Re: [PATCH v2 2/2] PCI: mediatek-gen3: Configure PBUS_CSR registers for EN7581 SoC

Manivannan Sadhasivam
2025-02-14T17:45:27Z

On Sun, Feb 02, 2025 at 08:34:24PM +0100, Lorenzo Bianconi wrote:
> Configure PBus base address and address mask to allow the hw
> to detect if a given address is on PCIE0, PCIE1 or PCIE2.
>
> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> ---
> drivers/pci/controller/pcie-mediatek-gen3.c | 30 ++++++++++++++++++++++++++++-
> 1 file changed, 29 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
> index aa24ac9aaecc749b53cfc4faf6399913d20cdbf2..9c2a592cae959de8fbe9ca5c5c2253f8eadf2c76 100644
> --- a/drivers/pci/controller/pcie-mediatek-gen3.c
> +++ b/drivers/pci/controller/pcie-mediatek-gen3.c
> @@ -15,6 +15,7 @@
> #include <linux/irqchip/chained_irq.h>
> #include <linux/irqdomain.h>
> #include <linux/kernel.h>
> +#include <linux/mfd/syscon.h>
> #include <linux/module.h>
> #include <linux/msi.h>
> #include <linux/of_device.h>
> @@ -24,6 +25,7 @@
> #include <linux/platform_device.h>
> #include <linux/pm_domain.h>
> #include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
> #include <linux/reset.h>
>
> #include "../pci.h"
> @@ -127,6 +129,13 @@
>
> #define PCIE_MTK_RESET_TIME_US 10
>
> +#define PCIE_EN7581_PBUS_ADDR(_n) (0x00 + ((_n) << 3))
> +#define PCIE_EN7581_PBUS_ADDR_MASK(_n) (0x04 + ((_n) << 3))
> +#define PCIE_EN7581_PBUS_BASE_ADDR(_n) \
> + ((_n) == 2 ? 0x28000000 : \
> + (_n) == 1 ? 0x24000000 : 0x20000000)
> +#define PCIE_EN7581_PBUS_BASE_ADDR_MASK GENMASK(31, 26)
> +
> /* Time in ms needed to complete PCIe reset on EN7581 SoC */
> #define PCIE_EN7581_RESET_TIME_MS 100
>
> @@ -931,7 +940,8 @@ static int mtk_pcie_parse_port(struct mtk_gen3_pcie *pcie)
> static int mtk_pcie_en7581_power_up(struct mtk_gen3_pcie *pcie)
> {
> struct device *dev = pcie->dev;
> - int err;
> + struct regmap *map;
> + int err, slot;
> u32 val;
>
> /*
> @@ -945,6 +955,24 @@ static int mtk_pcie_en7581_power_up(struct mtk_gen3_pcie *pcie)
> /* Wait for the time needed to complete the reset lines assert. */
> msleep(PCIE_EN7581_RESET_TIME_MS);
>
> + map = syscon_regmap_lookup_by_phandle(dev->of_node,
> + "mediatek,pbus-csr");
> + if (IS_ERR(map))
> + return PTR_ERR(map);

So this is going to regress the devicetree's that do not define this syscon
region? But I do not see any devicetree using this 'airoha,en7581-pcie'
compatible, so not sure if this is going to be an issue. Are the downstream
devicetrees used?

- Mani

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