[U-Boot] [PATCH v3 5/6] arm: atmel: add ddr2 initialization function

Andreas Bießmann
2013-11-13T13:03:09Z

Hi Bo,

On 11/06/2013 06:29 AM, Bo Shen wrote:
> The MPDDRC supports different type of SDRAM
> This patch add ddr2 initialization function
>
> Signed-off-by: Bo Shen <voice.shen@atmel.com>
>
> ---
> Changes in v3:
> - Move to at91 common folder
>
> Changes in v2:
> - None
>
> arch/arm/cpu/at91-common/Makefile | 32 +++++++
> arch/arm/cpu/at91-common/mpddrc.c | 123 +++++++++++++++++++++++++
> arch/arm/include/asm/arch-at91/atmel_mpddrc.h | 111 ++++++++++++++++++++++
> spl/Makefile | 4 +
> 4 files changed, 270 insertions(+)
> create mode 100644 arch/arm/cpu/at91-common/Makefile
> create mode 100644 arch/arm/cpu/at91-common/mpddrc.c
> create mode 100644 arch/arm/include/asm/arch-at91/atmel_mpddrc.h
>
> diff --git a/arch/arm/cpu/at91-common/Makefile b/arch/arm/cpu/at91-common/Makefile
> new file mode 100644
> index 0000000..6f1a9e6
> --- /dev/null
> +++ b/arch/arm/cpu/at91-common/Makefile
> @@ -0,0 +1,32 @@
> +#
> +# (C) Copyright 2000-2008
> +# Wolfgang Denk, DENX Software Engineering, wd at denx.de.
> +#
> +# (C) Copyright 2013 Atmel Corporation
> +# Bo Shen <voice.shen@atmel.com>
> +#
> +# SPDX-License-Identifier: GPL-2.0+
> +#
> +
> +include $(TOPDIR)/config.mk
> +
> +LIB = $(obj)libat91-common.o
> +
> +COBJS-$(CONFIG_SPL_BUILD) += mpddrc.o
> +
> +SRCS := $(SOBJS-y:.o=.S) $(COBJS-y:.o=.c)
> +OBJS := $(addprefix $(obj),$(SOBJS-y) $(COBJS-y))
> +
> +all: $(obj).depend $(LIB)
> +
> +$(LIB): $(OBJS)
> + $(call cmd_link_o_target, $(OBJS))
> +
> +#########################################################################
> +
> +# defines $(obj).depend target
> +include $(SRCTREE)/rules.mk
> +
> +sinclude $(obj).depend
> +
> +#########################################################################

please rewrite in KBuild style.

> diff --git a/arch/arm/cpu/at91-common/mpddrc.c b/arch/arm/cpu/at91-common/mpddrc.c
> new file mode 100644
> index 0000000..1abde1e
> --- /dev/null
> +++ b/arch/arm/cpu/at91-common/mpddrc.c
> @@ -0,0 +1,123 @@
> +/*
> + * Copyright (C) 2013 Atmel Corporation
> + * Bo Shen <voice.shen@atmel.com>
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <asm/io.h>
> +#include <asm/arch/atmel_mpddrc.h>
> +
> +static void atmel_mpddr_op(int mode, u32 ram_address)

static inline, could give the compiler a hint to optimize here.

> +{
> + struct atmel_mpddr *mpddr = (struct atmel_mpddr *)ATMEL_BASE_MPDDRC;
> +
> + writel(mode, &mpddr->mr);
> + writel(0, ram_address);
> +}
> +
> +int ddr2_init(u32 ram_address, struct atmel_mpddr *mpddr_value)

could you please constify mpddr_value for the very same reason?

