[PATCH 1/6] clk: sunxi: Add support for AXI, AHB, APB0 and APB1 gates
Emilio López
emilio at elopez.com.ar
Mon Mar 25 06:17:37 EDT 2013
Hi Maxime,
El 25/03/13 06:43, Maxime Ripard escribió:
> Hi Emilio,
>
> I have a few comments below,
>
> Le 22/03/2013 15:20, Emilio López a écrit :
>> This patchset adds DT support for all the AXI, AHB, APB0 and APB1
>> gates present on sunxi SoCs.
>>
>> Signed-off-by: Emilio López <emilio at elopez.com.ar>
>> ---
>> Documentation/devicetree/bindings/clock/sunxi.txt | 108 +++++++++++++++++++++-
>> drivers/clk/sunxi/clk-sunxi.c | 90 +++++++++++++++++-
>> 2 files changed, 196 insertions(+), 2 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
>> index b23cfbd..c5432c4 100644
>> --- a/Documentation/devicetree/bindings/clock/sunxi.txt
>> +++ b/Documentation/devicetree/bindings/clock/sunxi.txt
>> @@ -10,15 +10,23 @@ Required properties:
>> "allwinner,sunxi-pll1-clk" - for the main PLL clock
>> "allwinner,sunxi-cpu-clk" - for the CPU multiplexer clock
>> "allwinner,sunxi-axi-clk" - for the sunxi AXI clock
>> + "allwinner,sunxi-axi-gates-clk" - for the AXI gates
>> "allwinner,sunxi-ahb-clk" - for the sunxi AHB clock
>> + "allwinner,sunxi-ahb-gates-clk" - for the AHB gates
>> "allwinner,sunxi-apb0-clk" - for the sunxi APB0 clock
>> + "allwinner,sunxi-apb0-gates-clk" - for the APB0 gates
>> "allwinner,sunxi-apb1-clk" - for the sunxi APB1 clock
>> "allwinner,sunxi-apb1-mux-clk" - for the sunxi APB1 clock muxing
>> + "allwinner,sunxi-apb1-gates-clk" - for the APB1 gates
>
> It has been pointed to me that the usual way of dealing with compatible
> IPs in several generation of SoC in device tree is usually to use the
> oldest SoC name to support it, and not some generic term like we use.
>
> I'm currently struggling while doing some work on the A31, where some
> IPs differ in a significant way from the A10/A13, and we can't just use
> sunxi anymore.
>
> I have a patchset that renames every other IP we have doing this, but
> could you rename your compatible strings to allwinner,sun4i* as a first
> patch for the already existing clocks, and use that prefix in the
> following patches as well? Moreover, since it has been mostly tested on
> an A10, if the IP came to differ to some aspect in the A13, it will make
> our life easier as well.
Ok, I'll do so.
>
>>
>> Required properties for all clocks:
>> - reg : shall be the control register address for the clock.
>> - clocks : shall be the input parent clock(s) phandle for the clock
>> -- #clock-cells : from common clock binding; shall be set to 0.
>> +- #clock-cells : from common clock binding; shall be set to 0 except for
>> + "allwinner,sunxi-*-gates-clk" where it shall be set to 1
>> +
>> +Additionally, "allwinner,sunxi-*-gates-clk" clocks require:
>> +- clock-output-names : the corresponding gate names that the clock controls
>>
>> For example:
>>
>> @@ -42,3 +50,101 @@ cpu: cpu at 01c20054 {
>> reg = <0x01c20054 0x4>;
>> clocks = <&osc32k>, <&osc24M>, <&pll1>;
>> };
>> +
>> +
>> +
>> +Gate clock outputs
>> +
>> +The "allwinner,sunxi-*-gates-clk" clocks provide several gatable outputs;
>> +their corresponding offsets are listed below:
>> +
>> + * AXI gates ("allwinner,sunxi-axi-gates-clk")
>> +
>> + DRAM 0
>> +
>> + * AHB gates ("allwinner,sunxi-ahb-gates-clk")
>> +
>> + USB0 0
>> + EHCI0 1
>> + OHCI0 2*
>> + EHCI1 3
>> + OHCI1 4*
>> + SS 5
>> + DMA 6
>> + BIST 7
>> + MMC0 8
>> + MMC1 9
>> + MMC2 10
>> + MMC3 11
>> + MS 12**
>> + NAND 13
>> + SDRAM 14
>> +
>> + ACE 16
>> + EMAC 17
>
> Hmmm, this makes me thinking that I used wemac in the pinctrl driver,
> and that it's not really consistent with the datasheet, what you have
> here, and what I did in the EMAC driver. I'll need to change that...
>
>> + TS 18
>> +
>> + SPI0 20
>> + SPI1 21
>> + SPI2 22
>> + SPI3 23
>> + PATA 24
>> + SATA 25**
>> + GPS 26*
>> +
>> + VE 32
>> + TVD 33
>> + TVE0 34
>> + TVE1 35
>> + LCD0 36
>> + LCD1 37
>> +
>> + CSI0 40
>> + CSI1 41
>> +
>> + HDMI 43
>> + DE_BE0 44
>> + DE_BE1 45
>> + DE_FE0 46
>> + DE_FE1 47
>> +
>> + MP 50
>> +
>> + MALI400 52
>> +
>> + * APB0 gates ("allwinner,sunxi-apb0-gates-clk")
>> +
>> + CODEC 0
>> + SPDIF 1*
>> + AC97 2
>> + IIS 3
>> +
>> + PIO 5
>> + IR0 6
>> + IR1 7
>> +
>> + KEYPAD 10
>> +
>> + * APB1 gates ("allwinner,sunxi-apb1-gates-clk")
>> +
>> + TWI0 0
>> + TWI1 1
>> + TWI2 2
>
> I'd rather see here I2C. I know that it's called TWI in the datasheet,
> but the term I2C is more commonly used in the kernel.
Ok, I'll change it. Do you want me to rename the gate names on the DT
too to match? ("apb1_twi0" -> "apb1_i2c0")
>
>> + CAN 4
>> + SCR 5
>> + PS20 6
>> + PS21 7
>> +
>> + UART0 16
>> + UART1 17
>> + UART2 18
>> + UART3 19
>> + UART4 20
>> + UART5 21
>> + UART6 22
>> + UART7 23
>> +
>> +Notation:
>> + [*]: The datasheet didn't mention these, but they are present on AW code
>> + [**]: The datasheet had this marked as "NC" but they are used on AW code
>
> I'm really happy with the general documentation, thanks for this.
> However, all of this is true only for the A10, could you mention it
> somewhere?
I could add a note saying so. We could also rename this file to
sun4i.txt and then and add a sun5i.txt with the A13 gate descriptions
too; what would you prefer?
Thanks for the review,
Emilio
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