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authorNishanth Menon <nm@ti.com>2013-03-16 11:46:44 +0530
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-03-25 13:18:12 -0700
commitf91a595d0b813c3a2f3b848c165e865ca4c5b8cc (patch)
treec14fc79d76636ef6118e0252c2408907c634d9a9 /drivers/memory/emif.c
parent25aaacd2834233bbfa2b7ec697bfce42707e35b7 (diff)
downloadlwn-f91a595d0b813c3a2f3b848c165e865ca4c5b8cc.tar.gz
lwn-f91a595d0b813c3a2f3b848c165e865ca4c5b8cc.zip
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 <r-woodruff2@ti.com> Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/memory/emif.c')
-rw-r--r--drivers/memory/emif.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/memory/emif.c b/drivers/memory/emif.c
index 249222905c94..96add5b9ce5d 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;