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| author | Nishanth Menon <nm@ti.com> | 2013-03-16 11:46:44 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-25 13:18:12 -0700 |
| commit | f91a595d0b813c3a2f3b848c165e865ca4c5b8cc (patch) | |
| tree | c14fc79d76636ef6118e0252c2408907c634d9a9 /drivers/memory/emif.c | |
| parent | 25aaacd2834233bbfa2b7ec697bfce42707e35b7 (diff) | |
| download | linux-f91a595d0b813c3a2f3b848c165e865ca4c5b8cc.tar.bz2 | |
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.c | 27 |
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; |