diff mbox

[v4,9/9] mmc: dw_mmc: add support for exynos specific implementation of dw-mshc

Message ID 1345981927-26359-10-git-send-email-thomas.abraham@linaro.org
State New
Headers show

Commit Message

thomas.abraham@linaro.org Aug. 26, 2012, 11:52 a.m. UTC
Samsung Exynos SoC's extend the dw-mshc controller for additional clock and bus
control. Add support for these extensions and include provide device tree based
discovery suppory as well.

Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
---
 .../devicetree/bindings/mmc/exynos-dw-mshc.txt     |   79 +++++++
 drivers/mmc/host/Kconfig                           |    9 +
 drivers/mmc/host/Makefile                          |    3 +-
 drivers/mmc/host/dw_mmc-exynos.c                   |  247 ++++++++++++++++++++
 4 files changed, 337 insertions(+), 1 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
 create mode 100644 drivers/mmc/host/dw_mmc-exynos.c

Comments

Jaehoon Chung Aug. 27, 2012, 8:58 a.m. UTC | #1
Hi Thomas,

> +	gpio = of_get_named_gpio(slot_np, "wp-gpios", 0);
> +	if (gpio_is_valid(gpio)) {
> +		if (devm_gpio_request(host->dev, gpio, "dw-mci-wp"))
> +			dev_info(host->dev, "gpio [%d] request failed\n",
> +						gpio);
> +	} else {
> +		dev_info(host->dev, "wp gpio not available");
> +		host->pdata->quirks |= DW_MCI_QUIRK_NO_WRITE_PROTECT;
> +	}
> +
> +	if (host->pdata->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)
> +		return 0;
> +
> +	gpio = of_get_named_gpio(slot_np, "samsung,cd-pinmux-gpio", 0);
> +	if (gpio_is_valid(gpio)) {
> +		if (devm_gpio_request(host->dev, gpio, "dw-mci-cd"))
I'm not sure, but i saw mmc_gpio_request_cd() into drivers/mmc/core/slot-gpio.c.
Can we use this? i think we can use them.
Just my opinion.

Best Regards,
Jaehoon Chung
> +			dev_err(host->dev, "gpio [%d] request failed\n", gpio);
> +	} else {
> +		dev_info(host->dev, "cd gpio not available");
> +	}
> +
> +	return 0;
> +}
> +
> +/* Exynos5250 controller specific capabilities */
> +static unsigned long exynos5250_dwmmc_caps[4] = {
> +	MMC_CAP_UHS_DDR50 | MMC_CAP_1_8V_DDR |
> +		MMC_CAP_8_BIT_DATA | MMC_CAP_CMD23,
> +	MMC_CAP_CMD23,
> +	MMC_CAP_CMD23,
> +	MMC_CAP_CMD23,
> +};
> +
> +static struct dw_mci_drv_data exynos5250_drv_data = {
> +	.caps			= exynos5250_dwmmc_caps,
> +	.init			= dw_mci_exynos_priv_init,
> +	.prepare_command	= dw_mci_exynos_prepare_command,
> +	.set_ios		= dw_mci_exynos_set_ios,
> +	.parse_dt		= dw_mci_exynos_parse_dt,
> +	.setup_bus		= dw_mci_exynos_setup_bus,
> +};
> +
> +static const struct of_device_id dw_mci_exynos_match[] = {
> +	{ .compatible = "samsung,exynos5250-dw-mshc",
> +			.data = (void *)&exynos5250_drv_data, },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, dw_mci_pltfm_match);
> +
> +int dw_mci_exynos_probe(struct platform_device *pdev)
> +{
> +	struct dw_mci_drv_data *drv_data;
> +	const struct of_device_id *match;
> +
> +	match = of_match_node(dw_mci_exynos_match, pdev->dev.of_node);
> +	drv_data = match->data;
> +	return dw_mci_pltfm_register(pdev, drv_data);
> +}
> +
> +static struct platform_driver dw_mci_exynos_pltfm_driver = {
> +	.probe		= dw_mci_exynos_probe,
> +	.remove		= __exit_p(dw_mci_pltfm_remove),
> +	.driver		= {
> +		.name		= "dwmmc_exynos",
> +		.of_match_table	= of_match_ptr(dw_mci_exynos_match),
> +		.pm		= &dw_mci_pltfm_pmops,
> +	},
> +};
> +
> +module_platform_driver(dw_mci_exynos_pltfm_driver);
> +
> +MODULE_DESCRIPTION("Samsung Specific DW-MSHC Driver Extension");
> +MODULE_AUTHOR("Thomas Abraham <thomas.ab@samsung.com");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:dwmmc-exynos");
>
thomas.abraham@linaro.org Aug. 28, 2012, 4:48 a.m. UTC | #2
On 27 August 2012 14:28, Jaehoon Chung <jh80.chung@samsung.com> wrote:
> Hi Thomas,
>
>> +     gpio = of_get_named_gpio(slot_np, "wp-gpios", 0);
>> +     if (gpio_is_valid(gpio)) {
>> +             if (devm_gpio_request(host->dev, gpio, "dw-mci-wp"))
>> +                     dev_info(host->dev, "gpio [%d] request failed\n",
>> +                                             gpio);
>> +     } else {
>> +             dev_info(host->dev, "wp gpio not available");
>> +             host->pdata->quirks |= DW_MCI_QUIRK_NO_WRITE_PROTECT;
>> +     }
>> +
>> +     if (host->pdata->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)
>> +             return 0;
>> +
>> +     gpio = of_get_named_gpio(slot_np, "samsung,cd-pinmux-gpio", 0);
>> +     if (gpio_is_valid(gpio)) {
>> +             if (devm_gpio_request(host->dev, gpio, "dw-mci-cd"))
> I'm not sure, but i saw mmc_gpio_request_cd() into drivers/mmc/core/slot-gpio.c.
> Can we use this? i think we can use them.
> Just my opinion.

Thanks for letting me know about this, I was not aware of this.
Looking into this code, it is usable for controllers that use a gpio
(specified using cd-gpios property) as card-detect line. As you know,
the dw-mmc driver does not support this feature yet. In case of
exynos, the card-detect pin of the mmc slot is connected to the
card-detect pad of the dw-mmc controller using pinmux, which is not
considered as a gpio. Hence, mmc_gpio_request_cd() is not applicable
in this case.

Thanks,
Thomas.


>
> Best Regards,
> Jaehoon Chung
>> +                     dev_err(host->dev, "gpio [%d] request failed\n", gpio);
>> +     } else {
>> +             dev_info(host->dev, "cd gpio not available");
>> +     }
>> +
>> +     return 0;
>> +}
>> +
>> +/* Exynos5250 controller specific capabilities */
>> +static unsigned long exynos5250_dwmmc_caps[4] = {
>> +     MMC_CAP_UHS_DDR50 | MMC_CAP_1_8V_DDR |
>> +             MMC_CAP_8_BIT_DATA | MMC_CAP_CMD23,
>> +     MMC_CAP_CMD23,
>> +     MMC_CAP_CMD23,
>> +     MMC_CAP_CMD23,
>> +};
>> +
>> +static struct dw_mci_drv_data exynos5250_drv_data = {
>> +     .caps                   = exynos5250_dwmmc_caps,
>> +     .init                   = dw_mci_exynos_priv_init,
>> +     .prepare_command        = dw_mci_exynos_prepare_command,
>> +     .set_ios                = dw_mci_exynos_set_ios,
>> +     .parse_dt               = dw_mci_exynos_parse_dt,
>> +     .setup_bus              = dw_mci_exynos_setup_bus,
>> +};
>> +
>> +static const struct of_device_id dw_mci_exynos_match[] = {
>> +     { .compatible = "samsung,exynos5250-dw-mshc",
>> +                     .data = (void *)&exynos5250_drv_data, },
>> +     {},
>> +};
>> +MODULE_DEVICE_TABLE(of, dw_mci_pltfm_match);
>> +
>> +int dw_mci_exynos_probe(struct platform_device *pdev)
>> +{
>> +     struct dw_mci_drv_data *drv_data;
>> +     const struct of_device_id *match;
>> +
>> +     match = of_match_node(dw_mci_exynos_match, pdev->dev.of_node);
>> +     drv_data = match->data;
>> +     return dw_mci_pltfm_register(pdev, drv_data);
>> +}
>> +
>> +static struct platform_driver dw_mci_exynos_pltfm_driver = {
>> +     .probe          = dw_mci_exynos_probe,
>> +     .remove         = __exit_p(dw_mci_pltfm_remove),
>> +     .driver         = {
>> +             .name           = "dwmmc_exynos",
>> +             .of_match_table = of_match_ptr(dw_mci_exynos_match),
>> +             .pm             = &dw_mci_pltfm_pmops,
>> +     },
>> +};
>> +
>> +module_platform_driver(dw_mci_exynos_pltfm_driver);
>> +
>> +MODULE_DESCRIPTION("Samsung Specific DW-MSHC Driver Extension");
>> +MODULE_AUTHOR("Thomas Abraham <thomas.ab@samsung.com");
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_ALIAS("platform:dwmmc-exynos");
>>
>
Jaehoon Chung Aug. 28, 2012, 4:55 a.m. UTC | #3
Hi Thomas,

