Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1590657 > unrolled thread

Re: [linux-sunxi] Re: [PATCH 2/4] clk: sunxi-ng: Add sun7i-a20 CCU driver

Started byPriit Laes <plaes@plaes.org>
First post2017-03-01 23:20 +0100
Last post2017-03-02 16:40 +0100
Articles 3 — 3 participants

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.


Contents

  Re: [linux-sunxi] Re: [PATCH 2/4] clk: sunxi-ng: Add sun7i-a20 CCU  driver Priit Laes <plaes@plaes.org> - 2017-03-01 23:20 +0100
    Re: [linux-sunxi] Re: [PATCH 2/4] clk: sunxi-ng: Add sun7i-a20 CCU  driver Maxime Ripard <maxime.ripard@free-electrons.com> - 2017-03-02 15:30 +0100
      Re: [linux-sunxi] Re: [PATCH 2/4] clk: sunxi-ng: Add sun7i-a20 CCU driver Chen-Yu Tsai <wens@csie.org> - 2017-03-02 16:40 +0100

#1590657 — Re: [linux-sunxi] Re: [PATCH 2/4] clk: sunxi-ng: Add sun7i-a20 CCU driver

FromPriit Laes <plaes@plaes.org>
Date2017-03-01 23:20 +0100
SubjectRe: [linux-sunxi] Re: [PATCH 2/4] clk: sunxi-ng: Add sun7i-a20 CCU driver
Message-ID<tgkLf-17l-3@gated-at.bofh.it>
On Tue, 2017-02-28 at 09:21 +0100, Maxime Ripard wrote:
> Hi,
> 
> On Mon, Feb 27, 2017 at 11:09:12PM +0200, Priit Laes wrote:
> > Introduce a clock controller driver for sun7i A20 SoC.
> > 
> > > > Signed-off-by: Priit Laes <plaes@plaes.org>
> > ---
> >  drivers/clk/sunxi-ng/Kconfig         |   11 +
> >  drivers/clk/sunxi-ng/Makefile        |    1 +
> >  drivers/clk/sunxi-ng/ccu-sun7i-a20.c | 1068 ++++++++++++++++++++++++++++++++++
> >  drivers/clk/sunxi-ng/ccu-sun7i-a20.h |  121 ++++
> >  4 files changed, 1201 insertions(+)
> >  create mode 100644 drivers/clk/sunxi-ng/ccu-sun7i-a20.c
> >  create mode 100644 drivers/clk/sunxi-ng/ccu-sun7i-a20.h
> > 
> > diff --git a/drivers/clk/sunxi-ng/Kconfig b/drivers/clk/sunxi-ng/Kconfig
> > index 695bbf9..4f436ab 100644
> > --- a/drivers/clk/sunxi-ng/Kconfig
> > +++ b/drivers/clk/sunxi-ng/Kconfig
> > @@ -85,6 +85,17 @@ config SUN6I_A31_CCU
> > > >  	select SUNXI_CCU_PHASE
> > > >  	default MACH_SUN6I
> >  
> > +config SUN7I_A20_CCU
> > > > +	bool "Support for the Allwinner A20 CCU"
> > > > +	select SUNXI_CCU_DIV
> > > > +	select SUNXI_CCU_MULT
> > > > +	select SUNXI_CCU_NK
> > > > +	select SUNXI_CCU_NKM
> > > > +	select SUNXI_CCU_NM
> > > > +	select SUNXI_CCU_MP
> > > > +	select SUNXI_CCU_PHASE
> > > > +	default MACH_SUN7I
> > +
> >  config SUN8I_A23_CCU
> > > >  	bool "Support for the Allwinner A23 CCU"
> > > >  	select SUNXI_CCU_DIV
> > diff --git a/drivers/clk/sunxi-ng/Makefile b/drivers/clk/sunxi-ng/Makefile
> > index 6feaac0..bedda5b 100644
> > --- a/drivers/clk/sunxi-ng/Makefile
> > +++ b/drivers/clk/sunxi-ng/Makefile
> > > > @@ -21,6 +21,7 @@ obj-$(CONFIG_SUNXI_CCU_MP)	+= ccu_mp.o
> > > >  obj-$(CONFIG_SUN50I_A64_CCU)	+= ccu-sun50i-a64.o
> > > >  obj-$(CONFIG_SUN5I_CCU)		+= ccu-sun5i.o
> > > >  obj-$(CONFIG_SUN6I_A31_CCU)	+= ccu-sun6i-a31.o
> > > > +obj-$(CONFIG_SUN7I_A20_CCU)	+= ccu-sun7i-a20.o
> > > >  obj-$(CONFIG_SUN8I_A23_CCU)	+= ccu-sun8i-a23.o
> > > >  obj-$(CONFIG_SUN8I_A33_CCU)	+= ccu-sun8i-a33.o
> > > >  obj-$(CONFIG_SUN8I_H3_CCU)	+= ccu-sun8i-h3.o
> > diff --git a/drivers/clk/sunxi-ng/ccu-sun7i-a20.c b/drivers/clk/sunxi-ng/ccu-sun7i-a20.c
> > new file mode 100644
> > index 0000000..90d2f13
> > --- /dev/null
> > +++ b/drivers/clk/sunxi-ng/ccu-sun7i-a20.c
> > @@ -0,0 +1,1068 @@
> > +/*
> > + * Copyright (c) 2017 Priit Laes. All rights reserved.
> > + *
> > + * This software is licensed under the terms of the GNU General Public
> > + * License version 2, as published by the Free Software Foundation, and
> > + * may be copied, distributed, and modified under those terms.
> > + *
> > + * This program is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > + * GNU General Public License for more details.
> > + */
> > +
> > +#include <linux/clk-provider.h>
> > +#include <linux/of_address.h>
> > +
> > +#include "ccu_common.h"
> > +#include "ccu_reset.h"
> > +
> > +#include "ccu_div.h"
> > +#include "ccu_gate.h"
> > +#include "ccu_mp.h"
> > +#include "ccu_mult.h"
> > +#include "ccu_nk.h"
> > +#include "ccu_nkm.h"
> > +#include "ccu_nkmp.h"
> > +#include "ccu_nm.h"
> > +#include "ccu_phase.h"
> > +
> > +#include "ccu-sun7i-a20.h"
> > +
> > +/*
> > + * PLL1 - Core clock
> > + *
> > + * TODO: sigma-delta pattern bits 2 & 3
> > + * TODO: PLL1 tuning register
> 
> I don't think we need those TODO's at all, and these comments too. If
> the clock name is good enough (and it is), it's redundant.

