2024-05-06 17:01:47

by Sean Anderson

[permalink] [raw]
Subject: [PATCH v2 0/4] phy: zynqmp: Fixes and debugfs support

This has a few fixes and cleanups cleaning up the driver. Additionally,
the last patch adds useful debugfs info.

Changes in v2:
- Enable reference clock correctly
- Expand the icm_matrix comment
- Move the logic for waiting on PLL lock to xpsgtr_wait_pll_lock
- Use debugfs_create_devm_seqfile

Sean Anderson (4):
phy: zynqmp: Enable reference clock correctly
phy: zynqmp: Store instance instead of type
phy: zynqmp: Only wait for PLL lock "primary" instances
phy: zynqmp: Add debugfs support

drivers/phy/xilinx/phy-zynqmp.c | 197 ++++++++++++++++----------------
1 file changed, 100 insertions(+), 97 deletions(-)

--
2.35.1.1320.gc452695387.dirty



2024-05-06 17:02:01

by Sean Anderson

[permalink] [raw]
Subject: [PATCH v2 3/4] phy: zynqmp: Only wait for PLL lock "primary" instances

For PCIe and DisplayPort, the phy instance represents the controller's
logical lane. Wait for the instance 0 phy's PLL to lock as other
instances will never lock. We do this in xpsgtr_wait_pll_lock so callers
don't have to determine the correct lane themselves.

The original comment is wrong about cumulative wait times. Since we are
just polling a bit, all subsequent waiters will finish immediately.

Signed-off-by: Sean Anderson <[email protected]>
---

Changes in v2:
- Move the logic for waiting on PLL lock to xpsgtr_wait_pll_lock

drivers/phy/xilinx/phy-zynqmp.c | 30 +++++++++++++++++++++---------
1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/drivers/phy/xilinx/phy-zynqmp.c b/drivers/phy/xilinx/phy-zynqmp.c
index 5a8f81bbeb8d..b86fe2a249a8 100644
--- a/drivers/phy/xilinx/phy-zynqmp.c
+++ b/drivers/phy/xilinx/phy-zynqmp.c
@@ -294,10 +294,30 @@ static int xpsgtr_wait_pll_lock(struct phy *phy)
struct xpsgtr_phy *gtr_phy = phy_get_drvdata(phy);
struct xpsgtr_dev *gtr_dev = gtr_phy->dev;
unsigned int timeout = TIMEOUT_US;
+ u8 protocol = gtr_phy->protocol;
int ret;

dev_dbg(gtr_dev->dev, "Waiting for PLL lock\n");

+ /*
+ * For DP and PCIe, only the instance 0 PLL is used. Switch to that phy
+ * so we wait on the right PLL.
+ */
+ if ((protocol == ICM_PROTOCOL_DP || protocol == ICM_PROTOCOL_PCIE) &&
+ gtr_phy->instance) {
+ int i;
+
+ for (i = 0; i < NUM_LANES; i++) {
+ gtr_phy = &gtr_dev->phys[i];
+
+ if (gtr_phy->protocol == protocol && !gtr_phy->instance)
+ goto got_phy;
+ }
+
+ return -EBUSY;
+ }
+
+got_phy:
while (1) {
u32 reg = xpsgtr_read_phy(gtr_phy, L0_PLL_STATUS_READ_1);

@@ -627,15 +647,7 @@ static int xpsgtr_phy_power_on(struct phy *phy)
/* Skip initialization if not required. */
if (!xpsgtr_phy_init_required(gtr_phy))
return ret;
- /*
- * Wait for the PLL to lock. For DP, only wait on DP0 to avoid
- * cumulating waits for both lanes. The user is expected to initialize
- * lane 0 last.
- */
- if (gtr_phy->protocol != ICM_PROTOCOL_DP || !gtr_phy->instance)
- ret = xpsgtr_wait_pll_lock(phy);
-
- return ret;
+ return xpsgtr_wait_pll_lock(phy);
}

static int xpsgtr_phy_configure(struct phy *phy, union phy_configure_opts *opts)
--
2.35.1.1320.gc452695387.dirty


2024-05-06 17:02:37

by Sean Anderson

[permalink] [raw]
Subject: [PATCH v2 4/4] phy: zynqmp: Add debugfs support

Add support for printing some basic status information to debugfs. This
is helpful when debugging phy consumers to make sure they are configuring
the phy appropriately.