On 08/28/2012 01:48 PM, Thomas Abraham wrote:
> On 27 August 2012 14:28, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>> Hi Thomas,
>>
>>> +     gpio = of_get_named_gpio(slot_np, "wp-gpios", 0);
>>> +     if (gpio_is_valid(gpio)) {
>>> +             if (devm_gpio_request(host->dev, gpio, "dw-mci-wp"))
>>> +                     dev_info(host->dev, "gpio [%d] request failed\n",
>>> +                                             gpio);
>>> +     } else {
>>> +             dev_info(host->dev, "wp gpio not available");
>>> +             host->pdata->quirks |= DW_MCI_QUIRK_NO_WRITE_PROTECT;
>>> +     }
>>> +
>>> +     if (host->pdata->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)
>>> +             return 0;
>>> +
>>> +     gpio = of_get_named_gpio(slot_np, "samsung,cd-pinmux-gpio", 0);
>>> +     if (gpio_is_valid(gpio)) {
>>> +             if (devm_gpio_request(host->dev, gpio, "dw-mci-cd"))
>> I'm not sure, but i saw mmc_gpio_request_cd() into drivers/mmc/core/slot-gpio.c.
>> Can we use this? i think we can use them.
>> Just my opinion.
> 
> Thanks for letting me know about this, I was not aware of this.
> Looking into this code, it is usable for controllers that use a gpio
> (specified using cd-gpios property) as card-detect line. As you know,
> the dw-mmc driver does not support this feature yet. In case of
> exynos, the card-detect pin of the mmc slot is connected to the
> card-detect pad of the dw-mmc controller using pinmux, which is not
> considered as a gpio. Hence, mmc_gpio_request_cd() is not applicable
> in this case.
But In case of external card-detect-pin, we can use the mmc_gpio_request_cd().

Best Regards,
Jaehoon Chung
> 
> Thanks,
> Thomas.
> 
> 
>>
>> Best Regards,
>> Jaehoon Chung
>>> +                     dev_err(host->dev, "gpio [%d] request failed\n", gpio);
>>> +     } else {
>>> +             dev_info(host->dev, "cd gpio not available");
>>> +     }
>>> +
>>> +     return 0;
>>> +}
>>> +
>>> +/* Exynos5250 controller specific capabilities */
>>> +static unsigned long exynos5250_dwmmc_caps[4] = {
>>> +     MMC_CAP_UHS_DDR50 | MMC_CAP_1_8V_DDR |
>>> +             MMC_CAP_8_BIT_DATA | MMC_CAP_CMD23,
>>> +     MMC_CAP_CMD23,
>>> +     MMC_CAP_CMD23,
>>> +     MMC_CAP_CMD23,
>>> +};
>>> +
>>> +static struct dw_mci_drv_data exynos5250_drv_data = {
>>> +     .caps                   = exynos5250_dwmmc_caps,
>>> +     .init                   = dw_mci_exynos_priv_init,
>>> +     .prepare_command        = dw_mci_exynos_prepare_command,
>>> +     .set_ios                = dw_mci_exynos_set_ios,
>>> +     .parse_dt               = dw_mci_exynos_parse_dt,
>>> +     .setup_bus              = dw_mci_exynos_setup_bus,
>>> +};
>>> +
>>> +static const struct of_device_id dw_mci_exynos_match[] = {
>>> +     { .compatible = "samsung,exynos5250-dw-mshc",
>>> +                     .data = (void *)&exynos5250_drv_data, },
>>> +     {},
>>> +};
>>> +MODULE_DEVICE_TABLE(of, dw_mci_pltfm_match);
>>> +
>>> +int dw_mci_exynos_probe(struct platform_device *pdev)
>>> +{
>>> +     struct dw_mci_drv_data *drv_data;
>>> +     const struct of_device_id *match;
>>> +
>>> +     match = of_match_node(dw_mci_exynos_match, pdev->dev.of_node);
>>> +     drv_data = match->data;
>>> +     return dw_mci_pltfm_register(pdev, drv_data);
>>> +}
>>> +
>>> +static struct platform_driver dw_mci_exynos_pltfm_driver = {
>>> +     .probe          = dw_mci_exynos_probe,
>>> +     .remove         = __exit_p(dw_mci_pltfm_remove),
>>> +     .driver         = {
>>> +             .name           = "dwmmc_exynos",
>>> +             .of_match_table = of_match_ptr(dw_mci_exynos_match),
>>> +             .pm             = &dw_mci_pltfm_pmops,
>>> +     },
>>> +};
>>> +
>>> +module_platform_driver(dw_mci_exynos_pltfm_driver);
>>> +
>>> +MODULE_DESCRIPTION("Samsung Specific DW-MSHC Driver Extension");
>>> +MODULE_AUTHOR("Thomas Abraham <thomas.ab@samsung.com");
>>> +MODULE_LICENSE("GPL v2");
>>> +MODULE_ALIAS("platform:dwmmc-exynos");
>>>
>>
>
thomas.abraham@linaro.org Aug. 28, 2012, 5:10 a.m. UTC | #4
On 28 August 2012 10:25, Jaehoon Chung <jh80.chung@samsung.com> wrote:
> Hi Thomas,
>
> On 08/28/2012 01:48 PM, Thomas Abraham wrote:
>> On 27 August 2012 14:28, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>>> Hi Thomas,
>>>
>>>> +     gpio = of_get_named_gpio(slot_np, "wp-gpios", 0);
>>>> +     if (gpio_is_valid(gpio)) {
>>>> +             if (devm_gpio_request(host->dev, gpio, "dw-mci-wp"))
>>>> +                     dev_info(host->dev, "gpio [%d] request failed\n",
>>>> +                                             gpio);
>>>> +     } else {
>>>> +             dev_info(host->dev, "wp gpio not available");
>>>> +             host->pdata->quirks |= DW_MCI_QUIRK_NO_WRITE_PROTECT;
>>>> +     }
>>>> +
>>>> +     if (host->pdata->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)
>>>> +             return 0;
>>>> +
>>>> +     gpio = of_get_named_gpio(slot_np, "samsung,cd-pinmux-gpio", 0);
>>>> +     if (gpio_is_valid(gpio)) {
>>>> +             if (devm_gpio_request(host->dev, gpio, "dw-mci-cd"))
>>> I'm not sure, but i saw mmc_gpio_request_cd() into drivers/mmc/core/slot-gpio.c.
>>> Can we use this? i think we can use them.
>>> Just my opinion.
>>
>> Thanks for letting me know about this, I was not aware of this.
>> Looking into this code, it is usable for controllers that use a gpio
>> (specified using cd-gpios property) as card-detect line. As you know,
>> the dw-mmc driver does not support this feature yet. In case of
>> exynos, the card-detect pin of the mmc slot is connected to the
>> card-detect pad of the dw-mmc controller using pinmux, which is not
>> considered as a gpio. Hence, mmc_gpio_request_cd() is not applicable
>> in this case.
> But In case of external card-detect-pin, we can use the mmc_gpio_request_cd().

Yes, we can use. But the current dw-mmc controller driver does not
support this feature yet. The existing driver considers that (a)
card-detect line is connected to the card-detect pad of the controller
or (b) it is broken. For Exynos5250, it is case (a). There is no
support for using a gpio as an card-detect line.

Thanks,
Thomas.
thomas.abraham@linaro.org Aug. 28, 2012, 5:10 a.m. UTC | #5
On 28 August 2012 10:40, Thomas Abraham <thomas.abraham@linaro.org> wrote:
> On 28 August 2012 10:25, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>> Hi Thomas,
>>
>> On 08/28/2012 01:48 PM, Thomas Abraham wrote:
>>> On 27 August 2012 14:28, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>>>> Hi Thomas,
>>>>
>>>>> +     gpio = of_get_named_gpio(slot_np, "wp-gpios", 0);
>>>>> +     if (gpio_is_valid(gpio)) {
>>>>> +             if (devm_gpio_request(host->dev, gpio, "dw-mci-wp"))
>>>>> +                     dev_info(host->dev, "gpio [%d] request failed\n",
>>>>> +                                             gpio);
>>>>> +     } else {
>>>>> +             dev_info(host->dev, "wp gpio not available");
>>>>> +             host->pdata->quirks |= DW_MCI_QUIRK_NO_WRITE_PROTECT;
>>>>> +     }
>>>>> +
>>>>> +     if (host->pdata->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)
>>>>> +             return 0;
>>>>> +
>>>>> +     gpio = of_get_named_gpio(slot_np, "samsung,cd-pinmux-gpio", 0);
>>>>> +     if (gpio_is_valid(gpio)) {
>>>>> +             if (devm_gpio_request(host->dev, gpio, "dw-mci-cd"))
>>>> I'm not sure, but i saw mmc_gpio_request_cd() into drivers/mmc/core/slot-gpio.c.
>>>> Can we use this? i think we can use them.
>>>> Just my opinion.
>>>
>>> Thanks for letting me know about this, I was not aware of this.
>>> Looking into this code, it is usable for controllers that use a gpio
>>> (specified using cd-gpios property) as card-detect line. As you know,
>>> the dw-mmc driver does not support this feature yet. In case of
>>> exynos, the card-detect pin of the mmc slot is connected to the
>>> card-detect pad of the dw-mmc controller using pinmux, which is not
>>> considered as a gpio. Hence, mmc_gpio_request_cd() is not applicable
>>> in this case.
>> But In case of external card-detect-pin, we can use the mmc_gpio_request_cd().
>
> Yes, we can use. But the current dw-mmc controller driver does not
> support this feature yet. The existing driver considers that (a)
> card-detect line is connected to the card-detect pad of the controller
> or (b) it is broken. For Exynos5250, it is case (a). There is no

Sorry, I meant smdk5250, not Exynos5250.

