ar71xx: qca955x pci init/reset fixes

Current ar724x code does the reset only on single pci bus, and
in case of qca9558 writes the wrong register (0x10 vs 0x0c).
This change allows the reset of second pci bus, commonly used in
Archer C7 devices, in case host controller is stuck in reset.
If the resetting controller on boot can solve any other issue it
can be enabled unconditionally by removing reset check before
ar724x_pci_hw_init is called.

Signed-off-by: Tomislav Požega <pozega.tomislav@gmail.com>
[refreshed to apply cleanly]
Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>

1 files changed, 120 insertions, 0 deletions

diff --git a/target/linux/ar71xx/patches-4.14/953-qca955x-pci-reset-fixes.patch b/target/linux/ar71xx/patches-4.14/953-qca955x-pci-reset-fixes.patch
new file mode 100644
index 0000000000..0acca2a08f
--- /dev/null
+++ b/target/linux/ar71xx/patches-4.14/953-qca955x-pci-reset-fixes.patch
@@ -0,0 +1,120 @@
+--- a/arch/mips/ath79/common.c
++++ b/arch/mips/ath79/common.c
+@@ -153,6 +153,24 @@ void ath79_device_reset_clear(u32 mask)
+ }
+ EXPORT_SYMBOL_GPL(ath79_device_reset_clear);
+ 
++void ath79_device_reset2_clear(u32 mask)
++{
++	unsigned long flags;
++	u32 reg;
++	u32 t;
++
++	if (soc_is_qca955x())
++		reg = QCA955X_RESET_REG_RESET2_MODULE;
++	else
++		panic("Reset register not defined for this SOC");
++
++	spin_lock_irqsave(&ath79_device_reset_lock, flags);
++	t = ath79_reset_rr(reg);
++	ath79_reset_wr(reg, t & ~mask);
++	spin_unlock_irqrestore(&ath79_device_reset_lock, flags);
++}
++EXPORT_SYMBOL_GPL(ath79_device_reset2_clear);
++
+ u32 ath79_device_reset_get(u32 mask)
+ {
+ 	unsigned long flags;
+--- a/arch/mips/include/asm/mach-ath79/ar71xx_regs.h
++++ b/arch/mips/include/asm/mach-ath79/ar71xx_regs.h
+@@ -411,6 +411,7 @@
+ #define QCA955X_PLL_CPU_CONFIG_REG		0x00
+ #define QCA955X_PLL_DDR_CONFIG_REG		0x04
+ #define QCA955X_PLL_CLK_CTRL_REG		0x08
++#define QCA955X_PLL_PCIE_CONFIG_REG		0x0c
+ #define QCA955X_PLL_ETH_XMII_CONTROL_REG	0x28
+ #define QCA955X_PLL_ETH_SGMII_CONTROL_REG	0x48
+ #define QCA955X_PLL_ETH_SGMII_SERDES_REG	0x4c
+@@ -565,6 +566,7 @@
+ #define QCA953X_RESET_REG_PCIE_WMAC_INT_STATUS	0xac
+ 
+ #define QCA955X_RESET_REG_RESET_MODULE		0x1c
++#define QCA955X_RESET_REG_RESET2_MODULE		0xc4
+ #define QCA955X_RESET_REG_BOOTSTRAP		0xb0
+ #define QCA955X_RESET_REG_EXT_INT_STATUS	0xac
+ 
+--- a/arch/mips/include/asm/mach-ath79/ath79.h
++++ b/arch/mips/include/asm/mach-ath79/ath79.h
+@@ -178,6 +178,7 @@ static inline u32 ath79_reset_rr(unsigne
+ 
+ void ath79_device_reset_set(u32 mask);
+ void ath79_device_reset_clear(u32 mask);
