[PATCH v7 08/10] PCI: imx6: Use dwc common suspend resume method
Richard Zhu
hongxing.zhu at nxp.com
Mon Nov 25 23:57:00 PST 2024
From: Frank Li <Frank.Li at nxp.com>
Call common dwc suspend/resume function. Use dwc common iATU method to
send out PME_TURN_OFF message. In Old DWC implementations,
PCIE_ATU_INHIBIT_PAYLOAD bit in iATU Ctrl2 register is reserved. So the
generic DWC implementation of sending the PME_Turn_Off message using a
dummy MMIO write cannot be used. Use previouse method to kick off
PME_TURN_OFF MSG for these platforms.
SRC(System Reset Control) interface is used to toggle 'turnoff_reset' to
send PME_TURN_OFF and since the DWC implementation is used, it is not
needed now.
Replace the imx_pcie_stop_link() and imx_pcie_host_exit() by
dw_pcie_suspend_noirq() in imx_pcie_suspend_noirq().
Since dw_pcie_suspend_noirq() already does these, see below call stack:
dw_pcie_suspend_noirq()
dw_pcie_stop_link();
imx_pcie_stop_link();
pci->pp.ops->deinit();
imx_pcie_host_exit();
Replace the imx_pcie_host_init(), dw_pcie_setup_rc() and
imx_pcie_start_link() by dw_pcie_resume_noirq() in
imx_pcie_resume_noirq().
Since dw_pcie_resume_noirq() already does these, see below call stack:
dw_pcie_resume_noirq()
pci->pp.ops->init();
imx_pcie_host_init();
dw_pcie_setup_rc();
dw_pcie_start_link();
imx_pcie_start_link();
Signed-off-by: Frank Li <Frank.Li at nxp.com>
Signed-off-by: Richard Zhu <hongxing.zhu at nxp.com>
---
drivers/pci/controller/dwc/pci-imx6.c | 96 ++++++++++-----------------
1 file changed, 35 insertions(+), 61 deletions(-)
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 743a71789d17..87dac4ac9d10 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -33,6 +33,7 @@
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>
+#include "../../pci.h"
#include "pcie-designware.h"
#define IMX8MQ_GPR_PCIE_REF_USE_PAD BIT(9)
@@ -112,19 +113,18 @@ struct imx_pcie_drvdata {
int (*init_phy)(struct imx_pcie *pcie);
int (*enable_ref_clk)(struct imx_pcie *pcie, bool enable);
int (*core_reset)(struct imx_pcie *pcie, bool assert);
+ const struct dw_pcie_host_ops *ops;
};
struct imx_pcie {
struct dw_pcie *pci;
struct gpio_desc *reset_gpiod;
- bool link_is_up;
struct clk_bulk_data clks[IMX_PCIE_MAX_CLKS];
struct regmap *iomuxc_gpr;
u16 msi_ctrl;
u32 controller_id;
struct reset_control *pciephy_reset;
struct reset_control *apps_reset;
- struct reset_control *turnoff_reset;
u32 tx_deemph_gen1;
u32 tx_deemph_gen2_3p5db;
u32 tx_deemph_gen2_6db;
@@ -903,13 +903,11 @@ static int imx_pcie_start_link(struct dw_pcie *pci)
dev_info(dev, "Link: Only Gen1 is enabled\n");
}
- imx_pcie->link_is_up = true;
tmp = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA);
dev_info(dev, "Link up, Gen%i\n", tmp & PCI_EXP_LNKSTA_CLS);
return 0;
err_reset_phy:
- imx_pcie->link_is_up = false;
dev_dbg(dev, "PHY DEBUG_R0=0x%08x DEBUG_R1=0x%08x\n",
dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG0),
dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG1));
@@ -1014,9 +1012,31 @@ static void imx_pcie_host_exit(struct dw_pcie_rp *pp)
regulator_disable(imx_pcie->vpcie);
}
+/*
+ * In Old DWC implementations, PCIE_ATU_INHIBIT_PAYLOAD bit in iATU Ctrl2
+ * register is reserved. So the generic DWC implementation of sending the
+ * PME_Turn_Off message using a dummy MMIO write cannot be used.
+ */
+static void imx_pcie_pme_turn_off(struct dw_pcie_rp *pp)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+ struct imx_pcie *imx_pcie = to_imx_pcie(pci);
+
+ regmap_set_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR12, IMX6SX_GPR12_PCIE_PM_TURN_OFF);
+ regmap_clear_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR12, IMX6SX_GPR12_PCIE_PM_TURN_OFF);
+
+ usleep_range(PCIE_PME_TO_L2_TIMEOUT_US/10, PCIE_PME_TO_L2_TIMEOUT_US);
+}
+
static const struct dw_pcie_host_ops imx_pcie_host_ops = {
.init = imx_pcie_host_init,
.deinit = imx_pcie_host_exit,
+ .pme_turn_off = imx_pcie_pme_turn_off,
+};
+
+static const struct dw_pcie_host_ops imx_pcie_host_dw_pme_ops = {
+ .init = imx_pcie_host_init,
+ .deinit = imx_pcie_host_exit,
};
static const struct dw_pcie_ops dw_pcie_ops = {
@@ -1143,43 +1163,6 @@ static int imx_add_pcie_ep(struct imx_pcie *imx_pcie,
return 0;
}
-static void imx_pcie_pm_turnoff(struct imx_pcie *imx_pcie)
-{
- struct device *dev = imx_pcie->pci->dev;
-
- /* Some variants have a turnoff reset in DT */
- if (imx_pcie->turnoff_reset) {
- reset_control_assert(imx_pcie->turnoff_reset);
- reset_control_deassert(imx_pcie->turnoff_reset);
- goto pm_turnoff_sleep;
- }
-
- /* Others poke directly at IOMUXC registers */
- switch (imx_pcie->drvdata->variant) {
- case IMX6SX:
- case IMX6QP:
- regmap_update_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR12,
- IMX6SX_GPR12_PCIE_PM_TURN_OFF,
- IMX6SX_GPR12_PCIE_PM_TURN_OFF);
- regmap_update_bits(imx_pcie->iomuxc_gpr, IOMUXC_GPR12,
- IMX6SX_GPR12_PCIE_PM_TURN_OFF, 0);
- break;
- default:
- dev_err(dev, "PME_Turn_Off not implemented\n");
- return;
- }
-
- /*
- * Components with an upstream port must respond to
- * PME_Turn_Off with PME_TO_Ack but we can't check.
