[RFC PATCH v4 3/7] phy: rockcip-pcie: reconstruct driver to support per-lane PHYs

[Shawn Lin <shawn.lin@rock-chips.com>]

This patch reconstructs the whole driver to support per-lane
PHYs. Note that we could also support the legacy PHY if you
don't provide argument to our of_xlate.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Tested-by: Jeffy Chen <jeffy.chen@rock-chips.com>
---

Changes in v4: None
Changes in v3:
- remove unnecessary forward declaration
- keep mutex inside struct rockchip_pcie_phy
- fix wrong check of args number
- move de-idle lanes after deasserting the reset

Changes in v2:
- deprecate legacy PHY model
- improve rockchip_pcie_phy_of_xlate
- fix wrong calculation of pwr_cnt and add new init_cnt
- add internal locking
- introduce per-lane data to simply the code

 drivers/phy/rockchip/phy-rockchip-pcie.c | 124 +++++++++++++++++++++++++++----
 1 file changed, 110 insertions(+), 14 deletions(-)

diff --git a/drivers/phy/rockchip/phy-rockchip-pcie.c b/drivers/phy/rockchip/phy-rockchip-pcie.c
index 6904633..b5005a5 100644
--- a/drivers/phy/rockchip/phy-rockchip-pcie.c
+++ b/drivers/phy/rockchip/phy-rockchip-pcie.c
@@ -73,10 +73,39 @@ struct rockchip_pcie_data {
 struct rockchip_pcie_phy {
 	struct rockchip_pcie_data *phy_data;
 	struct regmap *reg_base;
+	struct phy_pcie_instance {
+		struct phy *phy;
+		u32 index;
+	} phys[PHY_MAX_LANE_NUM];
+	struct mutex pcie_mutex;
 	struct reset_control *phy_rst;
 	struct clk *clk_pciephy_ref;
+	int pwr_cnt;
+	int init_cnt;
 };
 
+static inline
+struct rockchip_pcie_phy *to_pcie_phy(struct phy_pcie_instance *inst)
+{
+	return container_of(inst, struct rockchip_pcie_phy,
+					phys[inst->index]);
+}
+
+static struct phy *rockchip_pcie_phy_of_xlate(struct device *dev,
+					      struct of_phandle_args *args)
+{
+	struct rockchip_pcie_phy *rk_phy = dev_get_drvdata(dev);
+
+	if (args->args_count == 0)
+		return rk_phy->phys[0].phy;
+
+	if (WARN_ON(args->args[0] >= PHY_MAX_LANE_NUM))
+		return ERR_PTR(-ENODEV);
+
+	return rk_phy->phys[args->args[0]].phy;
+}
+
+
 static inline void phy_wr_cfg(struct rockchip_pcie_phy *rk_phy,
 			      u32 addr, u32 data)
 {
@@ -116,29 +145,59 @@ static inline u32 phy_rd_cfg(struct rockchip_pcie_phy *rk_phy,
 
 static int rockchip_pcie_phy_power_off(struct phy *phy)
 {
-	struct rockchip_pcie_phy *rk_phy = phy_get_drvdata(phy);
+	struct phy_pcie_instance *inst = phy_get_drvdata(phy);
+	struct rockchip_pcie_phy *rk_phy = to_pcie_phy(inst);
 	int err = 0;
 
+	mutex_lock(&rk_phy->pcie_mutex);
+
+	regmap_write(rk_phy->reg_base,
+		     rk_phy->phy_data->pcie_laneoff,
+		     HIWORD_UPDATE(PHY_LANE_IDLE_OFF,
+				   PHY_LANE_IDLE_MASK,
+				   PHY_LANE_IDLE_A_SHIFT + inst->index));
+
+	if (--rk_phy->pwr_cnt)
+		goto err_out;
+
 	err = reset_control_assert(rk_phy->phy_rst);
 	if (err) {
 		dev_err(&phy->dev, "assert phy_rst err %d\n", err);
-		return err;
+		goto err_restore;
 	}
 
+err_out:
+	mutex_unlock(&rk_phy->pcie_mutex);
 	return 0;
+
+err_restore:
+	++rk_phy->pwr_cnt;
+	regmap_write(rk_phy->reg_base,
+		     rk_phy->phy_data->pcie_laneoff,
+		     HIWORD_UPDATE(!PHY_LANE_IDLE_OFF,
+				   PHY_LANE_IDLE_MASK,
+				   PHY_LANE_IDLE_A_SHIFT + inst->index));
+	mutex_unlock(&rk_phy->pcie_mutex);
+	return err;
 }
 
 static int rockchip_pcie_phy_power_on(struct phy *phy)
 {
-	struct rockchip_pcie_phy *rk_phy = phy_get_drvdata(phy);
+	struct phy_pcie_instance *inst = phy_get_drvdata(phy);
+	struct rockchip_pcie_phy *rk_phy = to_pcie_phy(inst);
 	int err = 0;
 	u32 status;
 	unsigned long timeout;
 
+	mutex_lock(&rk_phy->pcie_mutex);
+
+	if (rk_phy->pwr_cnt++)
+		goto err_out;
+
 	err = reset_control_deassert(rk_phy->phy_rst);
 	if (err) {
 		dev_err(&phy->dev, "deassert phy_rst err %d\n", err);
-		return err;
+		goto err_pwr_cnt;
 	}
 
 	regmap_write(rk_phy->reg_base, rk_phy->phy_data->pcie_conf,
@@ -146,6 +205,12 @@ static int rockchip_pcie_phy_power_on(struct phy *phy)
 				   PHY_CFG_ADDR_MASK,
 				   PHY_CFG_ADDR_SHIFT));
 
