Re: [PATCH v2 4/6] clk: sunxi-ng: add support for the Allwinner H6 CCU

From: Icenowy Zheng
Date: Wed Feb 07 2018 - 04:11:27 EST




ä 2018å2æ7æ GMT+08:00 äå5:02:10, Maxime Ripard <maxime.ripard@xxxxxxxxxxx> åå:
>Hi,
>
>On Sat, Feb 03, 2018 at 11:49:40PM +0800, Icenowy Zheng wrote:
>> + /* Force the output divider of video PLLs to 0 */
>> + for (i = 0; i < ARRAY_SIZE(pll_video_regs); i++) {
>> + val = readl(reg + pll_video_regs[i]);
>> + val &= ~BIT(0);
>> + writel(val, reg + pll_video_regs[i]);
>> + }
>
>Why?

According to the manual the output divider here is
test only, and for daily use it should be 0.

>
>> + /* Force OHCI 12M clock sources to 00 (12MHz divided from 48MHz) */
>> + for (i = 0; i < ARRAY_SIZE(usb2_clk_regs); i++) {
>> + val = readl(reg + usb2_clk_regs[i]);
>> + val &= ~GENMASK(25, 24);
>> + writel (val, reg + usb2_clk_regs[i]);
>> + }
>
>Why?

Just make them have a sure working parent. Why this
muxs exist is still mysterious.

>
>> + /*
>> + * Force the post-divider of pll-video to 8 and the output divider

oh here's a typo -- it's audio, not video.

>> + * of it to 1.
>> + */
>> + val = readl(reg + SUN50I_H6_PLL_AUDIO_REG);
>> + val &= ~(GENMASK(21, 16) | BIT(0));
>> + writel(val | (7 << 16), reg + SUN50I_H6_PLL_AUDIO_REG);
>
>Why?

See the comments about pll-audio in the former sources :-)

>> diff --git a/include/dt-bindings/clock/sun50i-h6-ccu.h
>b/include/dt-bindings/clock/sun50i-h6-ccu.h
>> new file mode 100644
>> index 000000000000..f7ddb241012c
>> --- /dev/null
>> +++ b/include/dt-bindings/clock/sun50i-h6-ccu.h
>> @@ -0,0 +1,125 @@
>> +/*
>> + * Copyright (C) 2017 Icenowy Zheng <icenowy@xxxxxxx>
>> + *
>> + * SPDX-License-Identifier: (GPL-2.0+ or MIT)
>> + */
>> +
>> +#ifndef _DT_BINDINGS_CLK_SUN50I_H6_H_
>> +#define _DT_BINDINGS_CLK_SUN50I_H6_H_
>> +
>> +#define CLK_PLL_PERIPH0 3
>
>Why is that needed?

Parent of AR100 clock in PRCM.

>
>> +
>> +#define CLK_CPUX 21
>> +
>> +#define CLK_APB1 26
>
>Same thing here

As discussed in v1, the APB bus clock is used for PIO.

