[PATCH V7 1/2] scsi: ufs: set the device reference clock setting

[PATCH V7 1/2] scsi: ufs: set the device reference clock setting

[Sayali Lokhande]

From: Subhash Jadavani <subhashj@codeaurora.org>

UFS host supplies the reference clock to UFS device and UFS device
specification allows host to provide one of the 4 frequencies (19.2 MHz,
26 MHz, 38.4 MHz, 52 MHz) for reference clock. Host should set the
device reference clock frequency setting in the device based on what
frequency it is supplying to UFS device.

Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Sayali Lokhande <sayalil@codeaurora.org>
---
 drivers/scsi/ufs/ufs.h           |  8 ++++
 drivers/scsi/ufs/ufshcd-pltfrm.c |  2 +
 drivers/scsi/ufs/ufshcd.c        | 84 ++++++++++++++++++++++++++++++++++++++++
 drivers/scsi/ufs/ufshcd.h        |  2 +
 4 files changed, 96 insertions(+)

diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index 14e5bf7..89e0a33 100644
--- a/drivers/scsi/ufs/ufs.h
+++ b/drivers/scsi/ufs/ufs.h
@@ -378,6 +378,14 @@ enum query_opcode {
 	UPIU_QUERY_OPCODE_TOGGLE_FLAG	= 0x8,
 };
 
+/* bRefClkFreq attribute values */
+enum ref_clk_freq {
+	REF_CLK_FREQ_19_2_MHZ	= 19200000,
+	REF_CLK_FREQ_26_MHZ	= 26000000,
+	REF_CLK_FREQ_38_4_MHZ	= 38400000,
+	REF_CLK_FREQ_52_MHZ	= 52000000,
+};
+
 /* Query response result code */
 enum {
 	QUERY_RESULT_SUCCESS                    = 0x00,
diff --git a/drivers/scsi/ufs/ufshcd-pltfrm.c b/drivers/scsi/ufs/ufshcd-pltfrm.c
index e82bde0..0953563 100644
--- a/drivers/scsi/ufs/ufshcd-pltfrm.c
+++ b/drivers/scsi/ufs/ufshcd-pltfrm.c
@@ -343,6 +343,8 @@ int ufshcd_pltfrm_init(struct platform_device *pdev,
 	pm_runtime_set_active(&pdev->dev);
 	pm_runtime_enable(&pdev->dev);
 
+	ufshcd_parse_dev_ref_clk_freq(hba);
+
 	ufshcd_init_lanes_per_dir(hba);
 
 	err = ufshcd_init(hba, mmio_base, irq);
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index c5b1bf1..619313b 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -6296,6 +6296,84 @@ static void ufshcd_def_desc_sizes(struct ufs_hba *hba)
 	hba->desc_size.hlth_desc = QUERY_DESC_HEALTH_DEF_SIZE;
 }
 
+void ufshcd_parse_dev_ref_clk_freq(struct ufs_hba *hba)
+{
+	struct device *dev = hba->dev;
+	struct device_node *np = dev->of_node;
+	struct clk *refclk = NULL;
+
+	if (!np)
+		return;
+
+	refclk = of_clk_get_by_name(np, "ref_clk");
+	if (refclk)
+		hba->dev_ref_clk_freq  = clk_get_rate(refclk);
+	else if (!refclk ||
+		(hba->dev_ref_clk_freq > REF_CLK_FREQ_52_MHZ)) {
+		dev_err(hba->dev,
+		"%s: invalid ref_clk setting = %u\n",
+		__func__, hba->dev_ref_clk_freq);
+		hba->dev_ref_clk_freq = 0;
+	}
+}
+
+static int ufshcd_set_dev_ref_clk(struct ufs_hba *hba)
+{
+	int err = 0;
+	int ref_clk = -1;
+	static const char * const ref_clk_freqs[] = {"19.2 MHz", "26 MHz",
+						     "38.4 MHz", "52 MHz"};
+
+	err = ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_READ_ATTR,
+			QUERY_ATTR_IDN_REF_CLK_FREQ, 0, 0, &ref_clk);
+
+	if (err) {
+		dev_err(hba->dev, "%s: failed reading bRefClkFreq. err = %d\n",
+			 __func__, err);
+		goto out;
+	}
+
+	switch (hba->dev_ref_clk_freq) {
+	case REF_CLK_FREQ_19_2_MHZ:
+		hba->dev_ref_clk_freq = 0x0;
+		break;
+	case REF_CLK_FREQ_26_MHZ:
+		hba->dev_ref_clk_freq = 0x1;
+		break;
+	case REF_CLK_FREQ_38_4_MHZ:
+		hba->dev_ref_clk_freq = 0x2;
+		break;
+	case REF_CLK_FREQ_52_MHZ:
+		hba->dev_ref_clk_freq = 0x3;
+		break;
+	default:
+		dev_err(hba->dev,
+		"%s: invalid ref_clk setting = %u\n",
+		__func__, hba->dev_ref_clk_freq);
+		goto out;
+	}
+
+	if (ref_clk == hba->dev_ref_clk_freq)
+		goto out; /* nothing to update */
+
+	err = ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
+			QUERY_ATTR_IDN_REF_CLK_FREQ, 0, 0,
+			&hba->dev_ref_clk_freq);
+
+	if (err)
+		dev_err(hba->dev, "%s: bRefClkFreq setting to %s failed\n",
+			__func__, ref_clk_freqs[hba->dev_ref_clk_freq]);
+	/*
+	 * It is good to print this out here to debug any later failures
+	 * related to gear switch.
+	 */
+	dev_dbg(hba->dev, "%s: bRefClkFreq setting to %s succeeded\n",
+			__func__, ref_clk_freqs[hba->dev_ref_clk_freq]);
+
+out:
+	return err;
+}
+
 /**
  * ufshcd_probe_hba - probe hba to detect device and initialize
  * @hba: per-adapter instance
@@ -6361,6 +6439,12 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
 			"%s: Failed getting max supported power mode\n",
 			__func__);
 	} else {
+		/*
+		 * Set the right value to bRefClkFreq before attempting to
+		 * switch to HS gears.
+		 */
+		if (hba->dev_ref_clk_freq)
+			ufshcd_set_dev_ref_clk(hba);
 		ret = ufshcd_config_pwr_mode(hba, &hba->max_pwr_info.info);
 		if (ret) {
 			dev_err(hba->dev, "%s: Failed setting power mode, err = %d\n",
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 8110dcd..101a75c 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -548,6 +548,7 @@ struct ufs_hba {
 	void *priv;
 	unsigned int irq;
 	bool is_irq_enabled;
+	u32 dev_ref_clk_freq;
 