> support for using a gpio as an card-detect line.
>
> Thanks,
> Thomas.
Jaehoon Chung Aug. 28, 2012, 5:16 a.m. UTC | #6
On 08/28/2012 02:10 PM, Thomas Abraham wrote:
> On 28 August 2012 10:40, Thomas Abraham <thomas.abraham@linaro.org> wrote:
>> On 28 August 2012 10:25, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>>> Hi Thomas,
>>>
>>> On 08/28/2012 01:48 PM, Thomas Abraham wrote:
>>>> On 27 August 2012 14:28, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>>>>> Hi Thomas,
>>>>>
>>>>>> +     gpio = of_get_named_gpio(slot_np, "wp-gpios", 0);
>>>>>> +     if (gpio_is_valid(gpio)) {
>>>>>> +             if (devm_gpio_request(host->dev, gpio, "dw-mci-wp"))
>>>>>> +                     dev_info(host->dev, "gpio [%d] request failed\n",
>>>>>> +                                             gpio);
>>>>>> +     } else {
>>>>>> +             dev_info(host->dev, "wp gpio not available");
>>>>>> +             host->pdata->quirks |= DW_MCI_QUIRK_NO_WRITE_PROTECT;
>>>>>> +     }
>>>>>> +
>>>>>> +     if (host->pdata->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)
>>>>>> +             return 0;
>>>>>> +
>>>>>> +     gpio = of_get_named_gpio(slot_np, "samsung,cd-pinmux-gpio", 0);
>>>>>> +     if (gpio_is_valid(gpio)) {
>>>>>> +             if (devm_gpio_request(host->dev, gpio, "dw-mci-cd"))
>>>>> I'm not sure, but i saw mmc_gpio_request_cd() into drivers/mmc/core/slot-gpio.c.
>>>>> Can we use this? i think we can use them.
>>>>> Just my opinion.
>>>>
>>>> Thanks for letting me know about this, I was not aware of this.
>>>> Looking into this code, it is usable for controllers that use a gpio
>>>> (specified using cd-gpios property) as card-detect line. As you know,
>>>> the dw-mmc driver does not support this feature yet. In case of
>>>> exynos, the card-detect pin of the mmc slot is connected to the
>>>> card-detect pad of the dw-mmc controller using pinmux, which is not
>>>> considered as a gpio. Hence, mmc_gpio_request_cd() is not applicable
>>>> in this case.
>>> But In case of external card-detect-pin, we can use the mmc_gpio_request_cd().
>>
>> Yes, we can use. But the current dw-mmc controller driver does not
>> support this feature yet. The existing driver considers that (a)
>> card-detect line is connected to the card-detect pad of the controller
>> or (b) it is broken. For Exynos5250, it is case (a). There is no
> 
> Sorry, I meant smdk5250, not Exynos5250.
Already i tested with my exynos5 board.
If you want, i will share the patch.

Best Regards,
Jaehoon Chung
> 
>> support for using a gpio as an card-detect line.
>>
>> Thanks,
>> Thomas.
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>
thomas.abraham@linaro.org Aug. 28, 2012, 5:20 a.m. UTC | #7
On 28 August 2012 10:46, Jaehoon Chung <jh80.chung@samsung.com> wrote:
> On 08/28/2012 02:10 PM, Thomas Abraham wrote:
>> On 28 August 2012 10:40, Thomas Abraham <thomas.abraham@linaro.org> wrote:
>>> On 28 August 2012 10:25, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>>>> Hi Thomas,
>>>>
>>>> On 08/28/2012 01:48 PM, Thomas Abraham wrote:
>>>>> On 27 August 2012 14:28, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>>>>>> Hi Thomas,
>>>>>>
>>>>>>> +     gpio = of_get_named_gpio(slot_np, "wp-gpios", 0);
>>>>>>> +     if (gpio_is_valid(gpio)) {
>>>>>>> +             if (devm_gpio_request(host->dev, gpio, "dw-mci-wp"))
>>>>>>> +                     dev_info(host->dev, "gpio [%d] request failed\n",
>>>>>>> +                                             gpio);
>>>>>>> +     } else {
>>>>>>> +             dev_info(host->dev, "wp gpio not available");
>>>>>>> +             host->pdata->quirks |= DW_MCI_QUIRK_NO_WRITE_PROTECT;
>>>>>>> +     }
>>>>>>> +
>>>>>>> +     if (host->pdata->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)
>>>>>>> +             return 0;
>>>>>>> +
>>>>>>> +     gpio = of_get_named_gpio(slot_np, "samsung,cd-pinmux-gpio", 0);
>>>>>>> +     if (gpio_is_valid(gpio)) {
>>>>>>> +             if (devm_gpio_request(host->dev, gpio, "dw-mci-cd"))
>>>>>> I'm not sure, but i saw mmc_gpio_request_cd() into drivers/mmc/core/slot-gpio.c.
>>>>>> Can we use this? i think we can use them.
>>>>>> Just my opinion.
>>>>>
>>>>> Thanks for letting me know about this, I was not aware of this.
>>>>> Looking into this code, it is usable for controllers that use a gpio
>>>>> (specified using cd-gpios property) as card-detect line. As you know,
>>>>> the dw-mmc driver does not support this feature yet. In case of
>>>>> exynos, the card-detect pin of the mmc slot is connected to the
>>>>> card-detect pad of the dw-mmc controller using pinmux, which is not
>>>>> considered as a gpio. Hence, mmc_gpio_request_cd() is not applicable
>>>>> in this case.
>>>> But In case of external card-detect-pin, we can use the mmc_gpio_request_cd().
>>>
>>> Yes, we can use. But the current dw-mmc controller driver does not
>>> support this feature yet. The existing driver considers that (a)
>>> card-detect line is connected to the card-detect pad of the controller
>>> or (b) it is broken. For Exynos5250, it is case (a). There is no
>>
>> Sorry, I meant smdk5250, not Exynos5250.
> Already i tested with my exynos5 board.
> If you want, i will share the patch.

But did you use "samsung,cd-pinmux-gpio" binding or "cd-gpios" binding
for specifying the card-detect line. I think, for your board, you have
to use "cd-gpios". But this patch series does not add support for
"cd-gpios".

Sure, I will like to have a look at your patch and understand more.

Thanks,
Thomas.
Seungwon Jeon Aug. 28, 2012, 7:06 a.m. UTC | #8
Hi Thomas,

Thank you for your effort.
Some reviews seems like to be omitted. Please check more.

