Re: [project-aspen-dev] Re: [PATCH 1/3] clk: hisilicon: add hisi phase clock support

[Jiancheng Xue]

Hi Shawn,

On 2017/11/16 10:31, Shawn Guo wrote:
> On Wed, Oct 18, 2017 at 07:00:27AM -0400, Jiancheng Xue wrote:
>> From: tianshuliang <tianshuliang@xxxxxxxxxxxxx>
>>
>> Add a phase clock type for HiSilicon SoCs,which supports
>> clk_set_phase operation.
> 
> As the pair of phase operation, I don't see why clk_get_phase operation
> is missing.
> 
>>
>> Signed-off-by: tianshuliang <tianshuliang@xxxxxxxxxxxxx>
>> Signed-off-by: Jiancheng Xue <xuejiancheng@xxxxxxxxxxxxx>
>> ---
>>  drivers/clk/hisilicon/Makefile         |   2 +-
>>  drivers/clk/hisilicon/clk-hisi-phase.c | 117 +++++++++++++++++++++++++++++++++
>>  drivers/clk/hisilicon/clk.c            |  45 +++++++++++++
>>  drivers/clk/hisilicon/clk.h            |  22 +++++++
>>  4 files changed, 185 insertions(+), 1 deletion(-)
>>  create mode 100644 drivers/clk/hisilicon/clk-hisi-phase.c
>>
>> diff --git a/drivers/clk/hisilicon/Makefile b/drivers/clk/hisilicon/Makefile
>> index 1e4c3dd..7189f07 100644
>> --- a/drivers/clk/hisilicon/Makefile
>> +++ b/drivers/clk/hisilicon/Makefile
>> @@ -2,7 +2,7 @@
>>  # Hisilicon Clock specific Makefile
>>  #
>>  
>> -obj-y	+= clk.o clkgate-separated.o clkdivider-hi6220.o
>> +obj-y	+= clk.o clkgate-separated.o clkdivider-hi6220.o clk-hisi-phase.o
>>  
>>  obj-$(CONFIG_ARCH_HI3xxx)	+= clk-hi3620.o
>>  obj-$(CONFIG_ARCH_HIP04)	+= clk-hip04.o
>> diff --git a/drivers/clk/hisilicon/clk-hisi-phase.c b/drivers/clk/hisilicon/clk-hisi-phase.c
>> new file mode 100644
>> index 0000000..436f0a1
>> --- /dev/null
>> +++ b/drivers/clk/hisilicon/clk-hisi-phase.c
>> @@ -0,0 +1,117 @@
>> +/*
>> + * Copyright (c) 2017 HiSilicon Technologies Co., Ltd.
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + *
>> + * Simple HiSilicon phase clock implementation.
>> + */
>> +#include <linux/err.h>
>> +#include <linux/io.h>
>> +#include <linux/module.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/slab.h>
>> +#include "clk.h"
>> +
>> +struct clk_hisi_phase {
>> +	struct clk_hw	hw;
>> +	void __iomem	*reg;
>> +	u32		*phase_values;
>> +	u32		*phase_regs;
>> +	u8		phase_num;
> 
> I do not think this value-reg table is necessary, as the register value
> maps to phase degree in a way that is easy for programming, i.e. degree
> increases 45 with register value increases one.
> 
We expected that this interface could be more generic. That means it can
be also used in other maps instances.

