PCI: mediatek-gen3: Move reset/assert callbacks in .power_up()

In order to make the code more readable, the reset_control_bulk_assert()
function for PHY reset lines is moved to make it pair with
reset_control_bulk_deassert() in mtk_pcie_power_up() and
mtk_pcie_en7581_power_up(). The same change is done for
reset_control_assert() used to assert MAC reset line.

Introduce PCIE_MTK_RESET_TIME_US macro for the time needed to
complete PCIe reset on MediaTek controller.

Link: https://lore.kernel.org/r/20250108-pcie-en7581-fixes-v6-2-21ac939a3b9b@kernel.org
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Author: LorenzoBianconi

drivers/pci/controller/pcie-mediatek-gen3.c

@@ -125,6 +125,8 @@
 
 #define MAX_NUM_PHY_RESETS		3
 
+#define PCIE_MTK_RESET_TIME_US		10
+
 /* Time in ms needed to complete PCIe reset on EN7581 SoC */
 #define PCIE_EN7581_RESET_TIME_MS	100
 
@@ -913,9 +915,14 @@ static int mtk_pcie_en7581_power_up(struct mtk_gen3_pcie *pcie)
 	u32 val;
 
 	/*
-	 * Wait for the time needed to complete the bulk assert in
-	 * mtk_pcie_setup for EN7581 SoC.
+	 * The controller may have been left out of reset by the bootloader
+	 * so make sure that we get a clean start by asserting resets here.
 	 */
+	reset_control_bulk_assert(pcie->soc->phy_resets.num_resets,
+				  pcie->phy_resets);
+	reset_control_assert(pcie->mac_reset);
+
+	/* Wait for the time needed to complete the reset lines assert. */
 	mdelay(PCIE_EN7581_RESET_TIME_MS);
 
 	err = phy_init(pcie->phy);
@@ -982,6 +989,15 @@ static int mtk_pcie_power_up(struct mtk_gen3_pcie *pcie)
 	struct device *dev = pcie->dev;
 	int err;
 
+	/*
+	 * The controller may have been left out of reset by the bootloader
+	 * so make sure that we get a clean start by asserting resets here.
+	 */
+	reset_control_bulk_assert(pcie->soc->phy_resets.num_resets,
+				  pcie->phy_resets);
+	reset_control_assert(pcie->mac_reset);
+	usleep_range(PCIE_MTK_RESET_TIME_US, 2 * PCIE_MTK_RESET_TIME_US);
+
 	/* PHY power on and enable pipe clock */
 	err = reset_control_bulk_deassert(pcie->soc->phy_resets.num_resets, pcie->phy_resets);
 	if (err) {
@@ -1066,14 +1082,6 @@ static int mtk_pcie_setup(struct mtk_gen3_pcie *pcie)
 	 * counter since the bulk is shared.
 	 */
 	reset_control_bulk_deassert(pcie->soc->phy_resets.num_resets, pcie->phy_resets);
-	/*
-	 * The controller may have been left out of reset by the bootloader
-	 * so make sure that we get a clean start by asserting resets here.
-	 */
-	reset_control_bulk_assert(pcie->soc->phy_resets.num_resets, pcie->phy_resets);
-
-	reset_control_assert(pcie->mac_reset);
-	usleep_range(10, 20);
 
 	/* Don't touch the hardware registers before power up */
 	err = pcie->soc->power_up(pcie);