[PATCH v4 11/14] clk: stm32mp13: add safe mux management
From: <hidden>
Date: 2022-05-16 07:08:33
Also in:
linux-clk, linux-devicetree, lkml
Subsystem:
common clk framework, the rest · Maintainers:
Michael Turquette, Stephen Boyd, Linus Torvalds
From: Gabriel Fernandez <redacted> Some muxes need to set a the safe position when clock is off. Signed-off-by: Gabriel Fernandez <redacted> --- drivers/clk/stm32/clk-stm32-core.c | 54 ++++++++++++++++++++++++++++++ drivers/clk/stm32/clk-stm32-core.h | 1 + drivers/clk/stm32/clk-stm32mp13.c | 11 +++--- 3 files changed, 62 insertions(+), 4 deletions(-)
diff --git a/drivers/clk/stm32/clk-stm32-core.c b/drivers/clk/stm32/clk-stm32-core.c
index e5a22bb09495..45a279e73779 100644
--- a/drivers/clk/stm32/clk-stm32-core.c
+++ b/drivers/clk/stm32/clk-stm32-core.c@@ -495,6 +495,54 @@ static int clk_stm32_composite_is_enabled(struct clk_hw *hw) return stm32_gate_is_enabled(composite->base, composite->clock_data, composite->gate_id); } +#define MUX_SAFE_POSITION 0 + +static int clk_stm32_has_safe_mux(struct clk_hw *hw) +{ + struct clk_stm32_composite *composite = to_clk_stm32_composite(hw); + const struct stm32_mux_cfg *mux = &composite->clock_data->muxes[composite->mux_id]; + + return !!(mux->flags & MUX_SAFE); +} + +static void clk_stm32_set_safe_position_mux(struct clk_hw *hw) +{ + struct clk_stm32_composite *composite = to_clk_stm32_composite(hw); + + if (!clk_stm32_composite_is_enabled(hw)) { + unsigned long flags = 0; + + if (composite->clock_data->is_multi_mux) { + struct clk_hw *other_mux_hw = NULL; + + other_mux_hw = composite->clock_data->is_multi_mux(hw); + + if (!other_mux_hw || clk_stm32_composite_is_enabled(other_mux_hw)) + return; + } + + spin_lock_irqsave(composite->lock, flags); + + stm32_mux_set_parent(composite->base, composite->clock_data, + composite->mux_id, MUX_SAFE_POSITION); + + spin_unlock_irqrestore(composite->lock, flags); + } +} + +static void clk_stm32_safe_restore_position_mux(struct clk_hw *hw) +{ + struct clk_stm32_composite *composite = to_clk_stm32_composite(hw); + int sel = clk_hw_get_parent_index(hw); + unsigned long flags = 0; + + spin_lock_irqsave(composite->lock, flags); + + stm32_mux_set_parent(composite->base, composite->clock_data, composite->mux_id, sel); + + spin_unlock_irqrestore(composite->lock, flags); +} + static void clk_stm32_composite_gate_endisable(struct clk_hw *hw, int enable) { struct clk_stm32_composite *composite = to_clk_stm32_composite(hw);
@@ -516,6 +564,9 @@ static int clk_stm32_composite_gate_enable(struct clk_hw *hw) clk_stm32_composite_gate_endisable(hw, 1); + if (composite->mux_id != NO_STM32_MUX && clk_stm32_has_safe_mux(hw)) + clk_stm32_safe_restore_position_mux(hw); + return 0; }
@@ -527,6 +578,9 @@ static void clk_stm32_composite_gate_disable(struct clk_hw *hw) return; clk_stm32_composite_gate_endisable(hw, 0); + + if (composite->mux_id != NO_STM32_MUX && clk_stm32_has_safe_mux(hw)) + clk_stm32_set_safe_position_mux(hw); } static void clk_stm32_composite_disable_unused(struct clk_hw *hw)
diff --git a/drivers/clk/stm32/clk-stm32-core.h b/drivers/clk/stm32/clk-stm32-core.h
index dab1b65b2537..76cffda02308 100644
--- a/drivers/clk/stm32/clk-stm32-core.h
+++ b/drivers/clk/stm32/clk-stm32-core.h@@ -84,6 +84,7 @@ int stm32_rcc_init(struct device *dev, const struct of_device_id *match_data, /* MUX define */ #define MUX_NO_RDY 0xFF +#define MUX_SAFE BIT(7) /* DIV define */ #define DIV_NO_RDY 0xFF
diff --git a/drivers/clk/stm32/clk-stm32mp13.c b/drivers/clk/stm32/clk-stm32mp13.c
index 08e3fe05d6d0..1192eee8abe4 100644
--- a/drivers/clk/stm32/clk-stm32mp13.c
+++ b/drivers/clk/stm32/clk-stm32mp13.c@@ -359,6 +359,9 @@ enum enum_mux_cfg { #define CFG_MUX(_id, _offset, _shift, _witdh)\ _CFG_MUX(_id, _offset, _shift, _witdh, MUX_NO_RDY, 0) +#define CFG_MUX_SAFE(_id, _offset, _shift, _witdh)\ + _CFG_MUX(_id, _offset, _shift, _witdh, MUX_NO_RDY, MUX_SAFE) + static const struct stm32_mux_cfg stm32mp13_muxes[] = { CFG_MUX(MUX_I2C12, RCC_I2C12CKSELR, 0, 3), CFG_MUX(MUX_LPTIM45, RCC_LPTIM45CKSELR, 0, 3),
@@ -394,10 +397,10 @@ static const struct stm32_mux_cfg stm32mp13_muxes[] = { CFG_MUX(MUX_UART6, RCC_UART6CKSELR, 0, 3), CFG_MUX(MUX_USBO, RCC_USBCKSELR, 4, 1), CFG_MUX(MUX_USBPHY, RCC_USBCKSELR, 0, 2), - CFG_MUX(MUX_FMC, RCC_FMCCKSELR, 0, 2), - CFG_MUX(MUX_QSPI, RCC_QSPICKSELR, 0, 2), - CFG_MUX(MUX_SDMMC1, RCC_SDMMC12CKSELR, 0, 3), - CFG_MUX(MUX_SDMMC2, RCC_SDMMC12CKSELR, 3, 3), + CFG_MUX_SAFE(MUX_FMC, RCC_FMCCKSELR, 0, 2), + CFG_MUX_SAFE(MUX_QSPI, RCC_QSPICKSELR, 0, 2), + CFG_MUX_SAFE(MUX_SDMMC1, RCC_SDMMC12CKSELR, 0, 3), + CFG_MUX_SAFE(MUX_SDMMC2, RCC_SDMMC12CKSELR, 3, 3), }; struct clk_stm32_securiy {
--
2.25.1
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