linux-kernel - Re: [PATCH v12 2/3] spi: Add Renesas R-Car Gen3 RPC-IF SPI controller driver

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Message-ID: <20190514065216.GL4319@dell>
Date:   Tue, 14 May 2019 07:52:16 +0100
From:   Lee Jones <lee.jones@...aro.org>
To:     Mason Yang <masonccyang@...c.com.tw>
Cc:     broonie@...nel.org, marek.vasut@...il.com,
        linux-kernel@...r.kernel.org, linux-spi@...r.kernel.org,
        bbrezillon@...nel.org, linux-renesas-soc@...r.kernel.org,
        Geert Uytterhoeven <geert+renesas@...der.be>,
        sergei.shtylyov@...entembedded.com, robh+dt@...nel.org,
        mark.rutland@....com, devicetree@...r.kernel.org,
        juliensu@...c.com.tw, Simon Horman <horms@...ge.net.au>,
        zhengxunli@...c.com.tw
Subject: Re: [PATCH v12 2/3] spi: Add Renesas R-Car Gen3 RPC-IF SPI
 controller driver

On Wed, 24 Apr 2019, Mason Yang wrote:

> Add a driver for Renesas R-Car Gen3 RPC-IF SPI controller.
> 
> Signed-off-by: Mason Yang <masonccyang@...c.com.tw>
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@...entembedded.com>
> ---
>  drivers/spi/Kconfig           |   6 +
>  drivers/spi/Makefile          |   1 +
>  drivers/spi/spi-renesas-rpc.c | 571 ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 578 insertions(+)
>  create mode 100644 drivers/spi/spi-renesas-rpc.c
> 
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index f761655..1f52bcf 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -564,6 +564,12 @@ config SPI_RSPI
>  	help
>  	  SPI driver for Renesas RSPI and QSPI blocks.
>  
> +config SPI_RENESAS_RPC
> +	tristate "Renesas R-Car Gen3 RPC-IF controller"
> +	depends on ARCH_RENESAS || COMPILE_TEST
> +	help
> +	  SPI driver for Renesas R-Car Gen3 RPC-IF.
> +
>  config SPI_QCOM_QSPI
>  	tristate "QTI QSPI controller"
>  	depends on ARCH_QCOM
> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
> index d8fc03c..b3a3deb 100644
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -86,6 +86,7 @@ obj-$(CONFIG_SPI_QUP)			+= spi-qup.o
>  obj-$(CONFIG_SPI_ROCKCHIP)		+= spi-rockchip.o
>  obj-$(CONFIG_SPI_RB4XX)			+= spi-rb4xx.o
>  obj-$(CONFIG_SPI_RSPI)			+= spi-rspi.o
> +obj-$(CONFIG_SPI_RENESAS_RPC)		+= spi-renesas-rpc.o
>  obj-$(CONFIG_SPI_S3C24XX)		+= spi-s3c24xx-hw.o
>  spi-s3c24xx-hw-y			:= spi-s3c24xx.o
>  spi-s3c24xx-hw-$(CONFIG_SPI_S3C24XX_FIQ) += spi-s3c24xx-fiq.o
> diff --git a/drivers/spi/spi-renesas-rpc.c b/drivers/spi/spi-renesas-rpc.c
> new file mode 100644
> index 0000000..c2202d4
> --- /dev/null
> +++ b/drivers/spi/spi-renesas-rpc.c
> @@ -0,0 +1,571 @@
> +// SPDX-License-Identifier: GPL-2.0
> +//
> +// Copyright (C) 2018 ~ 2019 Renesas Solutions Corp.
> +// Copyright (C) 2019 Macronix International Co., Ltd.
> +//
> +// R-Car Gen3 RPC-IF SPI/QSPI/Octa driver
> +//
> +// Author:
> +//	Mason Yang <masonccyang@...c.com.tw>
> +//
> +
> +#include <linux/clk.h>
> +#include <linux/io.h>
> +#include <linux/log2.h>
> +#include <linux/iopoll.h>
> +#include <linux/mfd/renesas-rpc.h>
> +#include <linux/module.h>
> +#include <linux/mtd/mtd.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
> +#include <linux/reset.h>
> +#include <linux/spi/spi.h>
> +#include <linux/spi/spi-mem.h>
> +
> +#include <asm/unaligned.h>
> +
> +struct rpc_spi {
> +	struct rpc_mfd *mfd;

The term MFD isn't a real thing.  What you're obtaining below is
driver data and is normally articulated as 'ddata' in drivers.

> +	u32 cur_speed_hz;
> +	u32 cmd;
> +	u32 addr;
> +	u32 dummy;
> +	u32 smcr;
> +	u32 smenr;
> +	u32 xferlen;
> +	u32 totalxferlen;
> +	enum spi_mem_data_dir xfer_dir;
> +};

[...]

> +static void rpc_spi_hw_init(struct rpc_spi *rpc)
> +{
> +	//
> +	// NOTE: The 0x260 are undocumented bits, but they must be set.
> +	//	 RPC_PHYCNT_STRTIM is strobe timing adjustment bit,
> +	//	 0x0 : the delay is biggest,
> +	//	 0x1 : the delay is 2nd biggest,
> +	//	 On H3 ES1.x, the value should be 0, while on others,
> +	//	 the value should be 6.
> +	//

C++ style comments?  Is that a thing now?

> +	regmap_write(rpc->mfd->regmap, RPC_PHYCNT, RPC_PHYCNT_CAL |
> +				  RPC_PHYCNT_STRTIM(6) | 0x260);
> +
> +	//
> +	// NOTE: The 0x1511144 are undocumented bits, but they must be set
> +	//       for RPC_PHYOFFSET1.
> +	//	 The 0x31 are undocumented bits, but they must be set
> +	//	 for RPC_PHYOFFSET2.
> +	//
> +	regmap_write(rpc->mfd->regmap, RPC_PHYOFFSET1,
> +		     RPC_PHYOFFSET1_DDRTMG(3) | 0x1511144);
> +	regmap_write(rpc->mfd->regmap, RPC_PHYOFFSET2, 0x31 |
> +		     RPC_PHYOFFSET2_OCTTMG(4));
> +	regmap_write(rpc->mfd->regmap, RPC_SSLDR, RPC_SSLDR_SPNDL(7) |
> +		     RPC_SSLDR_SLNDL(7) | RPC_SSLDR_SCKDL(7));
> +	regmap_write(rpc->mfd->regmap, RPC_CMNCR, RPC_CMNCR_MD |
> +		     RPC_CMNCR_SFDE | RPC_CMNCR_MOIIO_HIZ | RPC_CMNCR_IOFV_HIZ |
> +		     RPC_CMNCR_BSZ(0));
> +}

-- 
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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