From: Hou Zhiqiang <[email protected]>
Add PME_Turn_Off/PME_TO_Ack handshake sequence, and finally
put the PCIe controller into D3 state after the L2/L3 ready
state transition process completion.
Signed-off-by: Hou Zhiqiang <[email protected]>
---
V5:
- Fix a typo of the parameter given to function dw_pcie_setup_rc()
drivers/pci/controller/dwc/pci-layerscape.c | 382 ++++++++++++++++++-
drivers/pci/controller/dwc/pcie-designware.h | 1 +
2 files changed, 381 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/controller/dwc/pci-layerscape.c b/drivers/pci/controller/dwc/pci-layerscape.c
index 71911ca4c589..868e18b12e4a 100644
--- a/drivers/pci/controller/dwc/pci-layerscape.c
+++ b/drivers/pci/controller/dwc/pci-layerscape.c
@@ -3,13 +3,16 @@
* PCIe host controller driver for Freescale Layerscape SoCs
*
* Copyright (C) 2014 Freescale Semiconductor.
+ * Copyright 2020 NXP
*
* Author: Minghuan Lian <[email protected]>
*/
+#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/init.h>
+#include <linux/iopoll.h>
#include <linux/of_pci.h>
#include <linux/of_platform.h>
#include <linux/of_irq.h>
@@ -27,17 +30,60 @@
#define PCIE_ABSERR 0x8d0 /* Bridge Slave Error Response Register */
#define PCIE_ABSERR_SETTING 0x9401 /* Forward error of non-posted request */
+/* PF Message Command Register */
+#define LS_PCIE_PF_MCR 0x2c
+#define PF_MCR_PTOMR BIT(0)
+#define PF_MCR_EXL2S BIT(1)
+
+/* LS1021A PEXn PM Write Control Register */
+#define SCFG_PEXPMWRCR(idx) (0x5c + (idx) * 0x64)
+#define PMXMTTURNOFF BIT(31)
+#define SCFG_PEXSFTRSTCR 0x190
+#define PEXSR(idx) BIT(idx)
+
+/* LS1043A PEX PME control register */
+#define SCFG_PEXPMECR 0x144
+#define PEXPME(idx) BIT(31 - (idx) * 4)
+
+/* LS1043A PEX LUT debug register */
+#define LS_PCIE_LDBG 0x7fc
+#define LDBG_SR BIT(30)
+#define LDBG_WE BIT(31)
+
#define PCIE_IATU_NUM 6
+#define LS_PCIE_IS_L2(v) \
+ (((v) & PORT_LOGIC_LTSSM_STATE_MASK) == PORT_LOGIC_LTSSM_STATE_L2)
+
+struct ls_pcie;
+
+struct ls_pcie_host_pm_ops {
+ int (*pm_init)(struct ls_pcie *pcie);
+ void (*send_turn_off_message)(struct ls_pcie *pcie);
+ void (*exit_from_l2)(struct ls_pcie *pcie);
+};
+
struct ls_pcie_drvdata {
+ const u32 pf_off;
+ const u32 lut_off;
const struct dw_pcie_host_ops *ops;
+ const struct ls_pcie_host_pm_ops *pm_ops;
};
struct ls_pcie {
struct dw_pcie *pci;
const struct ls_pcie_drvdata *drvdata;
+ void __iomem *pf_base;
+ void __iomem *lut_base;
+ bool big_endian;
+ bool ep_presence;
+ bool pm_support;
+ struct regmap *scfg;
+ int index;
};
+#define ls_pcie_lut_readl_addr(addr) ls_pcie_lut_readl(pcie, addr)
+#define ls_pcie_pf_readl_addr(addr) ls_pcie_pf_readl(pcie, addr)
#define to_ls_pcie(x) dev_get_drvdata((x)->dev)
static bool ls_pcie_is_bridge(struct ls_pcie *pcie)
@@ -78,6 +124,210 @@ static void ls_pcie_fix_error_response(struct ls_pcie *pcie)
iowrite32(PCIE_ABSERR_SETTING, pci->dbi_base + PCIE_ABSERR);
}
+static u32 ls_pcie_lut_readl(struct ls_pcie *pcie, u32 off)
+{
+ if (pcie->big_endian)
+ return ioread32be(pcie->lut_base + off);
+
+ return ioread32(pcie->lut_base + off);
+}
+
+static void ls_pcie_lut_writel(struct ls_pcie *pcie, u32 off, u32 val)
+{
+ if (pcie->big_endian)
+ return iowrite32be(val, pcie->lut_base + off);
+
+ return iowrite32(val, pcie->lut_base + off);
+
+}
+
+static u32 ls_pcie_pf_readl(struct ls_pcie *pcie, u32 off)