 	/* Interrupt aggregation support is broken */
 	#define UFSHCD_QUIRK_BROKEN_INTR_AGGR			0x1
@@ -746,6 +747,7 @@ static inline void ufshcd_rmwl(struct ufs_hba *hba, u32 mask, u32 val, u32 reg)
 int ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask,
 				u32 val, unsigned long interval_us,
 				unsigned long timeout_ms, bool can_sleep);
+void ufshcd_parse_dev_ref_clk_freq(struct ufs_hba *hba);
 
 static inline void check_upiu_size(void)
 {
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH V7 1/2] scsi: ufs: set the device reference clock setting

[Evan Green]

Hi Sayali,

On Wed, Aug 1, 2018 at 1:49 AM Sayali Lokhande <sayalil@codeaurora.org> wrote:
>
> From: Subhash Jadavani <subhashj@codeaurora.org>
>
> UFS host supplies the reference clock to UFS device and UFS device
> specification allows host to provide one of the 4 frequencies (19.2 MHz,
> 26 MHz, 38.4 MHz, 52 MHz) for reference clock. Host should set the
> device reference clock frequency setting in the device based on what
> frequency it is supplying to UFS device.
>
> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
> Signed-off-by: Can Guo <cang@codeaurora.org>
> Signed-off-by: Sayali Lokhande <sayalil@codeaurora.org>
> ---
>  drivers/scsi/ufs/ufs.h           |  8 ++++
>  drivers/scsi/ufs/ufshcd-pltfrm.c |  2 +
>  drivers/scsi/ufs/ufshcd.c        | 84 ++++++++++++++++++++++++++++++++++++++++
>  drivers/scsi/ufs/ufshcd.h        |  2 +
>  4 files changed, 96 insertions(+)
>
> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
> index 14e5bf7..89e0a33 100644
> --- a/drivers/scsi/ufs/ufs.h
> +++ b/drivers/scsi/ufs/ufs.h
> @@ -378,6 +378,14 @@ enum query_opcode {
>         UPIU_QUERY_OPCODE_TOGGLE_FLAG   = 0x8,
>  };
>
> +/* bRefClkFreq attribute values */
> +enum ref_clk_freq {
> +       REF_CLK_FREQ_19_2_MHZ   = 19200000,
> +       REF_CLK_FREQ_26_MHZ     = 26000000,
> +       REF_CLK_FREQ_38_4_MHZ   = 38400000,
> +       REF_CLK_FREQ_52_MHZ     = 52000000,
> +};
> +
>  /* Query response result code */
>  enum {
>         QUERY_RESULT_SUCCESS                    = 0x00,
> diff --git a/drivers/scsi/ufs/ufshcd-pltfrm.c b/drivers/scsi/ufs/ufshcd-pltfrm.c
> index e82bde0..0953563 100644
> --- a/drivers/scsi/ufs/ufshcd-pltfrm.c
> +++ b/drivers/scsi/ufs/ufshcd-pltfrm.c
> @@ -343,6 +343,8 @@ int ufshcd_pltfrm_init(struct platform_device *pdev,
>         pm_runtime_set_active(&pdev->dev);
>         pm_runtime_enable(&pdev->dev);
>
> +       ufshcd_parse_dev_ref_clk_freq(hba);
> +
>         ufshcd_init_lanes_per_dir(hba);
>
>         err = ufshcd_init(hba, mmio_base, irq);
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index c5b1bf1..619313b 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -6296,6 +6296,84 @@ static void ufshcd_def_desc_sizes(struct ufs_hba *hba)
>         hba->desc_size.hlth_desc = QUERY_DESC_HEALTH_DEF_SIZE;
>  }
>
> +void ufshcd_parse_dev_ref_clk_freq(struct ufs_hba *hba)
> +{
> +       struct device *dev = hba->dev;
> +       struct device_node *np = dev->of_node;
> +       struct clk *refclk = NULL;
> +
> +       if (!np)
> +               return;
> +
> +       refclk = of_clk_get_by_name(np, "ref_clk");
> +       if (refclk)
> +               hba->dev_ref_clk_freq  = clk_get_rate(refclk);
> +       else if (!refclk ||
> +               (hba->dev_ref_clk_freq > REF_CLK_FREQ_52_MHZ)) {

