From 25aaacd2834233bbfa2b7ec697bfce42707e35b7 Mon Sep 17 00:00:00 2001 From: Nishanth Menon Date: Sat, 16 Mar 2013 11:46:43 +0530 Subject: [PATCH] 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 Signed-off-by: Lokesh Vutla Acked-by: Santosh Shilimkar Signed-off-by: Greg Kroah-Hartman --- drivers/memory/emif.c | 36 ++++++++++++++++++++++++++++-------- 1 file 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; -- 2.30.2