From 1e832e51018e960ecfc6f04abb1cbdd1ed82b8cb Mon Sep 17 00:00:00 2001 From: Tomasz Figa Date: Tue, 24 Jun 2014 18:08:26 +0200 Subject: [PATCH] clk: samsung: Add driver to control CLKOUT line on Exynos SoCs This patch introduces a driver that handles configuration of CLKOUT pin of Exynos SoCs that can be used to output certain clocks from inside of the SoC to a dedicated output pin. Signed-off-by: Tomasz Figa --- .../devicetree/bindings/arm/samsung/pmu.txt | 30 ++++ drivers/clk/samsung/Makefile | 1 + drivers/clk/samsung/clk-exynos-clkout.c | 153 ++++++++++++++++++ 3 files changed, 184 insertions(+) create mode 100644 drivers/clk/samsung/clk-exynos-clkout.c diff --git a/Documentation/devicetree/bindings/arm/samsung/pmu.txt b/Documentation/devicetree/bindings/arm/samsung/pmu.txt index 2a4ab046a8a..f9865e77e0b 100644 --- a/Documentation/devicetree/bindings/arm/samsung/pmu.txt +++ b/Documentation/devicetree/bindings/arm/samsung/pmu.txt @@ -12,8 +12,38 @@ Properties: - reg : offset and length of the register set. + - #clock-cells : must be <1>, since PMU requires once cell as clock specifier. + The single specifier cell is used as index to list of clocks + provided by PMU, which is currently: + 0 : SoC clock output (CLKOUT pin) + + - clock-names : list of clock names for particular CLKOUT mux inputs in + following format: + "clkoutN", where N is a decimal number corresponding to + CLKOUT mux control bits value for given input, e.g. + "clkout0", "clkout7", "clkout15". + + - clocks : list of phandles and specifiers to all input clocks listed in + clock-names property. + Example : pmu_system_controller: system-controller@10040000 { compatible = "samsung,exynos5250-pmu", "syscon"; reg = <0x10040000 0x5000>; + #clock-cells = <1>; + clock-names = "clkout0", "clkout1", "clkout2", "clkout3", + "clkout4", "clkout8", "clkout9"; + clocks = <&clock CLK_OUT_DMC>, <&clock CLK_OUT_TOP>, + <&clock CLK_OUT_LEFTBUS>, <&clock CLK_OUT_RIGHTBUS>, + <&clock CLK_OUT_CPU>, <&clock CLK_XXTI>, + <&clock CLK_XUSBXTI>; +}; + +Example of clock consumer : + +usb3503: usb3503@08 { + /* ... */ + clock-names = "refclk"; + clocks = <&pmu_system_controller 0>; + /* ... */ }; diff --git a/drivers/clk/samsung/Makefile b/drivers/clk/samsung/Makefile index 69e81773164..2949a556af8 100644 --- a/drivers/clk/samsung/Makefile +++ b/drivers/clk/samsung/Makefile @@ -11,6 +11,7 @@ obj-$(CONFIG_SOC_EXYNOS5410) += clk-exynos5410.o obj-$(CONFIG_SOC_EXYNOS5420) += clk-exynos5420.o obj-$(CONFIG_SOC_EXYNOS5440) += clk-exynos5440.o obj-$(CONFIG_ARCH_EXYNOS) += clk-exynos-audss.o +obj-$(CONFIG_ARCH_EXYNOS) += clk-exynos-clkout.o obj-$(CONFIG_S3C2410_COMMON_CLK)+= clk-s3c2410.o obj-$(CONFIG_S3C2410_COMMON_DCLK)+= clk-s3c2410-dclk.o obj-$(CONFIG_S3C2412_COMMON_CLK)+= clk-s3c2412.o diff --git a/drivers/clk/samsung/clk-exynos-clkout.c b/drivers/clk/samsung/clk-exynos-clkout.c new file mode 100644 index 00000000000..3a7cb250673 --- /dev/null +++ b/drivers/clk/samsung/clk-exynos-clkout.c @@ -0,0 +1,153 @@ +/* + * Copyright (c) 2014 Samsung Electronics Co., Ltd. + * Author: Tomasz Figa + * + * 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. + * + * Clock driver for Exynos clock output + */ + +#include +#include +#include +#include +#include +#include + +#define EXYNOS_CLKOUT_NR_CLKS 1 +#define EXYNOS_CLKOUT_PARENTS 32 + +#define EXYNOS_PMU_DEBUG_REG 0xa00 +#define EXYNOS_CLKOUT_DISABLE_SHIFT 0 +#define EXYNOS_CLKOUT_MUX_SHIFT 