Regards,
Jiancheng

>> +	u32		mask;
>> +	u8		shift;
>> +	u8		flags;
>> +	spinlock_t	*lock;
>> +};
> 
> Have a newline here.
> 
>> +#define to_clk_hisi_phase(_hw) container_of(_hw, struct clk_hisi_phase, hw)
>> +
>> +static u32 hisi_clk_get_phase_reg(struct clk_hisi_phase *phase, int degrees)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < phase->phase_num; i++)
>> +		if (phase->phase_values[i] == degrees)
>> +			return phase->phase_regs[i];
>> +
>> +	return -EINVAL;
>> +}
>> +
>> +static int hisi_clk_set_phase(struct clk_hw *hw, int degrees)
>> +{
>> +	struct clk_hisi_phase *phase = to_clk_hisi_phase(hw);
>> +	u32 val, phase_reg;
>> +	unsigned long flags = 0;
>> +
>> +	phase_reg = hisi_clk_get_phase_reg(phase, degrees);
>> +	if (phase_reg < 0)
>> +		return phase_reg;
>> +
>> +	if (phase->lock)
>> +		spin_lock_irqsave(phase->lock, flags);
>> +	else
>> +		__acquire(phase->lock);
>> +
>> +	val = clk_readl(phase->reg);
>> +	val &= ~(phase->mask << phase->shift);
>> +	val |= phase_reg << phase->shift;
>> +	clk_writel(val, phase->reg);
>> +
>> +	if (phase->lock)
>> +		spin_unlock_irqrestore(phase->lock, flags);
>> +	else
>> +		__release(phase->lock);
>> +
>> +	return 0;
>> +}
>> +
>> +const struct clk_ops clk_phase_ops = {
>> +	.set_phase = hisi_clk_set_phase,
>> +};
>> +
>> +void clk_unregister_hisi_phase(struct clk *clk)
>> +{
>> +	struct clk_hisi_phase *phase;
>> +	struct clk_hw *hw;
>> +
>> +	hw = __clk_get_hw(clk);
>> +	if (!hw)
>> +		return;
>> +
>> +	phase = to_clk_hisi_phase(hw);
>> +	clk_unregister(clk);
>> +}
>> +EXPORT_SYMBOL_GPL(clk_unregister_hisi_phase);
> 
> If there no reason that this unregister function need to be before
> register function, I would suggest you put it after register function,
> so that you are consistent with other register/unregister function pair
> like hisi_clk_register[unregister]_phase() etc.
> 
> Shawn
> 
>> +
>> +struct clk *clk_register_hisi_phase(struct device *dev,
>> +		const struct hisi_phase_clock *clks,
>> +		void __iomem *base, spinlock_t *lock)
>> +{
>> +	struct clk_hisi_phase *phase;
>> +	struct clk *clk;
>> +	struct clk_init_data init;
>> +
>> +	phase = devm_kzalloc(dev, sizeof(struct clk_hisi_phase), GFP_KERNEL);
>> +	if (!phase)
>> +		return ERR_PTR(-ENOMEM);
>> +
>> +	init.name = clks->name;
>> +	init.ops = &clk_phase_ops;
>> +	init.flags = clks->flags | CLK_IS_BASIC;
>> +	init.parent_names = clks->parent_names ? &clks->parent_names : NULL;
>> +	init.num_parents = clks->parent_names ? 1 : 0;
>> +
>> +	phase->reg = base + clks->offset;
>> +	phase->shift = clks->shift;
>> +	phase->mask = BIT(clks->width) - 1;
>> +	phase->lock = lock;
>> +	phase->phase_values = clks->phase_values;
>> +	phase->phase_regs = clks->phase_regs;
>> +	phase->phase_num = clks->phase_num;
>> +	phase->hw.init = &init;
>> +
>> +	clk = clk_register(NULL, &phase->hw);
>> +	return clk;
>> +}
>> +EXPORT_SYMBOL_GPL(clk_register_hisi_phase);
>> diff --git a/drivers/clk/hisilicon/clk.c b/drivers/clk/hisilicon/clk.c
>> index b73c1df..e3adfad 100644
