x86: Enable PCIe controller on quark/galileo

Quark SoC holds the PCIe controller in reset following a power on.
U-Boot needs to release the PCIe controller from reset. The PCIe
controller (D23:F0/F1) will not be visible in PCI configuration
space and any access to its PCI configuration registers will cause
system hang while it is held in reset.

Enable PCIe controller per Quark firmware writer guide.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>

1 files changed, 63 insertions, 0 deletions

diff --git a/arch/x86/cpu/quark/quark.c b/arch/x86/cpu/quark/quark.c
index 2688a70..7c55d9e 100644
--- a/arch/x86/cpu/quark/quark.c
+++ b/arch/x86/cpu/quark/quark.c
@@ -73,6 +73,58 @@ static void quark_setup_bars(void)
 		       CONFIG_PCIE_ECAM_BASE | MEM_BAR_EN);
 }
 
+static void quark_pcie_early_init(void)
+{
+	u32 pcie_cfg;
+
+	/*
+	 * Step1: Assert PCIe signal PERST#
+	 *
+	 * The CPU interface to the PERST# signal is platform dependent.
+	 * Call the board-specific codes to perform this task.
+	 */
+	board_assert_perst();
+
+	/* Step2: PHY common lane reset */
+	pcie_cfg = msg_port_alt_read(MSG_PORT_SOC_UNIT, PCIE_CFG);
+	pcie_cfg |= PCIE_PHY_LANE_RST;
+	msg_port_alt_write(MSG_PORT_SOC_UNIT, PCIE_CFG, pcie_cfg);
+	/* wait 1 ms for PHY common lane reset */
+	mdelay(1);
+
+	/* Step3: PHY sideband interface reset and controller main reset */
+	pcie_cfg = msg_port_alt_read(MSG_PORT_SOC_UNIT, PCIE_CFG);
+	pcie_cfg |= (PCIE_PHY_SB_RST | PCIE_CTLR_MAIN_RST);
+	msg_port_alt_write(MSG_PORT_SOC_UNIT, PCIE_CFG, pcie_cfg);
+	/* wait 80ms for PLL to lock */
+	mdelay(80);
+
+	/* Step4: Controller sideband interface reset */
+	pcie_cfg = msg_port_alt_read(MSG_PORT_SOC_UNIT, PCIE_CFG);
+	pcie_cfg |= PCIE_CTLR_SB_RST;
+	msg_port_alt_write(MSG_PORT_SOC_UNIT, PCIE_CFG, pcie_cfg);
+	/* wait 20ms for controller sideband interface reset */
+	mdelay(20);
+
+	/* Step5: De-assert PERST# */
+	board_deassert_perst();
+
+	/* Step6: Controller primary interface reset */
+	pcie_cfg = msg_port_alt_read(MSG_PORT_SOC_UNIT, PCIE_CFG);
+	pcie_cfg |= PCIE_CTLR_PRI_RST;
+	msg_port_alt_write(MSG_PORT_SOC_UNIT, PCIE_CFG, pcie_cfg);
+
+	/* Mixer Load Lane 0 */
+	pcie_cfg = msg_port_io_read(MSG_PORT_PCIE_AFE, PCIE_RXPICTRL0_L0);
+	pcie_cfg &= ~((1 << 6) | (1 << 7));
+	msg_port_io_write(MSG_PORT_PCIE_AFE, PCIE_RXPICTRL0_L0, pcie_cfg);
+
+	/* Mixer Load Lane 1 */
+	pcie_cfg = msg_port_io_read(MSG_PORT_PCIE_AFE, PCIE_RXPICTRL0_L1);
+	pcie_cfg &= ~((1 << 6) | (1 << 7));
+	msg_port_io_write(MSG_PORT_PCIE_AFE, PCIE_RXPICTRL0_L1, pcie_cfg);
+}
+
 static void quark_enable_legacy_seg(void)
 {
 	u32 hmisc2;
@@ -106,6 +158,17 @@ int arch_cpu_init(void)
 	 */
 	quark_setup_bars();
 
+	/*
+	 * Initialize PCIe controller
+	 *
+	 * Quark SoC holds the PCIe controller in reset following a power on.
+	 * U-Boot needs to release the PCIe controller from reset. The PCIe
+	 * controller (D23:F0/F1) will not be visible in PCI configuration
+	 * space and any access to its PCI configuration registers will cause
+	 * system hang while it is held in reset.
+	 */
+	quark_pcie_early_init();
+
 	/* Turn on legacy segments (A/B/E/F) decode to system RAM */
 	quark_enable_legacy_seg();