Currently, we've only been minimizing the power draw while keeping the
RC up at all times. This is suboptimal, as it draws a whole lot of power
and prevents the SoC from power collapsing.
Implement full shutdown and re-initialization to allow for powering off
the controller.
This is mainly intended for SC8280XP with a broken power rail setup,
which requires a full RC shutdown/reinit in order to reach SoC-wide
power collapse, but sleeping is generally better than not sleeping and
less destructive suspend can be implemented later for platforms that
support it.
Co-developed-by: Bjorn Andersson <quic_bjorande@xxxxxxxxxxx>
Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
---
drivers/pci/controller/dwc/Kconfig | 1 +
drivers/pci/controller/dwc/pcie-qcom.c | 158 ++++++++++++++++++++++++++-------
2 files changed, 125 insertions(+), 34 deletions(-)
diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 8afacc90c63b..4ce266951cb6 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -268,6 +268,7 @@ config PCIE_DW_PLAT_EP
config PCIE_QCOM
bool "Qualcomm PCIe controller (host mode)"
depends on OF && (ARCH_QCOM || COMPILE_TEST)
+ depends on QCOM_COMMAND_DB || QCOM_COMMAND_DB=n
depends on PCI_MSI
select PCIE_DW_HOST
select CRC8
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index d875a9b2b7be..8fb3532f4651 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -30,13 +30,17 @@
#include <linux/reset.h>
#include <linux/slab.h>
#include <linux/types.h>
+#include <soc/qcom/cmd-db.h>
#include "../../pci.h"
#include "pcie-designware.h"
+#include <dt-bindings/interconnect/qcom,icc.h>
+
/* PARF registers */
#define PARF_SYS_CTRL 0x00
#define PARF_PM_CTRL 0x20
+#define PARF_PM_STTS 0x24
#define PARF_PCS_DEEMPH 0x34
#define PARF_PCS_SWING 0x38
#define PARF_PHY_CTRL 0x40
@@ -81,7 +85,10 @@
#define L1_CLK_RMV_DIS BIT(1)
/* PARF_PM_CTRL register fields */
-#define REQ_NOT_ENTR_L1 BIT(5)
+#define REQ_NOT_ENTR_L1 BIT(5) /* "Prevent L0->L1" */
+
+/* PARF_PM_STTS register fields */
+#define PM_ENTER_L23 BIT(5)
/* PARF_PCS_DEEMPH register fields */
#define PCS_DEEMPH_TX_DEEMPH_GEN1(x) FIELD_PREP(GENMASK(21, 16), x)
@@ -126,6 +133,7 @@
/* ELBI_SYS_CTRL register fields */
#define ELBI_SYS_CTRL_LT_ENABLE BIT(0)
+#define ELBI_SYS_CTRL_PME_TURNOFF_MSG BIT(4)
/* AXI_MSTR_RESP_COMP_CTRL0 register fields */
#define CFG_REMOTE_RD_REQ_BRIDGE_SIZE_2K 0x4
@@ -248,6 +256,7 @@ struct qcom_pcie {
const struct qcom_pcie_cfg *cfg;
struct dentry *debugfs;
bool suspended;
+ bool soc_is_rpmh;
};
#define to_qcom_pcie(x) dev_get_drvdata((x)->dev)
@@ -277,6 +286,24 @@ static int qcom_pcie_start_link(struct dw_pcie *pci)
return 0;
}
+static int qcom_pcie_stop_link(struct dw_pcie *pci)
+{
+ struct qcom_pcie *pcie = to_qcom_pcie(pci);
+ u32 ret_l23, val;
+
+ writel(ELBI_SYS_CTRL_PME_TURNOFF_MSG, pcie->elbi + ELBI_SYS_CTRL);
+ readl(pcie->elbi + ELBI_SYS_CTRL);
+
+ ret_l23 = readl_poll_timeout(pcie->parf + PARF_PM_STTS, val,
+ val & PM_ENTER_L23, 10000, 100000);
+ if (ret_l23) {
+ dev_err(pci->dev, "Failed to enter L2/L3\n");
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
+
static void qcom_pcie_clear_aspm_l0s(struct dw_pcie *pci)
{
struct qcom_pcie *pcie = to_qcom_pcie(pci);
@@ -1012,9 +1039,19 @@ static void qcom_pcie_host_post_init_2_7_0(struct qcom_pcie *pcie)
static void qcom_pcie_deinit_2_7_0(struct qcom_pcie *pcie)
{
struct qcom_pcie_resources_2_7_0 *res = &pcie->res.v2_7_0;
+ u32 val;
+
+ /* Disable PCIe clocks and resets */
+ val = readl(pcie->parf + PARF_PHY_CTRL);
+ val |= PHY_TEST_PWR_DOWN;
+ writel(val, pcie->parf + PARF_PHY_CTRL);
+ readl(pcie->parf + PARF_PHY_CTRL);
clk_bulk_disable_unprepare(res->num_clks, res->clks);
+ reset_control_assert(res->rst);
+ usleep_range(2000, 2500);
+
regulator_bulk_disable(ARRAY_SIZE(res->supplies), res->supplies);
}
@@ -1581,6 +1618,9 @@ static int qcom_pcie_probe(struct platform_device *pdev)
goto err_phy_exit;
}
+ /* If the soc features RPMh, cmd_db must have been prepared by now */
+ pcie->soc_is_rpmh = !cmd_db_ready();
+
qcom_pcie_icc_update(pcie);
if (pcie->mhi)
@@ -1597,58 +1637,108 @@ static int qcom_pcie_probe(struct platform_device *pdev)
return ret;
}
-static int qcom_pcie_suspend_noirq(struct device *dev)
+static int qcom_pcie_resume_noirq(struct device *dev)
{
struct qcom_pcie *pcie = dev_get_drvdata(dev);
int ret;
- /*
- * Set minimum bandwidth required to keep data path functional during
- * suspend.
