[v1,0/3] Add WDT driver for RZ/G2L

Message

Biju Das Nov. 11, 2021, 8:52 a.m. UTC

This patch series aims to add WDT driver support for RZ/G2L SoC's.

WDT has 3 channels 
1) CH0 to check the operation of Cortex-A55-CPU Core0
2) CH1 to check the operation of Cortex-A55-CPU Core1
3) CH2 to check the operation of Cortex-M33 CPU

WDT IP supports 
1) Normal Watchdog Timer Function
2) Reset Request Function due to CPU Parity Error

Once the software activates the watchdog timer, the watchdog timer does
not stop until it is reset.

The WDT Overflow System Reset Register (CPG_WDTOVF_RST) and 
WDT Reset Selector Register (CPG_WDTRST_SEL) are in CPG IP
block.

Current driver supports Normal Watchdog Timer basic functionality.

Tested WDT driver with selftests tool and reboot command

All 3 channels tested with below command.

cat /dev/watchdog  & for i in {1..60}; do sleep 1; echo $i; devmem2 0x12800808; done
cat /dev/watchdog1  & for i in {1..60}; do sleep 1; echo $i; devmem2 0x12800c08; done
cat /dev/watchdog2 & for i in {1..60}; do sleep 1; echo $i; devmem2 0x12800408; done


RFC->V1
 * Removed patch#3, the clk patch is queued for 5.17
 * Added clock-names and interrupt-names as required properties for RZ/G2L
 * Re-order clocknames with internal module clock first
 * Removed pclk_rate from priv.
 * rzg2l_wdt_write() returns void and Removed tiemout related to register update 
 * rzg2l_wdt_init_timeout() returns void and removed delays.
 * removed set_bit(WDOG_HW_RUNNING,..) as we can stop watchdog
 * renamed reset_assert_clock_disable->reset_assert_pm_disable_put
 * started using devm_reset_control_get_exclusive()
 * removed platform_set_drvdata(pdev, priv) as there is no user
 * removed watchdog_set_restart_priority(&priv->wdev, 0) as 0 is the default.
 * removed remove callback as it is empty.

Biju Das (3):
  clk: renesas: rzg2l: Add support for watchdog reset selection
  dt-bindings: watchdog: renesas,wdt: Add support for RZ/G2L
  watchdog: Add Watchdog Timer driver for RZ/G2L

 .../bindings/watchdog/renesas,wdt.yaml        |  75 +++--
 drivers/clk/renesas/r9a07g044-cpg.c           |  22 ++
 drivers/clk/renesas/rzg2l-cpg.c               |   6 +
 drivers/clk/renesas/rzg2l-cpg.h               |  14 +
 drivers/watchdog/Kconfig                      |   8 +
 drivers/watchdog/Makefile                     |   1 +
 drivers/watchdog/rzg2l_wdt.c                  | 262 ++++++++++++++++++
 7 files changed, 370 insertions(+), 18 deletions(-)
 create mode 100644 drivers/watchdog/rzg2l_wdt.c