Ok, will clean them up.

> 
> > + */
> > 
[...]
> > +};
> > +
> > +/* PLL2 - Audio clock */
> > +static struct ccu_nm pll_audio_base_clk = {
> > > > > > +	.enable		= BIT(31),
> > > > > > +	.n		= _SUNXI_CCU_MULT_OFFSET(8, 7, 0),
> > > > > > +	.m		= _SUNXI_CCU_DIV_OFFSET(0, 5, 0),
> > > > > > +	.common		= {
> > > > > > +		.reg		= 0x008,
> > > > > > +		.hw.init	= CLK_HW_INIT("pll-audio-base",
> > > > +					      "hosc",
> > > > +					      &ccu_nm_ops,
> > > > +					      0),
> > > > +	},
> > +
> > +};
> 
> You're forgetting the post-divider here

It's hardcoded to 4 during ccu initialization, similar to what is done
on the other SoCs (A13, A31..).

> 
> > +/* TODO: pll8 gpu 0x040 */
> 
> Please add all the clocks.

I'm not really comfortable adding clocks for blocks that currently lack
drivers.

> > +/* BIT(21 .. 31) - reserved */
> 
> I'm not sure we need those comments either.
> 
> > +/*
> > + * TODO: SATA clock also supports external clock as parent.
> > + * Currently we default to using PLL6 SATA gate.
> > + */
> 
> Which external clock? It should be modelled anyway. If we have a
> dependency on some other clock, it should be in our DT binding, and
> listed in the mux there.
> 
> Otherwise, the clock framework will not be able to deal with that mux
> being already set by the bootloader, and if we need to support that
> clock in the future, our binding will be ready for it.

