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;
+}