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Re: [PATCH v5 02/11] phy: exynos-ufs: add UFS PHY driver for EXYNOS SoC

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  Re: [PATCH v5 02/11] phy: exynos-ufs: add UFS PHY driver for EXYNOS SoC Alim Akhtar <alim.akhtar@gmail.com> - 2017-02-22 20:00 +0100
    Re: [PATCH v5 02/11] phy: exynos-ufs: add UFS PHY driver for EXYNOS  SoC Kishon Vijay Abraham I <kishon@ti.com> - 2017-02-27 06:30 +0100
      Re: [PATCH v5 02/11] phy: exynos-ufs: add UFS PHY driver for EXYNOS SoC Alim Akhtar <alim.akhtar@samsung.com> - 2017-02-27 15:20 +0100
        Re: [PATCH v5 02/11] phy: exynos-ufs: add UFS PHY driver for EXYNOS SoC Alim Akhtar <alim.akhtar@samsung.com> - 2017-02-28 09:30 +0100

#1586417 — Re: [PATCH v5 02/11] phy: exynos-ufs: add UFS PHY driver for EXYNOS SoC

On Fri, Feb 3, 2017 at 2:49 PM, Alim Akhtar <alim.akhtar@samsung.com> wrote:
> Hi Kishon,
>
>
> On 11/19/2015 07:09 PM, Kishon Vijay Abraham I wrote:
>>
>> Hi,
>>
>> On Tuesday 17 November 2015 01:41 PM, Alim Akhtar wrote:
>>>
>>> Hi
>>> Thanks again for looking into this.
>>>
>>> On 11/17/2015 11:46 AM, Kishon Vijay Abraham I wrote:
>>>>
>>>> Hi,
>>>>
>>>> On Monday 09 November 2015 10:56 AM, Alim Akhtar wrote:
>>>>>
>>>>> From: Seungwon Jeon <essuuj@gmail.com>
>>>>>
>>>>> This patch introduces Exynos UFS PHY driver. This driver
>>>>> supports to deal with phy calibration and power control
>>>>> according to UFS host driver's behavior.
>>>>>
>>>>> Signed-off-by: Seungwon Jeon <essuuj@gmail.com>
>>>>> Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
>>>>> Cc: Kishon Vijay Abraham I <kishon@ti.com>
>>>>> ---
>>>>>   drivers/phy/Kconfig                |    7 ++
>>>>>   drivers/phy/Makefile               |    1 +
>>>>>   drivers/phy/phy-exynos-ufs.c       |  241
>>>>> ++++++++++++++++++++++++++++++++++++
>>>>>   drivers/phy/phy-exynos-ufs.h       |   85 +++++++++++++
>>>>>   drivers/phy/phy-exynos7-ufs.h      |   89 +++++++++++++
>>>>>   include/linux/phy/phy-exynos-ufs.h |   85 +++++++++++++
>>>>>   6 files changed, 508 insertions(+)
>>>>>   create mode 100644 drivers/phy/phy-exynos-ufs.c
>>>>>   create mode 100644 drivers/phy/phy-exynos-ufs.h
>>>>>   create mode 100644 drivers/phy/phy-exynos7-ufs.h
>>>>>   create mode 100644 include/linux/phy/phy-exynos-ufs.h
>>>>>
>>>>> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
>>>>> index 7eb5859dd035..7d38a92e0297 100644
>>>>> --- a/drivers/phy/Kconfig
>>>>> +++ b/drivers/phy/Kconfig
>>>>> @@ -389,4 +389,11 @@ config PHY_CYGNUS_PCIE
>>>>>         Enable this to support the Broadcom Cygnus PCIe PHY.
>>>>>         If unsure, say N.
>>>>>
>>>>> +config PHY_EXYNOS_UFS
>>>>> +    tristate "EXYNOS SoC series UFS PHY driver"
>>>>> +    depends on OF && ARCH_EXYNOS || COMPILE_TEST
>>>>> +    select GENERIC_PHY
>>>>> +    help
>>>>> +      Support for UFS PHY on Samsung EXYNOS chipsets.
>>>>> +
>>>>>   endmenu
>>>>> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
>>>>> index 075db1a81aa5..9bec4d1a89e1 100644
>>>>> --- a/drivers/phy/Makefile
>>>>> +++ b/drivers/phy/Makefile
>>>>> @@ -10,6 +10,7 @@ obj-$(CONFIG_ARMADA375_USBCLUSTER_PHY)    +=
>>>>> phy-armada375-usb2.o
>>>>>   obj-$(CONFIG_BCM_KONA_USB2_PHY)        += phy-bcm-kona-usb2.o
>>>>>   obj-$(CONFIG_PHY_EXYNOS_DP_VIDEO)    += phy-exynos-dp-video.o
>>>>>   obj-$(CONFIG_PHY_EXYNOS_MIPI_VIDEO)    += phy-exynos-mipi-video.o
>>>>> +obj-$(CONFIG_PHY_EXYNOS_UFS)    += phy-exynos-ufs.o
>>>>>   obj-$(CONFIG_PHY_LPC18XX_USB_OTG)    += phy-lpc18xx-usb-otg.o
>>>>>   obj-$(CONFIG_PHY_PXA_28NM_USB2)        += phy-pxa-28nm-usb2.o
>>>>>   obj-$(CONFIG_PHY_PXA_28NM_HSIC)        += phy-pxa-28nm-hsic.o
>>>>> diff --git a/drivers/phy/phy-exynos-ufs.c
>>>>> b/drivers/phy/phy-exynos-ufs.c
>>>>> new file mode 100644
>>>>> index 000000000000..cb1aeaa3d4eb
>>>>> --- /dev/null
>>>>> +++ b/drivers/phy/phy-exynos-ufs.c
>>>>> @@ -0,0 +1,241 @@
>>>>> +/*
>>>>> + * UFS PHY driver for Samsung EXYNOS SoC
>>>>> + *
>>>>> + * Copyright (C) 2015 Samsung Electronics Co., Ltd.
>>>>> + * Author: Seungwon Jeon <essuuj@gmail.com>
>>>>> + *
>>>>> + * 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/clk.h>
>>>>> +#include <linux/delay.h>
>>>>> +#include <linux/err.h>
>>>>> +#include <linux/io.h>
