Re: [PATCH 1/5] clk: hi3519: add CRG driver for hisilicon hi3519 soc

[xuejiancheng <xuejiancheng@huawei.com>]

Hello Rob,

Thanks for your suggestions!

On 2015/12/1 4:35, Rob Herring wrote:
> On Sat, Nov 28, 2015 at 03:13:26PM +0800, Jiancheng Xue wrote:
>> The CRG(Clock and Reset Generator) module provides
>> clock and reset signals for other modules in hi3519 soc.
>>
>> Signed-off-by: Jiancheng Xue <xuejiancheng@huawei.com>
>> ---
>>  .../devicetree/bindings/clock/hi3519-clock.txt     |  46 +++++++
>>  drivers/clk/hisilicon/Makefile                     |   1 +
>>  drivers/clk/hisilicon/clk-hi3519.c                 | 130 ++++++++++++++++++
>>  drivers/clk/hisilicon/reset.c                      | 149 +++++++++++++++++++++
>>  drivers/clk/hisilicon/reset.h                      |  25 ++++
>>  include/dt-bindings/clock/hi3519-clock.h           |  78 +++++++++++
> 
> It is preferred to put binding doc and header in separate patch.

I will put them in separate patch in next version. Thank you!

> 
>>  6 files changed, 429 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/clock/hi3519-clock.txt
>>  create mode 100644 drivers/clk/hisilicon/clk-hi3519.c
>>  create mode 100644 drivers/clk/hisilicon/reset.c
>>  create mode 100644 drivers/clk/hisilicon/reset.h
>>  create mode 100644 include/dt-bindings/clock/hi3519-clock.h
>>
>> diff --git a/Documentation/devicetree/bindings/clock/hi3519-clock.txt b/Documentation/devicetree/bindings/clock/hi3519-clock.txt
>> new file mode 100644
>> index 0000000..9fea878
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/clock/hi3519-clock.txt
>> @@ -0,0 +1,46 @@
>> +* Hisilicon Hi3519 Clock and Reset Generator(CRG)
>> +
>> +The Hi3519 CRG module provides clock and reset signals to various
>> +controllers within the SoC.
>> +
>> +This binding uses the following bindings:
>> +    Documentation/devicetree/bindings/clock/clock-bindings.txt
>> +    Documentation/devicetree/bindings/reset/reset.txt
>> +
>> +Required Properties:
>> +
>> +- compatible: should be one of the following.
>> +  - "hisilicon,hi3519-clock" - controller compatible with Hi3519 SoC.
> 
> Use -crg rather than -clock if that is the block name.

I agreed with you! It is proper to use -crg.

> 
>> +
>> +- reg: physical base address of the controller and length of memory mapped
>> +  region.
>> +
>> +- #clock-cells: should be 1.
>> +
>> +Each clock is assigned an identifier and client nodes use this identifier
>> +to specify the clock which they consume.
>> +
>> +All these identifier could be found in <dt-bindings/clock/hi3519-clock.h>.
>> +
>> +- #reset-cells: should be 2.
>> +
>> +A reset signal can be controlled by writing a bit register in the CRG module.
>> +The reset specifier consists of two cells. The first cell represents the
>> +register offset relative to the base address. The second cell represents the
>> +bit index in the register.
>> +
>> +Example: CRG nodes
>> +CRG: clock-reset-controller {
>> +	compatible = "hisilicon,hi3519-clock";
>> +        reg = <0x12010000 0x10000>;
>> +        #clock-cells = <1>;
>> +        #reset-cells = <2>;
>> +};
>> +
>> +Example: consumer nodes
>> +i2c0: i2c@0x12110000 {
>> +	compatible = "hisilicon,hi3519-i2c";
>> +        reg = <0x12110000 0x1000>;
>> +        clocks = <&CRG HI3519_I2C0_RST>;*/
>> +        resets = <&CRG 0xE4 0>;
>> +};
> 
> 
>> diff --git a/drivers/clk/hisilicon/reset.h b/drivers/clk/hisilicon/reset.h
>> new file mode 100644
>> index 0000000..74bea4e
>> --- /dev/null
>> +++ b/drivers/clk/hisilicon/reset.h
>> @@ -0,0 +1,25 @@
>> +/*
>> + * Copyright (c) 2015 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 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.
>> + *
>> + * You should have received a copy of the GNU General Public License
>> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
>> + */
>> +
>> +#ifndef	__HISI_RESET_H
>> +#define	__HISI_RESET_H
>> +
>> +#include <linux/of.h>
>> +
>> +int __init hisi_reset_init(struct device_node *np, int nr_rsts);
>> +
>> +#endif	/* __HISI_RESET_H */
>> diff --git a/include/dt-bindings/clock/hi3519-clock.h b/include/dt-bindings/clock/hi3519-clock.h
>> new file mode 100644
>> index 0000000..2e08666
>> --- /dev/null
>> +++ b/include/dt-bindings/clock/hi3519-clock.h
>> @@ -0,0 +1,78 @@
>> +/*
>> + * Copyright (c) 2015 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 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.
>> + *
>> + * You should have received a copy of the GNU General Public License
>> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
>> + */
>> +
>> +#ifndef __DTS_HI3519_CLOCK_H
>> +#define __DTS_HI3519_CLOCK_H
>> +
>> +/* fixed rate */
>> +#define HI3519_FIXED_2376M		1
>> +#define HI3519_FIXED_1188M		2
>> +#define HI3519_FIXED_594M		3
>> +#define HI3519_FIXED_297M		4
>> +#define HI3519_FIXED_148P5M		5
>> +#define HI3519_FIXED_74P25M		6
>> +#define HI3519_FIXED_792M		7
>> +#define HI3519_FIXED_475M		8
>> +#define HI3519_FIXED_340M		9
>> +#define HI3519_FIXED_72M		10
>> +#define HI3519_FIXED_400M		11
>> +#define HI3519_FIXED_200M		12
>> +#define HI3519_FIXED_54M		13
>> +#define HI3519_FIXED_27M		14
>> +#define HI3519_FIXED_37P125M		15
>> +#define HI3519_FIXED_3000M		16
>> +#define HI3519_FIXED_1500M		17
>> +#define HI3519_FIXED_500M		18
>> +#define HI3519_FIXED_250M		19
>> +#define HI3519_FIXED_125M		20
>> +#define HI3519_FIXED_1000M		21
>> +#define HI3519_FIXED_600M		22
>> +#define HI3519_FIXED_750M		23
>> +#define HI3519_FIXED_150M		24
>> +#define HI3519_FIXED_75M		25
>> +#define HI3519_FIXED_300M		26
>> +#define HI3519_FIXED_60M		27
>> +#define HI3519_FIXED_214M		28
>> +#define HI3519_FIXED_107M		29
>> +#define HI3519_FIXED_100M		30
>> +#define HI3519_FIXED_50M		31
>> +#define HI3519_FIXED_25M		32
>> +#define HI3519_FIXED_24M		33
>> +#define HI3519_FIXED_3M			34
> 
> All these are really fixed frequency, not just fixed until the s/w 
> support is written? 

Yes, these clocks are fixed frequency in h/w.

> 
> You only need to include clocks which are externally accessible from the 
> CRG.
> 

Some clocks will be used when other device nodes are added into device trees.
OK. I will delete unused clocks in next version.
And a clocks will be added only when it's needed.


Thank you!

Best Regards,

Jiancheng Xue