[U-Boot] [PATCH 6/7] ARM: at91: mpddrc: add lpddr2 initialization procedure

Eugen.Hristev at microchip.com
2019-08-08T07:48:34Z

Implement the lpddr2 initialization procedure for at91 mpddrc multi-port
ddram controller.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
---
arch/arm/mach-at91/include/mach/atmel_mpddrc.h | 23 ++++
arch/arm/mach-at91/mpddrc.c | 162 +++++++++++++++++++++++++
2 files changed, 185 insertions(+)

diff --git a/arch/arm/mach-at91/include/mach/atmel_mpddrc.h b/arch/arm/mach-at91/include/mach/atmel_mpddrc.h
index 45a76a6..40ec87e 100644
--- a/arch/arm/mach-at91/include/mach/atmel_mpddrc.h
+++ b/arch/arm/mach-at91/include/mach/atmel_mpddrc.h
@@ -18,6 +18,9 @@ struct atmel_mpddrc_config {
u32 tpr1;
u32 tpr2;
u32 md;
+ u32 lpddr23_lpr;
+ u32 cal_mr4;
+ u32 tim_cal;
};

/*
@@ -61,6 +64,10 @@ int ddr2_init(const unsigned int base,
const unsigned int ram_address,
const struct atmel_mpddrc_config *mpddr_value);

+int lpddr2_init(const unsigned int base,
+ const unsigned int ram_address,
+ const struct atmel_mpddrc_config *mpddr_value);
+
int ddr3_init(const unsigned int base,
const unsigned int ram_address,
const struct atmel_mpddrc_config *mpddr_value);
@@ -74,6 +81,11 @@ int ddr3_init(const unsigned int base,
#define ATMEL_MPDDRC_MR_MODE_EXT_LMR_CMD 0x5
#define ATMEL_MPDDRC_MR_MODE_DEEP_CMD 0x6
#define ATMEL_MPDDRC_MR_MODE_LPDDR2_CMD 0x7
+#define ATMEL_MPDDRC_MR_MRS(v) (((v) & 0xFF) << 0x8)
+
+/* Bit field in refresh timer register */
+#define ATMEL_MPDDRC_RTR_ADJ_REF (0x1 << 16)
+#define ATMEL_MPDDRC_RTR_MR4VALUE(v) (((v) & 0x7) << 20)

/* Bit field in configuration register */
#define ATMEL_MPDDRC_CR_NC_MASK 0x3
@@ -157,6 +169,7 @@ int ddr3_init(const unsigned int base,
#define ATMEL_MPDDRC_MD_DDR3_SDRAM 0x4
#define ATMEL_MPDDRC_MD_LPDDR3_SDRAM 0x5
#define ATMEL_MPDDRC_MD_DDR2_SDRAM 0x6
+#define ATMEL_MPDDRC_MD_LPDDR2_SDRAM 0x7
#define ATMEL_MPDDRC_MD_DBW_MASK (0x1 << 4)
#define ATMEL_MPDDRC_MD_DBW_32_BITS (0x0 << 4)
#define ATMEL_MPDDRC_MD_DBW_16_BITS (0x1 << 4)
@@ -206,4 +219,14 @@ int ddr3_init(const unsigned int base,
#define ATMEL_MPDDRC_RD_DATA_PATH_SHIFT_TWO_CYCLE 0x2
#define ATMEL_MPDDRC_RD_DATA_PATH_SHIFT_THREE_CYCLE 0x3

+/* Bit field in LPDDR2 - LPDDR3 Low Power Register */
+#define ATMEL_MPDDRC_LPDDR23_LPR_DS(x) (((x) & 0xf) << 24)
+
+/* Bit field in CAL_MR4 Calibration and MR4 Register */
+#define ATMEL_MPDDRC_CAL_MR4_COUNT_CAL(x) (((x) & 0xffff) << 0)
+#define ATMEL_MPDDRC_CAL_MR4_MR4R(x) (((x) & 0xffff) << 16)
+
+/* Bit field in TIM_CAL Timing Calibration Register */
+#define ATMEL_MPDDRC_CALR_ZQCS(x) (((x) & 0xff) << 0)
+
#endif
diff --git a/arch/arm/mach-at91/mpddrc.c b/arch/arm/mach-at91/mpddrc.c
index 81ccd6a..3df0ea7 100644
--- a/arch/arm/mach-at91/mpddrc.c
+++ b/arch/arm/mach-at91/mpddrc.c
@@ -10,6 +10,7 @@
#include <common.h>
#include <asm/io.h>
#include <asm/arch/atmel_mpddrc.h>
+#include <asm/arch/at91_common.h>

#define SAMA5D3_MPDDRC_VERSION 0x140

@@ -18,6 +19,7 @@ static inline void atmel_mpddr_op(const struct atmel_mpddr *mpddr,
u32 ram_address)
{
writel(mode, &mpddr->mr);
+ dmb();
writel(0, ram_address);
}