>>>>> +#include <linux/iopoll.h>
>>>>> +#include <linux/mfd/syscon.h>
>>>>> +#include <linux/module.h>
>>>>> +#include <linux/of.h>
>>>>> +#include <linux/phy/phy.h>
>>>>> +#include <linux/phy/phy-exynos-ufs.h>
>>>>> +#include <linux/platform_device.h>
>>>>> +#include <linux/regmap.h>
>>>>> +
>>>>> +#include "phy-exynos-ufs.h"
>>>>> +
>>>>> +#define for_each_phy_lane(phy, i) \
>>>>> +    for (i = 0; i < (phy)->lane_cnt; i++)
>>>>> +#define for_each_phy_cfg(cfg) \
>>>>> +    for (; (cfg)->id; (cfg)++)
>>>>> +
>>>>> +#define PHY_DEF_LANE_CNT    1
>>>>> +
>>>>> +static void exynos_ufs_phy_config(struct exynos_ufs_phy *phy,
>>>>> +            const struct exynos_ufs_phy_cfg *cfg, u8 lane)
>>>>> +{
>>>>> +    enum {LANE_0, LANE_1}; /* lane index */
>>>>> +
>>>>> +    switch (lane) {
>>>>> +    case LANE_0:
>>>>> +        writel(cfg->val, (phy)->reg_pma + cfg->off_0);
>>>>> +        break;
>>>>> +    case LANE_1:
>>>>> +        if (cfg->id == PHY_TRSV_BLK)
>>>>> +            writel(cfg->val, (phy)->reg_pma + cfg->off_1);
>>>>> +        break;
>>>>> +    }
>>>>> +}
>>>>> +
>>>>> +static bool match_cfg_to_pwr_mode(u8 desc, u8 required_pwr)
>>>>> +{
>>>>> +    if (IS_PWR_MODE_ANY(desc))
>>>>> +        return true;
>>>>> +
>>>>> +    if (IS_PWR_MODE_HS(required_pwr) && IS_PWR_MODE_HS_ANY(desc))
>>>>> +        return true;
>>>>> +
>>>>> +    if (COMP_PWR_MODE(required_pwr, desc))
>>>>> +        return true;
>>>>> +
>>>>> +    if (COMP_PWR_MODE_MD(required_pwr, desc) &&
>>>>> +        COMP_PWR_MODE_GEAR(required_pwr, desc) &&
>>>>> +        COMP_PWR_MODE_SER(required_pwr, desc))
>>>>> +        return true;
>>>>> +
>>>>> +    return false;
>>>>> +}
>>>>> +
>>>>> +int exynos_ufs_phy_calibrate(struct phy *phy,
>>>>> +                    enum phy_cfg_tag tag, u8 pwr)
>>>>
>>>>
>>>> This is similar to the first version of your patch without
>>>> EXPORT_SYMBOL.
>>>>
>>>> I think you have to create a new generic PHY_OPS for calibrate PHY while
>>>> making
>>>> sure that it is as generic as possible (which means calibrate_phy
>>>> shouldn't
>>>> have tag and pwr arguments or a strong justification as to why those
>>>> arguments
>>>> are required in a generic API).
>>>
>>> I don't see the advantage to making this a generic phy_ops, this is
>>> exynos
>>> specific ufs-phy, please have a look at other implementations
>>
>>
>> only the implementation is specific to exynos. I've seen lot of other
>> vendors
>> want to do something like calibrate phy.
>>
>> So if we add something like (*calibrate)(struct phy *phy), then it can be
>> used
>> by others as well. Russell King also want to minimize the code to program
>> calibration settings. So it would be good to come up with a set of
>> standard
>> bindings like 'phy,tx-swing', 'phy,emphasis', 'phy,amplitude' etc.. to
>> program
>> these settings.
>>>
>>> drivers/phy/phy-qcom-ufs.c (which I belive mereged recently)
>>
>>
>> Thats why I hate when someone else merge PHY drivers :-( That driver can
>> as
>> well be in drivers/misc as it doesn't use PHY framework as it is supposed
>> to be
>> used. It just exports a dozen of API's to be used by controller drivers.
>> ick..
>>
>>> may be other vendors might come with there own implementation of phy.
>>
>>
>> right, it's all about providing the correct callback functions.
>>>
>>> I am using what is currently provided by the generic phy framework.
>>
>>
>> I think for your use case, what is currently provided in the PHY framework
>> is
>> not sufficient.
>>
> Its little over a year since last time we discuss about adding a generic
> calibration API. I can see in the past people tried adding *calibration* API
> [1] but not sure why [1] was not landed in mainline.
> Anyway now we have many users of phy_calibration API, like UFS, USB and may
> be PCIe, there is a real need to add this functionality. So, here is my
> approach:
>  * Along with [1], we can add a void *priv for handling device specific phy
> private data, and before calling phy_calibration() from phy consumer,
> phy->priv is populated with private data.
> This approach solves exynos-ufs-phy  calibration as well.
> please have a look on the snapshot below, if you are ok, will post a proper
> patch for this:
>
> [1]: https://patchwork.kernel.org/patch/4545941/
> ----

