[PATCH 1/3] mips: pci-mt7620: fix bridge register access

[PATCH 1/3] mips: pci-mt7620: fix bridge register access

[Shiji Yang]

Host bridge registers and PCI RC control registers have different
memory base. pcie_m32() is used to write the RC control registers
instead of bridge registers. This patch introduces bridge_m32()
and use it to operate bridge registers to fix the access issue.

Signed-off-by: Shiji Yang <yangshiji66@outlook.com>
---
 arch/mips/pci/pci-mt7620.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/arch/mips/pci/pci-mt7620.c b/arch/mips/pci/pci-mt7620.c
index 5c4bdf691..94b3c96a1 100644
--- a/arch/mips/pci/pci-mt7620.c
+++ b/arch/mips/pci/pci-mt7620.c
@@ -87,6 +87,15 @@ static inline u32 bridge_r32(unsigned reg)
 	return ioread32(bridge_base + reg);
 }
 
+static inline void bridge_m32(u32 clr, u32 set, unsigned reg)
+{
+	u32 val = bridge_r32(reg);
+
+	val &= ~clr;
+	val |= set;
+	bridge_w32(val, reg);
+}
+
 static inline void pcie_w32(u32 val, unsigned reg)
 {
 	iowrite32(val, pcie_base + reg);
@@ -228,7 +237,7 @@ static int mt7620_pci_hw_init(struct platform_device *pdev)
 	pcie_phy(0x68, 0xB4);
 
 	/* put core into reset */
-	pcie_m32(0, PCIRST, RALINK_PCI_PCICFG_ADDR);
+	bridge_m32(PCIRST, PCIRST, RALINK_PCI_PCICFG_ADDR);
 	reset_control_assert(rstpcie0);
 
 	/* disable power and all clocks */
@@ -318,7 +327,7 @@ static int mt7620_pci_probe(struct platform_device *pdev)
 	mdelay(50);
 
 	/* enable write access */
-	pcie_m32(PCIRST, 0, RALINK_PCI_PCICFG_ADDR);
+	bridge_m32(PCIRST, 0, RALINK_PCI_PCICFG_ADDR);
 	mdelay(100);
 
 	/* check if there is a card present */
@@ -340,7 +349,7 @@ static int mt7620_pci_probe(struct platform_device *pdev)
 	pcie_w32(0x06040001, RALINK_PCI0_CLASS);
 
 	/* enable interrupts */
-	pcie_m32(0, PCIINT2, RALINK_PCI_PCIENA);
+	bridge_m32(PCIINT2, PCIINT2, RALINK_PCI_PCIENA);
 
 	/* voodoo from the SDK driver */
 	pci_config_read(NULL, 0, 4, 4, &val);
-- 
2.39.5

[PATCH 2/3] mips: pci-mt7620: add more register init values

[Shiji Yang]

These missing register init values are ported from the vendor SDK.
It should have some stability enhancements. Tested on both MT7620
and MT7628.

Signed-off-by: Shiji Yang <yangshiji66@outlook.com>
---
 arch/mips/pci/pci-mt7620.c | 59 +++++++++++++++++++++++++++++---------
 1 file changed, 46 insertions(+), 13 deletions(-)

diff --git a/arch/mips/pci/pci-mt7620.c b/arch/mips/pci/pci-mt7620.c
index 94b3c96a1..81a49b05f 100644
--- a/arch/mips/pci/pci-mt7620.c
+++ b/arch/mips/pci/pci-mt7620.c
@@ -26,6 +26,8 @@
 
 #define RALINK_INT_PCIE0		4
 
+#define RALINK_SYSCFG0			0x10
+#define RALINK_SYSCFG0_XTAL40		BIT(6)
 #define RALINK_CLKCFG1			0x30
 #define RALINK_GPIOMODE			0x60
 
@@ -62,7 +64,7 @@
 
 #define PCIEPHY0_CFG			0x90
 
-#define RALINK_PCIEPHY_P0_CTL_OFFSET	0x7498
+#define RALINK_PCIEPHY_P0_CTL_OFFSET	0x7000
 #define RALINK_PCIE0_CLK_EN		BIT(26)
 