On Sunday, August 26, 2012 Thomas Abraham <thomas.abraham@linaro.org> wrote:
> Samsung Exynos SoC's extend the dw-mshc controller for additional clock and bus
> control. Add support for these extensions and include provide device tree based
> discovery suppory as well.
> 
> Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
> ---
>  .../devicetree/bindings/mmc/exynos-dw-mshc.txt     |   79 +++++++
>  drivers/mmc/host/Kconfig                           |    9 +
>  drivers/mmc/host/Makefile                          |    3 +-
>  drivers/mmc/host/dw_mmc-exynos.c                   |  247 ++++++++++++++++++++
>  4 files changed, 337 insertions(+), 1 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
>  create mode 100644 drivers/mmc/host/dw_mmc-exynos.c
> 
> diff --git a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
> b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
> new file mode 100644
> index 0000000..a7a6039
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
> @@ -0,0 +1,79 @@
> +* Samsung Exynos specific extensions to the Synopsis Designware Mobile
> +  Storage Host Controller
> +
> +The Synopsis designware mobile storage host controller is used to interface
> +a SoC with storage medium such as eMMC or SD/MMC cards. This file documents
> +differences between the core Synopsis dw mshc controller properties described
> +by synposis-dw-mshc.txt and the properties used by the Samsung Exynos specific
> +extensions to the Synopsis Designware Mobile Storage Host Controller.
> +
> +Required Properties:
> +
> +* compatible: should be
> +	- "samsung,exynos4210-dw-mshc": for controllers with Samsung Exynos4210
> +	  specific extentions.
> +	- "samsung,exynos4412-dw-mshc": for controllers with Samsung Exynos4412
> +	  specific extentions.
> +	- "samsung,exynos5250-dw-mshc": for controllers with Samsung Exynos5250
> +	  specific extentions.
> +
> +Optional Controller Properties:
> +
> +* samsung,dw-mshc-sdr-timing: Specifies the value of CUI clock divider, CIU
> +  clock phase shift value in transmit mode and CIU clock phase shift value in
> +  receive mode for single data rate mode operation. Refer notes of the valid
> +  values below.
> +
> +* samsung,dw-mshc-ddr-timing: Specifies the value of CUI clock divider, CIU
> +  clock phase shift value in transmit mode and CIU clock phase shift value in
> +  receive mode for double data rate mode operation. Refer notes of the valid
> +  values below. The order of the cells should be
> +
> +    - First Cell: 	CIU clock divider value (applicable only for Exynos5
> +			SoC's, should be zero for Exynos4 SoC's)
> +    - Second Cell:	CIU clock phase shift value for tx mode.
> +    - Third Cell:	CIU clock phase shift value for rx mode.
> +
> +  Valid values for SDR and DDR CIU clock timing for Exynos5250:
> +
> +    - valid values for CIU clock divider, tx phase shift and rx phase shift
> +      is 0 to 7.
> +
> +    - When CIU clock divider value is set to 3, all possible 8 phase shift
> +      values can be used.
> +
> +    - If CIU clock divider value is 0 (that is divide by 1), both tx and rx
> +      phase shift clocks should be 0.
> +
> +Example:
> +
> +  The MSHC controller node can be split into two portions, SoC specific and
> +  board specific portions as listed below.
> +
> +	dwmmc0@12200000 {
> +		compatible = "samsung,exynos5250-dw-mshc";
> +		reg = <0x12200000 0x1000>;
> +		interrupts = <0 75 0>;
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +	};
> +
> +	dwmmc0@12200000 {
> +		num-slots = <1>;
> +		supports-highspeed;
> +		broken-cd;
> +		fifo-depth = <0x80>;
> +		card-detect-delay = <200>;
> +		samsung,dw-mshc-sdr-timing = <2 3 3>;
> +		samsung,dw-mshc-ddr-timing = <1 2 3>;
> +
> +		slot@0 {
> +			reg = <0>;
> +			bus-width = <8>;
> +			gpios = <&gpc0 0 2 0 3>, <&gpc0 1 2 0 3>,
> +				<&gpc1 0 2 3 3>, <&gpc1 1 2 3 3>,
> +				<&gpc1 2 2 3 3>, <&gpc1 3 2 3 3>,
> +				<&gpc0 3 2 3 3>, <&gpc0 4 2 3 3>,
> +				<&gpc0 5 2 3 3>, <&gpc0 6 2 3 3>;
> +		};
> +	};
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index aa131b3..70eec88 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -540,6 +540,15 @@ config MMC_DW_PLTFM
> 
>  	  If unsure, say Y.
> 
> +config MMC_DW_EXYNOS
> +	bool "Exynos specific extentions for Synopsys DW Memory Card Interface"
> +	depends on MMC_DW
> +	select MMC_DW_PLTFM
> +	help
> +	  This selects support for Samsung Exynos SoC specific extensions to the
> +	  Synopsys DesignWare Memory Card Interface driver. Select this option
> +	  for platforms based on Exynos4 and Exynos5 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 8922b06..eb17b01 100644
> --- a/drivers/mmc/host/Makefile
> +++ b/drivers/mmc/host/Makefile
> @@ -38,7 +38,8 @@ obj-$(CONFIG_MMC_CB710)		+= cb710-mmc.o
>  obj-$(CONFIG_MMC_VIA_SDMMC)	+= via-sdmmc.o
>  obj-$(CONFIG_SDH_BFIN)		+= bfin_sdh.o
>  obj-$(CONFIG_MMC_DW)		+= dw_mmc.o
> -obj-$(CONFIG_MMC_DW_PLTFM)	+= dw_mmc-pltfm.o
> +obj-$(CONFIG_MMC_DW_PLTFM)	+= dw_mmc-pltfm.o dw_mmc-exynos.o
> +obj-$(CONFIG_MMC_DW_EXYNOS)	+= dw_mmc-exynos.o
>  obj-$(CONFIG_MMC_DW_PCI)	+= dw_mmc-pci.o
>  obj-$(CONFIG_MMC_SH_MMCIF)	+= sh_mmcif.o
>  obj-$(CONFIG_MMC_JZ4740)	+= jz4740_mmc.o
> diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
> new file mode 100644
> index 0000000..beea104
> --- /dev/null
> +++ b/drivers/mmc/host/dw_mmc-exynos.c
> @@ -0,0 +1,247 @@
> +/*
> + * Exynos Specific Extensions for Synopsys DW Multimedia Card Interface driver
> + *
> + * Copyright (C) 2012, Samsung Electronics Co., Ltd.
> + *
> + * 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/platform_device.h>
> +#include <linux/clk.h>
> +#include <linux/mmc/host.h>
> +#include <linux/mmc/dw_mmc.h>
> +#include <linux/of.h>
> +#include <linux/of_gpio.h>
> +
> +#include "dw_mmc.h"
> +#include "dw_mmc-pltfm.h"
> +
> +#define NUM_PINS(x)			(x + 2)
> +
> +#define SDMMC_CLKSEL			0x09C
> +#define SDMMC_CLKSEL_CCLK_SAMPLE(x)	(((x) & 7) << 0)
> +#define SDMMC_CLKSEL_CCLK_DRIVE(x)	(((x) & 7) << 16)
> +#define SDMMC_CLKSEL_CCLK_DIVIDER(x)	(((x) & 7) << 24)
> +#define SDMMC_CLKSEL_GET_DIVRATIO(x)	((((x) >> 24) & 0x7) + 1)
> +#define SDMMC_CLKSEL_GET_DRV_WD2(x)	(((x) >> 16) & 0x3)
> +#define SDMMC_CLKSEL_GET_DRV_WD3(x)	(((x) >> 16) & 0x7)
> +#define SDMMC_CLKSEL_TIMING(x, y, z)	(SDMMC_CLKSEL_CCLK_SAMPLE(x) |	\
> +					SDMMC_CLKSEL_CCLK_DRIVE(y) |	\
> +					SDMMC_CLKSEL_CCLK_DIVIDER(z))
> +
> +#define SDMMC_CMD_USE_HOLD_REG		BIT(29)
> +
> +#define DW_MCI_DEF_SDR_TIMING		0x03030002
> +#define DW_MCI_DEF_DDR_TIMING		0x03020001
> +
> +/* Variations in Exynos specific dw-mshc controller */
> +enum dw_mci_exynos_type {
> +	DW_MCI_TYPE_EXYNOS4210,
> +	DW_MCI_TYPE_EXYNOS4412,
> +	DW_MCI_TYPE_EXYNOS5250,
> +};
> +
> +/* Exynos implementation specific driver private data */
> +struct dw_mci_exynos_priv_data {
> +	enum dw_mci_exynos_type		ctrl_type;
> +	u32				sdr_timing;
> +	u32				ddr_timing;
> +};
> +
> +static struct dw_mci_exynos_compatible {
> +	char				*compatible;
> +	enum dw_mci_exynos_type		ctrl_type;
> +} exynos_compat[] = {
> +	{
> +		.compatible	= "samsung,exynos4210-dw-mshc",
> +		.ctrl_type	= DW_MCI_TYPE_EXYNOS4210,
> +	}, {
> +		.compatible	= "samsung,exynos4210-dw-mshc",
typo? exynos4412-dw-mshc is expected.

> +		.ctrl_type	= DW_MCI_TYPE_EXYNOS4412,
> +	}, {
> +		.compatible	= "samsung,exynos5250-dw-mshc",
> +		.ctrl_type	= DW_MCI_TYPE_EXYNOS5250,
> +	},
> +};
> +
> +static int dw_mci_exynos_priv_init(struct dw_mci *host)
> +{
> +	struct dw_mci_exynos_priv_data *priv;
> +	int idx;
> +
> +	priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv) {
> +		dev_err(host->dev, "mem alloc failed for private data\n");
> +		return -ENOMEM;
> +	}
> +
> +	for (idx = 0; idx < ARRAY_SIZE(exynos_compat); idx++) {
> +		if (of_device_is_compatible(host->dev->of_node,
> +					exynos_compat[idx].compatible))
> +			priv->ctrl_type = exynos_compat[idx].ctrl_type;
> +	}
> +
> +	host->priv = priv;
> +	return 0;
> +}
> +
> +static void dw_mci_exynos_prepare_command(struct dw_mci *host, u32 *cmdr)
> +{
> +	struct dw_mci_exynos_priv_data *priv = host->priv;
> +	u8 drv;
> +
> +	/*
> +	 * Exynos4412 and Exynos5250 extends the use of CMD register with the
> +	 * use of bit 29 (which is reserved on standard MSHC controllers) for
> +	 * optionally bypassing the HOLD register for command and data. The
> +	 * HOLD register should be bypassed in case there is no phase shift
> +	 * applied on CMD/DATA that is sent to the card.
> +	 */
> +	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4412)
> +		drv = SDMMC_CLKSEL_GET_DRV_WD2(mci_readl(host, CLKSEL));
As it  has been mentioned previously,  only exynos4210 uses 2-bit.
So SDMMC_CLKSEL_GET_DRV_WD3 will be right in exynos4412.

