Re: [PATCH v6 1/8] clk: rockchip: add new clock-type for the ddrclk

From: Heiko Stuebner <heiko@sntech.de>
To: Lin Huang <hl@rock-chips.com>
Cc: myungjoo.ham@samsung.com, tixy@linaro.org, mark.rutland@arm.com,
	typ@rock-chips.com, linux-rockchip@lists.infradead.org,
	airlied@linux.ie, mturquette@baylibre.com,
	dbasehore@chromium.org, sboyd@codeaurora.org,
	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
	dianders@chromium.org, cw00.choi@samsung.com,
	kyungmin.park@samsung.com, sudeep.holla@arm.com,
	linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	mark.yao@rock-chips.com
Subject: Re: [PATCH v6 1/8] clk: rockchip: add new clock-type for the ddrclk
Date: Fri, 19 Aug 2016 13:33:35 +0200	[thread overview]
Message-ID: <3728841.DF2sM403rc@phil> (raw)
In-Reply-To: <1471386989-9541-2-git-send-email-hl@rock-chips.com>

Hi Lin,

Am Mittwoch, 17. August 2016, 06:36:22 CEST schrieb Lin Huang:
> On new rockchip platform(rk3399 etc), there have dcf controller to
> do ddr frequency scaling, and this controller will implement in
> arm-trust-firmware. We add a special clock-type to handle that.
> 
> Signed-off-by: Lin Huang <hl@rock-chips.com>
> ---
> Changes in v6:
> - none
> 
> Changes in v5:
> - delete unuse mux_flag
> - use div_flag to distinguish sip call and other operate
> 
> Changes in v4:
> - use arm_smccc_smc() to set/read ddr rate
> 
> Changes in v3:
> - use sip call to set/read ddr rate
> 
> Changes in v2:
> - use GENMASK instead val_mask
> - use divider_recalc_rate() instead DIV_ROUND_UP_ULL
> - cleanup code
> 
> Changes in v1:
> - none
> 
>  drivers/clk/rockchip/Makefile       |   1 +
>  drivers/clk/rockchip/clk-ddr.c      | 150
> ++++++++++++++++++++++++++++++++++++ drivers/clk/rockchip/clk.c          | 
>  9 +++
>  drivers/clk/rockchip/clk.h          |  33 ++++++++
>  include/soc/rockchip/rockchip_sip.h |  27 +++++++
>  5 files changed, 220 insertions(+)
>  create mode 100644 drivers/clk/rockchip/clk-ddr.c
>  create mode 100644 include/soc/rockchip/rockchip_sip.h
> 
> diff --git a/drivers/clk/rockchip/Makefile b/drivers/clk/rockchip/Makefile
> index f47a2fa..b5f2c8e 100644
> --- a/drivers/clk/rockchip/Makefile
> +++ b/drivers/clk/rockchip/Makefile
> @@ -8,6 +8,7 @@ obj-y	+= clk-pll.o
>  obj-y	+= clk-cpu.o
>  obj-y	+= clk-inverter.o
>  obj-y	+= clk-mmc-phase.o
> +obj-y	+= clk-ddr.o
>  obj-$(CONFIG_RESET_CONTROLLER)	+= softrst.o
> 
>  obj-y	+= clk-rk3036.o
> diff --git a/drivers/clk/rockchip/clk-ddr.c b/drivers/clk/rockchip/clk-ddr.c
> new file mode 100644
> index 0000000..7dbe8bff
> --- /dev/null
> +++ b/drivers/clk/rockchip/clk-ddr.c
> @@ -0,0 +1,150 @@
> +/*
> + * Copyright (c) 2016 Rockchip Electronics Co. Ltd.
> + * Author: Lin Huang <hl@rock-chips.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * 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/arm-smccc.h>
> +#include <linux/clk.h>
> +#include <linux/clk-provider.h>
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/slab.h>
> +#include <soc/rockchip/rockchip_sip.h>
> +
> +#include "clk.h"
> +
> +struct rockchip_ddrclk {
> +	struct clk_hw	hw;
> +	void __iomem	*reg_base;
> +	int		mux_offset;
> +	int		mux_shift;
> +	int		mux_width;
> +	int		div_shift;
> +	int		div_width;
> +	int		ddr_flag;
> +	spinlock_t	*lock;
> +};
> +
> +#define to_rockchip_ddrclk_hw(hw) container_of(hw, struct rockchip_ddrclk,
> hw) +
> +static int rockchip_ddrclk_set_rate(struct clk_hw *hw, unsigned long drate,
> +				    unsigned long prate)
> +{
> +	struct rockchip_ddrclk *ddrclk = to_rockchip_ddrclk_hw(hw);
> +	unsigned long flags;
> +	struct arm_smccc_res res;
> +
> +	spin_lock_irqsave(ddrclk->lock, flags);
> +	if (ddrclk->ddr_flag == ROCKCHIP_DDRCLK_SIP) {
> +		arm_smccc_smc(SIP_DRAM_FREQ, drate, 0, CONFIG_DRAM_SET_RATE,
> +			      0, 0, 0, 0, &res);
> +		return res.a0;
> +	}
> +	spin_unlock_irqrestore(ddrclk->lock, flags);
> +
> +	return 0;
> +}
> +
> +static unsigned long
> +rockchip_ddrclk_recalc_rate(struct clk_hw *hw,
> +			    unsigned long parent_rate)
> +{
> +	struct rockchip_ddrclk *ddrclk = to_rockchip_ddrclk_hw(hw);
> +	struct arm_smccc_res res;
> +
> +	if (ddrclk->ddr_flag == ROCKCHIP_DDRCLK_SIP) {
> +		arm_smccc_smc(SIP_DRAM_FREQ, 0, 0, CONFIG_DRAM_GET_RATE,
> +			      0, 0, 0, 0, &res);
> +		return res.a0;
> +	}
> +
> +	return 0;
> +}
> +
> +static long clk_ddrclk_round_rate(struct clk_hw *hw, unsigned long rate,