- *
- * The standard recommends a 1-10ms timeout after which to
- * proceed anyway as if acks were received.
- */
-pm_turnoff_sleep:
- usleep_range(1000, 10000);
-}
-
static void imx_pcie_msi_save_restore(struct imx_pcie *imx_pcie, bool save)
{
u8 offset;
@@ -1203,7 +1186,6 @@ static void imx_pcie_msi_save_restore(struct imx_pcie *imx_pcie, bool save)
static int imx_pcie_suspend_noirq(struct device *dev)
{
struct imx_pcie *imx_pcie = dev_get_drvdata(dev);
- struct dw_pcie_rp *pp = &imx_pcie->pci->pp;
if (!(imx_pcie->drvdata->flags & IMX_PCIE_FLAG_SUPPORTS_SUSPEND))
return 0;
@@ -1218,9 +1200,7 @@ static int imx_pcie_suspend_noirq(struct device *dev)
imx_pcie_assert_core_reset(imx_pcie);
imx_pcie->drvdata->enable_ref_clk(imx_pcie, false);
} else {
- imx_pcie_pm_turnoff(imx_pcie);
- imx_pcie_stop_link(imx_pcie->pci);
- imx_pcie_host_exit(pp);
+ return dw_pcie_suspend_noirq(imx_pcie->pci);
}
return 0;
@@ -1230,7 +1210,6 @@ static int imx_pcie_resume_noirq(struct device *dev)
{
int ret;
struct imx_pcie *imx_pcie = dev_get_drvdata(dev);
- struct dw_pcie_rp *pp = &imx_pcie->pci->pp;
if (!(imx_pcie->drvdata->flags & IMX_PCIE_FLAG_SUPPORTS_SUSPEND))
return 0;
@@ -1250,17 +1229,12 @@ static int imx_pcie_resume_noirq(struct device *dev)
ret = dw_pcie_setup_rc(&imx_pcie->pci->pp);
if (ret)
return ret;
- imx_pcie_msi_save_restore(imx_pcie, false);
} else {
- ret = imx_pcie_host_init(pp);
+ ret = dw_pcie_resume_noirq(imx_pcie->pci);
if (ret)
return ret;
- imx_pcie_msi_save_restore(imx_pcie, false);
- dw_pcie_setup_rc(pp);
-
- if (imx_pcie->link_is_up)
- imx_pcie_start_link(imx_pcie->pci);
}
+ imx_pcie_msi_save_restore(imx_pcie, false);
return 0;
}
@@ -1291,11 +1265,15 @@ static int imx_pcie_probe(struct platform_device *pdev)
pci->dev = dev;
pci->ops = &dw_pcie_ops;
- pci->pp.ops = &imx_pcie_host_ops;
imx_pcie->pci = pci;
imx_pcie->drvdata = of_device_get_match_data(dev);
+ if (imx_pcie->drvdata->ops)
+ pci->pp.ops = imx_pcie->drvdata->ops;
+ else
+ pci->pp.ops = &imx_pcie_host_dw_pme_ops;
+
/* Find the PHY if one is defined, only imx7d uses it */
np = of_parse_phandle(node, "fsl,imx7d-pcie-phy", 0);
if (np) {
@@ -1368,13 +1346,6 @@ static int imx_pcie_probe(struct platform_device *pdev)
break;
}
- /* Grab turnoff reset */
- imx_pcie->turnoff_reset = devm_reset_control_get_optional_exclusive(dev, "turnoff");
- if (IS_ERR(imx_pcie->turnoff_reset)) {
- dev_err(dev, "Failed to get TURNOFF reset control\n");
- return PTR_ERR(imx_pcie->turnoff_reset);
- }
-
if (imx_pcie->drvdata->gpr) {
/* Grab GPR config register range */
imx_pcie->iomuxc_gpr =
@@ -1454,6 +1425,7 @@ static int imx_pcie_probe(struct platform_device *pdev)
if (ret < 0)
return ret;
} else {
+ pci->pp.use_atu_msg = true;
ret = dw_pcie_host_init(&pci->pp);
if (ret < 0)
return ret;
@@ -1519,6 +1491,7 @@ static const struct imx_pcie_drvdata drvdata[] = {
.init_phy = imx6sx_pcie_init_phy,
.enable_ref_clk = imx6sx_pcie_enable_ref_clk,
.core_reset = imx6sx_pcie_core_reset,
+ .ops = &imx_pcie_host_ops,
},
[IMX6QP] = {
.variant = IMX6QP,
@@ -1536,6 +1509,7 @@ static const struct imx_pcie_drvdata drvdata[] = {
.init_phy = imx_pcie_init_phy,
.enable_ref_clk = imx6q_pcie_enable_ref_clk,
.core_reset = imx6qp_pcie_core_reset,
+ .ops = &imx_pcie_host_ops,
},
[IMX7D] = {
.variant = IMX7D,
--
2.37.1
More information about the linux-arm-kernel
mailing list