From: "jian.yang" <jian.yang@xxxxxxxxxxxx>
Make MediaTek's controller driver capable of controlling power
supplies and reset pin of a downstream component in power-on and
power-off flow.
Some downstream components (e.g., a WIFI chip) may need an extra
reset pin other than PERST# and their power supplies, depending on
the requirements of platform, may need to controlled by their
parent's driver. To meet the requirements described above, I add this
feature to MediaTek's PCIe controller driver as an optional feature.
Signed-off-by: jian.yang <jian.yang@xxxxxxxxxxxx>
---
drivers/pci/controller/pcie-mediatek-gen3.c | 93 ++++++++++++++++++++-
1 file changed, 92 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
index e0e27645fdf4..ad4b25c34f5d 100644
--- a/drivers/pci/controller/pcie-mediatek-gen3.c
+++ b/drivers/pci/controller/pcie-mediatek-gen3.c
@@ -8,6 +8,7 @@
#include <linux/clk.h>
#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
#include <linux/iopoll.h>
#include <linux/irq.h>
#include <linux/irqchip/chained_irq.h>
@@ -20,6 +21,8 @@
#include <linux/platform_device.h>
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>
+#include <linux/pm_wakeup.h>
+#include <linux/regulator/consumer.h>
#include <linux/reset.h>
#include "../pci.h"
@@ -100,6 +103,13 @@
#define PCIE_ATR_TLP_TYPE_MEM PCIE_ATR_TLP_TYPE(0)
#define PCIE_ATR_TLP_TYPE_IO PCIE_ATR_TLP_TYPE(2)
+/* Downstream Component power supplies used by MediaTek PCIe */
+static const char *const dsc_power_supplies[] = {
+ "pcie1v8",
+ "pcie3v3",
+ "pcie12v",
+};
+
/**
* struct mtk_msi_set - MSI information for each set
* @base: IO mapped register base
@@ -122,6 +132,9 @@ struct mtk_msi_set {
* @phy: PHY controller block
* @clks: PCIe clocks
* @num_clks: PCIe clocks count for this port
+ * @supplies: Downstream Component power supplies
+ * @num_supplies: Downstream Component power supplies count
+ * @dsc_reset: The GPIO pin to reset Downstream component
* @irq: PCIe controller interrupt number
* @saved_irq_state: IRQ enable state saved at suspend time
* @irq_lock: lock protecting IRQ register access
@@ -141,6 +154,9 @@ struct mtk_gen3_pcie {
struct phy *phy;
struct clk_bulk_data *clks;
int num_clks;
+ struct regulator_bulk_data *supplies;
+ int num_supplies;
+ struct gpio_desc *dsc_reset;
int irq;
u32 saved_irq_state;
@@ -763,7 +779,7 @@ static int mtk_pcie_parse_port(struct mtk_gen3_pcie *pcie)
struct device *dev = pcie->dev;
struct platform_device *pdev = to_platform_device(dev);
struct resource *regs;
- int ret;
+ int ret, i;
regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pcie-mac");
if (!regs)
@@ -809,14 +825,86 @@ static int mtk_pcie_parse_port(struct mtk_gen3_pcie *pcie)
return pcie->num_clks;
}
+ pcie->num_supplies = ARRAY_SIZE(dsc_power_supplies);
+ pcie->supplies = devm_kcalloc(dev, pcie->num_supplies,
+ sizeof(*pcie->supplies),
+ GFP_KERNEL);
+ if (!pcie->supplies)
+ return -ENOMEM;
+
+ for (i = 0; i < pcie->num_supplies; i++)
+ pcie->supplies[i].supply = dsc_power_supplies[i];
+
+ ret = devm_regulator_bulk_get(dev, pcie->num_supplies, pcie->supplies);
+ if (ret)
+ return ret;
+
+ pcie->dsc_reset = devm_gpiod_get_optional(dev, "dsc-reset",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(pcie->dsc_reset)) {
+ ret = PTR_ERR(pcie->dsc_reset);
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "failed to request DSC reset gpio\n");
+
+ return ret;
+ }
+
return 0;
}
+static int mtk_pcie_dsc_power_up(struct mtk_gen3_pcie *pcie)
+{
+ struct device *dev = pcie->dev;
+ int ret;
+
+ /*
+ * Skip downstream component's power-up flow if it was kept power-on
+ * while system entered suspend state
+ */
+ if (device_wakeup_path(dev))
+ return 0;
+
+ /* Assert Downstream Component reset */
+ if (pcie->dsc_reset)
+ gpiod_set_value_cansleep(pcie->dsc_reset, 1);
+
+ ret = regulator_bulk_enable(pcie->num_supplies, pcie->supplies);
+ if (ret)
+ dev_err(dev, "failed to enable DSC power supplies: %d\n", ret);
+
+ /* De-assert Downstream Component reset */
+ if (pcie->dsc_reset)
+ gpiod_set_value_cansleep(pcie->dsc_reset, 0);
+
+ return ret;
+}
+
+static void mtk_pcie_dsc_power_down(struct mtk_gen3_pcie *pcie)
+{
+ /*
+ * Keep downstream component power-on if it need to wake up the
+ * system in suspend state
+ */
+ if (device_wakeup_path(pcie->dev))
+ return;
+
+ /* Assert Downstream Component reset */
+ if (pcie->dsc_reset)
+ gpiod_set_value_cansleep(pcie->dsc_reset, 1);
+
+ regulator_bulk_disable(pcie->num_supplies, pcie->supplies);
+}
+
static int mtk_pcie_power_up(struct mtk_gen3_pcie *pcie)
{
struct device *dev = pcie->dev;
int err;
+ /* Downstream Component power up before RC */
+ err = mtk_pcie_dsc_power_up(pcie);
+ if (err)
+ return err;
+
/* PHY power on and enable pipe clock */
reset_control_deassert(pcie->phy_reset);
@@ -855,6 +943,7 @@ static int mtk_pcie_power_up(struct mtk_gen3_pcie *pcie)
phy_exit(pcie->phy);
err_phy_init:
reset_control_assert(pcie->phy_reset);
+ mtk_pcie_dsc_power_down(pcie);
return err;
}
@@ -870,6 +959,8 @@ static void mtk_pcie_power_down(struct mtk_gen3_pcie *pcie)
phy_power_off(pcie->phy);
phy_exit(pcie->phy);
reset_control_assert(pcie->phy_reset);
+
+ mtk_pcie_dsc_power_down(pcie);
}
static int mtk_pcie_setup(struct mtk_gen3_pcie *pcie)
--
2.18.0