+{
+ if (pcie->big_endian)
+ return ioread32be(pcie->pf_base + off);
+
+ return ioread32(pcie->pf_base + off);
+}
+
+static void ls_pcie_pf_writel(struct ls_pcie *pcie, u32 off, u32 val)
+{
+ if (pcie->big_endian)
+ return iowrite32be(val, pcie->pf_base + off);
+
+ return iowrite32(val, pcie->pf_base + off);
+
+}
+
+static void ls_pcie_send_turnoff_msg(struct ls_pcie *pcie)
+{
+ u32 val;
+ int ret;
+
+ val = ls_pcie_pf_readl(pcie, LS_PCIE_PF_MCR);
+ val |= PF_MCR_PTOMR;
+ ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val);
+
+ ret = readx_poll_timeout(ls_pcie_pf_readl_addr, LS_PCIE_PF_MCR,
+ val, !(val & PF_MCR_PTOMR), 100, 10000);
+ if (ret)
+ dev_info(pcie->pci->dev, "poll turn off message timeout\n");
+}
+
+static void ls1021a_pcie_send_turnoff_msg(struct ls_pcie *pcie)
+{
+ u32 val;
+
+ if (!pcie->scfg) {
+ dev_dbg(pcie->pci->dev, "SYSCFG is NULL\n");
+ return;
+ }
+
+ /* Send Turn_off message */
+ regmap_read(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), &val);
+ val |= PMXMTTURNOFF;
+ regmap_write(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), val);
+
+ mdelay(10);
+
+ /* Clear Turn_off message */
+ regmap_read(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), &val);
+ val &= ~PMXMTTURNOFF;
+ regmap_write(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), val);
+}
+
+static void ls1043a_pcie_send_turnoff_msg(struct ls_pcie *pcie)
+{
+ u32 val;
+
+ if (!pcie->scfg) {
+ dev_dbg(pcie->pci->dev, "SYSCFG is NULL\n");
+ return;
+ }
+
+ /* Send Turn_off message */
+ regmap_read(pcie->scfg, SCFG_PEXPMECR, &val);
+ val |= PEXPME(pcie->index);
+ regmap_write(pcie->scfg, SCFG_PEXPMECR, val);
+
+ mdelay(10);
+
+ /* Clear Turn_off message */
+ regmap_read(pcie->scfg, SCFG_PEXPMECR, &val);
+ val &= ~PEXPME(pcie->index);
+ regmap_write(pcie->scfg, SCFG_PEXPMECR, val);
+}
+
+static void ls_pcie_exit_from_l2(struct ls_pcie *pcie)
+{
+ u32 val;
+ int ret;
+
+ val = ls_pcie_pf_readl(pcie, LS_PCIE_PF_MCR);
+ val |= PF_MCR_EXL2S;
+ ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val);
+
+ ret = readx_poll_timeout(ls_pcie_pf_readl_addr, LS_PCIE_PF_MCR,
+ val, !(val & PF_MCR_EXL2S), 100, 10000);
+ if (ret)
+ dev_info(pcie->pci->dev, "poll exit L2 state timeout\n");
+}
+
+static void ls_pcie_retrain_link(struct ls_pcie *pcie)
+{
+ struct dw_pcie *pci = pcie->pci;
+ u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+ u32 val;
+
+ val = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKCTL);
+ val |= PCI_EXP_LNKCTL_RL;
+ dw_pcie_writew_dbi(pci, offset + PCI_EXP_LNKCTL, val);
+}
+
+static void ls1021a_pcie_exit_from_l2(struct ls_pcie *pcie)
+{
+ u32 val;
+
+ regmap_read(pcie->scfg, SCFG_PEXSFTRSTCR, &val);
+ val |= PEXSR(pcie->index);
+ regmap_write(pcie->scfg, SCFG_PEXSFTRSTCR, val);
+
+ regmap_read(pcie->scfg, SCFG_PEXSFTRSTCR, &val);
+ val &= ~PEXSR(pcie->index);
+ regmap_write(pcie->scfg, SCFG_PEXSFTRSTCR, val);
+
+ mdelay(1);
+
+ ls_pcie_retrain_link(pcie);
+}
+static void ls1043a_pcie_exit_from_l2(struct ls_pcie *pcie)
+{
+ u32 val;
+
+ val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
+ val |= LDBG_WE;
+ ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
+
+ val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
+ val |= LDBG_SR;
+ ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
+
