diff options
Diffstat (limited to 'drivers/clk/clk_boston.c')
-rw-r--r-- | drivers/clk/clk_boston.c | 97 |
1 files changed, 97 insertions, 0 deletions
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, +}; |