On Thursday 16 February 2012 04:11 PM, Santosh Shilimkar wrote:
On Saturday 04 February 2012 05:46 PM, Aneesh V wrote:
Add an ISR for EMIF that:
1. reports details of access errors
2. takes action on thermal events
On thermal events SDRAM timing parameters are
adjusted to ensure safe operation
Also clear all interrupts on shut-down. Pending IRQs
may casue problems during warm-reset.
Add some more details like MR4, EMIF polling frequency etc
for better understanding.
Will do.
Signed-off-by: Aneesh V<ane...@ti.com>
---
drivers/misc/emif.c | 209 ++++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 207 insertions(+), 2 deletions(-)
diff --git a/drivers/misc/emif.c b/drivers/misc/emif.c
index 36ba6f4..5c2b0ae 100644
--- a/drivers/misc/emif.c
+++ b/drivers/misc/emif.c
@@ -500,6 +500,45 @@ static u32 get_pwr_mgmt_ctrl(u32 freq, struct emif_data
*emif, u32 ip_rev)
}
/*
+ * Get the temperature level of the EMIF instance:
+ * Reads the MR4 register of attached SDRAM parts to find out the temperature
+ * level. If there are two parts attached(one on each CS), then the temperature
+ * level for the EMIF instance is the higher of the two temperatures.
+ */
+static void get_temperature_level(struct emif_data *emif)
+{
+ u32 temp, temperature_level;
+ unsigned long irqs;
+ void __iomem *base;
+
+ base = emif->base;
+
+ /* Read mode register 4 */
+ writel(DDR_MR4, base + EMIF_LPDDR2_MODE_REG_CONFIG);
+ temperature_level = readl(base + EMIF_LPDDR2_MODE_REG_DATA);
+ temperature_level = (temperature_level& MR4_SDRAM_REF_RATE_MASK)>>
+ MR4_SDRAM_REF_RATE_SHIFT;
+
+ if (emif->plat_data->device_info->cs1_used) {
+ writel(DDR_MR4 | CS_MASK, base + EMIF_LPDDR2_MODE_REG_CONFIG);
+ temp = readl(base + EMIF_LPDDR2_MODE_REG_DATA);
+ temp = (temp& MR4_SDRAM_REF_RATE_MASK)
+ >> MR4_SDRAM_REF_RATE_SHIFT;
+ temperature_level = max(temp, temperature_level);
+ }
+
+ spin_lock_irqsave(&emif->lock, irqs);
Add a line here.
Will do.
+ /* treat everything less than nominal(3) in MR4 as nominal */
+ if (unlikely(temperature_level< SDRAM_TEMP_NOMINAL))
+ temperature_level = SDRAM_TEMP_NOMINAL;
+
+ /* if we get reserved value in MR4 persist with the existing value */
+ if (likely(temperature_level != SDRAM_TEMP_RESERVED_4))
+ emif->temperature_level = temperature_level;
+ spin_unlock_irqrestore(&emif->lock, irqs);
+}
+
rest of the patch looks fine to me
Thanks,
Aneesh
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