 #define BUSY				0x80000000
@@ -115,6 +117,14 @@ static inline void pcie_m32(u32 clr, u32 set, unsigned reg)
 	pcie_w32(val, reg);
 }
 
+static inline void
+pcie_phyctrl_set(unsigned offset, u32 b_start, u32 bits, u32 val)
+{
+	pcie_m32(GENMASK(b_start + bits - 1, b_start),
+		 val << b_start,
+		 RALINK_PCIEPHY_P0_CTL_OFFSET + offset);
+}
+
 static int wait_pciephy_busy(void)
 {
 	unsigned long reg_value = 0x0, retry = 0;
@@ -263,10 +273,8 @@ static int mt7620_pci_hw_init(struct platform_device *pdev)
 	return 0;
 }
 
-static int mt7628_pci_hw_init(struct platform_device *pdev)
+static void mt7628_pci_hw_init(struct platform_device *pdev)
 {
-	u32 val = 0;
-
 	/* bring the core out of reset */
 	rt_sysc_m32(BIT(16), 0, RALINK_GPIOMODE);
 	reset_control_deassert(rstpcie0);
@@ -276,14 +284,33 @@ static int mt7628_pci_hw_init(struct platform_device *pdev)
 	mdelay(100);
 
 	/* voodoo from the SDK driver */
-	pcie_m32(~0xff, 0x5, RALINK_PCIEPHY_P0_CTL_OFFSET);
-
-	pci_config_read(NULL, 0, 0x70c, 4, &val);
-	val &= ~(0xff) << 8;
-	val |= 0x50 << 8;
-	pci_config_write(NULL, 0, 0x70c, 4, val);
+	pcie_phyctrl_set(0x400, 8, 1, 0x1);
+	pcie_phyctrl_set(0x400, 9, 2, 0x0);
+	pcie_phyctrl_set(0x000, 4, 1, 0x1);
+	pcie_phyctrl_set(0x000, 5, 1, 0x0);
+	pcie_phyctrl_set(0x4ac, 16, 3, 0x3);
+
+	if (rt_sysc_r32(RALINK_SYSCFG0) & RALINK_SYSCFG0_XTAL40) {
+		pcie_phyctrl_set(0x4bc, 24,  8, 0x7d);
+		pcie_phyctrl_set(0x490, 12,  4, 0x08);
+		pcie_phyctrl_set(0x490,  6,  2, 0x01);
+		pcie_phyctrl_set(0x4c0,  0, 32, 0x1f400000);
+		pcie_phyctrl_set(0x4a4,  0, 16, 0x013d);
+		pcie_phyctrl_set(0x4a8, 16, 16, 0x74);
+		pcie_phyctrl_set(0x4a8,  0, 16, 0x74);
+	} else {
+		pcie_phyctrl_set(0x4bc, 24,  8, 0x64);
+		pcie_phyctrl_set(0x490, 12,  4, 0x0a);
+		pcie_phyctrl_set(0x490,  6,  2, 0x00);
+		pcie_phyctrl_set(0x4c0,  0, 32, 0x19000000);
+		pcie_phyctrl_set(0x4a4,  0, 16, 0x018d);
+		pcie_phyctrl_set(0x4a8, 16, 16, 0x4a);
+		pcie_phyctrl_set(0x4a8,  0, 16, 0x4a);
+	}
 
-	return 0;
+	pcie_phyctrl_set(0x498, 0, 8, 0x5);
+	pcie_phyctrl_set(0x000, 5, 1, 0x1);
+	pcie_phyctrl_set(0x000, 4, 1, 0x0);
 }
 
 static int mt7620_pci_probe(struct platform_device *pdev)
@@ -316,8 +343,7 @@ static int mt7620_pci_probe(struct platform_device *pdev)
 
 	case MT762X_SOC_MT7628AN:
 	case MT762X_SOC_MT7688:
-		if (mt7628_pci_hw_init(pdev))
-			return -1;
+		mt7628_pci_hw_init(pdev);
 		break;
 
