Re: [PATCH 1/3] phy: rockchip-snps-pcie3: fix bifurcation on rk3588

Heiko Stuebner
2024-04-04T19:38:48Z

Am Donnerstag, 4. April 2024, 19:11:26 CEST schrieb Sebastian Reichel:
> From: Michal Tomek <mtdev79b@gmail.com>
>
> So far all RK3588 boards use fully aggregated PCIe. CM3588 is one
> of the few boards using this feature and apparently it is broken.
>
> The PHY offers the following mapping options:
>
> port 0 lane 0 - always mapped to controller 0 (4L)
> port 0 lane 1 - to controller 0 or 2 (1L0)
> port 1 lane 0 - to controller 0 or 1 (2L)
> port 1 lane 1 - to controller 0, 1 or 3 (1L1)
>
> The data-lanes DT property maps these as follows:
>
> 0 = no controller (unsupported by the HW)
> 1 = 4L
> 2 = 2L
> 3 = 1L0
> 4 = 1L1
>
> That allows the following configurations with first column being the
> mainline data-lane mapping, second column being the downstream name,
> third column being PCIE3PHY_GRF_CMN_CON0 and PHP_GRF_PCIESEL register
> values and final column being the user visible lane setup:
>
> <1 1 1 1> = AGGREG = [4 0] = x4 (aggregation)
> <1 1 2 2> = NANBNB = [0 0] = x2 x2 (no bif.)
> <1 3 2 2> = NANBBI = [1 1] = x2 x1x1 (bif. of port 0)
> <1 1 2 4> = NABINB = [2 2] = x1x1 x2 (bif. of port 1)
> <1 3 2 4> = NABIBI = [3 3] = x1x1 x1x1 (bif. of both ports)
>
> The driver currently does not program PHP_GRF_PCIESEL correctly, which
> is fixed by this patch. As a side-effect the new logic is much simpler
> than the old logic.
>
> Fixes: 2e9bffc4f713 ("phy: rockchip: Support PCIe v3")
> Signed-off-by: Michal Tomek <mtdev79b@gmail.com>
> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
> ---
> drivers/phy/rockchip/phy-rockchip-snps-pcie3.c | 24 ++++++++----------------
> 1 file changed, 8 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/phy/rockchip/phy-rockchip-snps-pcie3.c b/drivers/phy/rockchip/phy-rockchip-snps-pcie3.c
> index 121e5961ce11..d5bcc9c42b28 100644
> --- a/drivers/phy/rockchip/phy-rockchip-snps-pcie3.c
> +++ b/drivers/phy/rockchip/phy-rockchip-snps-pcie3.c
> @@ -132,7 +132,7 @@ static const struct rockchip_p3phy_ops rk3568_ops = {
> static int rockchip_p3phy_rk3588_init(struct rockchip_p3phy_priv *priv)
> {
> u32 reg = 0;
> - u8 mode = 0;
> + u8 mode = RK3588_LANE_AGGREGATION; /* default */
> int ret;
>
> /* Deassert PCIe PMA output clamp mode */
> @@ -140,28 +140,20 @@ static int rockchip_p3phy_rk3588_init(struct rockchip_p3phy_priv *priv)
>
> /* Set bifurcation if needed */
> for (int i = 0; i < priv->num_lanes; i++) {
> - if (!priv->lanes[i])
> - mode |= (BIT(i) << 3);
> -
> if (priv->lanes[i] > 1)
> - mode |= (BIT(i) >> 1);
> - }
> -
> - if (!mode)
> - reg = RK3588_LANE_AGGREGATION;
> - else {
> - if (mode & (BIT(0) | BIT(1)))
> - reg |= RK3588_BIFURCATION_LANE_0_1;
> -
> - if (mode & (BIT(2) | BIT(3)))
> - reg |= RK3588_BIFURCATION_LANE_2_3;
> + mode &= ~RK3588_LANE_AGGREGATION;
> + if (priv->lanes[i] == 3)
> + mode |= RK3588_BIFURCATION_LANE_0_1;
> + if (priv->lanes[i] == 4)
> + mode |= RK3588_BIFURCATION_LANE_2_3;
> }
>
> + reg = mode;
> regmap_write(priv->phy_grf, RK3588_PCIE3PHY_GRF_CMN_CON0, (0x7<<16) | reg);

nit: instead of doing reg=mode, why not use mode directly?
i.e. (0x7<<16) | mode in the regmap_write call

other than that
Acked-by: Heiko Stuebner <heiko@sntech.de>

>
> /* Set pcie1ln_sel in PHP_GRF_PCIESEL_CON */
> if (!IS_ERR(priv->pipe_grf)) {
> - reg = (mode & (BIT(6) | BIT(7))) >> 6;
> + reg = mode & 3;
> if (reg)
> regmap_write(priv->pipe_grf, PHP_GRF_PCIESEL_CON,
> (reg << 16) | reg);
>
>