* wakeup is anyhow controlled by the RIMSC and FIMSC registers.
*/
if (nmk_chip->sleepmode && on) {
- __nmk_gpio_set_slpm(nmk_chip, gpio % nmk_chip->chip.base,
+ __nmk_gpio_set_slpm(nmk_chip, gpio % NMK_GPIO_PER_CHIP,
NMK_GPIO_SLPM_WAKEUP_ENABLE);
}
ret = PTR_ERR(clk);
goto out_unmap;
}
+ clk_prepare(clk);
nmk_chip = kzalloc(sizeof(*nmk_chip), GFP_KERNEL);
if (!nmk_chip) {
dev_dbg(npct->dev, "enable group %s, %u pins\n", g->name, g->npins);
- /* Handle this special glitch on altfunction C */
+ /*
+ * If we're setting altfunc C by setting both AFSLA and AFSLB to 1,
+ * we may pass through an undesired state. In this case we take
+ * some extra care.
+ *
+ * Safe sequence used to switch IOs between GPIO and Alternate-C mode:
+ * - Save SLPM registers (since we have a shadow register in the
+ * nmk_chip we're using that as backup)
+ * - Set SLPM=0 for the IOs you want to switch and others to 1
+ * - Configure the GPIO registers for the IOs that are being switched
+ * - Set IOFORCE=1
+ * - Modify the AFLSA/B registers for the IOs that are being switched
+ * - Set IOFORCE=0
+ * - Restore SLPM registers
+ * - Any spurious wake up event during switch sequence to be ignored
+ * and cleared
+ *
+ * We REALLY need to save ALL slpm registers, because the external
+ * IOFORCE will switch *all* ports to their sleepmode setting to as
+ * to avoid glitches. (Not just one port!)
+ */
glitch = (g->altsetting == NMK_GPIO_ALT_C);
if (glitch) {