diff options
Diffstat (limited to 'arch/arm/mach-omap2/dvfs.c')
| -rw-r--r-- | arch/arm/mach-omap2/dvfs.c | 770 |
1 files changed, 770 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/dvfs.c b/arch/arm/mach-omap2/dvfs.c new file mode 100644 index 00000000000..fb9215cb927 --- /dev/null +++ b/arch/arm/mach-omap2/dvfs.c @@ -0,0 +1,770 @@ +/* + * OMAP3/OMAP4 DVFS Management Routines + * + * Author: Vishwanath BS <vishwanath.bs@ti.com> + * + * Copyright (C) 2011 Texas Instruments, Inc. + * Vishwanath BS <vishwanath.bs@ti.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/err.h> +#include <linux/spinlock.h> +#include <linux/plist.h> +#include <linux/slab.h> +#include <linux/opp.h> +#include <plat/common.h> +#include <plat/voltage.h> +#include <plat/omap_device.h> +#include <plat/smartreflex.h> + +/** + * struct omap_dev_user_list - Structure maitain userlist per device + * + * @dev: The device requesting for a particular frequency + * @node: The list head entry + * @freq: frequency being requested + * + * Using this structure, user list (requesting dev * and frequency) for + * each device is maintained. This is how we can have different devices + * at different frequencies (to support frequency locking and throttling). + * Even if one of the devices in a given vdd has locked it's frequency, + * other's can still scale their frequency using this list. + * If no one has placed a frequency request for a device, then device is + * set to the frequency from it's opp table. + */ +struct omap_dev_user_list { + struct device *dev; + struct plist_node node; + u32 freq; +}; + +/** + * struct omap_vdd_dev_list - Device list per vdd + * + * @dev: The device belonging to a particular vdd + * @node: The list head entry + */ +struct omap_vdd_dev_list { + struct device *dev; + struct list_head node; + struct plist_head user_list; + spinlock_t user_lock; /* spinlock for plist */ +}; + +/** + * struct omap_vdd_user_list - The per vdd user list + * + * @dev: The device asking for the vdd to be set at a particular + * voltage + * @node: The list head entry + * @volt: The voltage requested by the device <dev> + */ +struct omap_vdd_user_list { + struct device *dev; + struct plist_node node; + u32 volt; +}; + +/** + * struct omap_vdd_dvfs_info - The per vdd dvfs info + * + * @user_lock: spinlock for plist operations + * @user_list: The vdd user list + * @scaling_mutex: Mutex for protecting dvfs data structures for a vdd + * @voltdm: Voltage domains for which dvfs info stored + * + * This is a fundamental structure used to store all the required + * DVFS related information for a vdd. + */ +struct omap_vdd_dvfs_info { + spinlock_t user_lock; /* spin lock */ + struct plist_head user_list; + struct mutex scaling_mutex; /* dvfs mutex */ + struct voltagedomain *voltdm; + struct list_head dev_list; + struct device vdd_device; +}; + +static struct omap_vdd_dvfs_info *omap_dvfs_info_list; +static int omap_nr_vdd; + +static struct voltagedomain omap3_vdd[] = { + { + .name = "mpu", + }, + { + .name = "core", + }, +}; + +static struct voltagedomain omap4_vdd[] = { + { + .name = "mpu", + }, + { + .name = "iva", + }, + { + .name = "core", + }, +}; + +static int omap_dvfs_voltage_scale(struct omap_vdd_dvfs_info *dvfs_info); + +static int __init omap_dvfs_init(void); + +static struct omap_vdd_dvfs_info *get_dvfs_info(struct voltagedomain *voltdm) +{ + int i; + if (!voltdm || !omap_dvfs_info_list) + return NULL; + + for (i = 0; i < omap_nr_vdd; i++) + if (omap_dvfs_info_list[i].voltdm == voltdm) + return &omap_dvfs_info_list[i]; + + pr_warning("%s: unable find dvfs info for vdd %s\n", + __func__, voltdm->name); + return NULL; +} + +/** + * omap_dvfs_find_voltage() - search for given voltage + * @dev: device pointer associated with the opp type + * @volt: voltage to search for + * + * Searches for exact match in the opp list and returns handle to the matching + * opp if found, else