There could be dependencies between various voltage domains for maintaining system performance or hardware limitation reasons like VDD<X> should be at voltage v1 when VDD<Y> is at voltage v2. This patch introduce dependent vdd information structures in the voltage layer which can be used to populate these dependencies for a voltage domain. This patch also adds support to scale the dependent vdd and the scalable devices belonging to it during the scaling of a main vdd through omap_voltage_scale.
Signed-off-by: Thara Gopinath <[email protected]> --- arch/arm/mach-omap2/voltage.c | 122 +++++++++++++++++++++++++++++++++++++++++ 1 files changed, 122 insertions(+), 0 deletions(-) diff --git a/arch/arm/mach-omap2/voltage.c b/arch/arm/mach-omap2/voltage.c index 458f8c1..67748b0 100644 --- a/arch/arm/mach-omap2/voltage.c +++ b/arch/arm/mach-omap2/voltage.c @@ -90,6 +90,36 @@ struct vp_reg_val { }; /** + * omap_vdd_dep_volt - Table containing the parent vdd voltage and the + * dependent vdd voltage corresponding to it. + * + * @main_vdd_volt : The main vdd voltage + * @dep_vdd_volt : The voltage at which the dependent vdd should be + * when the main vdd is at <main_vdd_volt> voltage + */ +struct omap_vdd_dep_volt { + u32 main_vdd_volt; + u32 dep_vdd_volt; +}; + +/** + * omap_vdd_dep_info - Dependent vdd info + * + * @name : Dependent vdd name + * @voltdm : Dependent vdd pointer + * @dep_table : Table containing the dependent vdd voltage + * corresponding to every main vdd voltage. + * @cur_dep_volt : The voltage to which dependent vdd should be put + * to for the current main vdd voltage. + */ +struct omap_vdd_dep_info{ + char *name; + struct voltagedomain *voltdm; + struct omap_vdd_dep_volt *dep_table; + unsigned long cur_dep_volt; +}; + +/** * struct omap_vdd_user_list - The per vdd user list * * @dev: The device asking for the vdd to be set at a particular @@ -135,12 +165,14 @@ struct omap_vdd_info{ struct vp_reg_offs vp_offs; struct vp_reg_val vp_reg; struct voltagedomain voltdm; + struct omap_vdd_dep_info *dep_vdd_info; struct dentry *debug_dir; spinlock_t user_lock; struct plist_head user_list; struct mutex scaling_mutex; struct list_head dev_list; int volt_data_count; + int nr_dep_vdd; u32 nominal_volt; u32 curr_volt; u8 cmdval_reg; @@ -1139,6 +1171,80 @@ static int vp_forceupdate_scale_voltage(struct omap_vdd_info *vdd, return 0; } +static int calc_dep_vdd_volt(struct device *dev, + struct omap_vdd_info *main_vdd, unsigned long main_volt) +{ + struct omap_vdd_dep_info *dep_vdds; + int i, ret = 0; + + if (!main_vdd->dep_vdd_info) { + pr_debug("%s: No dependent VDD's for vdd_%s\n", + __func__, main_vdd->voltdm.name); + return 0; + } + + dep_vdds = main_vdd->dep_vdd_info; + + for (i = 0; i < main_vdd->nr_dep_vdd; i++) { + struct omap_vdd_dep_volt *volt_table = dep_vdds[i].dep_table; + int nr_volt = 0; + unsigned long dep_volt = 0, act_volt = 0; + + while (volt_table[nr_volt].main_vdd_volt != 0) { + if (volt_table[nr_volt].main_vdd_volt == main_volt) { + dep_volt = volt_table[nr_volt].dep_vdd_volt; + break; + } + nr_volt++; + } + if (!dep_volt) { + pr_warning("%s: Not able to find a matching volt for" + "vdd_%s corresponding to vdd_%s %ld volt\n", + __func__, dep_vdds[i].name, + main_vdd->voltdm.name, main_volt); + ret = -EINVAL; + continue; + } + + if (!dep_vdds[i].voltdm) + dep_vdds[i].voltdm = + omap_voltage_domain_lookup(dep_vdds[i].name); + + act_volt = dep_volt; + + /* See if dep_volt is possible for the vdd*/ + ret = omap_voltage_add_request(dep_vdds[i].voltdm, dev, + &act_volt); + + /* + * Currently we do not bother if the dep volt and act volt are + * different. We could add a check if needed. + */ + dep_vdds[i].cur_dep_volt = act_volt; + } + + return ret; +} + +static int scale_dep_vdd(struct omap_vdd_info *main_vdd) +{ + struct omap_vdd_dep_info *dep_vdds; + int i; + + if (!main_vdd->dep_vdd_info) { + pr_debug("%s: No dependent VDD's for vdd_%s\n", + __func__, main_vdd->voltdm.name); + return 0; + } + + dep_vdds = main_vdd->dep_vdd_info; + + for (i = 0; i < main_vdd->nr_dep_vdd; i++) + omap_voltage_scale(dep_vdds[i].voltdm, + dep_vdds[i].cur_dep_volt); + return 0; +} + /* Public functions */ /** * omap_voltage_get_nom_volt() - Gets the current non-auto-compensated voltage @@ -1697,6 +1803,8 @@ int omap_voltage_scale(struct voltagedomain *voltdm, unsigned long volt) int is_volt_scaled = 0; struct omap_vdd_info *vdd; struct omap_vdd_dev_list *temp_dev; + struct plist_node *node; + struct omap_vdd_user_list *user; if (!voltdm || IS_ERR(voltdm)) { pr_warning("%s: VDD specified does not exist!\n", __func__); @@ -1709,6 +1817,17 @@ int omap_voltage_scale(struct voltagedomain *voltdm, unsigned long volt) curr_volt = omap_voltage_get_nom_volt(voltdm); + /* Find the device requesting the voltage scaling */ + node = plist_first(&vdd->user_list); + user = container_of(node, struct omap_vdd_user_list, node); + + /* calculate the voltages for dependent vdd's */ + if (calc_dep_vdd_volt(user->dev, vdd, volt)) { + pr_warning("%s: Error in calculating dependent vdd voltages" + "for vdd_%s\n", __func__, voltdm->name); + return -EINVAL; + } + if (curr_volt == volt) { is_volt_scaled = 1; } else if (curr_volt < volt) { @@ -1746,6 +1865,9 @@ int omap_voltage_scale(struct voltagedomain *voltdm, unsigned long volt) mutex_unlock(&vdd->scaling_mutex); + /* Scale dependent vdds */ + scale_dep_vdd(vdd); + return 0; } -- 1.7.0.4 -- 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