Signed-off-by: Sean Anderson <[email protected]>
---

Changes in v2:
- Use debugfs_create_devm_seqfile

drivers/phy/xilinx/phy-zynqmp.c | 40 +++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)

diff --git a/drivers/phy/xilinx/phy-zynqmp.c b/drivers/phy/xilinx/phy-zynqmp.c
index b86fe2a249a8..2520c75a4a77 100644
--- a/drivers/phy/xilinx/phy-zynqmp.c
+++ b/drivers/phy/xilinx/phy-zynqmp.c
@@ -13,6 +13,7 @@
*/

#include <linux/clk.h>
+#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/kernel.h>
@@ -123,6 +124,15 @@
#define ICM_PROTOCOL_DP 0x4
#define ICM_PROTOCOL_SGMII 0x5

+static const char *const xpsgtr_icm_str[] = {
+ [ICM_PROTOCOL_PD] = "powered down",
+ [ICM_PROTOCOL_PCIE] = "PCIe",
+ [ICM_PROTOCOL_SATA] = "SATA",
+ [ICM_PROTOCOL_USB] = "USB",
+ [ICM_PROTOCOL_DP] = "DisplayPort",
+ [ICM_PROTOCOL_SGMII] = "SGMII",
+};
+
/* Test Mode common reset control parameters */
#define TM_CMN_RST 0x10018
#define TM_CMN_RST_EN 0x1
@@ -788,6 +798,34 @@ static struct phy *xpsgtr_xlate(struct device *dev,
return ERR_PTR(-EINVAL);
}

+/*
+ * DebugFS
+ */
+
+static int xpsgtr_status_read(struct seq_file *seq, void *data)
+{
+ struct device *dev = seq->private;
+ struct xpsgtr_phy *gtr_phy = dev_get_drvdata(dev);
+ struct clk *clk;
+ u32 pll_status;
+
+ mutex_lock(&gtr_phy->phy->mutex);
+ pll_status = xpsgtr_read_phy(gtr_phy, L0_PLL_STATUS_READ_1);
+ clk = gtr_phy->dev->clk[gtr_phy->refclk];
+
+ seq_printf(seq, "Lane: %u\n", gtr_phy->lane);
+ seq_printf(seq, "Protocol: %s\n",
+ xpsgtr_icm_str[gtr_phy->protocol]);
+ seq_printf(seq, "Instance: %u\n", gtr_phy->instance);
+ seq_printf(seq, "Reference clock: %u (%pC)\n", gtr_phy->refclk, clk);
+ seq_printf(seq, "Reference rate: %lu\n", clk_get_rate(clk));
+ seq_printf(seq, "PLL locked: %s\n",
+ pll_status & PLL_STATUS_LOCKED ? "yes" : "no");
+
+ mutex_unlock(&gtr_phy->phy->mutex);
+ return 0;
+}
+
/*
* Power Management
*/
@@ -937,6 +975,8 @@ static int xpsgtr_probe(struct platform_device *pdev)

gtr_phy->phy = phy;
phy_set_drvdata(phy, gtr_phy);
+ debugfs_create_devm_seqfile(&phy->dev, "status", phy->debugfs,
+ xpsgtr_status_read);
}

/* Register the PHY provider. */
--
2.35.1.1320.gc452695387.dirty


2024-06-13 09:21:22

by Pandey, Radhey Shyam

[permalink] [raw]
Subject: RE: [PATCH v2 4/4] phy: zynqmp: Add debugfs support

> -----Original Message-----
> From: Sean Anderson <[email protected]>
> Sent: Monday, May 6, 2024 10:31 PM
> To: Laurent Pinchart <[email protected]>; linux-
> [email protected]
> Cc: Vinod Koul <[email protected]>; [email protected];
> [email protected]; Michal Simek <[email protected]>;
> Kishon Vijay Abraham I <[email protected]>; Sean Anderson
> <[email protected]>
> Subject: [PATCH v2 4/4] phy: zynqmp: Add debugfs support
>
> Add support for printing some basic status information to debugfs. This
> is helpful when debugging phy consumers to make sure they are configuring
> the phy appropriately.
>
> Signed-off-by: Sean Anderson <[email protected]>
> ---
>
> Changes in v2:
> - Use debugfs_create_devm_seqfile
>
> drivers/phy/xilinx/phy-zynqmp.c | 40
> +++++++++++++++++++++++++++++++++
> 1 file changed, 40 insertions(+)
>
> diff --git a/drivers/phy/xilinx/phy-zynqmp.c b/drivers/phy/xilinx/phy-
> zynqmp.c
> index b86fe2a249a8..2520c75a4a77 100644
> --- a/drivers/phy/xilinx/phy-zynqmp.c
> +++ b/drivers/phy/xilinx/phy-zynqmp.c
> @@ -13,6 +13,7 @@
> */
>
> #include <linux/clk.h>
> +#include <linux/debugfs.h>
> #include <linux/delay.h>
> #include <linux/io.h>
> #include <linux/kernel.h>
> @@ -123,6 +124,15 @@
> #define ICM_PROTOCOL_DP 0x4
> #define ICM_PROTOCOL_SGMII 0x5
>
> +static const char *const xpsgtr_icm_str[] = {
> + [ICM_PROTOCOL_PD] = "powered down",

