plugins: cn0540: allow up to 64 GPIOs (one-bit-adc-dac) instances

The plugin supports 8 GPIOs (as is the design of the CN0540 board). With some minor customizations, more GPIOs can be adapted (for some extra controls). When that happens, OSC will crash as 'gpio_ch[++idx].gpio = iio_device_find_channel()' will go beyond the size of the gpio_ch[] array. So, a quick fix is to just allow more GPIOs (64 should be enough for anyone). But mainly, it would be guard against going above the size of the gpio_ch[] array. Signed-off-by: Alexandru Ardelean <[email protected]>
analogdevicesinc · Oct 13, 2023 · 22bbffd · 22bbffd
1 parent 2b4e48b
commit 22bbffd
Showing 1 changed file with 9 additions and 4 deletions.
diff --git a/plugins/cn0540.c b/plugins/cn0540.c
@@ -36,7 +36,7 @@
 #define CALIB_MAX_ITER 20
 #define XADC_VREF 3.3
 #define XADC_RES 12
-#define NUM_GPIOS 8
+#define MAX_NUM_GPIOS 64
 #define NUM_ANALOG_PINS 6
 
 struct iio_gpio {
@@ -52,7 +52,7 @@ static struct iio_context *ctx;
 static struct iio_channel *adc_ch;
 static struct iio_channel *dac_ch;
 static struct iio_channel *analog_in[NUM_ANALOG_PINS];
-static struct iio_gpio gpio_ch[NUM_GPIOS];
+static struct iio_gpio gpio_ch[MAX_NUM_GPIOS];
 static struct iio_widget iio_widgets[25];
 static unsigned int num_widgets;
 
@@ -102,7 +102,7 @@ static gboolean cn0540_get_gpio_state(const char* gpio_name)
  long long readback = -1;
  int idx;
 
- for(idx = 0; idx < NUM_GPIOS; idx++) {
+ for(idx = 0; idx < MAX_NUM_GPIOS; idx++) {
  if(strstr(gpio_ch[idx].label, gpio_name)) {
  iio_channel_attr_read_longlong(gpio_ch[idx].gpio, "raw",
  &readback);
@@ -120,7 +120,7 @@ static void cn0540_set_gpio_state(const char* gpio_name, gboolean state)
 {
  int idx;
 
- for(idx = 0; idx < NUM_GPIOS; idx++) {
+ for(idx = 0; idx < MAX_NUM_GPIOS; idx++) {
  if (strstr(gpio_ch[idx].label, gpio_name)) {
  iio_channel_attr_write_longlong(gpio_ch[idx].gpio,
  "raw", (long long)state);
@@ -354,6 +354,11 @@ static void cn0540_get_channels()
  dac_ch = iio_device_find_channel(iio_dac, DAC_DEVICE_CH, TRUE);
 
  while(1) {
+ if (idx == MAX_NUM_GPIOS) {
+ fprintf(stderr, "CN0540 plugin supports 64 GPIOs max\n");
+ break;
+ }
+
  gpio_ch[++idx].gpio = iio_device_find_channel(iio_gpio, label,
  direction);
  if (gpio_ch[idx].gpio != NULL){