returns ERR_PTR in case of error and should be handled + * using IS_ERR. If there are multiple opps with same voltage, it will return + * the first available entry. + */ +static struct opp *omap_dvfs_find_voltage(struct device *dev, + unsigned long volt) +{ + struct opp *opp = ERR_PTR(-ENODEV); + unsigned long f = 0; + + do { + opp = opp_find_freq_ceil(dev, &f); + if (IS_ERR(opp)) + break; + if (opp_get_voltage(opp) >= volt) + break; + f++; + } while (1); + + return opp; +} + +/** + * omap_dvfs_add_vdd_user() - Add a voltage request + * @dvfs_info: omap_vdd_dvfs_info pointer for the required vdd + * @dev: device making the request + * @volt: requesting voltage in uV + * + * Adds the given devices' voltage request into corresponding + * vdd's omap_vdd_dvfs_info user list (plist). This list is used + * to find the maximum voltage request for a given vdd. + * + * Returns 0 on success. + */ +static int omap_dvfs_add_vdd_user(struct omap_vdd_dvfs_info *dvfs_info, + struct device *dev, unsigned long volt) +{ + struct omap_vdd_user_list *user = NULL, *temp_user; + struct plist_node *node; + + if (!dvfs_info || IS_ERR(dvfs_info)) { + dev_warn(dev, "%s: VDD specified does not exist!\n", __func__); + return -EINVAL; + } + + mutex_lock(&dvfs_info->scaling_mutex); + + plist_for_each_entry(temp_user, &dvfs_info->user_list, node) { + if (temp_user->dev == dev) { + user = temp_user; + break; + } + } + + if (!user) { + user = kzalloc(sizeof(struct omap_vdd_user_list), GFP_KERNEL); + if (!user) { + dev_err(dev, "%s: Unable to creat a new user for vdd_%s\n", + __func__, dvfs_info->voltdm->name); + mutex_unlock(&dvfs_info->scaling_mutex); + return -ENOMEM; + } + user->dev = dev; + } else { + plist_del(&user->node, &dvfs_info->user_list); + } + + plist_node_init(&user->node, volt); + plist_add(&user->node, &dvfs_info->user_list); + node = plist_last(&dvfs_info->user_list); + user->volt = node->prio; + + mutex_unlock(&dvfs_info->scaling_mutex); + + return 0; +} + +/** + * omap_dvfs_remove_vdd_user() - Remove a voltage request + * @dvfs_info: omap_vdd_dvfs_info pointer for the required vdd + * @dev: device making the request + * + * Removes the given devices' voltage request from corresponding + * vdd's omap_vdd_dvfs_info user list (plist). + * + * Returns 0 on success. + */ +static int omap_dvfs_remove_vdd_user(struct omap_vdd_dvfs_info *dvfs_info, + struct device *dev) +{ + struct omap_vdd_user_list *user = NULL, *temp_user; + int ret = 0; + + if (!dvfs_info || IS_ERR(dvfs_info)) { + dev_err(dev, "%s: VDD specified does not exist!\n", __func__); + return -EINVAL; + } + + mutex_lock(&dvfs_info->scaling_mutex); + + plist_for_each_entry(temp_user, &dvfs_info->user_list, node) { + if (temp_user->dev == dev) { + user = temp_user; + break; + } + } + + if (user) + plist_del(&user->node, &dvfs_info->user_list); + else { + dev_err(dev, "%s: Unable to find the user for vdd_%s\n", + __func__, dvfs_info->voltdm->name); + ret = -ENOMEM; + } + mutex_unlock(&dvfs_info->scaling_mutex); + + return ret; +} + +/** + * omap_dvfs_register_device - Add a device into voltage domain + * @voltdm: voltage domain to which the device is to be added + * @dev: Device to be added + * + * This API will add a given device into user_list of corresponding + * vdd's omap_vdd_dvfs_info strucure. This list is traversed to scale + * frequencies of all the devices on a given vdd. This api is called + * while hwmod db is built for an omap_device. + * + * Returns 0 on success. + */ +int omap_dvfs_register_device(struct voltagedomain *voltdm, struct device *dev) +{ + struct omap_vdd_dev_list *temp_dev; + struct omap_vdd_dvfs_info *dvfs_info = get_dvfs_info(voltdm); + + if (!voltdm || IS_ERR(voltdm) || !dvfs_info) { + dev_warn(dev, "%s: VDD specified does not exist!