diff options
author | Paul Burton <paul.burton@imgtec.com> | 2017-06-17 13:52:47 -0700 |
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committer | Ralf Baechle <ralf@linux-mips.org> | 2017-07-11 14:13:06 +0200 |
commit | 6b0fd6c1a22da18a00f8ce12014d55ce0a316651 (patch) | |
tree | 2ad0be57c5b50bf4126943a9d842daf06b5db0f9 /drivers/clk/imgtec | |
parent | 7461279bba4a62d192eda6dd10de68ac0543bfcd (diff) | |
download | linux-6b0fd6c1a22da18a00f8ce12014d55ce0a316651.tar.bz2 |
clk: boston: Add a driver for MIPS Boston board clocks
Add a driver for the clocks provided by the MIPS Boston board from
Imagination Technologies. 2 clocks are provided - the system clock & the
CPU clock - and each is a simple fixed rate clock whose frequency can be
determined by reading a register provided by the board.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: linux-clk@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16483/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'drivers/clk/imgtec')
-rw-r--r-- | drivers/clk/imgtec/Kconfig | 9 | ||||
-rw-r--r-- | drivers/clk/imgtec/Makefile | 1 | ||||
-rw-r--r-- | drivers/clk/imgtec/clk-boston.c | 103 |
3 files changed, 113 insertions, 0 deletions
diff --git a/drivers/clk/imgtec/Kconfig b/drivers/clk/imgtec/Kconfig new file mode 100644 index 000000000000..f6dcb748e9c4 --- /dev/null +++ b/drivers/clk/imgtec/Kconfig @@ -0,0 +1,9 @@ +config COMMON_CLK_BOSTON + bool "Clock driver for MIPS Boston boards" + depends on MIPS || COMPILE_TEST + select MFD_SYSCON + ---help--- + Enable this to support the system & CPU clocks on the MIPS Boston + development board from Imagination Technologies. These are simple + fixed rate clocks whose rate is determined by reading a platform + provided register. diff --git a/drivers/clk/imgtec/Makefile b/drivers/clk/imgtec/Makefile new file mode 100644 index 000000000000..ac779b8c22f2 --- /dev/null +++ b/drivers/clk/imgtec/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_COMMON_CLK_BOSTON) += clk-boston.o diff --git a/drivers/clk/imgtec/clk-boston.c b/drivers/clk/imgtec/clk-boston.c new file mode 100644 index 000000000000..f18f10351785 --- /dev/null +++ b/drivers/clk/imgtec/clk-boston.c @@ -0,0 +1,103 @@ +/* + * Copyright (C) 2016-2017 Imagination Technologies + * Author: Paul Burton <paul.burton@imgtec.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#define pr_fmt(fmt) "clk-boston: " fmt + +#include <linux/clk-provider.h> +#include <linux/kernel.h> +#include <linux/of.h> +#include <linux/regmap.h> +#include <linux/slab.h> +#include <linux/mfd/syscon.h> + +#include <dt-bindings/clock/boston-clock.h> + +#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) + +#define BOSTON_CLK_COUNT 3 + +static u32 ext_field(u32 val, u32 mask) +{ + return (val & mask) >> (ffs(mask) - 1); +} + +static void __init clk_boston_setup(struct device_node *np) +{ + unsigned long in_freq, cpu_freq, sys_freq; + uint mmcmdiv, mul, cpu_div, sys_div; + struct clk_hw_onecell_data *onecell; + struct regmap *regmap; + struct clk_hw *hw; + int err; + + regmap = syscon_node_to_regmap(np->parent); + if (IS_ERR(regmap)) { + pr_err("failed to find regmap\n"); + return; + } + + err = regmap_read(regmap, BOSTON_PLAT_MMCMDIV, &mmcmdiv); + if (err) { + pr_err("failed to read mmcm_div register: %d\n", err); + return; + } + + in_freq = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_INPUT) * 1000000; + mul = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_MUL); + + sys_div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK0DIV); + sys_freq = mult_frac(in_freq, mul, sys_div); + + cpu_div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK1DIV); + cpu_freq = mult_frac(in_freq, mul, cpu_div); + + onecell = kzalloc(sizeof(*onecell) + + (BOSTON_CLK_COUNT * sizeof(struct clk_hw *)), + GFP_KERNEL); + if (!onecell) + return; + + onecell->num = BOSTON_CLK_COUNT; + + hw = clk_hw_register_fixed_rate(NULL, "input", NULL, 0, in_freq); + if (IS_ERR(hw)) { + pr_err("failed to register input clock: %ld\n", PTR_ERR(hw)); + return; + } + onecell->hws[BOSTON_CLK_INPUT] = hw; + + hw = clk_hw_register_fixed_rate(NULL, "sys", "input", 0, sys_freq); + if (IS_ERR(hw)) { + pr_err("failed to register sys clock: %ld\n", PTR_ERR(hw)); + return; + } + onecell->hws[BOSTON_CLK_SYS] = hw; + + hw = clk_hw_register_fixed_rate(NULL, "cpu", "input", 0, cpu_freq); + if (IS_ERR(hw)) { + pr_err("failed to register cpu clock: %ld\n", PTR_ERR(hw)); + return; + } + onecell->hws[BOSTON_CLK_CPU] = hw; + + err = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, onecell); + if (err) + pr_err("failed to add DT provider: %d\n", err); +} + +/* + * Use CLK_OF_DECLARE so that this driver is probed early enough to provide the + * CPU frequency for use with the GIC or cop0 counters/timers. + */ +CLK_OF_DECLARE(clk_boston, "img,boston-clock", clk_boston_setup); |