> +{
> + struct atmel_mpddr *mpddr = (struct atmel_mpddr *)ATMEL_BASE_MPDDRC;
> + u32 ba_off, cr;
> +
> + /* Compute bank offset according to NC in configuration register */
> + ba_off = (mpddr_value->cr & ATMEL_MPDDRC_CR_NC_MASK) + 9;
> + if (!(mpddr_value->cr & ATMEL_MPDDRC_CR_DECOD_INTERLEAVED))
> + ba_off += ((mpddr->cr & ATMEL_MPDDRC_CR_NR_MASK) >> 2) + 11;
> +
> + ba_off += (mpddr_value->mdr & ATMEL_MPDDRC_MDR_DBW_MASK) ? 1 : 2;
> +
> + /* Program the memory device type into the memory device register */
> + writel(mpddr_value->mdr, &mpddr->mdr);
> +
> + /* Program the configuration register */
> + writel(mpddr_value->cr, &mpddr->cr);
> +
> + /* Program the timing register */
> + writel(mpddr_value->tp0r, &mpddr->tp0r);
> + writel(mpddr_value->tp1r, &mpddr->tp1r);
> + writel(mpddr_value->tp2r, &mpddr->tp2r);
> +
> + /* Issue a NOP command */
> + atmel_mpddr_op(ATMEL_MPDDRC_MR_NOP_CMD, ram_address);
> +
> + /* A 200 us is provided to precede any signal toggle */
> + udelay(200);
> +
> + /* Issue a NOP command */
> + atmel_mpddr_op(ATMEL_MPDDRC_MR_NOP_CMD, ram_address);
> +
> + /* Issue an all banks precharge command */
> + atmel_mpddr_op(ATMEL_MPDDRC_MR_PRCGALL_CMD, ram_address);
> +
> + /* Issue an extended mode register set(EMRS2) to choose operation */
> + atmel_mpddr_op(ATMEL_MPDDRC_MR_EXT_LMR_CMD,
> + ram_address + (0x2 << ba_off));
> +
> + /* Issue an extended mode register set(EMRS3) to set EMSR to 0 */
> + atmel_mpddr_op(ATMEL_MPDDRC_MR_EXT_LMR_CMD,
> + ram_address + (0x3 << ba_off));
> +
> + /*
> + * Issue an extended mode register set(EMRS1) to enable DLL and
> + * program D.I.C (output driver impedance control)
> + */
> + atmel_mpddr_op(ATMEL_MPDDRC_MR_EXT_LMR_CMD,
> + ram_address + (0x1 << ba_off));
> +
> + /* Enable DLL reset */
> + cr = readl(&mpddr->cr);
> + writel(cr | ATMEL_MPDDRC_CR_EN_RESET_DLL, &mpddr->cr);
> +
> + /* A mode register set(MRS) cycle is issued to reset DLL */
> + atmel_mpddr_op(ATMEL_MPDDRC_MR_LMR_CMD, ram_address);
> +
> + /* Issue an all banks precharge command */
> + atmel_mpddr_op(ATMEL_MPDDRC_MR_PRCGALL_CMD, ram_address);
> +
> + /* Two auto-refresh (CBR) cycles are provided */
> + atmel_mpddr_op(ATMEL_MPDDRC_MR_RFSH_CMD, ram_address);
> + atmel_mpddr_op(ATMEL_MPDDRC_MR_RFSH_CMD, ram_address);
> +
> + /* Disable DLL reset */
> + cr = readl(&mpddr->cr);
> + writel(cr & (~ATMEL_MPDDRC_CR_EN_RESET_DLL), &mpddr->cr);
> +
> + /* A mode register set (MRS) cycle is issued to disable DLL reset */
> + atmel_mpddr_op(ATMEL_MPDDRC_MR_LMR_CMD, ram_address);
> +
> + /* Set OCD calibration in defautl state */

typo default

> + cr = readl(&mpddr->cr);
> + writel(cr | ATMEL_MPDDRC_CR_OCD_DEFAULT, &mpddr->cr);
> +
> + /*
> + * An extended mode register set (EMRS1) cycle is issued
> + * to OCD default value
> + */
> + atmel_mpddr_op(ATMEL_MPDDRC_MR_EXT_LMR_CMD,
> + ram_address + (0x1 << ba_off));
> +
> + /* OCD calibration mode exit */
> + cr = readl(&mpddr->cr);
> + writel(cr & (~ATMEL_MPDDRC_CR_OCD_DEFAULT), &mpddr->cr);
> +
> + /*
> + * An extended mode register set (EMRS1) cycle is issued
> + * to enable OCD exit
> + */
> + atmel_mpddr_op(ATMEL_MPDDRC_MR_EXT_LMR_CMD,
> + ram_address + (0x1 << ba_off));
> +
> + /* A nornal mode command is provided */
> + atmel_mpddr_op(ATMEL_MPDDRC_MR_NORMAL_CMD, ram_address);
> +
> + /* Perform a write access to any DDR2-SDRAM address */
> + writel(0, ram_address);
> +
> + /* Write the refresh rate */
> + writel(mpddr_value->rtr, &mpddr->rtr);
> +

I haven't checked that sequence deeply, I trust in you that it is correct ;)

> + return 0;
> +}
> diff --git a/arch/arm/include/asm/arch-at91/atmel_mpddrc.h b/arch/arm/include/asm/arch-at91/atmel_mpddrc.h
> new file mode 100644
> index 0000000..abd8b68
> --- /dev/null
> +++ b/arch/arm/include/asm/arch-at91/atmel_mpddrc.h
> @@ -0,0 +1,111 @@
> +/*
> + * Copyright (C) 2013 Atmel Corporation
> + * Bo Shen <voice.shen@atmel.com>
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +
> +#ifndef __ATMEL_MPDDRC_H__
> +#define __ATMEL_MPDDRC_H__
> +
> +struct atmel_mpddr {
> + u32 mr;
> + u32 rtr;
> + u32 cr;
> + u32 tp0r;

Datasheet names them tprX

> + u32 tp1r;
> + u32 tp2r;
> + u32 reserved[2];
> + u32 mdr;

Datasheet names it just md.

