[PATCHv3 3/4] clk: sunxi: Add A31 clocks support

Emilio López
2013-08-20T10:10:12Z

Hi,

El 20/08/13 03:25, Maxime Ripard escribi?:
> Hi Emilio,
>
> On Mon, Aug 19, 2013 at 05:14:57PM -0300, Emilio L?pez wrote:
>> El 05/08/13 17:43, Maxime Ripard escribi?:
>>> The A31 has a mostly different clock set compared to the other older
>>> SoCs currently supported in the Allwinner clock driver.
>>>
>>> Add support for the basic useful clocks. The other ones will come in
>>> eventually.
>>>
>>> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
>>
>> I had another quick look at it and overall it looks good to go,
>>
>> Reviewed-by: Emilio L?pez <emilio@elopez.com.ar>
>
> Thanks!
>
>>> ---
>>> Documentation/devicetree/bindings/clock/sunxi.txt | 6 +
>>> .../bindings/clock/sunxi/sun6i-a31-gates.txt | 83 ++++++++++++++
>>> drivers/clk/sunxi/clk-sunxi.c | 124 +++++++++++++++++++++
>>> 3 files changed, 213 insertions(+)
>>> create mode 100644 Documentation/devicetree/bindings/clock/sunxi/sun6i-a31-gates.txt
>>>
>>> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
>>> index b24de10..c383d12 100644
>>> --- a/Documentation/devicetree/bindings/clock/sunxi.txt
>>> +++ b/Documentation/devicetree/bindings/clock/sunxi.txt
>>> @@ -8,6 +8,7 @@ Required properties:
>>> - compatible : shall be one of the following:
>>> "allwinner,sun4i-osc-clk" - for a gatable oscillator
>>> "allwinner,sun4i-pll1-clk" - for the main PLL clock
>>> + "allwinner,sun6i-a31-pll1-clk" - for the main PLL clock on A31
>>> "allwinner,sun4i-cpu-clk" - for the CPU multiplexer clock
>>> "allwinner,sun4i-axi-clk" - for the AXI clock
>>> "allwinner,sun4i-axi-gates-clk" - for the AXI gates
>>> @@ -15,6 +16,8 @@ Required properties:
>>> "allwinner,sun4i-ahb-gates-clk" - for the AHB gates on A10
>>> "allwinner,sun5i-a13-ahb-gates-clk" - for the AHB gates on A13
>>> "allwinner,sun5i-a10s-ahb-gates-clk" - for the AHB gates on A10s
>>> + "allwinner,sun6i-a31-ahb1-mux-clk" - for the AHB1 multiplexer on A31
>>> + "allwinner,sun6i-a31-ahb1-gates-clk" - for the AHB1 gates on A31
>>> "allwinner,sun4i-apb0-clk" - for the APB0 clock
>>> "allwinner,sun4i-apb0-gates-clk" - for the APB0 gates on A10
>>> "allwinner,sun5i-a13-apb0-gates-clk" - for the APB0 gates on A13
>>> @@ -24,6 +27,9 @@ Required properties:
>>> "allwinner,sun4i-apb1-gates-clk" - for the APB1 gates on A10
>>> "allwinner,sun5i-a13-apb1-gates-clk" - for the APB1 gates on A13
>>> "allwinner,sun5i-a10s-apb1-gates-clk" - for the APB1 gates on A10s
>>> + "allwinner,sun6i-a31-apb1-gates-clk" - for the APB1 gates on A31
>>> + "allwinner,sun6i-a31-apb2-div-clk" - for the APB2 gates on A31
>>> + "allwinner,sun6i-a31-apb2-gates-clk" - for the APB2 gates on A31
>>>
>>> Required properties for all clocks:
>>> - reg : shall be the control register address for the clock.
>>> diff --git a/Documentation/devicetree/bindings/clock/sunxi/sun6i-a31-gates.txt b/Documentation/devicetree/bindings/clock/sunxi/sun6i-a31-gates.txt
>>> new file mode 100644
>>> index 0000000..fe44932
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/clock/sunxi/sun6i-a31-gates.txt
>>> @@ -0,0 +1,83 @@
>>> +Gate clock outputs
>>> +------------------
>>> +
>>> + * AHB1 gates ("allwinner,sun6i-a31-ahb1-gates-clk")
>>> +
>>> + MIPI DSI 1
>>> +
>>> + SS 5
>>> + DMA 6
>>> +
>>> + MMC0 8
>>> + MMC1 9
>>> + MMC2 10
>>> + MMC3 11
>>> +
>>> + NAND1 12
>>> + NAND0 13
>>> + SDRAM 14
>>> +
>>> + GMAC 17
>>> + TS 18
>>> + HSTIMER 19
>>> + SPI0 20
>>> + SPI1 21
>>> + SPI2 22
>>> + SPI3 23
>>> + USB_OTG 24
>>> +
>>> + EHCI0 26
>>> + EHCI1 27
>>> +
>>> + OHCI0 29
>>> + OHCI1 30
>>> + OHCI2 31
>>> + VE 32
>>> +
>>> + LCD0 36
>>> + LCD1 37
>>> +
>>> + CSI 40
>>> +
>>> + HDMI 43
>>> + DE_BE0 44
>>> + DE_BE1 45
>>> + DE_FE1 46
>>> + DE_FE1 47
>>> +
>>> + MP 50
>>> +
>>> + GPU 52
>>> +
>>> + DEU0 55
>>> + DEU1 56
>>> + DRC0 57
>>> + DRC1 58
>>> +
>>> + * APB1 gates ("allwinner,sun6i-a31-apb1-gates-clk")
>>> +
>>> + CODEC 0
>>> +
>>> + DIGITAL MIC 4
>>> + PIO 5
>>> +
>>> + DAUDIO0 12
>>> + DAUDIO1 13
>>> +
>>> + * APB2 gates ("allwinner,sun6i-a31-apb2-gates-clk")
>>> +
>>> + I2C0 0
>>> + I2C1 1
>>> + I2C2 2
>>> + I2C3 3
>>> +
>>> + UART0 16
>>> + UART1 17
>>> + UART2 18
>>> + UART3 19
>>> + UART4 20
>>> + UART5 21
>>> +
>>> +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
>>
>> If you have to respin this, I suppose you could drop the notation
>> block, as it's not being used. But don't worry otherwise.
>
> Actually, I left it here on purpose, if we ever need to add such clocks.
> That way we would have the same notation than on the other files of the
> documentation.

