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Date:   Mon, 14 Mar 2022 08:55:44 +0100
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From:   Krzysztof Kozlowski <krzk@kernel.org>
Subject: Re: [PATCH v11 2/2] misc: Add iop driver for Sunplus SP7021
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To:     =?UTF-8?B?VG9ueSBIdWFuZyDpu4Pmh7fljpo=?= <tony.huang@sunplus.com>,
        Tony Huang <tonyhuang.sunplus@gmail.com>,
        "robh+dt@kernel.org" <robh+dt@kernel.org>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "derek.kiernan@xilinx.com" <derek.kiernan@xilinx.com>,
        "dragan.cvetic@xilinx.com" <dragan.cvetic@xilinx.com>,
        "arnd@arndb.de" <arnd@arndb.de>,
        "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
Cc:     =?UTF-8?B?V2VsbHMgTHUg5ZGC6Iqz6aiw?= <wells.lu@sunplus.com>
References: <cover.1647095774.git.tonyhuang.sunplus@gmail.com>
 <07f507a84a9e39d3cd8393f41d1292c250e07642.1647095774.git.tonyhuang.sunplus@gmail.com>
 <00362767-080a-aa7f-672f-22b83ab35e61@kernel.org>
 <42f5f710077b40d7b6fde45789f46732@sphcmbx02.sunplus.com.tw>
In-Reply-To: <42f5f710077b40d7b6fde45789f46732@sphcmbx02.sunplus.com.tw>
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On 14/03/2022 07:08, Tony Huang 黃懷厚 wrote:
> Dear Krzysztof:
> 
>> On 12/03/2022 17:16, Tony Huang wrote:
>>> This driver is load 8051 bin code.
>>> The IOP core is DQ8051, so also named IOP8051.
>>> Need Install DQ8051, The DQ8051 bin file generated by keil C.
>>> We will provide users with 8051 normal and power off source code.
>>> Path: https://sunplus.atlassian.net/wiki/spaces/doc/pages/610172933/
>>>
>> How+to+use+I+O+processor+8051+of+SP7021#5.-Write-C-or-assembly-source-
>>> files-for-IOP
>>> Users can follow the operation steps to generate normal.bin and
>>> poweroff.bin.
>>> Path: https://sunplus.atlassian.net/wiki/spaces/doc/pages/466190338
>>> /26.+IOP8051 26.5?How To Create 8051 bin file
>>>
>>> PMC in power management purpose:
>>> Add sp_iop_poweroff() function. pm_power_off=sp_iop_poweroff.
>>> When the power off command is executed.
>>> The 8051 has a register(DEF_PWR_EN_0=0) to control the power-on and
>>> power-off of the system.
>>>
>>> Signed-off-by: Tony Huang <tonyhuang.sunplus@gmail.com>
>>> ---
>>> Changes in v11:
>>>  - Addressed comments from Arnd Bergmann.
>>
>> How did you address Arnd's comments about splitting the driver to proper
>> parts? drivers/clk and drivers/power/reset?
>>
> 
> drivers/clk : SP7021 system has clock device driver (clk-sp7021.c).		
> So I set the IOP clock through the following function.		
> clk_prepare_enable(iop->iopclk);		
> clk_disable_unprepare(iop->iopclk);		
> 		
> drivers/power/reset : SP7021 system does not have a power off device driver.

What does it mean? The feedback was to split clk and reset features to
separate drivers and I still see only two patches here with a misc
driver. So how is his comments addressed? You did not reply in that thread.

> 
>>>  - Addressed comments from krzysztof.
>>>
>>>  MAINTAINERS                |   1 +
>>>  drivers/misc/Kconfig       |  23 +++
>>>  drivers/misc/Makefile      |   1 +
>>>  drivers/misc/sunplus_iop.c | 411
>>> +++++++++++++++++++++++++++++++++++++++++++++
>>
>> The driver looks like SoC specific driver. Why did you put it in drivers/misc/,
>> not in usual place - drivers/soc/?
> 
> 8051 is designed for processing I/O events, like receiving IR signal from remote controller, 		
> taking care of power on or off requests from RTC, or other hardware events of external peripherals 		
> even when power of main system is off.
> So I put it in drivers/misc.

Is IOP8061 a separate device? Your datasheet is saying its embedded in
SP7021 SoC, so it is a soc driver. This does not fit misc driver
description (a "strange device") but a SoC driver description.

> 
>> sp_iop_poweroff is still here.
> 
> sp_iop_poweroff(): SP7021 system does not have a power off device driver.
> 				I have to put it here.

