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Diffstat (limited to 'drivers/clk/samsung/clk-exynos-arm64.c')
-rw-r--r--drivers/clk/samsung/clk-exynos-arm64.c94
1 files changed, 94 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 000000000..b921b9a11
--- /dev/null
+++ b/drivers/clk/samsung/clk-exynos-arm64.c
@@ -0,0 +1,94 @@
+// 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 "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
+
+/**
+ * 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_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)
+{
+ /* Keep CMU parent clock running (needed for CMU registers access) */
+ if (cmu->clk_name) {
+ struct clk *parent_clk;
+
+ if (dev)
+ parent_clk = clk_get(dev, cmu->clk_name);
+ else
+ parent_clk = of_clk_get_by_name(np, cmu->clk_name);
+
+ if (IS_ERR(parent_clk)) {
+ pr_err("%s: could not find bus clock %s; err = %ld\n",
+ __func__, cmu->clk_name, PTR_ERR(parent_clk));
+ } else {
+ clk_prepare_enable(parent_clk);
+ }
+ }
+
+ exynos_arm64_init_clocks(np, cmu->clk_regs, cmu->nr_clk_regs);
+ samsung_cmu_register_one(np, cmu);
+}