missing a Rockchip prefix

can't you also introduce a SIP method that returns the rounded rate - aka the 
ATF telling you which rate will be actually set, so that you can return a real 
round_rate value?

> +				  unsigned long *prate)
> +{
> +	return rate;
> +}
> +
> +static u8 rockchip_ddrclk_get_parent(struct clk_hw *hw)
> +{
> +	struct rockchip_ddrclk *ddrclk = to_rockchip_ddrclk_hw(hw);
> +	int num_parents = clk_hw_get_num_parents(hw);
> +	u32 val;
> +
> +	val = clk_readl(ddrclk->reg_base +
> +			ddrclk->mux_offset) >> ddrclk->mux_shift;
> +	val &= GENMASK(ddrclk->mux_width - 1, 0);
> +
> +	if (val >= num_parents)
> +		return -EINVAL;
> +
> +	return val;
> +}
> +
> +static const struct clk_ops rockchip_ddrclk_ops = {
> +	.recalc_rate = rockchip_ddrclk_recalc_rate,
> +	.set_rate = rockchip_ddrclk_set_rate,
> +	.round_rate = clk_ddrclk_round_rate,
> +	.get_parent = rockchip_ddrclk_get_parent,
> +};

please make method-specific clock ops, like

static const struct clk_ops rockchip_ddrclk_sip_ops = {
	.recalc_rate = rockchip_ddrclk_sip_recalc_rate,
	.set_rate = rockchip_ddrclk_sip_set_rate,
	.round_rate = clk_ddrclk_round_rate,
	.get_parent = rockchip_ddrclk_get_parent,
};

and in rockchip_clk_register_ddrclk simply do

...
switch(ddr_flag) {
case ROCKCHIP_DDRCLK_SIP:
	init.ops = &rockchip_ddrclk_sip_ops;
	break;
default:
	pr_err("%s: unsupported ddrclk type %d\n", __func__, ddr_flag);
	return ERR_PTR("-EINVAL);
}
...

That way you save all the ifs in the functions ... essentially how the plls 
also handle the different types.

> +struct clk *rockchip_clk_register_ddrclk(const char *name, int flags,
> +					 const char *const *parent_names,
> +					 u8 num_parents, int mux_offset,
> +					 int mux_shift, int mux_width,
> +					 int div_shift, int div_width,
> +					 int ddr_flag, void __iomem *reg_base,
> +					 spinlock_t *lock)
> +{
> +	struct rockchip_ddrclk *ddrclk;
> +	struct clk_init_data init;
> +	struct clk *clk;
> +
> +	ddrclk = kzalloc(sizeof(*ddrclk), GFP_KERNEL);
> +	if (!ddrclk)
> +		return ERR_PTR(-ENOMEM);
> +
> +	init.name = name;
> +	init.parent_names = parent_names;
> +	init.num_parents = num_parents;
> +	init.ops = &rockchip_ddrclk_ops;
> +
> +	init.flags = flags;
> +	init.flags |= CLK_SET_RATE_NO_REPARENT;
> +	init.flags |= CLK_GET_RATE_NOCACHE;
> +
> +	ddrclk->reg_base = reg_base;
> +	ddrclk->lock = lock;
> +	ddrclk->hw.init = &init;
> +	ddrclk->mux_offset = mux_offset;
> +	ddrclk->mux_shift = mux_shift;
> +	ddrclk->mux_width = mux_width;
> +	ddrclk->div_shift = div_shift;
> +	ddrclk->div_width = div_width;
> +	ddrclk->ddr_flag = ddr_flag;
> +
> +	clk = clk_register(NULL, &ddrclk->hw);
> +	if (IS_ERR(clk)) {
> +		pr_err("%s: could not register ddrclk %s\n", __func__,	name);
> +		goto free_ddrclk;
> +	}
> +
> +	return clk;
> +
> +free_ddrclk:
> +	kfree(ddrclk);
> +
> +	return NULL;
> +}
> diff --git a/drivers/clk/rockchip/clk.c b/drivers/clk/rockchip/clk.c
> index 1f1c74f..99baa5d 100644
> --- a/drivers/clk/rockchip/clk.c
> +++ b/drivers/clk/rockchip/clk.c
> @@ -484,6 +484,15 @@ void __init rockchip_clk_register_branches(
>  				list->gate_offset, list->gate_shift,
>  				list->gate_flags, flags, &ctx->lock);
>  			break;
> +		case branch_ddrc:
> +			clk = rockchip_clk_register_ddrclk(
> +				list->name, list->flags,
> +				list->parent_names, list->num_parents,
> +				list->muxdiv_offset, list->mux_shift,
> +				list->mux_width, list->div_shift,
> +				list->div_width, list->div_flags,
> +				ctx->reg_base, &ctx->lock);
> +			break;
>  		}
> 
>  		/* none of the cases above matched */
> diff --git a/drivers/clk/rockchip/clk.h b/drivers/clk/rockchip/clk.h
> index 3747de5..62c67f2 100644
> --- a/drivers/clk/rockchip/clk.h
> +++ b/drivers/clk/rockchip/clk.h
> @@ -112,6 +112,12 @@ struct clk;
>  #define RK3399_PMU_CLKGATE_CON(x)	((x) * 0x4 + 0x100)
>  #define RK3399_PMU_SOFTRST_CON(x)	((x) * 0x4 + 0x110)
> 
> +/*
> + * for COMPOSITE_DDRCLK div_flag
> + * it means set use sip call to set ddr clock in bl31
> + */