+ val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
+ val &= ~LDBG_SR;
+ ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
+
+ val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
+ val &= ~LDBG_WE;
+ ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
+
+ mdelay(1);
+
+ ls_pcie_retrain_link(pcie);
+}
+
+static int ls1021a_pcie_pm_init(struct ls_pcie *pcie)
+{
+ struct device *dev = pcie->pci->dev;
+ u32 index[2];
+ int ret;
+
+ pcie->scfg = syscon_regmap_lookup_by_phandle(dev->of_node,
+ "fsl,pcie-scfg");
+ if (IS_ERR(pcie->scfg)) {
+ ret = PTR_ERR(pcie->scfg);
+ dev_err(dev, "No syscfg phandle specified\n");
+ pcie->scfg = NULL;
+ return ret;
+ }
+
+ ret = of_property_read_u32_array(dev->of_node, "fsl,pcie-scfg",
+ index, 2);
+ if (ret) {
+ pcie->scfg = NULL;
+ return ret;
+ }
+
+ pcie->index = index[1];
+
+ return 0;
+}
+
+static int ls_pcie_pm_init(struct ls_pcie *pcie)
+{
+ return 0;
+}
+
+static void ls_pcie_set_dstate(struct ls_pcie *pcie, u32 dstate)
+{
+ struct dw_pcie *pci = pcie->pci;
+ u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_PM);
+ u32 val;
+
+ val = dw_pcie_readw_dbi(pci, offset + PCI_PM_CTRL);
+ val &= ~PCI_PM_CTRL_STATE_MASK;
+ val |= dstate;
+ dw_pcie_writew_dbi(pci, offset + PCI_PM_CTRL, val);
+}
+
static int ls_pcie_host_init(struct pcie_port *pp)
{
struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
@@ -91,22 +341,63 @@ static int ls_pcie_host_init(struct pcie_port *pp)
ls_pcie_drop_msg_tlp(pcie);
+ if (dw_pcie_link_up(pci)) {
+ dev_dbg(pci->dev, "Endpoint is present\n");
+ pcie->ep_presence = true;
+ }
+
+ if (pcie->drvdata->pm_ops && pcie->drvdata->pm_ops->pm_init &&
+ !pcie->drvdata->pm_ops->pm_init(pcie))
+ pcie->pm_support = true;
+
return 0;
}
+static struct ls_pcie_host_pm_ops ls1021a_pcie_host_pm_ops = {
+ .pm_init = &ls1021a_pcie_pm_init,
+ .send_turn_off_message = &ls1021a_pcie_send_turnoff_msg,
+ .exit_from_l2 = &ls1021a_pcie_exit_from_l2,
+};
+
+static struct ls_pcie_host_pm_ops ls1043a_pcie_host_pm_ops = {
+ .pm_init = &ls1021a_pcie_pm_init,
+ .send_turn_off_message = &ls1043a_pcie_send_turnoff_msg,
+ .exit_from_l2 = &ls1043a_pcie_exit_from_l2,
+};
+
+static struct ls_pcie_host_pm_ops ls_pcie_host_pm_ops = {
+ .pm_init = &ls_pcie_pm_init,
+ .send_turn_off_message = &ls_pcie_send_turnoff_msg,
+ .exit_from_l2 = &ls_pcie_exit_from_l2,
+};
+
static const struct dw_pcie_host_ops ls_pcie_host_ops = {
.host_init = ls_pcie_host_init,
};
+static const struct ls_pcie_drvdata ls1021a_drvdata = {
+ .ops = &ls_pcie_host_ops,
+ .pm_ops = &ls1021a_pcie_host_pm_ops,
+};
+
+static const struct ls_pcie_drvdata ls1043a_drvdata = {
+ .ops = &ls_pcie_host_ops,
+ .lut_off = 0x10000,
+ .pm_ops = &ls1043a_pcie_host_pm_ops,
+};
+
static const struct ls_pcie_drvdata layerscape_drvdata = {
.ops = &ls_pcie_host_ops,
+ .lut_off = 0x80000,
+ .pf_off = 0xc0000,
+ .pm_ops = &ls_pcie_host_pm_ops,
};
static const struct of_device_id ls_pcie_of_match[] = {
{ .compatible = "fsl,ls1012a-pcie", .data = &layerscape_drvdata },
- { .compatible = "fsl,ls1021a-pcie", .data = &layerscape_drvdata },
+ { .compatible = "fsl,ls1021a-pcie", .data = &ls1021a_drvdata },
{ .compatible = "fsl,ls1028a-pcie", .data = &layerscape_drvdata },
- { .compatible = "fsl,ls1043a-pcie", .data = &layerscape_drvdata },
+ { .compatible = "fsl,ls1043a-pcie", .data = &ls1043a_drvdata },