+	regmap_write(rk_phy->reg_base,
+		     rk_phy->phy_data->pcie_laneoff,
+		     HIWORD_UPDATE(!PHY_LANE_IDLE_OFF,
+				   PHY_LANE_IDLE_MASK,
+				   PHY_LANE_IDLE_A_SHIFT + inst->index));
+
 	/*
 	 * No documented timeout value for phy operation below,
 	 * so we make it large enough here. And we use loop-break
@@ -214,18 +279,29 @@ static int rockchip_pcie_phy_power_on(struct phy *phy)
 		goto err_pll_lock;
 	}
 
+err_out:
+	mutex_unlock(&rk_phy->pcie_mutex);
 	return 0;
 
 err_pll_lock:
 	reset_control_assert(rk_phy->phy_rst);
+err_pwr_cnt:
+	--rk_phy->pwr_cnt;
+	mutex_unlock(&rk_phy->pcie_mutex);
 	return err;
 }
 
 static int rockchip_pcie_phy_init(struct phy *phy)
 {
-	struct rockchip_pcie_phy *rk_phy = phy_get_drvdata(phy);
+	struct phy_pcie_instance *inst = phy_get_drvdata(phy);
+	struct rockchip_pcie_phy *rk_phy = to_pcie_phy(inst);
 	int err = 0;
 
+	mutex_lock(&rk_phy->pcie_mutex);
+
+	if (rk_phy->init_cnt++)
+		goto err_out;
+
 	err = clk_prepare_enable(rk_phy->clk_pciephy_ref);
 	if (err) {
 		dev_err(&phy->dev, "Fail to enable pcie ref clock.\n");
@@ -238,20 +314,33 @@ static int rockchip_pcie_phy_init(struct phy *phy)
 		goto err_reset;
 	}
 
-	return err;
+err_out:
+	mutex_unlock(&rk_phy->pcie_mutex);
+	return 0;
 
 err_reset:
+
 	clk_disable_unprepare(rk_phy->clk_pciephy_ref);
 err_refclk:
+	--rk_phy->init_cnt;
+	mutex_unlock(&rk_phy->pcie_mutex);
 	return err;
 }
 
 static int rockchip_pcie_phy_exit(struct phy *phy)
 {
-	struct rockchip_pcie_phy *rk_phy = phy_get_drvdata(phy);
+	struct phy_pcie_instance *inst = phy_get_drvdata(phy);
+	struct rockchip_pcie_phy *rk_phy = to_pcie_phy(inst);
+
+	mutex_lock(&rk_phy->pcie_mutex);
+
+	if (--rk_phy->init_cnt)
+		goto err_init_cnt;
 
 	clk_disable_unprepare(rk_phy->clk_pciephy_ref);
 
+err_init_cnt:
+	mutex_unlock(&rk_phy->pcie_mutex);
 	return 0;
 }
 
@@ -283,10 +372,10 @@ static int rockchip_pcie_phy_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct rockchip_pcie_phy *rk_phy;
-	struct phy *generic_phy;
 	struct phy_provider *phy_provider;
 	struct regmap *grf;
 	const struct of_device_id *of_id;
+	int i;
 
 	grf = syscon_node_to_regmap(dev->parent->of_node);
 	if (IS_ERR(grf)) {
@@ -305,6 +394,8 @@ static int rockchip_pcie_phy_probe(struct platform_device *pdev)
 	rk_phy->phy_data = (struct rockchip_pcie_data *)of_id->data;
 	rk_phy->reg_base = grf;
 
+	mutex_init(&rk_phy->pcie_mutex);
+
 	rk_phy->phy_rst = devm_reset_control_get(dev, "phy");
 	if (IS_ERR(rk_phy->phy_rst)) {
 		if (PTR_ERR(rk_phy->phy_rst) != -EPROBE_DEFER)
@@ -319,14 +410,19 @@ static int rockchip_pcie_phy_probe(struct platform_device *pdev)
 		return PTR_ERR(rk_phy->clk_pciephy_ref);
 	}
 
-	generic_phy = devm_phy_create(dev, dev->of_node, &ops);
-	if (IS_ERR(generic_phy)) {
-		dev_err(dev, "failed to create PHY\n");
-		return PTR_ERR(generic_phy);
+	for (i = 0; i < PHY_MAX_LANE_NUM; i++) {
+		rk_phy->phys[i].phy = devm_phy_create(dev, dev->of_node, &ops);
+		if (IS_ERR(rk_phy->phys[i].phy)) {
+			dev_err(dev, "failed to create PHY%d\n", i);
+			return PTR_ERR(rk_phy->phys[i].phy);
+		}
+		rk_phy->phys[i].index = i;
+		phy_set_drvdata(rk_phy->phys[i].phy, &rk_phy->phys[i]);
 	}
 
-	phy_set_drvdata(generic_phy, rk_phy);
-	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+	platform_set_drvdata(pdev, rk_phy);
+	phy_provider = devm_of_phy_provider_register(dev,
+					rockchip_pcie_phy_of_xlate);
 
 	return PTR_ERR_OR_ZERO(phy_provider);
 }
-- 
1.9.1