> +	else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS5250)
> +		drv = SDMMC_CLKSEL_GET_DRV_WD3(mci_readl(host, CLKSEL));
> +	else
> +		return;
> +	if (drv)
> +		*cmdr |= SDMMC_CMD_USE_HOLD_REG;
> +}
> +
> +static void dw_mci_exynos_set_ios(struct dw_mci *host, struct mmc_ios *ios)
> +{
> +	struct dw_mci_exynos_priv_data *priv = host->priv;
> +
> +	if (ios->timing == MMC_TIMING_UHS_DDR50)
> +		mci_writel(host, CLKSEL, priv->ddr_timing);
> +	else
> +		mci_writel(host, CLKSEL, priv->sdr_timing);
> +
> +	host->bus_hz = clk_get_rate(host->ciu_clk);
> +	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS5250)
> +		host->bus_hz /= SDMMC_CLKSEL_GET_DIVRATIO(
> +					mci_readl(host, CLKSEL));
bus_hz should be recalculated for exynoxs4 as well.
Could you check the previous mailing?

> +}
> +
> +static int dw_mci_exynos_parse_dt(struct dw_mci *host)
> +{
> +	struct dw_mci_exynos_priv_data *priv = host->priv;
> +	u32 timing[3];
> +
> +	if (of_property_read_u32_array(host->dev->of_node,
> +			"samsung,dw-mshc-sdr-timing", timing, 3))
> +		priv->sdr_timing = DW_MCI_DEF_SDR_TIMING;
> +	else
> +		priv->sdr_timing = SDMMC_CLKSEL_TIMING(timing[0],
> +					timing[1], timing[2]);
> +
> +	if (of_property_read_u32_array(host->dev->of_node,
> +			"samsung,dw-mshc-ddr-timing", timing, 3))
> +		priv->ddr_timing = DW_MCI_DEF_DDR_TIMING;
> +	else
> +		priv->ddr_timing = SDMMC_CLKSEL_TIMING(timing[0],
> +					timing[1], timing[2]);
> +	return 0;
DW_MCI_DEF_SDR_TIMING and DW_MCI_DEF_DDR_TIMING are board-specific timing values.
So, these values can't be used commonly. It has been already discussed.
If this property is empty, returning error with message will be fine.
Currently just 0 is always returned.

Thanks,
Seungwon Jeon

> +}
> +
> +static int dw_mci_exynos_setup_bus(struct dw_mci *host,
> +				struct device_node *slot_np, u8 bus_width)
> +{
> +	int idx, gpio, ret;
> +
> +	if (!slot_np)
> +		return -EINVAL;
> +
> +	/* cmd + clock + bus-width pins */
> +	for (idx = 0; idx < NUM_PINS(bus_width); idx++) {
> +		gpio = of_get_gpio(slot_np, idx);
> +		if (!gpio_is_valid(gpio)) {
> +			dev_err(host->dev, "invalid gpio: %d\n", gpio);
> +			return -EINVAL;
> +		}
> +
> +		ret = devm_gpio_request(host->dev, gpio, "dw-mci-bus");
> +		if (ret) {
> +			dev_err(host->dev, "gpio [%d] request failed\n", gpio);
> +			return -EBUSY;
> +		}
> +	}
> +
> +	gpio = of_get_named_gpio(slot_np, "wp-gpios", 0);
> +	if (gpio_is_valid(gpio)) {
> +		if (devm_gpio_request(host->dev, gpio, "dw-mci-wp"))
> +			dev_info(host->dev, "gpio [%d] request failed\n",
> +						gpio);
> +	} else {
> +		dev_info(host->dev, "wp gpio not available");
> +		host->pdata->quirks |= DW_MCI_QUIRK_NO_WRITE_PROTECT;
> +	}
> +
> +	if (host->pdata->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)
> +		return 0;
> +
> +	gpio = of_get_named_gpio(slot_np, "samsung,cd-pinmux-gpio", 0);
> +	if (gpio_is_valid(gpio)) {
> +		if (devm_gpio_request(host->dev, gpio, "dw-mci-cd"))
> +			dev_err(host->dev, "gpio [%d] request failed\n", gpio);
> +	} else {
> +		dev_info(host->dev, "cd gpio not available");
> +	}
> +
> +	return 0;
> +}
> +
> +/* Exynos5250 controller specific capabilities */
> +static unsigned long exynos5250_dwmmc_caps[4] = {
> +	MMC_CAP_UHS_DDR50 | MMC_CAP_1_8V_DDR |
> +		MMC_CAP_8_BIT_DATA | MMC_CAP_CMD23,
> +	MMC_CAP_CMD23,
> +	MMC_CAP_CMD23,
> +	MMC_CAP_CMD23,
> +};
> +
> +static struct dw_mci_drv_data exynos5250_drv_data = {
> +	.caps			= exynos5250_dwmmc_caps,
> +	.init			= dw_mci_exynos_priv_init,
> +	.prepare_command	= dw_mci_exynos_prepare_command,
> +	.set_ios		= dw_mci_exynos_set_ios,
> +	.parse_dt		= dw_mci_exynos_parse_dt,
> +	.setup_bus		= dw_mci_exynos_setup_bus,
> +};
> +
> +static const struct of_device_id dw_mci_exynos_match[] = {
> +	{ .compatible = "samsung,exynos5250-dw-mshc",
> +			.data = (void *)&exynos5250_drv_data, },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, dw_mci_pltfm_match);
> +
> +int dw_mci_exynos_probe(struct platform_device *pdev)
> +{
> +	struct dw_mci_drv_data *drv_data;
> +	const struct of_device_id *match;
> +
> +	match = of_match_node(dw_mci_exynos_match, pdev->dev.of_node);
> +	drv_data = match->data;
> +	return dw_mci_pltfm_register(pdev, drv_data);
> +}
> +
> +static struct platform_driver dw_mci_exynos_pltfm_driver = {
> +	.probe		= dw_mci_exynos_probe,
> +	.remove		= __exit_p(dw_mci_pltfm_remove),
> +	.driver		= {
> +		.name		= "dwmmc_exynos",
> +		.of_match_table	= of_match_ptr(dw_mci_exynos_match),
> +		.pm		= &dw_mci_pltfm_pmops,
> +	},
> +};
> +
> +module_platform_driver(dw_mci_exynos_pltfm_driver);
> +
> +MODULE_DESCRIPTION("Samsung Specific DW-MSHC Driver Extension");
> +MODULE_AUTHOR("Thomas Abraham <thomas.ab@samsung.com");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:dwmmc-exynos");
> --
> 1.6.6.rc2
thomas.abraham@linaro.org Aug. 28, 2012, 7:42 a.m. UTC | #9
Hi Seungwon,

On 28 August 2012 12:36, Seungwon Jeon <tgih.jun@samsung.com> wrote:
> Hi Thomas,
>
> Thank you for your effort.
> Some reviews seems like to be omitted. Please check more.
>
> On Sunday, August 26, 2012 Thomas Abraham <thomas.abraham@linaro.org> wrote:
>> Samsung Exynos SoC's extend the dw-mshc controller for additional clock and bus
>> control. Add support for these extensions and include provide device tree based
>> discovery suppory as well.

[...]

>> +static struct dw_mci_exynos_compatible {
>> +     char                            *compatible;
>> +     enum dw_mci_exynos_type         ctrl_type;
>> +} exynos_compat[] = {
>> +     {
>> +             .compatible     = "samsung,exynos4210-dw-mshc",
>> +             .ctrl_type      = DW_MCI_TYPE_EXYNOS4210,
>> +     }, {
>> +             .compatible     = "samsung,exynos4210-dw-mshc",
> typo? exynos4412-dw-mshc is expected.

Yes, that was a typo. I will fix it.

[...]

>> +static void dw_mci_exynos_prepare_command(struct dw_mci *host, u32 *cmdr)
>> +{
>> +     struct dw_mci_exynos_priv_data *priv = host->priv;
>> +     u8 drv;
>> +
>> +     /*
>> +      * Exynos4412 and Exynos5250 extends the use of CMD register with the
>> +      * use of bit 29 (which is reserved on standard MSHC controllers) for
>> +      * optionally bypassing the HOLD register for command and data. The
>> +      * HOLD register should be bypassed in case there is no phase shift
>> +      * applied on CMD/DATA that is sent to the card.
>> +      */
>> +     if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4412)
>> +             drv = SDMMC_CLKSEL_GET_DRV_WD2(mci_readl(host, CLKSEL));
> As it  has been mentioned previously,  only exynos4210 uses 2-bit.
> So SDMMC_CLKSEL_GET_DRV_WD3 will be right in exynos4412.

In the Exynos4412 user manual that I referred, the SelClk_Drv and
SelClk_Sample bit fields of the CLKSEL register are 2 bits wide. Could
you please confirm that these two bit-fields are infact 3 bits wide?