I wish I knew which clock they're talking about..

User manuals (A10/A20) only specify following in the clock register
description:

BIT(24) - CLK_SRC_GATING, default 0x0
Clock Source Select:
0: PLL6 for SATA(100MHz)
1: External Clock

There's no section for SATA (called NC) in A10 manual, and in A20
manual only contains list of SATA/AHCI features.


> 
> > +static CLK_FIXED_FACTOR(pll_periph_2x_clk, "pll-periph-2x",
> > > > +			"pll-periph", 1, 2, CLK_SET_RATE_PARENT);
> > +/* We hardcode the divider to 4 for now */
> > +static CLK_FIXED_FACTOR(pll_audio_clk, "pll-audio",
> > > > +			"pll-audio-base", 4, 1, CLK_SET_RATE_PARENT);
> > +static CLK_FIXED_FACTOR(pll_audio_2x_clk, "pll-audio-2x",
> > > > +			"pll-audio-base", 2, 1, CLK_SET_RATE_PARENT);
> > +static CLK_FIXED_FACTOR(pll_audio_4x_clk, "pll-audio-4x",
> > > > +			"pll-audio-base", 1, 1, CLK_SET_RATE_PARENT);
> > +static CLK_FIXED_FACTOR(pll_audio_8x_clk, "pll-audio-8x",
> > > > +			"pll-audio-base", 1, 2, CLK_SET_RATE_PARENT);
> > +static CLK_FIXED_FACTOR(pll_video0_2x_clk, "pll-video0-2x",
> > > > +			"pll-video0", 1, 2, CLK_SET_RATE_PARENT);
> > +static CLK_FIXED_FACTOR(pll_video1_2x_clk, "pll-video1-2x",
> > +			"pll-video1", 1, 2, CLK_SET_RATE_PARENT);
> 
> It feels more natural to just have the clocks defined in the same
> order than their parents. So periph shouldn't be first

Ok, will move the periph clock after the video.

> > +static struct ccu_reset_map sun7i_a20_ccu_resets[] = {
> > +
> > > > > > +	[RST_USB_PHY0]		= { 0x0cc, BIT(0) },
> > > > > > +	[RST_USB_PHY1]		= { 0x0cc, BIT(1) },
> > > > > > +	[RST_USB_PHY2]		= { 0x0cc, BIT(2) },
> > > > > > +	[RST_DE_BE0]		= { 0x104, BIT(30) },
> > > > > > +	[RST_DE_BE1]		= { 0x108, BIT(30) },
> > > > > > +	[RST_DE_FE0]		= { 0x10c, BIT(30) },
> > > > > > +	[RST_DE_FE1]		= { 0x110, BIT(30) },
> > > > > > +	[RST_DE_MP]		= { 0x114, BIT(30) },
> > > > > > +	[RST_TCON0]		= { 0x118, BIT(30) },
> > > > > > +	[RST_TCON1]		= { 0x11c, BIT(30) },
> > > > > > +	[RST_CSI0]		= { 0x134, BIT(30) },
> > > > > > +	[RST_CSI1]		= { 0x138, BIT(30) },
> > > > > > +	[RST_VE]		= { 0x13c, BIT(0) },
> > > > > > +	[RST_ACE]		= { 0x148, BIT(16) },
> > > > > > +	[RST_LVDS]		= { 0x14c, BIT(0) },
> > > > > > +	[RST_GPU]		= { 0x154, BIT(30) },
> > > > > > +	[RST_HDMI_H]		= { 0x170, BIT(0) },
> > > > > > +	[RST_HDMI_SYS]		= { 0x170, BIT(1) },
> > > > > > +	[RST_HDMI_AUDIO_DMA]	= { 0x170, BIT(2) },
> > +};
> > +
> > +static const struct sunxi_ccu_desc sun7i_a20_ccu_desc = {
> > > > > > +	.ccu_clks	= sun7i_a20_ccu_clks,
> > > > > > +	.num_ccu_clks	= ARRAY_SIZE(sun7i_a20_ccu_clks),
> > +
> > > > > > +	.hw_clks	= &sun7i_a20_hw_clks,
> > +
> > > > > > +	.resets		= sun7i_a20_ccu_resets,
> > > > > > +	.num_resets	= ARRAY_SIZE(sun7i_a20_ccu_resets),
> > +};
> > +
> > +static void __init sun7i_a20_ccu_setup(struct device_node *node)
> > +{
> > > > +	void __iomem *reg;
> > > > +	u32 val;
> > +
> > > > +	reg = of_io_request_and_map(node, 0, of_node_full_name(node));
> > > > +	if (IS_ERR(reg)) {
> > > > +		pr_err("%s: Could not map the clock registers\n",
> > > > +		       of_node_full_name(node));
> > > > +		return;
> > > > +	}
> > +
> > +	#define SUN7I_PLL_AUDIO_REG	0x008
> 
> This should be defined above

