diff options
Diffstat (limited to 'arch/arm/mach-exynos/pm_domains.c')
| -rw-r--r-- | arch/arm/mach-exynos/pm_domains.c | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/arch/arm/mach-exynos/pm_domains.c b/arch/arm/mach-exynos/pm_domains.c new file mode 100644 index 00000000000..797cb134bff --- /dev/null +++ b/arch/arm/mach-exynos/pm_domains.c @@ -0,0 +1,243 @@ +/* + * 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. + * + * 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/io.h> +#include <linux/err.h> +#include <linux/slab.h> +#include <linux/pm_domain.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/of_address.h> +#include <linux/of_platform.h> +#include <linux/sched.h> + +#include "regs-pmu.h" + +#define MAX_CLK_PER_DOMAIN 4 + +/* + * Exynos specific wrapper around the generic power domain + */ +struct exynos_pm_domain { + void __iomem *base; + char const *name; + bool is_off; + struct generic_pm_domain pd; + struct clk *oscclk; + struct clk *clk[MAX_CLK_PER_DOMAIN]; + struct clk *pclk[MAX_CLK_PER_DOMAIN]; +}; + +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; + + /* Set oscclk before powering off a domain*/ + if (!power_on) { + int i; + + for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) { + if (IS_ERR(pd->clk[i])) + break; + if (clk_set_parent(pd->clk[i], pd->oscclk)) + pr_err("%s: error setting oscclk as parent to clock %d\n", + pd->name, i); + } + } + + pwr = power_on ? S5P_INT_LOCAL_PWR_EN : 0; + __raw_writel(pwr, base); + + /* Wait max 1ms */ + timeout = 10; + + while ((__raw_readl(base + 0x4) & S5P_INT_LOCAL_PWR_EN) != 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); + } + + /* Restore clocks after powering on a domain*/ + if (power_on) { + int i; + + for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) { + if (IS_ERR(pd->clk[i])) + break; + if (clk_set_parent(pd->clk[i], pd->pclk[i])) + pr_err("%s: error setting parent to clock%d\n", + pd->name, i); + } + } + + 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 void exynos_add_device_to_domain(struct exynos_pm_domain *pd, + struct device *dev) +{ + int ret; + + dev_dbg(dev, "adding to power domain %s\n", pd->pd.name); + + while (1) { + ret = pm_genpd_add_device(&pd->pd, dev); + if (ret != -EAGAIN) + break; + cond_resched(); + } + + pm_genpd_dev_need_restore(dev, true); +} + +static void exynos_remove_device_from_domain(struct device *dev) +{ + struct generic_pm_domain *genpd = dev_to_genpd(dev); + int ret; + + dev_dbg(dev, "removing from power domain %s\n", genpd->name); + + while (1) { + ret = pm_genpd_remove_device(genpd, dev); + if (ret != -EAGAIN) + break; + cond_resched(); + } +} + +static void exynos_read_domain_from_dt(struct device *dev) +{ + struct platform_device *pd_pdev; + struct exynos_pm_domain *pd; + struct device_node *node; + + node = of_parse_phandle(dev->of_node, "samsung,power-domain", 0); + if (!node) + return; + pd_pdev = of_find_device_by_node(node); + if (!pd_pdev) + return; + pd = platform_get_drvdata(pd_pdev); + exynos_add_device_to_domain(pd, dev); +} + +static int exynos_pm_notifier_call(struct notifier_block *nb, + unsigned long event, void *data) +{ + struct device *dev = data; + + switch (event) { + case BUS_NOTIFY_BIND_DRIVER: + if (dev->of_node) + exynos_read_domain_from_dt(dev); + + break; + + case BUS_NOTIFY_UNBOUND_DRIVER: + exynos_remove_device_from_domain(dev); + + break; + } + return NOTIFY_DONE; +} + +static struct notifier_block platform_nb = { + .notifier_call = exynos_pm_notifier_call, +}; + +static __init int exynos4_pm_init_power_domain(void) +{ + struct platform_device *pdev; + struct device_node *np; + + for_each_compatible_node(np, NULL, "samsung,exynos4210-pd") { + struct exynos_pm_domain *pd; + int on, i; + struct device *dev; + + pdev = of_find_device_by_node(np); + dev = &pdev->dev; + + pd = kzalloc(sizeof(*pd), GFP_KERNEL); + if (!pd) { + pr_err("%s: failed to allocate memory for domain\n", + __func__); + return -ENOMEM; + } + + pd->pd.name = kstrdup(np->name, GFP_KERNEL); + pd->name = pd->pd.name; + pd->base = of_iomap(np, 0); + pd->pd.power_off = exynos_pd_power_off; + pd->pd.power_on = exynos_pd_power_on; + pd->pd.of_node = np; + + pd->oscclk = clk_get(dev, "oscclk"); + if (IS_ERR(pd->oscclk)) + goto no_clk; + + for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) { + char clk_name[8]; + + snprintf(clk_name, sizeof(clk_name), "clk%d", i); + pd->clk[i] = clk_get(dev, clk_name); + if (IS_ERR(pd->clk[i])) + break; + snprintf(clk_name, sizeof(clk_name), "pclk%d", i); + pd->pclk[i] = clk_get(dev, clk_name); + if (IS_ERR(pd->pclk[i])) { + clk_put(pd->clk[i]); + pd->clk[i] = ERR_PTR(-EINVAL); + break; + } + } + + if (IS_ERR(pd->clk[0])) + clk_put(pd->oscclk); + +no_clk: + platform_set_drvdata(pdev, pd); + + on = __raw_readl(pd->base + 0x4) & S5P_INT_LOCAL_PWR_EN; + + pm_genpd_init(&pd->pd, NULL, !on); + } + + bus_register_notifier(&platform_bus_type, &platform_nb); + + return 0; +} +arch_initcall(exynos4_pm_init_power_domain); |