Merge tag 'iio-fixes-for-4.0a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23...

[linux-drm-fsl-dcu.git] / drivers / staging / iio / adc / mxs-lradc.c

diff --git a/drivers/staging/iio/adc/mxs-lradc.c b/drivers/staging/iio/adc/mxs-lradc.c
index 351339ccaad6715b6d6fdcebfe4a38cf5c2830e1..816174388f13347447c495700e3dad85e7c269db 100644 (file)
--- a/drivers/staging/iio/adc/mxs-lradc.c
+++ b/drivers/staging/iio/adc/mxs-lradc.c
@@ -453,7 +453,14 @@ static void mxs_lradc_setup_ts_channel(struct mxs_lradc *lradc, unsigned ch)
         */
        mxs_lradc_reg_clear(lradc, LRADC_CH_VALUE_MASK, LRADC_CH(ch));
 
-       /* prepare the delay/loop unit according to the oversampling count */
+       /*
+        * prepare the delay/loop unit according to the oversampling count
+        *
+        * from the datasheet:
+        * "The DELAY fields in HW_LRADC_DELAY0, HW_LRADC_DELAY1,
+        * HW_LRADC_DELAY2, and HW_LRADC_DELAY3 must be non-zero; otherwise,
+        * the LRADC will not trigger the delay group."
+        */
        mxs_lradc_reg_wrt(lradc, LRADC_DELAY_TRIGGER(1 << ch) |
                LRADC_DELAY_TRIGGER_DELAYS(0) |
                LRADC_DELAY_LOOP(lradc->over_sample_cnt - 1) |
@@ -1493,20 +1500,38 @@ static int mxs_lradc_probe_touchscreen(struct mxs_lradc *lradc,
                return -EINVAL;
        }
 
-       lradc->over_sample_cnt = 4;
-       ret = of_property_read_u32(lradc_node, "fsl,ave-ctrl", &adapt);
-       if (ret == 0)
+       if (of_property_read_u32(lradc_node, "fsl,ave-ctrl", &adapt)) {
+               lradc->over_sample_cnt = 4;
+       } else {
+               if (adapt < 1 || adapt > 32) {
+                       dev_err(lradc->dev, "Invalid sample count (%u)\n",
+                               adapt);
+                       return -EINVAL;
+               }
                lradc->over_sample_cnt = adapt;
+       }
 
-       lradc->over_sample_delay = 2;
-       ret = of_property_read_u32(lradc_node, "fsl,ave-delay", &adapt);
-       if (ret == 0)
+       if (of_property_read_u32(lradc_node, "fsl,ave-delay", &adapt)) {
+               lradc->over_sample_delay = 2;
+       } else {
+               if (adapt < 2 || adapt > LRADC_DELAY_DELAY_MASK + 1) {
+                       dev_err(lradc->dev, "Invalid sample delay (%u)\n",
+                               adapt);
+                       return -EINVAL;
+               }
                lradc->over_sample_delay = adapt;
+       }
 
-       lradc->settling_delay = 10;
-       ret = of_property_read_u32(lradc_node, "fsl,settling", &adapt);
-       if (ret == 0)
+       if (of_property_read_u32(lradc_node, "fsl,settling", &adapt)) {
+               lradc->settling_delay = 10;
+       } else {
+               if (adapt < 1 || adapt > LRADC_DELAY_DELAY_MASK) {
+                       dev_err(lradc->dev, "Invalid settling delay (%u)\n",
+                               adapt);
+                       return -EINVAL;
+               }
                lradc->settling_delay = adapt;
+       }
 
        return 0;
 }