Re: [PATCH 3/9] sunxi: H616: dram: LPDDR4: adjust settings

[Chris Morgan <macroalpha82@gmail.com>]

On Sat, Aug 03, 2024 at 03:29:17PM +0300, Mikhail Kalashnikov wrote:
> 
> On 02.08.2024 01:55, Chris Morgan wrote:
> > From: Jernej Skrabec <jernej.skrabec@gmail.com>
> > 
> > Adjust H616 LPDDR4 DRAM settings to be in line with vendor driver.
> > 
> > Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
> > Tested-by: Chris Morgan <macromorgan@hotmail.com>
> > ---
> >   arch/arm/mach-sunxi/dram_sun50i_h616.c        | 35 +++++++++++++------
> >   .../dram_timings/h616_lpddr4_2133.c           |  2 +-
> >   2 files changed, 26 insertions(+), 11 deletions(-)
> > 
> > diff --git a/arch/arm/mach-sunxi/dram_sun50i_h616.c b/arch/arm/mach-sunxi/dram_sun50i_h616.c
> > index a20264d8b4..b6638c519e 100644
> > --- a/arch/arm/mach-sunxi/dram_sun50i_h616.c
> > +++ b/arch/arm/mach-sunxi/dram_sun50i_h616.c
> > @@ -293,14 +293,22 @@ static void mctl_phy_configure_odt(const struct dram_para *para)
> >   	dmb();
> >   }
> > -static bool mctl_phy_write_leveling(const struct dram_config *config)
> > +static bool mctl_phy_write_leveling(const struct dram_para *para,
> > +				    const struct dram_config *config)
> >   {
> >   	bool result = true;
> >   	u32 val;
> >   	clrsetbits_le32(SUNXI_DRAM_PHY0_BASE + 8, 0xc0, 0x80);
> > -	writel(4, SUNXI_DRAM_PHY0_BASE + 0xc);
> > -	writel(0x40, SUNXI_DRAM_PHY0_BASE + 0x10);
> > +
> > +	if (para->type == SUNXI_DRAM_TYPE_LPDDR4) {
> > +		/* MR2 value */
> > +		writel(0x1b, SUNXI_DRAM_PHY0_BASE + 0xc);
> > +		writel(0, SUNXI_DRAM_PHY0_BASE + 0x10);
> > +	} else {
> > +		writel(4, SUNXI_DRAM_PHY0_BASE + 0xc);
> > +		writel(0x40, SUNXI_DRAM_PHY0_BASE + 0x10);
> > +	}
> >   	setbits_le32(SUNXI_DRAM_PHY0_BASE + 8, 4);
> > @@ -859,9 +867,9 @@ static void mctl_phy_ca_bit_delay_compensation(const struct dram_para *para,
> >   		}
> >   		break;
> >   	case SUNXI_DRAM_TYPE_LPDDR4:
> > -		if (para->tpr2 & 1) {
> > -			writel(val, SUNXI_DRAM_PHY0_BASE + 0x788);
> > -		} else {
> > +		writel(val, SUNXI_DRAM_PHY0_BASE + 0x788);
> > +		if (config->ranks == 2) {
> > +			val = (para->tpr10 >> 11) & 0x1e;
> >   			writel(val, SUNXI_DRAM_PHY0_BASE + 0x794);
> >   		};
> >   		break;
> > @@ -949,6 +957,8 @@ static bool mctl_phy_init(const struct dram_para *para,
> >   		break;
> >   	case SUNXI_DRAM_TYPE_LPDDR4:
> >   		val = para->tpr6 >> 24 & 0xff;
> > +		if (!val)
> > +			val = 0x33;
> 
> We don't need this as the default value from
> arch/arm/mach-sunxi/Kconfigcovers
> this case:
> 
> config DRAM_SUN50I_H616_TPR6
> hex "H616 DRAM TPR6 parameter"
> default 0x3300c080
> 
> >   		break;
> >   	case SUNXI_DRAM_TYPE_DDR4:
> >   	default:
> > @@ -1080,19 +1090,27 @@ static bool mctl_phy_init(const struct dram_para *para,
> >   		mctl_await_completion(&mctl_ctl->mrctrl0, BIT(31), 0);
> >   		writel(0xb04, &mctl_ctl->mrctrl1);
> > +		udelay(10);
> >   		writel(0x80000030, &mctl_ctl->mrctrl0);
> > +		udelay(10);
> >   		mctl_await_completion(&mctl_ctl->mrctrl0, BIT(31), 0);
> >   		writel(0xc72, &mctl_ctl->mrctrl1);
> > +		udelay(10);
> >   		writel(0x80000030, &mctl_ctl->mrctrl0);
> > +		udelay(10);
> >   		mctl_await_completion(&mctl_ctl->mrctrl0, BIT(31), 0);
> >   		writel(0xe09, &mctl_ctl->mrctrl1);
> > +		udelay(10);
> >   		writel(0x80000030, &mctl_ctl->mrctrl0);
> > +		udelay(10);
> >   		mctl_await_completion(&mctl_ctl->mrctrl0, BIT(31), 0);
> >   		writel(0x1624, &mctl_ctl->mrctrl1);
> > +		udelay(10);
> >   		writel(0x80000030, &mctl_ctl->mrctrl0);
> > +		udelay(10);
> Looks like something experimental.

