drivers: qcom: RNG and WDT Driver Consolidation by thariaruchamy-bit · Pull Request #7855 · OP-TEE/optee_os

thariaruchamy-bit · 2026-06-24T11:46:50Z

This pull request consolidates and refactors QCOM RNG and WDT drivers
with unified naming conventions and improved configuration management.

RNG Driver Consolidation

Refactor PRNG driver into generic RNG implementation:

Rename prng.c to qcom-rng.c for platform-agnostic naming
Move driver source inclusion to parent qcom/sub.mk with CFG_QCOM_RNG flag
Simplify driver by using generic RNG naming conventions

Platform configuration updates:

Update from CFG_QCOM_PRNG to unified CFG_QCOM_RNG
Configure RNG_REG_BASE for PRNG variant
Enable CFG_HWRNG_PTA configuration for ipq52xx
When HWRNG_PTA is enabled:
- Disable CFG_WITH_SOFTWARE_PRNG to prevent fallback
- Force enable CFG_QCOM_RNG to use hardware RNG driver
- Configure HWRNG quality to 1024 bits entropy
- Set HWRNG rate to 0 (unlimited)

Secure Watchdog Driver

Add secure watchdog driver for Bobcat family:

QCOM platforms manage secure watchdog via driver_init() without framework
registration. This is sufficient as QCOM currently does not require HLOS
control over the secure watchdog. The implementation maintains separation
between secure and non-secure world watchdog management.

Implementation details:

Maps WDT_TMR_BASE into secure I/O memory
Configures bark timeout (6s) and bite timeout (22s) using 32 KHz clock
Registers qcom_sec_wdog_bark_handler() for WDT_BARK_INT_ID
Bark handler pets watchdog by writing to WDT_RESET_REG register

Platform enablement for Bobcat family:

CFG_QCOM_SEC_WDOG enabled in bobcat/arch.mk for all Bobcat targets
Per-target hardware addresses defined in target-specific configs:
- ipq96xx/ipq54xx: base=0x0F411000, bark_int=0x36
- ipq52xx: base=0x0B117000, bark_int=0x23

github-actions · 2026-06-24T12:12:07Z

FYI @ldts @b49020 @zelvam95

zelvam95 · 2026-06-25T09:53:32Z

Based on above + earlier elaborate review here qualcomm-linux/optee_os#15

Reviewed-by: Selvam Sathappan Periakaruppan <speriaka@qti.qualcomm.com>

thariaruchamy-bit · 2026-06-25T09:53:38Z

@b49020 @ldts Gentle remainder to share any other feedback.

- Rename prng.c to qcom-rng.c for platform-agnostic naming - Move driver source inclusion to parent qcom/sub.mk with CFG_QCOM_RNG flag - Simplify driver by using generic RNG naming conventions Change-Id: I5b262d5038e10aca7f6b4e8ee93847006b1b0a9f Signed-off-by: Harikrishna <hart@qti.qualcomm.com> Reviewed-by: Selvam Sathappan Periakaruppan <speriaka@qti.qualcomm.com>

- Update from CFG_QCOM_PRNG to unified CFG_QCOM_RNG - Configure RNG_REG_BASE for PRNG variant - Enable CFG_HWRNG_PTA configuration for ipq52xx - When HWRNG_PTA is enabled: - Disable CFG_WITH_SOFTWARE_PRNG to prevent fallback - Force enable CFG_QCOM_RNG to use hardware QRNG driver - Configure HWRNG quality to 1024 bits entropy - Set HWRNG rate to 0 (unlimited) Signed-off-by: Harikrishna <hart@qti.qualcomm.com> Reviewed-by: Selvam Sathappan Periakaruppan <speriaka@qti.qualcomm.com>

QCOM platforms manage secure watchdog via driver_init() without framework registration. This is sufficient as QCOM currently does not require HLOS control over the secure watchdog. The implementation maintains separation between secure and non-secure world watchdog management. Key implementation details: - Maps APSS_WDT_TMR2_BASE into secure I/O memory - Configures bark timeout (6s) and bite timeout (22s) using a 32 KHz watchdog clock, converting milliseconds to hardware ticks - Registers qcom_sec_wdog_bark_handler() for SEC_WDOG_BARK_INT_ID via interrupt_create_handler() - Bark handler pets the watchdog by writing to WDOG_RESET register Signed-off-by: Harikrishna <hart@qti.qualcomm.com> Reviewed-by: Selvam Sathappan Periakaruppan <speriaka@qti.qualcomm.com>