Protocol saying powered down seems confusing.
Should we say None or None(power down)?

> + [ICM_PROTOCOL_PCIE] = "PCIe",
> + [ICM_PROTOCOL_SATA] = "SATA",
> + [ICM_PROTOCOL_USB] = "USB",
> + [ICM_PROTOCOL_DP] = "DisplayPort",
> + [ICM_PROTOCOL_SGMII] = "SGMII",
> +};
> +
> /* Test Mode common reset control parameters */
> #define TM_CMN_RST 0x10018
> #define TM_CMN_RST_EN 0x1
> @@ -788,6 +798,34 @@ static struct phy *xpsgtr_xlate(struct device *dev,
> return ERR_PTR(-EINVAL);
> }
>
> +/*
> + * DebugFS
> + */
> +
> +static int xpsgtr_status_read(struct seq_file *seq, void *data)
> +{
> + struct device *dev = seq->private;
> + struct xpsgtr_phy *gtr_phy = dev_get_drvdata(dev);
> + struct clk *clk;
> + u32 pll_status;
> +
> + mutex_lock(&gtr_phy->phy->mutex);

Do we see any need for this lock? This function simply read hw register
/phy members and decodes it.

> + pll_status = xpsgtr_read_phy(gtr_phy, L0_PLL_STATUS_READ_1);
> + clk = gtr_phy->dev->clk[gtr_phy->refclk];
> +
> + seq_printf(seq, "Lane: %u\n", gtr_phy->lane);
> + seq_printf(seq, "Protocol: %s\n",
> + xpsgtr_icm_str[gtr_phy->protocol]);
> + seq_printf(seq, "Instance: %u\n", gtr_phy->instance);
> + seq_printf(seq, "Reference clock: %u (%pC)\n", gtr_phy->refclk, clk);
> + seq_printf(seq, "Reference rate: %lu\n", clk_get_rate(clk));
> + seq_printf(seq, "PLL locked: %s\n",
> + pll_status & PLL_STATUS_LOCKED ? "yes" : "no");
> +
> + mutex_unlock(&gtr_phy->phy->mutex);
> + return 0;
> +}
> +
> /*
> * Power Management
> */
> @@ -937,6 +975,8 @@ static int xpsgtr_probe(struct platform_device *pdev)
>
> gtr_phy->phy = phy;
> phy_set_drvdata(phy, gtr_phy);
> + debugfs_create_devm_seqfile(&phy->dev, "status", phy-
> >debugfs,
> + xpsgtr_status_read);
> }
>
> /* Register the PHY provider. */
> --
> 2.35.1.1320.gc452695387.dirty


