--- /dev/null
+/*
+ * 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;
+ 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 (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 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(dev_name(dev), 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;
+
+ 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] = clk_get(dev, clk_name);
+ if (IS_ERR(pd->asb_clk[i]))
+ break;
+ }
+
+ 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:
+ 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);
+ of_node_put(np);
+ }
+
+ return 0;
+}
+arch_initcall(exynos4_pm_init_power_domain);
Code Review / kvmfornfv.git / blobdiff