What is this logic? The !refclk condition will always be true since
you're in the else case of if (refclk). Also, even if the second part
were executed somehow, you haven't assigned dev_ref_clk_freq yet, so
how can its value be anything other than 0? Maybe that whole
conditional was just not supposed to be an "else" at all, but a
standalone if?

> +               dev_err(hba->dev,
> +               "%s: invalid ref_clk setting = %u\n",
> +               __func__, hba->dev_ref_clk_freq);

There's probably no need to complain if the clock simply couldn't be
found, only if an unexpected value was found.

> +               hba->dev_ref_clk_freq = 0;
> +       }
> +}
> +
> +static int ufshcd_set_dev_ref_clk(struct ufs_hba *hba)
> +{
> +       int err = 0;
> +       int ref_clk = -1;
> +       static const char * const ref_clk_freqs[] = {"19.2 MHz", "26 MHz",
> +                                                    "38.4 MHz", "52 MHz"};
> +
> +       err = ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_READ_ATTR,
> +                       QUERY_ATTR_IDN_REF_CLK_FREQ, 0, 0, &ref_clk);
> +
> +       if (err) {
> +               dev_err(hba->dev, "%s: failed reading bRefClkFreq. err = %d\n",
> +                        __func__, err);
> +               goto out;
> +       }
> +
> +       switch (hba->dev_ref_clk_freq) {
> +       case REF_CLK_FREQ_19_2_MHZ:
> +               hba->dev_ref_clk_freq = 0x0;
> +               break;
> +       case REF_CLK_FREQ_26_MHZ:
> +               hba->dev_ref_clk_freq = 0x1;
> +               break;
> +       case REF_CLK_FREQ_38_4_MHZ:
> +               hba->dev_ref_clk_freq = 0x2;
> +               break;
> +       case REF_CLK_FREQ_52_MHZ:
> +               hba->dev_ref_clk_freq = 0x3;
> +               break;
> +       default:
> +               dev_err(hba->dev,
> +               "%s: invalid ref_clk setting = %u\n",
> +               __func__, hba->dev_ref_clk_freq);
> +               goto out;
> +       }

Please don't assign two different things (frequency in Hertz and
bref_clk value) into the same structure member.

I think rather than having this switch statement you should iterate
through a table that contains elements of {freq_hz, bref_clk, string}.
I think you should do this up in ufshcd_parse_dev_ref_clk_freq so that
you don't have to redo that calculation on every rescan. Then store
the final bRefClkFreq value (or -1 if no definitive answer could be
reached) in your new structure member. Then all this function does is
1) Nothing if dev_ref_clk_freq is -1, or 2) read and maybe write the
attribute.

> +
> +       if (ref_clk == hba->dev_ref_clk_freq)
> +               goto out; /* nothing to update */
> +
> +       err = ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
> +                       QUERY_ATTR_IDN_REF_CLK_FREQ, 0, 0,
> +                       &hba->dev_ref_clk_freq);
> +
> +       if (err)
> +               dev_err(hba->dev, "%s: bRefClkFreq setting to %s failed\n",
> +                       __func__, ref_clk_freqs[hba->dev_ref_clk_freq]);
> +       /*
> +        * It is good to print this out here to debug any later failures
> +        * related to gear switch.
> +        */
> +       dev_dbg(hba->dev, "%s: bRefClkFreq setting to %s succeeded\n",
> +                       __func__, ref_clk_freqs[hba->dev_ref_clk_freq]);
> +
> +out:
> +       return err;
> +}
> +
>  /**
>   * ufshcd_probe_hba - probe hba to detect device and initialize
>   * @hba: per-adapter instance
> @@ -6361,6 +6439,12 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
>                         "%s: Failed getting max supported power mode\n",
>                         __func__);
>         } else {
> +               /*
> +                * Set the right value to bRefClkFreq before attempting to
> +                * switch to HS gears.
> +                */
> +               if (hba->dev_ref_clk_freq)
> +                       ufshcd_set_dev_ref_clk(hba);
>                 ret = ufshcd_config_pwr_mode(hba, &hba->max_pwr_info.info);
>                 if (ret) {
>                         dev_err(hba->dev, "%s: Failed setting power mode, err = %d\n",
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 8110dcd..101a75c 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -548,6 +548,7 @@ struct ufs_hba {
>         void *priv;
>         unsigned int irq;
>         bool is_irq_enabled;
> +       u32 dev_ref_clk_freq;

If you followed my suggestion of this storing _only_ the bRefClkFreq
value or -1 if unset, then this would need to be signed, and
initialized somewhere so that 0 wasn't accidentally taken to be a
parsed value.