2024-06-13 15:02:39

by Sean Anderson

[permalink] [raw]
Subject: Re: [PATCH v2 4/4] phy: zynqmp: Add debugfs support

On 6/13/24 05:20, Pandey, Radhey Shyam wrote:
>> -----Original Message-----
>> From: Sean Anderson <[email protected]>
>> Sent: Monday, May 6, 2024 10:31 PM
>> To: Laurent Pinchart <[email protected]>; linux-
>> [email protected]
>> Cc: Vinod Koul <[email protected]>; [email protected];
>> [email protected]; Michal Simek <[email protected]>;
>> Kishon Vijay Abraham I <[email protected]>; Sean Anderson
>> <[email protected]>
>> Subject: [PATCH v2 4/4] phy: zynqmp: Add debugfs support
>>
>> Add support for printing some basic status information to debugfs. This
>> is helpful when debugging phy consumers to make sure they are configuring
>> the phy appropriately.
>>
>> Signed-off-by: Sean Anderson <[email protected]>
>> ---
>>
>> Changes in v2:
>> - Use debugfs_create_devm_seqfile
>>
>> drivers/phy/xilinx/phy-zynqmp.c | 40
>> +++++++++++++++++++++++++++++++++
>> 1 file changed, 40 insertions(+)
>>
>> diff --git a/drivers/phy/xilinx/phy-zynqmp.c b/drivers/phy/xilinx/phy-
>> zynqmp.c
>> index b86fe2a249a8..2520c75a4a77 100644
>> --- a/drivers/phy/xilinx/phy-zynqmp.c
>> +++ b/drivers/phy/xilinx/phy-zynqmp.c
>> @@ -13,6 +13,7 @@
>> */
>>
>> #include <linux/clk.h>
>> +#include <linux/debugfs.h>
>> #include <linux/delay.h>
>> #include <linux/io.h>
>> #include <linux/kernel.h>
>> @@ -123,6 +124,15 @@
>> #define ICM_PROTOCOL_DP 0x4
>> #define ICM_PROTOCOL_SGMII 0x5
>>
>> +static const char *const xpsgtr_icm_str[] = {
>> + [ICM_PROTOCOL_PD] = "powered down",
>
> Protocol saying powered down seems confusing.
> Should we say None or None(power down)?

Either works I guess. I'm just matching the define.

>> + [ICM_PROTOCOL_PCIE] = "PCIe",
>> + [ICM_PROTOCOL_SATA] = "SATA",
>> + [ICM_PROTOCOL_USB] = "USB",
>> + [ICM_PROTOCOL_DP] = "DisplayPort",
>> + [ICM_PROTOCOL_SGMII] = "SGMII",
>> +};
>> +
>> /* Test Mode common reset control parameters */
>> #define TM_CMN_RST 0x10018
>> #define TM_CMN_RST_EN 0x1
>> @@ -788,6 +798,34 @@ static struct phy *xpsgtr_xlate(struct device *dev,
>> return ERR_PTR(-EINVAL);
>> }
>>
>> +/*
>> + * DebugFS
>> + */
>> +
>> +static int xpsgtr_status_read(struct seq_file *seq, void *data)
>> +{
>> + struct device *dev = seq->private;
>> + struct xpsgtr_phy *gtr_phy = dev_get_drvdata(dev);
>> + struct clk *clk;
>> + u32 pll_status;
>> +
>> + mutex_lock(&gtr_phy->phy->mutex);
>
> Do we see any need for this lock? This function simply read hw register
> /phy members and decodes it.

It's to protect against modifications to gtr_phy->refclk and ->instance.

These are accessed under lock elsewhere; this is not a fast path and I don't
want to have to reason about the semantics when using a mutex is definitely
correct.

--Sean

>> + pll_status = xpsgtr_read_phy(gtr_phy, L0_PLL_STATUS_READ_1);
>> + clk = gtr_phy->dev->clk[gtr_phy->refclk];
>> +
>> + seq_printf(seq, "Lane: %u\n", gtr_phy->lane);
>> + seq_printf(seq, "Protocol: %s\n",
>> + xpsgtr_icm_str[gtr_phy->protocol]);
>> + seq_printf(seq, "Instance: %u\n", gtr_phy->instance);
>> + seq_printf(seq, "Reference clock: %u (%pC)\n", gtr_phy->refclk, clk);
>> + seq_printf(seq, "Reference rate: %lu\n", clk_get_rate(clk));
>> + seq_printf(seq, "PLL locked: %s\n",
>> + pll_status & PLL_STATUS_LOCKED ? "yes" : "no");
>> +
>> + mutex_unlock(&gtr_phy->phy->mutex);
>> + return 0;
>> +}
>> +
>> /*
>> * Power Management
>> */
>> @@ -937,6 +975,8 @@ static int xpsgtr_probe(struct platform_device *pdev)
>>
>> gtr_phy->phy = phy;
>> phy_set_drvdata(phy, gtr_phy);
>> + debugfs_create_devm_seqfile(&phy->dev, "status", phy-
>> >debugfs,
>> + xpsgtr_status_read);
>> }
>>
>> /* Register the PHY provider. */
>> --
>> 2.35.1.1320.gc452695387.dirty
>


