RE: [PATCH 15/16] OMAP3: PM: VP force update method of voltage scaling

Gopinath, Thara
2010-03-05T15:30:41Z

>>-----Original Message-----
>>From: Felipe Contreras [mailto:felipe.contreras@gmail.com]
>>Sent: Friday, March 05, 2010 8:57 PM
>>To: Gopinath, Thara
>>Cc: Kevin Hilman; linux-omap@vger.kernel.org; paul@pwsan.com; Menon, Nishanth; Cousson, Benoit;
>>Sripathy, Vishwanath; Sawant, Anand
>>Subject: Re: [PATCH 15/16] OMAP3: PM: VP force update method of voltage scaling
>>
>>Hi Thara,
>>
>>On Fri, Mar 5, 2010 at 5:22 PM, Gopinath, Thara <thara@ti.com> wrote:
>>> Will do this as V2
>>
>>Can you please remove the chunks of text you are not replying to in your mails?
>>
>>All the following text is just a waste of bandwidth, and time for
>>people that actually scroll down trying to find further comments. This
>>is a practice not only you, but other people have started to follow in
>>this mailing list and it's annoying me a bit.
>>
>>Cheers.

Hello Filipe

I have been putting "Regards Thara" at the end of my comments precisely so that people do not have to scroll down and waste their bandwidth. I have seen this as an accepted practice in the mailing list through observing mails from other experts.

Regards
Thara
>>
>>>>>
>>>>>> ---
>>>>>>  arch/arm/mach-omap2/voltage.c |  149 +++++++++++++++++++++++++++++++++++++++--
>>>>>>  arch/arm/mach-omap2/voltage.h |    1 +
>>>>>>  arch/arm/plat-omap/Kconfig    |   19 +++++
>>>>>>  3 files changed, 162 insertions(+), 7 deletions(-)
>>>>>>
>>>>>> diff --git a/arch/arm/mach-omap2/voltage.c b/arch/arm/mach-omap2/voltage.c
>>>>>> index 49167c0..4f325af 100644
>>>>>> --- a/arch/arm/mach-omap2/voltage.c
>>>>>> +++ b/arch/arm/mach-omap2/voltage.c
>>>>>> @@ -29,7 +29,8 @@
>>>>>>  #include "prm-regbits-34xx.h"
>>>>>>  #include "voltage.h"
>>>>>>
>>>>>> -#define VP_IDLE_TIMEOUT 200
>>>>>> +#define VP_IDLE_TIMEOUT    200
>>>>>> +#define VP_TRANXDONE_TIMEOUT       300
>>>>>>
>>>>>>  /*
>>>>>>   * OMAP3 Voltage controller SR parameters. TODO: Pass this info as part of
>>>>>> @@ -70,6 +71,7 @@ struct vp_reg_info {
>>>>>>     u32 vp_vddmin;
>>>>>>     u32 vp_vddmax;
>>>>>>     u32 vp_timeout;
>>>>>> +   u32 vp_tranxdone_status;
>>>>>>  };
>>>>>>  static struct vp_reg_info *vp_reg;
>>>>>>  /*
>>>>>> @@ -299,6 +301,8 @@ static void __init vp_reg_configure(int vp_id)
>>>>>>                                     OMAP3430_VDDMIN_SHIFT);
>>>>>>                     vp_reg[vp_id].vp_vddmax = (OMAP3_VP1_VLIMITTO_VDDMAX <<
>>>>>>                                     OMAP3430_VDDMAX_SHIFT);
>>>>>> +                   vp_reg[vp_id].vp_tranxdone_status =
>>>>>> +                                   OMAP3430_VP1_TRANXDONE_ST;
>>>>>>             } else if (vp_id == VP2) {
>>>>>>                     /*
>>>>>>                      * OMAP3430 has error gain varying btw higher and
>>>>>> @@ -312,6 +316,8 @@ static void __init vp_reg_configure(int vp_id)
>>>>>>                                     OMAP3430_VDDMIN_SHIFT);
>>>>>>                     vp_reg[vp_id].vp_vddmax = (OMAP3_VP2_VLIMITTO_VDDMAX <<
>>>>>>                                     OMAP3430_VDDMAX_SHIFT);
>>>>>> +                   vp_reg[vp_id].vp_tranxdone_status =
>>>>>> +                                   OMAP3430_VP2_TRANXDONE_ST;
>>>>>>             } else {
>>>>>>                     pr_warning("Voltage processor%d does not exisit\
>>>>>>                                     in OMAP3 \n", vp_id);
>>>>>> @@ -346,6 +352,131 @@ static void __init vp_reg_configure(int vp_id)
>>>>>>     /* TODO Extend this for OMAP4 ?? Or need a separate file  */
>>>>>>  }
>>>>>>
>>>>>> +#ifdef CONFIG_OMAP_VOLT_VPFORCEUPDATE
>>>>>> +/* VP force update method of voltage scaling */
>>>>>> +static int vp_forceupdate_scale_voltage(u32 vdd, u8 target_vsel,
