[U-Boot] [PATCH v2 14/23] sunxi: H3: add DRAM controller single bit delay support

[Chen-Yu Tsai <wens@csie.org>]

On Mon, Dec 5, 2016 at 2:26 PM, Simon Glass <sjg@chromium.org> wrote:
> Hi Andre,
>
> On 4 December 2016 at 18:52, Andre Przywara <andre.przywara@arm.com> wrote:
>> From: Jens Kuske <jenskuske@gmail.com>
>>
>> Instead of setting the delay for whole bytes allow setting
>> it for each individual bit. Also add support for
>> address/command lane delays.
>>
>> Signed-off-by: Jens Kuske <jenskuske@gmail.com>
>> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
>> ---
>>  arch/arm/mach-sunxi/dram_sun8i_h3.c | 54 ++++++++++++++++++-------------------
>>  1 file changed, 27 insertions(+), 27 deletions(-)
>
> ACBDLR_WRITE_DELAY_SHIFT
>
>>
>> diff --git a/arch/arm/mach-sunxi/dram_sun8i_h3.c b/arch/arm/mach-sunxi/dram_sun8i_h3.c
>> index 3dd6803..1647d76 100644
>> --- a/arch/arm/mach-sunxi/dram_sun8i_h3.c
>> +++ b/arch/arm/mach-sunxi/dram_sun8i_h3.c
>> @@ -16,12 +16,13 @@
>>  #include <linux/kconfig.h>
>>
>>  struct dram_para {
>> -       u32 read_delays;
>> -       u32 write_delays;
>>         u16 page_size;
>>         u8 bus_width;
>>         u8 dual_rank;
>>         u8 row_bits;
>> +       const u8 dx_read_delays[4][11];
>
> Can we have #defines for 4 and 11?
>
>> +       const u8 dx_write_delays[4][11];
>> +       const u8 ac_delays[31];
>>  };
>>
>>  static inline int ns_to_t(int nanoseconds)
>> @@ -64,34 +65,25 @@ static void mctl_phy_init(u32 val)
>>         mctl_await_completion(&mctl_ctl->pgsr[0], PGSR_INIT_DONE, 0x1);
>>  }
>>
>> -static void mctl_dq_delay(u32 read, u32 write)
>> +static void mctl_set_bit_delays(struct dram_para *para)
>>  {
>>         struct sunxi_mctl_ctl_reg * const mctl_ctl =
>>                         (struct sunxi_mctl_ctl_reg *)SUNXI_DRAM_CTL0_BASE;
>>         int i, j;
>> -       u32 val;
>> -
>> -       for (i = 0; i < 4; i++) {
>> -               val = DXBDLR_WRITE_DELAY((write >> (i * 4)) & 0xf) |
>> -                     DXBDLR_READ_DELAY(((read >> (i * 4)) & 0xf) * 2);
>> -
>> -               for (j = DXBDLR_DQ(0); j <= DXBDLR_DM; j++)
>> -                       writel(val, &mctl_ctl->dx[i].bdlr[j]);
>> -       }
>>
>>         clrbits_le32(&mctl_ctl->pgcr[0], 1 << 26);
>>
>> -       for (i = 0; i < 4; i++) {
>> -               val = DXBDLR_WRITE_DELAY((write >> (16 + i * 4)) & 0xf) |
>> -                     DXBDLR_READ_DELAY((read >> (16 + i * 4)) & 0xf);
>> +       for (i = 0; i < 4; i++)
>> +               for (j = 0; j < 11; j++)
>> +                       writel(DXBDLR_WRITE_DELAY(para->dx_write_delays[i][j]) |
>> +                              DXBDLR_READ_DELAY(para->dx_read_delays[i][j]),
>> +                              &mctl_ctl->dx[i].bdlr[j]);
>>
>> -               writel(val, &mctl_ctl->dx[i].bdlr[DXBDLR_DQS]);
>> -               writel(val, &mctl_ctl->dx[i].bdlr[DXBDLR_DQSN]);
>> -       }
>> +       for (i = 0; i < 31; i++)
>> +               writel(ACBDLR_WRITE_DELAY(para->ac_delays[i]),
>> +                      &mctl_ctl->acbdlr[i]);
>>
>>         setbits_le32(&mctl_ctl->pgcr[0], 1 << 26);
>> -
>> -       udelay(1);
>>  }
>>
>>  static void mctl_set_master_priority(void)
>> @@ -372,11 +364,8 @@ static int mctl_channel_init(struct dram_para *para)
>>         clrsetbits_le32(&mctl_ctl->dtcr, 0xf << 24,
>>                         (para->dual_rank ? 0x3 : 0x1) << 24);
>>
>> -
>> -       if (para->read_delays || para->write_delays) {
>> -               mctl_dq_delay(para->read_delays, para->write_delays);
>> -               udelay(50);
>> -       }
>> +       mctl_set_bit_delays(para);
>> +       udelay(50);
>>
>>         mctl_zq_calibration(para);
>>
>> @@ -458,12 +447,23 @@ unsigned long sunxi_dram_init(void)
>>                         (struct sunxi_mctl_ctl_reg *)SUNXI_DRAM_CTL0_BASE;
>>
>>         struct dram_para para = {
>> -               .read_delays = 0x00007979,      /* dram_tpr12 */
>> -               .write_delays = 0x6aaa0000,     /* dram_tpr11 */
>>                 .dual_rank = 0,
>>                 .bus_width = 32,
>>                 .row_bits = 15,
>>                 .page_size = 4096,
>> +
>> +               .dx_read_delays =  {{ 18, 18, 18, 18, 18, 18, 18, 18, 18,  0,  0 },
>> +                                   { 14, 14, 14, 14, 14, 14, 14, 14, 14,  0,  0 },
>> +                                   { 18, 18, 18, 18, 18, 18, 18, 18, 18,  0,  0 },
>> +                                   { 14, 14, 14, 14, 14, 14, 14, 14, 14,  0,  0 }},
>> +               .dx_write_delays = {{  0,  0,  0,  0,  0,  0,  0,  0,  0, 10, 10 },
>> +                                   {  0,  0,  0,  0,  0,  0,  0,  0,  0, 10, 10 },
>> +                                   {  0,  0,  0,  0,  0,  0,  0,  0,  0, 10, 10 },
>> +                                   {  0,  0,  0,  0,  0,  0,  0,  0,  0,  6,  6 }},
>> +               .ac_delays = {  0,  0,  0,  0,  0,  0,  0,  0,
>> +                               0,  0,  0,  0,  0,  0,  0,  0,
>> +                               0,  0,  0,  0,  0,  0,  0,  0,
>> +                               0,  0,  0,  0,  0,  0,  0      },
>>         };
>>
>>         mctl_sys_init(&para);
>> --
>> 2.8.2
>>
>
> I wonder if there is value in moving this to device tree with of-platdata?

I think device tree support is unlikely to fit in SPL for sunxi.
IIRC Andre already mentions the space constraints in his cover letter.

ChenYu