[PATCH v4 3/3] phy: ti: j721e-wiz: Manage typec-gpio-dir

[Roger Quadros <rogerq@ti.com>]

Based on this GPIO state we need to configure LN10
bit to swap lane0 and lane1 if required (flipped connector).

Type-C companions typically need some time after the cable is
plugged before and before they reflect the correct status of
Type-C plug orientation on the DIR line.

Type-C Spec specifies CC attachment debounce time (tCCDebounce)
of 100 ms (min) to 200 ms (max).

Use the DT property to figure out if we need to add delay
or not before sampling the Type-C DIR line.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Reviewed-by: Jyri Sarha <jsarha@ti.com>
---
 drivers/phy/ti/phy-j721e-wiz.c | 61 ++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/drivers/phy/ti/phy-j721e-wiz.c b/drivers/phy/ti/phy-j721e-wiz.c
index 2a95da843e9f..9ab35c894f05 100644
--- a/drivers/phy/ti/phy-j721e-wiz.c
+++ b/drivers/phy/ti/phy-j721e-wiz.c
@@ -9,6 +9,8 @@
 #include <dt-bindings/phy/phy.h>
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/mux/consumer.h>
@@ -22,6 +24,7 @@
 #define WIZ_SERDES_CTRL		0x404
 #define WIZ_SERDES_TOP_CTRL	0x408
 #define WIZ_SERDES_RST		0x40c
+#define WIZ_SERDES_TYPEC	0x410
 #define WIZ_LANECTL(n)		(0x480 + (0x40 * (n)))
 
 #define WIZ_MAX_LANES		4
@@ -29,6 +32,8 @@
 #define WIZ_DIV_NUM_CLOCKS_16G	2
 #define WIZ_DIV_NUM_CLOCKS_10G	1
 
+#define WIZ_SERDES_TYPEC_LN10_SWAP	BIT(30)
+
 enum wiz_lane_standard_mode {
 	LANE_MODE_GEN1,
 	LANE_MODE_GEN2,
@@ -94,6 +99,9 @@ static const struct reg_field p_standard_mode[WIZ_MAX_LANES] = {
 	REG_FIELD(WIZ_LANECTL(3), 24, 25),
 };
 
+static const struct reg_field typec_ln10_swap =
+					REG_FIELD(WIZ_SERDES_TYPEC, 30, 30);
+
 struct wiz_clk_mux {
 	struct clk_hw		hw;
 	struct regmap_field	*field;
@@ -185,6 +193,9 @@ enum wiz_type {
 	J721E_WIZ_10G,
 };
 
+#define WIZ_TYPEC_DIR_DEBOUNCE_MIN	100	/* ms */
+#define WIZ_TYPEC_DIR_DEBOUNCE_MAX	1000
+
 struct wiz {
 	struct regmap		*regmap;
 	enum wiz_type		type;
@@ -201,11 +212,14 @@ struct wiz {
 	struct regmap_field	*pma_cmn_refclk_mode;
 	struct regmap_field	*pma_cmn_refclk_dig_div;
 	struct regmap_field	*pma_cmn_refclk1_dig_div;
+	struct regmap_field	*typec_ln10_swap;
 
 	struct device		*dev;
 	u32			num_lanes;
 	struct platform_device	*serdes_pdev;
 	struct reset_controller_dev wiz_phy_reset_dev;
+	struct gpio_desc	*gpio_typec_dir;
+	int			typec_dir_delay;
 };
 
 static int wiz_reset(struct wiz *wiz)
@@ -404,6 +418,13 @@ static int wiz_regfield_init(struct wiz *wiz)
 		}
 	}
 
+	wiz->typec_ln10_swap = devm_regmap_field_alloc(dev, regmap,
+						       typec_ln10_swap);
+	if (IS_ERR(wiz->typec_ln10_swap)) {
+		dev_err(dev, "LN10_SWAP reg field init failed\n");
+		return PTR_ERR(wiz->typec_ln10_swap);
+	}
+
 	return 0;
 }
 
@@ -703,6 +724,17 @@ static int wiz_phy_reset_deassert(struct reset_controller_dev *rcdev,
 	struct wiz *wiz = dev_get_drvdata(dev);
 	int ret;
 
+	/* if typec-dir gpio was specified, set LN10 SWAP bit based on that */
+	if (id == 0 && wiz->gpio_typec_dir) {
+		if (wiz->typec_dir_delay)
+			msleep_interruptible(wiz->typec_dir_delay);
+
+		if (gpiod_get_value_cansleep(wiz->gpio_typec_dir))
+			regmap_field_write(wiz->typec_ln10_swap, 1);
+		else
+			regmap_field_write(wiz->typec_ln10_swap, 0);
+	}
+
 	if (id == 0) {
 		ret = regmap_field_write(wiz->phy_reset_n, true);
 		return ret;
@@ -789,6 +821,35 @@ static int wiz_probe(struct platform_device *pdev)
 		goto err_addr_to_resource;
 	}
 
+	wiz->gpio_typec_dir = devm_gpiod_get_optional(dev, "typec-dir",
+						      GPIOD_IN);
+	if (IS_ERR(wiz->gpio_typec_dir)) {
+		ret = PTR_ERR(wiz->gpio_typec_dir);
+		if (ret != -EPROBE_DEFER)
+			dev_err(dev, "Failed to request typec-dir gpio: %d\n",
+				ret);
+		goto err_addr_to_resource;
+	}
+
+	if (wiz->gpio_typec_dir) {
+		ret = of_property_read_u32(node, "typec-dir-debounce-ms",
+					   &wiz->typec_dir_delay);
+		if (ret && ret != -EINVAL) {
+			dev_err(dev, "Invalid typec-dir-debounce property\n");
+			goto err_addr_to_resource;
+		}
+
+		/* use min. debounce from Type-C spec if not provided in DT  */
+		if (ret == -EINVAL)
+			wiz->typec_dir_delay = WIZ_TYPEC_DIR_DEBOUNCE_MIN;
+
+		if (wiz->typec_dir_delay < WIZ_TYPEC_DIR_DEBOUNCE_MIN ||
+		    wiz->typec_dir_delay > WIZ_TYPEC_DIR_DEBOUNCE_MAX) {
+			dev_err(dev, "Invalid typec-dir-debounce property\n");
+			goto err_addr_to_resource;
+		}
+	}
+
 	wiz->dev = dev;
 	wiz->regmap = regmap;
 	wiz->num_lanes = num_lanes;
-- 
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