{ .compatible = "fsl,ls1046a-pcie", .data = &layerscape_drvdata },
{ .compatible = "fsl,ls2080a-pcie", .data = &layerscape_drvdata },
{ .compatible = "fsl,ls2085a-pcie", .data = &layerscape_drvdata },
@@ -142,6 +433,14 @@ static int ls_pcie_probe(struct platform_device *pdev)
if (IS_ERR(pci->dbi_base))
return PTR_ERR(pci->dbi_base);
+ pcie->big_endian = of_property_read_bool(dev->of_node, "big-endian");
+
+ if (pcie->drvdata->lut_off)
+ pcie->lut_base = pci->dbi_base + pcie->drvdata->lut_off;
+
+ if (pcie->drvdata->pf_off)
+ pcie->pf_base = pci->dbi_base + pcie->drvdata->pf_off;
+
if (!ls_pcie_is_bridge(pcie))
return -ENODEV;
@@ -150,12 +449,91 @@ static int ls_pcie_probe(struct platform_device *pdev)
return dw_pcie_host_init(&pci->pp);
}
+static bool ls_pcie_pm_check(struct ls_pcie *pcie)
+{
+ if (!pcie->ep_presence) {
+ dev_dbg(pcie->pci->dev, "Endpoint isn't present\n");
+ return false;
+ }
+
+ if (!pcie->pm_support)
+ return false;
+
+ return true;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int ls_pcie_suspend_noirq(struct device *dev)
+{
+ struct ls_pcie *pcie = dev_get_drvdata(dev);
+ struct dw_pcie *pci = pcie->pci;
+ u32 val;
+ int ret;
+
+ if (!ls_pcie_pm_check(pcie))
+ return 0;
+
+ pcie->drvdata->pm_ops->send_turn_off_message(pcie);
+
+ /* 10ms timeout to check L2 ready */
+ ret = readl_poll_timeout(pci->dbi_base + PCIE_PORT_DEBUG0,
+ val, LS_PCIE_IS_L2(val), 100, 10000);
+ if (ret) {
+ dev_err(dev, "PCIe link enter L2 timeout! ltssm = 0x%x\n", val);
+ return ret;
+ }
+
+ ls_pcie_set_dstate(pcie, 0x3);
+
+ return 0;
+}
+
+static int ls_pcie_resume_noirq(struct device *dev)
+{
+ struct ls_pcie *pcie = dev_get_drvdata(dev);
+ struct dw_pcie *pci = pcie->pci;
+ int ret;
+
+ if (!ls_pcie_pm_check(pcie))
+ return 0;
+
+ ls_pcie_set_dstate(pcie, 0x0);
+
+ pcie->drvdata->pm_ops->exit_from_l2(pcie);
+
+ dw_pcie_setup_rc(&pci->pp);
+
+ /* delay 10 ms to access EP */
+ mdelay(10);
+
+ ret = ls_pcie_host_init(&pci->pp);
+ if (ret) {
+ dev_err(dev, "ls_pcie_host_init failed! ret = 0x%x\n", ret);
+ return ret;
+ }
+
+ ret = dw_pcie_wait_for_link(pci);
+ if (ret) {
+ dev_err(dev, "wait link up timeout! ret = 0x%x\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct dev_pm_ops ls_pcie_pm_ops = {
+ SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(ls_pcie_suspend_noirq,
+ ls_pcie_resume_noirq)
+};
+
static struct platform_driver ls_pcie_driver = {
.probe = ls_pcie_probe,
.driver = {
.name = "layerscape-pcie",
.of_match_table = ls_pcie_of_match,
.suppress_bind_attrs = true,
+ .pm = &ls_pcie_pm_ops,
},
};
builtin_platform_driver(ls_pcie_driver);
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 7247c8b01f04..067b48a07100 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -54,6 +54,7 @@
#define PCIE_PORT_DEBUG0 0x728
#define PORT_LOGIC_LTSSM_STATE_MASK 0x1f
#define PORT_LOGIC_LTSSM_STATE_L0 0x11
+#define PORT_LOGIC_LTSSM_STATE_L2 0x15
#define PCIE_PORT_DEBUG1 0x72C
#define PCIE_PORT_DEBUG1_LINK_UP BIT(4)
#define PCIE_PORT_DEBUG1_LINK_IN_TRAINING BIT(29)
--
2.17.1
On Tue, Apr 6, 2021 at 10:04 PM Zhiqiang Hou <[email protected]> wrote:
>
> From: Hou Zhiqiang <[email protected]>
>
> Add PME_Turn_Off/PME_TO_Ack handshake sequence, and finally
> put the PCIe controller into D3 state after the L2/L3 ready
> state transition process completion.