8 +#define EXYNOS4_CLKOUT_MUX_MASK 0xf +#define EXYNOS5_CLKOUT_MUX_MASK 0x1f + +struct exynos_clkout { + struct clk_gate gate; + struct clk_mux mux; + spinlock_t slock; + struct clk_onecell_data data; + struct clk *clk_table[EXYNOS_CLKOUT_NR_CLKS]; + void __iomem *reg; + u32 pmu_debug_save; +}; + +static struct exynos_clkout *clkout; + +static int exynos_clkout_suspend(void) +{ + clkout->pmu_debug_save = readl(clkout->reg + EXYNOS_PMU_DEBUG_REG); + + return 0; +} + +static void exynos_clkout_resume(void) +{ + writel(clkout->pmu_debug_save, clkout->reg + EXYNOS_PMU_DEBUG_REG); +} + +static struct syscore_ops exynos_clkout_syscore_ops = { + .suspend = exynos_clkout_suspend, + .resume = exynos_clkout_resume, +}; + +static void __init exynos_clkout_init(struct device_node *node, u32 mux_mask) +{ + const char *parent_names[EXYNOS_CLKOUT_PARENTS]; + struct clk *parents[EXYNOS_CLKOUT_PARENTS]; + int parent_count; + int ret; + int i; + + clkout = kzalloc(sizeof(*clkout), GFP_KERNEL); + if (!clkout) + return; + + spin_lock_init(&clkout->slock); + + parent_count = 0; + for (i = 0; i < EXYNOS_CLKOUT_PARENTS; ++i) { + char name[] = "clkoutXX"; + + snprintf(name, sizeof(name), "clkout%d", i); + parents[i] = of_clk_get_by_name(node, name); + if (IS_ERR(parents[i])) { + parent_names[i] = "none"; + continue; + } + + parent_names[i] = __clk_get_name(parents[i]); + parent_count = i + 1; + } + + if (!parent_count) + goto free_clkout; + + clkout->reg = of_iomap(node, 0); + if (!clkout->reg) + goto clks_put; + + clkout->gate.reg = clkout->reg + EXYNOS_PMU_DEBUG_REG; + clkout->gate.bit_idx = EXYNOS_CLKOUT_DISABLE_SHIFT; + clkout->gate.flags = CLK_GATE_SET_TO_DISABLE; + clkout->gate.lock = &clkout->slock; + + clkout->mux.reg = clkout->reg + EXYNOS_PMU_DEBUG_REG; + clkout->mux.mask = mux_mask; + clkout->mux.shift = EXYNOS_CLKOUT_MUX_SHIFT; + clkout->mux.lock = &clkout->slock; + + clkout->clk_table[0] = clk_register_composite(NULL, "clkout", + parent_names, parent_count, &clkout->mux.hw, + &clk_mux_ops, NULL, NULL, &clkout->gate.hw, + &clk_gate_ops, CLK_SET_RATE_PARENT + | CLK_SET_RATE_NO_REPARENT); + if (IS_ERR(clkout->clk_table[0])) + goto err_unmap; + + clkout->data.clks = clkout->clk_table; + clkout->data.clk_num = EXYNOS_CLKOUT_NR_CLKS; + ret = of_clk_add_provider(node, of_clk_src_onecell_get, &clkout->data); + if (ret) + goto err_clk_unreg; + + register_syscore_ops(&exynos_clkout_syscore_ops); + + return; + +err_clk_unreg: + clk_unregister(clkout->clk_table[0]); +err_unmap: + iounmap(clkout->reg); +clks_put: + for (i = 0; i < EXYNOS_CLKOUT_PARENTS; ++i) + if (!IS_ERR(parents[i])) + clk_put(parents[i]); +free_clkout: + kfree(clkout); + + pr_err("%s: failed to register clkout clock\n", __func__); +} + +static void __init exynos4_clkout_init(struct device_node *node) +{ + exynos_clkout_init(node, EXYNOS4_CLKOUT_MUX_MASK); +} +CLK_OF_DECLARE(exynos4210_clkout, "samsung,exynos4210-pmu", + exynos4_clkout_init); +CLK_OF_DECLARE(exynos4212_clkout, "samsung,exynos4212-pmu", + exynos4_clkout_init); +CLK_OF_DECLARE(exynos4412_clkout, "samsung,exynos4412-pmu", + exynos4_clkout_init); + +static void __init exynos5_clkout_init(struct device_node *node) +{ + exynos_clkout_init(node, EXYNOS5_CLKOUT_MUX_MASK); +} +CLK_OF_DECLARE(exynos5250_clkout, "samsung,exynos5250-pmu", + exynos5_clkout_init); +CLK_OF_DECLARE(exynos5420_clkout, "samsung,exynos5420-pmu", + exynos5_clkout_init); -- 2.41.0