2024-06-14 05:16:56

by Pandey, Radhey Shyam

[permalink] [raw]
Subject: RE: [PATCH v2 4/4] phy: zynqmp: Add debugfs support

> -----Original Message-----
> From: Sean Anderson <[email protected]>
> Sent: Thursday, June 13, 2024 8:32 PM
> To: Pandey, Radhey Shyam <[email protected]>; Laurent
> Pinchart <[email protected]>; linux-
> [email protected]
> Cc: Vinod Koul <[email protected]>; [email protected];
> [email protected]; Simek, Michal <[email protected]>;
> Kishon Vijay Abraham I <[email protected]>
> Subject: Re: [PATCH v2 4/4] phy: zynqmp: Add debugfs support
>
> On 6/13/24 05:20, Pandey, Radhey Shyam wrote:
> >> -----Original Message-----
> >> From: Sean Anderson <[email protected]>
> >> Sent: Monday, May 6, 2024 10:31 PM
> >> To: Laurent Pinchart <[email protected]>; linux-
> >> [email protected]
> >> Cc: Vinod Koul <[email protected]>; [email protected];
> >> [email protected]; Michal Simek <[email protected]>;
> >> Kishon Vijay Abraham I <[email protected]>; Sean Anderson
> >> <[email protected]>
> >> Subject: [PATCH v2 4/4] phy: zynqmp: Add debugfs support
> >>
> >> Add support for printing some basic status information to debugfs. This
> >> is helpful when debugging phy consumers to make sure they are
> configuring
> >> the phy appropriately.
> >>
> >> Signed-off-by: Sean Anderson <[email protected]>
> >> ---
> >>
> >> Changes in v2:
> >> - Use debugfs_create_devm_seqfile
> >>
> >> drivers/phy/xilinx/phy-zynqmp.c | 40
> >> +++++++++++++++++++++++++++++++++
> >> 1 file changed, 40 insertions(+)
> >>
> >> diff --git a/drivers/phy/xilinx/phy-zynqmp.c b/drivers/phy/xilinx/phy-
> >> zynqmp.c
> >> index b86fe2a249a8..2520c75a4a77 100644
> >> --- a/drivers/phy/xilinx/phy-zynqmp.c
> >> +++ b/drivers/phy/xilinx/phy-zynqmp.c
> >> @@ -13,6 +13,7 @@
> >> */
> >>
> >> #include <linux/clk.h>
> >> +#include <linux/debugfs.h>
> >> #include <linux/delay.h>
> >> #include <linux/io.h>
> >> #include <linux/kernel.h>
> >> @@ -123,6 +124,15 @@
> >> #define ICM_PROTOCOL_DP 0x4
> >> #define ICM_PROTOCOL_SGMII 0x5
> >>
> >> +static const char *const xpsgtr_icm_str[] = {
> >> + [ICM_PROTOCOL_PD] = "powered down",
> >
> > Protocol saying powered down seems confusing.
> > Should we say None or None(power down)?
>
> Either works I guess. I'm just matching the define.

None seems fine - we can respin if there are no objections.
>
> >> + [ICM_PROTOCOL_PCIE] = "PCIe",
> >> + [ICM_PROTOCOL_SATA] = "SATA",
> >> + [ICM_PROTOCOL_USB] = "USB",
> >> + [ICM_PROTOCOL_DP] = "DisplayPort",
> >> + [ICM_PROTOCOL_SGMII] = "SGMII",
> >> +};
> >> +
> >> /* Test Mode common reset control parameters */
> >> #define TM_CMN_RST 0x10018
> >> #define TM_CMN_RST_EN 0x1
> >> @@ -788,6 +798,34 @@ static struct phy *xpsgtr_xlate(struct device *dev,
> >> return ERR_PTR(-EINVAL);
> >> }
> >>
> >> +/*
> >> + * DebugFS
> >> + */
> >> +
> >> +static int xpsgtr_status_read(struct seq_file *seq, void *data)
> >> +{
> >> + struct device *dev = seq->private;
> >> + struct xpsgtr_phy *gtr_phy = dev_get_drvdata(dev);
> >> + struct clk *clk;
> >> + u32 pll_status;
> >> +
> >> + mutex_lock(&gtr_phy->phy->mutex);
> >
> > Do we see any need for this lock? This function simply read hw register
> > /phy members and decodes it.
>
> It's to protect against modifications to gtr_phy->refclk and ->instance.

