lkml.org 
[lkml]   [2018]   [Jan]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH] clk: aspeed: Handle inverse polarity of USB port 1 clock gate
On Thu, Jan 11, 2018 at 9:48 PM, Benjamin Herrenschmidt
<benh@kernel.crashing.org> wrote:
> 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@kernel.crashing.org>
> --
>
> 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.

Looks good. I gave this a spin on the ast2500 and the existing
functionality worked fine. I don't have local access to test USB at
the moment.

Reviewed-by: Joel Stanley <joel@jms.id.au>

Cheers,

Joel

>
> ---
> 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);
>
>

\
 
 \ /
  Last update: 2018-01-15 17:51    [W:0.044 / U:3.364 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site