>
> Signed-off-by: Hou Zhiqiang <[email protected]>
> ---
> V5:
> - Fix a typo of the parameter given to function dw_pcie_setup_rc()
>
> drivers/pci/controller/dwc/pci-layerscape.c | 382 ++++++++++++++++++-
> drivers/pci/controller/dwc/pcie-designware.h | 1 +
> 2 files changed, 381 insertions(+), 2 deletions(-)
Reviewed-by: Rob Herring <[email protected]>
Hi,
[...]
> +/* PF Message Command Register */
> +#define LS_PCIE_PF_MCR 0x2c
> +#define PF_MCR_PTOMR BIT(0)
> +#define PF_MCR_EXL2S BIT(1)
> +
> +/* LS1021A PEXn PM Write Control Register */
> +#define SCFG_PEXPMWRCR(idx) (0x5c + (idx) * 0x64)
> +#define PMXMTTURNOFF BIT(31)
> +#define SCFG_PEXSFTRSTCR 0x190
> +#define PEXSR(idx) BIT(idx)
> +
> +/* LS1043A PEX PME control register */
> +#define SCFG_PEXPMECR 0x144
> +#define PEXPME(idx) BIT(31 - (idx) * 4)
> +
> +/* LS1043A PEX LUT debug register */
> +#define LS_PCIE_LDBG 0x7fc
> +#define LDBG_SR BIT(30)
> +#define LDBG_WE BIT(31)
A small nitpick: a consistent capitalisation of "control" and "debug", and
"register" in the comments above.
[...]
> +static void ls_pcie_lut_writel(struct ls_pcie *pcie, u32 off, u32 val)
> +{
> + if (pcie->big_endian)
> + return iowrite32be(val, pcie->lut_base + off);
> +
> + return iowrite32(val, pcie->lut_base + off);
> +
> +}
Surplus newline above after the return statement.
[...]
> +static void ls_pcie_pf_writel(struct ls_pcie *pcie, u32 off, u32 val)
> +{
> + if (pcie->big_endian)
> + return iowrite32be(val, pcie->pf_base + off);
> +
> + return iowrite32(val, pcie->pf_base + off);
> +
> +}
Surplus newline above after the return statement.
[...]
> +static void ls_pcie_send_turnoff_msg(struct ls_pcie *pcie)
> +{
> + u32 val;
> + int ret;
> +
> + val = ls_pcie_pf_readl(pcie, LS_PCIE_PF_MCR);
> + val |= PF_MCR_PTOMR;
> + ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val);
> +
> + ret = readx_poll_timeout(ls_pcie_pf_readl_addr, LS_PCIE_PF_MCR,
> + val, !(val & PF_MCR_PTOMR), 100, 10000);
> + if (ret)
> + dev_info(pcie->pci->dev, "poll turn off message timeout\n");
> +}
Would this dev_info() be more of a warning or an error? A timeout is
potentially a problem, correct?
[...]
> +static void ls1021a_pcie_send_turnoff_msg(struct ls_pcie *pcie)
> +{
> + u32 val;
> +
> + if (!pcie->scfg) {
> + dev_dbg(pcie->pci->dev, "SYSCFG is NULL\n");
> + return;
> + }
> +
> + /* Send Turn_off message */
> + regmap_read(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), &val);
> + val |= PMXMTTURNOFF;
> + regmap_write(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), val);
> +
> + mdelay(10);
We often, customary, document why a particular mdelay() is needed. You
also did this in other part of the code, so perhaps adding a note here (and
everywhere else) would be nice for keeping the consistency.
[...]
> +static void ls_pcie_exit_from_l2(struct ls_pcie *pcie)
> +{
> + u32 val;
> + int ret;
> +
> + val = ls_pcie_pf_readl(pcie, LS_PCIE_PF_MCR);
> + val |= PF_MCR_EXL2S;
> + ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val);
> +
> + ret = readx_poll_timeout(ls_pcie_pf_readl_addr, LS_PCIE_PF_MCR,
> + val, !(val & PF_MCR_EXL2S), 100, 10000);
> + if (ret)
> + dev_info(pcie->pci->dev, "poll exit L2 state timeout\n");
> +}
Similarly to the question above: is this timeout something more severe and
would warrant a warning or an error here instead?
[...]
> +static void ls1021a_pcie_exit_from_l2(struct ls_pcie *pcie)
> +{
> + u32 val;
> +
> + regmap_read(pcie->scfg, SCFG_PEXSFTRSTCR, &val);
> + val |= PEXSR(pcie->index);
> + regmap_write(pcie->scfg, SCFG_PEXSFTRSTCR, val);
> +
> + regmap_read(pcie->scfg, SCFG_PEXSFTRSTCR, &val);
> + val &= ~PEXSR(pcie->index);
> + regmap_write(pcie->scfg, SCFG_PEXSFTRSTCR, val);
> +
> + mdelay(1);
Aside of documenting this mdelay() here, if possible, would 1 be enough?
