[PATCH v2 1/2] phy: samsung: phy-exynos-pcie: sanitize init/power_on callbacks

[Marek Szyprowski <m.szyprowski@samsung.com>]

The exynos-pcie driver called phy_power_on() and then phy_init() for some
historical reasons. However the generic PHY framework assumes that the
proper sequence is to call phy_init() first, then phy_power_on(). The
operations done by both functions should be considered as one action and
as such they are called by the exynos-pcie driver (without doing anything
between them). The initialization is just a sequence of register writes,
which cannot be altered, without breaking the hardware operation.

To match the generic PHY framework requirement, simply call the
power_on() code directly from the init() callback and drop it from the
phy ops.  This way the driver will also work with the old (incorrect) PHY
initialization call sequence.

Reported-by: Bjorn Helgaas <helgaas@kernel.org>
Suggested-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
v2:
- keep exynos5433_pcie_phy_power_on() function and call it directly from
  exynos5433_pcie_phy_init() as suggested by Vinod Koul
---
 drivers/phy/samsung/phy-exynos-pcie.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/phy/samsung/phy-exynos-pcie.c b/drivers/phy/samsung/phy-exynos-pcie.c
index 578cfe07d07a..152f99762093 100644
--- a/drivers/phy/samsung/phy-exynos-pcie.c
+++ b/drivers/phy/samsung/phy-exynos-pcie.c
@@ -47,10 +47,15 @@ static void exynos_pcie_phy_writel(void __iomem *base, u32 val, u32 offset)
 }
 
 /* Exynos5433 specific functions */
+static int exynos5433_pcie_phy_power_on(struct phy *phy);
+
 static int exynos5433_pcie_phy_init(struct phy *phy)
 {
 	struct exynos_pcie_phy *ep = phy_get_drvdata(phy);
 
+	/* Power must be enabled in PMU before any other register write */
+	exynos5433_pcie_phy_power_on(phy);
+
 	regmap_update_bits(ep->fsysreg,	PCIE_EXYNOS5433_PHY_COMMON_RESET,
 			   PCIE_PHY_RESET, 1);
 	regmap_update_bits(ep->fsysreg, PCIE_EXYNOS5433_PHY_MAC_RESET,
@@ -135,7 +140,6 @@ static int exynos5433_pcie_phy_power_off(struct phy *phy)
 
 static const struct phy_ops exynos5433_phy_ops = {
 	.init		= exynos5433_pcie_phy_init,
-	.power_on	= exynos5433_pcie_phy_power_on,
 	.power_off	= exynos5433_pcie_phy_power_off,
 	.owner		= THIS_MODULE,
 };
-- 
2.17.1