diff options
Diffstat (limited to 'drivers/clk/imgtec/clk-boston.c')
| -rw-r--r-- | drivers/clk/imgtec/clk-boston.c | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/drivers/clk/imgtec/clk-boston.c b/drivers/clk/imgtec/clk-boston.c new file mode 100644 index 000000000..dddda4512 --- /dev/null +++ b/drivers/clk/imgtec/clk-boston.c @@ -0,0 +1,116 @@ +/* + * Copyright (C) 2016-2017 Imagination Technologies + * Author: Paul Burton <paul.burton@mips.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)); + goto fail_input; + } + 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)); + goto fail_sys; + } + 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)); + goto fail_cpu; + } + 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); + goto fail_clk_add; + } + + return; + +fail_clk_add: + clk_hw_unregister_fixed_rate(onecell->hws[BOSTON_CLK_CPU]); +fail_cpu: + clk_hw_unregister_fixed_rate(onecell->hws[BOSTON_CLK_SYS]); +fail_sys: + clk_hw_unregister_fixed_rate(onecell->hws[BOSTON_CLK_INPUT]); +fail_input: + kfree(onecell); +} + +/* + * 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); |