Refclock and instance is assigned in xlate which is not protected by any
Lock. Also xpsgtr_phy_init () uses a different gtr_mutex. So want
to understand this phy->mutex need.

>
> These are accessed under lock elsewhere; this is not a fast path and I don't
> want to have to reason about the semantics when using a mutex is definitely
> correct.
>
> --Sean
>
> >> + pll_status = xpsgtr_read_phy(gtr_phy, L0_PLL_STATUS_READ_1);
> >> + clk = gtr_phy->dev->clk[gtr_phy->refclk];
> >> +
> >> + seq_printf(seq, "Lane: %u\n", gtr_phy->lane);
> >> + seq_printf(seq, "Protocol: %s\n",
> >> + xpsgtr_icm_str[gtr_phy->protocol]);
> >> + seq_printf(seq, "Instance: %u\n", gtr_phy->instance);
> >> + seq_printf(seq, "Reference clock: %u (%pC)\n", gtr_phy->refclk, clk);
> >> + seq_printf(seq, "Reference rate: %lu\n", clk_get_rate(clk));
> >> + seq_printf(seq, "PLL locked: %s\n",
> >> + pll_status & PLL_STATUS_LOCKED ? "yes" : "no");
> >> +
> >> + mutex_unlock(&gtr_phy->phy->mutex);
> >> + return 0;
> >> +}
> >> +
> >> /*
> >> * Power Management
> >> */
> >> @@ -937,6 +975,8 @@ static int xpsgtr_probe(struct platform_device
> *pdev)
> >>
> >> gtr_phy->phy = phy;
> >> phy_set_drvdata(phy, gtr_phy);
> >> + debugfs_create_devm_seqfile(&phy->dev, "status", phy-
> >> >debugfs,
> >> + xpsgtr_status_read);
> >> }
> >>
> >> /* Register the PHY provider. */
> >> --
> >> 2.35.1.1320.gc452695387.dirty
> >

