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-rw-r--r--arch/arm/mach-sunxi/dram_sun50i_h6.c100
1 files changed, 56 insertions, 44 deletions
diff --git a/arch/arm/mach-sunxi/dram_sun50i_h6.c b/arch/arm/mach-sunxi/dram_sun50i_h6.c
index 9e34da47479..32ec0bc4cd4 100644
--- a/arch/arm/mach-sunxi/dram_sun50i_h6.c
+++ b/arch/arm/mach-sunxi/dram_sun50i_h6.c
@@ -37,9 +37,9 @@
static void mctl_sys_init(struct dram_para *para);
static void mctl_com_init(struct dram_para *para);
-static void mctl_channel_init(struct dram_para *para);
+static bool mctl_channel_init(struct dram_para *para);
-static void mctl_core_init(struct dram_para *para)
+static bool mctl_core_init(struct dram_para *para)
{
mctl_sys_init(para);
mctl_com_init(para);
@@ -51,7 +51,7 @@ static void mctl_core_init(struct dram_para *para)
default:
panic("Unsupported DRAM type!");
};
- mctl_channel_init(para);
+ return mctl_channel_init(para);
}
/* PHY initialisation */
@@ -411,7 +411,7 @@ static void mctl_bit_delay_set(struct dram_para *para)
}
}
-static void mctl_channel_init(struct dram_para *para)
+static bool mctl_channel_init(struct dram_para *para)
{
struct sunxi_mctl_com_reg * const mctl_com =
(struct sunxi_mctl_com_reg *)SUNXI_DRAM_COM_BASE;
@@ -528,46 +528,15 @@ static void mctl_channel_init(struct dram_para *para)
clrbits_le32(&mctl_phy->dx[i].gcr[3], ~0x3ffff);
udelay(10);
- if (readl(&mctl_phy->pgsr[0]) & 0x400000)
- {
- /* Check for single rank and optionally half DQ. */
- if ((readl(&mctl_phy->dx[0].rsr[0]) & 0x3) == 2 &&
- (readl(&mctl_phy->dx[1].rsr[0]) & 0x3) == 2) {
- para->ranks = 1;
-
- if ((readl(&mctl_phy->dx[2].rsr[0]) & 0x3) != 2 ||
- (readl(&mctl_phy->dx[3].rsr[0]) & 0x3) != 2)
- para->bus_full_width = 0;
-
- /* Restart DRAM initialization from scratch. */
- mctl_core_init(para);
- return;
- }
-
- /*
- * Check for dual rank and half DQ. NOTE: This combination
- * is highly unlikely and was not tested. Condition is the
- * same as in libdram, though.
- */
- if ((readl(&mctl_phy->dx[0].rsr[0]) & 0x3) == 0 &&
- (readl(&mctl_phy->dx[1].rsr[0]) & 0x3) == 0) {
- para->bus_full_width = 0;
-
- /* Restart DRAM initialization from scratch. */
- mctl_core_init(para);
- return;
- }
-
- panic("This DRAM setup is currently not supported.\n");
- }
-
if (readl(&mctl_phy->pgsr[0]) & 0xff00000) {
/* Oops! There's something wrong! */
debug("PLL = %x\n", readl(0x3001010));
debug("DRAM PHY PGSR0 = %x\n", readl(&mctl_phy->pgsr[0]));
for (i = 0; i < 4; i++)
debug("DRAM PHY DX%dRSR0 = %x\n", i, readl(&mctl_phy->dx[i].rsr[0]));
- panic("Error while initializing DRAM PHY!\n");
+ debug("Error while initializing DRAM PHY!\n");
+
+ return false;
}
if (sunxi_dram_is_lpddr(para->type))
@@ -582,13 +551,59 @@ static void mctl_channel_init(struct dram_para *para)
writel(0xffffffff, &mctl_com->maer0);
writel(0x7ff, &mctl_com->maer1);
writel(0xffff, &mctl_com->maer2);
+
+ return true;
+}
+
+static void mctl_auto_detect_rank_width(struct dram_para *para)
+{
+ /* this is minimum size that it's supported */
+ para->cols = 8;
+ para->rows = 13;
+
+ /*
+ * Previous versions of this driver tried to auto detect the rank
+ * and width by looking at controller registers. However this proved
+ * to be not reliable, so this approach here is the more robust
+ * solution. Check the git history for details.
+ *
+ * Strategy here is to test most demanding combination first and least
+ * demanding last, otherwise HW might not be fully utilized. For
+ * example, half bus width and rank = 1 combination would also work
+ * on HW with full bus width and rank = 2, but only 1/4 RAM would be
+ * visible.
+ */
+
+ debug("testing 32-bit width, rank = 2\n");
+ para->bus_full_width = 1;
+ para->ranks = 2;
+ if (mctl_core_init(para))
+ return;
+
+ debug("testing 32-bit width, rank = 1\n");
+ para->bus_full_width = 1;
+ para->ranks = 1;
+ if (mctl_core_init(para))
+ return;
+
+ debug("testing 16-bit width, rank = 2\n");
+ para->bus_full_width = 0;
+ para->ranks = 2;
+ if (mctl_core_init(para))
+ return;
+
+ debug("testing 16-bit width, rank = 1\n");
+ para->bus_full_width = 0;
+ para->ranks = 1;
+ if (mctl_core_init(para))
+ return;
+
+ panic("This DRAM setup is currently not supported.\n");
}
static void mctl_auto_detect_dram_size(struct dram_para *para)
{
/* TODO: non-(LP)DDR3 */
- /* Detect rank number and half DQ by the code in mctl_channel_init. */
- mctl_core_init(para);
/* detect row address bits */
para->cols = 8;
@@ -652,10 +667,6 @@ unsigned long sunxi_dram_init(void)
(struct sunxi_mctl_com_reg *)SUNXI_DRAM_COM_BASE;
struct dram_para para = {
.clk = CONFIG_DRAM_CLK,
- .ranks = 2,
- .cols = 11,
- .rows = 14,
- .bus_full_width = 1,
#ifdef CONFIG_SUNXI_DRAM_H6_LPDDR3
.type = SUNXI_DRAM_TYPE_LPDDR3,
.dx_read_delays = SUN50I_H6_LPDDR3_DX_READ_DELAYS,
@@ -673,6 +684,7 @@ unsigned long sunxi_dram_init(void)
setbits_le32(0x7010310, BIT(8));
clrbits_le32(0x7010318, 0x3f);
+ mctl_auto_detect_rank_width(&para);
mctl_auto_detect_dram_size(&para);
mctl_core_init(&para);