- CFG_QCOM_SEC_WDOG enabled in bobcat/arch.mk for all Bobcat targets - Per-target hardware addresses (WDT_TMR_BASE, WDT_BARK_INT_ID, WDT_RESET_REG_OFFSET) defined in target-specific target_config.h files: - ipq96xx/ipq54xx: base=0x0F411000, bark_int=0x36 - ipq52xx: base=0x0B117000, bark_int=0x23 Signed-off-by: Harikrishna <hart@qti.qualcomm.com> Reviewed-by: Selvam Sathappan Periakaruppan <speriaka@qti.qualcomm.com>

b49020 · 2026-06-26T11:32:43Z

 }

-static TEE_Result qcom_prng_init(void)
+static TEE_Result rng_init(void)


Rather rename the API as qcom_rng_init().

b49020 · 2026-06-26T11:35:43Z

+#
+
+global-incdirs-y += .
+srcs-$(CFG_QCOM_RNG) += qcom-rng.c


Is this sub.mk really needed as you include the file in outside sub.mk directly?

b49020 · 2026-06-26T11:36:42Z

 #include <rng_support.h>

-#define SEC_PRNG_REG_SIZE			0x1000
+#define RNG_REG_SIZE				0x1000


Rather rename all the macros with a QCOM_ prefix

b49020 · 2026-06-26T11:37:47Z

-} prng = {
-	.pa = SEC_PRNG_REG_BASE,
+} rng = {
+	.pa = RNG_REG_BASE,


This will break build after this individual commit, change the targets to define the new macro: QCOM_RNG_REG_BASE in this commit only.

b49020 · 2026-06-26T11:39:33Z

 CFG_QCOM_RAMBLUR_TA_WINDOW_ID ?= 2

-$(call force,CFG_QCOM_PRNG,y)
+$(call force,CFG_QCOM_RNG,y)


These changes should be folded in prior commit as the driver was already enabled for hoya platforms.

b49020 · 2026-06-26T11:41:19Z

Don't write commit descriptions as all the bullet point, rather than write small paras to summarize.

b49020 · 2026-06-26T11:44:26Z

+static uint32_t ms_to_ticks_wdt(uint32_t ms)
+{
+	return (uint32_t)(((uint64_t)ms * WDT_CLK_HZ) / 1000U);
+}


Rather create a macro for this

b49020 · 2026-06-26T11:45:26Z

+	return TEE_SUCCESS;
+}
+
+driver_init(wdt_init);


Use qcom_ prefixes for the APIs and macros.

b49020 · 2026-06-26T11:45:46Z


 srcs-$(CFG_QCOM_RAMBLUR_PIMEM_V3) += ramblur/ramblur_pimem_v3.c
 srcs-$(CFG_QCOM_RNG) += rng/qcom-rng.c
+srcs-$(CFG_QCOM_SEC_WDOG) += wdt/wdt.c


rename file as qcom-wdt.c

b49020 · 2026-06-26T11:46:47Z

 #define RNG_REG_BASE			UL(0x4C5000)

+#define WDT_TMR_BASE			UL(0x0B117000)
+#define WDT_RESET_REG_OFFSET		UL(0x4)


Can this offset macro move to the driver itself?

zelvam95 reviewed Jun 25, 2026

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Comment thread core/drivers/qcom/rng/qcom-rng.c Outdated

zelvam95 reviewed Jun 25, 2026

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Comment thread core/drivers/qcom/wdt/wdt.c Outdated

thariaruchamy-bit force-pushed the optee-upstream branch 2 times, most recently from 3dd88b6 to 24ab177 Compare June 25, 2026 07:11

zelvam95 reviewed Jun 26, 2026

View reviewed changes

Comment thread core/arch/arm/plat-qcom/bobcat/qcom-arch.mk

Harikrishna added 4 commits June 26, 2026 12:53

thariaruchamy-bit force-pushed the optee-upstream branch from 24ab177 to c9b45b6 Compare June 26, 2026 07:27

b49020 suggested changes Jun 26, 2026

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