+ /* timeout in us */
+ target_timeout = data->timeout_ns / 1000 +
+ data->timeout_clks / host->clock;
+
+ /*
+ * Figure out needed cycles.
+ * We do this in steps in order to fit inside a 32 bit int.
+ * The first step is the minimum timeout, which will have a
+ * minimum resolution of 6 bits:
+ * (1) 2^13*1000 > 2^22,
+ * (2) host->timeout_clk < 2^16
+ * =>
+ * (1) / (2) > 2^6
+ */
+ count = 0;
+ current_timeout = (1 << 13) * 1000 / host->timeout_clk;
+ while (current_timeout < target_timeout) {
+ count++;
+ current_timeout <<= 1;
+ if (count >= 0xF)
+ break;
+ }
+
+ if (count >= 0xF) {
+ printk(KERN_WARNING "%s: Too large timeout requested!\n",
+ mmc_hostname(host->mmc));
+ count = 0xE;
+ }
+
+ writeb(count, host->ioaddr + SDHCI_TIMEOUT_CONTROL);
+