[PATCH 2/2] PCI: mediatek: handle optional reset for perstout for AN7583

[Christian Marangi <ansuelsmth@gmail.com>]

The Airoha AN7583 provide the perstout via a dedicated reset line as using
the PCIe register is not possible as it will cause glitch.

Add support for it via the additional reset name pcie-perstout[slot] and
assert/deassert on an7583 specific startup.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
 drivers/pci/controller/pcie-mediatek.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/pci/controller/pcie-mediatek.c b/drivers/pci/controller/pcie-mediatek.c
index 8b57c3d75b94..3d4de9d69407 100644
--- a/drivers/pci/controller/pcie-mediatek.c
+++ b/drivers/pci/controller/pcie-mediatek.c
@@ -175,6 +175,7 @@ struct mtk_pcie_soc {
  * @phys_base: Physical address of the I/O register base region
  * @list: port list
  * @pcie: pointer to PCIe host info
+ * @perstout_reset: pointer to port perstout reset control
  * @reset: pointer to port reset control
  * @sys_ck: pointer to transaction/data link layer clock
  * @ahb_ck: pointer to AHB slave interface operating clock for CSR access
@@ -198,6 +199,7 @@ struct mtk_pcie_port {
 	struct list_head list;
 	struct mtk_pcie *pcie;
 	struct reset_control *reset;
+	struct reset_control *perstout_reset;
 	struct clk *sys_ck;
 	struct clk *ahb_ck;
 	struct clk *axi_ck;
@@ -865,6 +867,9 @@ static int mtk_pcie_startup_port_an7583(struct mtk_pcie_port *port)
 	size = lower_32_bits(resource_size(entry->res));
 	regmap_write(pbus_regmap, args[1], GENMASK(31, __fls(size)));
 
+	reset_control_assert(port->perstout_reset);
+	reset_control_deassert(port->perstout_reset);
+
 	return mtk_pcie_startup_port_v2(port);
 }
 
@@ -1020,6 +1025,11 @@ static int mtk_pcie_parse_port(struct mtk_pcie *pcie,
 	if (PTR_ERR(port->reset) == -EPROBE_DEFER)
 		return PTR_ERR(port->reset);
 
+	snprintf(name, sizeof(name), "pcie-perstout%d", slot);
+	port->perstout_reset = devm_reset_control_get_optional_exclusive(dev, name);
+	if (PTR_ERR(port->perstout_reset) == -EPROBE_DEFER)
+		return PTR_ERR(port->perstout_reset);
+
 	/* some platforms may use default PHY setting */
 	snprintf(name, sizeof(name), "pcie-phy%d", slot);
 	port->phy = devm_phy_optional_get(dev, name);
-- 
2.53.0