please shorten that comment a bit, like
/* use SIP call to firmware to change ddrclk rate */

> +#define ROCKCHIP_DDRCLK_SIP		0x01
> +
>  enum rockchip_pll_type {
>  	pll_rk3036,
>  	pll_rk3066,
> @@ -281,6 +287,14 @@ struct clk *rockchip_clk_register_mmc(const char *name,
> const char *const *parent_names, u8 num_parents,
>  				void __iomem *reg, int shift);
> 

and move that constant here please

> +struct clk *rockchip_clk_register_ddrclk(const char *name, int flags,
> +					 const char *const *parent_names,
> +					 u8 num_parents, int mux_offset,
> +					 int mux_shift, int mux_width,
> +					 int div_shift, int div_width,
> +					 int ddr_flags, void __iomem *reg_base,
> +					 spinlock_t *lock);
> +
>  #define ROCKCHIP_INVERTER_HIWORD_MASK	BIT(0)
> 
>  struct clk *rockchip_clk_register_inverter(const char *name,
> @@ -299,6 +313,7 @@ enum rockchip_clk_branch_type {
>  	branch_mmc,
>  	branch_inverter,
>  	branch_factor,
> +	branch_ddrc,
>  };
> 
>  struct rockchip_clk_branch {
> @@ -488,6 +503,24 @@ struct rockchip_clk_branch {
>  		.child		= ch,				\
>  	}
> 
> +#define COMPOSITE_DDRCLK(_id, cname, pnames, f, mo, ms, mw,	\
> +			 ds, dw, df)				\
> +	{							\
> +		.id		= _id,				\
> +		.branch_type	= branch_ddrc,			\
> +		.name		= cname,			\
> +		.parent_names	= pnames,			\
> +		.num_parents	= ARRAY_SIZE(pnames),		\
> +		.flags		= f,				\
> +		.muxdiv_offset  = mo,                           \
> +		.mux_shift      = ms,                           \
> +		.mux_width      = mw,                           \
> +		.div_shift      = ds,                           \
> +		.div_width      = dw,                           \
> +		.div_flags	= df,				\
> +		.gate_offset    = -1,                           \
> +	}
> +
>  #define MUX(_id, cname, pnames, f, o, s, w, mf)			\
>  	{							\
>  		.id		= _id,				\
> diff --git a/include/soc/rockchip/rockchip_sip.h
> b/include/soc/rockchip/rockchip_sip.h new file mode 100644
> index 0000000..422ea36
> --- /dev/null
> +++ b/include/soc/rockchip/rockchip_sip.h
> @@ -0,0 +1,27 @@
> +/*
> + * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
> + * Author: Lin Huang <hl@rock-chips.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope 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.
> + */
> +#ifndef __SOC_ROCKCHIP_SIP_H
> +#define __SOC_ROCKCHIP_SIP_H
> +
> +#define SIP_DRAM_FREQ		0x82000008
> +#define CONFIG_DRAM_INIT	0x00
> +#define CONFIG_DRAM_SET_RATE	0x01
> +#define CONFIG_DRAM_ROUND_RATE	0x02
> +#define CONFIG_DRAM_SET_AT_SR	0x03
> +#define CONFIG_DRAM_GET_BW	0x04
> +#define CONFIG_DRAM_GET_RATE	0x05
> +#define CONFIG_DRAM_CLR_IRQ	0x06
> +#define CONFIG_DRAM_SET_PARAM	0x07

this is a public header, so please give the constants a more specific name 
(ROCKCHIP_SIP_*, ROCKCHIP_SIP_CONFIG_*) so that it doesn't produce collisions 
later on.

Apart from that stuff above, this looks really nice now.

Heiko