On Tue, Mar 10, 2020 at 08:44:38PM +0300, Dmitry Osipenko wrote:
> 10.03.2020 18:19, Thierry Reding пишет:
> > From: Joseph Lo <josephl@xxxxxxxxxx>
> >
> > The EMC clock needs to carefully coordinate with the EMC controller
> > programming to make sure external memory can be properly clocked. Do so
> > by hooking up the EMC clock with an EMC provider that will specify which
> > rates are supported by the EMC and provide a callback to use for setting
> > the clock rate at the EMC.
> >
> > Based on work by Peter De Schrijver <pdeschrijver@xxxxxxxxxx>.
> >
> > Signed-off-by: Joseph Lo <josephl@xxxxxxxxxx>
> > Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
> > ---
> > Changes in v5:
> > - major rework and cleanup
>
> ...
> > +static u8 tegra210_clk_emc_get_parent(struct clk_hw *hw)
> > +{
> > + struct tegra210_clk_emc *emc = to_tegra210_clk_emc(hw);
> > + u32 value;
> > + u8 src;
> > +
> > + value = readl_relaxed(emc->regs + CLK_SOURCE_EMC);
> > + src = (value >> CLK_SOURCE_EMC_2X_CLK_SRC_SHIFT) &
> > + CLK_SOURCE_EMC_2X_CLK_SRC_MASK;
>
> What about to use a generic FIELD_GET/PREP()?
Done.
> > +static int tegra210_clk_emc_set_rate(struct clk_hw *hw, unsigned long rate,
> > + unsigned long parent_rate)
> > +{
> > + struct tegra210_clk_emc *emc = to_tegra210_clk_emc(hw);
> > + struct tegra210_clk_emc_provider *provider = emc->provider;
> > + struct tegra210_clk_emc_config *config;
> > + struct device *dev = provider->dev;
> > + struct clk_hw *old, *new, *parent;
> > + u8 old_idx, new_idx, index;
> > + struct clk *clk;
> > + unsigned int i;
> > + int err;
> > +
> > + if (!provider || !provider->configs || provider->num_configs == 0)
> > + return -EINVAL;
>
> Why all these checks are needed? I don't think it ever could fail,
> couldn't it?
This could fail if no EMC provider is attached, which happens, for
example, when the EMC driver is not loaded.
>
> > +static int emc_table_lookup(struct tegra_emc *emc, unsigned long rate)
> > +{
> > + int i;
>
> unsigned int
>
> Same for all other occurrences in the code.
This was fixed automatically after I fixed the rebase issues.
Thierry
Attachment:
signature.asc
Description: PGP signature