- */
- ret = icc_set_bw(pcie->icc_mem, 0, kBps_to_icc(1));
- if (ret) {
- dev_err(dev, "Failed to set interconnect bandwidth: %d\n", ret);
- return ret;
+ if (pcie->soc_is_rpmh) {
+ /*
+ * Undo the tag change from qcom_pcie_suspend_noirq first in
+ * case RPMh spontaneously decides to power collapse the
+ * platform based on other inputs.
+ */
+ icc_set_tag(pcie->icc_mem, QCOM_ICC_TAG_ALWAYS);
+
+ /* Flush the tag change */
+ ret = icc_enable(pcie->icc_mem);
+ if (ret) {
+ dev_err(pcie->pci->dev, "failed to icc_enable: %d", ret);
+ return ret;
+ }
}
- /*
- * Turn OFF the resources only for controllers without active PCIe
- * devices. For controllers with active devices, the resources are kept
- * ON and the link is expected to be in L0/L1 (sub)states.
- *
- * Turning OFF the resources for controllers with active PCIe devices
- * will trigger access violation during the end of the suspend cycle,
- * as kernel tries to access the PCIe devices config space for masking
- * MSIs.
- *
- * Also, it is not desirable to put the link into L2/L3 state as that
- * implies VDD supply will be removed and the devices may go into
- * powerdown state. This will affect the lifetime of the storage devices
- * like NVMe.
- */
- if (!dw_pcie_link_up(pcie->pci)) {
- qcom_pcie_host_deinit(&pcie->pci->pp);
- pcie->suspended = true;
- }
+ /* Only check this now to make sure the icc tag has been set. */
+ if (!pcie->suspended)
+ return 0;
+
+ ret = qcom_pcie_host_init(&pcie->pci->pp);
+ if (ret)
+ goto revert_icc_tag;
+
+ dw_pcie_setup_rc(&pcie->pci->pp);
+
+ ret = qcom_pcie_start_link(pcie->pci);
+ if (ret)
+ goto deinit_host;
+
+ /* Ignore the retval, the devices may come up later. */
+ dw_pcie_wait_for_link(pcie->pci);
+
+ qcom_pcie_icc_update(pcie);
+
+ pcie->suspended = false;
return 0;
+
+deinit_host:
+ qcom_pcie_host_deinit(&pcie->pci->pp);
+revert_icc_tag:
+ if (pcie->soc_is_rpmh) {
+ icc_set_tag(pcie->icc_mem, QCOM_ICC_TAG_WAKE);
+
+ /* Ignore the retval, failing here would be tragic anyway.. */
+ icc_enable(pcie->icc_mem);
+ }
+
+ return ret;
}
-static int qcom_pcie_resume_noirq(struct device *dev)
+static int qcom_pcie_suspend_noirq(struct device *dev)
{
struct qcom_pcie *pcie = dev_get_drvdata(dev);
int ret;
- if (pcie->suspended) {
- ret = qcom_pcie_host_init(&pcie->pci->pp);
+ if (pcie->suspended)
+ return 0;
+
+ if (dw_pcie_link_up(pcie->pci)) {
+ ret = qcom_pcie_stop_link(pcie->pci);
if (ret)
return ret;
+ }
- pcie->suspended = false;
+ qcom_pcie_host_deinit(&pcie->pci->pp);
+
+ if (pcie->soc_is_rpmh) {
+ /*
+ * The PCIe RC may be covertly accessed by the secure firmware
+ * on sleep exit. Use the WAKE bucket to let RPMh pull the plug
+ * on PCIe in sleep, but guarantee it comes back up for resume.
+ */
+ icc_set_tag(pcie->icc_mem, QCOM_ICC_TAG_WAKE);
+
+ /* Flush the tag change */
+ ret = icc_enable(pcie->icc_mem);
+ if (ret) {
+ dev_err(pcie->pci->dev, "failed to icc_enable %d\n", ret);
+
+ /* Revert everything and pray icc calls succeed */
+ return qcom_pcie_resume_noirq(dev);
+ }
+ } else {
+ /*
+ * Set minimum bandwidth required to keep data path functional
+ * during suspend.
+ */
+ ret = icc_set_bw(pcie->icc_mem, 0, kBps_to_icc(1));
+ if (ret) {
+ dev_err(dev, "Failed to set interconnect bandwidth: %d\n", ret);
+ return ret;
+ }
}
- qcom_pcie_icc_update(pcie);
+ pcie->suspended = true;
return 0;
}
--
2.44.0