 	default:
@@ -336,6 +362,8 @@ static int mt7620_pci_probe(struct platform_device *pdev)
 		rt_sysc_m32(RALINK_PCIE0_CLK_EN, 0, RALINK_CLKCFG1);
 		if (ralink_soc == MT762X_SOC_MT7620A)
 			rt_sysc_m32(LC_CKDRVPD, PDRV_SW_SET, PPLL_DRV);
+		else
+			pcie_phyctrl_set(0x000, 0, 32, 0x10);
 		dev_info(&pdev->dev, "PCIE0 no card, disable it(RST&CLK)\n");
 		return -1;
 	}
@@ -355,6 +383,11 @@ static int mt7620_pci_probe(struct platform_device *pdev)
 	pci_config_read(NULL, 0, 4, 4, &val);
 	pci_config_write(NULL, 0, 4, 4, val | 0x7);
 
+	pci_config_read(NULL, 0, 0x70c, 4, &val);
+	val &= ~(0xff) << 8;
+	val |= 0x50 << 8;
+	pci_config_write(NULL, 0, 0x70c, 4, val);
+
 	pci_load_of_ranges(&mt7620_controller, pdev->dev.of_node);
 	register_pci_controller(&mt7620_controller);
 
-- 
2.39.5

[PATCH 3/3] mips: pci-mt7620: rework initialization procedure

[Shiji Yang]

Move the reset operation to the common part to reduce the code
redundancy. They are actually the same and needed for all SoCs.
Disabling power and clock are unnecessary for MT7620 and will be
removed. In vendor SDK, it's used to save the power when the PCI
driver is not selected. The MT7628 GPIO pinctrl has been removed
because this should be done in device-tree. Some delay intervals
have also been increased to follow the recommendations of the SoC
SDK and datasheet. Tested on both MT7620 and MT7628.

Signed-off-by: Shiji Yang <yangshiji66@outlook.com>
---
 arch/mips/pci/pci-mt7620.c | 38 +++++++++++++-------------------------
 1 file changed, 13 insertions(+), 25 deletions(-)

diff --git a/arch/mips/pci/pci-mt7620.c b/arch/mips/pci/pci-mt7620.c
index 81a49b05f..aae844f27 100644
--- a/arch/mips/pci/pci-mt7620.c
+++ b/arch/mips/pci/pci-mt7620.c
@@ -29,7 +29,6 @@
 #define RALINK_SYSCFG0			0x10
 #define RALINK_SYSCFG0_XTAL40		BIT(6)
 #define RALINK_CLKCFG1			0x30
-#define RALINK_GPIOMODE			0x60
 
 #define PPLL_CFG1			0x9c
 #define PPLL_LD				BIT(23)
@@ -246,19 +245,6 @@ static int mt7620_pci_hw_init(struct platform_device *pdev)
 	/* Elastic buffer control */
 	pcie_phy(0x68, 0xB4);
 
-	/* put core into reset */
-	bridge_m32(PCIRST, PCIRST, RALINK_PCI_PCICFG_ADDR);
-	reset_control_assert(rstpcie0);
-
-	/* disable power and all clocks */
-	rt_sysc_m32(RALINK_PCIE0_CLK_EN, 0, RALINK_CLKCFG1);
-	rt_sysc_m32(LC_CKDRVPD, PDRV_SW_SET, PPLL_DRV);
-
-	/* bring core out of reset */
-	reset_control_deassert(rstpcie0);
-	rt_sysc_m32(0, RALINK_PCIE0_CLK_EN, RALINK_CLKCFG1);
-	mdelay(100);
-
 	if (!(rt_sysc_r32(PPLL_CFG1) & PPLL_LD)) {
 		dev_err(&pdev->dev, "pcie PLL not locked, aborting init\n");
 		reset_control_assert(rstpcie0);
@@ -275,14 +261,6 @@ static int mt7620_pci_hw_init(struct platform_device *pdev)
 