Everywhere else you seem to use 10 consistently.
> +
> + ls_pcie_retrain_link(pcie);
> +}
> +static void ls1043a_pcie_exit_from_l2(struct ls_pcie *pcie)
Missing newline above to separate code blocks.
> +{
> + u32 val;
> +
> + val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
> + val |= LDBG_WE;
> + ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
> +
> + val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
> + val |= LDBG_SR;
> + ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
> +
> + val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
> + val &= ~LDBG_SR;
> + ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
> +
> + val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
> + val &= ~LDBG_WE;
> + ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
> +
> + mdelay(1);
See comment above.
[...]
> +static int ls1021a_pcie_pm_init(struct ls_pcie *pcie)
> +{
> + struct device *dev = pcie->pci->dev;
> + u32 index[2];
> + int ret;
> +
> + pcie->scfg = syscon_regmap_lookup_by_phandle(dev->of_node,
> + "fsl,pcie-scfg");
> + if (IS_ERR(pcie->scfg)) {
> + ret = PTR_ERR(pcie->scfg);
> + dev_err(dev, "No syscfg phandle specified\n");
> + pcie->scfg = NULL;
> + return ret;
> + }
> +
> + ret = of_property_read_u32_array(dev->of_node, "fsl,pcie-scfg",
> + index, 2);
> + if (ret) {
> + pcie->scfg = NULL;
> + return ret;
> + }
> +
> + pcie->index = index[1];
> +
> + return 0;
> +}
Just an idea: what about using goto for error handling?
(...)
if (IS_ERR(pcie->scfg)) {
ret = PTR_ERR(pcie->scfg);
dev_err(dev, "No syscfg phandle specified\n");
goto error;
}
ret = of_property_read_u32_array(dev->of_node, "fsl,pcie-scfg",
index, 2);
if (ret)
goto error;
pcie->index = index[1];
return 0;
error:
pcie->scfg = NULL;
return ret;
}
Not necessarily better or worse compared with your version, so it would be
more of a matter of personal preference here.
> +static int ls_pcie_suspend_noirq(struct device *dev)
> +{
> + struct ls_pcie *pcie = dev_get_drvdata(dev);
> + struct dw_pcie *pci = pcie->pci;
> + u32 val;
> + int ret;
> +
> + if (!ls_pcie_pm_check(pcie))
> + return 0;
> +
> + pcie->drvdata->pm_ops->send_turn_off_message(pcie);
> +
> + /* 10ms timeout to check L2 ready */
> + ret = readl_poll_timeout(pci->dbi_base + PCIE_PORT_DEBUG0,
> + val, LS_PCIE_IS_L2(val), 100, 10000);
> + if (ret) {
> + dev_err(dev, "PCIe link enter L2 timeout! ltssm = 0x%x\n", val);
> + return ret;
> + }
The error message above could be improve to be more like an error stating
that something failed and such, as currently it looks like a debug message,
unless it was intended as such.
[...]
> +static int ls_pcie_resume_noirq(struct device *dev)
> +{
> + struct ls_pcie *pcie = dev_get_drvdata(dev);
> + struct dw_pcie *pci = pcie->pci;
> + int ret;
> +
> + if (!ls_pcie_pm_check(pcie))
> + return 0;
> +
> + ls_pcie_set_dstate(pcie, 0x0);
> +
> + pcie->drvdata->pm_ops->exit_from_l2(pcie);
> +
> + dw_pcie_setup_rc(&pci->pp);
> +
> + /* delay 10 ms to access EP */
> + mdelay(10);
> +
> + ret = ls_pcie_host_init(&pci->pp);
> + if (ret) {
> + dev_err(dev, "ls_pcie_host_init failed! ret = 0x%x\n", ret);
> + return ret;
> + }
A small nitpick: error messages that are directed at end users should have
a little more context than just the function name.
Krzysztof
Hi Krzysztof,
Thanks a lot for your comments!
> -----Original Message-----
> From: Krzysztof Wilczyński [mailto:[email protected]]
> Sent: 2021年11月12日 8:37
> To: Z.Q. Hou <[email protected]>
> Cc: [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]; Leo Li <[email protected]>;
> [email protected]; M.H. Lian <[email protected]>;
> Mingkai Hu <[email protected]>; Roy Zang <[email protected]>
> Subject: Re: [PATCHv5 6/6] PCI: layerscape: Add power management support
>
> Hi,
>
> [...]
