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authorNishanth Menon <nm@ti.com>2013-03-16 10:16:43 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-03-26 00:18:12 +0400
commit25aaacd2834233bbfa2b7ec697bfce42707e35b7 (patch)
treeb8352a0f79151e2255c5c9736fbcdf604bf9895d /drivers/memory
parent9ea03dec380208bfee015b25f253c2f58aba0071 (diff)
downloadlinux-25aaacd2834233bbfa2b7ec697bfce42707e35b7.tar.xz
memory: emif: handle overflow for timing for LP mode
In case the custom timings provide values which overflow the maximum possible field value, warn and use maximum permissible value. 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')
-rw-r--r--drivers/memory/emif.c36
1 files changed, 28 insertions, 8 deletions
diff --git a/drivers/memory/emif.c b/drivers/memory/emif.c
index bda11ebb25cd..249222905c94 100644
--- a/drivers/memory/emif.c
+++ b/drivers/memory/emif.c
@@ -715,6 +715,8 @@ static u32 get_pwr_mgmt_ctrl(u32 freq, struct emif_data *emif, u32 ip_rev)
u32 timeout_perf = EMIF_LP_MODE_TIMEOUT_PERFORMANCE;
u32 timeout_pwr = EMIF_LP_MODE_TIMEOUT_POWER;
u32 freq_threshold = EMIF_LP_MODE_FREQ_THRESHOLD;
+ u32 mask;
+ u8 shift;
struct emif_custom_configs *cust_cfgs = emif->plat_data->custom_configs;
@@ -743,27 +745,45 @@ static u32 get_pwr_mgmt_ctrl(u32 freq, struct emif_data *emif, u32 ip_rev)
switch (lpmode) {
case EMIF_LP_MODE_CLOCK_STOP:
- pwr_mgmt_ctrl = (timeout << CS_TIM_SHIFT) |
- SR_TIM_MASK | PD_TIM_MASK;
+ shift = CS_TIM_SHIFT;
+ mask = CS_TIM_MASK;
break;
case EMIF_LP_MODE_SELF_REFRESH:
/* Workaround for errata i735 */
if (timeout < 6)
timeout = 6;
- pwr_mgmt_ctrl = (timeout << SR_TIM_SHIFT) |
- CS_TIM_MASK | PD_TIM_MASK;
+ shift = SR_TIM_SHIFT;
+ mask = SR_TIM_MASK;
break;
case EMIF_LP_MODE_PWR_DN:
- pwr_mgmt_ctrl = (timeout << PD_TIM_SHIFT) |
- CS_TIM_MASK | SR_TIM_MASK;
+ shift = PD_TIM_SHIFT;
+ mask = PD_TIM_MASK;
break;
case EMIF_LP_MODE_DISABLE:
default:
- pwr_mgmt_ctrl = CS_TIM_MASK |
- PD_TIM_MASK | SR_TIM_MASK;
+ mask = 0;
+ shift = 0;
+ break;
+ }
+ /* Round to maximum in case of overflow, BUT warn! */
+ if (lpmode != EMIF_LP_MODE_DISABLE && timeout > mask >> shift) {
+ pr_err("TIMEOUT Overflow - lpmode=%d perf=%d pwr=%d freq=%d\n",
+ lpmode,
+ timeout_perf,
+ timeout_pwr,
+ freq_threshold);
+ WARN(1, "timeout=0x%02x greater than 0x%02x. Using max\n",
+ timeout, mask >> shift);
+ timeout = mask >> shift;
}
+ /* Setup required timing */
+ pwr_mgmt_ctrl = (timeout << shift) & mask;
+ /* setup a default mask for rest of the modes */
+ pwr_mgmt_ctrl |= (SR_TIM_MASK | CS_TIM_MASK | PD_TIM_MASK) &
+ ~mask;
+
/* No CS_TIM in EMIF_4D5 */
if (ip_rev == EMIF_4D5)
pwr_mgmt_ctrl &= ~CS_TIM_MASK;