-----Original Message-----
From: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Sent: Wednesday, March 22, 2023 11:07 PM
To: Zhang, Tianfei <redacted>
Cc: richardcochran@gmail.com; Netdev <redacted>; linux-
fpga@vger.kernel.org; Andy Shevchenko [off-list ref];
Gomes, Vinicius [off-list ref]; pierre-louis.bossart@linux.intel.com;
Pagani, Marco [off-list ref]; Weight, Russell H
[off-list ref]; matthew.gerlach@linux.intel.com; nico@fluxnic.net;
Khadatare, RaghavendraX Anand [off-list ref]
Subject: Re: [PATCH v2] ptp: add ToD device driver for Intel FPGA cards

On Wed, 22 Mar 2023, Tianfei Zhang wrote:

quoted

Adding a DFL (Device Feature List) device driver of ToD device for
Intel FPGA cards.

The Intel FPGA Time of Day(ToD) IP within the FPGA DFL bus is exposed
as PTP Hardware clock(PHC) device to the Linux PTP stack to
synchronize the system clock to its ToD information using phc2sys
utility of the Linux PTP stack. The DFL is a hardware List within
FPGA, which defines a linked list of feature headers within the device
MMIO space to provide an extensible way of adding subdevice features.

Signed-off-by: Raghavendra Khadatare
[off-list ref]
Signed-off-by: Tianfei Zhang <redacted>

---
v2:
- handle NULL for ptp_clock_register().
- use readl_poll_timeout_atomic() instead of readl_poll_timeout(), and
  change the interval timeout to 10us.
- fix the uninitialized variable.
---
 MAINTAINERS               |   7 +
 drivers/ptp/Kconfig       |  13 ++
 drivers/ptp/Makefile      |   1 +
 drivers/ptp/ptp_dfl_tod.c | 333
++++++++++++++++++++++++++++++++++++++
 4 files changed, 354 insertions(+)
 create mode 100644 drivers/ptp/ptp_dfl_tod.c

diff --git a/MAINTAINERS b/MAINTAINERS index

d8ebab595b2a..3fd603369464 100644

--- a/MAINTAINERS
+++ b/MAINTAINERS

@@ -15623,6 +15623,13 @@ L:	netdev@vger.kernel.org
 S:	Maintained
 F:	drivers/ptp/ptp_ocp.c

+INTEL PTP DFL ToD DRIVER
+M:	Tianfei Zhang <tianfei.zhang@intel.com>
+L:	linux-fpga@vger.kernel.org
+L:	netdev@vger.kernel.org
+S:	Maintained
+F:	drivers/ptp/ptp_dfl_tod.c
+
 OPENCORES I2C BUS DRIVER
 M:	Peter Korsgaard <peter@korsgaard.com>
 M:	Andrew Lunn <andrew@lunn.ch>

diff --git a/drivers/ptp/Kconfig b/drivers/ptp/Kconfig index

fe4971b65c64..e0d6f136ee46 100644

--- a/drivers/ptp/Kconfig
+++ b/drivers/ptp/Kconfig

@@ -186,4 +186,17 @@ config PTP_1588_CLOCK_OCP

 	  More information is available at http://www.timingcard.com/

+config PTP_DFL_TOD
+	tristate "FPGA DFL ToD Driver"
+	depends on FPGA_DFL

Should this also have depends on PTP_1588_CLOCK?

Yes, I will add it later.