>
>> +     else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS5250)
>> +             drv = SDMMC_CLKSEL_GET_DRV_WD3(mci_readl(host, CLKSEL));
>> +     else
>> +             return;
>> +     if (drv)
>> +             *cmdr |= SDMMC_CMD_USE_HOLD_REG;
>> +}
>> +
>> +static void dw_mci_exynos_set_ios(struct dw_mci *host, struct mmc_ios *ios)
>> +{
>> +     struct dw_mci_exynos_priv_data *priv = host->priv;
>> +
>> +     if (ios->timing == MMC_TIMING_UHS_DDR50)
>> +             mci_writel(host, CLKSEL, priv->ddr_timing);
>> +     else
>> +             mci_writel(host, CLKSEL, priv->sdr_timing);
>> +
>> +     host->bus_hz = clk_get_rate(host->ciu_clk);
>> +     if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS5250)
>> +             host->bus_hz /= SDMMC_CLKSEL_GET_DIVRATIO(
>> +                                     mci_readl(host, CLKSEL));
> bus_hz should be recalculated for exynoxs4 as well.
> Could you check the previous mailing?

Exynos4 does not have the additional clock divisor, as in Exynos5250.
Could you please explain why the bus_hz clock should be divided in
Exynos4?

>
>> +}
>> +
>> +static int dw_mci_exynos_parse_dt(struct dw_mci *host)
>> +{
>> +     struct dw_mci_exynos_priv_data *priv = host->priv;
>> +     u32 timing[3];
>> +
>> +     if (of_property_read_u32_array(host->dev->of_node,
>> +                     "samsung,dw-mshc-sdr-timing", timing, 3))
>> +             priv->sdr_timing = DW_MCI_DEF_SDR_TIMING;
>> +     else
>> +             priv->sdr_timing = SDMMC_CLKSEL_TIMING(timing[0],
>> +                                     timing[1], timing[2]);
>> +
>> +     if (of_property_read_u32_array(host->dev->of_node,
>> +                     "samsung,dw-mshc-ddr-timing", timing, 3))
>> +             priv->ddr_timing = DW_MCI_DEF_DDR_TIMING;
>> +     else
>> +             priv->ddr_timing = SDMMC_CLKSEL_TIMING(timing[0],
>> +                                     timing[1], timing[2]);
>> +     return 0;
> DW_MCI_DEF_SDR_TIMING and DW_MCI_DEF_DDR_TIMING are board-specific timing values.
> So, these values can't be used commonly. It has been already discussed.
> If this property is empty, returning error with message will be fine.
> Currently just 0 is always returned.

Yes, you had mentioned this previously. But these are only default
values. In case, a board cannot work with these default values, the
board's dtsi file should provide the correct values by using these
bindings. What is your opinion on this, please let me know.

Thanks for your time reviewing this patch series.

Regards,
Thomas.
Seungwon Jeon Aug. 28, 2012, 10:43 a.m. UTC | #10
On Tuesday, August 28, 2012 Thomas Abraham <thomas.abraham@linaro.org> wrote:
> Hi Seungwon,
> 
> On 28 August 2012 12:36, Seungwon Jeon <tgih.jun@samsung.com> wrote:
> > Hi Thomas,
> >
> > Thank you for your effort.
> > Some reviews seems like to be omitted. Please check more.
> >
> > On Sunday, August 26, 2012 Thomas Abraham <thomas.abraham@linaro.org> wrote:
> >> Samsung Exynos SoC's extend the dw-mshc controller for additional clock and bus
> >> control. Add support for these extensions and include provide device tree based
> >> discovery suppory as well.
> 
> [...]
> 
> >> +static struct dw_mci_exynos_compatible {
> >> +     char                            *compatible;
> >> +     enum dw_mci_exynos_type         ctrl_type;
> >> +} exynos_compat[] = {
> >> +     {
> >> +             .compatible     = "samsung,exynos4210-dw-mshc",
> >> +             .ctrl_type      = DW_MCI_TYPE_EXYNOS4210,
> >> +     }, {
> >> +             .compatible     = "samsung,exynos4210-dw-mshc",
> > typo? exynos4412-dw-mshc is expected.
> 
> Yes, that was a typo. I will fix it.
> 
> [...]
> 
> >> +static void dw_mci_exynos_prepare_command(struct dw_mci *host, u32 *cmdr)
> >> +{
> >> +     struct dw_mci_exynos_priv_data *priv = host->priv;
> >> +     u8 drv;
> >> +
> >> +     /*
> >> +      * Exynos4412 and Exynos5250 extends the use of CMD register with the
> >> +      * use of bit 29 (which is reserved on standard MSHC controllers) for
> >> +      * optionally bypassing the HOLD register for command and data. The
> >> +      * HOLD register should be bypassed in case there is no phase shift
> >> +      * applied on CMD/DATA that is sent to the card.
> >> +      */
> >> +     if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4412)
> >> +             drv = SDMMC_CLKSEL_GET_DRV_WD2(mci_readl(host, CLKSEL));
> > As it  has been mentioned previously,  only exynos4210 uses 2-bit.
> > So SDMMC_CLKSEL_GET_DRV_WD3 will be right in exynos4412.
> 
> In the Exynos4412 user manual that I referred, the SelClk_Drv and
> SelClk_Sample bit fields of the CLKSEL register are 2 bits wide. Could
> you please confirm that these two bit-fields are in fact 3 bits wide?
I think you are referring old manual. 3-bit is right.
I hope you find this.

> 
> >
> >> +     else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS5250)
> >> +             drv = SDMMC_CLKSEL_GET_DRV_WD3(mci_readl(host, CLKSEL));
> >> +     else
> >> +             return;
> >> +     if (drv)
> >> +             *cmdr |= SDMMC_CMD_USE_HOLD_REG;
> >> +}
> >> +
> >> +static void dw_mci_exynos_set_ios(struct dw_mci *host, struct mmc_ios *ios)
> >> +{
> >> +     struct dw_mci_exynos_priv_data *priv = host->priv;
> >> +
> >> +     if (ios->timing == MMC_TIMING_UHS_DDR50)
> >> +             mci_writel(host, CLKSEL, priv->ddr_timing);
> >> +     else
> >> +             mci_writel(host, CLKSEL, priv->sdr_timing);
> >> +
> >> +     host->bus_hz = clk_get_rate(host->ciu_clk);
> >> +     if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS5250)
> >> +             host->bus_hz /= SDMMC_CLKSEL_GET_DIVRATIO(
> >> +                                     mci_readl(host, CLKSEL));
> > bus_hz should be recalculated for exynoxs4 as well.
> > Could you check the previous mailing?
> 
> Exynos4 does not have the additional clock divisor, as in Exynos5250.
> Could you please explain why the bus_hz clock should be divided in
> Exynos4?
Yes, clock divisor is used in Exynos5250.
In case of Exynos4 SoC's, divider value(DIVRATIO) isn't exposed to register.
But  SDCLKIN is divided by fixed divider value internally.
As mentioned previously, divider is used like below.
Exynos4210 : 2
Exynos4X12 : 4

> 
> >
> >> +}
> >> +
> >> +static int dw_mci_exynos_parse_dt(struct dw_mci *host)
> >> +{
> >> +     struct dw_mci_exynos_priv_data *priv = host->priv;
> >> +     u32 timing[3];
> >> +
> >> +     if (of_property_read_u32_array(host->dev->of_node,
> >> +                     "samsung,dw-mshc-sdr-timing", timing, 3))
> >> +             priv->sdr_timing = DW_MCI_DEF_SDR_TIMING;
> >> +     else
> >> +             priv->sdr_timing = SDMMC_CLKSEL_TIMING(timing[0],
> >> +                                     timing[1], timing[2]);
> >> +
> >> +     if (of_property_read_u32_array(host->dev->of_node,
> >> +                     "samsung,dw-mshc-ddr-timing", timing, 3))
> >> +             priv->ddr_timing = DW_MCI_DEF_DDR_TIMING;
> >> +     else
> >> +             priv->ddr_timing = SDMMC_CLKSEL_TIMING(timing[0],
> >> +                                     timing[1], timing[2]);
> >> +     return 0;
> > DW_MCI_DEF_SDR_TIMING and DW_MCI_DEF_DDR_TIMING are board-specific timing values.
> > So, these values can't be used commonly. It has been already discussed.
> > If this property is empty, returning error with message will be fine.
> > Currently just 0 is always returned.
> 
> Yes, you had mentioned this previously. But these are only default
> values. In case, a board cannot work with these default values, the
> board's dtsi file should provide the correct values by using these
> bindings. What is your opinion on this, please let me know.
Is there any basis for these value which you chose?
If these can be acceptable for the most part, we can consider it for default value.
But it depends on host of SOC and target board.

Thanks,
Seungwon Jeon

> 
> Thanks for your time reviewing this patch series.
> 
> Regards,
> Thomas.
thomas.abraham@linaro.org Aug. 28, 2012, 11:35 a.m. UTC | #11
On 28 August 2012 16:13, Seungwon Jeon <tgih.jun@samsung.com> wrote:
> On Tuesday, August 28, 2012 Thomas Abraham <thomas.abraham@linaro.org> wrote:
>> Hi Seungwon,
>>
>> On 28 August 2012 12:36, Seungwon Jeon <tgih.jun@samsung.com> wrote:

[...]