Ok, sounds sensible.

>>
>>> diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
>>> index cd07169..bd01a02 100644
>>> --- a/drivers/clk/sunxi/clk-sunxi.c
>>> +++ b/drivers/clk/sunxi/clk-sunxi.c
>>> @@ -125,7 +125,89 @@ static void sun4i_get_pll1_factors(u32 *freq, u32 parent_rate,
>>> *n = div / 4;
>>> }
>>>
>>> +/**
>>> + * sun6i_a31_get_pll1_factors() - calculates n, k and m factors for PLL1
>>> + * PLL1 rate is calculated as follows
>>> + * rate = parent_rate * (n + 1) * (k + 1) / (m + 1);
>>> + * parent_rate should always be 24MHz
>>> + */
>>> +static void sun6i_a31_get_pll1_factors(u32 *freq, u32 parent_rate,
>>> + u8 *n, u8 *k, u8 *m, u8 *p)
>>> +{
>>> + /*
>>> + * We can operate only on MHz, this will make our life easier
>>> + * later.
>>> + */
>>> + u32 freq_mhz = *freq / 1000000;
>>> + u32 parent_freq_mhz = parent_rate / 1000000;
>>> +
>>> + /*
>>> + * Round down the frequency to the closest multiple of either
>>> + * 6 or 16
>>> + */
>>> + u32 round_freq_6 = round_down(freq_mhz, 6);
>>> + u32 round_freq_16 = round_down(freq_mhz, 16);
>>> +
>>> + if (round_freq_6 > round_freq_16)
>>> + freq_mhz = round_freq_6;
>>> + else
>>> + freq_mhz = round_freq_16;
>>>
>>> + *freq = freq_mhz * 1000000;
>>> +
>>> + /*
>>> + * If the factors pointer are null, we were just called to
>>> + * round down the frequency.
>>> + * Exit.
>>> + */
>>> + if (n == NULL)
>>> + return;
>>> +
>>> + /* If the frequency is a multiple of 32 MHz, k is always 3 */
>>> + if (!(freq_mhz % 32))
>>> + *k = 3;
>>> + /* If the frequency is a multiple of 9 MHz, k is always 2 */
>>> + else if (!(freq_mhz % 9))
>>> + *k = 2;
>>> + /* If the frequency is a multiple of 8 MHz, k is always 1 */
>>> + else if (!(freq_mhz % 8))
>>> + *k = 1;
>>> + /* Otherwise, we don't use the k factor */
>>> + else
>>> + *k = 0;
>>> +
>>> + /*
>>> + * If the frequency is a multiple of 2 but not a multiple of
>>> + * 3, m is 3. This is the first time we use 6 here, yet we
>>> + * will use it on several other places.
>>> + * We use this number because it's the lowest frequency we can
>>> + * generate (with n = 0, k = 0, m = 3), so every other frequency
>>> + * somehow relates to this frequency.
>>> + */
>>> + if ((freq_mhz % 6) == 2 || (freq_mhz % 6) == 4)
>>> + *m = 2;
>>> + /*
>>> + * If the frequency is a multiple of 6MHz, but the factor is
>>> + * odd, m will be 3
>>> + */
>>> + else if ((freq_mhz / 6) & 1)
>>> + *m = 3;
>>> + /* Otherwise, we end up with m = 1 */
>>> + else
>>> + *m = 1;
>>> +
>>> + /* Calculate n thanks to the above factors we already got */
>>> + *n = freq_mhz * (*m + 1) / ((*k + 1) * parent_freq_mhz) - 1;
>>> +
>>> + /*
>>> + * If n end up being outbound, and that we can still decrease
>>> + * m, do it.
>>> + */
>>> + if ((*n + 1) > 31 && (*m + 1) > 1) {
>>> + *n = (*n + 1) / 2 - 1;
>>> + *m = (*m + 1) / 2 - 1;
>>> + }
>>> +}
>>>
>>
>> And again, I'm purely nitpicking, but it'd be good to keep the space
>> between functions consistent.
>
> Hmmm, what space? The coding style documentation clearly states that
> there should be only one line between two functions.

Hmm, I wasn't aware of that. I was using three lines between functions
with their struct sets to keep some kind of visual separation between
code for different clocks. But if the coding style dictates that, we can
switch to it.

Cheers,

Emilio