>
>> +
>> +#define CLK_DE 29
>> +#define CLK_BUS_DE 30
>> +#define CLK_DEINTERLACE 31
>> +#define CLK_BUS_DEINTERLACE 32
>> +#define CLK_GPU 33
>> +#define CLK_BUS_GPU 34
>> +#define CLK_CE 35
>> +#define CLK_BUS_CE 36
>> +#define CLK_VE 37
>> +#define CLK_BUS_VE 38
>> +#define CLK_EMCE 39
>> +#define CLK_BUS_EMCE 40
>> +#define CLK_VP9 41
>> +#define CLK_BUS_VP9 42
>> +#define CLK_BUS_DMA 43
>> +#define CLK_BUS_MSGBOX 44
>> +#define CLK_BUS_SPINLOCK 45
>> +#define CLK_BUS_HSTIMER 46
>> +#define CLK_AVS 47
>> +#define CLK_BUS_DBG 48
>> +#define CLK_BUS_PSI 49
>> +#define CLK_BUS_PWM 50
>> +#define CLK_BUS_IOMMU 51
>> +
>> +#define CLK_MBUS_DMA 53
>> +#define CLK_MBUS_VE 54
>> +#define CLK_MBUS_CE 55
>> +#define CLK_MBUS_TS 56
>> +#define CLK_MBUS_NAND 57
>> +#define CLK_MBUS_CSI 58
>> +#define CLK_MBUS_DEINTERLACE 59
>> +
>> +#define CLK_NAND0 61
>> +#define CLK_NAND1 62
>> +#define CLK_BUS_NAND 63
>> +#define CLK_MMC0 64
>> +#define CLK_MMC1 65
>> +#define CLK_MMC2 66
>> +#define CLK_BUS_MMC0 67
>> +#define CLK_BUS_MMC1 68
>> +#define CLK_BUS_MMC2 69
>> +#define CLK_BUS_UART0 70
>> +#define CLK_BUS_UART1 71
>> +#define CLK_BUS_UART2 72
>> +#define CLK_BUS_UART3 73
>> +#define CLK_BUS_I2C0 74
>> +#define CLK_BUS_I2C1 75
>> +#define CLK_BUS_I2C2 76
>> +#define CLK_BUS_I2C3 77
>> +#define CLK_BUS_SCR0 78
>> +#define CLK_BUS_SCR1 79
>> +#define CLK_SPI0 80
>> +#define CLK_SPI1 81
>> +#define CLK_BUS_SPI0 82
>> +#define CLK_BUS_SPI1 83
>> +#define CLK_BUS_EMAC 84
>> +#define CLK_TS 85
>> +#define CLK_BUS_TS 86
>> +#define CLK_IR_TX 87
>> +#define CLK_BUS_IR_TX 88
>> +#define CLK_BUS_THS 89
>> +#define CLK_I2S3 90
>> +#define CLK_I2S0 91
>> +#define CLK_I2S1 92
>> +#define CLK_I2S2 93
>> +#define CLK_BUS_I2S0 94
>> +#define CLK_BUS_I2S1 95
>> +#define CLK_BUS_I2S2 96
>> +#define CLK_BUS_I2S3 97
>> +#define CLK_SPDIF 98
>> +#define CLK_BUS_SPDIF 99
>> +#define CLK_DMIC 100
>> +#define CLK_BUS_DMIC 101
>> +#define CLK_AUDIO_HUB 102
>> +#define CLK_BUS_AUDIO_HUB 103
>> +#define CLK_USB_OHCI0 104
>> +#define CLK_USB_PHY0 105
>> +#define CLK_USB_PHY1 106
>> +#define CLK_USB_OHCI3 107
>> +#define CLK_USB_PHY3 108
>> +#define CLK_USB_HSIC_12M 109
>> +#define CLK_USB_HSIC 110
>> +#define CLK_BUS_OHCI0 111
>> +#define CLK_BUS_OHCI3 112
>> +#define CLK_BUS_EHCI0 113
>> +#define CLK_BUS_XHCI 114
>> +#define CLK_BUS_EHCI3 115
>> +#define CLK_BUS_OTG 116
>> +#define CLK_PCIE_REF_100M 117
>> +#define CLK_PCIE_REF 118
>> +#define CLK_PCIE_REF_OUT 119
>> +#define CLK_PCIE_MAXI 120
>> +#define CLK_PCIE_AUX 121
>
>Dito.

I think AUX clock is used in PCIe code.

BTW the REF_100M clock is intermediate, and
does't need to be exported. Will fix it in the next version.

>
>> +#define CLK_BUS_PCIE 122
>> +#define CLK_HDMI 123
>> +#define CLK_HDMI_CEC 124
>> +#define CLK_BUS_HDMI 125
>> +#define CLK_BUS_TCON_TOP 126
>
>Ditto.

TCON_TOP is not a clock parent -- it's a dedicated hw
part which controlls the connection between
DE2/3 mixers and TCONs.

>
>Remember, you should only expose here the clocks that devices are
>going to use, and remove as much intermediate clocks as possible.
>
>If you're unsure, keep them out of the dt-binding include, we can
>always move one to the dt-binding header, while the other way isn't
>possible.