Thara Gopinath <thara@xxxxxx> writes:
> This patch adds voltage driver support for OMAP3. The driver
> allows configuring the voltage controller and voltage
> processors during init and exports APIs to enable/disable
> voltage processors, scale voltage and reset voltage.
> The driver also maintains the global voltage table on a per
> VDD basis which contains the various voltages supported by the
> VDD along with per voltage dependent data like smartreflex
> n-target value, errminlimit and voltage processor errorgain.
> The driver allows scaling of VDD voltages either through
> "vc bypass method" or through "vp forceupdate method" the
> choice being configurable through the board file.
>
> This patch contains code originally in linux omap pm branch
> smartreflex driver. Major contributors to this driver are
> Lesly A M, Rajendra Nayak, Kalle Jokiniemi, Paul Walmsley,
> Nishant Menon, Kevin Hilman.
>
> Signed-off-by: Thara Gopinath <thara@xxxxxx>
[...]
> +static void vp_latch_vsel(struct omap_vdd_info *vdd)
> +{
> + u32 vpconfig;
> + unsigned long uvdc;
> + char vsel;
> +
> + uvdc = omap_voltage_get_nom_volt(&vdd->voltdm);
> + if (!uvdc) {
> + pr_warning("%s: unable to find current voltage for vdd_%s\n",
> + __func__, vdd->voltdm.name);
> + return;
> + }
> +
> + if (!volt_pmic_info.uv_to_vsel) {
> + pr_warning("%s: PMIC function to convert voltage in uV to"
> + " vsel not registered\n", __func__);
> + return;
> + }
Should return an error condition to the caller here...
> + vsel = volt_pmic_info.uv_to_vsel(uvdc);
> +
> + vpconfig = voltage_read_reg(vdd->vp_offs.vpconfig);
> + vpconfig &= ~(vdd->vp_reg.vpconfig_initvoltage_mask |
> + vdd->vp_reg.vpconfig_initvdd);
> + vpconfig |= vsel << vdd->vp_reg.vpconfig_initvoltage_shift;
> +
> + voltage_write_reg(vdd->vp_offs.vpconfig, vpconfig);
> +
> + /* Trigger initVDD value copy to voltage processor */
> + voltage_write_reg(vdd->vp_offs.vpconfig,
> + (vpconfig | vdd->vp_reg.vpconfig_initvdd));
> +
> + /* Clear initVDD copy trigger bit */
> + voltage_write_reg(vdd->vp_offs.vpconfig, vpconfig);
> +}
[...]
> +static void __init init_voltageprocessor(struct omap_vdd_info *vdd)
> +{
> + u32 vpconfig;
> +
> + vpconfig = vdd->vp_reg.vpconfig_erroroffset |
> + (vdd->vp_reg.vpconfig_errorgain <<
> + vdd->vp_reg.vpconfig_errorgain_shift) |
> + vdd->vp_reg.vpconfig_timeouten;
> +
> + voltage_write_reg(vdd->vp_offs.vpconfig, vpconfig);
> +
> + voltage_write_reg(vdd->vp_offs.vstepmin,
> + (vdd->vp_reg.vstepmin_smpswaittimemin <<
> + vdd->vp_reg.vstepmin_smpswaittimemin_shift) |
> + (vdd->vp_reg.vstepmin_stepmin <<
> + vdd->vp_reg.vstepmin_stepmin_shift));
> +
> + voltage_write_reg(vdd->vp_offs.vstepmax,
> + (vdd->vp_reg.vstepmax_smpswaittimemax <<
> + vdd->vp_reg.vstepmax_smpswaittimemax_shift) |
> + (vdd->vp_reg.vstepmax_stepmax <<
> + vdd->vp_reg.vstepmax_stepmax_shift));
> +
> + voltage_write_reg(vdd->vp_offs.vlimitto,
> + (vdd->vp_reg.vlimitto_vddmax <<
> + vdd->vp_reg.vlimitto_vddmax_shift) |
> + (vdd->vp_reg.vlimitto_vddmin <<
> + vdd->vp_reg.vlimitto_vddmin_shift) |
> + (vdd->vp_reg.vlimitto_timeout <<
> + vdd->vp_reg.vlimitto_timeout_shift));
> +
> + /* Set the init voltage */
> + vp_latch_vsel(vdd);
On OMAP4/panda, the boot hangs after this.
Since there is no PMIC registered, this call returns early but there is
no error checking done. I think the init needs a little more error
checking and graceful failure, especially when there is no PMIC present.
Kevin
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