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Diffstat (limited to 'drivers/clk/samsung/clk-exynos-arm64.c')
-rw-r--r--drivers/clk/samsung/clk-exynos-arm64.c292
1 files changed, 292 insertions, 0 deletions
diff --git a/drivers/clk/samsung/clk-exynos-arm64.c b/drivers/clk/samsung/clk-exynos-arm64.c
new file mode 100644
index 0000000000..6fb7194df7
--- /dev/null
+++ b/drivers/clk/samsung/clk-exynos-arm64.c
@@ -0,0 +1,292 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021 Linaro Ltd.
+ * Copyright (C) 2021 Dávid Virág <virag.david003@gmail.com>
+ * Author: Sam Protsenko <semen.protsenko@linaro.org>
+ * Author: Dávid Virág <virag.david003@gmail.com>
+ *
+ * This file contains shared functions used by some arm64 Exynos SoCs,
+ * such as Exynos7885 or Exynos850 to register and init CMUs.
+ */
+#include <linux/clk.h>
+#include <linux/of_address.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+
+#include "clk-exynos-arm64.h"
+
+/* Gate register bits */
+#define GATE_MANUAL BIT(20)
+#define GATE_ENABLE_HWACG BIT(28)
+
+/* Gate register offsets range */
+#define GATE_OFF_START 0x2000
+#define GATE_OFF_END 0x2fff
+
+struct exynos_arm64_cmu_data {
+ struct samsung_clk_reg_dump *clk_save;
+ unsigned int nr_clk_save;
+ const struct samsung_clk_reg_dump *clk_suspend;
+ unsigned int nr_clk_suspend;
+
+ struct clk *clk;
+ struct clk **pclks;
+ int nr_pclks;
+
+ struct samsung_clk_provider *ctx;
+};
+
+/**
+ * exynos_arm64_init_clocks - Set clocks initial configuration
+ * @np: CMU device tree node with "reg" property (CMU addr)
+ * @reg_offs: Register offsets array for clocks to init
+ * @reg_offs_len: Number of register offsets in reg_offs array
+ *
+ * Set manual control mode for all gate clocks.
+ */
+static void __init exynos_arm64_init_clocks(struct device_node *np,
+ const unsigned long *reg_offs, size_t reg_offs_len)
+{
+ void __iomem *reg_base;
+ size_t i;
+
+ reg_base = of_iomap(np, 0);
+ if (!reg_base)
+ panic("%s: failed to map registers\n", __func__);
+
+ for (i = 0; i < reg_offs_len; ++i) {
+ void __iomem *reg = reg_base + reg_offs[i];
+ u32 val;
+
+ /* Modify only gate clock registers */
+ if (reg_offs[i] < GATE_OFF_START || reg_offs[i] > GATE_OFF_END)
+ continue;
+
+ val = readl(reg);
+ val |= GATE_MANUAL;
+ val &= ~GATE_ENABLE_HWACG;
+ writel(val, reg);
+ }
+
+ iounmap(reg_base);
+}
+
+/**
+ * exynos_arm64_enable_bus_clk - Enable parent clock of specified CMU
+ *
+ * @dev: Device object; may be NULL if this function is not being
+ * called from platform driver probe function
+ * @np: CMU device tree node
+ * @cmu: CMU data
+ *
+ * Keep CMU parent clock running (needed for CMU registers access).
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+static int __init exynos_arm64_enable_bus_clk(struct device *dev,
+ struct device_node *np, const struct samsung_cmu_info *cmu)
+{
+ struct clk *parent_clk;
+
+ if (!cmu->clk_name)
+ return 0;
+
+ if (dev) {
+ struct exynos_arm64_cmu_data *data;
+
+ parent_clk = clk_get(dev, cmu->clk_name);
+ data = dev_get_drvdata(dev);
+ if (data)
+ data->clk = parent_clk;
+ } else {
+ parent_clk = of_clk_get_by_name(np, cmu->clk_name);
+ }
+
+ if (IS_ERR(parent_clk))
+ return PTR_ERR(parent_clk);
+
+ return clk_prepare_enable(parent_clk);
+}
+
+static int __init exynos_arm64_cmu_prepare_pm(struct device *dev,
+ const struct samsung_cmu_info *cmu)
+{
+ struct exynos_arm64_cmu_data *data = dev_get_drvdata(dev);
+ int i;
+
+ data->clk_save = samsung_clk_alloc_reg_dump(cmu->clk_regs,
+ cmu->nr_clk_regs);
+ if (!data->clk_save)
+ return -ENOMEM;
+
+ data->nr_clk_save = cmu->nr_clk_regs;
+ data->clk_suspend = cmu->suspend_regs;
+ data->nr_clk_suspend = cmu->nr_suspend_regs;
+ data->nr_pclks = of_clk_get_parent_count(dev->of_node);
+ if (!data->nr_pclks)
+ return 0;
+
+ data->pclks = devm_kcalloc(dev, sizeof(struct clk *), data->nr_pclks,
+ GFP_KERNEL);
+ if (!data->pclks) {
+ kfree(data->clk_save);
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < data->nr_pclks; i++) {
+ struct clk *clk = of_clk_get(dev->of_node, i);
+
+ if (IS_ERR(clk)) {
+ kfree(data->clk_save);
+ while (--i >= 0)
+ clk_put(data->pclks[i]);
+ return PTR_ERR(clk);
+ }
+ data->pclks[i] = clk;
+ }
+
+ return 0;
+}
+
+/**
+ * exynos_arm64_register_cmu - Register specified Exynos CMU domain
+ * @dev: Device object; may be NULL if this function is not being
+ * called from platform driver probe function
+ * @np: CMU device tree node
+ * @cmu: CMU data
+ *
+ * Register specified CMU domain, which includes next steps:
+ *
+ * 1. Enable parent clock of @cmu CMU
+ * 2. Set initial registers configuration for @cmu CMU clocks
+ * 3. Register @cmu CMU clocks using Samsung clock framework API
+ */
+void __init exynos_arm64_register_cmu(struct device *dev,
+ struct device_node *np, const struct samsung_cmu_info *cmu)
+{
+ int err;
+
+ /*
+ * Try to boot even if the parent clock enablement fails, as it might be
+ * already enabled by bootloader.