>
>         /* Interrupt aggregation support is broken */
>         #define UFSHCD_QUIRK_BROKEN_INTR_AGGR                   0x1
> @@ -746,6 +747,7 @@ static inline void ufshcd_rmwl(struct ufs_hba *hba, u32 mask, u32 val, u32 reg)
>  int ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask,
>                                 u32 val, unsigned long interval_us,
>                                 unsigned long timeout_ms, bool can_sleep);
> +void ufshcd_parse_dev_ref_clk_freq(struct ufs_hba *hba);
>
>  static inline void check_upiu_size(void)
>  {
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>

Re: [PATCH V7 1/2] scsi: ufs: set the device reference clock setting

[Sayali Lokhande]

Hi Evan,

On 8/6/2018 10:56 PM, Evan Green wrote:
> Hi Sayali,
>
> On Wed, Aug 1, 2018 at 1:49 AM Sayali Lokhande <sayalil@codeaurora.org> wrote:
>> From: Subhash Jadavani <subhashj@codeaurora.org>
>>
>> UFS host supplies the reference clock to UFS device and UFS device
>> specification allows host to provide one of the 4 frequencies (19.2 MHz,
>> 26 MHz, 38.4 MHz, 52 MHz) for reference clock. Host should set the
>> device reference clock frequency setting in the device based on what
>> frequency it is supplying to UFS device.
>>
>> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
>> Signed-off-by: Can Guo <cang@codeaurora.org>
>> Signed-off-by: Sayali Lokhande <sayalil@codeaurora.org>
>> ---
>>   drivers/scsi/ufs/ufs.h           |  8 ++++
>>   drivers/scsi/ufs/ufshcd-pltfrm.c |  2 +
>>   drivers/scsi/ufs/ufshcd.c        | 84 ++++++++++++++++++++++++++++++++++++++++
>>   drivers/scsi/ufs/ufshcd.h        |  2 +
>>   4 files changed, 96 insertions(+)
>>
>> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
>> index 14e5bf7..89e0a33 100644
>> --- a/drivers/scsi/ufs/ufs.h
>> +++ b/drivers/scsi/ufs/ufs.h
>> @@ -378,6 +378,14 @@ enum query_opcode {
>>          UPIU_QUERY_OPCODE_TOGGLE_FLAG   = 0x8,
>>   };
>>
>> +/* bRefClkFreq attribute values */
>> +enum ref_clk_freq {
>> +       REF_CLK_FREQ_19_2_MHZ   = 19200000,
>> +       REF_CLK_FREQ_26_MHZ     = 26000000,
>> +       REF_CLK_FREQ_38_4_MHZ   = 38400000,
>> +       REF_CLK_FREQ_52_MHZ     = 52000000,
>> +};
>> +
>>   /* Query response result code */
>>   enum {
>>          QUERY_RESULT_SUCCESS                    = 0x00,
>> diff --git a/drivers/scsi/ufs/ufshcd-pltfrm.c b/drivers/scsi/ufs/ufshcd-pltfrm.c
>> index e82bde0..0953563 100644
>> --- a/drivers/scsi/ufs/ufshcd-pltfrm.c
>> +++ b/drivers/scsi/ufs/ufshcd-pltfrm.c
>> @@ -343,6 +343,8 @@ int ufshcd_pltfrm_init(struct platform_device *pdev,
>>          pm_runtime_set_active(&pdev->dev);
>>          pm_runtime_enable(&pdev->dev);
>>
>> +       ufshcd_parse_dev_ref_clk_freq(hba);
>> +
>>          ufshcd_init_lanes_per_dir(hba);
>>
>>          err = ufshcd_init(hba, mmio_base, irq);
>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> index c5b1bf1..619313b 100644
>> --- a/drivers/scsi/ufs/ufshcd.c
>> +++ b/drivers/scsi/ufs/ufshcd.c
>> @@ -6296,6 +6296,84 @@ static void ufshcd_def_desc_sizes(struct ufs_hba *hba)
>>          hba->desc_size.hlth_desc = QUERY_DESC_HEALTH_DEF_SIZE;
>>   }
>>
>> +void ufshcd_parse_dev_ref_clk_freq(struct ufs_hba *hba)
>> +{
>> +       struct device *dev = hba->dev;
>> +       struct device_node *np = dev->of_node;
>> +       struct clk *refclk = NULL;
>> +
>> +       if (!np)
>> +               return;
>> +
>> +       refclk = of_clk_get_by_name(np, "ref_clk");
>> +       if (refclk)
>> +               hba->dev_ref_clk_freq  = clk_get_rate(refclk);
>> +       else if (!refclk ||
>> +               (hba->dev_ref_clk_freq > REF_CLK_FREQ_52_MHZ)) {
> What is this logic? The !refclk condition will always be true since
> you're in the else case of if (refclk). Also, even if the second part
> were executed somehow, you haven't assigned dev_ref_clk_freq yet, so
> how can its value be anything other than 0? Maybe that whole
> conditional was just not supposed to be an "else" at all, but a
> standalone if?
Agree. Will update.
>> +               dev_err(hba->dev,
>> +               "%s: invalid ref_clk setting = %u\n",
>> +               __func__, hba->dev_ref_clk_freq);
> There's probably no need to complain if the clock simply couldn't be
> found, only if an unexpected value was found.
Agree. Will update.
>> +               hba->dev_ref_clk_freq = 0;
>> +       }
>> +}
>> +
>> +static int ufshcd_set_dev_ref_clk(struct ufs_hba *hba)
>> +{
>> +       int err = 0;
>> +       int ref_clk = -1;
>> +       static const char * const ref_clk_freqs[] = {"19.2 MHz", "26 MHz",
>> +                                                    "38.4 MHz", "52 MHz"};
