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author | Krzysztof Kozlowski <k.kozlowski@samsung.com> | 2016-05-10 15:52:20 +0200 |
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committer | Krzysztof Kozlowski <k.kozlowski@samsung.com> | 2016-05-30 09:12:49 +0200 |
commit | e465007a7a7ca745f018fdcacb0a5a911a5c50d9 (patch) | |
tree | 008bb6b3b47e5d06fa2c7b94b5fe2220d0a29028 /drivers/soc/samsung/pm_domains.c | |
parent | 1a695a905c18548062509178b98bc91e67510864 (diff) | |
download | op-kernel-dev-e465007a7a7ca745f018fdcacb0a5a911a5c50d9.zip op-kernel-dev-e465007a7a7ca745f018fdcacb0a5a911a5c50d9.tar.gz |
ARM: EXYNOS: Move pm_domains driver to drivers/soc/samsung
Exynos PM domains driver does not have mach-specific dependencies so it
can be safely moved out of arm/mach-exynos to drivers/soc. This in
future will allow re-using it on ARM64 boards.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Diffstat (limited to 'drivers/soc/samsung/pm_domains.c')
-rw-r--r-- | drivers/soc/samsung/pm_domains.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/drivers/soc/samsung/pm_domains.c b/drivers/soc/samsung/pm_domains.c new file mode 100644 index 0000000..875a2ba --- /dev/null +++ b/drivers/soc/samsung/pm_domains.c @@ -0,0 +1,223 @@ +/* + * 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> + +#define INT_LOCAL_PWR_EN 0x7 +#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]; + struct clk *asb_clk[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; + int i; + + pd = container_of(domain, struct exynos_pm_domain, pd); + base = pd->base; + + for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) { + if (IS_ERR(pd->asb_clk[i])) + break; + clk_prepare_enable(pd->asb_clk[i]); + } + + /* Set oscclk before powering off a domain*/ + if (!power_on) { + for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) { + if (IS_ERR(pd->clk[i])) + break; + pd->pclk[i] = clk_get_parent(pd->clk[i]); + 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 ? INT_LOCAL_PWR_EN : 0; + __raw_writel(pwr, base); + + /* Wait max 1ms */ + timeout = 10; + + while ((__raw_readl(base + 0x4) & 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) { + for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) { + if (IS_ERR(pd->clk[i])) + break; + + if (IS_ERR(pd->pclk[i])) + continue; /* Skip on first power up */ + if (clk_set_parent(pd->clk[i], pd->pclk[i])) + pr_err("%s: error setting parent to clock%d\n", + pd->name, i); + } + } + + for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) { + if (IS_ERR(pd->asb_clk[i])) + break; + clk_disable_unprepare(pd->asb_clk[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 __init int exynos4_pm_init_power_domain(void) +{ + struct device_node *np; + + for_each_compatible_node(np, NULL, "samsung,exynos4210-pd") { + struct exynos_pm_domain *pd; + int on, i; + + pd = kzalloc(sizeof(*pd), GFP_KERNEL); + if (!pd) { + pr_err("%s: failed to allocate memory for domain\n", + __func__); + of_node_put(np); + return -ENOMEM; + } + pd->pd.name = kstrdup_const(strrchr(np->full_name, '/') + 1, + GFP_KERNEL); + if (!pd->pd.name) { + kfree(pd); + of_node_put(np); + return -ENOMEM; + } + + pd->name = pd->pd.name; + 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; + + for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) { + char clk_name[8]; + + snprintf(clk_name, sizeof(clk_name), "asb%d", i); + pd->asb_clk[i] = of_clk_get_by_name(np, clk_name); + if (IS_ERR(pd->asb_clk[i])) + break; + } + + pd->oscclk = of_clk_get_by_name(np, "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] = of_clk_get_by_name(np, clk_name); + if (IS_ERR(pd->clk[i])) + break; + /* + * Skip setting parent on first power up. + * The parent at this time may not be useful at all. + */ + pd->pclk[i] = ERR_PTR(-EINVAL); + } + + if (IS_ERR(pd->clk[0])) + clk_put(pd->oscclk); + +no_clk: + on = __raw_readl(pd->base + 0x4) & INT_LOCAL_PWR_EN; + + 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_compatible_node(np, NULL, "samsung,exynos4210-pd") { + struct generic_pm_domain *child_domain, *parent_domain; + struct of_phandle_args args; + + args.np = np; + args.args_count = 0; + child_domain = of_genpd_get_from_provider(&args); + if (IS_ERR(child_domain)) + continue; + + if (of_parse_phandle_with_args(np, "power-domains", + "#power-domain-cells", 0, &args) != 0) + continue; + + parent_domain = of_genpd_get_from_provider(&args); + if (IS_ERR(parent_domain)) + continue; + + if (pm_genpd_add_subdomain(parent_domain, child_domain)) + pr_warn("%s failed to add subdomain: %s\n", + parent_domain->name, child_domain->name); + else + pr_info("%s has as child subdomain: %s.\n", + parent_domain->name, child_domain->name); + } + + return 0; +} +core_initcall(exynos4_pm_init_power_domain); |