Ping!!!

> diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
> index a268f4d..78cec14 100644
> --- a/drivers/phy/phy-core.c
> +++ b/drivers/phy/phy-core.c
> @@ -357,6 +357,26 @@ int phy_set_mode(struct phy *phy, enum phy_mode mode)
>  }
>  EXPORT_SYMBOL_GPL(phy_set_mode);
>
> +int phy_calibrate(struct phy *phy)
> +{
> +       int ret = -ENOTSUPP;
> +
> +       if(!phy || !phy->ops->calibrate)
> +               return 0;
> +
> +       mutex_lock(&phy->mutex);
> +       ret = phy->ops->calibrate(phy);
> +       if (ret < 0) {
> +               dev_err(&phy->dev, "phy calibration failed %d\n", ret);
> +               goto out;
> +       }
> +
> +out:
> +       mutex_unlock(&phy->mutex);
> +
> +       return ret;
> +}
> +
>  int phy_reset(struct phy *phy)
>  {
>         int ret;
> diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
> index 78bb0d7..ca3a6d4 100644
> --- a/include/linux/phy/phy.h
> +++ b/include/linux/phy/phy.h
> @@ -45,6 +45,7 @@ struct phy_ops {
>         int     (*power_on)(struct phy *phy);
>         int     (*power_off)(struct phy *phy);
>         int     (*set_mode)(struct phy *phy, enum phy_mode mode);
> +       int     (*calibrate)(struct phy *phy);
>         int     (*reset)(struct phy *phy);
>         struct module *owner;
>  };
> @@ -67,6 +68,7 @@ struct phy_attrs {
>   * @init_count: used to protect when the PHY is used by multiple consumers
>   * @power_count: used to protect when the PHY is used by multiple consumers
>   * @phy_attrs: used to specify PHY specific attributes
> + * @priv: used to specify PHY specific private data
>   */
>  struct phy {
>         struct device           dev;
> @@ -77,6 +79,7 @@ struct phy {
>         int                     power_count;
>         struct phy_attrs        attrs;
>         struct regulator        *pwr;
> +       void                    *priv;
>  };
>
>  /**
> @@ -138,6 +141,7 @@ int phy_exit(struct phy *phy);
>  int phy_power_on(struct phy *phy);
>  int phy_power_off(struct phy *phy);
>  int phy_set_mode(struct phy *phy, enum phy_mode mode);
> +int phy_calibrate(struct phy *phy);
>  int phy_reset(struct phy *phy);
>  static inline int phy_get_bus_width(struct phy *phy)
>  {
> @@ -253,6 +257,13 @@ static inline int phy_set_mode(struct phy *phy, enum
> phy_mode mode)
>         return -ENOSYS;
>  }
>
> +static inline int phy_calibrate(struct phy *phy)
> +{
> +       if (!phy)
> +               return 0;
> +       return -ENOSYS;
> +}
> +
>  static inline int phy_reset(struct phy *phy)
>  {
>         if (!phy)
>
>> Thanks
>> Kishon
>>
>>
>



