diff options
Diffstat (limited to 'drivers/clk/uniphier/clk-uniphier-cpugear.c')
| -rw-r--r-- | drivers/clk/uniphier/clk-uniphier-cpugear.c | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/drivers/clk/uniphier/clk-uniphier-cpugear.c b/drivers/clk/uniphier/clk-uniphier-cpugear.c new file mode 100644 index 000000000..5d2d42b7e --- /dev/null +++ b/drivers/clk/uniphier/clk-uniphier-cpugear.c @@ -0,0 +1,114 @@ +/* + * Copyright (C) 2016 Socionext Inc. + * Author: Masahiro Yamada <yamada.masahiro@socionext.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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/clk-provider.h> +#include <linux/device.h> +#include <linux/regmap.h> + +#include "clk-uniphier.h" + +#define UNIPHIER_CLK_CPUGEAR_STAT 0 /* status */ +#define UNIPHIER_CLK_CPUGEAR_SET 4 /* set */ +#define UNIPHIER_CLK_CPUGEAR_UPD 8 /* update */ +#define UNIPHIER_CLK_CPUGEAR_UPD_BIT BIT(0) + +struct uniphier_clk_cpugear { + struct clk_hw hw; + struct regmap *regmap; + unsigned int regbase; + unsigned int mask; +}; + +#define to_uniphier_clk_cpugear(_hw) \ + container_of(_hw, struct uniphier_clk_cpugear, hw) + +static int uniphier_clk_cpugear_set_parent(struct clk_hw *hw, u8 index) +{ + struct uniphier_clk_cpugear *gear = to_uniphier_clk_cpugear(hw); + int ret; + unsigned int val; + + ret = regmap_write_bits(gear->regmap, + gear->regbase + UNIPHIER_CLK_CPUGEAR_SET, + gear->mask, index); + if (ret) + return ret; + + ret = regmap_write_bits(gear->regmap, + gear->regbase + UNIPHIER_CLK_CPUGEAR_UPD, + UNIPHIER_CLK_CPUGEAR_UPD_BIT, + UNIPHIER_CLK_CPUGEAR_UPD_BIT); + if (ret) + return ret; + + return regmap_read_poll_timeout(gear->regmap, + gear->regbase + UNIPHIER_CLK_CPUGEAR_UPD, + val, !(val & UNIPHIER_CLK_CPUGEAR_UPD_BIT), + 0, 1); +} + +static u8 uniphier_clk_cpugear_get_parent(struct clk_hw *hw) +{ + struct uniphier_clk_cpugear *gear = to_uniphier_clk_cpugear(hw); + int num_parents = clk_hw_get_num_parents(hw); + int ret; + unsigned int val; + + ret = regmap_read(gear->regmap, + gear->regbase + UNIPHIER_CLK_CPUGEAR_STAT, &val); + if (ret) + return ret; + + val &= gear->mask; + + return val < num_parents ? val : -EINVAL; +} + +static const struct clk_ops uniphier_clk_cpugear_ops = { + .determine_rate = __clk_mux_determine_rate, + .set_parent = uniphier_clk_cpugear_set_parent, + .get_parent = uniphier_clk_cpugear_get_parent, +}; + +struct clk_hw *uniphier_clk_register_cpugear(struct device *dev, + struct regmap *regmap, + const char *name, + const struct uniphier_clk_cpugear_data *data) +{ + struct uniphier_clk_cpugear *gear; + struct clk_init_data init; + int ret; + + gear = devm_kzalloc(dev, sizeof(*gear), GFP_KERNEL); + if (!gear) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &uniphier_clk_cpugear_ops; + init.flags = CLK_SET_RATE_PARENT; + init.parent_names = data->parent_names; + init.num_parents = data->num_parents, + + gear->regmap = regmap; + gear->regbase = data->regbase; + gear->mask = data->mask; + gear->hw.init = &init; + + ret = devm_clk_hw_register(dev, &gear->hw); + if (ret) + return ERR_PTR(ret); + + return &gear->hw; +} |