>>>>>> +                           u8 current_vsel)
>>>>>> +{
>>>>>> +   u32 smps_steps = 0, smps_delay = 0;
>>>>>> +   u32 vpconfig;
>>>>>> +   int timeout = 0;
>>>>>> +   int vp_id = vdd - 1;
>>>>>> +
>>>>>> +   if (!((vdd == VDD1_OPP) || (vdd == VDD2_OPP))) {
>>>>>> +           pr_warning("Wrong vdd id passed to vp forceupdate\n");
>>>>>> +           return false;
>>>>>> +   }
>>>>>> +
>>>>>> +   smps_steps = abs(target_vsel - current_vsel);
>>>>>> +
>>>>>> +   /* OMAP3430 has errorgain varying btw higher and lower opp's */
>>>>>> +   if (cpu_is_omap34xx()) {
>>>>>> +           if (vdd == VDD1_OPP) {
>>>>>> +                   u32 vc_cmdval0;
>>>>>> +
>>>>>> +                   vc_cmdval0 = voltage_read_reg(vc_reg.vc_cmdval0_reg);
>>>>>> +                   vc_cmdval0 &= ~VC_CMD_ON_MASK;
>>>>>> +                   vc_cmdval0 |= (target_vsel << VC_CMD_ON_SHIFT);
>>>>>> +                   voltage_write_reg(vc_reg.vc_cmdval0_reg, vc_cmdval0);
>>>>>> +                   vp_reg[vp_id].vp_errorgain = (((get_vdd1_opp() > 2) ?
>>>>>> +                                   (OMAP3_VP_CONFIG_ERRORGAIN_HIGHOPP) :
>>>>>> +                                   (OMAP3_VP_CONFIG_ERRORGAIN_LOWOPP)) <<
>>>>>> +                                   OMAP3430_ERRORGAIN_SHIFT);
>>>>>> +           } else if (vdd == VDD2_OPP) {
>>>>>> +                   u32 vc_cmdval1;
>>>>>> +
>>>>>> +                   vc_cmdval1 = voltage_read_reg(vc_reg.vc_cmdval1_reg);
>>>>>> +                   vc_cmdval1 &= ~VC_CMD_ON_MASK;
>>>>>> +                   vc_cmdval1 |= (target_vsel << VC_CMD_ON_SHIFT);
>>>>>> +                   voltage_write_reg(vc_reg.vc_cmdval1_reg, vc_cmdval1);
>>>>>> +                   vp_reg[vp_id].vp_errorgain = (((get_vdd2_opp() > 2) ?
>>>>>> +                                   (OMAP3_VP_CONFIG_ERRORGAIN_HIGHOPP) :
>>>>>> +                                   (OMAP3_VP_CONFIG_ERRORGAIN_LOWOPP)) <<
>>>>>> +                                   OMAP3430_ERRORGAIN_SHIFT);
>>>>>> +           }
>>>>>> +   }
>>>>>> +
>>>>>> +   /* Clear all pending TransactionDone interrupt/status. Typical latency
>>>>>> +    * is <3us
>>>>>> +    */
>>>>>> +   while (timeout++ < VP_TRANXDONE_TIMEOUT) {
>>>>>> +           voltage_write_reg(PRM_IRQSTATUS_REG,
>>>>>> +                           vp_reg[vp_id].vp_tranxdone_status);
>>>>>> +           if (!(voltage_read_reg(PRM_IRQSTATUS_REG) &
>>>>>> +                           vp_reg[vp_id].vp_tranxdone_status))
>>>>>> +                           break;
>>>>>> +           udelay(1);
>>>>>> +   }
>>>>>> +
>>>>>> +   if (timeout >= VP_TRANXDONE_TIMEOUT) {
>>>>>> +           pr_warning("VP%d TRANXDONE timeout exceeded. Voltage change \
>>>>>> +                           aborted", vdd);
>>>>>> +           return false;
>>>>>> +   }
>>>>>> +
>>>>>> +   /* Configure for VP-Force Update */
>>>>>> +   vpconfig = voltage_read_reg(vp_reg[vp_id].vp_offs.vp_vpconfig_reg);
>>>>>> +   vpconfig &= ~(VP_CONFIG_INITVDD | VP_FORCEUPDATE |
>>>>>> +                   VP_INITVOLTAGE_MASK | VP_ERRORGAIN_MASK);
>>>>>> +   vpconfig |= ((target_vsel << VP_INITVOLTAGE_SHIFT) |
>>>>>> +                   vp_reg[vp_id].vp_errorgain);
>>>>>> +   voltage_write_reg(vp_reg[vp_id].vp_offs.vp_vpconfig_reg, vpconfig);
>>>>>> +
>>>>>> +   /* Trigger initVDD value copy to voltage processor */
>>>>>> +   vpconfig |= VP_CONFIG_INITVDD;
>>>>>> +   voltage_write_reg(vp_reg[vp_id].vp_offs.vp_vpconfig_reg, vpconfig);
>>>>>> +
>>>>>> +   /* Force update of voltage */
>>>>>> +   vpconfig |= VP_FORCEUPDATE;
>>>>>> +   voltage_write_reg(vp_reg[vp_id].vp_offs.vp_vpconfig_reg, vpconfig);
>>>>>> +
>>>>>> +   timeout = 0;
>>>>>> +   /* Wait for TransactionDone. Typical latency is <200us.
