diff options
Diffstat (limited to 'drivers/clk/samsung/clk-exynos-arm64.c')
| -rw-r--r-- | drivers/clk/samsung/clk-exynos-arm64.c | 94 |
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); +} |