> > +/* PF Message Command Register */
> > +#define LS_PCIE_PF_MCR 0x2c
> > +#define PF_MCR_PTOMR BIT(0)
> > +#define PF_MCR_EXL2S BIT(1)
> > +
> > +/* LS1021A PEXn PM Write Control Register */
> > +#define SCFG_PEXPMWRCR(idx) (0x5c + (idx) * 0x64)
> > +#define PMXMTTURNOFF BIT(31)
> > +#define SCFG_PEXSFTRSTCR 0x190
> > +#define PEXSR(idx) BIT(idx)
> > +
> > +/* LS1043A PEX PME control register */
> > +#define SCFG_PEXPMECR 0x144
> > +#define PEXPME(idx) BIT(31 - (idx) * 4)
> > +
> > +/* LS1043A PEX LUT debug register */
> > +#define LS_PCIE_LDBG 0x7fc
> > +#define LDBG_SR BIT(30)
> > +#define LDBG_WE BIT(31)
>
> A small nitpick: a consistent capitalisation of "control" and "debug", and
> "register" in the comments above.
Good suggestion, will make them consistent next version.
>
> [...]
> > +static void ls_pcie_lut_writel(struct ls_pcie *pcie, u32 off, u32
> > +val) {
> > + if (pcie->big_endian)
> > + return iowrite32be(val, pcie->lut_base + off);
> > +
> > + return iowrite32(val, pcie->lut_base + off);
> > +
> > +}
>
> Surplus newline above after the return statement.
>
> [...]
> > +static void ls_pcie_pf_writel(struct ls_pcie *pcie, u32 off, u32 val)
> > +{
> > + if (pcie->big_endian)
> > + return iowrite32be(val, pcie->pf_base + off);
> > +
> > + return iowrite32(val, pcie->pf_base + off);
> > +
> > +}
>
> Surplus newline above after the return statement.
>
Will remove these lines next version.
> [...]
> > +static void ls_pcie_send_turnoff_msg(struct ls_pcie *pcie) {
> > + u32 val;
> > + int ret;
> > +
> > + val = ls_pcie_pf_readl(pcie, LS_PCIE_PF_MCR);
> > + val |= PF_MCR_PTOMR;
> > + ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val);
> > +
> > + ret = readx_poll_timeout(ls_pcie_pf_readl_addr, LS_PCIE_PF_MCR,
> > + val, !(val & PF_MCR_PTOMR), 100, 10000);
> > + if (ret)
> > + dev_info(pcie->pci->dev, "poll turn off message timeout\n"); }
>
> Would this dev_info() be more of a warning or an error? A timeout is
> potentially a problem, correct?
>
An error message is better here, will change next version.
> [...]
> > +static void ls1021a_pcie_send_turnoff_msg(struct ls_pcie *pcie) {
> > + u32 val;
> > +
> > + if (!pcie->scfg) {
> > + dev_dbg(pcie->pci->dev, "SYSCFG is NULL\n");
> > + return;
> > + }
> > +
> > + /* Send Turn_off message */
> > + regmap_read(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), &val);
> > + val |= PMXMTTURNOFF;
> > + regmap_write(pcie->scfg, SCFG_PEXPMWRCR(pcie->index), val);
> > +
> > + mdelay(10);
>
> We often, customary, document why a particular mdelay() is needed. You also
> did this in other part of the code, so perhaps adding a note here (and
> everywhere else) would be nice for keeping the consistency.
>
Will add next version.
> [...]
> > +static void ls_pcie_exit_from_l2(struct ls_pcie *pcie) {
> > + u32 val;
> > + int ret;
> > +
> > + val = ls_pcie_pf_readl(pcie, LS_PCIE_PF_MCR);
> > + val |= PF_MCR_EXL2S;
> > + ls_pcie_pf_writel(pcie, LS_PCIE_PF_MCR, val);
> > +
> > + ret = readx_poll_timeout(ls_pcie_pf_readl_addr, LS_PCIE_PF_MCR,
> > + val, !(val & PF_MCR_EXL2S), 100, 10000);
> > + if (ret)
> > + dev_info(pcie->pci->dev, "poll exit L2 state timeout\n"); }
>
> Similarly to the question above: is this timeout something more severe and
> would warrant a warning or an error here instead?
>
Agree.
> [...]
> > +static void ls1021a_pcie_exit_from_l2(struct ls_pcie *pcie) {
> > + u32 val;
> > +
> > + regmap_read(pcie->scfg, SCFG_PEXSFTRSTCR, &val);
> > + val |= PEXSR(pcie->index);
> > + regmap_write(pcie->scfg, SCFG_PEXSFTRSTCR, val);
> > +
> > + regmap_read(pcie->scfg, SCFG_PEXSFTRSTCR, &val);
> > + val &= ~PEXSR(pcie->index);
> > + regmap_write(pcie->scfg, SCFG_PEXSFTRSTCR, val);
> > +
> > + mdelay(1);
>
> Aside of documenting this mdelay() here, if possible, would 1 be enough?
