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Message-ID: <00362767-080a-aa7f-672f-22b83ab35e61@kernel.org>
Date:   Sun, 13 Mar 2022 10:43:33 +0100
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Subject: Re: [PATCH v11 2/2] misc: Add iop driver for Sunplus SP7021
Content-Language: en-US
To:     Tony Huang <tonyhuang.sunplus@gmail.com>, robh+dt@kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        derek.kiernan@xilinx.com, dragan.cvetic@xilinx.com, arnd@arndb.de,
        gregkh@linuxfoundation.org
Cc:     wells.lu@sunplus.com, tony.huang@sunplus.com
References: <cover.1647095774.git.tonyhuang.sunplus@gmail.com>
 <07f507a84a9e39d3cd8393f41d1292c250e07642.1647095774.git.tonyhuang.sunplus@gmail.com>
From:   Krzysztof Kozlowski <krzk@kernel.org>
In-Reply-To: <07f507a84a9e39d3cd8393f41d1292c250e07642.1647095774.git.tonyhuang.sunplus@gmail.com>
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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?

>  - 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/? sp_iop_poweroff is
still here.

>  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?

> +
> +	reg = readl(iop->iop_regs + IOP_CONTROL);
> +	reg |= 0x01;
> +	writel(reg, iop->iop_regs + IOP_CONTROL);
> +

(...)

> +static int sp_iop_get_resources(struct platform_device *pdev, struct sp_iop *p_sp_iop_info)
> +{
> +	struct resource *r;
> +
> +	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "iop");
> +	p_sp_iop_info->iop_regs = devm_ioremap_resource(&pdev->dev, r);
> +	if (IS_ERR(p_sp_iop_info->iop_regs)) {
> +		dev_err(&pdev->dev, "ioremap fail\n");
> +		return PTR_ERR(p_sp_iop_info->iop_regs);
> +	}
> +
> +	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "iop_pmc");
> +	p_sp_iop_info->pmc_regs = devm_ioremap_resource(&pdev->dev, r);
> +	if (IS_ERR(p_sp_iop_info->pmc_regs)) {
> +		dev_err(&pdev->dev, "ioremap fail\n");
> +		return PTR_ERR(p_sp_iop_info->pmc_regs);
> +	}
> +
> +	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "moon0");
> +	p_sp_iop_info->moon0_regs = devm_ioremap_resource(&pdev->dev, r);
> +	if (IS_ERR(p_sp_iop_info->moon0_regs)) {
> +		dev_err(&pdev->dev, "ioremap fail\n");
> +		return PTR_ERR(p_sp_iop_info->moon0_regs);
> +	}
> +	return 0;

https://lore.kernel.org/all/16d98dfa-66f9-f9a4-08c9-d68d78c33b23@canonical.com/
You received a comment about adding blank lines before return. This has
to be done everywhere.

> +}
> +
> +static int sp_iop_platform_driver_probe(struct platform_device *pdev)

Do not add "platform_driver" suffix to functions. "_probe" is enough.

> +{
> +	int ret = -ENXIO;
> +	int rc;
> +	struct sp_iop *iop;
> +	struct device_node *memnp;
> +	struct resource mem_res;
> +
> +	iop = devm_kzalloc(&pdev->dev, sizeof(struct sp_iop), GFP_KERNEL);
> +	if (!iop) {
> +		ret = -ENOMEM;
> +		goto fail_kmalloc;
> +	}
> +
> +	ret = sp_iop_get_resources(pdev, iop);
> +
> +	/* Get reserve address. */
> +	memnp = of_parse_phandle(pdev->dev.of_node, "memory-region", 0);
> +	if (!memnp) {
> +		dev_err(&pdev->dev, "no memory-region node\n");
> +		return -EINVAL;
> +	}
> +
> +	rc = of_address_to_resource(memnp, 0, &mem_res);
> +	of_node_put(memnp);
> +	if (rc) {
> +		dev_err(&pdev->dev, "failed to translate memory-region to a resource\n");
> +		return -EINVAL;
> +	}
> +
> +	iop->dev = &pdev->dev;
> +	iop->iop_mem_start = mem_res.start;
> +	iop->iop_mem_size = resource_size(&mem_res);
> +	iop->iopclk = devm_clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(iop->iopclk))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(iop->iopclk),
> +					    "devm_clk_get fail\n");

Clocks are not documented but required in bindings?

> +
> +	/*
> +	 * 8051 has two bin files, normal.bin and poweroff.bin in rootfs.
> +	 * Normally, 8051 executes normal.bin code. Normal.bin code size can exceed 16K.
> +	 */
> +	sp_iop_load_normal_code(iop);
> +
> +	platform_set_drvdata(pdev, iop);
> +	iop->gpio_wakeup = of_get_named_gpio(pdev->dev.of_node, "iop-wakeup", 0);

It's not in the bindings. Do not add undocumented properties. Everything
has to be in the bindings. I don't see usage of generic wakeup-gpios, so
this all looks untested. You didn't run this code, did you?

> +	iop_poweroff = iop;
> +	pm_power_off = sp_iop_poweroff;
> +
> +	return 0;
> +
> +fail_kmalloc:
> +	return ret;
> +}
> +
> +static int sp_iop_remove(struct platform_device *pdev)
> +{
> +	pm_power_off = NULL;
> +	return 0;
> +}
> +
> +static const struct of_device_id sp_iop_of_match[] = {
> +	{ .compatible = "sunplus,sp7021-iop" },
> +	{ /* sentinel */ },
> +};
> +
> +MODULE_DEVICE_TABLE(of, sp_iop_of_match);
> +
> +static struct platform_driver sp_iop_platform_driver = {
> +	.probe		= sp_iop_platform_driver_probe,
> +	.remove		= sp_iop_remove,
> +	.driver = {
> +		.name	= "sunplus,sp7021-iop",
> +		.of_match_table = sp_iop_of_match,
> +	}
> +};
> +
> +module_platform_driver(sp_iop_platform_driver);
> +
> +MODULE_AUTHOR("Tony Huang <tonyhuang.sunplus@gmail.com>");
> +MODULE_DESCRIPTION("Sunplus IOP Driver");
> +MODULE_LICENSE("GPL v2");


Best regards,
Krzysztof