Should I remove it? Sorry but I'm not super familiar with this specific
code.

> >   		mctl_await_completion(&mctl_ctl->mrctrl0, BIT(31), 0);
> >   		break;
> >   	case SUNXI_DRAM_TYPE_DDR4:
> > @@ -1108,7 +1126,7 @@ static bool mctl_phy_init(const struct dram_para *para,
> >   	if (para->tpr10 & TPR10_WRITE_LEVELING) {
> >   		for (i = 0; i < 5; i++)
> > -			if (mctl_phy_write_leveling(config))
> > +			if (mctl_phy_write_leveling(para, config))
> >   				break;
> >   		if (i == 5) {
> >   			debug("write leveling failed!\n");
> > @@ -1234,9 +1252,6 @@ static bool mctl_ctrl_init(const struct dram_para *para,
> >   	setbits_le32(&mctl_ctl->unk_0x3180, BIT(31) | BIT(30));
> >   	setbits_le32(&mctl_ctl->unk_0x4180, BIT(31) | BIT(30));
> > -	if (para->type == SUNXI_DRAM_TYPE_LPDDR4)
> > -		setbits_le32(&mctl_ctl->dbictl, 0x1);
> > -
> 
> I have this piece of code in the opizero3 mtd dump. This condition depends
> on tpr13. Judging by the dram_para parameters, it should be performed for
> lpddr4 (and maybe ddr4) memory. According to the opizero3 dump it should
> clear all values and set BIT(2). Don't know, why I only set BIT(0) here.
> This
> may be a bug or another spl from t507 and the first version of the driver.

What would be correct here then?

> 
> >   	setbits_le32(&mctl_ctl->rfshctl3, BIT(0));
> >   	clrbits_le32(&mctl_ctl->dfimisc, BIT(0));
> > diff --git a/arch/arm/mach-sunxi/dram_timings/h616_lpddr4_2133.c b/arch/arm/mach-sunxi/dram_timings/h616_lpddr4_2133.c
> > index e6446b9180..6f5c4acbd6 100644
> > --- a/arch/arm/mach-sunxi/dram_timings/h616_lpddr4_2133.c
> > +++ b/arch/arm/mach-sunxi/dram_timings/h616_lpddr4_2133.c
> > @@ -23,7 +23,7 @@ void mctl_set_timing_params(const struct dram_para *para)
> >   	u8 trcd		= max(ns_to_t(18), 2);
> >   	u8 trc		= ns_to_t(65);
> >   	u8 txp		= max(ns_to_t(8), 2);
> > -	u8 trtp		= max(ns_to_t(8), 4);
> > +	u8 trtp		= 4;
> >   	u8 trp		= ns_to_t(21);
> >   	u8 tras		= ns_to_t(42);
> >   	u16 trefi	= ns_to_t(3904) / 32;

Thank you,
Chris