[PATCH v1 7/9] PCI: imx6: Use dwc common suspend resume method

Richard Zhu
2024-09-24T03:59:41Z

From: Frank Li <Frank.Li@nxp.com>

Call common dwc suspend/resume function. Use dwc common iATU method to send
out PME_TURN_OFF message. Old platform such as iMX6SX and iMX6QP, iATU
CTRL2 bit 22 (PCIE_ATU_INHIBIT_PAYLOAD) are reserved. So can't send out MSG
without data by dummy MMIO write. Without PCIE_ATU_INHIBIT_PAYLOAD, MSGD
will be sent out instead of MSG. So keep old method to send PME_TURN_OFF
MSG.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
---
drivers/pci/controller/dwc/pci-imx6.c | 97 ++++++++++-----------------
1 file changed, 36 insertions(+), 61 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 5ec43d9f9784..36df439d43ae 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)
@@ -82,6 +83,7 @@ enum imx_pcie_variants {
#define IMX_PCIE_FLAG_HAS_SERDES BIT(6)
#define IMX_PCIE_FLAG_SUPPORT_64BIT BIT(7)
#define IMX_PCIE_FLAG_CPU_ADDR_FIXUP BIT(8)
+#define IMX_PCIE_FLAG_CUSTOM_PME_TURNOFF BIT(9)

#define imx_check_flag(pci, val) (pci->drvdata->flags & val)

@@ -106,19 +108,18 @@ 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;
@@ -898,13 +899,11 @@ 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));
@@ -1023,9 +1022,33 @@ static u64 imx_pcie_cpu_addr_fixup(struct dw_pcie *pcie, u64 cpu_addr)
return (cpu_addr - offset);
}

+/*
+ * Old dwc iATU ctrl2 bit 22 (PCIE_ATU_INHIBIT_PAYLOAD) are reserved. So can't
+ * send out MSG without data by dummy MMIO write. Without
+ * PCIE_ATU_INHIBIT_PAYLOAD, MSGD will be sent out. So have to keep old method
+ * to send PME_TURN_OFF MSG.
+ */
+static void imx_pcie_pm_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_pm_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 = {
@@ -1146,43 +1169,6 @@ 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;
@@ -1206,36 +1192,26 @@ 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;

imx_pcie_msi_save_restore(imx_pcie, true);
- imx_pcie_pm_turnoff(imx_pcie);
- imx_pcie_stop_link(imx_pcie->pci);
- imx_pcie_host_exit(pp);
-
- return 0;
+ return dw_pcie_suspend_noirq(imx_pcie->pci);
}

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;

- 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);

return 0;
}
@@ -1267,11 +1243,14 @@ 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);

+ pci->pp.ops = &imx_pcie_host_dw_pme_ops;
+ if (imx_pcie->drvdata->ops)
+ pci->pp.ops = imx_pcie->drvdata->ops;
+
/* Find the PHY if one is defined, only imx7d uses it */
np = of_parse_phandle(node, "fsl,imx7d-pcie-phy", 0);
if (np) {
@@ -1340,13 +1319,6 @@ 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 =
@@ -1425,6 +1397,7 @@ 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;
@@ -1488,6 +1461,7 @@ 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,
@@ -1505,6 +1479,7 @@ 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