>> +
>> +       err = ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_READ_ATTR,
>> +                       QUERY_ATTR_IDN_REF_CLK_FREQ, 0, 0, &ref_clk);
>> +
>> +       if (err) {
>> +               dev_err(hba->dev, "%s: failed reading bRefClkFreq. err = %d\n",
>> +                        __func__, err);
>> +               goto out;
>> +       }
>> +
>> +       switch (hba->dev_ref_clk_freq) {
>> +       case REF_CLK_FREQ_19_2_MHZ:
>> +               hba->dev_ref_clk_freq = 0x0;
>> +               break;
>> +       case REF_CLK_FREQ_26_MHZ:
>> +               hba->dev_ref_clk_freq = 0x1;
>> +               break;
>> +       case REF_CLK_FREQ_38_4_MHZ:
>> +               hba->dev_ref_clk_freq = 0x2;
>> +               break;
>> +       case REF_CLK_FREQ_52_MHZ:
>> +               hba->dev_ref_clk_freq = 0x3;
>> +               break;
>> +       default:
>> +               dev_err(hba->dev,
>> +               "%s: invalid ref_clk setting = %u\n",
>> +               __func__, hba->dev_ref_clk_freq);
>> +               goto out;
>> +       }
> Please don't assign two different things (frequency in Hertz and
> bref_clk value) into the same structure member.
>
> I think rather than having this switch statement you should iterate
> through a table that contains elements of {freq_hz, bref_clk, string}.
> I think you should do this up in ufshcd_parse_dev_ref_clk_freq so that
> you don't have to redo that calculation on every rescan. Then store
> the final bRefClkFreq value (or -1 if no definitive answer could be
> reached) in your new structure member. Then all this function does is
> 1) Nothing if dev_ref_clk_freq is -1, or 2) read and maybe write the
> attribute.
Agree. Will update.
>> +
>> +       if (ref_clk == hba->dev_ref_clk_freq)
>> +               goto out; /* nothing to update */
>> +
>> +       err = ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
>> +                       QUERY_ATTR_IDN_REF_CLK_FREQ, 0, 0,
>> +                       &hba->dev_ref_clk_freq);
>> +
>> +       if (err)
>> +               dev_err(hba->dev, "%s: bRefClkFreq setting to %s failed\n",
>> +                       __func__, ref_clk_freqs[hba->dev_ref_clk_freq]);
>> +       /*
>> +        * It is good to print this out here to debug any later failures
>> +        * related to gear switch.
>> +        */
>> +       dev_dbg(hba->dev, "%s: bRefClkFreq setting to %s succeeded\n",
>> +                       __func__, ref_clk_freqs[hba->dev_ref_clk_freq]);
>> +
>> +out:
>> +       return err;
>> +}
>> +
>>   /**
>>    * ufshcd_probe_hba - probe hba to detect device and initialize
>>    * @hba: per-adapter instance
>> @@ -6361,6 +6439,12 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
>>                          "%s: Failed getting max supported power mode\n",
>>                          __func__);
>>          } else {
>> +               /*
>> +                * Set the right value to bRefClkFreq before attempting to
>> +                * switch to HS gears.
>> +                */
>> +               if (hba->dev_ref_clk_freq)
>> +                       ufshcd_set_dev_ref_clk(hba);
>>                  ret = ufshcd_config_pwr_mode(hba, &hba->max_pwr_info.info);
>>                  if (ret) {
>>                          dev_err(hba->dev, "%s: Failed setting power mode, err = %d\n",
>> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
>> index 8110dcd..101a75c 100644
>> --- a/drivers/scsi/ufs/ufshcd.h
>> +++ b/drivers/scsi/ufs/ufshcd.h
>> @@ -548,6 +548,7 @@ struct ufs_hba {
>>          void *priv;
>>          unsigned int irq;
>>          bool is_irq_enabled;
>> +       u32 dev_ref_clk_freq;
> If you followed my suggestion of this storing _only_ the bRefClkFreq
> value or -1 if unset, then this would need to be signed, and
> initialized somewhere so that 0 wasn't accidentally taken to be a
> parsed value.
Will check and update (if necessary).
>>          /* Interrupt aggregation support is broken */
>>          #define UFSHCD_QUIRK_BROKEN_INTR_AGGR                   0x1
>> @@ -746,6 +747,7 @@ static inline void ufshcd_rmwl(struct ufs_hba *hba, u32 mask, u32 val, u32 reg)
>>   int ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask,
>>                                  u32 val, unsigned long interval_us,
>>                                  unsigned long timeout_ms, bool can_sleep);
>> +void ufshcd_parse_dev_ref_clk_freq(struct ufs_hba *hba);
>>
>>   static inline void check_upiu_size(void)
>>   {
>> --
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
>> a Linux Foundation Collaborative Project
>>

