From 3059c2f5a813ea2af0761705abc18848cd4e3c85 Mon Sep 17 00:00:00 2001 From: Joel Stanley Date: Mon, 1 Jul 2019 17:26:18 +0100 Subject: [PATCH] aspeed: Link SCU to the watchdog MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The ast2500 uses the watchdog to reset the SDRAM controller. This operation is usually performed by u-boot's memory training procedure, and it is enabled by setting a bit in the SCU and then causing the watchdog to expire. Therefore, we need the watchdog to be able to access the SCU's register space. This causes the watchdog to not perform a system reset when the bit is set. In the future it could perform a reset of the SDMC model. Signed-off-by: Joel Stanley Signed-off-by: Cédric Le Goater Reviewed-by: Cédric Le Goater Reviewed-by: Philippe Mathieu-Daudé Message-id: 20190621065242.32535-1-joel@jms.id.au Signed-off-by: Peter Maydell --- hw/arm/aspeed_soc.c | 2 ++ hw/watchdog/wdt_aspeed.c | 20 ++++++++++++++++++++ include/hw/watchdog/wdt_aspeed.h | 1 + 3 files changed, 23 insertions(+) diff --git a/hw/arm/aspeed_soc.c b/hw/arm/aspeed_soc.c index 443e4c49f2..c6fb3700f2 100644 --- a/hw/arm/aspeed_soc.c +++ b/hw/arm/aspeed_soc.c @@ -235,6 +235,8 @@ static void aspeed_soc_init(Object *obj) sizeof(s->wdt[i]), TYPE_ASPEED_WDT); qdev_prop_set_uint32(DEVICE(&s->wdt[i]), "silicon-rev", sc->info->silicon_rev); + object_property_add_const_link(OBJECT(&s->wdt[i]), "scu", + OBJECT(&s->scu), &error_abort); } for (i = 0; i < ASPEED_MACS_NUM; i++) { diff --git a/hw/watchdog/wdt_aspeed.c b/hw/watchdog/wdt_aspeed.c index 4a8409f0da..57fe24ae6b 100644 --- a/hw/watchdog/wdt_aspeed.c +++ b/hw/watchdog/wdt_aspeed.c @@ -44,6 +44,9 @@ #define WDT_RESTART_MAGIC 0x4755 +#define SCU_RESET_CONTROL1 (0x04 / 4) +#define SCU_RESET_SDRAM BIT(0) + static bool aspeed_wdt_is_enabled(const AspeedWDTState *s) { return s->regs[WDT_CTRL] & WDT_CTRL_ENABLE; @@ -222,6 +225,13 @@ static void aspeed_wdt_timer_expired(void *dev) { AspeedWDTState *s = ASPEED_WDT(dev); + /* Do not reset on SDRAM controller reset */ + if (s->scu->regs[SCU_RESET_CONTROL1] & SCU_RESET_SDRAM) { + timer_del(s->timer); + s->regs[WDT_CTRL] = 0; + return; + } + qemu_log_mask(CPU_LOG_RESET, "Watchdog timer expired.\n"); watchdog_perform_action(); timer_del(s->timer); @@ -233,6 +243,16 @@ static void aspeed_wdt_realize(DeviceState *dev, Error **errp) { SysBusDevice *sbd = SYS_BUS_DEVICE(dev); AspeedWDTState *s = ASPEED_WDT(dev); + Error *err = NULL; + Object *obj; + + obj = object_property_get_link(OBJECT(dev), "scu", &err); + if (!obj) { + error_propagate(errp, err); + error_prepend(errp, "required link 'scu' not found: "); + return; + } + s->scu = ASPEED_SCU(obj); if (!is_supported_silicon_rev(s->silicon_rev)) { error_setg(errp, "Unknown silicon revision: 0x%" PRIx32, diff --git a/include/hw/watchdog/wdt_aspeed.h b/include/hw/watchdog/wdt_aspeed.h index 88d8be4f78..daef0c0e23 100644 --- a/include/hw/watchdog/wdt_aspeed.h +++ b/include/hw/watchdog/wdt_aspeed.h @@ -27,6 +27,7 @@ typedef struct AspeedWDTState { MemoryRegion iomem; uint32_t regs[ASPEED_WDT_REGS_MAX]; + AspeedSCUState *scu; uint32_t pclk_freq; uint32_t silicon_rev; uint32_t ext_pulse_width_mask;