>> >> +     /*
>> >> +      * Exynos4412 and Exynos5250 extends the use of CMD register with the
>> >> +      * use of bit 29 (which is reserved on standard MSHC controllers) for
>> >> +      * optionally bypassing the HOLD register for command and data. The
>> >> +      * HOLD register should be bypassed in case there is no phase shift
>> >> +      * applied on CMD/DATA that is sent to the card.
>> >> +      */
>> >> +     if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4412)
>> >> +             drv = SDMMC_CLKSEL_GET_DRV_WD2(mci_readl(host, CLKSEL));
>> > As it  has been mentioned previously,  only exynos4210 uses 2-bit.
>> > So SDMMC_CLKSEL_GET_DRV_WD3 will be right in exynos4412.
>>
>> In the Exynos4412 user manual that I referred, the SelClk_Drv and
>> SelClk_Sample bit fields of the CLKSEL register are 2 bits wide. Could
>> you please confirm that these two bit-fields are in fact 3 bits wide?
> I think you are referring old manual. 3-bit is right.
> I hope you find this.

Ok. Maybe I have an older manual then. I will change it to 3-bit for 4412.

[...]

>> >> +static void dw_mci_exynos_set_ios(struct dw_mci *host, struct mmc_ios *ios)
>> >> +{
>> >> +     struct dw_mci_exynos_priv_data *priv = host->priv;
>> >> +
>> >> +     if (ios->timing == MMC_TIMING_UHS_DDR50)
>> >> +             mci_writel(host, CLKSEL, priv->ddr_timing);
>> >> +     else
>> >> +             mci_writel(host, CLKSEL, priv->sdr_timing);
>> >> +
>> >> +     host->bus_hz = clk_get_rate(host->ciu_clk);
>> >> +     if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS5250)
>> >> +             host->bus_hz /= SDMMC_CLKSEL_GET_DIVRATIO(
>> >> +                                     mci_readl(host, CLKSEL));
>> > bus_hz should be recalculated for exynoxs4 as well.
>> > Could you check the previous mailing?
>>
>> Exynos4 does not have the additional clock divisor, as in Exynos5250.
>> Could you please explain why the bus_hz clock should be divided in
>> Exynos4?
> Yes, clock divisor is used in Exynos5250.
> In case of Exynos4 SoC's, divider value(DIVRATIO) isn't exposed to register.
> But  SDCLKIN is divided by fixed divider value internally.
> As mentioned previously, divider is used like below.
> Exynos4210 : 2
> Exynos4X12 : 4

Ok. Thanks for the information. I will add divisor support for Exynos4
as well. These patches have not been tested with Exynos4 since I do
not have a Exynos4 based board that uses dw-mmc controller.

[...]

>> > DW_MCI_DEF_SDR_TIMING and DW_MCI_DEF_DDR_TIMING are board-specific timing values.
>> > So, these values can't be used commonly. It has been already discussed.
>> > If this property is empty, returning error with message will be fine.
>> > Currently just 0 is always returned.
>>
>> Yes, you had mentioned this previously. But these are only default
>> values. In case, a board cannot work with these default values, the
>> board's dtsi file should provide the correct values by using these
>> bindings. What is your opinion on this, please let me know.
> Is there any basis for these value which you chose?
> If these can be acceptable for the most part, we can consider it for default value.
> But it depends on host of SOC and target board.

Ok. I will remove the optional value and make this property mandatory.

Thanks,
Thomas.
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
new file mode 100644
index 0000000..a7a6039
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
@@ -0,0 +1,79 @@ 
+* Samsung Exynos specific extensions to the Synopsis Designware Mobile
+  Storage Host Controller
+
+The Synopsis designware mobile storage host controller is used to interface
+a SoC with storage medium such as eMMC or SD/MMC cards. This file documents
+differences between the core Synopsis dw mshc controller properties described
+by synposis-dw-mshc.txt and the properties used by the Samsung Exynos specific
+extensions to the Synopsis Designware Mobile Storage Host Controller.
+
+Required Properties:
+
+* compatible: should be
+	- "samsung,exynos4210-dw-mshc": for controllers with Samsung Exynos4210
+	  specific extentions.
+	- "samsung,exynos4412-dw-mshc": for controllers with Samsung Exynos4412
+	  specific extentions.
+	- "samsung,exynos5250-dw-mshc": for controllers with Samsung Exynos5250
+	  specific extentions.
+
+Optional Controller Properties:
+
+* samsung,dw-mshc-sdr-timing: Specifies the value of CUI clock divider, CIU
+  clock phase shift value in transmit mode and CIU clock phase shift value in
+  receive mode for single data rate mode operation. Refer notes of the valid
+  values below.
+
+* samsung,dw-mshc-ddr-timing: Specifies the value of CUI clock divider, CIU
+  clock phase shift value in transmit mode and CIU clock phase shift value in
+  receive mode for double data rate mode operation. Refer notes of the valid
+  values below. The order of the cells should be
+
+    - First Cell: 	CIU clock divider value (applicable only for Exynos5
+			SoC's, should be zero for Exynos4 SoC's)
+    - Second Cell:	CIU clock phase shift value for tx mode.
+    - Third Cell:	CIU clock phase shift value for rx mode.
+
+  Valid values for SDR and DDR CIU clock timing for Exynos5250:
+
+    - valid values for CIU clock divider, tx phase shift and rx phase shift
+      is 0 to 7.
+
+    - When CIU clock divider value is set to 3, all possible 8 phase shift
+      values can be used.
+
+    - If CIU clock divider value is 0 (that is divide by 1), both tx and rx
+      phase shift clocks should be 0.
+
+Example:
+
+  The MSHC controller node can be split into two portions, SoC specific and
+  board specific portions as listed below.
+
+	dwmmc0@12200000 {
+		compatible = "samsung,exynos5250-dw-mshc";
+		reg = <0x12200000 0x1000>;
+		interrupts = <0 75 0>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+	};
+
+	dwmmc0@12200000 {
+		num-slots = <1>;
+		supports-highspeed;
+		broken-cd;
+		fifo-depth = <0x80>;
+		card-detect-delay = <200>;
+		samsung,dw-mshc-sdr-timing = <2 3 3>;
+		samsung,dw-mshc-ddr-timing = <1 2 3>;
+
+		slot@0 {
+			reg = <0>;
+			bus-width = <8>;
+			gpios = <&gpc0 0 2 0 3>, <&gpc0 1 2 0 3>,
+				<&gpc1 0 2 3 3>, <&gpc1 1 2 3 3>,
+				<&gpc1 2 2 3 3>, <&gpc1 3 2 3 3>,
+				<&gpc0 3 2 3 3>, <&gpc0 4 2 3 3>,
+				<&gpc0 5 2 3 3>, <&gpc0 6 2 3 3>;
+		};
+	};
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index aa131b3..70eec88 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -540,6 +540,15 @@  config MMC_DW_PLTFM
 
 	  If unsure, say Y.
 
