diff options
Diffstat (limited to 'drivers/clk/at91/clk-plldiv.c')
-rw-r--r-- | drivers/clk/at91/clk-plldiv.c | 103 |
1 files changed, 103 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..ba3a1839a --- /dev/null +++ b/drivers/clk/at91/clk-plldiv.c @@ -0,0 +1,103 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com> + */ + +#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, +}; + +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; +} |