2024-06-14 16:02:56

by Sean Anderson

[permalink] [raw]
Subject: Re: [PATCH v2 4/4] phy: zynqmp: Add debugfs support

On 6/14/24 01:16, Pandey, Radhey Shyam wrote:
>> -----Original Message-----
>> From: Sean Anderson <[email protected]>
>> Sent: Thursday, June 13, 2024 8:32 PM
>> To: Pandey, Radhey Shyam <[email protected]>; Laurent
>> Pinchart <[email protected]>; linux-
>> [email protected]
>> Cc: Vinod Koul <[email protected]>; [email protected];
>> [email protected]; Simek, Michal <[email protected]>;
>> Kishon Vijay Abraham I <[email protected]>
>> Subject: Re: [PATCH v2 4/4] phy: zynqmp: Add debugfs support
>>
>> On 6/13/24 05:20, Pandey, Radhey Shyam wrote:
>> >> -----Original Message-----
>> >> From: Sean Anderson <[email protected]>
>> >> Sent: Monday, May 6, 2024 10:31 PM
>> >> To: Laurent Pinchart <[email protected]>; linux-
>> >> [email protected]
>> >> Cc: Vinod Koul <[email protected]>; [email protected];
>> >> [email protected]; Michal Simek <[email protected]>;
>> >> Kishon Vijay Abraham I <[email protected]>; Sean Anderson
>> >> <[email protected]>
>> >> Subject: [PATCH v2 4/4] phy: zynqmp: Add debugfs support
>> >>
>> >> Add support for printing some basic status information to debugfs. This
>> >> is helpful when debugging phy consumers to make sure they are
>> configuring
>> >> the phy appropriately.
>> >>
>> >> Signed-off-by: Sean Anderson <[email protected]>
>> >> ---
>> >>
>> >> Changes in v2:
>> >> - Use debugfs_create_devm_seqfile
>> >>
>> >> drivers/phy/xilinx/phy-zynqmp.c | 40
>> >> +++++++++++++++++++++++++++++++++
>> >> 1 file changed, 40 insertions(+)
>> >>
>> >> diff --git a/drivers/phy/xilinx/phy-zynqmp.c b/drivers/phy/xilinx/phy-
>> >> zynqmp.c
>> >> index b86fe2a249a8..2520c75a4a77 100644
>> >> --- a/drivers/phy/xilinx/phy-zynqmp.c
>> >> +++ b/drivers/phy/xilinx/phy-zynqmp.c
>> >> @@ -13,6 +13,7 @@
>> >> */
>> >>
>> >> #include <linux/clk.h>
>> >> +#include <linux/debugfs.h>
>> >> #include <linux/delay.h>
>> >> #include <linux/io.h>
>> >> #include <linux/kernel.h>
>> >> @@ -123,6 +124,15 @@
>> >> #define ICM_PROTOCOL_DP 0x4
>> >> #define ICM_PROTOCOL_SGMII 0x5
>> >>
>> >> +static const char *const xpsgtr_icm_str[] = {
>> >> + [ICM_PROTOCOL_PD] = "powered down",
>> >
>> > Protocol saying powered down seems confusing.
>> > Should we say None or None(power down)?
>>
>> Either works I guess. I'm just matching the define.
>
> None seems fine - we can respin if there are no objections.
>>
>> >> + [ICM_PROTOCOL_PCIE] = "PCIe",
>> >> + [ICM_PROTOCOL_SATA] = "SATA",
>> >> + [ICM_PROTOCOL_USB] = "USB",
>> >> + [ICM_PROTOCOL_DP] = "DisplayPort",
>> >> + [ICM_PROTOCOL_SGMII] = "SGMII",
>> >> +};
>> >> +
>> >> /* Test Mode common reset control parameters */
>> >> #define TM_CMN_RST 0x10018
>> >> #define TM_CMN_RST_EN 0x1
>> >> @@ -788,6 +798,34 @@ static struct phy *xpsgtr_xlate(struct device *dev,
>> >> return ERR_PTR(-EINVAL);
>> >> }
>> >>
>> >> +/*
>> >> + * DebugFS
>> >> + */
>> >> +
>> >> +static int xpsgtr_status_read(struct seq_file *seq, void *data)
>> >> +{
>> >> + struct device *dev = seq->private;
>> >> + struct xpsgtr_phy *gtr_phy = dev_get_drvdata(dev);
>> >> + struct clk *clk;
>> >> + u32 pll_status;
>> >> +
>> >> + mutex_lock(&gtr_phy->phy->mutex);
>> >
>> > Do we see any need for this lock? This function simply read hw register
>> > /phy members and decodes it.
>>
>> It's to protect against modifications to gtr_phy->refclk and ->instance.
>
> Refclock and instance is assigned in xlate which is not protected by any
> Lock. Also xpsgtr_phy_init () uses a different gtr_mutex. So want
> to understand this phy->mutex need.

Ah, well then we should take this lock in xlate.

--Sean

>>
>> These are accessed under lock elsewhere; this is not a fast path and I don't
>> want to have to reason about the semantics when using a mutex is definitely
>> correct.
>>
>> --Sean
>>
>> >> + pll_status = xpsgtr_read_phy(gtr_phy, L0_PLL_STATUS_READ_1);
>> >> + clk = gtr_phy->dev->clk[gtr_phy->refclk];
>> >> +
>> >> + seq_printf(seq, "Lane: %u\n", gtr_phy->lane);
>> >> + seq_printf(seq, "Protocol: %s\n",
>> >> + xpsgtr_icm_str[gtr_phy->protocol]);
>> >> + seq_printf(seq, "Instance: %u\n", gtr_phy->instance);
>> >> + seq_printf(seq, "Reference clock: %u (%pC)\n", gtr_phy->refclk, clk);
>> >> + seq_printf(seq, "Reference rate: %lu\n", clk_get_rate(clk));
>> >> + seq_printf(seq, "PLL locked: %s\n",
>> >> + pll_status & PLL_STATUS_LOCKED ? "yes" : "no");
>> >> +
>> >> + mutex_unlock(&gtr_phy->phy->mutex);
>> >> + return 0;
>> >> +}
>> >> +
>> >> /*
>> >> * Power Management
>> >> */
>> >> @@ -937,6 +975,8 @@ static int xpsgtr_probe(struct platform_device
>> *pdev)
>> >>
>> >> gtr_phy->phy = phy;
>> >> phy_set_drvdata(phy, gtr_phy);
>> >> + debugfs_create_devm_seqfile(&phy->dev, "status", phy-
>> >> >debugfs,
>> >> + xpsgtr_status_read);
>> >> }
>> >>
>> >> /* Register the PHY provider. */
>> >> --
>> >> 2.35.1.1320.gc452695387.dirty
>> >
>