[PATCH V7 2/2] scsi: ufs: Add configfs support for UFS provisioning

[Sayali Lokhande]

This patch adds configfs support to provision UFS device at
runtime. This feature can be primarily useful in factory or
assembly line as some devices may be required to be configured
multiple times during initial system development phase.
Configuration Descriptors can be written multiple times until
bConfigDescrLock attribute is zero.

Configuration descriptor buffer consists of Device and Unit
descriptor configurable parameters which are parsed from vendor
specific provisioning file and then passed via configfs node at
runtime to provision ufs device.
CONFIG_CONFIGFS_FS needs to be enabled for using this feature.

Usage:
1) To read current configuration descriptor :
   cat /config/XXXX.ufshc/ufs_provision
2) To provision ufs device:
   echo <config_desc_buf> > /config/XXXX.ufshc/ufs_provision

Signed-off-by: Sayali Lokhande <sayalil@codeaurora.org>
---
 Documentation/ABI/testing/configfs-driver-ufs |  18 +++
 drivers/scsi/ufs/Kconfig                      |  10 ++
 drivers/scsi/ufs/Makefile                     |   1 +
 drivers/scsi/ufs/ufs-configfs.c               | 162 ++++++++++++++++++++++++++
 drivers/scsi/ufs/ufshcd.c                     |   7 +-
 drivers/scsi/ufs/ufshcd.h                     |  10 ++
 6 files changed, 207 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/ABI/testing/configfs-driver-ufs
 create mode 100644 drivers/scsi/ufs/ufs-configfs.c

diff --git a/Documentation/ABI/testing/configfs-driver-ufs b/Documentation/ABI/testing/configfs-driver-ufs
new file mode 100644
index 0000000..eeee499c
--- /dev/null
+++ b/Documentation/ABI/testing/configfs-driver-ufs
@@ -0,0 +1,18 @@
+What:		/config/ufshcd/ufs_provision
+Date:		Jun 2018
+KernelVersion:	4.14
+Description:
+		This file shows the current ufs configuration descriptor set in device.
+		This can be used to provision ufs device if bConfigDescrLock is 0.
+		For more details, refer 14.1.6.3 Configuration Descriptor and
+		Table 14-12 - Unit Descriptor configurable parameters from specs for
+		description of each configuration descriptor parameter.
+		Configuration descriptor buffer needs to be passed in space separated
+		format specificied as below:
+		echo <bLength> <bDescriptorIDN> <bConfDescContinue> <bBootEnable>
+		<bDescrAccessEn> <bInitPowerMode> <bHighPriorityLUN>
+		<bSecureRemovalType> <bInitActiveICCLevel> <wPeriodicRTCUpdate>
+		<0Bh:0Fh_ReservedAs_0> <bLUEnable> <bBootLunID> <bLUWriteProtect>
+		<bMemoryType> <dNumAllocUnits> <bDataReliability> <bLogicalBlockSize>
+		<bProvisioningType> <wContextCapabilities> <0Dh:0Fh_ReservedAs_0>
+		> /config/XXXX.ufshc/ufs_provision
diff --git a/drivers/scsi/ufs/Kconfig b/drivers/scsi/ufs/Kconfig
index e27b4d4..a9a0a58 100644
--- a/drivers/scsi/ufs/Kconfig
+++ b/drivers/scsi/ufs/Kconfig
@@ -100,3 +100,13 @@ config SCSI_UFS_QCOM
 
