iio: adc: remove event advertisment

The driver currently advertise events, however, the required callback
read_event_config is not implemented. This leads to a stack trace
when trying to read the even files in sysfs:
  Unable to handle kernel NULL pointer dereference at virtual address 00000000
  pgd = 80e04000
  [00000000] *pgd=10a57831, *pte=00000000, *ppte=00000000
  Internal error: Oops: 80000007 [#1] SMP ARM
  Modules linked in:
  CPU: 0 PID: 175 Comm: cat Not tainted 4.1.39-00001-g52349f183498 #41
  Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
  task: 80e4e800 ti: 80a38000 task.ti: 80a38000
  PC is at 0x0
  LR is at iio_ev_state_show+0x4c/0x70
  pc : [<00000000>]    lr : [<80613704>]    psr: a0070013
  sp : 80a39aa0  ip : 807f1a74  fp : 80a39ab4
  r10: 00000001  r9 : 8809d000  r8 : 80e74800
  r7 : 80da0c18  r6 : 807cae38  r5 : 00000000  r4 : 8809d000
  r3 : 00000002  r2 : 00000000  r1 : 807f1730  r0 : 80da0c00
  Flags: NzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
  Control: 10c5387d  Table: 10e0404a  DAC: 00000015
  Process cat (pid: 175, stack limit = 0x80a38210)

Signed-off-by: Stefan Agner <stefan.agner@toradex.com>
Acked-by: Max Krummenacher <max.krummenacher@toradex.com>
(cherry picked from commit b6798bb5050a786f7cdd2a47db8029fee74e36fe)

1 files changed, 28 insertions, 49 deletions

diff --git a/drivers/staging/iio/adc/stmpe-adc.c b/drivers/staging/iio/adc/stmpe-adc.c
index f23c1e92d5bb..2918b16d98e8 100644
--- a/drivers/staging/iio/adc/stmpe-adc.c
+++ b/drivers/staging/iio/adc/stmpe-adc.c
@@ -191,64 +191,41 @@ static const struct iio_info stmpe_adc_iio_info = {
 	.driver_module = THIS_MODULE,
 };
 
-
-static const struct iio_event_spec stmpe_adc_events[] = {
-	{
-		.type = IIO_EV_TYPE_THRESH,
-		.dir = IIO_EV_DIR_RISING,
-		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
-			BIT(IIO_EV_INFO_ENABLE),
-	}, {
-		.type = IIO_EV_TYPE_THRESH,
-		.dir = IIO_EV_DIR_FALLING,
-		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
-			BIT(IIO_EV_INFO_ENABLE),
-	},
-};
-
-#define STMPE_VOLTAGE_CHAN(_chan, ev_spec, num_ev_spec)			\
+#define STMPE_VOLTAGE_CHAN(_chan)					\
 {									\
 	.type = IIO_VOLTAGE,						\
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),		\
 	.indexed = 1,							\
 	.channel = _chan,						\
-	.event_spec = ev_spec,						\
-        .num_event_specs = num_ev_spec,					\
+}
+
+#define STMPE_TEMP_CHAN(_chan)						\
+{									\
+	.type = IIO_TEMP,						\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),		\
+	.indexed = 1,							\
+	.channel = _chan,						\
 }
 
 static const struct iio_chan_spec stmpe_adc_all_iio_channels[] = {
-	STMPE_VOLTAGE_CHAN(0, stmpe_adc_events, ARRAY_SIZE(stmpe_adc_events)),
-	STMPE_VOLTAGE_CHAN(1, stmpe_adc_events, ARRAY_SIZE(stmpe_adc_events)),
-	STMPE_VOLTAGE_CHAN(2, stmpe_adc_events, ARRAY_SIZE(stmpe_adc_events)),
-	STMPE_VOLTAGE_CHAN(3, stmpe_adc_events, ARRAY_SIZE(stmpe_adc_events)),
-	STMPE_VOLTAGE_CHAN(4, stmpe_adc_events, ARRAY_SIZE(stmpe_adc_events)),
-	STMPE_VOLTAGE_CHAN(5, stmpe_adc_events, ARRAY_SIZE(stmpe_adc_events)),
-	STMPE_VOLTAGE_CHAN(6, stmpe_adc_events, ARRAY_SIZE(stmpe_adc_events)),
-	STMPE_VOLTAGE_CHAN(7, stmpe_adc_events, ARRAY_SIZE(stmpe_adc_events)),
-	{
-		.type = IIO_TEMP,
-		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
-		.indexed = 1,
-		.channel = 8,
-		.event_spec = stmpe_adc_events,
-	        .num_event_specs = ARRAY_SIZE(stmpe_adc_events),
-	}
+	STMPE_VOLTAGE_CHAN(0),
+	STMPE_VOLTAGE_CHAN(1),
+	STMPE_VOLTAGE_CHAN(2),
+	STMPE_VOLTAGE_CHAN(3),
+	STMPE_VOLTAGE_CHAN(4),
+	STMPE_VOLTAGE_CHAN(5),
+	STMPE_VOLTAGE_CHAN(6),
+	STMPE_VOLTAGE_CHAN(7),
+	STMPE_TEMP_CHAN(8),
 };
 
 static const struct iio_chan_spec stmpe_adc_iio_channels[] = {
-	STMPE_VOLTAGE_CHAN(4, stmpe_adc_events, ARRAY_SIZE(stmpe_adc_events)),
-	STMPE_VOLTAGE_CHAN(5, stmpe_adc_events, ARRAY_SIZE(stmpe_adc_events)),
-	STMPE_VOLTAGE_CHAN(6, stmpe_adc_events, ARRAY_SIZE(stmpe_adc_events)),
-	STMPE_VOLTAGE_CHAN(7, stmpe_adc_events, ARRAY_SIZE(stmpe_adc_events)),
-	{
-		.type = IIO_TEMP,
-		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
-		.indexed = 1,
-		.channel = 8,
-		.event_spec = stmpe_adc_events,
-	        .num_event_specs = ARRAY_SIZE(stmpe_adc_events),
-	}
+	STMPE_VOLTAGE_CHAN(4),
+	STMPE_VOLTAGE_CHAN(5),
+	STMPE_VOLTAGE_CHAN(6),
+	STMPE_VOLTAGE_CHAN(7),
+	STMPE_TEMP_CHAN(8),
 };
 
 static int stmpe_adc_init_hw(struct stmpe_adc *adc)
@@ -360,11 +337,13 @@ static int stmpe_adc_probe(struct platform_device *pdev)
 	indio_dev->modes = INDIO_DIRECT_MODE;
 
 	/* Register TS-Channels only if they are available */
-	if (stmpe->blocks & STMPE_BLOCK_TOUCHSCREEN)
+	if (stmpe->blocks & STMPE_BLOCK_TOUCHSCREEN) {
 		indio_dev->channels = stmpe_adc_iio_channels;
-	else
+		indio_dev->num_channels = ARRAY_SIZE(stmpe_adc_iio_channels);
+	} else {
 		indio_dev->channels = stmpe_adc_all_iio_channels;
-	indio_dev->num_channels = ARRAY_SIZE(stmpe_adc_iio_channels);
+		indio_dev->num_channels = ARRAY_SIZE(stmpe_adc_all_iio_channels);
+	}
 
 	stmpe_adc_get_platform_info(pdev, info);