[PATCH v5 1/4] PCI: layerscape: Add function pointer for exit_from_l2()

[Frank Li]

Since difference SoCs require different sequence for exiting L2, let's add
a separate "exit_from_l2()" callback. This callback can be used to execute
SoC specific sequence.

Change ls_pcie_exit_from_l2() return value from void to int. Return error
if exit_from_l2() failure at exit resume flow.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasi...@linaro.org>
Signed-off-by: Frank Li <frank...@nxp.com>
---

Notes:
    Change from v4 to v5
    - none
    Change from v3 to v4
    - update commit message
      Add mani's review by tag
    Change from v2 to v3
    - fixed according to mani's feedback
      1. update commit message
      2. move dw_pcie_host_ops to next patch
      3. check return value from exit_from_l2()
    Change from v1 to v2
    - change subject 'a' to 'A'
    
    Change from v1 to v2
    - change subject 'a' to 'A'

 drivers/pci/controller/dwc/pci-layerscape.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-layerscape.c 
b/drivers/pci/controller/dwc/pci-layerscape.c
index 37956e09c65bd..aea89926bcc4f 100644
--- a/drivers/pci/controller/dwc/pci-layerscape.c
+++ b/drivers/pci/controller/dwc/pci-layerscape.c
@@ -39,6 +39,7 @@
 
 struct ls_pcie_drvdata {
        const u32 pf_off;
+       int (*exit_from_l2)(struct dw_pcie_rp *pp);
        bool pm_support;
 };
 
@@ -125,7 +126,7 @@ static void ls_pcie_send_turnoff_msg(struct dw_pcie_rp *pp)
                dev_err(pcie->pci->dev, "PME_Turn_off timeout\n");
 }
 
-static void ls_pcie_exit_from_l2(struct dw_pcie_rp *pp)
+static int ls_pcie_exit_from_l2(struct dw_pcie_rp *pp)
 {
        struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
        struct ls_pcie *pcie = to_ls_pcie(pci);
@@ -150,6 +151,8 @@ static void ls_pcie_exit_from_l2(struct dw_pcie_rp *pp)
                                 10000);
        if (ret)
                dev_err(pcie->pci->dev, "L2 exit timeout\n");
+
+       return ret;
 }
 
 static int ls_pcie_host_init(struct dw_pcie_rp *pp)
@@ -180,6 +183,7 @@ static const struct ls_pcie_drvdata ls1021a_drvdata = {
 static const struct ls_pcie_drvdata layerscape_drvdata = {
        .pf_off = 0xc0000,
        .pm_support = true,
+       .exit_from_l2 = ls_pcie_exit_from_l2,
 };
 
 static const struct of_device_id ls_pcie_of_match[] = {
@@ -247,11 +251,14 @@ static int ls_pcie_suspend_noirq(struct device *dev)
 static int ls_pcie_resume_noirq(struct device *dev)
 {
        struct ls_pcie *pcie = dev_get_drvdata(dev);
+       int ret;
 
        if (!pcie->drvdata->pm_support)
                return 0;
 
-       ls_pcie_exit_from_l2(&pcie->pci->pp);
+       ret = pcie->drvdata->exit_from_l2(&pcie->pci->pp);
+       if (ret)
+               return ret;
 
        return dw_pcie_resume_noirq(pcie->pci);
 }
-- 
2.34.1