PCI: exynos: Support the PHY generic framework

Switch the pci-exynos driver to generic PHY framework.  At the same time
backward compatibility is preserved: Warning will be printed for old DTB.

Refer to the binding file:
- Documentation/devicetree/bindings/pci/samsung,exynos5440-pcie.txt

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Jingoo Han <jingoohan1@gmail.com>

1 files changed, 50 insertions, 4 deletions

diff --git a/drivers/pci/host/pci-exynos.c b/drivers/pci/host/pci-exynos.c
index ab9e67465b9b..c86961feaa6f 100644
--- a/drivers/pci/host/pci-exynos.c
+++ b/drivers/pci/host/pci-exynos.c
@@ -21,6 +21,7 @@
 #include <linux/of_gpio.h>
 #include <linux/pci.h>
 #include <linux/platform_device.h>
+#include <linux/phy/phy.h>
 #include <linux/resource.h>
 #include <linux/signal.h>
 #include <linux/types.h>
@@ -110,6 +111,10 @@ struct exynos_pcie {
         struct exynos_pcie_clk_res      *clk_res;
         const struct exynos_pcie_ops    *ops;
         int                             reset_gpio;
+
+        /* For Generic PHY Framework */
+        bool                            using_phy;
+        struct phy                      *phy;
 };
 
 struct exynos_pcie_ops {
@@ -126,6 +131,10 @@ static int exynos5440_pcie_get_mem_resources(struct platform_device *pdev,
         struct resource *res;
         struct device *dev = ep->pp.dev;
 
+        /* If using the PHY framework, doesn't need to get other resource */
+        if (ep->using_phy)
+                return 0;
+
         ep->mem_res = devm_kzalloc(dev, sizeof(*ep->mem_res), GFP_KERNEL);
         if (!ep->mem_res)
                 return -ENOMEM;
@@ -396,10 +405,28 @@ static int exynos_pcie_establish_link(struct exynos_pcie *ep)
         }
 
         exynos_pcie_assert_core_reset(ep);
-        exynos_pcie_assert_phy_reset(ep);
-        exynos_pcie_deassert_phy_reset(ep);
-        exynos_pcie_power_on_phy(ep);
-        exynos_pcie_init_phy(ep);
+
+        if (ep->using_phy) {
+                phy_reset(ep->phy);
+
+                exynos_pcie_writel(ep->mem_res->elbi_base, 1,
+                                PCIE_PWR_RESET);
+
+                phy_power_on(ep->phy);
+                phy_init(ep->phy);
+        } else {
+                exynos_pcie_assert_phy_reset(ep);
+                exynos_pcie_deassert_phy_reset(ep);
+                exynos_pcie_power_on_phy(ep);
+                exynos_pcie_init_phy(ep);
+
+                /* pulse for common reset */
+                exynos_pcie_writel(ep->mem_res->block_base, 1,
+                                        PCIE_PHY_COMMON_RESET);
+                udelay(500);
+                exynos_pcie_writel(ep->mem_res->block_base, 0,
+                                        PCIE_PHY_COMMON_RESET);
+        }
 
         /* pulse for common reset */
         exynos_pcie_writel(ep->mem_res->block_base, 1, PCIE_PHY_COMMON_RESET);
@@ -418,6 +445,11 @@ static int exynos_pcie_establish_link(struct exynos_pcie *ep)
         if (!dw_pcie_wait_for_link(pp))
                 return 0;
 
+        if (ep->using_phy) {
+                phy_power_off(ep->phy);
+                return -ETIMEDOUT;
+        }
+
         while (exynos_pcie_readl(ep->mem_res->phy_base,
                                 PCIE_PHY_PLL_LOCKED) == 0) {
                 val = exynos_pcie_readl(ep->mem_res->block_base,
@@ -624,6 +656,17 @@ static int __init exynos_pcie_probe(struct platform_device *pdev)
 
         ep->reset_gpio = of_get_named_gpio(np, "reset-gpio", 0);
 
+        /* Assume that controller doesn't use the PHY framework */
+        ep->using_phy = false;
+
+        ep->phy = devm_of_phy_get(dev, np, NULL);
+        if (IS_ERR(ep->phy)) {
+                if (PTR_ERR(ep->phy) == -EPROBE_DEFER)
+                        return PTR_ERR(ep->phy);
+                dev_warn(dev, "Use the 'phy' property. Current DT of pci-exynos was deprecated!!\n");
+        } else
+                ep->using_phy = true;
+
         if (ep->ops && ep->ops->get_mem_resources) {
                 ret = ep->ops->get_mem_resources(pdev, ep);
                 if (ret)
@@ -647,6 +690,9 @@ static int __init exynos_pcie_probe(struct platform_device *pdev)
         return 0;
 
 fail_probe:
+        if (ep->using_phy)
+                phy_exit(ep->phy);
+
         if (ep->ops && ep->ops->deinit_clk_resources)
                 ep->ops->deinit_clk_resources(ep);
         return ret;