>>>>>> +    * Depends on SMPSWAITTIMEMIN/MAX and voltage change
>>>>>> +    */
>>>>>
>>>>>multi-line comment style
>>>>>
>>>>>> +   while ((timeout++ < VP_TRANXDONE_TIMEOUT) &&
>>>>>> +                   (!(voltage_read_reg(PRM_IRQSTATUS_REG) &
>>>>>> +                   vp_reg[vp_id].vp_tranxdone_status)))
>>>>>> +           udelay(1);
>>>>>> +
>>>>>> +   if (timeout >= VP_TRANXDONE_TIMEOUT)
>>>>>> +           pr_warning("VP%d TRANXDONE timeout exceeded. TRANXDONE never \
>>>>>> +                   got set after the voltage update.Serious error!!!!\n",
>>>>>> +                   vdd);
>>>>>> +
>>>>>> +   /* Wait for voltage to settle with SW wait-loop */
>>>>>> +   smps_delay = ((smps_steps * 125) / 40) + 2;
>>>>>> +   udelay(smps_delay);
>>>>>> +
>>>>>> +   /* Disable TransactionDone interrupt , clear all status, clear
>>>>>> +    * control registers
>>>>>> +    */
>>>>>
>>>>>muti-line comment
>>>>>
>>>>>> +   timeout = 0;
>>>>>> +   while (timeout++ < VP_TRANXDONE_TIMEOUT) {
>>>>>> +           voltage_write_reg(PRM_IRQSTATUS_REG,
>>>>>> +                           vp_reg[vp_id].vp_tranxdone_status);
>>>>>> +           if (!(voltage_read_reg(PRM_IRQSTATUS_REG) &
>>>>>> +                           vp_reg[vp_id].vp_tranxdone_status))
>>>>>> +                           break;
>>>>>> +           udelay(1);
>>>>>> +   }
>>>>>> +   if (timeout >= VP_TRANXDONE_TIMEOUT)
>>>>>> +           pr_warning("VP%d TRANXDONE timeout exceeded while trying to \
>>>>>> +                   clear the TRANXDONE status\n", vdd);
>>>>>> +
>>>>>> +   vpconfig = voltage_read_reg(vp_reg[vp_id].vp_offs.vp_vpconfig_reg);
>>>>>> +   /* Clear initVDD copy trigger bit */
>>>>>> +   vpconfig &= ~VP_CONFIG_INITVDD;
>>>>>> +   voltage_write_reg(vp_reg[vp_id].vp_offs.vp_vpconfig_reg, vpconfig);
>>>>>> +   /* Clear force bit */
>>>>>> +   vpconfig &= ~VP_FORCEUPDATE;
>>>>>> +   voltage_write_reg(vp_reg[vp_id].vp_offs.vp_vpconfig_reg, vpconfig);
>>>>>> +
>>>>>> +   return true;
>>>>>> +}
>>>>>> +#endif
>>>>>> +
>>>>>> +#ifdef CONFIG_OMAP_VOLT_VCBYPASS
>>>>>>  /**
>>>>>>   * vc_bypass_scale_voltage - VC bypass method of voltage scaling
>>>>>>   */
>>>>>> @@ -437,7 +568,7 @@ static int vc_bypass_scale_voltage(u32 vdd, u8 target_vsel, u8 current_vsel)
>>>>>>     udelay(smps_delay);
>>>>>>     return true;
>>>>>>  }
>>>>>> -
>>>>>> +#endif
>>>>>>
>>>>>>  static void __init init_voltageprocessors(void)
>>>>>>  {
>>>>>> @@ -474,13 +605,16 @@ void omap_voltageprocessor_enable(int vp_id)
>>>>>>     if (voltage_read_reg(vp_reg[vp_id - 1].vp_offs.vp_vpconfig_reg) &
>>>>>>                             VP_CONFIG_VPENABLE)
>>>>>>             return;
>>>>>> +
>>>>>> +#ifdef CONFIG_OMAP_VOLT_VCBYPASS
>>>>>>     /*
>>>>>>      * This latching is required only if VC bypass method is used for
>>>>>>      * voltage scaling during dvfs.