@@ -227,3 +229,163 @@ int ddr3_init(const unsigned int base,

return 0;
}
+
+int lpddr2_init(const unsigned int base,
+ const unsigned int ram_address,
+ const struct atmel_mpddrc_config *mpddr_value)
+{
+ struct atmel_mpddr *mpddr = (struct atmel_mpddr *)base;
+ u32 reg;
+
+ writel(mpddr_value->lpddr23_lpr, &mpddr->lpddr23_lpr);
+
+ writel(mpddr_value->tim_cal, &mpddr->tim_cal);
+
+ /* 1. Program the memory device type */
+ writel(mpddr_value->md, &mpddr->md);
+
+ /*
+ * 2. Program features of the LPDDR2-SDRAM device and timing parameters
+ */
+ writel(mpddr_value->cr, &mpddr->cr);
+
+ writel(mpddr_value->tpr0, &mpddr->tpr0);
+ writel(mpddr_value->tpr1, &mpddr->tpr1);
+ writel(mpddr_value->tpr2, &mpddr->tpr2);
+
+ /* 3. A NOP command is issued to the LPDDR2-SDRAM */
+ atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_NOP_CMD, ram_address);
+
+ /*
+ * 3bis. Add memory barrier then Perform a write access to
+ * any low-power DDR2-SDRAM address to acknowledge the command.
+ */
+
+ dmb();
+ writel(0, ram_address);
+
+ /* 4. A pause of at least 100 ns must be observed before a single toggle */
+ udelay(1);
+
+ /* 5. A NOP command is issued to the LPDDR2-SDRAM */
+ atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_NOP_CMD, ram_address);
+
+ /* 6. A pause of at least 200 us must be observed before a Reset Command */
+ udelay(200);
+
+ /* 7. A Reset command is issued to the low-power DDR2-SDRAM. */
+ atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_LPDDR2_CMD |
+ ATMEL_MPDDRC_MR_MRS(63), ram_address);
+
+ /*
+ * 8. A pause of at least tINIT5 must be observed before issuing
+ * any commands
+ */
+ udelay(1);
+
+ /* 9. A Calibration command is issued to the low-power DDR2-SDRAM. */
+ reg = readl(&mpddr->cr);
+ reg &= ~ATMEL_MPDDRC_CR_ZQ_RESET;
+ reg |= ATMEL_MPDDRC_CR_ZQ_RESET;
+ writel(reg, &mpddr->cr);
+
+ atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_LPDDR2_CMD |
+ ATMEL_MPDDRC_MR_MRS(10), ram_address);
+
+ /*
+ * 9bis: The ZQ Calibration command is now issued.
+ * Program the type of calibration in the MPDDRC_CR: set the
+ * ZQ field to the SHORT value.
+ */
+ reg = readl(&mpddr->cr);
+ reg &= ~ATMEL_MPDDRC_CR_ZQ_RESET;
+ reg |= ATMEL_MPDDRC_CR_ZQ_SHORT;
+ writel(reg, &mpddr->cr);
+
+ /*
+ * 10: A Mode Register Write command with 1 to the MRS field
+ * is issued to the low-power DDR2-SDRAM.
+ */
+ atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_LPDDR2_CMD |
+ ATMEL_MPDDRC_MR_MRS(1), ram_address);
+
+ /*
+ * 11: A Mode Register Write command with 2 to the MRS field
+ * is issued to the low-power DDR2-SDRAM.
+ */
+ atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_LPDDR2_CMD |
+ ATMEL_MPDDRC_MR_MRS(2), ram_address);
+
+ /*
+ * 12: A Mode Register Write command with 3 to the MRS field
+ * is issued to the low-power DDR2-SDRAM.
+ */
+ atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_LPDDR2_CMD |
+ ATMEL_MPDDRC_MR_MRS(3), ram_address);
+
+ /*
+ * 13: A Mode Register Write command with 16 to the MRS field
+ * is issued to the low-power DDR2-SDRAM.
+ */
+ atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_LPDDR2_CMD |
+ ATMEL_MPDDRC_MR_MRS(16), ram_address);
+
+ /*
+ * 14: In the DDR Configuration Register, open the input buffers.
+ */
+#ifdef CONFIG_ATMEL_SFR
+ configure_ddrcfg_input_buffers(true);
+#endif
+
+ /* 15. A NOP command is issued to the LPDDR2-SDRAM */
+ atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_NOP_CMD, ram_address);
+
+ /*
+ * 16: A Mode Register Write command with 5 to the MRS field
+ * is issued to the low-power DDR2-SDRAM.
+ */
+ atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_LPDDR2_CMD |
+ ATMEL_MPDDRC_MR_MRS(5), ram_address);
+
+ /*
+ * 17: A Mode Register Write command with 6 to the MRS field
+ * is issued to the low-power DDR2-SDRAM.
+ */
+ atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_LPDDR2_CMD |
+ ATMEL_MPDDRC_MR_MRS(6), ram_address);
+
+ /*
+ * 18: A Mode Register Write command with 8 to the MRS field
+ * is issued to the low-power DDR2-SDRAM.
+ */
+ atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_LPDDR2_CMD |
+ ATMEL_MPDDRC_MR_MRS(8), ram_address);
+
+ /*
+ * 19: A Mode Register Write command with 0 to the MRS field
+ * is issued to the low-power DDR2-SDRAM.
+ */
+ atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_LPDDR2_CMD |
+ ATMEL_MPDDRC_MR_MRS(0), ram_address);
+
+ /*
+ * 20: A Normal Mode command is provided.
+ */
+ atmel_mpddr_op(mpddr, ATMEL_MPDDRC_MR_MODE_NORMAL_CMD, ram_address);
+
+ /* 21: In the DDR Configuration Register, close the input buffers. */
+#ifdef CONFIG_ATMEL_SFR
+ configure_ddrcfg_input_buffers(false);
+#endif
+
+ /*
+ * 22: Write the refresh rate into the COUNT field in the MPDDRC
+ * Refresh Timer Register.
+ */
+ writel(mpddr_value->rtr, &mpddr->rtr);
+
+ /* 23. Configre CAL MR4 register */
+ writel(mpddr_value->cal_mr4, &mpddr->cal_mr4);
+
+ return 0;
+}
--
2.7.4