ARM: shmobile: r8a7740: add MERAM work-around

r8a7740 chip has lasting errata on MERAM buffer, and this patch adds
its work-around on setup-r8a7740.c
It solved CEU/VIO6C/2D-DMAC/VCP1/VPU5F/JPU/DISP memroy access error.

But MERAM driver can't control this issue,
since this work-around requires access to non-MERAM register address.
So, This it will be called as board specific code at this point.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tested-by: Simon Horman <horms@verge.net.au>
Acked-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

3 files changed, 20 insertions, 0 deletions

diff --git a/arch/arm/mach-shmobile/board-armadillo800eva.c b/arch/arm/mach-shmobile/board-armadillo800eva.c
index 9e37026ef9dd..6e6839d0a2dc 100644
--- a/arch/arm/mach-shmobile/board-armadillo800eva.c
+++ b/arch/arm/mach-shmobile/board-armadillo800eva.c
@@ -587,6 +587,7 @@ static void __init eva_init(void)
         eva_clock_init();
 
         r8a7740_pinmux_init();
+        r8a7740_meram_workaround();
 
         /* SCIFA1 */
         gpio_request(GPIO_FN_SCIFA1_RXD, NULL);
diff --git a/arch/arm/mach-shmobile/include/mach/common.h b/arch/arm/mach-shmobile/include/mach/common.h
index 01e2bc014f15..45e61dada030 100644
--- a/arch/arm/mach-shmobile/include/mach/common.h
+++ b/arch/arm/mach-shmobile/include/mach/common.h
@@ -77,6 +77,7 @@ extern void r8a7779_add_standard_devices(void);
 extern void r8a7779_clock_init(void);
 extern void r8a7779_pinmux_init(void);
 extern void r8a7779_pm_init(void);
+extern void r8a7740_meram_workaround(void);
 
 extern unsigned int r8a7779_get_core_count(void);
 extern int r8a7779_platform_cpu_kill(unsigned int cpu);
diff --git a/arch/arm/mach-shmobile/setup-r8a7740.c b/arch/arm/mach-shmobile/setup-r8a7740.c
index ec4eb49c1693..366311b3dc73 100644
--- a/arch/arm/mach-shmobile/setup-r8a7740.c
+++ b/arch/arm/mach-shmobile/setup-r8a7740.c
@@ -324,6 +324,24 @@ static struct platform_device *r8a7740_late_devices[] __initdata = {
         &i2c1_device,
 };
 
+/*
+ * r8a7740 chip has lasting errata on MERAM buffer.
+ * this is work-around for it.
+ * see
+ *      "Media RAM (MERAM)" on r8a7740 documentation
+ */
+#define MEBUFCNTR       0xFE950098
+void r8a7740_meram_workaround(void)
+{
+        void __iomem *reg;
+
+        reg = ioremap_nocache(MEBUFCNTR, 4);
+        if (reg) {
+                iowrite32(0x01600164, reg);
+                iounmap(reg);
+        }
+}
+
 #define ICCR    0x0004
 #define ICSTART 0x0070