Will do..
> 
> > +
> > > > +	/* Force the PLL-Audio-1x divider to 4 */
> > > > +	val = readl(reg + SUN7I_PLL_AUDIO_REG);
> > > > +	val &= ~GENMASK(19, 16);
> > > > +	writel(val | (3 << 16), reg + SUN7I_PLL_AUDIO_REG);
> > +
> > > > +	/*
> > > > +	 * Use PLL6 as parent for AHB
> > +	 * CPU/AXI clock changes rate when cpufreq is enabled
> 
> I'm not sure why that last sentence is needed too. A lot of clock
> listed there change rate when <some-feature> is enabled.

Will remove.

> 
> > +/* Some AHB gates are exported */
> > > > +#define CLK_AHB_BIST		31
> > > > +#define CLK_AHB_MS		36
> > > > +#define CLK_AHB_SDRAM		38
> > > > +#define CLK_AHB_ACE		39
> > > > +#define CLK_AHB_TS		41
> > > > +#define CLK_AHB_VE		48
> > > > +#define CLK_AHB_TVD		49
> > > > +#define CLK_AHB_TVE1		51
> > > > +#define CLK_AHB_LCD1		53
> > > > +#define CLK_AHB_CSI0		54
> > > > +#define CLK_AHB_CSI1		55
> > > > +#define CLK_AHB_HDMI0		56
> > > > +#define CLK_AHB_DE_BE1		59
> > > > +#define CLK_AHB_DE_FE0		60
> > > > +#define CLK_AHB_DE_FE1		61
> > > > +#define CLK_AHB_MP		63
> > > > +#define CLK_AHB_GPU		64
> > +
> > +/* Some APB0 gates are exported */
> > > > +#define CLK_APB0_AC97		67
> > > > +#define CLK_APB0_KEYPAD		74
> > +
> > +/* Some APB1 gates are exported */
> > > > +#define CLK_APB1_CAN		79
> > > > +#define CLK_APB1_SCR		80
> > +
> > +/* Some IP module clocks are exported */
> > > > +#define CLK_MS			93
> > > > +#define CLK_TS			106
> > > > +#define CLK_PATA		111
> > > > +#define CLK_AC97		115
> > > > +#define CLK_KEYPAD		117
> > > > +#define CLK_SATA		118
> > +
> > +/* Some DRAM gates are exported */
> > > > +#define CLK_DRAM_VE		125
> > > > +#define CLK_DRAM_CSI0		126
> > > > +#define CLK_DRAM_CSI1		127
> > > > +#define CLK_DRAM_TS		128
> > > > +#define CLK_DRAM_TVD		129
> > > > +#define CLK_DRAM_TVE1		131
> > > > +#define CLK_DRAM_OUT		132
> > > > +#define CLK_DRAM_DE_FE1		133
> > > > +#define CLK_DRAM_DE_FE0		134
> > > > +#define CLK_DRAM_DE_BE1		136
> > > > +#define CLK_DRAM_MP		137
> > > > +#define CLK_DRAM_ACE		138
> > +
> > > > +#define CLK_DE_BE1		140
> > > > +#define CLK_DE_FE0		141
> > > > +#define CLK_DE_FE1		142
> > > > +#define CLK_DE_MP		143
> > > > +#define CLK_TCON1_CH0		145
> > > > +#define CLK_CSI_SPECIAL		146
> > > > +#define CLK_TVD			147
> > > > +#define CLK_TCON0_CH1_SCLK2	148
> > > > +#define CLK_TCON1_CH1_SCLK2	150
> > > > +#define CLK_TCON1_CH1		151
> > > > +#define CLK_CSI0		152
> > > > +#define CLK_CSI1		153
> > > > +#define CLK_VE			154
> > > > +#define CLK_AVS			156
> > > > +#define CLK_ACE			157
> > > > +#define CLK_HDMI		158
> > > > +#define CLK_GPU			159
> > > > +#define CLK_MBUS		160
> > > > +#define CLK_HDMI1_SLOW		161
> > > > +#define CLK_HDMI1_REPEAT	162
> > > > +#define CLK_OUT_A		163
> > +#define CLK_OUT_B		164
> 
> Is there a reason not to expose these clocks?