>>>>>>      */
>>>>>>     vp_latch_vsel(vp_id - 1);
>>>>>> -   vpconfig = voltage_read_reg(vp_reg[vp_id - 1].vp_offs.vp_vpconfig_reg);
>>>>>> +#endif
>>>>>>     /* Enable VP */
>>>>>> +   vpconfig = voltage_read_reg(vp_reg[vp_id - 1].vp_offs.vp_vpconfig_reg);
>>>>>>     voltage_write_reg(vp_reg[vp_id - 1].vp_offs.vp_vpconfig_reg,
>>>>>>                             vpconfig | VP_CONFIG_VPENABLE);
>>>>>>  }
>>>>>> @@ -529,11 +663,12 @@ void omap_voltageprocessor_disable(int vp_id)
>>>>>>   * for a particular voltage domain during dvfs or any other situation.
>>>>>>   */
>>>>>>  int omap_voltage_scale(int vdd, u8 target_vsel, u8 current_vsel)
>>>>>> -{  /*
>>>>>> -    * TODO add VP force update method of voltage scaling
>>>>>> -    * and choose btw the two
>>>>>> -    */
>>>>>> +{
>>>>>> +#ifdef CONFIG_OMAP_VOLT_VCBYPASS
>>>>>>     return vc_bypass_scale_voltage(vdd, target_vsel, current_vsel);
>>>>>> +#elif CONFIG_OMAP_VOLT_VPFORCEUPDATE
>>>>>> +   return vp_forceupdate_scale_voltage(vdd, target_vsel, current_vsel);
>>>>>> +#endif
>>>>>>  }
>>>>>>
>>>>>>  /**
>>>>>> diff --git a/arch/arm/mach-omap2/voltage.h b/arch/arm/mach-omap2/voltage.h
>>>>>> index c3203c9..615bde6 100644
>>>>>> --- a/arch/arm/mach-omap2/voltage.h
>>>>>> +++ b/arch/arm/mach-omap2/voltage.h
>>>>>> @@ -17,6 +17,7 @@
>>>>>>  extern int get_vdd1_opp(void);
>>>>>>  extern int get_vdd2_opp(void);
>>>>>>
>>>>>> +#define PRM_IRQSTATUS_REG  OMAP3430_PRM_IRQSTATUS_MPU
>>>>>>  /* Generic VP definitions. Need to be redefined for OMAP4 */
>>>>>>  #define VP_CONFIG_TIMEOUTEN        OMAP3430_TIMEOUTEN
>>>>>>  #define VP_CONFIG_INITVDD  OMAP3430_INITVDD
>>>>>> diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig
>>>>>> index 9d286e6..1a611a9 100644
>>>>>> --- a/arch/arm/plat-omap/Kconfig
>>>>>> +++ b/arch/arm/plat-omap/Kconfig
>>>>>> @@ -92,6 +92,25 @@ config OMAP_SMARTREFLEX_TESTING
>>>>>>
>>>>>>       WARNING: Enabling this option may cause your device to hang!
>>>>>>
>>>>>> +choice
>>>>>> +   prompt "Choose Voltage Scale method"
>>>>>> +   depends on ARCH_OMAP3 && PM
>>>>>> +   default OMAP_VOLT_VPFORCEUPDATE
>>>>>> +
>>>>>> +config OMAP_VOLT_VPFORCEUPDATE
>>>>>> +   bool "Voltage scaling via VP force update method"
>>>>>> +   help
>>>>>> +    Say Y if you want to enable VP force update method
>>>>>> +    of voltage scaling. This is the h/w recomended way
>>>>>> +    of voltage scaling in OMAP3.
>>>>>> +
>>>>>> +config OMAP_VOLT_VCBYPASS
>>>>>> +   bool "Voltage Scale via Voltage controller in bypass"
>>>>>> +   help
>>>>>> +    Say Y if you want to enable VC Bypass method of voltage scaling.
>>>>>> +    Not the default recommended method.
>>>>>> +endchoice
>>>>>> +
>>>>>>  config OMAP_RESET_CLOCKS
>>>>>>     bool "Reset unused clocks during boot"
>>>>>>     depends on ARCH_OMAP
>>>>>> --
>>>>>> 1.7.0.rc1.33.g07cf0f
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>>
>>
>>
>>--
>>Felipe Contreras