 static void mt7628_pci_hw_init(struct platform_device *pdev)
 {
-	/* bring the core out of reset */
-	rt_sysc_m32(BIT(16), 0, RALINK_GPIOMODE);
-	reset_control_deassert(rstpcie0);
-
-	/* enable the pci clk */
-	rt_sysc_m32(0, RALINK_PCIE0_CLK_EN, RALINK_CLKCFG1);
-	mdelay(100);
-
 	/* voodoo from the SDK driver */
 	pcie_phyctrl_set(0x400, 8, 1, 0x1);
 	pcie_phyctrl_set(0x400, 9, 2, 0x0);
@@ -334,6 +312,16 @@ static int mt7620_pci_probe(struct platform_device *pdev)
 	ioport_resource.start = 0;
 	ioport_resource.end = ~0;
 
+	/* reset PCIe controller */
+	reset_control_assert(rstpcie0);
+	msleep(100);
+	reset_control_deassert(rstpcie0);
+	rt_sysc_m32(0, RALINK_PCIE0_CLK_EN, RALINK_CLKCFG1);
+	msleep(100);
+
+	/* assert PERST_N pin */
+	bridge_m32(PCIRST, PCIRST, RALINK_PCI_PCICFG_ADDR);
+
 	/* bring up the pci core */
 	switch (ralink_soc) {
 	case MT762X_SOC_MT7620A:
@@ -350,11 +338,11 @@ static int mt7620_pci_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "pcie is not supported on this hardware\n");
 		return -1;
 	}
-	mdelay(50);
+	msleep(500);
 
-	/* enable write access */
+	/* deassert PERST_N pin and wait PCIe peripheral init */
 	bridge_m32(PCIRST, 0, RALINK_PCI_PCICFG_ADDR);
-	mdelay(100);
+	msleep(1000);
 
 	/* check if there is a card present */
 	if ((pcie_r32(RALINK_PCI0_STATUS) & PCIE_LINK_UP_ST) == 0) {
-- 
2.39.5

Re: [PATCH 1/3] mips: pci-mt7620: fix bridge register access

[Thomas Bogendoerfer]

On Wed, Jun 18, 2025 at 11:42:05AM +0800, Shiji Yang wrote:
> Host bridge registers and PCI RC control registers have different
> memory base. pcie_m32() is used to write the RC control registers
> instead of bridge registers. This patch introduces bridge_m32()
> and use it to operate bridge registers to fix the access issue.
> 
> Signed-off-by: Shiji Yang <yangshiji66@outlook.com>
> ---
>  arch/mips/pci/pci-mt7620.c | 15 ++++++++++++---
>  1 file changed, 12 insertions(+), 3 deletions(-)

applied to mips-next

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH 2/3] mips: pci-mt7620: add more register init values

[Thomas Bogendoerfer]

On Wed, Jun 18, 2025 at 11:42:06AM +0800, Shiji Yang wrote:
> These missing register init values are ported from the vendor SDK.
> It should have some stability enhancements. Tested on both MT7620
> and MT7628.
> 
> Signed-off-by: Shiji Yang <yangshiji66@outlook.com>
> ---
>  arch/mips/pci/pci-mt7620.c | 59 +++++++++++++++++++++++++++++---------
>  1 file changed, 46 insertions(+), 13 deletions(-)

applied to mips-next

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH 3/3] mips: pci-mt7620: rework initialization procedure

[Thomas Bogendoerfer]

On Wed, Jun 18, 2025 at 11:42:07AM +0800, Shiji Yang wrote:
> Move the reset operation to the common part to reduce the code
> redundancy. They are actually the same and needed for all SoCs.
> Disabling power and clock are unnecessary for MT7620 and will be
> removed. In vendor SDK, it's used to save the power when the PCI
> driver is not selected. The MT7628 GPIO pinctrl has been removed
> because this should be done in device-tree. Some delay intervals
> have also been increased to follow the recommendations of the SoC
> SDK and datasheet. Tested on both MT7620 and MT7628.
> 
> Signed-off-by: Shiji Yang <yangshiji66@outlook.com>
> ---
>  arch/mips/pci/pci-mt7620.c | 38 +++++++++++++-------------------------
>  1 file changed, 13 insertions(+), 25 deletions(-)

applied to mips-next

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]