 	  Select this if you have UFS controller on QCOM chipset.
 	  If unsure, say N.
+
+config UFS_PROVISION
+	tristate "Runtime UFS Provisioning support"
+	depends on SCSI_UFSHCD && CONFIGFS_FS
+	help
+	  This enables runtime UFS provisioning support. This can be used
+	  primarily during assembly line as some devices may be required to
+	  be configured multiple times during initial development phase.
+
+	  If unsure, say N.
diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile
index 918f579..00110ea 100644
--- a/drivers/scsi/ufs/Makefile
+++ b/drivers/scsi/ufs/Makefile
@@ -5,5 +5,6 @@ obj-$(CONFIG_SCSI_UFS_DWC_TC_PLATFORM) += tc-dwc-g210-pltfrm.o ufshcd-dwc.o tc-d
 obj-$(CONFIG_SCSI_UFS_QCOM) += ufs-qcom.o
 obj-$(CONFIG_SCSI_UFSHCD) += ufshcd-core.o
 ufshcd-core-objs := ufshcd.o ufs-sysfs.o
+obj-$(CONFIG_UFS_PROVISION) += ufs-configfs.o
 obj-$(CONFIG_SCSI_UFSHCD_PCI) += ufshcd-pci.o
 obj-$(CONFIG_SCSI_UFSHCD_PLATFORM) += ufshcd-pltfrm.o
diff --git a/drivers/scsi/ufs/ufs-configfs.c b/drivers/scsi/ufs/ufs-configfs.c
new file mode 100644
index 0000000..f164967
--- /dev/null
+++ b/drivers/scsi/ufs/ufs-configfs.c
@@ -0,0 +1,162 @@
+// SPDX-License-Identifier: GPL-2.0+
+// Copyright (c) 2018, Linux Foundation.
+
+#include <linux/configfs.h>
+#include <linux/err.h>
+#include <linux/string.h>
+
+#include "ufs.h"
+#include "ufshcd.h"
+
+static inline struct ufs_hba *config_item_to_hba(struct config_item *item)
+{
+	struct config_group *group = to_config_group(item);
+	struct configfs_subsystem *subsys = to_configfs_subsystem(group);
+	struct ufs_hba *hba = container_of(subsys, struct ufs_hba, subsys);
+
+	return hba ? hba : NULL;
+}
+
+static ssize_t ufs_provision_show(struct config_item *item, char *buf)
+{
+	u8 desc_buf[QUERY_DESC_CONFIGURATION_DEF_SIZE] = {0};
+	int buff_len = QUERY_DESC_CONFIGURATION_DEF_SIZE;
+	int i, ret, curr_len = 0;
+	struct ufs_hba *hba = config_item_to_hba(item);
+
+	if (!hba)
+		return snprintf(buf, PAGE_SIZE, "ufs hba is NULL!\n");
+
+	ret = ufshcd_query_descriptor_retry(hba, UPIU_QUERY_OPCODE_READ_DESC,
+		QUERY_DESC_IDN_CONFIGURATION, 0, 0, desc_buf, &buff_len);
+
+	if (ret)
+		return snprintf(buf, PAGE_SIZE,
+		"Failed reading descriptor. desc_idn %d, opcode %x ret %d\n",
+		QUERY_DESC_IDN_CONFIGURATION,
+		UPIU_QUERY_OPCODE_READ_DESC, ret);
+
+	for (i = 0; i < buff_len; i++)
+		curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
+				"0x%x ", desc_buf[i]);
+
+	return curr_len;
+}
+
+ssize_t ufshcd_desc_configfs_store(struct ufs_hba *hba,
+		const char *buf, size_t count)
+{
+	char *strbuf;
+	char *strbuf_copy;
+	u8 desc_buf[QUERY_DESC_CONFIGURATION_DEF_SIZE] = {0};
+	int buff_len = QUERY_DESC_CONFIGURATION_DEF_SIZE;
+	char *token;
+	int i, ret, value;
+	u32 bConfigDescrLock = 0;
+
+	/* reserve one byte for null termination */
+	strbuf = kmalloc(count + 1, GFP_KERNEL);
+	if (!strbuf)
+		return -ENOMEM;
+
+	strbuf_copy = strbuf;
+	strlcpy(strbuf, buf, count + 1);
+
+	if (!hba)
+		goto out;
+
+	/* Just return if bConfigDescrLock is already set */
+	ret = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,
+		QUERY_ATTR_IDN_CONF_DESC_LOCK, 0, 0, &bConfigDescrLock);
+	if (ret)
+		goto out;
+
+	if (bConfigDescrLock) {
+		dev_err(hba->dev, "%s: bConfigDescrLock already set to %u, cannot re-provision device!\n",
+		__func__, bConfigDescrLock);
+		goto out;
+	}
+
+	for (i = 0; i < QUERY_DESC_CONFIGURATION_DEF_SIZE; i++) {
+		token = strsep(&strbuf, " ");
+		if (!token && i)
+			break;
+
+		ret = kstrtoint(token, 0, &value);
+		if (ret) {
+			dev_err(hba->dev, "%s: kstrtoint failed %d %s\n",
+				__func__, ret, token);
+			goto out;
+		}
+		desc_buf[i] = (u8)value;
+	}
+
+	/* Write configuration descriptor to provision ufs */
+	ret = ufshcd_query_descriptor_retry(hba, UPIU_QUERY_OPCODE_WRITE_DESC,
+		QUERY_DESC_IDN_CONFIGURATION, 0, 0, desc_buf, &buff_len);
+
+	if (!ret)
+		dev_err(hba->dev, "%s: UFS Provisioning done, reboot now!\n",
+		__func__);
+
+out:
+	kfree(strbuf_copy);
+	return count;
+}
+
+static ssize_t ufs_provision_store(struct config_item *item,
+		const char *buf, size_t count)
+{
+	struct ufs_hba *hba = config_item_to_hba(item);
+
+	return ufshcd_desc_configfs_store(hba, buf, count);
+}
+
+static struct configfs_attribute ufshcd_attr_provision = {
+	.ca_name	= "ufs_provision",
+	.ca_mode	= 0644,
+	.ca_owner	= THIS_MODULE,
+	.show		= ufs_provision_show,
+	.store		= ufs_provision_store,
+};
+
+static struct configfs_attribute *ufshcd_attrs[] = {
+	&ufshcd_attr_provision,
+	NULL,
+};
+
+static struct config_item_type ufscfg_type = {
+	.ct_attrs	= ufshcd_attrs,
+	.ct_owner	= THIS_MODULE,
+};
+
+static struct configfs_subsystem ufscfg_subsys = {
+	.su_group = {
+		.cg_item = {
+			.ci_type = &ufscfg_type,
+		},
+	},
+};
+
+int ufshcd_configfs_init(struct ufs_hba *hba, const char *name)
+{
+	int ret;
+	struct configfs_subsystem *subsys = &hba->subsys;
+
+	strncpy(ufscfg_subsys.su_group.cg_item.ci_namebuf, name, strlen(name));
+	subsys->su_group = ufscfg_subsys.su_group;
+	config_group_init(&subsys->su_group);
+	mutex_init(&subsys->su_mutex);
+	ret = configfs_register_subsystem(subsys);
+	if (ret)
+		pr_err("Error %d while registering subsystem %s\n",
+		       ret,
+		       subsys->su_group.cg_item.ci_namebuf);
+
+	return ret;
+}
+
+void ufshcd_configfs_exit(void)
+{
+	configfs_unregister_subsystem(&ufscfg_subsys);
+}
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 619313b..9101d71 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -7706,6 +7706,9 @@ int ufshcd_shutdown(struct ufs_hba *hba)
 void ufshcd_remove(struct ufs_hba *hba)
 {
 	ufs_sysfs_remove_nodes(hba->dev);
+#ifdef CONFIG_UFS_PROVISION
+	ufshcd_configfs_exit();
+#endif
 	scsi_remove_host(hba->host);
 	/* disable interrupts */
 	ufshcd_disable_intr(hba, hba->intr_mask);
@@ -7959,7 +7962,9 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
 