> Everywhere else you seem to use 10 consistently.
>
It's enough and didn't encounter a fail in thousands regressions.
> > +
> > + ls_pcie_retrain_link(pcie);
> > +}
> > +static void ls1043a_pcie_exit_from_l2(struct ls_pcie *pcie)
>
> Missing newline above to separate code blocks.
>
Will add next version.
> > +{
> > + u32 val;
> > +
> > + val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
> > + val |= LDBG_WE;
> > + ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
> > +
> > + val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
> > + val |= LDBG_SR;
> > + ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
> > +
> > + val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
> > + val &= ~LDBG_SR;
> > + ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
> > +
> > + val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
> > + val &= ~LDBG_WE;
> > + ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
> > +
> > + mdelay(1);
>
> See comment above.
>
> [...]
> > +static int ls1021a_pcie_pm_init(struct ls_pcie *pcie) {
> > + struct device *dev = pcie->pci->dev;
> > + u32 index[2];
> > + int ret;
> > +
> > + pcie->scfg = syscon_regmap_lookup_by_phandle(dev->of_node,
> > + "fsl,pcie-scfg");
> > + if (IS_ERR(pcie->scfg)) {
> > + ret = PTR_ERR(pcie->scfg);
> > + dev_err(dev, "No syscfg phandle specified\n");
> > + pcie->scfg = NULL;
> > + return ret;
> > + }
> > +
> > + ret = of_property_read_u32_array(dev->of_node, "fsl,pcie-scfg",
> > + index, 2);
> > + if (ret) {
> > + pcie->scfg = NULL;
> > + return ret;
> > + }
> > +
> > + pcie->index = index[1];
> > +
> > + return 0;
> > +}
>
> Just an idea: what about using goto for error handling?
>
> (...)
> if (IS_ERR(pcie->scfg)) {
> ret = PTR_ERR(pcie->scfg);
> dev_err(dev, "No syscfg phandle specified\n");
> goto error;
> }
>
> ret = of_property_read_u32_array(dev->of_node, "fsl,pcie-scfg",
> index, 2);
> if (ret)
> goto error;
>
> pcie->index = index[1];
>
> return 0;
>
> error:
> pcie->scfg = NULL;
> return ret;
> }
>
> Not necessarily better or worse compared with your version, so it would be
> more of a matter of personal preference here.
Thanks for the good suggestion!
>
> > +static int ls_pcie_suspend_noirq(struct device *dev) {
> > + struct ls_pcie *pcie = dev_get_drvdata(dev);
> > + struct dw_pcie *pci = pcie->pci;
> > + u32 val;
> > + int ret;
> > +
> > + if (!ls_pcie_pm_check(pcie))
> > + return 0;
> > +
> > + pcie->drvdata->pm_ops->send_turn_off_message(pcie);
> > +
> > + /* 10ms timeout to check L2 ready */
> > + ret = readl_poll_timeout(pci->dbi_base + PCIE_PORT_DEBUG0,
> > + val, LS_PCIE_IS_L2(val), 100, 10000);
> > + if (ret) {
> > + dev_err(dev, "PCIe link enter L2 timeout! ltssm = 0x%x\n", val);
> > + return ret;
> > + }
>
> The error message above could be improve to be more like an error stating that
> something failed and such, as currently it looks like a debug message, unless it
> was intended as such.
Exactly, will improve.
>
> [...]
> > +static int ls_pcie_resume_noirq(struct device *dev) {
> > + struct ls_pcie *pcie = dev_get_drvdata(dev);
> > + struct dw_pcie *pci = pcie->pci;
> > + int ret;
> > +
> > + if (!ls_pcie_pm_check(pcie))
> > + return 0;
> > +
> > + ls_pcie_set_dstate(pcie, 0x0);
> > +
> > + pcie->drvdata->pm_ops->exit_from_l2(pcie);
> > +
> > + dw_pcie_setup_rc(&pci->pp);
> > +
> > + /* delay 10 ms to access EP */
> > + mdelay(10);
> > +
> > + ret = ls_pcie_host_init(&pci->pp);
> > + if (ret) {
> > + dev_err(dev, "ls_pcie_host_init failed! ret = 0x%x\n", ret);
> > + return ret;
> > + }
>
> A small nitpick: error messages that are directed at end users should have a little
> more context than just the function name.
Will remove the return value check, currently this func always succeed.
Thanks,
Zhiqiang
>
> Krzysztof