Hi Sergei,
On Tue, Dec 4, 2018 at 8:51 PM Sergei Shtylyov
<sergei.shtylyov@xxxxxxxxxxxxxxxxxx> wrote:
> The RPCSRC internal clock is controlled by the RPCCKCR.DIV[4:3] on all
> the R-Car gen3 SoCs except V3M (R8A77970) but the encoding of this field
> is different between SoCs; it makes sense to support the most common case
> of this encoding in the R-Car gen3 CPG driver...
>
> After adding the RPCSRC clock, we can add the RPC[D2] clocks derived from
> it and controlled by the RPCCKCR register on all the R-Car gen3 SoCs except
> V3M (R8A77970); the composite clock driver seems handy for this task, using
> the spinlock added in the previous patch...
>
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
>
> ---
> Changes in version 2:
> - merged in the RPCD2 clock support from the next patch;
> - moved in the RPCSRC clock support from the R8A77980 CPG/MSSR driver patch;
> - switched the RPC and RPCSD2 clock support to the composite clock driver;
> - changed the 1st parameter of cpg_rpc[d2]_clk_register();
> - rewrote the patch description, renamed the patch.
Thanks for the update!
> --- renesas-drivers.orig/drivers/clk/renesas/rcar-gen3-cpg.c
> +++ renesas-drivers/drivers/clk/renesas/rcar-gen3-cpg.c
> @@ -415,6 +415,90 @@ free_clock:
> return clk;
> }
>
> +struct rpc_clock {
> + struct clk_divider div;
> + struct clk_gate gate;
> + struct cpg_simple_notifier csn;
> +};
> +
> +static const struct clk_div_table cpg_rpcsrc_div_table[] = {
> + { 2, 5 }, { 3, 6 }, { 0, 0 },
> +};
> +
> +static const struct clk_div_table cpg_rpc_div_table[] = {
> + { 1, 2 }, { 3, 4 }, { 5, 6 }, { 7, 8 }, { 0, 0 },
> +};
> +
> +static struct clk * __init cpg_rpc_clk_register(const char *name,
> + void __iomem *base, const char *parent_name,
> + struct raw_notifier_head *notifiers)
> +{
> + struct rpc_clock *rpc;
> + struct clk *clk;
> +
> + rpc = kzalloc(sizeof(*rpc), GFP_KERNEL);
> + if (!rpc)
> + return ERR_PTR(-ENOMEM);
> +
> + rpc->div.reg = base + CPG_RPCCKCR;
> + rpc->div.width = 3;
> + rpc->div.table = cpg_rpc_div_table;
> + rpc->div.lock = &cpg_lock;
> +
> + rpc->gate.reg = base + CPG_RPCCKCR;
> + rpc->gate.bit_idx = 8;
> + rpc->gate.flags = CLK_GATE_SET_TO_DISABLE;
> + rpc->gate.lock = &cpg_lock;
> +
> + rpc->csn.reg = base + CPG_RPCCKCR;
> +
> + clk = clk_register_composite(NULL, name, &parent_name, 1, NULL, NULL,
> + &rpc->div.hw, &clk_divider_ops,
> + &rpc->gate.hw, &clk_gate_ops, 0);
> + if (IS_ERR(clk))
> + kfree(rpc);
> +
> + cpg_simple_notifier_register(notifiers, &rpc->csn);
> + return clk;
> +}
> +
> +static struct clk * __init cpg_rpcd2_clk_register(const char *name,
> + void __iomem *base,
> + const char *parent_name)
> +{
> + struct clk_fixed_factor *fixed;
> + struct clk_gate *gate;
> + struct clk *clk;
> +
> + fixed = kzalloc(sizeof(*fixed), GFP_KERNEL);
> + if (!fixed)
> + return ERR_PTR(-ENOMEM);
> +
> + fixed->mult = 1;
> + fixed->div = 2;
> +
> + gate = kzalloc(sizeof(*gate), GFP_KERNEL);
> + if (!gate) {
> + kfree(fixed);
> + return ERR_PTR(-ENOMEM);
> + }
Why allocate two separate structures here, instead of grouping them in a
single struct rpcd2_clock structure, like for the RPC clock?
> +
> + gate->reg = base + CPG_RPCCKCR;
> + gate->bit_idx = 9;
> + gate->flags = CLK_GATE_SET_TO_DISABLE;
> + gate->lock = &cpg_lock;
> +
> + clk = clk_register_composite(NULL, name, &parent_name, 1, NULL, NULL,
> + &fixed->hw, &clk_fixed_factor_ops,
> + &gate->hw, &clk_gate_ops, 0);
> + if (IS_ERR(clk)) {
> + kfree(fixed);
> + kfree(gate);
> + }
I first wondered why there's no notifier to save/restore the clock during system
PSCI suspend/resume, until I realized the RPC and RPCD2 clocks share the
same hardware register, so saving/restoring the register once is sufficient.
A comment (in struct rpc_clock?) explaining that would be appreciated.
The rest looks good to me.
Using the composite clock seems to have reduced LoC by ca. 60%, nice!
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
