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

Sebastian Reichel
2024-04-04T17:11:48Z

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);

/* 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);

--
2.43.0