static int freq_to_dsconfig(struct iw_freq *freq, unsigned int *dsconfig)
 {
        if (freq->m < 1000 && freq->e == 0) {
-               if (freq->m >= 1 &&
-                       freq->m <= (sizeof(freq_chan) / sizeof(freq_chan[0])))
+               if (freq->m >= 1 && freq->m <= ARRAY_SIZE(freq_chan))
                        *dsconfig = freq_chan[freq->m - 1] * 1000;
                else
                        return -1;
                range->throughput = 11 * 1000 * 1000 / 2;
        }
 
-       range->num_channels = (sizeof(freq_chan)/sizeof(freq_chan[0]));
+       range->num_channels = ARRAY_SIZE(freq_chan);
 
-       for (i = 0; i < (sizeof(freq_chan)/sizeof(freq_chan[0])) &&
-                       i < IW_MAX_FREQUENCIES; i++) {
+       for (i = 0; i < ARRAY_SIZE(freq_chan) && i < IW_MAX_FREQUENCIES; i++) {
                range->freq[i].i = i + 1;
                range->freq[i].m = freq_chan[i] * 100000;
                range->freq[i].e = 1;