I think it would be good to also add the other register positions or at
least mention that these the only one needed currently (in a comment
right here in the struct).

> +};
> +
> +int ddr2_init(unsigned int ram_address,
> + struct atmel_mpddr *mpddr);
> +
> +/* bit field in mode register */
> +#define ATMEL_MPDDRC_MR_NORMAL_CMD 0x0
> +#define ATMEL_MPDDRC_MR_NOP_CMD 0x1
> +#define ATMEL_MPDDRC_MR_PRCGALL_CMD 0x2
> +#define ATMEL_MPDDRC_MR_LMR_CMD 0x3
> +#define ATMEL_MPDDRC_MR_RFSH_CMD 0x4
> +#define ATMEL_MPDDRC_MR_EXT_LMR_CMD 0x5
> +#define ATMEL_MPDDRC_MR_DEEP_CMD 0x6
> +#define ATMEL_MPDDRC_MR_LPDDR2_CMD 0x7

Could you please drop the tabs between 'define' and the definition.

> +
> +/* bit field in configuration register */
> +#define ATMEL_MPDDRC_CR_NC_MASK 0x3
> +#define ATMEL_MPDDRC_CR_NC_COL_9 0x0
> +#define ATMEL_MPDDRC_CR_NC_COL_10 0x1
> +#define ATMEL_MPDDRC_CR_NC_COL_11 0x2
> +#define ATMEL_MPDDRC_CR_NC_COL_12 0x3
> +#define ATMEL_MPDDRC_CR_NR_MASK (0x3 << 2)
> +#define ATMEL_MPDDRC_CR_NR_ROW_11 (0x0 << 2)
> +#define ATMEL_MPDDRC_CR_NR_ROW_12 (0x1 << 2)
> +#define ATMEL_MPDDRC_CR_NR_ROW_13 (0x2 << 2)
> +#define ATMEL_MPDDRC_CR_NR_ROW_14 (0x3 << 2)
> +#define ATMEL_MPDDRC_CR_CAS (0x7 << 4)
> +#define ATMEL_MPDDRC_CR_CAS_2 (0x2 << 4)
> +#define ATMEL_MPDDRC_CR_CAS_3 (0x3 << 4)
> +#define ATMEL_MPDDRC_CR_CAS_4 (0x4 << 4)
> +#define ATMEL_MPDDRC_CR_CAS_5 (0x5 << 4)
> +#define ATMEL_MPDDRC_CR_CAS_6 (0x6 << 4)
> +#define ATMEL_MPDDRC_CR_EN_RESET_DLL (0x1 << 7)
> +#define ATMEL_MPDDRC_CR_DIC_DS (0x1 << 8)
> +#define ATMEL_MPDDRC_CR_DIS_DLL (0x1 << 9)
> +#define ATMEL_MPDDRC_CR_OCD_DEFAULT (0x7 << 12)
> +#define ATMEL_MPDDRC_CR_EN_ENRDM (0x1 << 17)
> +#define ATMEL_MPDDRC_CR_NB_8BANKS (0x1 << 20)
> +#define ATMEL_MPDDRC_CR_DIS_NDQS (0x1 << 21)
> +#define ATMEL_MPDDRC_CR_DECOD_INTERLEAVED (0x1 << 22)
> +#define ATMEL_MPDDRC_CR_UNAL_SUPPORTED (0x1 << 23)

Some of the defines have the strict scheme <offset><register name><field
name> with <offset> being ATMEL_MPDDRC, <register name> CR here and the
respective field names from datasheet. Some however have some more
information like UNAL_SUPPORTED or DECOD_INTERLEAVED (those two are Ok I
think, but we could discuss if we like to have the strict scheme or
leave some space). But EN_ENRDM is definitely too much ;)
Has anyone a opinion about the strict scheme?

Regarding EN_ENRDM I think using ENRDM_ON would be better.

