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Subject[PATCH v3 2/2] phy: stm32: register usbphyc as clock provider of ck_usbo_48m clock
Date
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: Amelie Delaunay <amelie.delaunay@foss.st.com>
---
Changes in v2:
- fix COMMON_CLK dependency issue reported by kernel test robot
---
drivers/phy/st/Kconfig | 1 +
drivers/phy/st/phy-stm32-usbphyc.c | 65 ++++++++++++++++++++++++++++++
2 files changed, 66 insertions(+)

diff --git a/drivers/phy/st/Kconfig b/drivers/phy/st/Kconfig
index b32f44ff9033..3fc3d0781fb8 100644
--- a/drivers/phy/st/Kconfig
+++ b/drivers/phy/st/Kconfig
@@ -36,6 +36,7 @@ config PHY_STIH407_USB
config PHY_STM32_USBPHYC
tristate "STMicroelectronics STM32 USB HS PHY Controller driver"
depends on ARCH_STM32 || COMPILE_TEST
+ depends on COMMON_CLK
select GENERIC_PHY
help
Enable this to support the High-Speed USB transceivers that are part
diff --git a/drivers/phy/st/phy-stm32-usbphyc.c b/drivers/phy/st/phy-stm32-usbphyc.c
index d08fbb180e43..c184f4e34584 100644
--- a/drivers/phy/st/phy-stm32-usbphyc.c
+++ b/drivers/phy/st/phy-stm32-usbphyc.c
@@ -7,6 +7,7 @@
*/
#include <linux/bitfield.h>
#include <linux/clk.h>
+#include <linux/clk-provider.h>
#include <linux/delay.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
@@ -70,6 +71,7 @@ struct stm32_usbphyc {
struct regulator *vdda1v1;
struct regulator *vdda1v8;
atomic_t n_pll_cons;
+ struct clk_hw clk48_hw;
int switch_setup;
};

@@ -295,6 +297,61 @@ static const struct phy_ops stm32_usbphyc_phy_ops = {
.owner = THIS_MODULE,
};

+static int stm32_usbphyc_clk48_prepare(struct clk_hw *hw)
+{
+ struct stm32_usbphyc *usbphyc = container_of(hw, struct stm32_usbphyc, clk48_hw);
+
+ return stm32_usbphyc_pll_enable(usbphyc);
+}
+
+static void stm32_usbphyc_clk48_unprepare(struct clk_hw *hw)
+{
+ struct stm32_usbphyc *usbphyc = container_of(hw, struct stm32_usbphyc, clk48_hw);
+
+ stm32_usbphyc_pll_disable(usbphyc);
+}
+
+static unsigned long stm32_usbphyc_clk48_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
+{
+ return 48000000;
+}
+
+static const struct clk_ops usbphyc_clk48_ops = {
+ .prepare = stm32_usbphyc_clk48_prepare,
+ .unprepare = stm32_usbphyc_clk48_unprepare,
+ .recalc_rate = stm32_usbphyc_clk48_recalc_rate,
+};
+
+static void stm32_usbphyc_clk48_unregister(void *data)
+{
+ struct stm32_usbphyc *usbphyc = data;
+
+ of_clk_del_provider(usbphyc->dev->of_node);
+ clk_hw_unregister(&usbphyc->clk48_hw);
+}
+
+static int stm32_usbphyc_clk48_register(struct stm32_usbphyc *usbphyc)
+{
+ struct device_node *node = usbphyc->dev->of_node;
+ struct clk_init_data init = { };
+ int ret = 0;
+
+ init.name = "ck_usbo_48m";
+ init.ops = &usbphyc_clk48_ops;
+
+ usbphyc->clk48_hw.init = &init;
+
+ ret = clk_hw_register(usbphyc->dev, &usbphyc->clk48_hw);
+ if (ret)
+ return ret;
+
+ ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, &usbphyc->clk48_hw);
+ if (ret)
+ clk_hw_unregister(&usbphyc->clk48_hw);
+
+ return ret;
+}
+
static void stm32_usbphyc_switch_setup(struct stm32_usbphyc *usbphyc,
u32 utmi_switch)
{
@@ -473,6 +530,12 @@ static int stm32_usbphyc_probe(struct platform_device *pdev)
goto clk_disable;
}

+ ret = stm32_usbphyc_clk48_register(usbphyc);
+ if (ret) {
+ dev_err(dev, "failed to register ck_usbo_48m clock: %d\n", ret);
+ goto clk_disable;
+ }
+
version = readl_relaxed(usbphyc->base + STM32_USBPHYC_VERSION);
dev_info(dev, "registered rev:%lu.%lu\n",
FIELD_GET(MAJREV, version), FIELD_GET(MINREV, version));
@@ -497,6 +560,8 @@ static int stm32_usbphyc_remove(struct platform_device *pdev)
if (usbphyc->phys[port]->active)
stm32_usbphyc_phy_exit(usbphyc->phys[port]->phy);

+ stm32_usbphyc_clk48_unregister(usbphyc);
+
clk_disable_unprepare(usbphyc->clk);

return 0;
--
2.17.1
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