linux-kernel - Re: [PATCH 2/2] sdhci-of-arasan: Set controller to test mode when fails-without-test-cd is present

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Message-ID: <b557b08d-a401-3592-6817-8e0d5936f764@xilinx.com>
Date:   Wed, 7 Sep 2016 07:13:17 +0200
From:   Michal Simek <michal.simek@...inx.com>
To:     Zach Brown <zach.brown@...com>,
        Michal Simek <michal.simek@...inx.com>
CC:     <adrian.hunter@...el.com>, <robh+dt@...nel.org>,
        <ulf.hansson@...aro.org>, <mark.rutland@....com>,
        <linux-mmc@...r.kernel.org>, <devicetree@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <soren.brinkmann@...inx.com>,
        <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH 2/2] sdhci-of-arasan: Set controller to test mode when
 fails-without-test-cd is present

On 6.9.2016 20:51, Zach Brown wrote:
> On Tue, Aug 30, 2016 at 07:47:17AM +0200, Michal Simek wrote:
>> On 30.8.2016 01:20, Zach Brown wrote:
>>> The sdhci controller on xilinx zynq devices will not function unless
>>> the CD bit is provided. http://www.xilinx.com/support/answers/61064.html
>>> In cases where it is impossible to provide the CD bit in hardware,
>>> setting the controller to test mode and then setting inserted to true
>>> will get the controller to function without the CD bit.
>>>
>>> When the device has the property fails-without-test-cd the driver
>>> changes the controller to test mode and sets test inserted to true to
>>> make the controller function.
>>>
>>> Signed-off-by: Zach Brown <zach.brown@...com>
>>> ---
>>>  drivers/mmc/host/sdhci-of-arasan.c | 34 +++++++++++++++++++++++++++++++++-
>>>  drivers/mmc/host/sdhci.h           |  2 ++
>>>  2 files changed, 35 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
>>> index e0f193f..c3e5145 100644
>>> --- a/drivers/mmc/host/sdhci-of-arasan.c
>>> +++ b/drivers/mmc/host/sdhci-of-arasan.c
>>> @@ -26,6 +26,7 @@
>>>  #include <linux/phy/phy.h>
>>>  #include <linux/regmap.h>
>>>  #include "sdhci-pltfm.h"
>>> +#include <linux/of.h>
>>>
>>>  #define SDHCI_ARASAN_CLK_CTRL_OFFSET	0x2c
>>>  #define SDHCI_ARASAN_VENDOR_REGISTER	0x78
>>> @@ -92,6 +93,12 @@ struct sdhci_arasan_data {
>>>
>>>  	struct regmap	*soc_ctl_base;
>>>  	const struct sdhci_arasan_soc_ctl_map *soc_ctl_map;
>>> +
>>> +	unsigned int arasan_quirks; /* Arasan deviations from spec */
>>> +
>>> +/* Controller does not have CD wired and will not function normally without */
>>> +#define SDHCI_ARASAN_QUIRK_FAILS_WITHOUT_TEST_CD (1<<0)
>>
>> Bit macro instead?
>>
> 
> Setting bits with notations like (1<<0) is the style which is used for quirks
> in sdhci.h Is there a reason it should be different here?

sdhci.h is here for a long time and IIRC using BIT macro is recommended way.


>>> +
>>
>> remove this line.
>>
>>>  };
>>>
>>>  static const struct sdhci_arasan_soc_ctl_map rk3399_soc_ctl_map = {
>>> @@ -203,12 +210,32 @@ static void sdhci_arasan_hs400_enhanced_strobe(struct mmc_host *mmc,
>>>  	writel(vendor, host->ioaddr + SDHCI_ARASAN_VENDOR_REGISTER);
>>>  }
>>>
>>> +void sdhci_arasan_reset(struct sdhci_host *host, u8 mask)
>>> +{
>>> +	u8 ctrl;
>>> +	struct sdhci_pltfm_host *pltfm_host;
>>> +	struct sdhci_arasan_data *sdhci_arasan;
>>> +
>>> +	sdhci_reset(host, mask);
>>> +
>>> +	pltfm_host = sdhci_priv(host);
>>> +	sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
>>> +
>>> +	if (sdhci_arasan->arasan_quirks &
>>> +	    SDHCI_ARASAN_QUIRK_FAILS_WITHOUT_TEST_CD) {
>>> +		ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
>>> +		ctrl |= SDHCI_CTRL_CDTEST_INS |
>>> +			SDHCI_CTRL_CDTEST_EN;
>>> +		sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
>>> +	}
>>> +}
>>> +
>>>  static struct sdhci_ops sdhci_arasan_ops = {
>>>  	.set_clock = sdhci_arasan_set_clock,
>>>  	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
>>>  	.get_timeout_clock = sdhci_arasan_get_timeout_clock,
>>>  	.set_bus_width = sdhci_set_bus_width,
>>> -	.reset = sdhci_reset,
>>> +	.reset = sdhci_arasan_reset,
>>>  	.set_uhs_signaling = sdhci_set_uhs_signaling,
>>>  };
>>>
>>> @@ -516,6 +543,11 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
>>>  	}
>>>
>>>  	sdhci_get_of_property(pdev);
>>> +
>>> +	if (of_get_property(pdev->dev.of_node, "fails-without-test-cd", NULL))
>>> +		sdhci_arasan->arasan_quirks |=
>>> +				SDHCI_ARASAN_QUIRK_FAILS_WITHOUT_TEST_CD;
>>> +
>>>  	pltfm_host->clk = clk_xin;
>>>
>>>  	sdhci_arasan_update_baseclkfreq(host);
>>> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
>>> index 0411c9f..8d92d6e9 100644
>>> --- a/drivers/mmc/host/sdhci.h
>>> +++ b/drivers/mmc/host/sdhci.h
>>> @@ -84,6 +84,8 @@
>>>  #define   SDHCI_CTRL_ADMA32	0x10
>>>  #define   SDHCI_CTRL_ADMA64	0x18
>>>  #define   SDHCI_CTRL_8BITBUS	0x20
>>> +#define  SDHCI_CTRL_CDTEST_INS   0x40
>>> +#define  SDHCI_CTRL_CDTEST_EN     0x80
>>
>> You should follow coding style above.
> 
> I don't understand the issue you're raising. Could you elaborate?

Origin format is
#define<space><space>MACRO_NAME<tab>MACRO_VALUE

What you have above is not following this style.
You should turn on tab highlighting in your editor.

Thanks,
Michal