-- 
Regards,
Alim

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#1588510 — Re: [PATCH v5 02/11] phy: exynos-ufs: add UFS PHY driver for EXYNOS SoC

Hi,

On Thursday 23 February 2017 12:20 AM, Alim Akhtar wrote:
> On Fri, Feb 3, 2017 at 2:49 PM, Alim Akhtar <alim.akhtar@samsung.com> wrote:
>> Hi Kishon,
>>
>>
>> On 11/19/2015 07:09 PM, Kishon Vijay Abraham I wrote:
>>>
>>> Hi,
>>>
>>> On Tuesday 17 November 2015 01:41 PM, Alim Akhtar wrote:
>>>>
>>>> Hi
>>>> Thanks again for looking into this.
>>>>
>>>> On 11/17/2015 11:46 AM, Kishon Vijay Abraham I wrote:
>>>>>
>>>>> Hi,
>>>>>
>>>>> On Monday 09 November 2015 10:56 AM, Alim Akhtar wrote:
>>>>>>
>>>>>> From: Seungwon Jeon <essuuj@gmail.com>
>>>>>>
>>>>>> This patch introduces Exynos UFS PHY driver. This driver
>>>>>> supports to deal with phy calibration and power control
>>>>>> according to UFS host driver's behavior.
>>>>>>
>>>>>> Signed-off-by: Seungwon Jeon <essuuj@gmail.com>
>>>>>> Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
>>>>>> Cc: Kishon Vijay Abraham I <kishon@ti.com>
>>>>>> ---
>>>>>>   drivers/phy/Kconfig                |    7 ++
>>>>>>   drivers/phy/Makefile               |    1 +
>>>>>>   drivers/phy/phy-exynos-ufs.c       |  241
>>>>>> ++++++++++++++++++++++++++++++++++++
>>>>>>   drivers/phy/phy-exynos-ufs.h       |   85 +++++++++++++
>>>>>>   drivers/phy/phy-exynos7-ufs.h      |   89 +++++++++++++
>>>>>>   include/linux/phy/phy-exynos-ufs.h |   85 +++++++++++++
>>>>>>   6 files changed, 508 insertions(+)
>>>>>>   create mode 100644 drivers/phy/phy-exynos-ufs.c
>>>>>>   create mode 100644 drivers/phy/phy-exynos-ufs.h
>>>>>>   create mode 100644 drivers/phy/phy-exynos7-ufs.h
>>>>>>   create mode 100644 include/linux/phy/phy-exynos-ufs.h
>>>>>>
>>>>>> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
>>>>>> index 7eb5859dd035..7d38a92e0297 100644
>>>>>> --- a/drivers/phy/Kconfig
>>>>>> +++ b/drivers/phy/Kconfig
>>>>>> @@ -389,4 +389,11 @@ config PHY_CYGNUS_PCIE
>>>>>>         Enable this to support the Broadcom Cygnus PCIe PHY.
>>>>>>         If unsure, say N.
>>>>>>
>>>>>> +config PHY_EXYNOS_UFS
>>>>>> +    tristate "EXYNOS SoC series UFS PHY driver"
>>>>>> +    depends on OF && ARCH_EXYNOS || COMPILE_TEST
>>>>>> +    select GENERIC_PHY
>>>>>> +    help
>>>>>> +      Support for UFS PHY on Samsung EXYNOS chipsets.
>>>>>> +
>>>>>>   endmenu
>>>>>> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
>>>>>> index 075db1a81aa5..9bec4d1a89e1 100644
>>>>>> --- a/drivers/phy/Makefile
>>>>>> +++ b/drivers/phy/Makefile
>>>>>> @@ -10,6 +10,7 @@ obj-$(CONFIG_ARMADA375_USBCLUSTER_PHY)    +=
>>>>>> phy-armada375-usb2.o
>>>>>>   obj-$(CONFIG_BCM_KONA_USB2_PHY)        += phy-bcm-kona-usb2.o
>>>>>>   obj-$(CONFIG_PHY_EXYNOS_DP_VIDEO)    += phy-exynos-dp-video.o
>>>>>>   obj-$(CONFIG_PHY_EXYNOS_MIPI_VIDEO)    += phy-exynos-mipi-video.o
>>>>>> +obj-$(CONFIG_PHY_EXYNOS_UFS)    += phy-exynos-ufs.o
>>>>>>   obj-$(CONFIG_PHY_LPC18XX_USB_OTG)    += phy-lpc18xx-usb-otg.o
>>>>>>   obj-$(CONFIG_PHY_PXA_28NM_USB2)        += phy-pxa-28nm-usb2.o
>>>>>>   obj-$(CONFIG_PHY_PXA_28NM_HSIC)        += phy-pxa-28nm-hsic.o
>>>>>> diff --git a/drivers/phy/phy-exynos-ufs.c
>>>>>> b/drivers/phy/phy-exynos-ufs.c
>>>>>> new file mode 100644
>>>>>> index 000000000000..cb1aeaa3d4eb
>>>>>> --- /dev/null
>>>>>> +++ b/drivers/phy/phy-exynos-ufs.c
>>>>>> @@ -0,0 +1,241 @@
>>>>>> +/*
>>>>>> + * UFS PHY driver for Samsung EXYNOS SoC
>>>>>> + *
>>>>>> + * Copyright (C) 2015 Samsung Electronics Co., Ltd.
>>>>>> + * Author: Seungwon Jeon <essuuj@gmail.com>
>>>>>> + *
>>>>>> + * 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/clk.h>
>>>>>> +#include <linux/delay.h>
>>>>>> +#include <linux/err.h>
>>>>>> +#include <linux/io.h>
>>>>>> +#include <linux/iopoll.h>
>>>>>> +#include <linux/mfd/syscon.h>
>>>>>> +#include <linux/module.h>
>>>>>> +#include <linux/of.h>
>>>>>> +#include <linux/phy/phy.h>
>>>>>> +#include <linux/phy/phy-exynos-ufs.h>
>>>>>> +#include <linux/platform_device.h>
>>>>>> +#include <linux/regmap.h>
>>>>>> +
>>>>>> +#include "phy-exynos-ufs.h"
>>>>>> +
>>>>>> +#define for_each_phy_lane(phy, i) \
>>>>>> +    for (i = 0; i < (phy)->lane_cnt; i++)
>>>>>> +#define for_each_phy_cfg(cfg) \
>>>>>> +    for (; (cfg)->id; (cfg)++)
>>>>>> +
>>>>>> +#define PHY_DEF_LANE_CNT    1
>>>>>> +
>>>>>> +static void exynos_ufs_phy_config(struct exynos_ufs_phy *phy,
>>>>>> +            const struct exynos_ufs_phy_cfg *cfg, u8 lane)
>>>>>> +{
>>>>>> +    enum {LANE_0, LANE_1}; /* lane index */
>>>>>> +
>>>>>> +    switch (lane) {
>>>>>> +    case LANE_0:
>>>>>> +        writel(cfg->val, (phy)->reg_pma + cfg->off_0);
>>>>>> +        break;
>>>>>> +    case LANE_1:
>>>>>> +        if (cfg->id == PHY_TRSV_BLK)
>>>>>> +            writel(cfg->val, (phy)->reg_pma + cfg->off_1);
>>>>>> +        break;
>>>>>> +    }
>>>>>> +}
>>>>>> +
>>>>>> +static bool match_cfg_to_pwr_mode(u8 desc, u8 required_pwr)
>>>>>> +{
>>>>>> +    if (IS_PWR_MODE_ANY(desc))
>>>>>> +        return true;
>>>>>> +
>>>>>> +    if (IS_PWR_MODE_HS(required_pwr) && IS_PWR_MODE_HS_ANY(desc))
>>>>>> +        return true;
>>>>>> +
>>>>>> +    if (COMP_PWR_MODE(required_pwr, desc))
>>>>>> +        return true;
>>>>>> +
>>>>>> +    if (COMP_PWR_MODE_MD(required_pwr, desc) &&
>>>>>> +        COMP_PWR_MODE_GEAR(required_pwr, desc) &&
>>>>>> +        COMP_PWR_MODE_SER(required_pwr, desc))
>>>>>> +        return true;
>>>>>> +
>>>>>> +    return false;
>>>>>> +}
>>>>>> +
>>>>>> +int exynos_ufs_phy_calibrate(struct phy *phy,
>>>>>> +                    enum phy_cfg_tag tag, u8 pwr)
>>>>>
>>>>>
>>>>> This is similar to the first version of your patch without
>>>>> EXPORT_SYMBOL.
>>>>>
>>>>> I think you have to create a new generic PHY_OPS for calibrate PHY while
>>>>> making
>>>>> sure that it is as generic as possible (which means calibrate_phy
>>>>> shouldn't
>>>>> have tag and pwr arguments or a strong justification as to why those
>>>>> arguments
>>>>> are required in a generic API).
>>>>
>>>> I don't see the advantage to making this a generic phy_ops, this is
>>>> exynos
>>>> specific ufs-phy, please have a look at other implementations
>>>
>>>
>>> only the implementation is specific to exynos. I've seen lot of other
>>> vendors
>>> want to do something like calibrate phy.
>>>
>>> So if we add something like (*calibrate)(struct phy *phy), then it can be
>>> used
>>> by others as well. Russell King also want to minimize the code to program
>>> calibration settings. So it would be good to come up with a set of
>>> standard
>>> bindings like 'phy,tx-swing', 'phy,emphasis', 'phy,amplitude' etc.. to
>>> program
>>> these settings.
>>>>
>>>> drivers/phy/phy-qcom-ufs.c (which I belive mereged recently)
>>>
>>>
>>> Thats why I hate when someone else merge PHY drivers :-( That driver can
>>> as
>>> well be in drivers/misc as it doesn't use PHY framework as it is supposed
>>> to be
>>> used. It just exports a dozen of API's to be used by controller drivers.
>>> ick..
>>>
>>>> may be other vendors might come with there own implementation of phy.
>>>
>>>
>>> right, it's all about providing the correct callback functions.
>>>>
>>>> I am using what is currently provided by the generic phy framework.
>>>
>>>
>>> I think for your use case, what is currently provided in the PHY framework
>>> is
>>> not sufficient.
>>>
>> Its little over a year since last time we discuss about adding a generic
>> calibration API. I can see in the past people tried adding *calibration* API
>> [1] but not sure why [1] was not landed in mainline.
>> Anyway now we have many users of phy_calibration API, like UFS, USB and may
>> be PCIe, there is a real need to add this functionality. So, here is my
>> approach:

Agree, there are quite a few users that require calibration of phy parameters.
I think previously it was accommodated in phy_init, hence it was not merged.
>>  * Along with [1], we can add a void *priv for handling device specific phy
>> private data, and before calling phy_calibration() from phy consumer,
>> phy->priv is populated with private data.

Not sure how you plan to use priv here?

