[PATCH] clk: aspeed: Handle inverse polarity of USB port 1 clock gate

From: Benjamin Herrenschmidt
Date: Fri Jan 12 2018 - 00:48:22 EST


The USB port 1 clock gate control has an inversed polarity
from all the other clock gates in the chip. This makes the
aspeed_clk_{enable,disable} functions honor the flag
CLK_GATE_SET_TO_DISABLE and set that flag appropriately
so it's set for all clocks except USB port 1.

Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
--

I chose not to add a column to the table for that one special
case. If future chips start growing more of these, we should
consider adding this to the table instead.

Without this, USB port 1 doesn't work properly with the new
clk driver.

---
drivers/clk/clk-aspeed.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/clk-aspeed.c b/drivers/clk/clk-aspeed.c
index 6fb344730cea..f5dc5101174e 100644
--- a/drivers/clk/clk-aspeed.c
+++ b/drivers/clk/clk-aspeed.c
@@ -211,6 +211,7 @@ static int aspeed_clk_enable(struct clk_hw *hw)
unsigned long flags;
u32 clk = BIT(gate->clock_idx);
u32 rst = BIT(gate->reset_idx);
+ u32 enval;

spin_lock_irqsave(gate->lock, flags);

@@ -223,7 +224,8 @@ static int aspeed_clk_enable(struct clk_hw *hw)
}

/* Enable clock */
- regmap_update_bits(gate->map, ASPEED_CLK_STOP_CTRL, clk, 0);
+ enval = (gate->flags & CLK_GATE_SET_TO_DISABLE) ? 0 : clk;
+ regmap_update_bits(gate->map, ASPEED_CLK_STOP_CTRL, clk, enval);

if (gate->reset_idx >= 0) {
/* A delay of 10ms is specified by the ASPEED docs */
@@ -243,10 +245,12 @@ static void aspeed_clk_disable(struct clk_hw *hw)
struct aspeed_clk_gate *gate = to_aspeed_clk_gate(hw);
unsigned long flags;
u32 clk = BIT(gate->clock_idx);
+ u32 enval;

spin_lock_irqsave(gate->lock, flags);

- regmap_update_bits(gate->map, ASPEED_CLK_STOP_CTRL, clk, clk);
+ enval = (gate->flags & CLK_GATE_SET_TO_DISABLE) ? clk : 0;
+ regmap_update_bits(gate->map, ASPEED_CLK_STOP_CTRL, clk, enval);

spin_unlock_irqrestore(gate->lock, flags);
}
@@ -478,7 +482,12 @@ static int aspeed_clk_probe(struct platform_device *pdev)

for (i = 0; i < ARRAY_SIZE(aspeed_gates); i++) {
const struct aspeed_gate_data *gd = &aspeed_gates[i];
+ u32 gate_flags;

+ /* Special case: the USB port 1 clock (bit 14) is always
+ * working the opposite way from the other ones.
+ */
+ gate_flags = (gd->clock_idx == 14) ? 0 : CLK_GATE_SET_TO_DISABLE;
hw = aspeed_clk_hw_register_gate(dev,
gd->name,
gd->parent_name,
@@ -486,7 +495,7 @@ static int aspeed_clk_probe(struct platform_device *pdev)
map,
gd->clock_idx,
gd->reset_idx,
- CLK_GATE_SET_TO_DISABLE,
+ gate_flags,
&aspeed_clk_lock);
if (IS_ERR(hw))
return PTR_ERR(hw);