++void ath79_device_reset2_clear(u32 mask);
+ u32 ath79_device_reset_get(u32 mask);
+ 
+ void ath79_cpu_irq_init(unsigned irq_wb_chan2, unsigned irq_wb_chan3);
+--- a/arch/mips/pci/pci-ar724x.c
++++ b/arch/mips/pci/pci-ar724x.c
+@@ -335,18 +335,37 @@ static void ar724x_pci_hw_init(struct ar
+ 	int wait = 0;
+ 
+ 	/* deassert PCIe host controller and PCIe PHY reset */
+-	ath79_device_reset_clear(AR724X_RESET_PCIE);
+-	ath79_device_reset_clear(AR724X_RESET_PCIE_PHY);
++	if (soc_is_qca955x()) {
++		ath79_device_reset_clear(QCA955X_RESET_PCIE);
++		mdelay(10);
++		ath79_device_reset_clear(QCA955X_RESET_PCIE_PHY);
++		mdelay(10);
++		ath79_device_reset2_clear(QCA955X_RESET_PCIE);
++		mdelay(10);
++		ath79_device_reset2_clear(QCA955X_RESET_PCIE_PHY);
++		mdelay(10);
++	} else {
++		ath79_device_reset_clear(AR724X_RESET_PCIE);
++		ath79_device_reset_clear(AR724X_RESET_PCIE_PHY);
++	}
+ 
+ 	/* remove the reset of the PCIE PLL */
+-	ppl = ath79_pll_rr(AR724X_PLL_REG_PCIE_CONFIG);
+-	ppl &= ~AR724X_PLL_REG_PCIE_CONFIG_PPL_RESET;
+-	ath79_pll_wr(AR724X_PLL_REG_PCIE_CONFIG, ppl);
++	if (!soc_is_qca955x()) {
++		ppl = ath79_pll_rr(AR724X_PLL_REG_PCIE_CONFIG);
++		ppl &= ~AR724X_PLL_REG_PCIE_CONFIG_PPL_RESET;
++		ath79_pll_wr(AR724X_PLL_REG_PCIE_CONFIG, ppl);
++	}
+ 
+ 	/* deassert bypass for the PCIE PLL */
+-	ppl = ath79_pll_rr(AR724X_PLL_REG_PCIE_CONFIG);
+-	ppl &= ~AR724X_PLL_REG_PCIE_CONFIG_PPL_BYPASS;
+-	ath79_pll_wr(AR724X_PLL_REG_PCIE_CONFIG, ppl);
++	if (soc_is_qca955x()) {
++		ppl = ath79_pll_rr(QCA955X_PLL_PCIE_CONFIG_REG);
++		ppl &= ~AR724X_PLL_REG_PCIE_CONFIG_PPL_BYPASS;
++		ath79_pll_wr(QCA955X_PLL_PCIE_CONFIG_REG, ppl);
++	} else {
++		ppl = ath79_pll_rr(AR724X_PLL_REG_PCIE_CONFIG);
++		ppl &= ~AR724X_PLL_REG_PCIE_CONFIG_PPL_BYPASS;
++		ath79_pll_wr(AR724X_PLL_REG_PCIE_CONFIG, ppl);
++	}
+ 
+ 	/* set PCIE Application Control to ready */
+ 	app = __raw_readl(apc->ctrl_base + AR724X_PCI_REG_APP);
+@@ -422,8 +441,14 @@ static int ar724x_pci_probe(struct platf
+ 	 * Do the full PCIE Root Complex Initialization Sequence if the PCIe
+ 	 * host controller is in reset.
+ 	 */
+-	if (ath79_reset_rr(AR724X_RESET_REG_RESET_MODULE) & AR724X_RESET_PCIE)
+-		ar724x_pci_hw_init(apc);
++	if (soc_is_qca955x()) {
++		if (ath79_reset_rr(QCA955X_RESET_REG_RESET_MODULE) & QCA955X_RESET_PCIE ||
++		    ath79_reset_rr(QCA955X_RESET_REG_RESET2_MODULE) & QCA955X_RESET_PCIE)
++			ar724x_pci_hw_init(apc);
++	} else {
++		if (ath79_reset_rr(AR724X_RESET_REG_RESET_MODULE) & AR724X_RESET_PCIE)
++			ar724x_pci_hw_init(apc);
++	}
+ 
+ 	apc->link_up = ar724x_pci_check_link(apc);
+ 	if (!apc->link_up)