[PATCH v2 net-next 1/3] ptp: ptp_clockmatrix: Add wait_for_sys_apll_dpll_lock.

From: vincent.cheng.xh
Date: Sat Feb 13 2021 - 00:38:12 EST


From: Vincent Cheng <vincent.cheng.xh@xxxxxxxxxxx>

Part of the device initialization aligns the rising edge of the output
clock to the internal 1 PPS clock. If the system APLL and DPLL is not
locked, then the alignment will fail and there will be a fixed offset
between the internal 1 PPS clock and the output clock.

After loading the device firmware, poll the system APLL and DPLL for
locked state prior to initialization, timing out after 2 seconds.

Signed-off-by: Vincent Cheng <vincent.cheng.xh@xxxxxxxxxxx>
Acked-by: Richard Cochran <richardcochran@xxxxxxxxx>
---
drivers/ptp/idt8a340_reg.h | 10 ++++++
drivers/ptp/ptp_clockmatrix.c | 76 +++++++++++++++++++++++++++++++++++++++++--
drivers/ptp/ptp_clockmatrix.h | 15 +++++++++
3 files changed, 99 insertions(+), 2 deletions(-)

diff --git a/drivers/ptp/idt8a340_reg.h b/drivers/ptp/idt8a340_reg.h
index a664dfe..ac524cf 100644
--- a/drivers/ptp/idt8a340_reg.h
+++ b/drivers/ptp/idt8a340_reg.h
@@ -122,6 +122,8 @@
#define OTP_SCSR_CONFIG_SELECT 0x0022

#define STATUS 0xc03c
+#define DPLL_SYS_STATUS 0x0020
+#define DPLL_SYS_APLL_STATUS 0x0021
#define USER_GPIO0_TO_7_STATUS 0x008a
#define USER_GPIO8_TO_15_STATUS 0x008b

@@ -707,4 +709,12 @@
/* Bit definitions for the DPLL_CTRL_COMBO_MASTER_CFG register */
#define COMBO_MASTER_HOLD BIT(0)

+/* Bit definitions for DPLL_SYS_STATUS register */
+#define DPLL_SYS_STATE_MASK (0xf)
+
+/* Bit definitions for SYS_APLL_STATUS register */
+#define SYS_APLL_LOSS_LOCK_LIVE_MASK BIT(0)
+#define SYS_APLL_LOSS_LOCK_LIVE_LOCKED 0
+#define SYS_APLL_LOSS_LOCK_LIVE_UNLOCKED 1
+
#endif
diff --git a/drivers/ptp/ptp_clockmatrix.c b/drivers/ptp/ptp_clockmatrix.c
index 051511f..3de8411 100644
--- a/drivers/ptp/ptp_clockmatrix.c
+++ b/drivers/ptp/ptp_clockmatrix.c
@@ -335,6 +335,79 @@ static int wait_for_boot_status_ready(struct idtcm *idtcm)
return -EBUSY;
}

+static int read_sys_apll_status(struct idtcm *idtcm, u8 *status)
+{
+ int err;
+
+ err = idtcm_read(idtcm, STATUS, DPLL_SYS_APLL_STATUS, status,
+ sizeof(u8));
+
+ return err;
+}
+
+static int read_sys_dpll_status(struct idtcm *idtcm, u8 *status)
+{
+ int err;
+
+ err = idtcm_read(idtcm, STATUS, DPLL_SYS_STATUS, status, sizeof(u8));
+
+ return err;
+}
+
+static int wait_for_sys_apll_dpll_lock(struct idtcm *idtcm)
+{
+ const char *fmt = "%d ms SYS lock timeout: APLL Loss Lock %d DPLL state %d";
+ u8 i = LOCK_TIMEOUT_MS / LOCK_POLL_INTERVAL_MS;
+ u8 apll = 0;
+ u8 dpll = 0;
+
+ int err;
+
+ do {
+ err = read_sys_apll_status(idtcm, &apll);
+
+ if (err)
+ return err;
+
+ err = read_sys_dpll_status(idtcm, &dpll);
+
+ if (err)
+ return err;
+
+ apll &= SYS_APLL_LOSS_LOCK_LIVE_MASK;
+ dpll &= DPLL_SYS_STATE_MASK;
+
+ if ((apll == SYS_APLL_LOSS_LOCK_LIVE_LOCKED)
+ && (dpll == DPLL_STATE_LOCKED)) {
+ return 0;
+ } else if ((dpll == DPLL_STATE_FREERUN) ||
+ (dpll == DPLL_STATE_HOLDOVER) ||
+ (dpll == DPLL_STATE_OPEN_LOOP)) {
+ dev_warn(&idtcm->client->dev,
+ "No wait state: DPLL_SYS_STATE %d", dpll);
+ return -EPERM;
+ }
+
+ msleep(LOCK_POLL_INTERVAL_MS);
+ i--;
+
+ } while (i);
+
+ dev_warn(&idtcm->client->dev, fmt, LOCK_TIMEOUT_MS, apll, dpll);
+
+ return -ETIME;
+}
+
+static void wait_for_chip_ready(struct idtcm *idtcm)
+{
+ if (wait_for_boot_status_ready(idtcm))
+ dev_warn(&idtcm->client->dev, "BOOT_STATUS != 0xA0");
+
+ if (wait_for_sys_apll_dpll_lock(idtcm))
+ dev_warn(&idtcm->client->dev,
+ "Continuing while SYS APLL/DPLL is not locked");
+}
+
static int _idtcm_gettime(struct idtcm_channel *channel,
struct timespec64 *ts)
{
@@ -2235,8 +2308,7 @@ static int idtcm_probe(struct i2c_client *client,
dev_warn(&idtcm->client->dev,
"loading firmware failed with %d\n", err);

- if (wait_for_boot_status_ready(idtcm))
- dev_warn(&idtcm->client->dev, "BOOT_STATUS != 0xA0\n");
+ wait_for_chip_ready(idtcm);

if (idtcm->tod_mask) {
for (i = 0; i < MAX_TOD; i++) {
diff --git a/drivers/ptp/ptp_clockmatrix.h b/drivers/ptp/ptp_clockmatrix.h
index 645de2c..0233236 100644
--- a/drivers/ptp/ptp_clockmatrix.h
+++ b/drivers/ptp/ptp_clockmatrix.h
@@ -51,6 +51,9 @@
#define TOD_WRITE_OVERHEAD_COUNT_MAX (2)
#define TOD_BYTE_COUNT (11)

+#define LOCK_TIMEOUT_MS (2000)
+#define LOCK_POLL_INTERVAL_MS (10)
+
#define PEROUT_ENABLE_OUTPUT_MASK (0xdeadbeef)

#define IDTCM_MAX_WRITE_COUNT (512)
@@ -105,6 +108,18 @@ enum scsr_tod_write_type_sel {
SCSR_TOD_WR_TYPE_SEL_MAX = SCSR_TOD_WR_TYPE_SEL_DELTA_MINUS,
};

+/* Values STATUS.DPLL_SYS_STATUS.DPLL_SYS_STATE */
+enum dpll_state {
+ DPLL_STATE_MIN = 0,
+ DPLL_STATE_FREERUN = DPLL_STATE_MIN,
+ DPLL_STATE_LOCKACQ = 1,
+ DPLL_STATE_LOCKREC = 2,
+ DPLL_STATE_LOCKED = 3,
+ DPLL_STATE_HOLDOVER = 4,
+ DPLL_STATE_OPEN_LOOP = 5,
+ DPLL_STATE_MAX = DPLL_STATE_OPEN_LOOP,
+};
+
struct idtcm;

struct idtcm_channel {
--
2.7.4