From 9406f9735c998a179d8ecc886ad7d5287473222f Mon Sep 17 00:00:00 2001
From: Patrick Delaunay <patrick.delaunay@foss.st.com>
Date: Tue, 26 Apr 2022 14:37:48 +0200
Subject: [PATCH] phy: stm32-usbphyc: usbphyc is a clock provider of
 ck_usbo_48m clock

ck_usbo_48m is generated by usbphyc PLL and used by OTG controller
for Full-Speed use cases with dedicated Full-Speed transceiver.

ck_usbo_48m is available as soon as the PLL is enabled.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
---
 drivers/phy/phy-stm32-usbphyc.c | 79 +++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)

diff --git a/drivers/phy/phy-stm32-usbphyc.c b/drivers/phy/phy-stm32-usbphyc.c
index bb743fe16f..9f0b7d7118 100644
--- a/drivers/phy/phy-stm32-usbphyc.c
+++ b/drivers/phy/phy-stm32-usbphyc.c
@@ -7,6 +7,7 @@
 
 #include <common.h>
 #include <clk.h>
+#include <clk-uclass.h>
 #include <div64.h>
 #include <dm.h>
 #include <fdtdec.h>
@@ -17,6 +18,7 @@
 #include <usb.h>
 #include <asm/io.h>
 #include <dm/device_compat.h>
+#include <dm/lists.h>
 #include <dm/of_access.h>
 #include <linux/bitfield.h>
 #include <linux/bitops.h>
@@ -72,6 +74,9 @@
 #define PLL_INFF_MIN_RATE	19200000 /* in Hz */
 #define PLL_INFF_MAX_RATE	38400000 /* in Hz */
 
+/* USBPHYC_CLK48 */
+#define USBPHYC_CLK48_FREQ	48000000 /* in Hz */
+
 enum boosting_vals {
 	BOOST_1000_UA = 1000,
 	BOOST_2000_UA = 2000,
@@ -518,6 +523,16 @@ static const struct phy_ops stm32_usbphyc_phy_ops = {
 	.of_xlate = stm32_usbphyc_of_xlate,
 };
 
+static int stm32_usbphyc_bind(struct udevice *dev)
+{
+	int ret;
+
+	ret = device_bind_driver_to_node(dev, "stm32-usbphyc-clk", "ck_usbo_48m",
+					 dev_ofnode(dev), NULL);
+
+	return log_ret(ret);
+}
+
 static int stm32_usbphyc_probe(struct udevice *dev)
 {
 	struct stm32_usbphyc *usbphyc = dev_get_priv(dev);
@@ -611,6 +626,70 @@ U_BOOT_DRIVER(stm32_usb_phyc) = {
 	.id = UCLASS_PHY,
 	.of_match = stm32_usbphyc_of_match,
 	.ops = &stm32_usbphyc_phy_ops,
+	.bind = stm32_usbphyc_bind,
 	.probe = stm32_usbphyc_probe,
 	.priv_auto	= sizeof(struct stm32_usbphyc),
 };
+
+struct stm32_usbphyc_clk {
+	bool enable;
+};
+
+static ulong stm32_usbphyc_clk48_get_rate(struct clk *clk)
+{
+	return USBPHYC_CLK48_FREQ;
+}
+
+static int stm32_usbphyc_clk48_enable(struct clk *clk)
+{
+	struct stm32_usbphyc_clk *usbphyc_clk = dev_get_priv(clk->dev);
+	struct stm32_usbphyc *usbphyc;
+	int ret;
+
+	if (usbphyc_clk->enable)
+		return 0;
+
+	usbphyc = dev_get_priv(clk->dev->parent);
+
+	/* ck_usbo_48m is generated by usbphyc PLL */
+	ret = stm32_usbphyc_pll_enable(usbphyc);
+	if (ret)
+		return ret;
+
+	usbphyc_clk->enable = true;
+
+	return 0;
+}
+
+static int stm32_usbphyc_clk48_disable(struct clk *clk)
+{
+	struct stm32_usbphyc_clk *usbphyc_clk = dev_get_priv(clk->dev);
+	struct stm32_usbphyc *usbphyc;
+	int ret;
+
+	if (!usbphyc_clk->enable)
+		return 0;
+
+	usbphyc = dev_get_priv(clk->dev->parent);
+
+	ret = stm32_usbphyc_pll_disable(usbphyc);
+	if (ret)
+		return ret;
+
+	usbphyc_clk->enable = false;
+
+	return 0;
+}
+
+const struct clk_ops usbphyc_clk48_ops = {
+	.get_rate = stm32_usbphyc_clk48_get_rate,
+	.enable = stm32_usbphyc_clk48_enable,
+	.disable = stm32_usbphyc_clk48_disable,
+};
+
+U_BOOT_DRIVER(stm32_usb_phyc_clk) = {
+	.name = "stm32-usbphyc-clk",
+	.id = UCLASS_CLK,
+	.ops = &usbphyc_clk48_ops,
+	.priv_auto = sizeof(struct stm32_usbphyc_clk),
+};
-- 
2.39.5