This should be rather in a reset driver, not in a misc one. What is your
plan for this driver? You described the hardware and judging by it,
there will be quite a lot of separate features so it's reasonable to
split the driver into separate logical elements. However keeping all in
the same place would be ok, if you do not plan to add any more features.
This would mean the driver will handle *only* reset and FW loading.

> 
>>>  4 files changed, 436 insertions(+)
>>>  create mode 100644 drivers/misc/sunplus_iop.c
>>>
>>> diff --git a/MAINTAINERS b/MAINTAINERS index d64c8ed..c282e95 100644
>>> --- a/MAINTAINERS
>>> +++ b/MAINTAINERS
>>> @@ -18246,6 +18246,7 @@ SUNPLUS IOP DRIVER
>>>  M:	Tony Huang <tonyhuang.sunplus@gmail.com>
>>>  S:	Maintained
>>>  F:	Documentation/devicetree/bindings/misc/sunplus,iop.yaml
>>> +F:	drivers/misc/sunplus_iop.c
>>>
>>>  SUPERH
>>>  M:	Yoshinori Sato <ysato@users.sourceforge.jp>
>>> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index
>>> 0f5a49f..e5f32d8 100644
>>> --- a/drivers/misc/Kconfig
>>> +++ b/drivers/misc/Kconfig
>>> @@ -470,6 +470,29 @@ config HISI_HIKEY_USB
>>>  	  switching between the dual-role USB-C port and the USB-A host ports
>>>  	  using only one USB controller.
>>>
>>> +config SUNPLUS_IOP
>>> +	tristate "Sunplus IOP support"
>>> +	default ARCH_SUNPLUS
>>> +	help
>>> +	  This driver is load 8051 bin code.
>>> +	  The IOP core is DQ8051, so also named IOP8051.
>>> +	  Need Install DQ8051, The DQ8051 bin file generated by keil C.
>>> +	  We will provide users with 8051 normal and power off source code.
>>> +	  Path: https://sunplus.atlassian.net/wiki/spaces/doc/pages/610172933/
>>> +
>> How+to+use+I+O+processor+8051+of+SP7021#5.-Write-C-or-assembly-source-
>> files-for-IOP
>>> +	  Users can follow the operation steps to generate normal.bin and
>> poweroff.bin.
>>> +	  Path:
>> https://sunplus.atlassian.net/wiki/spaces/doc/pages/466190338/26.+IOP8051
>>> +	  26.5?How To Create 8051 bin file
>>> +
>>> +	  PMC in power management purpose:
>>> +	  Add sp_iop_poweroff() function. pm_power_off=sp_iop_poweroff.
>>> +	  When the power off command is executed.
>>> +	  The 8051 has a register(DEF_PWR_EN_0=0) to control the power-on
>> and
>>> +	  power-off of the system.
>>> +
>>> +	  This driver can also be built as a module.  If so, the module
>>> +	  will be called sunplus_iop.
>>> +
>>>  source "drivers/misc/c2port/Kconfig"
>>>  source "drivers/misc/eeprom/Kconfig"
>>>  source "drivers/misc/cb710/Kconfig"
>>> diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index
>>> a086197..eafeab6 100644
>>> --- a/drivers/misc/Makefile
>>> +++ b/drivers/misc/Makefile
>>> @@ -52,6 +52,7 @@ obj-$(CONFIG_DW_XDATA_PCIE)	+= dw-xdata-pcie.o
>>>  obj-$(CONFIG_PCI_ENDPOINT_TEST)	+= pci_endpoint_test.o
>>>  obj-$(CONFIG_OCXL)		+= ocxl/
>>>  obj-$(CONFIG_BCM_VK)		+= bcm-vk/
>>> +obj-$(CONFIG_SUNPLUS_IOP)	+= sunplus_iop.o
>>>  obj-y				+= cardreader/
>>>  obj-$(CONFIG_PVPANIC)   	+= pvpanic/
>>>  obj-$(CONFIG_HABANA_AI)		+= habanalabs/
>>> diff --git a/drivers/misc/sunplus_iop.c b/drivers/misc/sunplus_iop.c
>>> new file mode 100644 index 0000000..5bdce5e
>>> --- /dev/null
>>> +++ b/drivers/misc/sunplus_iop.c
>>> @@ -0,0 +1,411 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +/*
>>> + * The IOP driver for Sunplus SP7021
>>> + *
>>> + * Copyright (C) 2021 Sunplus Technology Inc.
>>> + *
>>> + * All Rights Reserved.
>>> + */
>>> +#include <linux/clk.h>
