2024-05-06 17:01:47

by Sean Anderson

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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

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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