I exposed them on need to have basis. And basically did one-to-one
conversion from devicetree.

Päikest,
Priit

[toc] | [next] | [standalone]


#1591136

FromMaxime Ripard <maxime.ripard@free-electrons.com>
Date2017-03-02 15:30 +0100
Message-ID<tgzTZ-3s2-31@gated-at.bofh.it>
In reply to#1590657

[Multipart message — attachments visible in raw view] — view raw

Hi Priit,

On Wed, Mar 01, 2017 at 11:38:14PM +0200, Priit Laes wrote:
> > > +/* PLL2 - Audio clock */
> > > +static struct ccu_nm pll_audio_base_clk = {
> > > > > > > +	.enable		= BIT(31),
> > > > > > > +	.n		= _SUNXI_CCU_MULT_OFFSET(8, 7, 0),
> > > > > > > +	.m		= _SUNXI_CCU_DIV_OFFSET(0, 5, 0),
> > > > > > > +	.common		= {
> > > > > > > +		.reg		= 0x008,
> > > > > > > +		.hw.init	= CLK_HW_INIT("pll-audio-base",
> > > > > +					      "hosc",
> > > > > +					      &ccu_nm_ops,
> > > > > +					      0),
> > > > > +	},
> > > +
> > > +};
> > 
> > You're forgetting the post-divider here
> 
> It's hardcoded to 4 during ccu initialization, similar to what is done
> on the other SoCs (A13, A31..).

Right, sorry, I only saw it later. Please move that define you've been
using here, and it will be fine :)

> > > +/* TODO: pll8 gpu 0x040 */
> > 
> > Please add all the clocks.
> 
> I'm not really comfortable adding clocks for blocks that currently lack
> drivers.

Yet, you did it for quite a significant amount already (VE, NAND,
AC97, DE MP, etc.). Don't get me wrong, this is definitely not a
criticism. One of the point of the switch to sunxi-ng was that we
would get out of the previous situation where every time you wanted to
do something, you needed to add some clocks.

We have some generic code that, if fed the right data, will
(hopefully) just work. So it's pretty safe to add (and this is better
to be consistent, and that's the policy we had for all the other CCU
drivers).

> > > +/* BIT(21 .. 31) - reserved */
> > 
> > I'm not sure we need those comments either.
> > 
> > > +/*
> > > + * TODO: SATA clock also supports external clock as parent.
> > > + * Currently we default to using PLL6 SATA gate.
> > > + */
> > 
> > Which external clock? It should be modelled anyway. If we have a
> > dependency on some other clock, it should be in our DT binding, and
> > listed in the mux there.
> > 
> > Otherwise, the clock framework will not be able to deal with that mux
> > being already set by the bootloader, and if we need to support that
> > clock in the future, our binding will be ready for it.
> 
> I wish I knew which clock they're talking about..
> 
> User manuals (A10/A20) only specify following in the clock register
> description:
> 
> BIT(24) - CLK_SRC_GATING, default 0x0
> Clock Source Select:
> 0: PLL6 for SATA(100MHz)
> 1: External Clock
> 
> There's no section for SATA (called NC) in A10 manual, and in A20
> manual only contains list of SATA/AHCI features.

