RE: [RFCv2 2/2] AM35x: voltage: Basic initialization

[Vishwanath Sripathy <vishwanath.bs@ti.com>]

> -----Original Message-----
> From: linux-omap-owner@vger.kernel.org [mailto:linux-omap-
> owner@vger.kernel.org] On Behalf Of Sanjeev Premi
> Sent: Wednesday, March 16, 2011 1:02 PM
> To: linux-omap@vger.kernel.org
> Cc: Sanjeev Premi
> Subject: [RFCv2 2/2] AM35x: voltage: Basic initialization
>
> This patch adds the basic initialization of voltage layer
> for AM35x. Since AM35x doesn't support voltage scaling,
> Many functions emply fucntions have been defined to plug
> into existing voltage layer.
>
> Signed-off-by: Sanjeev Premi <premi@ti.com>
> ---
>  arch/arm/mach-omap2/voltage.c |  110
> ++++++++++++++++++++++++++++++++++++++++-
>  1 files changed, 109 insertions(+), 1 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/voltage.c b/arch/arm/mach-
> omap2/voltage.c
> index 2017dc0..a82a55f 100644
> --- a/arch/arm/mach-omap2/voltage.c
> +++ b/arch/arm/mach-omap2/voltage.c
> @@ -260,6 +260,40 @@ static struct omap_vdd_info omap3_vdd_info[]
> = {
>
>  #define OMAP3_NR_SCALABLE_VDD ARRAY_SIZE(omap3_vdd_info)
>
> +/*
> + * AM35x VDD structures
> + *
> + * In AM35x there neither scalable voltage domain nor any hook-up
> with
> + * voltage controller/processor. However, when trying to re-use the
> hwmod
> + * database for OMAP3, definition of "core" voltage domain is
> necessary.
> + * Else, changes in hwmod data structures grow spirally.
> + *
> + * As a workaround, "core" voltage domain is defined below. The
> definition
> + * doesn't lead to any side-effects.
> + */
> +static struct omap_vdd_info am3517_vdd_info[] = {
> +        {
> +		.dep_vdd_info	= NULL,
> +		.nr_dep_vdd	= 0,
> +		.vp_enabled	= false,
> +
> +                .voltdm = {
> +                        .name = "mpu",
> +                },
> +        },
> +        {
> +		.dep_vdd_info	= NULL,
> +		.nr_dep_vdd	= 0,
> +		.vp_enabled	= false,
> +
> +                .voltdm = {
> +                        .name = "core",
> +                },
> +        },
> +};
> +
> +#define AM3517_NR_SCALABLE_VDD ARRAY_SIZE(am3517_vdd_info)
> +
>  /* OMAP4 VDD sturctures */
>  static struct omap_vdd_info omap4_vdd_info[] = {
>  	{
> @@ -374,6 +408,15 @@ static struct omap_volt_data
> omap44xx_vdd_core_volt_data[] = {
>  	VOLT_DATA_DEFINE(0, 0, 0, 0),
>  };
>
> +/* AM35x
> + *
> + * Fields related to SmartReflex and Voltage Processor are set to 0.
> + */
> +static struct omap_volt_data am35xx_vdd_volt_data[] = {
> +	VOLT_DATA_DEFINE(OMAP3430_VDD_MPU_OPP3_UV, 0x0, 0x0,
> 0x0),
> +	VOLT_DATA_DEFINE(0, 0, 0, 0),
> +};
> +
>  /* OMAP 3430 MPU Core VDD dependency table */
>  static struct omap_vdd_dep_volt omap34xx_vdd1_vdd2_data[] = {
>  	{.main_vdd_volt = 975000, .dep_vdd_volt = 1050000},
> @@ -399,6 +442,12 @@ static void (*vp_init) (struct omap_vdd_info
> *vdd);
>
>  static int (*vdd_data_configure) (struct omap_vdd_info *vdd);