\n", __func__); + return -EINVAL; + } + + list_for_each_entry(temp_dev, &dvfs_info->dev_list, node) { + if (temp_dev->dev == dev) { + dev_warn(dev, "%s: Device already added to vdee_%s\n", + __func__, dvfs_info->voltdm->name); + return -EINVAL; + } + } + + temp_dev = kzalloc(sizeof(struct omap_vdd_dev_list), GFP_KERNEL); + if (!temp_dev) { + dev_err(dev, "%s: Unable to creat a new device for vdd_%s\n", + __func__, dvfs_info->voltdm->name); + return -ENOMEM; + } + + /* Initialize priority ordered list */ + spin_lock_init(&temp_dev->user_lock); + plist_head_init(&temp_dev->user_list, &temp_dev->user_lock); + + temp_dev->dev = dev; + list_add(&temp_dev->node, &dvfs_info->dev_list); + + return 0; +} + +/** + * omap_dvfs_add_freq_request() - add a requested device frequency + * + * + * @dvfs_info: omap_vdd_dvfs_info pointer for the required vdd + * @req_dev: device making the request + * @target_dev: target device for which frequency request is being made + * @freq: target device frequency + * + * This API adds a requested frequency into target's device frequency list. + * + * Returns 0 on success. + */ +static int omap_dvfs_add_freq_request(struct omap_vdd_dvfs_info *dvfs_info, + struct device *req_dev, struct device *target_dev, unsigned long freq) +{ + struct omap_dev_user_list *dev_user = NULL, *tmp_user; + struct omap_vdd_dev_list *temp_dev; + + if (!dvfs_info || IS_ERR(dvfs_info)) { + dev_warn(target_dev, "%s: VDD specified does not exist!\n", + __func__); + return -EINVAL; + } + + mutex_lock(&dvfs_info->scaling_mutex); + + list_for_each_entry(temp_dev, &dvfs_info->dev_list, node) { + if (temp_dev->dev == target_dev) + break; + } + + if (temp_dev->dev != target_dev) { + dev_warn(target_dev, "%s: target_dev does not exist!\n", + __func__); + mutex_unlock(&dvfs_info->scaling_mutex); + return -EINVAL; + } + + plist_for_each_entry(tmp_user, &temp_dev->user_list, node) { + if (tmp_user->dev == req_dev) { + dev_user = tmp_user; + break; + } + } + + if (!dev_user) { + dev_user = kzalloc(sizeof(struct omap_dev_user_list), + GFP_KERNEL); + if (!dev_user) { + dev_err(target_dev, "%s: Unable to creat a new user for vdd_%s\n", + __func__, dvfs_info->voltdm->name); + mutex_unlock(&dvfs_info->scaling_mutex); + return -ENOMEM; + } + dev_user->dev = req_dev; + } else { + plist_del(&dev_user->node, &temp_dev->user_list); + } + + plist_node_init(&dev_user->node, freq); + plist_add(&dev_user->node, &temp_dev->user_list); + + mutex_unlock(&dvfs_info->scaling_mutex); + return 0; +} + +/** + * omap_dvfs_remove_freq_request() - Remove the requested device frequency + * + * @dvfs_info: omap_vdd_dvfs_info pointer for the required vdd + * @req_dev: device removing the request + * @target_dev: target device from which frequency request is being removed + * + * This API removes a requested frequency from target's device frequency list. + * + * Returns 0 on success. + */ + +static int omap_dvfs_remove_freq_request(struct omap_vdd_dvfs_info *dvfs_info, + struct device *req_dev, struct device *target_dev) +{ + struct omap_dev_user_list *dev_user = NULL, *tmp_user; + int ret = 0; + struct omap_vdd_dev_list *temp_dev; + + if (!dvfs_info || IS_ERR(dvfs_info)) { + dev_warn(target_dev, "%s: VDD specified does not exist!\n", + __func__); + return -EINVAL; + } + + mutex_lock(&dvfs_info->scaling_mutex); + + list_for_each_entry(temp_dev, &dvfs_info->dev_list, node) { + if (temp_dev->dev == target_dev) + break; + } + + if (temp_dev->dev != target_dev) { + dev_warn(target_dev, "%s: target_dev does not exist!