Hmmmm, ok :/

> > > +/* Some AHB gates are exported */
> > > > > +#define CLK_AHB_BIST		31
> > > > > +#define CLK_AHB_MS		36
> > > > > +#define CLK_AHB_SDRAM		38
> > > > > +#define CLK_AHB_ACE		39
> > > > > +#define CLK_AHB_TS		41
> > > > > +#define CLK_AHB_VE		48
> > > > > +#define CLK_AHB_TVD		49
> > > > > +#define CLK_AHB_TVE1		51
> > > > > +#define CLK_AHB_LCD1		53
> > > > > +#define CLK_AHB_CSI0		54
> > > > > +#define CLK_AHB_CSI1		55
> > > > > +#define CLK_AHB_HDMI0		56
> > > > > +#define CLK_AHB_DE_BE1		59
> > > > > +#define CLK_AHB_DE_FE0		60
> > > > > +#define CLK_AHB_DE_FE1		61
> > > > > +#define CLK_AHB_MP		63
> > > > > +#define CLK_AHB_GPU		64
> > > +
> > > +/* Some APB0 gates are exported */
> > > > > +#define CLK_APB0_AC97		67
> > > > > +#define CLK_APB0_KEYPAD		74
> > > +
> > > +/* Some APB1 gates are exported */
> > > > > +#define CLK_APB1_CAN		79
> > > > > +#define CLK_APB1_SCR		80
> > > +
> > > +/* Some IP module clocks are exported */
> > > > > +#define CLK_MS			93
> > > > > +#define CLK_TS			106
> > > > > +#define CLK_PATA		111
> > > > > +#define CLK_AC97		115
> > > > > +#define CLK_KEYPAD		117
> > > > > +#define CLK_SATA		118
> > > +
> > > +/* Some DRAM gates are exported */
> > > > > +#define CLK_DRAM_VE		125
> > > > > +#define CLK_DRAM_CSI0		126
> > > > > +#define CLK_DRAM_CSI1		127
> > > > > +#define CLK_DRAM_TS		128
> > > > > +#define CLK_DRAM_TVD		129
> > > > > +#define CLK_DRAM_TVE1		131
> > > > > +#define CLK_DRAM_OUT		132
> > > > > +#define CLK_DRAM_DE_FE1		133
> > > > > +#define CLK_DRAM_DE_FE0		134
> > > > > +#define CLK_DRAM_DE_BE1		136
> > > > > +#define CLK_DRAM_MP		137
> > > > > +#define CLK_DRAM_ACE		138
> > > +
> > > > > +#define CLK_DE_BE1		140
> > > > > +#define CLK_DE_FE0		141
> > > > > +#define CLK_DE_FE1		142
> > > > > +#define CLK_DE_MP		143
> > > > > +#define CLK_TCON1_CH0		145
> > > > > +#define CLK_CSI_SPECIAL		146
> > > > > +#define CLK_TVD			147
> > > > > +#define CLK_TCON0_CH1_SCLK2	148
> > > > > +#define CLK_TCON1_CH1_SCLK2	150
> > > > > +#define CLK_TCON1_CH1		151
> > > > > +#define CLK_CSI0		152
> > > > > +#define CLK_CSI1		153
> > > > > +#define CLK_VE			154
> > > > > +#define CLK_AVS			156
> > > > > +#define CLK_ACE			157
> > > > > +#define CLK_HDMI		158
> > > > > +#define CLK_GPU			159
> > > > > +#define CLK_MBUS		160
> > > > > +#define CLK_HDMI1_SLOW		161
> > > > > +#define CLK_HDMI1_REPEAT	162
> > > > > +#define CLK_OUT_A		163
> > > +#define CLK_OUT_B		164
> > 
> > Is there a reason not to expose these clocks?
> 
> I exposed them on need to have basis. And basically did one-to-one
> conversion from devicetree.

I guess we can still make some pretty good assumptions on what's going
to be needed at some point.

All the mod clocks will be, the bus gates too, the CPU too. All the
internal ones (PLL, AXI, APB, etc) can remain hidden though.

