[U-Boot] [PATCH] sunxi: H6: DRAM: Add support for half DQ
André Przywara
andre.przywara at arm.com
Wed Aug 21 00:31:04 UTC 2019
On 17/07/2019 23:16, Jernej Skrabec wrote:
> Half DQ configuration seems to be very rare for H6 based boards/STBs,
> but exists nevertheless. Currently the only known product which needs
> this support is Tanix TX6 mini.
>
> This commit adds support for half DQ configuration. Code was tested
> for regressions on other configurations (OrangePi 3 1 GiB/LPDDR3, Tanix
> TX6 4 GiB/DDR3) and none were found.
>
> Thanks to Icenowy Zheng for help with this code.
>
> Signed-off-by: Jernej Skrabec <jernej.skrabec at siol.net>
I don't have a board with 16-bit DRAM, but can confirm that this still
works on the PineH64 and the Eachlink H6 Mini.
Aside from the one question below, the code looks alright for me. I
verified the bits set or checked below against the Zynq register
documentation.
I didn't browse through all of the register documentation to find other
bits that possibly affect the bus width. But since the code seems to
work for Jernej, I assume that's fine.
> ---
> .../include/asm/arch-sunxi/dram_sun50i_h6.h | 1 +
> arch/arm/mach-sunxi/dram_sun50i_h6.c | 74 ++++++++++++-------
> 2 files changed, 50 insertions(+), 25 deletions(-)
>
> diff --git a/arch/arm/include/asm/arch-sunxi/dram_sun50i_h6.h b/arch/arm/include/asm/arch-sunxi/dram_sun50i_h6.h
> index 0a1da02376..49a8a66f7b 100644
> --- a/arch/arm/include/asm/arch-sunxi/dram_sun50i_h6.h
> +++ b/arch/arm/include/asm/arch-sunxi/dram_sun50i_h6.h
> @@ -315,6 +315,7 @@ struct dram_para {
> u8 cols;
> u8 rows;
> u8 ranks;
> + u8 bus_full_width;
> const u8 dx_read_delays[NR_OF_BYTE_LANES][RD_LINES_PER_BYTE_LANE];
> const u8 dx_write_delays[NR_OF_BYTE_LANES][WR_LINES_PER_BYTE_LANE];
> };
> diff --git a/arch/arm/mach-sunxi/dram_sun50i_h6.c b/arch/arm/mach-sunxi/dram_sun50i_h6.c
> index 2a8275da3a..0d65327d35 100644
> --- a/arch/arm/mach-sunxi/dram_sun50i_h6.c
> +++ b/arch/arm/mach-sunxi/dram_sun50i_h6.c
> @@ -201,6 +201,9 @@ static void mctl_set_addrmap(struct dram_para *para)
> u8 rows = para->rows;
> u8 ranks = para->ranks;
>
> + if (!para->bus_full_width)
> + cols -= 1;
> +
> /* Ranks */
> if (ranks == 2)
> mctl_ctl->addrmap[0] = rows + cols - 3;
> @@ -213,6 +216,10 @@ static void mctl_set_addrmap(struct dram_para *para)
> /* Columns */
> mctl_ctl->addrmap[2] = 0;
> switch (cols) {
> + case 7:
> + mctl_ctl->addrmap[3] = 0x1F1F1F00;
> + mctl_ctl->addrmap[4] = 0x1F1F;
> + break;
> case 8:
> mctl_ctl->addrmap[3] = 0x1F1F0000;
> mctl_ctl->addrmap[4] = 0x1F1F;
> @@ -300,13 +307,16 @@ static void mctl_com_init(struct dram_para *para)
> reg_val = 0x3f00;
> clrsetbits_le32(&mctl_com->unk_0x008, 0x3f00, reg_val);
>
> - /* TODO: half DQ, DDR4 */
> - reg_val = MSTR_BUSWIDTH_FULL | MSTR_BURST_LENGTH(8) |
> - MSTR_ACTIVE_RANKS(para->ranks);
> + /* TODO: DDR4 */
> + reg_val = MSTR_BURST_LENGTH(8) | MSTR_ACTIVE_RANKS(para->ranks);
> if (para->type == SUNXI_DRAM_TYPE_LPDDR3)
> reg_val |= MSTR_DEVICETYPE_LPDDR3;
> if (para->type == SUNXI_DRAM_TYPE_DDR3)
> reg_val |= MSTR_DEVICETYPE_DDR3 | MSTR_2TMODE;
> + if (para->bus_full_width)
> + reg_val |= MSTR_BUSWIDTH_FULL;
> + else
> + reg_val |= MSTR_BUSWIDTH_HALF;
> writel(reg_val | BIT(31), &mctl_ctl->mstr);
>
> if (para->type == SUNXI_DRAM_TYPE_LPDDR3)
> @@ -333,7 +343,10 @@ static void mctl_com_init(struct dram_para *para)
> }
> writel(reg_val, &mctl_ctl->odtcfg);
>
> - /* TODO: half DQ */
> + if (!para->bus_full_width) {
> + writel(0x0, &mctl_phy->dx[2].gcr[0]);
> + writel(0x0, &mctl_phy->dx[3].gcr[0]);
> + }
> }
>
> static void mctl_bit_delay_set(struct dram_para *para)
> @@ -514,22 +527,31 @@ static void mctl_channel_init(struct dram_para *para)
>
> if (readl(&mctl_phy->pgsr[0]) & 0x400000)
> {
> - /*
> - * Detect single rank.
