diff options
Diffstat (limited to 'drivers/soc/samsung/pm_domains.c')
| -rw-r--r-- | drivers/soc/samsung/pm_domains.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/drivers/soc/samsung/pm_domains.c b/drivers/soc/samsung/pm_domains.c new file mode 100644 index 000000000..ab8582971 --- /dev/null +++ b/drivers/soc/samsung/pm_domains.c @@ -0,0 +1,168 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// Exynos Generic power domain support. +// +// Copyright (c) 2012 Samsung Electronics Co., Ltd. +// http://www.samsung.com +// +// Implementation of Exynos specific power domain control which is used in +// conjunction with runtime-pm. Support for both device-tree and non-device-tree +// based power domain support is included. + +#include <linux/io.h> +#include <linux/err.h> +#include <linux/slab.h> +#include <linux/pm_domain.h> +#include <linux/delay.h> +#include <linux/of_address.h> +#include <linux/of_platform.h> +#include <linux/sched.h> + +struct exynos_pm_domain_config { + /* Value for LOCAL_PWR_CFG and STATUS fields for each domain */ + u32 local_pwr_cfg; +}; + +/* + * Exynos specific wrapper around the generic power domain + */ +struct exynos_pm_domain { + void __iomem *base; + bool is_off; + struct generic_pm_domain pd; + u32 local_pwr_cfg; +}; + +static int exynos_pd_power(struct generic_pm_domain *domain, bool power_on) +{ + struct exynos_pm_domain *pd; + void __iomem *base; + u32 timeout, pwr; + char *op; + + pd = container_of(domain, struct exynos_pm_domain, pd); + base = pd->base; + + pwr = power_on ? pd->local_pwr_cfg : 0; + writel_relaxed(pwr, base); + + /* Wait max 1ms */ + timeout = 10; + + while ((readl_relaxed(base + 0x4) & pd->local_pwr_cfg) != pwr) { + if (!timeout) { + op = (power_on) ? "enable" : "disable"; + pr_err("Power domain %s %s failed\n", domain->name, op); + return -ETIMEDOUT; + } + timeout--; + cpu_relax(); + usleep_range(80, 100); + } + + return 0; +} + +static int exynos_pd_power_on(struct generic_pm_domain *domain) +{ + return exynos_pd_power(domain, true); +} + +static int exynos_pd_power_off(struct generic_pm_domain *domain) +{ + return exynos_pd_power(domain, false); +} + +static const struct exynos_pm_domain_config exynos4210_cfg __initconst = { + .local_pwr_cfg = 0x7, +}; + +static const struct exynos_pm_domain_config exynos5433_cfg __initconst = { + .local_pwr_cfg = 0xf, +}; + +static const struct of_device_id exynos_pm_domain_of_match[] __initconst = { + { + .compatible = "samsung,exynos4210-pd", + .data = &exynos4210_cfg, + }, { + .compatible = "samsung,exynos5433-pd", + .data = &exynos5433_cfg, + }, + { }, +}; + +static __init const char *exynos_get_domain_name(struct device_node *node) +{ + const char *name; + + if (of_property_read_string(node, "label", &name) < 0) + name = kbasename(node->full_name); + return kstrdup_const(name, GFP_KERNEL); +} + +static __init int exynos4_pm_init_power_domain(void) +{ + struct device_node *np; + const struct of_device_id *match; + + for_each_matching_node_and_match(np, exynos_pm_domain_of_match, &match) { + const struct exynos_pm_domain_config *pm_domain_cfg; + struct exynos_pm_domain *pd; + int on; + + pm_domain_cfg = match->data; + + pd = kzalloc(sizeof(*pd), GFP_KERNEL); + if (!pd) { + of_node_put(np); + return -ENOMEM; + } + pd->pd.name = exynos_get_domain_name(np); + if (!pd->pd.name) { + kfree(pd); + of_node_put(np); + return -ENOMEM; + } + + pd->base = of_iomap(np, 0); + if (!pd->base) { + pr_warn("%s: failed to map memory\n", __func__); + kfree_const(pd->pd.name); + kfree(pd); + continue; + } + + pd->pd.power_off = exynos_pd_power_off; + pd->pd.power_on = exynos_pd_power_on; + pd->local_pwr_cfg = pm_domain_cfg->local_pwr_cfg; + + on = readl_relaxed(pd->base + 0x4) & pd->local_pwr_cfg; + + pm_genpd_init(&pd->pd, NULL, !on); + of_genpd_add_provider_simple(np, &pd->pd); + } + + /* Assign the child power domains to their parents */ + for_each_matching_node(np, exynos_pm_domain_of_match) { + struct of_phandle_args child, parent; + + child.np = np; + child.args_count = 0; + + if (of_parse_phandle_with_args(np, "power-domains", + "#power-domain-cells", 0, + &parent) != 0) + continue; + + if (of_genpd_add_subdomain(&parent, &child)) + pr_warn("%pOF failed to add subdomain: %pOF\n", + parent.np, child.np); + else + pr_info("%pOF has as child subdomain: %pOF.\n", + parent.np, child.np); + } + + return 0; +} +core_initcall(exynos4_pm_init_power_domain); |