Thanks
Kishon

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#1588674

Hi Kishon,

On 02/27/2017 10:56 AM, Kishon Vijay Abraham I wrote:
> Hi,
>
> On Thursday 23 February 2017 12:20 AM, Alim Akhtar wrote:
>> On Fri, Feb 3, 2017 at 2:49 PM, Alim Akhtar <alim.akhtar@samsung.com> wrote:
>>> Hi Kishon,
>>>
>>>
>>> On 11/19/2015 07:09 PM, Kishon Vijay Abraham I wrote:
>>>>
>>>> Hi,
>>>>
>>>> On Tuesday 17 November 2015 01:41 PM, Alim Akhtar wrote:
>>>>>
>>>>> Hi
>>>>> Thanks again for looking into this.
>>>>>
>>>>> On 11/17/2015 11:46 AM, Kishon Vijay Abraham I wrote:
>>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> On Monday 09 November 2015 10:56 AM, Alim Akhtar wrote:
>>>>>>>
>>>>>>> From: Seungwon Jeon <essuuj@gmail.com>
>>>>>>>
>>>>>>> This patch introduces Exynos UFS PHY driver. This driver
>>>>>>> supports to deal with phy calibration and power control
>>>>>>> according to UFS host driver's behavior.
>>>>>>>
>>>>>>> Signed-off-by: Seungwon Jeon <essuuj@gmail.com>
>>>>>>> Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
>>>>>>> Cc: Kishon Vijay Abraham I <kishon@ti.com>
>>>>>>> ---
>>>>>>>   drivers/phy/Kconfig                |    7 ++
>>>>>>>   drivers/phy/Makefile               |    1 +
>>>>>>>   drivers/phy/phy-exynos-ufs.c       |  241
>>>>>>> ++++++++++++++++++++++++++++++++++++
>>>>>>>   drivers/phy/phy-exynos-ufs.h       |   85 +++++++++++++
>>>>>>>   drivers/phy/phy-exynos7-ufs.h      |   89 +++++++++++++
>>>>>>>   include/linux/phy/phy-exynos-ufs.h |   85 +++++++++++++
>>>>>>>   6 files changed, 508 insertions(+)
>>>>>>>   create mode 100644 drivers/phy/phy-exynos-ufs.c
>>>>>>>   create mode 100644 drivers/phy/phy-exynos-ufs.h
>>>>>>>   create mode 100644 drivers/phy/phy-exynos7-ufs.h
>>>>>>>   create mode 100644 include/linux/phy/phy-exynos-ufs.h
>>>>>>>
>>>>>>> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
>>>>>>> index 7eb5859dd035..7d38a92e0297 100644
>>>>>>> --- a/drivers/phy/Kconfig
>>>>>>> +++ b/drivers/phy/Kconfig
>>>>>>> @@ -389,4 +389,11 @@ config PHY_CYGNUS_PCIE
>>>>>>>         Enable this to support the Broadcom Cygnus PCIe PHY.
>>>>>>>         If unsure, say N.
>>>>>>>
>>>>>>> +config PHY_EXYNOS_UFS
>>>>>>> +    tristate "EXYNOS SoC series UFS PHY driver"
>>>>>>> +    depends on OF && ARCH_EXYNOS || COMPILE_TEST
>>>>>>> +    select GENERIC_PHY
>>>>>>> +    help
>>>>>>> +      Support for UFS PHY on Samsung EXYNOS chipsets.
>>>>>>> +
>>>>>>>   endmenu
>>>>>>> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
>>>>>>> index 075db1a81aa5..9bec4d1a89e1 100644
>>>>>>> --- a/drivers/phy/Makefile
>>>>>>> +++ b/drivers/phy/Makefile
>>>>>>> @@ -10,6 +10,7 @@ obj-$(CONFIG_ARMADA375_USBCLUSTER_PHY)    +=
>>>>>>> phy-armada375-usb2.o
>>>>>>>   obj-$(CONFIG_BCM_KONA_USB2_PHY)        += phy-bcm-kona-usb2.o
>>>>>>>   obj-$(CONFIG_PHY_EXYNOS_DP_VIDEO)    += phy-exynos-dp-video.o
>>>>>>>   obj-$(CONFIG_PHY_EXYNOS_MIPI_VIDEO)    += phy-exynos-mipi-video.o
>>>>>>> +obj-$(CONFIG_PHY_EXYNOS_UFS)    += phy-exynos-ufs.o
>>>>>>>   obj-$(CONFIG_PHY_LPC18XX_USB_OTG)    += phy-lpc18xx-usb-otg.o
>>>>>>>   obj-$(CONFIG_PHY_PXA_28NM_USB2)        += phy-pxa-28nm-usb2.o
>>>>>>>   obj-$(CONFIG_PHY_PXA_28NM_HSIC)        += phy-pxa-28nm-hsic.o
>>>>>>> diff --git a/drivers/phy/phy-exynos-ufs.c
>>>>>>> b/drivers/phy/phy-exynos-ufs.c
>>>>>>> new file mode 100644
>>>>>>> index 000000000000..cb1aeaa3d4eb
>>>>>>> --- /dev/null
>>>>>>> +++ b/drivers/phy/phy-exynos-ufs.c
>>>>>>> @@ -0,0 +1,241 @@
>>>>>>> +/*
>>>>>>> + * UFS PHY driver for Samsung EXYNOS SoC
>>>>>>> + *
>>>>>>> + * Copyright (C) 2015 Samsung Electronics Co., Ltd.
>>>>>>> + * Author: Seungwon Jeon <essuuj@gmail.com>
>>>>>>> + *
>>>>>>> + * 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/clk.h>
>>>>>>> +#include <linux/delay.h>
>>>>>>> +#include <linux/err.h>
>>>>>>> +#include <linux/io.h>
>>>>>>> +#include <linux/iopoll.h>
>>>>>>> +#include <linux/mfd/syscon.h>
>>>>>>> +#include <linux/module.h>
>>>>>>> +#include <linux/of.h>
>>>>>>> +#include <linux/phy/phy.h>
>>>>>>> +#include <linux/phy/phy-exynos-ufs.h>
