diff options
Diffstat (limited to 'drivers/soc/ti/ti_sci_pm_domains.c')
| -rw-r--r-- | drivers/soc/ti/ti_sci_pm_domains.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/drivers/soc/ti/ti_sci_pm_domains.c b/drivers/soc/ti/ti_sci_pm_domains.c new file mode 100644 index 000000000..de31b9389 --- /dev/null +++ b/drivers/soc/ti/ti_sci_pm_domains.c @@ -0,0 +1,204 @@ +/* + * TI SCI Generic Power Domain Driver + * + * Copyright (C) 2015-2017 Texas Instruments Incorporated - http://www.ti.com/ + * J Keerthy <j-keerthy@ti.com> + * Dave Gerlach <d-gerlach@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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/err.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/pm_domain.h> +#include <linux/slab.h> +#include <linux/soc/ti/ti_sci_protocol.h> + +/** + * struct ti_sci_genpd_dev_data: holds data needed for every device attached + * to this genpd + * @idx: index of the device that identifies it with the system + * control processor. + */ +struct ti_sci_genpd_dev_data { + int idx; +}; + +/** + * struct ti_sci_pm_domain: TI specific data needed for power domain + * @ti_sci: handle to TI SCI protocol driver that provides ops to + * communicate with system control processor. + * @dev: pointer to dev for the driver for devm allocs + * @pd: generic_pm_domain for use with the genpd framework + */ +struct ti_sci_pm_domain { + const struct ti_sci_handle *ti_sci; + struct device *dev; + struct generic_pm_domain pd; +}; + +#define genpd_to_ti_sci_pd(gpd) container_of(gpd, struct ti_sci_pm_domain, pd) + +/** + * ti_sci_dev_id(): get prepopulated ti_sci id from struct dev + * @dev: pointer to device associated with this genpd + * + * Returns device_id stored from ti,sci_id property + */ +static int ti_sci_dev_id(struct device *dev) +{ + struct generic_pm_domain_data *genpd_data = dev_gpd_data(dev); + struct ti_sci_genpd_dev_data *sci_dev_data = genpd_data->data; + + return sci_dev_data->idx; +} + +/** + * ti_sci_dev_to_sci_handle(): get pointer to ti_sci_handle + * @dev: pointer to device associated with this genpd + * + * Returns ti_sci_handle to be used to communicate with system + * control processor. + */ +static const struct ti_sci_handle *ti_sci_dev_to_sci_handle(struct device *dev) +{ + struct generic_pm_domain *pd = pd_to_genpd(dev->pm_domain); + struct ti_sci_pm_domain *ti_sci_genpd = genpd_to_ti_sci_pd(pd); + + return ti_sci_genpd->ti_sci; +} + +/** + * ti_sci_dev_start(): genpd device start hook called to turn device on + * @dev: pointer to device associated with this genpd to be powered on + */ +static int ti_sci_dev_start(struct device *dev) +{ + const struct ti_sci_handle *ti_sci = ti_sci_dev_to_sci_handle(dev); + int idx = ti_sci_dev_id(dev); + + return ti_sci->ops.dev_ops.get_device(ti_sci, idx); +} + +/** + * ti_sci_dev_stop(): genpd device stop hook called to turn device off + * @dev: pointer to device associated with this genpd to be powered off + */ +static int ti_sci_dev_stop(struct device *dev) +{ + const struct ti_sci_handle *ti_sci = ti_sci_dev_to_sci_handle(dev); + int idx = ti_sci_dev_id(dev); + + return ti_sci->ops.dev_ops.put_device(ti_sci, idx); +} + +static int ti_sci_pd_attach_dev(struct generic_pm_domain *domain, + struct device *dev) +{ + struct device_node *np = dev->of_node; + struct of_phandle_args pd_args; + struct ti_sci_pm_domain *ti_sci_genpd = genpd_to_ti_sci_pd(domain); + const struct ti_sci_handle *ti_sci = ti_sci_genpd->ti_sci; + struct ti_sci_genpd_dev_data *sci_dev_data; + struct generic_pm_domain_data *genpd_data; + int idx, ret = 0; + + ret = of_parse_phandle_with_args(np, "power-domains", + "#power-domain-cells", 0, &pd_args); + if (ret < 0) + return ret; + + if (pd_args.args_count != 1) + return -EINVAL; + + idx = pd_args.args[0]; + + /* + * Check the validity of the requested idx, if the index is not valid + * the PMMC will return a NAK here and we will not allocate it. + */ + ret = ti_sci->ops.dev_ops.is_valid(ti_sci, idx); + if (ret) + return -EINVAL; + + sci_dev_data = kzalloc(sizeof(*sci_dev_data), GFP_KERNEL); + if (!sci_dev_data) + return -ENOMEM; + + sci_dev_data->idx = idx; + + genpd_data = dev_gpd_data(dev); + genpd_data->data = sci_dev_data; + + return 0; +} + +static void ti_sci_pd_detach_dev(struct generic_pm_domain *domain, + struct device *dev) +{ + struct generic_pm_domain_data *genpd_data = dev_gpd_data(dev); + struct ti_sci_genpd_dev_data *sci_dev_data = genpd_data->data; + + kfree(sci_dev_data); + genpd_data->data = NULL; +} + +static const struct of_device_id ti_sci_pm_domain_matches[] = { + { .compatible = "ti,sci-pm-domain", }, + { }, +}; +MODULE_DEVICE_TABLE(of, ti_sci_pm_domain_matches); + +static int ti_sci_pm_domain_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct ti_sci_pm_domain *ti_sci_pd; + int ret; + + ti_sci_pd = devm_kzalloc(dev, sizeof(*ti_sci_pd), GFP_KERNEL); + if (!ti_sci_pd) + return -ENOMEM; + + ti_sci_pd->ti_sci = devm_ti_sci_get_handle(dev); + if (IS_ERR(ti_sci_pd->ti_sci)) + return PTR_ERR(ti_sci_pd->ti_sci); + + ti_sci_pd->dev = dev; + + ti_sci_pd->pd.name = "ti_sci_pd"; + + ti_sci_pd->pd.attach_dev = ti_sci_pd_attach_dev; + ti_sci_pd->pd.detach_dev = ti_sci_pd_detach_dev; + + ti_sci_pd->pd.dev_ops.start = ti_sci_dev_start; + ti_sci_pd->pd.dev_ops.stop = ti_sci_dev_stop; + + pm_genpd_init(&ti_sci_pd->pd, NULL, true); + + ret = of_genpd_add_provider_simple(np, &ti_sci_pd->pd); + + return ret; +} + +static struct platform_driver ti_sci_pm_domains_driver = { + .probe = ti_sci_pm_domain_probe, + .driver = { + .name = "ti_sci_pm_domains", + .of_match_table = ti_sci_pm_domain_matches, + }, +}; +module_platform_driver(ti_sci_pm_domains_driver); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("TI System Control Interface (SCI) Power Domain driver"); +MODULE_AUTHOR("Dave Gerlach"); |