+config MMC_DW_EXYNOS
+	bool "Exynos specific extentions for Synopsys DW Memory Card Interface"
+	depends on MMC_DW
+	select MMC_DW_PLTFM
+	help
+	  This selects support for Samsung Exynos SoC specific extensions to the
+	  Synopsys DesignWare Memory Card Interface driver. Select this option
+	  for platforms based on Exynos4 and Exynos5 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 8922b06..eb17b01 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -38,7 +38,8 @@  obj-$(CONFIG_MMC_CB710)		+= cb710-mmc.o
 obj-$(CONFIG_MMC_VIA_SDMMC)	+= via-sdmmc.o
 obj-$(CONFIG_SDH_BFIN)		+= bfin_sdh.o
 obj-$(CONFIG_MMC_DW)		+= dw_mmc.o
-obj-$(CONFIG_MMC_DW_PLTFM)	+= dw_mmc-pltfm.o
+obj-$(CONFIG_MMC_DW_PLTFM)	+= dw_mmc-pltfm.o dw_mmc-exynos.o
+obj-$(CONFIG_MMC_DW_EXYNOS)	+= dw_mmc-exynos.o
 obj-$(CONFIG_MMC_DW_PCI)	+= dw_mmc-pci.o
 obj-$(CONFIG_MMC_SH_MMCIF)	+= sh_mmcif.o
 obj-$(CONFIG_MMC_JZ4740)	+= jz4740_mmc.o
diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
new file mode 100644
index 0000000..beea104
--- /dev/null
+++ b/drivers/mmc/host/dw_mmc-exynos.c
@@ -0,0 +1,247 @@ 
+/*
+ * Exynos Specific Extensions for Synopsys DW Multimedia Card Interface driver
+ *
+ * Copyright (C) 2012, Samsung Electronics Co., Ltd.
+ *
+ * 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/platform_device.h>
+#include <linux/clk.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/dw_mmc.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+
+#include "dw_mmc.h"
+#include "dw_mmc-pltfm.h"
+
+#define NUM_PINS(x)			(x + 2)
+
+#define SDMMC_CLKSEL			0x09C
+#define SDMMC_CLKSEL_CCLK_SAMPLE(x)	(((x) & 7) << 0)
+#define SDMMC_CLKSEL_CCLK_DRIVE(x)	(((x) & 7) << 16)
+#define SDMMC_CLKSEL_CCLK_DIVIDER(x)	(((x) & 7) << 24)
+#define SDMMC_CLKSEL_GET_DIVRATIO(x)	((((x) >> 24) & 0x7) + 1)
+#define SDMMC_CLKSEL_GET_DRV_WD2(x)	(((x) >> 16) & 0x3)
+#define SDMMC_CLKSEL_GET_DRV_WD3(x)	(((x) >> 16) & 0x7)
+#define SDMMC_CLKSEL_TIMING(x, y, z)	(SDMMC_CLKSEL_CCLK_SAMPLE(x) |	\
+					SDMMC_CLKSEL_CCLK_DRIVE(y) |	\
+					SDMMC_CLKSEL_CCLK_DIVIDER(z))
+
+#define SDMMC_CMD_USE_HOLD_REG		BIT(29)
+
+#define DW_MCI_DEF_SDR_TIMING		0x03030002
+#define DW_MCI_DEF_DDR_TIMING		0x03020001
+
+/* Variations in Exynos specific dw-mshc controller */
+enum dw_mci_exynos_type {
+	DW_MCI_TYPE_EXYNOS4210,
+	DW_MCI_TYPE_EXYNOS4412,
+	DW_MCI_TYPE_EXYNOS5250,
+};
+
+/* Exynos implementation specific driver private data */
+struct dw_mci_exynos_priv_data {
+	enum dw_mci_exynos_type		ctrl_type;
+	u32				sdr_timing;
+	u32				ddr_timing;
+};
+
+static struct dw_mci_exynos_compatible {
+	char				*compatible;
+	enum dw_mci_exynos_type		ctrl_type;
+} exynos_compat[] = {
+	{
+		.compatible	= "samsung,exynos4210-dw-mshc",
+		.ctrl_type	= DW_MCI_TYPE_EXYNOS4210,
+	}, {
+		.compatible	= "samsung,exynos4210-dw-mshc",
+		.ctrl_type	= DW_MCI_TYPE_EXYNOS4412,
+	}, {
+		.compatible	= "samsung,exynos5250-dw-mshc",
+		.ctrl_type	= DW_MCI_TYPE_EXYNOS5250,
+	},
+};
+
+static int dw_mci_exynos_priv_init(struct dw_mci *host)
+{
+	struct dw_mci_exynos_priv_data *priv;
+	int idx;
+
+	priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv) {
+		dev_err(host->dev, "mem alloc failed for private data\n");
+		return -ENOMEM;
+	}
+
+	for (idx = 0; idx < ARRAY_SIZE(exynos_compat); idx++) {
+		if (of_device_is_compatible(host->dev->of_node,
+					exynos_compat[idx].compatible))
+			priv->ctrl_type = exynos_compat[idx].ctrl_type;
+	}
+
+	host->priv = priv;
+	return 0;
+}
+
+static void dw_mci_exynos_prepare_command(struct dw_mci *host, u32 *cmdr)
+{
+	struct dw_mci_exynos_priv_data *priv = host->priv;
+	u8 drv;
+
+	/*
+	 * Exynos4412 and Exynos5250 extends the use of CMD register with the
+	 * use of bit 29 (which is reserved on standard MSHC controllers) for
+	 * optionally bypassing the HOLD register for command and data. The
+	 * HOLD register should be bypassed in case there is no phase shift
+	 * applied on CMD/DATA that is sent to the card.
+	 */
+	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4412)
+		drv = SDMMC_CLKSEL_GET_DRV_WD2(mci_readl(host, CLKSEL));
+	else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS5250)
+		drv = SDMMC_CLKSEL_GET_DRV_WD3(mci_readl(host, CLKSEL));
+	else
+		return;
+	if (drv)
+		*cmdr |= SDMMC_CMD_USE_HOLD_REG;
+}
+
+static void dw_mci_exynos_set_ios(struct dw_mci *host, struct mmc_ios *ios)
+{
+	struct dw_mci_exynos_priv_data *priv = host->priv;
+
+	if (ios->timing == MMC_TIMING_UHS_DDR50)
+		mci_writel(host, CLKSEL, priv->ddr_timing);
+	else
+		mci_writel(host, CLKSEL, priv->sdr_timing);
+
+	host->bus_hz = clk_get_rate(host->ciu_clk);
+	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS5250)
+		host->bus_hz /= SDMMC_CLKSEL_GET_DIVRATIO(
+					mci_readl(host, CLKSEL));
+}
+
+static int dw_mci_exynos_parse_dt(struct dw_mci *host)
+{
+	struct dw_mci_exynos_priv_data *priv = host->priv;
+	u32 timing[3];
+
+	if (of_property_read_u32_array(host->dev->of_node,
+			"samsung,dw-mshc-sdr-timing", timing, 3))
+		priv->sdr_timing = DW_MCI_DEF_SDR_TIMING;
+	else
+		priv->sdr_timing = SDMMC_CLKSEL_TIMING(timing[0],
+					timing[1], timing[2]);
+
+	if (of_property_read_u32_array(host->dev->of_node,
+			"samsung,dw-mshc-ddr-timing", timing, 3))
+		priv->ddr_timing = DW_MCI_DEF_DDR_TIMING;
+	else
+		priv->ddr_timing = SDMMC_CLKSEL_TIMING(timing[0],
+					timing[1], timing[2]);
+	return 0;
+}
+
+static int dw_mci_exynos_setup_bus(struct dw_mci *host,
+				struct device_node *slot_np, u8 bus_width)
+{
+	int idx, gpio, ret;
+
+	if (!slot_np)
+		return -EINVAL;
+
+	/* cmd + clock + bus-width pins */
+	for (idx = 0; idx < NUM_PINS(bus_width); idx++) {
+		gpio = of_get_gpio(slot_np, idx);
+		if (!gpio_is_valid(gpio)) {
+			dev_err(host->dev, "invalid gpio: %d\n", gpio);
+			return -EINVAL;
+		}
+
+		ret = devm_gpio_request(host->dev, gpio, "dw-mci-bus");
+		if (ret) {
+			dev_err(host->dev, "gpio [%d] request failed\n", gpio);
+			return -EBUSY;
+		}
+	}
+
+	gpio = of_get_named_gpio(slot_np, "wp-gpios", 0);
+	if (gpio_is_valid(gpio)) {
+		if (devm_gpio_request(host->dev, gpio, "dw-mci-wp"))
+			dev_info(host->dev, "gpio [%d] request failed\n",
+						gpio);
+	} else {
+		dev_info(host->dev, "wp gpio not available");
+		host->pdata->quirks |= DW_MCI_QUIRK_NO_WRITE_PROTECT;
+	}
+
+	if (host->pdata->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)
+		return 0;
+
+	gpio = of_get_named_gpio(slot_np, "samsung,cd-pinmux-gpio", 0);
+	if (gpio_is_valid(gpio)) {
+		if (devm_gpio_request(host->dev, gpio, "dw-mci-cd"))
+			dev_err(host->dev, "gpio [%d] request failed\n", gpio);
+	} else {
+		dev_info(host->dev, "cd gpio not available");
+	}
+
+	return 0;
+}
+
+/* Exynos5250 controller specific capabilities */
+static unsigned long exynos5250_dwmmc_caps[4] = {
+	MMC_CAP_UHS_DDR50 | MMC_CAP_1_8V_DDR |
+		MMC_CAP_8_BIT_DATA | MMC_CAP_CMD23,
+	MMC_CAP_CMD23,
+	MMC_CAP_CMD23,
+	MMC_CAP_CMD23,
+};
+
+static struct dw_mci_drv_data exynos5250_drv_data = {
+	.caps			= exynos5250_dwmmc_caps,
+	.init			= dw_mci_exynos_priv_init,
+	.prepare_command	= dw_mci_exynos_prepare_command,
+	.set_ios		= dw_mci_exynos_set_ios,
+	.parse_dt		= dw_mci_exynos_parse_dt,
+	.setup_bus		= dw_mci_exynos_setup_bus,
+};
+
+static const struct of_device_id dw_mci_exynos_match[] = {
+	{ .compatible = "samsung,exynos5250-dw-mshc",
+			.data = (void *)&exynos5250_drv_data, },
+	{},
+};
+MODULE_DEVICE_TABLE(of, dw_mci_pltfm_match);
+
+int dw_mci_exynos_probe(struct platform_device *pdev)
+{
+	struct dw_mci_drv_data *drv_data;
+	const struct of_device_id *match;
+
+	match = of_match_node(dw_mci_exynos_match, pdev->dev.of_node);
+	drv_data = match->data;
+	return dw_mci_pltfm_register(pdev, drv_data);
+}
+
+static struct platform_driver dw_mci_exynos_pltfm_driver = {
+	.probe		= dw_mci_exynos_probe,
+	.remove		= __exit_p(dw_mci_pltfm_remove),
+	.driver		= {
+		.name		= "dwmmc_exynos",
+		.of_match_table	= of_match_ptr(dw_mci_exynos_match),
+		.pm		= &dw_mci_pltfm_pmops,
+	},
+};
+
+module_platform_driver(dw_mci_exynos_pltfm_driver);
+
+MODULE_DESCRIPTION("Samsung Specific DW-MSHC Driver Extension");
+MODULE_AUTHOR("Thomas Abraham <thomas.ab@samsung.com");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:dwmmc-exynos");