\n", + __func__); + mutex_unlock(&dvfs_info->scaling_mutex); + return -EINVAL; + } + + plist_for_each_entry(tmp_user, &temp_dev->user_list, node) { + if (tmp_user->dev == req_dev) { + dev_user = tmp_user; + break; + } + } + + if (dev_user) + plist_del(&dev_user->node, &temp_dev->user_list); + else { + dev_err(target_dev, "%s: Unable to remove the user for vdd_%s\n", + __func__, dvfs_info->voltdm->name); + ret = -EINVAL; + } + + return ret; +} + +/* Calculate dependency vdd voltage for given vdd voltage */ +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_dvfs_add_vdd_user(get_dvfs_info(dep_vdds[i].voltdm), + dev, act_volt); + } + + return ret; +} + +/* Scale dependent VDD */ +static int scale_dep_vdd(struct omap_vdd_dvfs_info *vdd_info) +{ + struct omap_vdd_dep_info *dep_vdds; + int i; + struct omap_vdd_info *main_vdd; + struct voltagedomain *voltdm = vdd_info->voltdm; + main_vdd = container_of(voltdm, struct omap_vdd_info, voltdm); + + 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_dvfs_voltage_scale(get_dvfs_info(dep_vdds[i].voltdm)); + + return 0; +} + +/** + * omap_dvfs_voltage_scale() : API to scale the devices associated with a + * voltage domain vdd voltage. + * + * @dvfs_info: omap_vdd_dvfs_info pointer for the required vdd + * + * This API runs through the list of devices associated with the + * voltage domain and scales the device rates to the one requested + * by the user or those corresponding to the new voltage of the + * voltage domain. Target voltage is the highest voltage in the vdd_user_list. + * + * Returns 0 on success + * else the error value. + */ +static int omap_dvfs_voltage_scale(struct omap_vdd_dvfs_info *dvfs_info) +{ + unsigned long curr_volt; + int is_volt_scaled = 0; + struct omap_vdd_dev_list *temp_dev; + struct plist_node *node; + int ret = 0; + struct voltagedomain *voltdm; + unsigned long volt; + struct omap_vdd_info *vdd; + + if (!dvfs_info || IS_ERR(dvfs_info)) { + pr_warning("%s: VDD specified does not exist!\n", __func__); + return -EINVAL; + } + + voltdm = dvfs_info->voltdm; + vdd = container_of(voltdm, struct omap_vdd_info, voltdm); + + mutex_lock(&dvfs_info->scaling_mutex); + + /* Find the highest voltage being requested */ + node = plist_last(&dvfs_info->user_list); + volt = node->prio; + + curr_volt = omap_voltage_get_nom_volt(voltdm); + + /* Disable smartreflex module across voltage and frequency scaling */ + omap_sr_disable(voltdm); + + if (curr_volt == volt) { + is_volt_scaled = 1; + } else if (curr_volt < volt) { + ret = omap_voltage_scale_vdd(voltdm, volt); + if (ret) { + pr_warning("%s: Unable to scale the %s to %ld volt\n", + __func__, voltdm->name, volt); + omap_sr_enable(voltdm); + mutex_unlock(&dvfs_info->scaling_mutex); + return ret; + } + is_volt_scaled = 1; + } + + list_for_each_entry(temp_dev, &dvfs_info->dev_list, node) { + struct device *dev; + struct opp *opp; + unsigned long freq; + + dev = temp_dev->dev; + if (!plist_head_empty(&temp_dev->user_list)) { + node = plist_last(&temp_dev->user_list); + freq = node->prio; + } else { + opp = omap_dvfs_find_voltage(dev, volt); + if (IS_ERR(opp)) + continue; + freq = opp_get_freq(opp); + } + + if (freq == omap_device_get_rate(dev)) { + dev_dbg(dev, "%s: Already at the requested" + "rate %ld\n", __func__, freq); + continue; + } + + ret |= omap_device_set_rate(dev, freq); + } + + if (!is_volt_scaled && !ret) + omap_voltage_scale_vdd(voltdm, volt); + + /* Enable Smartreflex module */ + omap_sr_enable(voltdm); + + mutex_unlock(&dvfs_info->scaling_mutex); + + /* calculate the voltages for dependent vdd's */ + if (calc_dep_vdd_volt(&dvfs_info->vdd_device, vdd, volt)) { + pr_warning("%s: Error in calculating dependent vdd voltages" + "for vdd_%s\n", __func__, voltdm->name); + return -EINVAL; + } + + /* Scale dependent vdds */ + scale_dep_vdd(dvfs_info); + + return 0; +} + +/** + * omap_device_scale() - Set a new rate at which the device is to operate + * @req_dev: pointer to the device requesting the scaling. + * @target_dev: pointer to the device that is to be scaled + * @rate: the rnew rate for the device. + * + * This API gets the device opp table associated with this device and + * tries putting the device to the requested rate and the voltage domain + * associated with the device to the voltage corresponding to the + * requested rate. Since multiple devices can be assocciated with a + * voltage domain this API finds out the possible voltage the + * voltage domain can enter and then decides on the final device + * rate. Return 0 on success else the error value + */ +int omap_device_scale(struct device *req_dev, struct device *target_dev, + unsigned long rate) +{ + struct opp *opp; + unsigned long volt, freq, min_freq, max_freq; + struct omap_vdd_dvfs_info *dvfs_info; + struct platform_device *pdev; + struct omap_device *od; + int ret = 0; + + pdev = container_of(target_dev, struct platform_device, dev); + od = container_of(pdev, struct omap_device, pdev); + + /* + * Figure out if the desired frquency lies between the + * maximum and minimum possible for the particular device + */ + min_freq = 0; + if (IS_ERR(opp_find_freq_ceil(target_dev, &min_freq))) { + dev_err(target_dev, "%s: Unable to find lowest opp\n", + __func__); + return -ENODEV; + } + + max_freq = ULONG_MAX; + if (IS_ERR(opp_find_freq_floor(target_dev, &max_freq))) { + dev_err(target_dev, "%s: Unable to find highest opp\n", + __func__); + return -ENODEV; + } + + if (rate < min_freq) + freq = min_freq; + else if (rate > max_freq) + freq = max_freq; + else + freq = rate; + + opp = opp_find_freq_ceil(target_dev, &freq); + if (IS_ERR(opp)) { + dev_err(target_dev, "%s: Unable to find OPP for freq%ld\n", + __func__, rate); + return -ENODEV; + } + + /* Get the voltage corresponding to the requested frequency */ + volt = opp_get_voltage(opp); + + /* + * Call into the voltage layer to get the final voltage possible + * for the voltage domain associated with the device. + */ + + if (rate) { + dvfs_info = get_dvfs_info(od->hwmods[0]->voltdm); + + ret = omap_dvfs_add_freq_request(dvfs_info, req_dev, + target_dev, freq); + if (ret) { + dev_err(target_dev, "%s: Unable to add frequency request\n", + __func__); + return ret; + } + + ret = omap_dvfs_add_vdd_user(dvfs_info, req_dev, volt); + if (ret) { + dev_err(target_dev, "%s: Unable to add voltage request\n", + __func__); + omap_dvfs_remove_freq_request(dvfs_info, req_dev, + target_dev); + return ret; + } + } else { + dvfs_info = get_dvfs_info(od->hwmods[0]->voltdm); + + ret = omap_dvfs_remove_freq_request(dvfs_info, req_dev, + target_dev); + if (ret) { + dev_err(target_dev, "%s: Unable to remove frequency request\n", + __func__); + return ret; + } + + ret = omap_dvfs_remove_vdd_user(dvfs_info, req_dev); + if (ret) { + dev_err(target_dev, "%s: Unable to remove voltage request\n", + __func__); + return ret; + } + } + + /* Do the actual scaling */ + ret = omap_dvfs_voltage_scale(dvfs_info); + if (!ret) + if (omap_device_get_rate(target_dev) >= rate) + return 0; + + return ret; +} +EXPORT_SYMBOL(omap_device_scale); + +/** + * omap_dvfs_init() - Initialize omap dvfs layer + * + * Initalizes omap dvfs layer. It basically allocates memory for + * omap_dvfs_info_list and populates voltdm pointer inside + * omap_vdd_dvfs_info structure for all the VDDs. + * + * Returns 0 on success. + */ +static int __init omap_dvfs_init() +{ + int i; + struct voltagedomain *vdd_list; + if (cpu_is_omap34xx()) { + omap_nr_vdd = 2; + vdd_list = omap3_vdd; + } else if (cpu_is_omap44xx()) { + omap_nr_vdd = 3; + vdd_list = omap4_vdd; + } else { + pr_warning("DVFS not supported\n"); + return -EINVAL; + } + + omap_dvfs_info_list = kzalloc(omap_nr_vdd * + sizeof(struct omap_vdd_dvfs_info), GFP_KERNEL); + if (!omap_dvfs_info_list) { + pr_warning("%s: Unable to allocate memory for vdd_list", + __func__); + return -ENOMEM; + } + + for (i = 0; i < omap_nr_vdd; i++) { + omap_dvfs_info_list[i].voltdm = + omap_voltage_domain_lookup(vdd_list[i].name); + /* Init the plist */ + spin_lock_init(&omap_dvfs_info_list[i].user_lock); + plist_head_init(&omap_dvfs_info_list[i].user_list, + &omap_dvfs_info_list[i].user_lock); + /* Init the DVFS mutex */ + mutex_init(&omap_dvfs_info_list[i].scaling_mutex); + /* Init the device list */ + INIT_LIST_HEAD(&omap_dvfs_info_list[i].dev_list); + } + + return 0; +} +core_initcall(omap_dvfs_init); |