>> --- a/drivers/clk/hisilicon/clk.c
>> +++ b/drivers/clk/hisilicon/clk.c
>> @@ -197,6 +197,51 @@ int hisi_clk_register_mux(const struct hisi_mux_clock *clks,
>>  }
>>  EXPORT_SYMBOL_GPL(hisi_clk_register_mux);
>>  
>> +int hisi_clk_register_phase(struct device *dev,
>> +			const struct hisi_phase_clock *clks,
>> +			int nums, struct hisi_clock_data *data)
>> +{
>> +	int i;
>> +	struct clk *clk;
>> +	void __iomem *base = data->base;
>> +
>> +	for (i = 0; i < nums; i++) {
>> +		clk =	clk_register_hisi_phase(dev,
>> +				&clks[i], base, &hisi_clk_lock);
>> +
>> +		if (IS_ERR(clk)) {
>> +			pr_err("%s: failed to register clock %s\n",
>> +			       __func__, clks[i].name);
>> +			goto err;
>> +		}
>> +
>> +		data->clk_data.clks[clks[i].id] = clk;
>> +	}
>> +	return 0;
>> +
>> +err:
>> +	while (i--)
>> +		clk_unregister_hisi_phase(data->clk_data.clks[clks[i].id]);
>> +
>> +	return PTR_ERR(clk);
>> +}
>> +EXPORT_SYMBOL_GPL(hisi_clk_register_phase);
>> +
>> +void hisi_clk_unregister_phase(const struct hisi_phase_clock *clks,
>> +				int nums, struct hisi_clock_data *data)
>> +{
>> +	struct clk **clocks = data->clk_data.clks;
>> +	int i, id;
>> +
>> +	for (i = 0; i < nums; i++) {
>> +		id = clks[i].id;
>> +
>> +		if (clocks[id])
>> +			clk_unregister_hisi_phase(clocks[id]);
>> +	}
>> +}
>> +EXPORT_SYMBOL_GPL(hisi_clk_unregister_phase);
>> +
>>  int hisi_clk_register_divider(const struct hisi_divider_clock *clks,
>>  				      int nums, struct hisi_clock_data *data)
>>  {
>> diff --git a/drivers/clk/hisilicon/clk.h b/drivers/clk/hisilicon/clk.h
>> index 4e1d1af..bc18730 100644
>> --- a/drivers/clk/hisilicon/clk.h
>> +++ b/drivers/clk/hisilicon/clk.h
>> @@ -68,6 +68,19 @@ struct hisi_mux_clock {
>>  	const char		*alias;
>>  };
>>  
>> +struct hisi_phase_clock {
>> +	unsigned int    id;
>> +	const char      *name;
>> +	const char      *parent_names;
>> +	unsigned long   flags;
>> +	unsigned long   offset;
>> +	u8		shift;
>> +	u8		width;
>> +	u32		*phase_values;
>> +	u32		*phase_regs;
>> +	u8		phase_num;
>> +};
>> +
>>  struct hisi_divider_clock {
>>  	unsigned int		id;
>>  	const char		*name;
>> @@ -120,6 +133,15 @@ int hisi_clk_register_fixed_factor(const struct hisi_fixed_factor_clock *,
>>  				int, struct hisi_clock_data *);
>>  int hisi_clk_register_mux(const struct hisi_mux_clock *, int,
>>  				struct hisi_clock_data *);
>> +struct clk *clk_register_hisi_phase(struct device *dev,
>> +				const struct hisi_phase_clock *clks,
>> +				void __iomem *base, spinlock_t *lock);
>> +void clk_unregister_hisi_phase(struct clk *clk);
>> +int hisi_clk_register_phase(struct device *dev,
>> +				const struct hisi_phase_clock *clks,
>> +				int nums, struct hisi_clock_data *data);
>> +void hisi_clk_unregister_phase(const struct hisi_phase_clock *clks,
>> +				int nums, struct hisi_clock_data *data);
>>  int hisi_clk_register_divider(const struct hisi_divider_clock *,
>>  				int, struct hisi_clock_data *);
>>  int hisi_clk_register_gate(const struct hisi_gate_clock *,
>> -- 
>> 2.7.4
>>
> 
> .
>