mfd: db8500-prcmu reset code retrieval

This implements the reset code retrieval function so we can
ipso facto get to know how the system was reset.

Signed-off-by: Sebastian Rasmussen <sebastian.rasmussen@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/db8500-prcmu.c

@@ -1835,6 +1835,17 @@ void db8500_prcmu_system_reset(u16 reset_code)
 	writel(1, PRCM_APE_SOFTRST);
 }
 
+/**
+ * db8500_prcmu_get_reset_code - Retrieve SW reset reason code
+ *
+ * Retrieves the reset reason code stored by prcmu_system_reset() before
+ * last restart.
+ */
+u16 db8500_prcmu_get_reset_code(void)
+{
+	return readw(tcdm_base + PRCM_SW_RST_REASON);
+}
+
 /**
  * prcmu_reset_modem - ask the PRCMU to reset modem
  */