staging: comedi: ni_tio: validate clock source

Refactor the functions that determine the clock source bits so that they
return -EINVAL if the clock source is invalid. Pass the errno back to
ni_tio_insn_config().

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/drivers/ni_tio.c b/drivers/staging/comedi/drivers/ni_tio.c
index e7209c1..564ec9b 100644 (file)
--- a/drivers/staging/comedi/drivers/ni_tio.c
+++ b/drivers/staging/comedi/drivers/ni_tio.c
@@ -608,7 +608,7 @@ int ni_tio_arm(struct ni_gpct *counter, bool arm, unsigned int start_trigger)
 }
 EXPORT_SYMBOL_GPL(ni_tio_arm);
 
-static unsigned int ni_660x_clk_src(unsigned int clock_source)
+static int ni_660x_clk_src(unsigned int clock_source, unsigned int *bits)
 {
        unsigned int clk_src = clock_source & NI_GPCT_CLOCK_SRC_SELECT_MASK;
        unsigned int ni_660x_clock;
@@ -653,14 +653,13 @@ static unsigned int ni_660x_clk_src(unsigned int clock_source)
                }
                if (i <= NI_660X_MAX_SRC_PIN)
                        break;
-               ni_660x_clock = 0;
-               BUG();
-               break;
+               return -EINVAL;
        }
-       return GI_SRC_SEL(ni_660x_clock);
+       *bits = GI_SRC_SEL(ni_660x_clock);
+       return 0;
 }
 
-static unsigned int ni_m_clk_src(unsigned int clock_source)
+static int ni_m_clk_src(unsigned int clock_source, unsigned int *bits)
 {
        unsigned int clk_src = clock_source & NI_GPCT_CLOCK_SRC_SELECT_MASK;
        unsigned int ni_m_series_clock;
@@ -711,13 +710,10 @@ static unsigned int ni_m_clk_src(unsigned int clock_source)
                }
                if (i <= NI_M_MAX_PFI_CHAN)
                        break;
-               pr_err("invalid clock source 0x%lx\n",
-                      (unsigned long)clock_source);
-               BUG();
-               ni_m_series_clock = 0;
-               break;
+               return -EINVAL;
        }
-       return GI_SRC_SEL(ni_m_series_clock);
+       *bits = GI_SRC_SEL(ni_m_series_clock);
+       return 0;
 };
 
 static void ni_tio_set_source_subselect(struct ni_gpct *counter,
@@ -755,18 +751,26 @@ static int ni_tio_set_clock_src(struct ni_gpct *counter,
        struct ni_gpct_device *counter_dev = counter->counter_dev;
        unsigned int cidx = counter->counter_index;
        unsigned int bits = 0;
+       int ret;
 
-       /* FIXME: validate clock source */
        switch (counter_dev->variant) {
        case ni_gpct_variant_660x:
-               bits |= ni_660x_clk_src(clock_source);
+               ret = ni_660x_clk_src(clock_source, &bits);
                break;
        case ni_gpct_variant_e_series:
        case ni_gpct_variant_m_series:
        default:
-               bits |= ni_m_clk_src(clock_source);
+               ret = ni_m_clk_src(clock_source, &bits);
                break;
        }
+       if (ret) {
+               struct comedi_device *dev = counter_dev->dev;
+
+               dev_err(dev->class_dev, "invalid clock source 0x%x\n",
+                       clock_source);
+               return ret;
+       }
+
        if (clock_source & NI_GPCT_INVERT_CLOCK_SRC_BIT)
                bits |= GI_SRC_POL_INVERT;
        ni_tio_set_bits(counter, NITIO_INPUT_SEL_REG(cidx),