> +
> +/* bit field in timing parameter 0 register */
> +#define ATMEL_MPDDRC_TP0R_TRAS_OFFSET 0
> +#define ATMEL_MPDDRC_TP0R_TRAS_MASK 0xf
> +#define ATMEL_MPDDRC_TP0R_TRCD_OFFSET 4
> +#define ATMEL_MPDDRC_TP0R_TRCD_MASK 0xf
> +#define ATMEL_MPDDRC_TP0R_TWR_OFFSET 8
> +#define ATMEL_MPDDRC_TP0R_TWR_MASK 0xf
> +#define ATMEL_MPDDRC_TP0R_TRC_OFFSET 12
> +#define ATMEL_MPDDRC_TP0R_TRC_MASK 0xf
> +#define ATMEL_MPDDRC_TP0R_TRP_OFFSET 16
> +#define ATMEL_MPDDRC_TP0R_TRP_MASK 0xf
> +#define ATMEL_MPDDRC_TP0R_TRRD_OFFSET 20
> +#define ATMEL_MPDDRC_TP0R_TRRD_MASK 0xf
> +#define ATMEL_MPDDRC_TP0R_TWTR_OFFSET 24
> +#define ATMEL_MPDDRC_TP0R_TWTR_MASK 0x7
> +#define ATMEL_MPDDRC_TP0R_RDC_WRRD_OFFSET 27
> +#define ATMEL_MPDDRC_TP0R_RDC_WRRD_MASK 0x1
> +#define ATMEL_MPDDRC_TP0R_TMRD_OFFSET 28
> +#define ATMEL_MPDDRC_TP0R_TMRD_MASK 0xf
> +
> +/* bit field in timing parameter 1 register */
> +#define ATMEL_MPDDRC_TP1R_TRFC_OFFSET 0
> +#define ATMEL_MPDDRC_TP1R_TRFC_MASK 0x7f
> +#define ATMEL_MPDDRC_TP1R_TXSNR_OFFSET 8
> +#define ATMEL_MPDDRC_TP1R_TXSNR_MASK 0xff
> +#define ATMEL_MPDDRC_TP1R_TXSRD_OFFSET 16
> +#define ATMEL_MPDDRC_TP1R_TXSRD_MASK 0xff
> +#define ATMEL_MPDDRC_TP1R_TXP_OFFSET 24
> +#define ATMEL_MPDDRC_TP1R_TXP_MASK 0xf
> +
> +/* bit field in timing parameter 2 register */
> +#define ATMEL_MPDDRC_TP2R_TXARD_OFFSET 0
> +#define ATMEL_MPDDRC_TP2R_TXARD_MASK 0xf
> +#define ATMEL_MPDDRC_TP2R_TXARDS_OFFSET 4
> +#define ATMEL_MPDDRC_TP2R_TXARDS_MASK 0xf
> +#define ATMEL_MPDDRC_TP2R_TRPA_OFFSET 8
> +#define ATMEL_MPDDRC_TP2R_TRPA_MASK 0xf
> +#define ATMEL_MPDDRC_TP2R_TRTP_OFFSET 12
> +#define ATMEL_MPDDRC_TP2R_TRTP_MASK 0x7
> +#define ATMEL_MPDDRC_TP2R_TFAW_OFFSET 16
> +#define ATMEL_MPDDRC_TP2R_TFAW_MASK 0xf
> +
> +/* bit field in Memory Device Register */
> +#define ATMEL_MPDDRC_MDR_LPDDR_SDRAM 0x3
> +#define ATMEL_MPDDRC_MDR_DDR2_SDRAM 0x6
> +#define ATMEL_MPDDRC_MDR_DBW_MASK (0x1 << 4)
> +#define ATMEL_MPDDRC_MDR_DBW_32BITS (0x0 << 4)
> +#define ATMEL_MPDDRC_MDR_DBW_16BITS (0x1 << 4)
> +
> +#endif
> diff --git a/spl/Makefile b/spl/Makefile
> index b366ac2..6dd1e5d 100644
> --- a/spl/Makefile
> +++ b/spl/Makefile
> @@ -123,6 +123,10 @@ ifeq ($(SOC),exynos)
> LIBS-y += $(CPUDIR)/s5p-common/libs5p-common.o
> endif
>
> +ifeq ($(SOC),at91)
> +LIBS-y += arch/$(ARCH)/cpu/at91-common/libat91-common.o
> +endif

The libat91-common.o should be built in any case. The mpddrc.o should
only be included for SPL build (that mentioned Heiko in another mail).

> +
> # Add GCC lib
> ifeq ("$(USE_PRIVATE_LIBGCC)", "yes")
> PLATFORM_LIBGCC = $(SPLTREE)/arch/$(ARCH)/lib/libgcc.o
>

Best regards

Andreas Bie?mann