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

[toc] | [prev] | [next] | [standalone]


#1591200 — Re: [linux-sunxi] Re: [PATCH 2/4] clk: sunxi-ng: Add sun7i-a20 CCU driver

FromChen-Yu Tsai <wens@csie.org>
Date2017-03-02 16:40 +0100
SubjectRe: [linux-sunxi] Re: [PATCH 2/4] clk: sunxi-ng: Add sun7i-a20 CCU driver
Message-ID<tgAZI-4mT-21@gated-at.bofh.it>
In reply to#1591136
On Thu, Mar 2, 2017 at 10:21 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> Hi Priit,
>
> On Wed, Mar 01, 2017 at 11:38:14PM +0200, Priit Laes wrote:
>> > > +/* PLL2 - Audio clock */
>> > > +static struct ccu_nm pll_audio_base_clk = {
>> > > > > > > + .enable         = BIT(31),
>> > > > > > > + .n              = _SUNXI_CCU_MULT_OFFSET(8, 7, 0),
>> > > > > > > + .m              = _SUNXI_CCU_DIV_OFFSET(0, 5, 0),
>> > > > > > > + .common         = {
>> > > > > > > +         .reg            = 0x008,
>> > > > > > > +         .hw.init        = CLK_HW_INIT("pll-audio-base",
>> > > > > +                                           "hosc",
>> > > > > +                                           &ccu_nm_ops,
>> > > > > +                                           0),
>> > > > > +     },
>> > > +
>> > > +};
>> >
>> > You're forgetting the post-divider here
>>
>> It's hardcoded to 4 during ccu initialization, similar to what is done
>> on the other SoCs (A13, A31..).
>
> Right, sorry, I only saw it later. Please move that define you've been
> using here, and it will be fine :)
>
>> > > +/* TODO: pll8 gpu 0x040 */
>> >
>> > Please add all the clocks.
>>
>> I'm not really comfortable adding clocks for blocks that currently lack
>> drivers.
>
> Yet, you did it for quite a significant amount already (VE, NAND,
> AC97, DE MP, etc.). Don't get me wrong, this is definitely not a
> criticism. One of the point of the switch to sunxi-ng was that we
> would get out of the previous situation where every time you wanted to
> do something, you needed to add some clocks.
>
> We have some generic code that, if fed the right data, will
> (hopefully) just work. So it's pretty safe to add (and this is better
> to be consistent, and that's the policy we had for all the other CCU
> drivers).
>
>> > > +/* BIT(21 .. 31) - reserved */
>> >
>> > I'm not sure we need those comments either.
>> >
>> > > +/*
>> > > + * TODO: SATA clock also supports external clock as parent.
>> > > + * Currently we default to using PLL6 SATA gate.
>> > > + */
>> >
>> > Which external clock? It should be modelled anyway. If we have a
>> > dependency on some other clock, it should be in our DT binding, and
>> > listed in the mux there.
>> >
>> > Otherwise, the clock framework will not be able to deal with that mux
>> > being already set by the bootloader, and if we need to support that
>> > clock in the future, our binding will be ready for it.
>>
>> I wish I knew which clock they're talking about..
>>
>> User manuals (A10/A20) only specify following in the clock register
>> description:
>>
>> BIT(24) - CLK_SRC_GATING, default 0x0
>> Clock Source Select:
>> 0: PLL6 for SATA(100MHz)
>> 1: External Clock
>>
>> There's no section for SATA (called NC) in A10 manual, and in A20
>> manual only contains list of SATA/AHCI features.
>
> Hmmmm, ok :/

The external clock is probably an optional crystal or oscillator
that can be connected to the SATA-CLKM / SATA-CLKP pins.

The datasheet does not say what the frequency or any other parameters
should be though. And to my knowledge no board uses it.

