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Diffstat (limited to '')
-rw-r--r-- | drivers/clk/at91/clk-plldiv.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/drivers/clk/at91/clk-plldiv.c b/drivers/clk/at91/clk-plldiv.c new file mode 100644 index 000000000..b4afaf22f --- /dev/null +++ b/drivers/clk/at91/clk-plldiv.c @@ -0,0 +1,133 @@ +/* + * Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.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. + * + */ + +#include <linux/clk-provider.h> +#include <linux/clkdev.h> +#include <linux/clk/at91_pmc.h> +#include <linux/of.h> +#include <linux/mfd/syscon.h> +#include <linux/regmap.h> + +#include "pmc.h" + +#define to_clk_plldiv(hw) container_of(hw, struct clk_plldiv, hw) + +struct clk_plldiv { + struct clk_hw hw; + struct regmap *regmap; +}; + +static unsigned long clk_plldiv_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_plldiv *plldiv = to_clk_plldiv(hw); + unsigned int mckr; + + regmap_read(plldiv->regmap, AT91_PMC_MCKR, &mckr); + + if (mckr & AT91_PMC_PLLADIV2) + return parent_rate / 2; + + return parent_rate; +} + +static long clk_plldiv_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + unsigned long div; + + if (rate > *parent_rate) + return *parent_rate; + div = *parent_rate / 2; + if (rate < div) + return div; + + if (rate - div < *parent_rate - rate) + return div; + + return *parent_rate; +} + +static int clk_plldiv_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clk_plldiv *plldiv = to_clk_plldiv(hw); + + if ((parent_rate != rate) && (parent_rate / 2 != rate)) + return -EINVAL; + + regmap_update_bits(plldiv->regmap, AT91_PMC_MCKR, AT91_PMC_PLLADIV2, + parent_rate != rate ? AT91_PMC_PLLADIV2 : 0); + + return 0; +} + +static const struct clk_ops plldiv_ops = { + .recalc_rate = clk_plldiv_recalc_rate, + .round_rate = clk_plldiv_round_rate, + .set_rate = clk_plldiv_set_rate, +}; + +static struct clk_hw * __init +at91_clk_register_plldiv(struct regmap *regmap, const char *name, + const char *parent_name) +{ + struct clk_plldiv *plldiv; + struct clk_hw *hw; + struct clk_init_data init; + int ret; + + plldiv = kzalloc(sizeof(*plldiv), GFP_KERNEL); + if (!plldiv) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &plldiv_ops; + init.parent_names = parent_name ? &parent_name : NULL; + init.num_parents = parent_name ? 1 : 0; + init.flags = CLK_SET_RATE_GATE; + + plldiv->hw.init = &init; + plldiv->regmap = regmap; + + hw = &plldiv->hw; + ret = clk_hw_register(NULL, &plldiv->hw); + if (ret) { + kfree(plldiv); + hw = ERR_PTR(ret); + } + + return hw; +} + +static void __init +of_at91sam9x5_clk_plldiv_setup(struct device_node *np) +{ + struct clk_hw *hw; + const char *parent_name; + const char *name = np->name; + struct regmap *regmap; + + parent_name = of_clk_get_parent_name(np, 0); + + of_property_read_string(np, "clock-output-names", &name); + + regmap = syscon_node_to_regmap(of_get_parent(np)); + if (IS_ERR(regmap)) + return; + + hw = at91_clk_register_plldiv(regmap, name, parent_name); + if (IS_ERR(hw)) + return; + + of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw); +} +CLK_OF_DECLARE(at91sam9x5_clk_plldiv, "atmel,at91sam9x5-clk-plldiv", + of_at91sam9x5_clk_plldiv_setup); |