Re: [PATCH v5 1/3] mmc: dw_mmc-bluefield: Add driver extension

[Shawn Lin <shawn.lin@rock-chips.com>]

On 2018/5/2 20:45, Liming Sun wrote:
> Please see response inline.
> 
> Thanks,
> Liming
> 
>> -----Original Message-----
>> From: Shawn Lin [mailto:shawn.lin@rock-chips.com]
>> Sent: Tuesday, May 1, 2018 9:02 PM
>> To: Liming Sun <lsun@mellanox.com>; Mark Rutland
>> <mark.rutland@arm.com>; Jaehoon Chung <jh80.chung@samsung.com>;
>> Catalin Marinas <catalin.marinas@arm.com>; Will Deacon
>> <will.deacon@arm.com>
>> Cc: Ulf Hansson <ulf.hansson@linaro.org>; Rob Herring
>> <robh+dt@kernel.org>; shawn.lin@rock-chips.com; linux-
>> mmc@vger.kernel.org; devicetree@vger.kernel.org; linux-
>> kernel@vger.kernel.org; stable@kernel.org
>> Subject: Re: [PATCH v5 1/3] mmc: dw_mmc-bluefield: Add driver extension
>>
>> On 2018/5/2 2:19, Liming Sun wrote:
>>> This commit adds extension to the dw_mmc driver for Mellanox BlueField
>>> SoC. It updates the UHS_REG_EXT register to bring up the eMMC card on
>>> this SoC.
>>>
>>> Cc: stable@kernel.org
>>
>> Why?
> 
> [Liming] This is recommended value from HW team. Without this setting, the eMMC
> controller and cards can be found in Linux, but not stable. Writing to it could caused
> CRC error.

Well, I refered to the "Cc: stable@kernel.org" in the commit msg.

