Hi Paul,
On 27 July 2016 at 08:26, Paul Burton <paul.bur...@imgtec.com> wrote:
> 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.bur...@imgtec.com>
>
> ---
>
> Changes in v2:
> - New patch
>
> drivers/clk/Kconfig | 8 +++
> drivers/clk/Makefile | 1 +
> drivers/clk/clk_boston.c | 96
> ++++++++++++++++++++++++++++++++
> include/dt-bindings/clock/boston-clock.h | 13 +++++
> 4 files changed, 118 insertions(+)
> create mode 100644 drivers/clk/clk_boston.c
> create mode 100644 include/dt-bindings/clock/boston-clock.h
Reviewed-by: Simon Glass <s...@chromium.org>
>
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index 6eee8eb..85eea0d 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/uniphier/Kconfig"
> source "drivers/clk/exynos/Kconfig"
>
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index f7a8891..9d14122 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -13,3 +13,4 @@ obj-$(CONFIG_SANDBOX) += clk_sandbox_test.o
> obj-$(CONFIG_MACH_PIC32) += clk_pic32.o
> obj-$(CONFIG_CLK_UNIPHIER) += uniphier/
> obj-$(CONFIG_CLK_EXYNOS) += exynos/
> +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..dbbb05b
> --- /dev/null
> +++ b/drivers/clk/clk_boston.c
> @@ -0,0 +1,96 @@
> +/*
> + * 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 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;
> +
> +#define EXT(field) ((mmcmdiv & field) >> (ffs(field) - 1))
Why not use a function for this?
> +
> + in_rate = EXT(BOSTON_PLAT_MMCMDIV_INPUT);
> + mul = EXT(BOSTON_PLAT_MMCMDIV_MUL);
> +
> + switch (clk->id) {
> + case BOSTON_CLK_SYS:
> + div = EXT(BOSTON_PLAT_MMCMDIV_CLK0DIV);
> + break;
> + case BOSTON_CLK_CPU:
> + div = EXT(BOSTON_PLAT_MMCMDIV_CLK1DIV);
> + break;
> + default:
> + return 0;
> + }
> +
> +#undef EXT
> +
> + 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);
Note that this is slow. But perhaps it doesn't matter.
> + 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__ */
> --
> 2.9.0
>
Regards,
Simon
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