 	async_schedule(ufshcd_async_scan, hba);
 	ufs_sysfs_add_nodes(hba->dev);
-
+#ifdef CONFIG_UFS_PROVISION
+	ufshcd_configfs_init(hba, dev_name(hba->dev));
+#endif
 	return 0;
 
 out_remove_scsi_host:
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 101a75c..7b6cc88 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -37,6 +37,7 @@
 #ifndef _UFSHCD_H
 #define _UFSHCD_H
 
+#include <linux/configfs.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
@@ -515,6 +516,9 @@ struct ufs_hba {
 
 	struct Scsi_Host *host;
 	struct device *dev;
+#ifdef CONFIG_UFS_PROVISION
+	struct configfs_subsystem subsys;
+#endif
 	/*
 	 * This field is to keep a reference to "scsi_device" corresponding to
 	 * "UFS device" W-LU.
@@ -868,6 +872,12 @@ int ufshcd_read_string_desc(struct ufs_hba *hba, int desc_index,
 int ufshcd_hold(struct ufs_hba *hba, bool async);
 void ufshcd_release(struct ufs_hba *hba);
 
+/* Expose UFS configfs API's */
+#ifdef CONFIG_UFS_PROVISION
+extern int ufshcd_configfs_init(struct ufs_hba *hba, const char *name);
+extern void ufshcd_configfs_exit(void);
+#endif
+
 int ufshcd_map_desc_id_to_length(struct ufs_hba *hba, enum desc_idn desc_id,
 	int *desc_length);
 
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH V7 2/2] scsi: ufs: Add configfs support for UFS provisioning

[Evan Green]

Hi Sayali,

On Wed, Aug 1, 2018 at 1:49 AM Sayali Lokhande <sayalil@codeaurora.org> wrote:
>
> This patch adds configfs support to provision UFS device at
> runtime. This feature can be primarily useful in factory or
> assembly line as some devices may be required to be configured
> multiple times during initial system development phase.
> Configuration Descriptors can be written multiple times until
> bConfigDescrLock attribute is zero.
>
> Configuration descriptor buffer consists of Device and Unit
> descriptor configurable parameters which are parsed from vendor
> specific provisioning file and then passed via configfs node at
> runtime to provision ufs device.
> CONFIG_CONFIGFS_FS needs to be enabled for using this feature.
>
> Usage:
> 1) To read current configuration descriptor :
>    cat /config/XXXX.ufshc/ufs_provision
> 2) To provision ufs device:
>    echo <config_desc_buf> > /config/XXXX.ufshc/ufs_provision
>
> Signed-off-by: Sayali Lokhande <sayalil@codeaurora.org>
> ---
>  Documentation/ABI/testing/configfs-driver-ufs |  18 +++
>  drivers/scsi/ufs/Kconfig                      |  10 ++
>  drivers/scsi/ufs/Makefile                     |   1 +
>  drivers/scsi/ufs/ufs-configfs.c               | 162 ++++++++++++++++++++++++++
>  drivers/scsi/ufs/ufshcd.c                     |   7 +-
>  drivers/scsi/ufs/ufshcd.h                     |  10 ++
>  6 files changed, 207 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/ABI/testing/configfs-driver-ufs
>  create mode 100644 drivers/scsi/ufs/ufs-configfs.c
>

You didn't address any of my feedback from V6. All of that still applies.
-Evan