cfa10036: Retrieve the RAM size at runtime

The cfa-10036 comes in two flavours, with either 128MB or 256MB of RAM
on it.

Since it's not stored anywhere, we need to runtime detect it by
introducing the cfa10036_get_ram_size function.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 17 insertions, 1 deletions

diff --git a/arch/arm/boards/crystalfontz-cfa10036/cfa10036.c b/arch/arm/boards/crystalfontz-cfa10036/cfa10036.c
index 1bc20cf21c..a37b0898eb 100644
--- a/arch/arm/boards/crystalfontz-cfa10036/cfa10036.c
+++ b/arch/arm/boards/crystalfontz-cfa10036/cfa10036.c
@@ -90,9 +90,25 @@ static struct i2c_gpio_platform_data i2c_gpio_pdata = {
 	.udelay			= 5,		/* ~100 kHz */
 };
 
+void v5_mmu_cache_flush(void);
+long cfa10036_get_ram_size(void)
+{
+	volatile u32 *base = (void *)IMX_MEMORY_BASE;
+	volatile u32 *ofs = base + SZ_128M / sizeof(u32);
+
+	*base = *ofs = 0xdeadbeef;
+	*ofs = 0xbaadcafe;
+
+	v5_mmu_cache_flush();
+	if (*base == 0xbaadcafe)
+		return SZ_128M;
+	else
+		return SZ_256M;
+}
+
 static int cfa10036_mem_init(void)
 {
-	arm_add_mem_device("ram0", IMX_MEMORY_BASE, 128 * 1024 * 1024);
+	arm_add_mem_device("ram0", IMX_MEMORY_BASE, cfa10036_get_ram_size());
 
 	return 0;
 }