>>>>>>> +#include <linux/platform_device.h>
>>>>>>> +#include <linux/regmap.h>
>>>>>>> +
>>>>>>> +#include "phy-exynos-ufs.h"
>>>>>>> +
>>>>>>> +#define for_each_phy_lane(phy, i) \
>>>>>>> +    for (i = 0; i < (phy)->lane_cnt; i++)
>>>>>>> +#define for_each_phy_cfg(cfg) \
>>>>>>> +    for (; (cfg)->id; (cfg)++)
>>>>>>> +
>>>>>>> +#define PHY_DEF_LANE_CNT    1
>>>>>>> +
>>>>>>> +static void exynos_ufs_phy_config(struct exynos_ufs_phy *phy,
>>>>>>> +            const struct exynos_ufs_phy_cfg *cfg, u8 lane)
>>>>>>> +{
>>>>>>> +    enum {LANE_0, LANE_1}; /* lane index */
>>>>>>> +
>>>>>>> +    switch (lane) {
>>>>>>> +    case LANE_0:
>>>>>>> +        writel(cfg->val, (phy)->reg_pma + cfg->off_0);
>>>>>>> +        break;
>>>>>>> +    case LANE_1:
>>>>>>> +        if (cfg->id == PHY_TRSV_BLK)
>>>>>>> +            writel(cfg->val, (phy)->reg_pma + cfg->off_1);
>>>>>>> +        break;
>>>>>>> +    }
>>>>>>> +}
>>>>>>> +
>>>>>>> +static bool match_cfg_to_pwr_mode(u8 desc, u8 required_pwr)
>>>>>>> +{
>>>>>>> +    if (IS_PWR_MODE_ANY(desc))
>>>>>>> +        return true;
>>>>>>> +
>>>>>>> +    if (IS_PWR_MODE_HS(required_pwr) && IS_PWR_MODE_HS_ANY(desc))
>>>>>>> +        return true;
>>>>>>> +
>>>>>>> +    if (COMP_PWR_MODE(required_pwr, desc))
>>>>>>> +        return true;
>>>>>>> +
>>>>>>> +    if (COMP_PWR_MODE_MD(required_pwr, desc) &&
>>>>>>> +        COMP_PWR_MODE_GEAR(required_pwr, desc) &&
>>>>>>> +        COMP_PWR_MODE_SER(required_pwr, desc))
>>>>>>> +        return true;
>>>>>>> +
>>>>>>> +    return false;
>>>>>>> +}
>>>>>>> +
>>>>>>> +int exynos_ufs_phy_calibrate(struct phy *phy,
>>>>>>> +                    enum phy_cfg_tag tag, u8 pwr)
>>>>>>
>>>>>>
>>>>>> This is similar to the first version of your patch without
>>>>>> EXPORT_SYMBOL.
>>>>>>
>>>>>> I think you have to create a new generic PHY_OPS for calibrate PHY while
>>>>>> making
>>>>>> sure that it is as generic as possible (which means calibrate_phy
>>>>>> shouldn't
>>>>>> have tag and pwr arguments or a strong justification as to why those
>>>>>> arguments
>>>>>> are required in a generic API).
>>>>>
>>>>> I don't see the advantage to making this a generic phy_ops, this is
>>>>> exynos
>>>>> specific ufs-phy, please have a look at other implementations
>>>>
>>>>
>>>> only the implementation is specific to exynos. I've seen lot of other
>>>> vendors
>>>> want to do something like calibrate phy.
>>>>
>>>> So if we add something like (*calibrate)(struct phy *phy), then it can be
>>>> used
>>>> by others as well. Russell King also want to minimize the code to program
>>>> calibration settings. So it would be good to come up with a set of
>>>> standard
>>>> bindings like 'phy,tx-swing', 'phy,emphasis', 'phy,amplitude' etc.. to
>>>> program
>>>> these settings.
>>>>>
>>>>> drivers/phy/phy-qcom-ufs.c (which I belive mereged recently)
>>>>
>>>>
>>>> Thats why I hate when someone else merge PHY drivers :-( That driver can
>>>> as
>>>> well be in drivers/misc as it doesn't use PHY framework as it is supposed
>>>> to be
>>>> used. It just exports a dozen of API's to be used by controller drivers.
>>>> ick..
>>>>
>>>>> may be other vendors might come with there own implementation of phy.
>>>>
>>>>
>>>> right, it's all about providing the correct callback functions.
>>>>>
>>>>> I am using what is currently provided by the generic phy framework.
>>>>
>>>>
>>>> I think for your use case, what is currently provided in the PHY framework
>>>> is
>>>> not sufficient.
>>>>
>>> Its little over a year since last time we discuss about adding a generic
>>> calibration API. I can see in the past people tried adding *calibration* API
>>> [1] but not sure why [1] was not landed in mainline.
>>> Anyway now we have many users of phy_calibration API, like UFS, USB and may
>>> be PCIe, there is a real need to add this functionality. So, here is my
>>> approach:
>
> Agree, there are quite a few users that require calibration of phy parameters.
> I think previously it was accommodated in phy_init, hence it was not merged.
Ok, thanks for this information.

