct platform_device *pdev)
struct clk *clk;
struct device_node *node = pdev->dev.of_node;
struct mfd_cell *cell;
+ struct property *prop;
+ const __be32 *cur;
+ u32 val;
int err, ctrl;
int clk_value, clock_rate;
int tsc_wires = 0, adc_channels = 0, total_channels;
+ int readouts = 0;
if (!pdev->dev.of_node) {
dev_err(&pdev->dev, "Could not find valid DT data.\n");
@@ -77,16 +81,26 @@ static int ti_tscadc_probe(struct platform_device *pdev)
node = of_get_child_by_name(pdev->dev.of_node, "tsc");
of_property_read_u32(node, "ti,wires", &tsc_wires);
+ of_property_read_u32(node, "ti,coordiante-readouts", &readouts);
node = of_get_child_by_name(pdev->dev.of_node, "adc");
- of_property_read_u32(node, "ti,adc-channels", &adc_channels);
-
+ of_property_for_each_u32(node, "ti,adc-channels", prop, cur, val) {
+ adc_channels++;
+ if (val > 7) {
+ dev_err(&pdev->dev, " PIN numbers are 0..7 (not %d)\n",
+ val);
+ return -EINVAL;
+ }
+ }
total_channels = tsc_wires + adc_channels;
-
if (total_channels > 8) {
dev_err(&pdev->dev, "Number of i/p channels more than 8\n");
return -EINVAL;
}
+ if (readouts * 2 + 2 + adc_channels > 16) {
+ dev_err(&pdev->dev, "Too many step configurations requested\n");
+ return -EINVAL;
+ }
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
--
1.7.10.4
--
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