Re: [PATCH v3 2/3] spi: Add Amlogic SPISG driver

[Krzysztof Kozlowski <krzk@kernel.org>]

On 23/06/2025 10:53, Xianwei Zhao via B4 Relay wrote:
> From: Sunny Luo <sunny.luo@amlogic.com>
> 
> Introduced support for the new SPI IP (SPISG) driver. The SPISG is
> a communication-oriented SPI controller from Amlogic,supporting
> three operation modes: PIO, block DMA, and scatter-gather DMA.
> 
> Signed-off-by: Sunny Luo <sunny.luo@amlogic.com>
> Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
> ---
>  drivers/spi/Kconfig             |   9 +
>  drivers/spi/Makefile            |   1 +
>  drivers/spi/spi-amlogic-spisg.c | 876 ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 886 insertions(+)
> 
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index c51da3fc3604..e11341df2ecf 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -99,6 +99,15 @@ config SPI_AMLOGIC_SPIFC_A1
>  	  This enables master mode support for the SPIFC (SPI flash
>  	  controller) available in Amlogic A1 (A113L SoC).
>  
> +config SPI_AMLOGIC_SPISG
> +	tristate "Amlogic SPISG controller"
> +	depends on COMMON_CLK
> +	depends on ARCH_MESON || COMPILE_TEST
> +	help
> +	  This enables master mode support for the SPISG (SPI scatter-gather
> +	  communication controller), which is available on platforms such as
> +	  Amlogic A4 SoCs.
> +
>  config SPI_APPLE
>  	tristate "Apple SoC SPI Controller platform driver"
>  	depends on ARCH_APPLE || COMPILE_TEST
> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
> index 4ea89f6fc531..b74e3104d71f 100644
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -20,6 +20,7 @@ obj-$(CONFIG_SPI_ALTERA)		+= spi-altera-platform.o
>  obj-$(CONFIG_SPI_ALTERA_CORE)		+= spi-altera-core.o
>  obj-$(CONFIG_SPI_ALTERA_DFL)		+= spi-altera-dfl.o
>  obj-$(CONFIG_SPI_AMLOGIC_SPIFC_A1)	+= spi-amlogic-spifc-a1.o
> +obj-$(CONFIG_SPI_AMLOGIC_SPISG)		+= spi-amlogic-spisg.o
>  obj-$(CONFIG_SPI_APPLE)			+= spi-apple.o
>  obj-$(CONFIG_SPI_AR934X)		+= spi-ar934x.o
>  obj-$(CONFIG_SPI_ARMADA_3700)		+= spi-armada-3700.o
> diff --git a/drivers/spi/spi-amlogic-spisg.c b/drivers/spi/spi-amlogic-spisg.c
> new file mode 100644
> index 000000000000..2f2982154d49
> --- /dev/null
> +++ b/drivers/spi/spi-amlogic-spisg.c
> @@ -0,0 +1,876 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Driver for Amlogic SPI communication Scatter-Gather Controller
> + *
> + * Copyright (C) 2025 Amlogic, Inc. All rights reserved
> + *
> + * Author: Sunny Luo <sunny.luo@amlogic.com>
> + * Author: Xianwei Zhao <xianwei.zhao@amlogic.com>
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/clk.h>
> +#include <linux/device.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/clk-provider.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/pm_domain.h>

cacheflush

> +#include <linux/platform_device.h>
> +#include <linux/spi/spi.h>
> +#include <linux/types.h>
> +#include <linux/interrupt.h>
> +#include <linux/reset.h>

So this you take to reset device... but your device does not have any
resets! Just look at your binding.

> +#include <linux/pinctrl/consumer.h>
> +#include <linux/delay.h>
> +#include <linux/cacheflush.h>

Where do you use it?

> +#include <linux/regmap.h>

Actually several other headers looks unused. I am not going to keep
checking one by one - you should check and do not include irrelevant
headers.

> +
> +static int aml_spisg_probe(struct platform_device *pdev)
> +{
> +	struct spi_controller *ctlr;
> +	struct spisg_device *spisg;
> +	struct device *dev = &pdev->dev;
> +	void __iomem *base;
> +	int ret, irq;
> +
> +	const struct regmap_config aml_regmap_config = {
> +		.reg_bits = 32,
> +		.val_bits = 32,
> +		.reg_stride = 4,
> +		.max_register = SPISG_MAX_REG,
> +	};
> +
> +	if (of_property_read_bool(dev->of_node, "slave"))

"slave" is not a bool. You want to check for child presence, don't you?
You need to use appropriate API for that otherwise you just add one of
the issues which was being fixed recently.

> +		ctlr = spi_alloc_target(dev, sizeof(*spisg));
> +	else
> +		ctlr = spi_alloc_host(dev, sizeof(*spisg));
> +	if (!ctlr)
> +		return dev_err_probe(dev, -ENOMEM, "controller allocation failed\n");
> +



> +
> +static struct platform_driver amlogic_spisg_driver = {
> +	.probe = aml_spisg_probe,
> +	.remove = aml_spisg_remove,
> +	.driver  = {
> +		.name = "amlogic-spisg",
> +		.of_match_table = of_match_ptr(amlogic_spisg_of_match),

So now you will have warnings... drop of_match_ptr.

Both suggest you send us some old code, instead of working on something
recent.

> +		.pm = &amlogic_spisg_pm_ops,
> +	},
> +};
> +
> +module_platform_driver(amlogic_spisg_driver);
> +
> +MODULE_DESCRIPTION("Amlogic SPI Scatter-Gather Controller driver");
> +MODULE_AUTHOR("Sunny Luo <sunny.luo@amlogic.com>");
> +MODULE_LICENSE("GPL");
> 


Best regards,
Krzysztof