>>>  * Along with [1], we can add a void *priv for handling device specific phy
>>> private data, and before calling phy_calibration() from phy consumer,
>>> phy->priv is populated with private data.
>
> Not sure how you plan to use priv here?
>
 From ufs driver I am populating PHY _priv_ data and calling phy_calibrate()

e.g
----------------------- from ufs-exynos.c
Instead of using below code earlier
- exynos_ufs_phy_calibrate(generic_phy,CFG_PRE_INIT,PWR_MODE_ANY);

Now I am using below from ufs-exynos driver

+ generic_phy->priv =(void*)CFG_PRE_INIT;
+ phy_calibrate(generic_phy);

and in drivers/phy/phy-exynos-ufs.c
using phy->priv in calibration function.

Let me know if you need more details here.

I think this will work well for other drivers like PCIe or USB etc.

> Thanks
> Kishon
>
>
>

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#1589274

Hi Kishon,

On 02/28/2017 09:04 AM, Kishon Vijay Abraham I wrote:
> Hi,
>
> On Monday 27 February 2017 07:40 PM, Alim Akhtar wrote:
>> Hi Kishon,
>>
>> On 02/27/2017 10:56 AM, Kishon Vijay Abraham I wrote:
>>> Hi,
>>>
>>> On Thursday 23 February 2017 12:20 AM, Alim Akhtar wrote:
>>>> On Fri, Feb 3, 2017 at 2:49 PM, Alim Akhtar <alim.akhtar@samsung.com> wrote:
>>>>> Hi Kishon,
>>>>>
>>>>>
>>>>> On 11/19/2015 07:09 PM, Kishon Vijay Abraham I wrote:
>>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> On Tuesday 17 November 2015 01:41 PM, Alim Akhtar wrote:
>>>>>>>
>>>>>>> Hi
>>>>>>> Thanks again for looking into this.
>>>>>>>
>>>>>>> On 11/17/2015 11:46 AM, Kishon Vijay Abraham I wrote:
>>>>>>>>
>>>>>>>> Hi,
>>>>>>>>
>>>>>>>> On Monday 09 November 2015 10:56 AM, Alim Akhtar wrote:
>>>>>>>>>
>>>>>>>>> From: Seungwon Jeon <essuuj@gmail.com>
>>>>>>>>>
>>>>>>>>> This patch introduces Exynos UFS PHY driver. This driver
>>>>>>>>> supports to deal with phy calibration and power control
>>>>>>>>> according to UFS host driver's behavior.
>>>>>>>>>
>>>>>>>>> Signed-off-by: Seungwon Jeon <essuuj@gmail.com>
>>>>>>>>> Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
>>>>>>>>> Cc: Kishon Vijay Abraham I <kishon@ti.com>
>>>>>>>>> ---
>>>>>>>>>   drivers/phy/Kconfig                |    7 ++
>>>>>>>>>   drivers/phy/Makefile               |    1 +
>>>>>>>>>   drivers/phy/phy-exynos-ufs.c       |  241
>>>>>>>>> ++++++++++++++++++++++++++++++++++++
>>>>>>>>>   drivers/phy/phy-exynos-ufs.h       |   85 +++++++++++++
>>>>>>>>>   drivers/phy/phy-exynos7-ufs.h      |   89 +++++++++++++
>>>>>>>>>   include/linux/phy/phy-exynos-ufs.h |   85 +++++++++++++
>>>>>>>>>   6 files changed, 508 insertions(+)
>>>>>>>>>   create mode 100644 drivers/phy/phy-exynos-ufs.c
>>>>>>>>>   create mode 100644 drivers/phy/phy-exynos-ufs.h
>>>>>>>>>   create mode 100644 drivers/phy/phy-exynos7-ufs.h
>>>>>>>>>   create mode 100644 include/linux/phy/phy-exynos-ufs.h
>>>>>>>>>
>>>>>>>>> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
>>>>>>>>> index 7eb5859dd035..7d38a92e0297 100644
>>>>>>>>> --- a/drivers/phy/Kconfig
>>>>>>>>> +++ b/drivers/phy/Kconfig
>>>>>>>>> @@ -389,4 +389,11 @@ config PHY_CYGNUS_PCIE
>>>>>>>>>         Enable this to support the Broadcom Cygnus PCIe PHY.
>>>>>>>>>         If unsure, say N.
>>>>>>>>>
>>>>>>>>> +config PHY_EXYNOS_UFS
>>>>>>>>> +    tristate "EXYNOS SoC series UFS PHY driver"
>>>>>>>>> +    depends on OF && ARCH_EXYNOS || COMPILE_TEST
>>>>>>>>> +    select GENERIC_PHY
>>>>>>>>> +    help
>>>>>>>>> +      Support for UFS PHY on Samsung EXYNOS chipsets.
>>>>>>>>> +
>>>>>>>>>   endmenu
>>>>>>>>> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
>>>>>>>>> index 075db1a81aa5..9bec4d1a89e1 100644
>>>>>>>>> --- a/drivers/phy/Makefile
>>>>>>>>> +++ b/drivers/phy/Makefile
>>>>>>>>> @@ -10,6 +10,7 @@ obj-$(CONFIG_ARMADA375_USBCLUSTER_PHY)    +=
>>>>>>>>> phy-armada375-usb2.o
>>>>>>>>>   obj-$(CONFIG_BCM_KONA_USB2_PHY)        += phy-bcm-kona-usb2.o
>>>>>>>>>   obj-$(CONFIG_PHY_EXYNOS_DP_VIDEO)    += phy-exynos-dp-video.o
>>>>>>>>>   obj-$(CONFIG_PHY_EXYNOS_MIPI_VIDEO)    += phy-exynos-mipi-video.o
>>>>>>>>> +obj-$(CONFIG_PHY_EXYNOS_UFS)    += phy-exynos-ufs.o
>>>>>>>>>   obj-$(CONFIG_PHY_LPC18XX_USB_OTG)    += phy-lpc18xx-usb-otg.o
>>>>>>>>>   obj-$(CONFIG_PHY_PXA_28NM_USB2)        += phy-pxa-28nm-usb2.o
>>>>>>>>>   obj-$(CONFIG_PHY_PXA_28NM_HSIC)        += phy-pxa-28nm-hsic.o
>>>>>>>>> diff --git a/drivers/phy/phy-exynos-ufs.c
>>>>>>>>> b/drivers/phy/phy-exynos-ufs.c
>>>>>>>>> new file mode 100644
>>>>>>>>> index 000000000000..cb1aeaa3d4eb
>>>>>>>>> --- /dev/null
>>>>>>>>> +++ b/drivers/phy/phy-exynos-ufs.c
>>>>>>>>> @@ -0,0 +1,241 @@
>>>>>>>>> +/*
>>>>>>>>> + * UFS PHY driver for Samsung EXYNOS SoC
>>>>>>>>> + *
>>>>>>>>> + * Copyright (C) 2015 Samsung Electronics Co., Ltd.
>>>>>>>>> + * Author: Seungwon Jeon <essuuj@gmail.com>
>>>>>>>>> + *
>>>>>>>>> + * 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/clk.h>
>>>>>>>>> +#include <linux/delay.h>
>>>>>>>>> +#include <linux/err.h>
>>>>>>>>> +#include <linux/io.h>
>>>>>>>>> +#include <linux/iopoll.h>
>>>>>>>>> +#include <linux/mfd/syscon.h>
>>>>>>>>> +#include <linux/module.h>
>>>>>>>>> +#include <linux/of.h>
>>>>>>>>> +#include <linux/phy/phy.h>
>>>>>>>>> +#include <linux/phy/phy-exynos-ufs.h>
>>>>>>>>> +#include <linux/platform_device.h>
>>>>>>>>> +#include <linux/regmap.h>
>>>>>>>>> +
>>>>>>>>> +#include "phy-exynos-ufs.h"
>>>>>>>>> +
>>>>>>>>> +#define for_each_phy_lane(phy, i) \
>>>>>>>>> +    for (i = 0; i < (phy)->lane_cnt; i++)
>>>>>>>>> +#define for_each_phy_cfg(cfg) \
>>>>>>>>> +    for (; (cfg)->id; (cfg)++)
>>>>>>>>> +
>>>>>>>>> +#define PHY_DEF_LANE_CNT    1
>>>>>>>>> +
>>>>>>>>> +static void exynos_ufs_phy_config(struct exynos_ufs_phy *phy,
