[PATCH] clk: sunxi: gmac-tx-clk mux is not a CLK_MUX_INDEX_BIT mux

[Chen-Yu Tsai]

Hi,

On Sun, Nov 16, 2014 at 4:56 AM, Hans de Goede <hdegoede at redhat.com> wrote:
> A CLK_MUX_INDEX_BIT mux has one bit per parent, but the sun7i-a20-gmac-clk
> has 2 bits selecting between 3 possible parents using values of 0, 1, 2,
> which makes it a regular mux which should not have CLK_MUX_INDEX_BIT set in
> its flag.
>
> However we do not support parent 1 (an external clock), so use a table to
> select parent 0 or 2, which are the 2 parents we support.
>
> Note this has not been causing any issues sofar, because we start with a
> parent setting of parent 0, and only ever re-parent to parent 2 (for which
> we use an index of 1 as we skip parent 1) and with CLK_MUX_INDEX_BIT set
> we write a value of 2 for index 1.

We never use parent 1, and some hardware doesn't even have it. So back
then I went for CLK_MUX_INDEX_BIT to simplify it. Guess it's not the best
way to do it.

> Tested on both a cubietruck (which uses rgmii mode) as well as a cs908
> (an a31s board which uses mii mode).
>
> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
> ---
>  drivers/clk/sunxi/clk-a20-gmac.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clk/sunxi/clk-a20-gmac.c b/drivers/clk/sunxi/clk-a20-gmac.c
> index 5296fd6..0dcf4f2 100644
> --- a/drivers/clk/sunxi/clk-a20-gmac.c
> +++ b/drivers/clk/sunxi/clk-a20-gmac.c
> @@ -53,6 +53,11 @@ static DEFINE_SPINLOCK(gmac_lock);
>  #define SUN7I_A20_GMAC_MASK    0x3
>  #define SUN7I_A20_GMAC_PARENTS 2
>
> +static u32 sun7i_a20_gmac_mux_table[SUN7I_A20_GMAC_PARENTS] = {
> +       0x00, /* Select mii_phy_tx_clk */
> +       0x02, /* Select gmac_int_tx_clk */
> +};
> +
>  static void __init sun7i_a20_gmac_clk_setup(struct device_node *node)
>  {
>         struct clk *clk;
> @@ -90,7 +95,7 @@ static void __init sun7i_a20_gmac_clk_setup(struct device_node *node)
>         gate->lock = &gmac_lock;
>         mux->reg = reg;
>         mux->mask = SUN7I_A20_GMAC_MASK;
> -       mux->flags = CLK_MUX_INDEX_BIT;
> +       mux->table = sun7i_a20_gmac_mux_table;
>         mux->lock = &gmac_lock;
>
>         clk = clk_register_composite(NULL, clk_name,
> --
> 2.1.0
>