From f91a595d0b813c3a2f3b848c165e865ca4c5b8cc Mon Sep 17 00:00:00 2001 From: Nishanth Menon Date: Sat, 16 Mar 2013 11:46:44 +0530 Subject: memory: emif: Handle devices which are not rated for >85C As per JESD209-2E specification for LPDDR2, http://www.jedec.org/standards-documents/results/jesd209-2E Table 73, LPDDR2 memories come in two flavors - Standard and Extended. The Standard types can operate from -25C to +85C However, beyond that and upto +105C can only be supported by Extended types. Unfortunately, it seems there is no info in MR0(device info) or MR[1,2](device feature) for run time detection of this capability as far as seen on the spec. Hence, we provide a custom_config flag to be populated by platforms which have these "extended" type memories. For the "Standard" memories, we need to consider MR4 notifications of temperature triggers >85C as equivalent to thermal shutdown events (equivalent to Spec specified thermal shutdown events for "extended" parts). Reported-by: Richard Woodruff Signed-off-by: Nishanth Menon Signed-off-by: Lokesh Vutla Acked-by: Santosh Shilimkar Signed-off-by: Greg Kroah-Hartman --- drivers/memory/emif.c | 27 +++++++++++++++++++++++++++ include/linux/platform_data/emif_plat.h | 1 + 2 files changed, 28 insertions(+) diff --git a/drivers/memory/emif.c b/drivers/memory/emif.c index 249222905c9..96add5b9ce5 100644 --- a/drivers/memory/emif.c +++ b/drivers/memory/emif.c @@ -918,6 +918,7 @@ static irqreturn_t handle_temp_alert(void __iomem *base, struct emif_data *emif) { u32 old_temp_level; irqreturn_t ret = IRQ_HANDLED; + struct emif_custom_configs *custom_configs; spin_lock_irqsave(&emif_lock, irq_state); old_temp_level = emif->temperature_level; @@ -930,6 +931,29 @@ static irqreturn_t handle_temp_alert(void __iomem *base, struct emif_data *emif) goto out; } + custom_configs = emif->plat_data->custom_configs; + + /* + * IF we detect higher than "nominal rating" from DDR sensor + * on an unsupported DDR part, shutdown system + */ + if (custom_configs && !(custom_configs->mask & + EMIF_CUSTOM_CONFIG_EXTENDED_TEMP_PART)) { + if (emif->temperature_level >= SDRAM_TEMP_HIGH_DERATE_REFRESH) { + dev_err(emif->dev, + "%s:NOT Extended temperature capable memory." + "Converting MR4=0x%02x as shutdown event\n", + __func__, emif->temperature_level); + /* + * Temperature far too high - do kernel_power_off() + * from thread context + */ + emif->temperature_level = SDRAM_TEMP_VERY_HIGH_SHUTDOWN; + ret = IRQ_WAKE_THREAD; + goto out; + } + } + if (emif->temperature_level < old_temp_level || emif->temperature_level == SDRAM_TEMP_VERY_HIGH_SHUTDOWN) { /* @@ -1228,6 +1252,9 @@ static void __init_or_module of_get_custom_configs(struct device_node *np_emif, cust_cfgs->temp_alert_poll_interval_ms = *poll_intvl; } + if (of_find_property(np_emif, "extended-temp-part", &len)) + cust_cfgs->mask |= EMIF_CUSTOM_CONFIG_EXTENDED_TEMP_PART; + if (!is_custom_config_valid(cust_cfgs, emif->dev)) { devm_kfree(emif->dev, cust_cfgs); return; diff --git a/include/linux/platform_data/emif_plat.h b/include/linux/platform_data/emif_plat.h index 03378ca8406..5c19a2a647c 100644 --- a/include/linux/platform_data/emif_plat.h +++ b/include/linux/platform_data/emif_plat.h @@ -40,6 +40,7 @@ /* Custom config requests */ #define EMIF_CUSTOM_CONFIG_LPMODE 0x00000001 #define EMIF_CUSTOM_CONFIG_TEMP_ALERT_POLL_INTERVAL 0x00000002 +#define EMIF_CUSTOM_CONFIG_EXTENDED_TEMP_PART 0x00000004 #ifndef __ASSEMBLY__ /** -- cgit v1.2.3-18-g5258