ChenYu

>> > > +/* Some AHB gates are exported */
>> > > > > +#define CLK_AHB_BIST         31
>> > > > > +#define CLK_AHB_MS           36
>> > > > > +#define CLK_AHB_SDRAM                38
>> > > > > +#define CLK_AHB_ACE          39
>> > > > > +#define CLK_AHB_TS           41
>> > > > > +#define CLK_AHB_VE           48
>> > > > > +#define CLK_AHB_TVD          49
>> > > > > +#define CLK_AHB_TVE1         51
>> > > > > +#define CLK_AHB_LCD1         53
>> > > > > +#define CLK_AHB_CSI0         54
>> > > > > +#define CLK_AHB_CSI1         55
>> > > > > +#define CLK_AHB_HDMI0                56
>> > > > > +#define CLK_AHB_DE_BE1               59
>> > > > > +#define CLK_AHB_DE_FE0               60
>> > > > > +#define CLK_AHB_DE_FE1               61
>> > > > > +#define CLK_AHB_MP           63
>> > > > > +#define CLK_AHB_GPU          64
>> > > +
>> > > +/* Some APB0 gates are exported */
>> > > > > +#define CLK_APB0_AC97                67
>> > > > > +#define CLK_APB0_KEYPAD              74
>> > > +
>> > > +/* Some APB1 gates are exported */
>> > > > > +#define CLK_APB1_CAN         79
>> > > > > +#define CLK_APB1_SCR         80
>> > > +
>> > > +/* Some IP module clocks are exported */
>> > > > > +#define CLK_MS                       93
>> > > > > +#define CLK_TS                       106
>> > > > > +#define CLK_PATA             111
>> > > > > +#define CLK_AC97             115
>> > > > > +#define CLK_KEYPAD           117
>> > > > > +#define CLK_SATA             118
>> > > +
>> > > +/* Some DRAM gates are exported */
>> > > > > +#define CLK_DRAM_VE          125
>> > > > > +#define CLK_DRAM_CSI0                126
>> > > > > +#define CLK_DRAM_CSI1                127
>> > > > > +#define CLK_DRAM_TS          128
>> > > > > +#define CLK_DRAM_TVD         129
>> > > > > +#define CLK_DRAM_TVE1                131
>> > > > > +#define CLK_DRAM_OUT         132
>> > > > > +#define CLK_DRAM_DE_FE1              133
>> > > > > +#define CLK_DRAM_DE_FE0              134
>> > > > > +#define CLK_DRAM_DE_BE1              136
>> > > > > +#define CLK_DRAM_MP          137
>> > > > > +#define CLK_DRAM_ACE         138
>> > > +
>> > > > > +#define CLK_DE_BE1           140
>> > > > > +#define CLK_DE_FE0           141
>> > > > > +#define CLK_DE_FE1           142
>> > > > > +#define CLK_DE_MP            143
>> > > > > +#define CLK_TCON1_CH0                145
>> > > > > +#define CLK_CSI_SPECIAL              146
>> > > > > +#define CLK_TVD                      147
>> > > > > +#define CLK_TCON0_CH1_SCLK2  148
>> > > > > +#define CLK_TCON1_CH1_SCLK2  150
>> > > > > +#define CLK_TCON1_CH1                151
>> > > > > +#define CLK_CSI0             152
>> > > > > +#define CLK_CSI1             153
>> > > > > +#define CLK_VE                       154
>> > > > > +#define CLK_AVS                      156
>> > > > > +#define CLK_ACE                      157
>> > > > > +#define CLK_HDMI             158
>> > > > > +#define CLK_GPU                      159
>> > > > > +#define CLK_MBUS             160
>> > > > > +#define CLK_HDMI1_SLOW               161
>> > > > > +#define CLK_HDMI1_REPEAT     162
>> > > > > +#define CLK_OUT_A            163
>> > > +#define CLK_OUT_B                164
>> >
>> > Is there a reason not to expose these clocks?
>>
>> I exposed them on need to have basis. And basically did one-to-one
>> conversion from devicetree.
>
> I guess we can still make some pretty good assumptions on what's going
> to be needed at some point.
>
> All the mod clocks will be, the bus gates too, the CPU too. All the
> internal ones (PLL, AXI, APB, etc) can remain hidden though.
>
> Thanks!
> Maxime
>
> --
> Maxime Ripard, Free Electrons
> Embedded Linux and Kernel engineering
> http://free-electrons.com

[toc] | [prev] | [standalone]


Back to top | Article view | linux.kernel


csiph-web