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.
> 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.
> + /* 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
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