>>> +#include <linux/delay.h>
>>> +#include <linux/dma-mapping.h>
>>> +#include <linux/firmware.h>
>>> +#include <linux/iopoll.h>
>>> +#include <linux/module.h>
>>> +#include <linux/of_platform.h>
>>> +#include <linux/of_address.h>
>>> +#include <linux/of_gpio.h>
>>> +
>>> +/* IOP register offset */
>>> +#define IOP_CONTROL	0x00
>>> +#define IOP_DATA0	0x20
>>> +#define IOP_DATA1	0x24
>>> +#define IOP_DATA2	0x28
>>> +#define IOP_DATA3	0x2c
>>> +#define IOP_DATA4	0x30
>>> +#define IOP_DATA5	0x34
>>> +#define IOP_DATA6	0x38
>>> +#define IOP_DATA7	0x3c
>>> +#define IOP_DATA8	0x40
>>> +#define IOP_DATA9	0x44
>>> +#define IOP_DATA10	0x48
>>> +#define IOP_DATA11	0x4c
>>> +#define IOP_BASE_ADR_L	0x50
>>> +#define IOP_BASE_ADR_H	0x54
>>> +
>>> +/* PMC register offset */
>>> +#define IOP_PMC_TIMER		0x00
>>> +#define IOP_PMC_CTRL		0x04
>>> +#define IOP_XTAL27M_PASSWORD_I	0x08
>>> +#define IOP_XTAL27M_PASSWORD_II	0x0c
>>> +#define IOP_XTAL32K_PASSWORD_I	0x10
>>> +#define IOP_XTAL32K_PASSWORD_II	0x14
>>> +#define IOP_CLK27M_PASSWORD_I	0x18
>>> +#define IOP_CLK27M_PASSWORD_II	0x1c
>>> +#define IOP_PMC_TIMER2		0x20
>>> +
>>> +/* Max size of poweroff.bin that can be received */ #define
>>> +POWEROFF_CODE_MAX_SIZE 0x4000
>>> +
>>> +/* 8051 informs linux kerenl. 8051 has been switched to poweroff.bin code.
>> */
>>> +#define IOP_READY	0x0004
>>> +#define RISC_READY	0x0008
>>> +
>>> +/* System linux kernel tells 8051 which  gpio pin to wake-up through. */
>>> +#define WAKEUP_PIN	0xFE02
>>> +
>>> +/*
>>> + * There are 3 power domains in SP7021, AO domain, IOP domain,
>>> + * Default domain. Default domain is linux kernel system.
>>> + * System linux kernel tells 8051 to execute power off.
>>> + */
>>> +#define DEFAULT_DOMAIN_POWEROFF	0x5331 /* AO&IOP domain on,
>> Default domain off */
>>> +#define DEFAULT_AND_IOP_DOMAIN_POWEROFF	0x5333 /* AO domain
>> on, IOP&Default domain off */
>>> +
>>> +struct sp_iop {
>>> +	struct device *dev;
>>> +	struct clk *iopclk;
>>> +	struct reset_control *rstc;
>>> +	void __iomem *iop_regs;
>>> +	void __iomem *pmc_regs;
>>> +	void __iomem *moon0_regs;
>>> +	int irq;
>>> +	int gpio_wakeup;
>>> +	resource_size_t iop_mem_start;
>>> +	resource_size_t iop_mem_size;
>>> +	unsigned char bin_code_mode;
>>> +};
>>> +
>>> +static struct sp_iop *iop_poweroff;
>>> +
>>> +static void sp_iop_load_normal_code(struct sp_iop *iop) {
>>> +	const struct firmware *fw;
>>> +	void __iomem *iop_kernel_base;
>>> +	unsigned int reg, err;
>>> +
>>> +	err = request_firmware(&fw, "normal.bin", iop->dev);
>>> +	if (err)
>>> +		dev_err(iop->dev, "get bin file error\n");
>>> +
>>> +	iop_kernel_base = ioremap(iop->iop_mem_start, fw->size);
>>> +	memset(iop_kernel_base, 0, fw->size);
>>> +	memcpy(iop_kernel_base, fw->data, fw->size);
>>> +	release_firmware(fw);
>>> +
>>> +	clk_prepare_enable(iop->iopclk);
>>
>> where do you disable the clock?
> 
> I will add disable clock in sp_iop_remove().				
> Below is my modification				
> static int sp_iop_remove(struct platform_device *pdev)				
> {				
> 	struct sp_iop *iop = iop_poweroff;			
> 	pm_power_off = NULL;			
> 	clk_disable_unprepare(iop->iopclk);			
> 				
> 	return 0;			
> }				

How is it balanced then? remove() is symmetric to probe() but you did
not enable clocks in the probe(). Instead you enable the clocks each
time in load_normal_code() and load_poweroff_code().

This does not seem right at all.

Best regards,
Krzysztof