Re: [PATCH v7 18/26] PM / devfreq: rockchip-dfi: account for multiple DDRMON_CTRL registers

From: Chanwoo Choi
Date: Sun Oct 08 2023 - 18:19:15 EST


On 23. 7. 4. 18:32, Sascha Hauer wrote:
> The currently supported RK3399 has a set of registers per channel, but
> it has only a single DDRMON_CTRL register. With upcoming RK3588 this
> will be different, the RK3588 has a DDRMON_CTRL register per channel.
>
> Instead of expecting a single DDRMON_CTRL register, loop over the
> channels and write the channel specific DDRMON_CTRL register. Break
> out early out of the loop when there is only a single DDRMON_CTRL
> register like on the RK3399.
>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> Reviewed-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
> Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> ---
> drivers/devfreq/event/rockchip-dfi.c | 72 ++++++++++++++++++----------
> 1 file changed, 48 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/devfreq/event/rockchip-dfi.c b/drivers/devfreq/event/rockchip-dfi.c
> index 85ec93fd41858..2362d3953ba40 100644
> --- a/drivers/devfreq/event/rockchip-dfi.c
> +++ b/drivers/devfreq/event/rockchip-dfi.c
> @@ -113,12 +113,13 @@ struct rockchip_dfi {
> int burst_len;
> int buswidth[DMC_MAX_CHANNELS];
> int ddrmon_stride;
> + bool ddrmon_ctrl_single;
> };
>
> static int rockchip_dfi_enable(struct rockchip_dfi *dfi)
> {
> void __iomem *dfi_regs = dfi->regs;
> - int ret = 0;
> + int i, ret = 0;
>
> mutex_lock(&dfi->mutex);
>
> @@ -132,29 +133,41 @@ static int rockchip_dfi_enable(struct rockchip_dfi *dfi)
> goto out;
> }
>
> - /* clear DDRMON_CTRL setting */
> - writel_relaxed(HIWORD_UPDATE(0, DDRMON_CTRL_TIMER_CNT_EN | DDRMON_CTRL_SOFTWARE_EN |
> - DDRMON_CTRL_HARDWARE_EN), dfi_regs + DDRMON_CTRL);
> + for (i = 0; i < DMC_MAX_CHANNELS; i++) {
> + u32 ctrl = 0;
>
> - /* set ddr type to dfi */
> - switch (dfi->ddr_type) {
> - case ROCKCHIP_DDRTYPE_LPDDR2:
> - case ROCKCHIP_DDRTYPE_LPDDR3:
> - writel_relaxed(HIWORD_UPDATE(DDRMON_CTRL_LPDDR23, DDRMON_CTRL_DDR_TYPE_MASK),
> - dfi_regs + DDRMON_CTRL);
> - break;
> - case ROCKCHIP_DDRTYPE_LPDDR4:
> - case ROCKCHIP_DDRTYPE_LPDDR4X:
> - writel_relaxed(HIWORD_UPDATE(DDRMON_CTRL_LPDDR4, DDRMON_CTRL_DDR_TYPE_MASK),
> - dfi_regs + DDRMON_CTRL);
> - break;
> - default:
> - break;
> - }
> + if (!(dfi->channel_mask & BIT(i)))
> + continue;
>
> - /* enable count, use software mode */
> - writel_relaxed(HIWORD_UPDATE(DDRMON_CTRL_SOFTWARE_EN, DDRMON_CTRL_SOFTWARE_EN),
> - dfi_regs + DDRMON_CTRL);
> + /* clear DDRMON_CTRL setting */
> + writel_relaxed(HIWORD_UPDATE(0, DDRMON_CTRL_TIMER_CNT_EN |
> + DDRMON_CTRL_SOFTWARE_EN | DDRMON_CTRL_HARDWARE_EN),
> + dfi_regs + i * dfi->ddrmon_stride + DDRMON_CTRL);
> +
> + /* set ddr type to dfi */
> + switch (dfi->ddr_type) {
> + case ROCKCHIP_DDRTYPE_LPDDR2:
> + case ROCKCHIP_DDRTYPE_LPDDR3:
> + ctrl = DDRMON_CTRL_LPDDR23;
> + break;
> + case ROCKCHIP_DDRTYPE_LPDDR4:
> + case ROCKCHIP_DDRTYPE_LPDDR4X:
> + ctrl = DDRMON_CTRL_LPDDR4;
> + break;
> + default:
> + break;
> + }
> +
> + writel_relaxed(HIWORD_UPDATE(ctrl, DDRMON_CTRL_DDR_TYPE_MASK),
> + dfi_regs + i * dfi->ddrmon_stride + DDRMON_CTRL);
> +
> + /* enable count, use software mode */
> + writel_relaxed(HIWORD_UPDATE(DDRMON_CTRL_SOFTWARE_EN, DDRMON_CTRL_SOFTWARE_EN),
> + dfi_regs + i * dfi->ddrmon_stride + DDRMON_CTRL);
> +
> + if (dfi->ddrmon_ctrl_single)
> + break;
> + }
> out:
> mutex_unlock(&dfi->mutex);
>
> @@ -164,6 +177,7 @@ static int rockchip_dfi_enable(struct rockchip_dfi *dfi)
> static void rockchip_dfi_disable(struct rockchip_dfi *dfi)
> {
> void __iomem *dfi_regs = dfi->regs;
> + int i;
>
> mutex_lock(&dfi->mutex);
>
> @@ -174,8 +188,17 @@ static void rockchip_dfi_disable(struct rockchip_dfi *dfi)
> if (dfi->usecount > 0)
> goto out;
>
> - writel_relaxed(HIWORD_UPDATE(0, DDRMON_CTRL_SOFTWARE_EN),
> - dfi_regs + DDRMON_CTRL);
> + for (i = 0; i < DMC_MAX_CHANNELS; i++) {
> + if (!(dfi->channel_mask & BIT(i)))
> + continue;
> +
> + writel_relaxed(HIWORD_UPDATE(0, DDRMON_CTRL_SOFTWARE_EN),
> + dfi_regs + i * dfi->ddrmon_stride + DDRMON_CTRL);
> +
> + if (dfi->ddrmon_ctrl_single)
> + break;
> + }
> +
> clk_disable_unprepare(dfi->clk);
> out:
> mutex_unlock(&dfi->mutex);
> @@ -666,6 +689,7 @@ static int rk3399_dfi_init(struct rockchip_dfi *dfi)
> dfi->buswidth[1] = FIELD_GET(RK3399_PMUGRF_OS_REG2_BW_CH1, val) == 0 ? 4 : 2;
>
> dfi->ddrmon_stride = 0x14;
> + dfi->ddrmon_ctrl_single = true;
>
> return 0;
> };

Even if rk3568 has the only one channle and don't need to check whether 'dfi->ddrmon_ctrl_single'
is true or not because of 'if (!(dfi->channel_mask & BIT(i)))',
I recommand the add 'dfi->ddrmon_ctrl_single = true;' for rk3568 in order to
provide the number of DDRMON_CTRL reigster of rk3568.

If rk3568 doesn't have the 'ddrmon_ctrl_single', actually it is not easy
to catch what why are there no initilization for rk3568.

--
Best Regards,
Samsung Electronics
Chanwoo Choi