> - * TODO: also detect half DQ.
> - */
> + /* 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 &&
> - (readl(&mctl_phy->dx[2].rsr[0]) & 0x3) == 2 &&
> - (readl(&mctl_phy->dx[3].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;
> }
> - else {
> - panic("This DRAM setup is currently not supported.\n");
> +
> + /* Check for dual rank and half DQ */
> + if ((readl(&mctl_phy->dx[0].rsr[0]) & 0x3) == 0 &&
> + (readl(&mctl_phy->dx[1].rsr[0]) & 0x3) == 0) {
> + para->bus_full_width = 0;
Mmh, aren't those bits always supposed to be 0 here, regardless of the
bus width? So we just confirm dual rank here? Can we actually say from
those error bits whether no errors in bits 16-31 mean them being masked
or whether that means the upper 16 bits are working fine?
Or is bus_fill_width always 1 at this point? But then we would need to
check dx[2].rsr[0] and dx[3].rsr[0], wouldn't we?
Cheers,
Andre.
> +
> + /* 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) {
> @@ -557,11 +579,8 @@ static void mctl_channel_init(struct dram_para *para)
>
> static void mctl_auto_detect_dram_size(struct dram_para *para)
> {
> - /* TODO: non-LPDDR3, half DQ */
> - /*
> - * Detect rank number by the code in mctl_channel_init. Furtherly
> - * when DQ detection is available it will also be executed there.
> - */
> + /* 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 */
> @@ -570,8 +589,9 @@ static void mctl_auto_detect_dram_size(struct dram_para *para)
> mctl_core_init(para);
>
> for (para->rows = 13; para->rows < 18; para->rows++) {
> - /* 8 banks, 8 bit per byte and 32 bit width */
> - if (mctl_mem_matches((1 << (para->rows + para->cols + 5))))
> + /* 8 banks, 8 bit per byte and 16/32 bit width */
> + if (mctl_mem_matches((1 << (para->rows + para->cols +
> + 4 + para->bus_full_width))))
> break;
> }
>
> @@ -580,18 +600,21 @@ static void mctl_auto_detect_dram_size(struct dram_para *para)
> mctl_core_init(para);
>
> for (para->cols = 8; para->cols < 11; para->cols++) {
> - /* 8 bits per byte and 32 bit width */
> - if (mctl_mem_matches(1 << (para->cols + 2)))
> + /* 8 bits per byte and 16/32 bit width */
> + if (mctl_mem_matches(1 << (para->cols + 1 +
> + para->bus_full_width)))
> break;
> }
> }
>
> unsigned long mctl_calc_size(struct dram_para *para)
> {
> - /* TODO: non-LPDDR3, half DQ */
> + u8 width = para->bus_full_width ? 4 : 2;
> +
> + /* TODO: non-(LP)DDR3 */
>
> - /* 8 banks, 32-bit (4 byte) data width */
> - return (1ULL << (para->cols + para->rows + 3)) * 4 * para->ranks;
> + /* 8 banks */
> + return (1ULL << (para->cols + para->rows + 3)) * width * para->ranks;
> }
>
> #define SUN50I_H6_LPDDR3_DX_WRITE_DELAYS \
> @@ -625,6 +648,7 @@ unsigned long sunxi_dram_init(void)
> .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,
>
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