Re: [PATCH v2 02/10] clk: sunxi: Add support for multiple parents to gates

Jens Kuske
2015-05-18T10:09:15Z

Hi,

On 05/17/15 14:50, Maxime Ripard wrote:
> Hi Jens,
>
> On Fri, May 15, 2015 at 06:38:52PM +0200, Jens Kuske wrote:
>> Some newer sunxi SoCs (A83T, H3) don't have individual registers for
>> AHB1, APB1 and APB2 gates anymore, but one big bus gates area where each
>> gate can have a different parent.
>>
>> The current clock driver sets the same parent for all gates in a group.
>> This commit adds a new parents field to the gates_data structure, which
>> allows us to specify an array of parent indices for every single gate.
>>
>> Signed-off-by: Jens Kuske <jenskuske@gmail.com>
>> ---
>> drivers/clk/sunxi/clk-sunxi.c | 12 +++++++++++-
>> 1 file changed, 11 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
>> index 9a82f17..17cba4d 100644
>> --- a/drivers/clk/sunxi/clk-sunxi.c
>> +++ b/drivers/clk/sunxi/clk-sunxi.c
>> @@ -898,6 +898,8 @@ static void __init sunxi_divider_clk_setup(struct device_node *node,
>>
>> struct gates_data {
>> DECLARE_BITMAP(mask, SUNXI_GATES_MAX_SIZE);
>> + /* If used, ARRAY_SIZE(parents) has to be >= bitmap_weight(mask) */
>> + const u8 *parents;
>> };
>>
>> static const struct gates_data sun4i_axi_gates_data __initconst = {
>> @@ -1000,16 +1002,21 @@ static void __init sunxi_gates_clk_setup(struct device_node *node,
>> struct gates_data *data)
>> {
>> struct clk_onecell_data *clk_data;
>> + const char *parents[SUNXI_MAX_PARENTS];
>> const char *clk_parent;
>> const char *clk_name;
>> void __iomem *reg;
>> + int npar = 0;
>> int qty;
>> int i = 0;
>> int j = 0;
>>
>> reg = of_iomap(node, 0);
>>
>> - clk_parent = of_clk_get_parent_name(node, 0);
>> + while (npar < SUNXI_MAX_PARENTS &&
>> + (parents[npar] = of_clk_get_parent_name(node, npar)) != NULL)
>> + npar++;
>> + clk_parent = parents[0];
>>
>> /* Worst-case size approximation and memory allocation */
>> qty = find_last_bit(data->mask, SUNXI_GATES_MAX_SIZE);
>> @@ -1026,6 +1033,9 @@ static void __init sunxi_gates_clk_setup(struct device_node *node,
>> of_property_read_string_index(node, "clock-output-names",
>> j, &clk_name);
>>
>> + if (data->parents && !WARN_ON(data->parents[j] >= npar))
>> + clk_parent = parents[data->parents[j]];
>> +
>
> I'm currently removing that code, so I was more expecting a new
> standalone driver for that clock.

How do you want to replace that code? To me this looks like a good way
to set up all the different gates sunxi has.

Jens