Add a simple driver for the clocks provided by the MIPS Boston development board. The system provides information about 2 clocks whose rates are fixed by the bitfile flashed in the boards FPGA, and this driver simply reads the rates of these 2 clocks.
Signed-off-by: Paul Burton paul.burton@imgtec.com Reviewed-by: Simon Glass sjg@chromium.org
---
Changes in v7: None Changes in v6: None Changes in v5: None Changes in v4: - Replace EXT macro with ext_field function
Changes in v3: None Changes in v2: - New patch
drivers/clk/Kconfig | 8 +++ drivers/clk/Makefile | 1 + drivers/clk/clk_boston.c | 97 ++++++++++++++++++++++++++++++++ include/dt-bindings/clock/boston-clock.h | 13 +++++ 4 files changed, 119 insertions(+) create mode 100644 drivers/clk/clk_boston.c create mode 100644 include/dt-bindings/clock/boston-clock.h
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig index 8f3b96a..c05ce2a 100644 --- a/drivers/clk/Kconfig +++ b/drivers/clk/Kconfig @@ -20,6 +20,14 @@ config SPL_CLK setting up clocks within SPL, and allows the same drivers to be used as U-Boot proper.
+config CLK_BOSTON + def_bool y if TARGET_BOSTON + depends on CLK + select REGMAP + select SYSCON + help + Enable this to support the clocks + source "drivers/clk/tegra/Kconfig" source "drivers/clk/uniphier/Kconfig" source "drivers/clk/exynos/Kconfig" diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index 778d748..40a5e8c 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -15,3 +15,4 @@ obj-y += tegra/ obj-$(CONFIG_CLK_UNIPHIER) += uniphier/ obj-$(CONFIG_CLK_EXYNOS) += exynos/ obj-$(CONFIG_CLK_AT91) += at91/ +obj-$(CONFIG_CLK_BOSTON) += clk_boston.o diff --git a/drivers/clk/clk_boston.c b/drivers/clk/clk_boston.c new file mode 100644 index 0000000..78f1b75 --- /dev/null +++ b/drivers/clk/clk_boston.c @@ -0,0 +1,97 @@ +/* + * Copyright (C) 2016 Imagination Technologies + * + * SPDX-License-Identifier: GPL-2.0 + */ + +#include <common.h> +#include <clk-uclass.h> +#include <dm.h> +#include <dt-bindings/clock/boston-clock.h> +#include <regmap.h> +#include <syscon.h> + +struct clk_boston { + struct regmap *regmap; +}; + +#define BOSTON_PLAT_MMCMDIV 0x30 +# define BOSTON_PLAT_MMCMDIV_CLK0DIV (0xff << 0) +# define BOSTON_PLAT_MMCMDIV_INPUT (0xff << 8) +# define BOSTON_PLAT_MMCMDIV_MUL (0xff << 16) +# define BOSTON_PLAT_MMCMDIV_CLK1DIV (0xff << 24) + +static uint32_t ext_field(uint32_t val, uint32_t mask) +{ + return (val & mask) >> (ffs(mask) - 1); +} + +static ulong clk_boston_get_rate(struct clk *clk) +{ + struct clk_boston *state = dev_get_platdata(clk->dev); + uint32_t in_rate, mul, div; + uint mmcmdiv; + int err; + + err = regmap_read(state->regmap, BOSTON_PLAT_MMCMDIV, &mmcmdiv); + if (err) + return 0; + + in_rate = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_INPUT); + mul = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_MUL); + + switch (clk->id) { + case BOSTON_CLK_SYS: + div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK0DIV); + break; + case BOSTON_CLK_CPU: + div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK1DIV); + break; + default: + return 0; + } + + return (in_rate * mul * 1000000) / div; +} + +const struct clk_ops clk_boston_ops = { + .get_rate = clk_boston_get_rate, +}; + +static int clk_boston_ofdata_to_platdata(struct udevice *dev) +{ + struct clk_boston *state = dev_get_platdata(dev); + struct udevice *syscon; + int err; + + err = uclass_get_device_by_phandle(UCLASS_SYSCON, dev, + "regmap", &syscon); + if (err) { + error("unable to find syscon device\n"); + return err; + } + + state->regmap = syscon_get_regmap(syscon); + if (!state->regmap) { + error("unable to find regmap\n"); + return -ENODEV; + } + + return 0; +} + +static const struct udevice_id clk_boston_match[] = { + { + .compatible = "img,boston-clock", + }, + { /* sentinel */ } +}; + +U_BOOT_DRIVER(clk_boston) = { + .name = "boston_clock", + .id = UCLASS_CLK, + .of_match = clk_boston_match, + .ofdata_to_platdata = clk_boston_ofdata_to_platdata, + .platdata_auto_alloc_size = sizeof(struct clk_boston), + .ops = &clk_boston_ops, +}; diff --git a/include/dt-bindings/clock/boston-clock.h b/include/dt-bindings/clock/boston-clock.h new file mode 100644 index 0000000..25f9cd2 --- /dev/null +++ b/include/dt-bindings/clock/boston-clock.h @@ -0,0 +1,13 @@ +/* + * Copyright (C) 2016 Imagination Technologies + * + * SPDX-License-Identifier: GPL-2.0 + */ + +#ifndef __DT_BINDINGS_CLOCK_BOSTON_CLOCK_H__ +#define __DT_BINDINGS_CLOCK_BOSTON_CLOCK_H__ + +#define BOSTON_CLK_SYS 0 +#define BOSTON_CLK_CPU 1 + +#endif /* __DT_BINDINGS_CLOCK_BOSTON_CLOCK_H__ */