Re: [PATCH 2/6] clk: sunxi: Add H3 clocks support

From: Jens Kuske
Date: Sun May 10 2015 - 06:57:03 EST

Hi,

On 09/05/15 13:27, Maxime Ripard wrote:
> On Wed, May 06, 2015 at 11:31:29AM +0200, Jens Kuske wrote:
>> The H3 clock control unit is similar to the those of other sun8i family
>> members like the A23.
>>
>> The AHB1 gates got split up into AHB1 and AHB2, with AHB2 clock source
>> being muxable between AHB1 and PLL6/2, but still sharing gate registers.
>> The documentation isn't totally clear about which devices belong to
>> AHB2 now, especially USB EHIC/OHIC, so it is mostly based on Allwinner
>> kernel source code.
>>
>> Signed-off-by: Jens Kuske <jenskuske@xxxxxxxxx>
>> ---
>> Documentation/devicetree/bindings/clock/sunxi.txt | 7 ++++
>> drivers/clk/sunxi/clk-sunxi.c | 46 ++++++++++++++++++++++-
>> 2 files changed, 52 insertions(+), 1 deletion(-)
>>
>> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
>> index 4fa11af..4eeb893 100644
>> --- a/Documentation/devicetree/bindings/clock/sunxi.txt
>> +++ b/Documentation/devicetree/bindings/clock/sunxi.txt
>> @@ -14,6 +14,8 @@ Required properties:
>> "allwinner,sun4i-a10-pll5-clk" - for the PLL5 clock
>> "allwinner,sun4i-a10-pll6-clk" - for the PLL6 clock
>> "allwinner,sun6i-a31-pll6-clk" - for the PLL6 clock on A31
>> + "allwinner,sun8i-h3-pll6-clk" - for the PLL6 clock on H3
>> + "allwinner,sun8i-h3-pll8-clk" - for the PLL8 clock on H3
>> "allwinner,sun9i-a80-gt-clk" - for the GT bus clock on A80
>> "allwinner,sun4i-a10-cpu-clk" - for the CPU multiplexer clock
>> "allwinner,sun4i-a10-axi-clk" - for the AXI clock
>> @@ -28,8 +30,11 @@ Required properties:
>> "allwinner,sun7i-a20-ahb-gates-clk" - for the AHB gates on A20
>> "allwinner,sun6i-a31-ar100-clk" - for the AR100 on A31
>> "allwinner,sun6i-a31-ahb1-clk" - for the AHB1 clock on A31
>> + "allwinner,sun8i-h3-ahb2-clk" - for the AHB2 clock on H3
>> "allwinner,sun6i-a31-ahb1-gates-clk" - for the AHB1 gates on A31
>> "allwinner,sun8i-a23-ahb1-gates-clk" - for the AHB1 gates on A23
>> + "allwinner,sun8i-h3-ahb1-gates-clk" - for the AHB1 gates on H3
>> + "allwinner,sun8i-h3-ahb2-gates-clk" - for the AHB2 gates on H3
>> "allwinner,sun9i-a80-ahb0-gates-clk" - for the AHB0 gates on A80
>> "allwinner,sun9i-a80-ahb1-gates-clk" - for the AHB1 gates on A80
>> "allwinner,sun9i-a80-ahb2-gates-clk" - for the AHB2 gates on A80
>> @@ -52,8 +57,10 @@ Required properties:
>> "allwinner,sun6i-a31-apb1-gates-clk" - for the APB1 gates on A31
>> "allwinner,sun7i-a20-apb1-gates-clk" - for the APB1 gates on A20
>> "allwinner,sun8i-a23-apb1-gates-clk" - for the APB1 gates on A23
>> + "allwinner,sun8i-h3-apb1-gates-clk" - for the APB1 gates on H3
>> "allwinner,sun9i-a80-apb1-gates-clk" - for the APB1 gates on A80
>> "allwinner,sun6i-a31-apb2-gates-clk" - for the APB2 gates on A31
>> + "allwinner,sun8i-h3-apb2-gates-clk" - for the APB2 gates on H3
>> "allwinner,sun8i-a23-apb2-gates-clk" - for the APB2 gates on A23
>> "allwinner,sun5i-a13-mbus-clk" - for the MBUS clock on A13
>> "allwinner,sun4i-a10-mmc-clk" - for the MMC clock
>> diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
>> index 7e1e2bd..152a1f7 100644
>> --- a/drivers/clk/sunxi/clk-sunxi.c
>> +++ b/drivers/clk/sunxi/clk-sunxi.c
>> @@ -727,6 +727,12 @@ static const struct factors_data sun5i_a13_ahb_data __initconst = {
>> .getter = sun5i_a13_get_ahb_factors,
>> };
>>
>> +static const struct factors_data sun8i_h3_pll8_data __initconst = {
>> + .enable = 31,
>> + .table = &sun6i_a31_pll6_config,
>> + .getter = sun6i_a31_get_pll6_factors,
>> +};
>
> This looks like it's just another instance of the A31 pll6.
>
> In such a case, we don't need to declare a new driver, just reuse the
> same compatible.

