This patch removes the worst case T2 SMPS stabilization delay of 360 us (needed for a 0v to 1.35 switch) and adds calculated delay based on the actual volatge switch. The delay is based on the T2 SMPS slew rate of 4mV/uS. Each step based on VSEL difference corresponds to 12.5 mv
Hence the formula used: delay = (steps * 12.5)/4 + (2 us of buffer). This also adds a SMPS stabilization delay in the sr_reset_voltage() function which seems to be needed. Signed-off-by: Rajendra Nayak <[email protected]> --- arch/arm/mach-omap2/resource34xx.c | 9 ++++-- arch/arm/mach-omap2/resource34xx.h | 2 +- arch/arm/mach-omap2/smartreflex.c | 48 ++++++++++++++++++++++++++++------- arch/arm/mach-omap2/smartreflex.h | 2 +- 4 files changed, 46 insertions(+), 15 deletions(-) diff --git a/arch/arm/mach-omap2/resource34xx.c b/arch/arm/mach-omap2/resource34xx.c index 4c87436..82405b6 100644 --- a/arch/arm/mach-omap2/resource34xx.c +++ b/arch/arm/mach-omap2/resource34xx.c @@ -258,6 +258,7 @@ static int program_opp_freq(int res, int target_level, int current_level) #ifdef CONFIG_PM omap3_save_scratchpad_contents(); #endif + *curr_opp = target_level; return target_level; } @@ -267,9 +268,10 @@ static int program_opp(int res, struct omap_opp *opp, int target_level, { int i, ret = 0, raise; #ifdef CONFIG_OMAP_SMARTREFLEX - unsigned long t_opp; + unsigned long t_opp, c_opp; t_opp = ID_VDD(res) | ID_OPP_NO(opp[target_level].opp_id); + c_opp = ID_VDD(res) | ID_OPP_NO(opp[current_level].opp_id); #endif if (target_level > current_level) raise = 1; @@ -282,8 +284,9 @@ static int program_opp(int res, struct omap_opp *opp, int target_level, current_level); #ifdef CONFIG_OMAP_SMARTREFLEX else - sr_voltagescale_vcbypass(t_opp, - opp[target_level].vsel); + sr_voltagescale_vcbypass(t_opp, c_opp, + opp[target_level].vsel, + opp[current_level].vsel); #endif } diff --git a/arch/arm/mach-omap2/resource34xx.h b/arch/arm/mach-omap2/resource34xx.h index 8d95a00..a160665 100644 --- a/arch/arm/mach-omap2/resource34xx.h +++ b/arch/arm/mach-omap2/resource34xx.h @@ -28,7 +28,7 @@ #include <mach/omap-pm.h> #include <mach/omap34xx.h> -extern int sr_voltagescale_vcbypass(u32 target_opp, u8 vsel); +extern int sr_voltagescale_vcbypass(u32 t_opp, u32 c_opp, u8 t_vsel, u8 c_vsel); /* * mpu_latency/core_latency are used to control the cpuidle C state. diff --git a/arch/arm/mach-omap2/smartreflex.c b/arch/arm/mach-omap2/smartreflex.c index 422c917..a2fe00e 100644 --- a/arch/arm/mach-omap2/smartreflex.c +++ b/arch/arm/mach-omap2/smartreflex.c @@ -449,6 +449,9 @@ static int sr_reset_voltage(int srid) u32 reg_addr = 0; u32 loop_cnt = 0, retries_cnt = 0; u32 vc_bypass_value; + u32 t2_smps_steps = 0; + u32 t2_smps_delay = 0; + u32 prm_vp1_voltage, prm_vp2_voltage; if (srid == SR1) { target_opp_no = get_vdd1_opp(); @@ -458,6 +461,9 @@ static int sr_reset_voltage(int srid) } vsel = mpu_opps[target_opp_no].vsel; reg_addr = R_VDD1_SR_CONTROL; + prm_vp1_voltage = prm_read_mod_reg(OMAP3430_GR_MOD, + OMAP3_PRM_VP1_VOLTAGE_OFFSET); + t2_smps_steps = abs(vsel - prm_vp1_voltage); } else if (srid == SR2) { target_opp_no = get_vdd2_opp(); if (!target_opp_no) { @@ -466,6 +472,9 @@ static int sr_reset_voltage(int srid) } vsel = l3_opps[target_opp_no].vsel; reg_addr = R_VDD2_SR_CONTROL; + prm_vp2_voltage = prm_read_mod_reg(OMAP3430_GR_MOD, + OMAP3_PRM_VP2_VOLTAGE_OFFSET); + t2_smps_steps = abs(vsel - prm_vp2_voltage); } vc_bypass_value = (vsel << OMAP3430_DATA_SHIFT) | @@ -493,6 +502,14 @@ static int sr_reset_voltage(int srid) vc_bypass_value = prm_read_mod_reg(OMAP3430_GR_MOD, OMAP3_PRM_VC_BYPASS_VAL_OFFSET); } + + /* + * T2 SMPS slew rate (min) 4mV/uS, step size 12.5mV, + * 2us added as buffer. + */ + t2_smps_delay = ((t2_smps_steps * 125) / 40) + 2; + udelay(t2_smps_delay); + return 0; } @@ -751,37 +768,43 @@ void disable_smartreflex(int srid) } /* Voltage Scaling using SR VCBYPASS */ -int sr_voltagescale_vcbypass(u32 target_opp, u8 vsel) +int sr_voltagescale_vcbypass(u32 target_opp, u32 current_opp, + u8 target_vsel, u8 current_vsel) { int sr_status = 0; - u32 vdd, target_opp_no; + u32 vdd, target_opp_no, current_opp_no; u32 vc_bypass_value; u32 reg_addr = 0; u32 loop_cnt = 0, retries_cnt = 0; + u32 t2_smps_steps = 0; + u32 t2_smps_delay = 0; vdd = get_vdd(target_opp); target_opp_no = get_opp_no(target_opp); + current_opp_no = get_opp_no(current_opp); if (vdd == VDD1_OPP) { sr_status = sr_stop_vddautocomap(SR1); + t2_smps_steps = abs(target_vsel - current_vsel); prm_rmw_mod_reg_bits(OMAP3430_VC_CMD_ON_MASK, - (vsel << OMAP3430_VC_CMD_ON_SHIFT), - OMAP3430_GR_MOD, - OMAP3_PRM_VC_CMD_VAL_0_OFFSET); + (target_vsel << OMAP3430_VC_CMD_ON_SHIFT), + OMAP3430_GR_MOD, + OMAP3_PRM_VC_CMD_VAL_0_OFFSET); reg_addr = R_VDD1_SR_CONTROL; } else if (vdd == VDD2_OPP) { sr_status = sr_stop_vddautocomap(SR2); + t2_smps_steps = abs(target_vsel - current_vsel); prm_rmw_mod_reg_bits(OMAP3430_VC_CMD_ON_MASK, - (vsel << OMAP3430_VC_CMD_ON_SHIFT), - OMAP3430_GR_MOD, - OMAP3_PRM_VC_CMD_VAL_1_OFFSET); + (target_vsel << OMAP3430_VC_CMD_ON_SHIFT), + OMAP3430_GR_MOD, + OMAP3_PRM_VC_CMD_VAL_1_OFFSET); reg_addr = R_VDD2_SR_CONTROL; } - vc_bypass_value = (vsel << OMAP3430_DATA_SHIFT) | + vc_bypass_value = (target_vsel << OMAP3430_DATA_SHIFT) | (reg_addr << OMAP3430_REGADDR_SHIFT) | (R_SRI2C_SLAVE_ADDR << OMAP3430_SLAVEADDR_SHIFT); @@ -807,7 +830,12 @@ int sr_voltagescale_vcbypass(u32 target_opp, u8 vsel) OMAP3_PRM_VC_BYPASS_VAL_OFFSET); } - udelay(T2_SMPS_UPDATE_DELAY); + /* + * T2 SMPS slew rate (min) 4mV/uS, step size 12.5mV, + * 2us added as buffer. + */ + t2_smps_delay = ((t2_smps_steps * 125) / 40) + 2; + udelay(t2_smps_delay); if (sr_status) { if (vdd == VDD1_OPP) diff --git a/arch/arm/mach-omap2/smartreflex.h b/arch/arm/mach-omap2/smartreflex.h index 94e522b..2a0e823 100644 --- a/arch/arm/mach-omap2/smartreflex.h +++ b/arch/arm/mach-omap2/smartreflex.h @@ -245,7 +245,7 @@ extern u32 current_vdd2_opp; #ifdef CONFIG_OMAP_SMARTREFLEX void enable_smartreflex(int srid); void disable_smartreflex(int srid); -int sr_voltagescale_vcbypass(u32 target_opp, u8 vsel); +int sr_voltagescale_vcbypass(u32 t_opp, u32 c_opp, u8 t_vsel, u8 c_vsel); void sr_start_vddautocomap(int srid, u32 target_opp_no); int sr_stop_vddautocomap(int srid); #else -- 1.5.4.7 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