+ */
+ err = exynos_arm64_enable_bus_clk(dev, np, cmu);
+ if (err)
+ pr_err("%s: could not enable bus clock %s; err = %d\n",
+ __func__, cmu->clk_name, err);
+
+ exynos_arm64_init_clocks(np, cmu->clk_regs, cmu->nr_clk_regs);
+ samsung_cmu_register_one(np, cmu);
+}
+
+/**
+ * exynos_arm64_register_cmu_pm - Register Exynos CMU domain with PM support
+ *
+ * @pdev: Platform device object
+ * @set_manual: If true, set gate clocks to manual mode
+ *
+ * It's a version of exynos_arm64_register_cmu() with PM support. Should be
+ * called from probe function of platform driver.
+ *
+ * Return: 0 on success, or negative error code on error.
+ */
+int __init exynos_arm64_register_cmu_pm(struct platform_device *pdev,
+ bool set_manual)
+{
+ const struct samsung_cmu_info *cmu;
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct exynos_arm64_cmu_data *data;
+ void __iomem *reg_base;
+ int ret;
+
+ cmu = of_device_get_match_data(dev);
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, data);
+
+ ret = exynos_arm64_cmu_prepare_pm(dev, cmu);
+ if (ret)
+ return ret;
+
+ /*
+ * Try to boot even if the parent clock enablement fails, as it might be
+ * already enabled by bootloader.
+ */
+ ret = exynos_arm64_enable_bus_clk(dev, NULL, cmu);
+ if (ret)
+ dev_err(dev, "%s: could not enable bus clock %s; err = %d\n",
+ __func__, cmu->clk_name, ret);
+
+ if (set_manual)
+ exynos_arm64_init_clocks(np, cmu->clk_regs, cmu->nr_clk_regs);
+
+ reg_base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(reg_base))
+ return PTR_ERR(reg_base);
+
+ data->ctx = samsung_clk_init(dev, reg_base, cmu->nr_clk_ids);
+
+ /*
+ * Enable runtime PM here to allow the clock core using runtime PM
+ * for the registered clocks. Additionally, we increase the runtime
+ * PM usage count before registering the clocks, to prevent the
+ * clock core from runtime suspending the device.
+ */
+ pm_runtime_get_noresume(dev);
+ pm_runtime_set_active(dev);
+ pm_runtime_enable(dev);
+
+ samsung_cmu_register_clocks(data->ctx, cmu);
+ samsung_clk_of_add_provider(dev->of_node, data->ctx);
+ pm_runtime_put_sync(dev);
+
+ return 0;
+}
+
+int exynos_arm64_cmu_suspend(struct device *dev)
+{
+ struct exynos_arm64_cmu_data *data = dev_get_drvdata(dev);
+ int i;
+
+ samsung_clk_save(data->ctx->reg_base, data->clk_save,
+ data->nr_clk_save);
+
+ for (i = 0; i < data->nr_pclks; i++)
+ clk_prepare_enable(data->pclks[i]);
+
+ /* For suspend some registers have to be set to certain values */
+ samsung_clk_restore(data->ctx->reg_base, data->clk_suspend,
+ data->nr_clk_suspend);
+
+ for (i = 0; i < data->nr_pclks; i++)
+ clk_disable_unprepare(data->pclks[i]);
+
+ clk_disable_unprepare(data->clk);
+
+ return 0;
+}
+
+int exynos_arm64_cmu_resume(struct device *dev)
+{
+ struct exynos_arm64_cmu_data *data = dev_get_drvdata(dev);
+ int i;
+
+ clk_prepare_enable(data->clk);
+
+ for (i = 0; i < data->nr_pclks; i++)
+ clk_prepare_enable(data->pclks[i]);
+
+ samsung_clk_restore(data->ctx->reg_base, data->clk_save,
+ data->nr_clk_save);
+
+ for (i = 0; i < data->nr_pclks; i++)
+ clk_disable_unprepare(data->pclks[i]);
+
+ return 0;
+}