[ARM] S3C: Add debug to UART save and a per-arch callback pre-restore

Add a simple debug message on saving the UART state and add a per-arch
pre-restore function to be used by the s3c64xx restore code to ensure
the UARTs control registers do not go through any illegal state changes.
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

arch/arm/plat-s3c/pm.c

@@ -83,6 +83,9 @@ static void s3c_pm_save_uart(unsigned int uart, struct pm_uart_save *save)
 	save->ufcon = __raw_readl(regs + S3C2410_UFCON);
 	save->umcon = __raw_readl(regs + S3C2410_UMCON);
 	save->ubrdiv = __raw_readl(regs + S3C2410_UBRDIV);
+
+	S3C_PMDBG("UART[%d]: ULCON=%04x, UCON=%04x, UFCON=%04x, UBRDIV=%04x\n",
+		  uart, save->ulcon, save->ucon, save->ufcon, save->ubrdiv);
 }
 
 static void s3c_pm_save_uarts(void)
@@ -98,6 +101,8 @@ static void s3c_pm_restore_uart(unsigned int uart, struct pm_uart_save *save)
 {
 	void __iomem *regs = S3C_VA_UARTx(uart);
 
+	s3c_pm_arch_update_uart(regs, save);
+
 	__raw_writel(save->ulcon, regs + S3C2410_ULCON);
 	__raw_writel(save->ucon,  regs + S3C2410_UCON);
 	__raw_writel(save->ufcon, regs + S3C2410_UFCON);

arch/arm/plat-s3c24xx/include/plat/pm-core.h

@@ -57,3 +57,8 @@ static inline void s3c_pm_arch_show_resume_irqs(void)
 	s3c_pm_show_resume_irqs(IRQ_EINT4-4, __raw_readl(S3C2410_EINTPEND),
 				s3c_irqwake_eintmask);
 }
+
+static inline void s3c_pm_arch_update_uart(void __iomem *regs,
+					   struct pm_uart_save *save)
+{
+}