From: Nishanth Menon n...@ti.com
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-woodru...@ti.com
Signed-off-by: Nishanth Menon n...@ti.com
Signed-off-by: Lokesh Vutla lokeshvu...@ti.com
---
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 37e0c77..927fb55 100644
--- a/drivers/memory/emif.c
+++ b/drivers/memory/emif.c
@@ -914,6 +914,7 @@ 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;
@@ -926,6 +927,29 @@ 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) {
/*
@@ -1224,6 +1248,9 @@ 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 03378ca..5c19a2a 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 0x0001
#define EMIF_CUSTOM_CONFIG_TEMP_ALERT_POLL_INTERVAL0x0002
+#define EMIF_CUSTOM_CONFIG_EXTENDED_TEMP_PART 0x0004
#ifndef __ASSEMBLY__
/**
--
1.7.9.5
--
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