> 
>>
>>> Signed-off-by: Liming Sun <lsun@mellanox.com>
>>> Reviewed-by: David Woods <dwoods@mellanox.com>
>>> ---
>>>    drivers/mmc/host/Kconfig            |  9 +++++
>>>    drivers/mmc/host/Makefile           |  1 +
>>>    drivers/mmc/host/dw_mmc-bluefield.c | 72
>> +++++++++++++++++++++++++++++++++++++
>>>    3 files changed, 82 insertions(+)
>>>    create mode 100644 drivers/mmc/host/dw_mmc-bluefield.c
>>>
>>> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
>>> index 9589f9c..26ac6b5 100644
>>> --- a/drivers/mmc/host/Kconfig
>>> +++ b/drivers/mmc/host/Kconfig
>>> @@ -717,6 +717,15 @@ config MMC_DW_K3
>>>    	  Synopsys DesignWare Memory Card Interface driver. Select this
>> option
>>>    	  for platforms based on Hisilicon K3 SoC's.
>>>
>>> +config MMC_DW_BLUEFIELD
>>
>> And did you have feedback of my comment in V2？
>> http://lists-archives.com/linux-kernel/29104830-mmc-dw_mmc-bluefield-
>> add-driver-extension.html
>>
>>> +	tristate "BlueField specific extensions for Synopsys DW Memory Card
>> Interface"
>>> +	depends on MMC_DW
>>> +	select MMC_DW_PLTFM
>>> +	help
>>> +	  This selects support for Mellanox BlueField SoC specific extensions
>> to
>>> +	  the Synopsys DesignWare Memory Card Interface driver. Select this
>>> +	  option for platforms based on Mellanox BlueField SoC's.
>>> +
>>>    config MMC_DW_PCI
>>>    	tristate "Synopsys Designware MCI support on PCI bus"
>>>    	depends on MMC_DW && PCI
>>> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
>>> index 6aead24..267b3f1 100644
>>> --- a/drivers/mmc/host/Makefile
>>> +++ b/drivers/mmc/host/Makefile
>>> @@ -55,6 +55,7 @@ obj-$(CONFIG_MMC_DW_K3)		+= dw_mmc-
>> k3.o
>>>    obj-$(CONFIG_MMC_DW_PCI)	+= dw_mmc-pci.o
>>>    obj-$(CONFIG_MMC_DW_ROCKCHIP)	+= dw_mmc-rockchip.o
>>>    obj-$(CONFIG_MMC_DW_ZX)		+= dw_mmc-zx.o
>>> +obj-$(CONFIG_MMC_DW_BLUEFIELD)	+= dw_mmc-bluefield.o
>>>    obj-$(CONFIG_MMC_SH_MMCIF)	+= sh_mmcif.o
>>>    obj-$(CONFIG_MMC_JZ4740)	+= jz4740_mmc.o
>>>    obj-$(CONFIG_MMC_VUB300)	+= vub300.o
>>> diff --git a/drivers/mmc/host/dw_mmc-bluefield.c
>> b/drivers/mmc/host/dw_mmc-bluefield.c
>>> new file mode 100644
>>> index 0000000..12067b1
>>> --- /dev/null
>>> +++ b/drivers/mmc/host/dw_mmc-bluefield.c
>>> @@ -0,0 +1,72 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +/*
>>> + * Copyright (C) 2018 Mellanox Technologies.
>>> + *
>>> + * 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.
>>> + */
>>> +
>>> +#include <linux/module.h>
>>> +#include <linux/io.h>
>>> +#include <linux/irq.h>
>>> +#include <linux/platform_device.h>
>>> +#include <linux/pm_runtime.h>
>>> +#include <linux/mmc/host.h>
>>> +#include <linux/mmc/mmc.h>
>>> +#include <linux/of.h>
>>> +
>>> +#include "dw_mmc.h"
>>> +#include "dw_mmc-pltfm.h"
>>> +
>>> +static void dw_mci_bluefield_set_ios(struct dw_mci *host, struct
>> mmc_ios *ios)
>>> +{
>>> +	u32 regs;
>>> +
>>> +	/* Set drive=4 (bit 29:23) and sample=2 (bit 22:16) in UHS_REG_EXT.
>> */
>>> +	regs = mci_readl(host, UHS_REG_EXT);
>>> +	regs = (regs & ~0x3F100000 & ~0x7F0000) | (4 << 23) | (2 << 16);
>>> +	mci_writel(host, UHS_REG_EXT, regs);
>>> +}
>>> +
>>> +static const struct dw_mci_drv_data bluefield_drv_data = {
>>> +	.set_ios		= dw_mci_bluefield_set_ios
>>> +};
>>> +
>>> +static const struct of_device_id dw_mci_bluefield_match[] = {
>>> +	{ .compatible = "mellanox,bluefield-dw-mshc",
>>> +		.data = &bluefield_drv_data },
>>> +	{},
>>> +};
>>> +MODULE_DEVICE_TABLE(of, dw_mci_bluefield_match);
>>> +
>>> +static int dw_mci_bluefield_probe(struct platform_device *pdev)
>>> +{
>>> +	const struct dw_mci_drv_data *drv_data = NULL;
>>> +	const struct of_device_id *match;
>>> +
>>> +	if (pdev->dev.of_node) {
>>> +		match = of_match_node(dw_mci_bluefield_match,
>>> +				      pdev->dev.of_node);
>>> +		drv_data = match->data;
>>> +	}
>>> +
>>> +	return dw_mci_pltfm_register(pdev, drv_data);
>>> +}
>>> +
>>> +static struct platform_driver dw_mci_bluefield_pltfm_driver = {
>>> +	.probe		= dw_mci_bluefield_probe,
>>> +	.remove		= dw_mci_pltfm_remove,
>>> +	.driver		= {
>>> +		.name		= "dwmmc_bluefield",
>>> +		.of_match_table	= dw_mci_bluefield_match,
>>> +		.pm		= &dw_mci_pltfm_pmops,
>>> +	},
>>> +};
>>> +
>>> +module_platform_driver(dw_mci_bluefield_pltfm_driver);
>>> +
>>> +MODULE_DESCRIPTION("BlueField DW Multimedia Card driver");
>>> +MODULE_AUTHOR("Mellanox Technologies");
>>> +MODULE_LICENSE("GPL v2");
>>>
> 
> 
> 
>