If I reuse pll6 for pll8 I get errors because of the .name = "pll6x2"
field, already existing clock or something like that. (And pll8 doesn't
even have a x2 version)

>
>> static const struct factors_data sun4i_apb1_data __initconst = {
>> .mux = 24,
>> .muxmask = BIT(1) | BIT(0),
>> @@ -777,6 +783,10 @@ static const struct mux_data sun6i_a31_ahb1_mux_data __initconst = {
>> .shift = 12,
>> };
>>
>> +static const struct mux_data sun8i_h3_ahb2_mux_data __initconst = {
>> + .shift = 0,
>> +};
>> +
>> static void __init sunxi_mux_clk_setup(struct device_node *node,
>> struct mux_data *data)
>> {
>> @@ -892,7 +902,7 @@ static void __init sunxi_divider_clk_setup(struct device_node *node,
>> * sunxi_gates_clk_setup() - Setup function for leaf gates on clocks
>> */
>>
>> -#define SUNXI_GATES_MAX_SIZE 64
>> +#define SUNXI_GATES_MAX_SIZE 160
>>
>> struct gates_data {
>> DECLARE_BITMAP(mask, SUNXI_GATES_MAX_SIZE);
>> @@ -926,6 +936,10 @@ static const struct gates_data sun8i_a23_ahb1_gates_data __initconst = {
>> .mask = {0x25386742, 0x2505111},
>> };
>>
>> +static const struct gates_data sun8i_h3_ahb1_gates_data __initconst = {
>> + .mask = {0x1fbc6760, 0x00701b39, 0x00000000, 0x00000000, 0x00000081},
>> +};
>> +
>
> Judging from the user manual, there's a few gates in those 0
> registers, is this normal that you don't support them?

They are holes for apb1 and apb2. Which is actually pretty ugly.

>
>> static const struct gates_data sun9i_a80_ahb0_gates_data __initconst = {
>> .mask = {0xF5F12B},
>> };
>> @@ -938,6 +952,10 @@ static const struct gates_data sun9i_a80_ahb2_gates_data __initconst = {
>> .mask = {0x9B7},
>> };
>>
>> +static const struct gates_data sun8i_h3_ahb2_gates_data __initconst = {
>> + .mask = {0xe0020000},
>> +};
>> +
>
> I don't think we should split the ahb1 and ahb2 gates here. It really
> looks like it's the same controller.
>
> The way I'm seeing it would be to have a single clock driver that
> would handle both your ahb1 and ahb2 gates.
>
> It would take two parents, ahb1 and ahb2, obviously, and would take
> register depending on the gate w'ere registering either the ahb1 or
> the ahb2 parent.
>
> It seems like there's only a handful of devices in ahb2 anyway, so
> that wouldn't make a very long list of devices to declare as childs of
> ahb2.
>

I have thought about adding a bus_gates driver for all ahb1, ahb2, apb1
and apb2 gates, as it is done in the user manual.

But it would need a pretty big parents array and result in big gate
numbers in devicetree, <&bus_gates 112> for uart0 for example.

Would this be ok?

Jens

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