>
> +static int volt_scale_nop (struct omap_vdd_info *vdd,
> +				unsigned long target_volt)
> +{
> +	return 0;
> +}
> +
>  static u32 omap3_voltage_read_reg(u16 mod, u8 offset)
>  {
>  	return omap2_prm_read_mod_reg(mod, offset);
> @@ -1019,6 +1068,45 @@ static int __init
> omap3_vdd_data_configure(struct omap_vdd_info *vdd)
>  	return 0;
>  }
>
> +/**
> + *Setup VDD related information for AM35x processors
> + */
> +static int __init am3517_vdd_data_configure(struct omap_vdd_info
> *vdd)
> +{
> +	if (!vdd->pmic_info) {
> +		pr_err("%s: PMIC info requried to configure vdd_%s not"
> +			"populated.Hence cannot initialize vdd_%s\n",
> +			__func__, vdd->voltdm.name, vdd-
> >voltdm.name);
> +		return -EINVAL;
> +	}
> +
> +	if (!strcmp(vdd->voltdm.name, "mpu") ||
> +		!strcmp(vdd->voltdm.name, "core")) {
> +		vdd->volt_data = am35xx_vdd_volt_data;
> +	} else {
> +		pr_warning("%s: vdd_%s does not exist in AM35x\n",
> +			__func__, vdd->voltdm.name);
> +		return -EINVAL;
> +	}
> +
> +	/* Generic voltage parameters */
> +	vdd->curr_volt		= OMAP3430_VDD_MPU_OPP3_UV;
> +	vdd->ocp_mod		= OCP_MOD;
> +	vdd->prm_irqst_reg	= OMAP3_PRM_IRQSTATUS_MPU_OFFSET;
> +	vdd->read_reg		= omap3_voltage_read_reg;
> +	vdd->write_reg		= omap3_voltage_write_reg;
> +	vdd->volt_scale		= volt_scale_nop;
> +
> +	/* Init the plist */
> +	spin_lock_init(&vdd->user_lock);
> +	plist_head_init(&vdd->user_list, &vdd->user_lock);
> +
> +	/* Init the DVFS mutex */
> +	mutex_init(&vdd->scaling_mutex);
> +
> +	return 0;
> +}
> +
>  /* OMAP4 specific voltage init functions */
>  static void __init omap4_vc_init(struct omap_vdd_info *vdd)
>  {
> @@ -1908,13 +1996,33 @@ int __init omap_voltage_late_init(void)
>  }
>
>  /**
> + * AM35x - Empty initialization of voltage controller
> + */
> +static void __init am3517_vc_init(struct omap_vdd_info *vdd)
> +{
> +}
> +
> +/**
> + * AM35x - Empty initialization of voltage processor
> + */
> +static void __init am3517_vp_init(struct omap_vdd_info *vdd)
> +{
> +}
> +
> +/**
>   * omap_voltage_early_init()- Volatage driver early init
>   */
>  static int __init omap_voltage_early_init(void)
>  {
>  	int i;
>
> -	if (cpu_is_omap34xx()) {
> +	if (cpu_is_omap3505() || cpu_is_omap3517()) {
> +		vdd_info		= am3517_vdd_info;
> +		nr_scalable_vdd		=
> AM3517_NR_SCALABLE_VDD;
As you have mentioned that there is no voltage scaling supported, then
shoudn't nr_scalable_vdd = 0?
If nr_scalable_vdd is 0, then you probably would not need any other TPS
specific changes in Voltage.c as VP and VC initialization itself is
skipped.

Vishwa
> +		vc_init			= am3517_vc_init;
> +		vp_init			= am3517_vp_init;
> +		vdd_data_configure	= am3517_vdd_data_configure;
> +	} else if (cpu_is_omap34xx()) {
>  		vdd_info = omap3_vdd_info;
>  		nr_scalable_vdd = OMAP3_NR_SCALABLE_VDD;
>  		vc_init = omap3_vc_init;
> --
> 1.7.2.2
>
> --
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