>>>>>>>>> +            const struct exynos_ufs_phy_cfg *cfg, u8 lane)
>>>>>>>>> +{
>>>>>>>>> +    enum {LANE_0, LANE_1}; /* lane index */
>>>>>>>>> +
>>>>>>>>> +    switch (lane) {
>>>>>>>>> +    case LANE_0:
>>>>>>>>> +        writel(cfg->val, (phy)->reg_pma + cfg->off_0);
>>>>>>>>> +        break;
>>>>>>>>> +    case LANE_1:
>>>>>>>>> +        if (cfg->id == PHY_TRSV_BLK)
>>>>>>>>> +            writel(cfg->val, (phy)->reg_pma + cfg->off_1);
>>>>>>>>> +        break;
>>>>>>>>> +    }
>>>>>>>>> +}
>>>>>>>>> +
>>>>>>>>> +static bool match_cfg_to_pwr_mode(u8 desc, u8 required_pwr)
>>>>>>>>> +{
>>>>>>>>> +    if (IS_PWR_MODE_ANY(desc))
>>>>>>>>> +        return true;
>>>>>>>>> +
>>>>>>>>> +    if (IS_PWR_MODE_HS(required_pwr) && IS_PWR_MODE_HS_ANY(desc))
>>>>>>>>> +        return true;
>>>>>>>>> +
>>>>>>>>> +    if (COMP_PWR_MODE(required_pwr, desc))
>>>>>>>>> +        return true;
>>>>>>>>> +
>>>>>>>>> +    if (COMP_PWR_MODE_MD(required_pwr, desc) &&
>>>>>>>>> +        COMP_PWR_MODE_GEAR(required_pwr, desc) &&
>>>>>>>>> +        COMP_PWR_MODE_SER(required_pwr, desc))
>>>>>>>>> +        return true;
>>>>>>>>> +
>>>>>>>>> +    return false;
>>>>>>>>> +}
>>>>>>>>> +
>>>>>>>>> +int exynos_ufs_phy_calibrate(struct phy *phy,
>>>>>>>>> +                    enum phy_cfg_tag tag, u8 pwr)
>>>>>>>>
>>>>>>>>
>>>>>>>> This is similar to the first version of your patch without
>>>>>>>> EXPORT_SYMBOL.
>>>>>>>>
>>>>>>>> I think you have to create a new generic PHY_OPS for calibrate PHY while
>>>>>>>> making
>>>>>>>> sure that it is as generic as possible (which means calibrate_phy
>>>>>>>> shouldn't
>>>>>>>> have tag and pwr arguments or a strong justification as to why those
>>>>>>>> arguments
>>>>>>>> are required in a generic API).
>>>>>>>
>>>>>>> I don't see the advantage to making this a generic phy_ops, this is
>>>>>>> exynos
>>>>>>> specific ufs-phy, please have a look at other implementations
>>>>>>
>>>>>>
>>>>>> only the implementation is specific to exynos. I've seen lot of other
>>>>>> vendors
>>>>>> want to do something like calibrate phy.
>>>>>>
>>>>>> So if we add something like (*calibrate)(struct phy *phy), then it can be
>>>>>> used
>>>>>> by others as well. Russell King also want to minimize the code to program
>>>>>> calibration settings. So it would be good to come up with a set of
>>>>>> standard
>>>>>> bindings like 'phy,tx-swing', 'phy,emphasis', 'phy,amplitude' etc.. to
>>>>>> program
>>>>>> these settings.
>>>>>>>
>>>>>>> drivers/phy/phy-qcom-ufs.c (which I belive mereged recently)
>>>>>>
>>>>>>
>>>>>> Thats why I hate when someone else merge PHY drivers :-( That driver can
>>>>>> as
>>>>>> well be in drivers/misc as it doesn't use PHY framework as it is supposed
>>>>>> to be
>>>>>> used. It just exports a dozen of API's to be used by controller drivers.
>>>>>> ick..
>>>>>>
>>>>>>> may be other vendors might come with there own implementation of phy.
>>>>>>
>>>>>>
>>>>>> right, it's all about providing the correct callback functions.
>>>>>>>
>>>>>>> I am using what is currently provided by the generic phy framework.
>>>>>>
>>>>>>
>>>>>> I think for your use case, what is currently provided in the PHY framework
>>>>>> is
>>>>>> not sufficient.
>>>>>>
>>>>> Its little over a year since last time we discuss about adding a generic
>>>>> calibration API. I can see in the past people tried adding *calibration* API
>>>>> [1] but not sure why [1] was not landed in mainline.
>>>>> Anyway now we have many users of phy_calibration API, like UFS, USB and may
>>>>> be PCIe, there is a real need to add this functionality. So, here is my
>>>>> approach:
>>>
>>> Agree, there are quite a few users that require calibration of phy parameters.
>>> I think previously it was accommodated in phy_init, hence it was not merged.
>> Ok, thanks for this information.
>>
>>>>>  * Along with [1], we can add a void *priv for handling device specific phy
>>>>> private data, and before calling phy_calibration() from phy consumer,
>>>>> phy->priv is populated with private data.
>>>
>>> Not sure how you plan to use priv here?
>>>
>>  From ufs driver I am populating PHY _priv_ data and calling phy_calibrate()
>>
>> e.g
>> ----------------------- from ufs-exynos.c
>> Instead of using below code earlier
>> - exynos_ufs_phy_calibrate(generic_phy,CFG_PRE_INIT,PWR_MODE_ANY);
>>
>> Now I am using below from ufs-exynos driver
>>
>> + generic_phy->priv =(void*)CFG_PRE_INIT;
>> + phy_calibrate(generic_phy);
>>
>> and in drivers/phy/phy-exynos-ufs.c
>> using phy->priv in calibration function.
>
> Don't prefer passing of such private pointers between drivers. Why is this needed?
>
As already explained before, this is needed to pass the calibration 
point (when you want to do the calibration?, like before init, after 
init or before/after _mode_ change etc).

I Don't think we have much option here, if we want to make 
phy_calibration generic enough.

We have few options:
1> One way is to have phy_calibration takes some argument like 
calibration point (which was part of  my v3~v5), but looking at the 
current implementation of phy-qcom-ufs.c, this approach might not be 
generic enough.

2> And using EXPORT_SYMBOL way is not encourage (as in my V1, even 
though others in phy drivers uses it).

3> the current proposal of using _priv_ data.

Out of the above 3 option, I feel using _priv_ data is more generic way 
(and most of the major sub-system in Linux uses it).

lets see what other people think about __priv__ approach.

Please suggest your prefer way to handle this.

> Thanks
> Kishon
>
>
>

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