diff options
Diffstat (limited to 'drivers/clk/sunxi-ng/ccu_nm.c')
-rw-r--r-- | drivers/clk/sunxi-ng/ccu_nm.c | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/drivers/clk/sunxi-ng/ccu_nm.c b/drivers/clk/sunxi-ng/ccu_nm.c new file mode 100644 index 0000000..e35ddd8 --- /dev/null +++ b/drivers/clk/sunxi-ng/ccu_nm.c @@ -0,0 +1,114 @@ +/* + * Copyright (C) 2016 Maxime Ripard + * Maxime Ripard <maxime.ripard@free-electrons.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/rational.h> + +#include "ccu_frac.h" +#include "ccu_gate.h" +#include "ccu_nm.h" + +static void ccu_nm_disable(struct clk_hw *hw) +{ + struct ccu_nm *nm = hw_to_ccu_nm(hw); + + return ccu_gate_helper_disable(&nm->common, nm->enable); +} + +static int ccu_nm_enable(struct clk_hw *hw) +{ + struct ccu_nm *nm = hw_to_ccu_nm(hw); + + return ccu_gate_helper_enable(&nm->common, nm->enable); +} + +static int ccu_nm_is_enabled(struct clk_hw *hw) +{ + struct ccu_nm *nm = hw_to_ccu_nm(hw); + + return ccu_gate_helper_is_enabled(&nm->common, nm->enable); +} + +static unsigned long ccu_nm_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct ccu_nm *nm = hw_to_ccu_nm(hw); + unsigned long n, m; + u32 reg; + + if (ccu_frac_helper_is_enabled(&nm->common, &nm->frac)) + return ccu_frac_helper_read_rate(&nm->common, &nm->frac); + + reg = readl(nm->common.base + nm->common.reg); + + n = reg >> nm->n.shift; + n &= (1 << nm->n.width) - 1; + + m = reg >> nm->m.shift; + m &= (1 << nm->m.width) - 1; + + return parent_rate * (n + 1) / (m + 1); +} + +static long ccu_nm_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct ccu_nm *nm = hw_to_ccu_nm(hw); + unsigned long n, m; + + rational_best_approximation(rate, *parent_rate, + 1 << nm->n.width, 1 << nm->m.width, + &n, &m); + + return *parent_rate * n / m; +} + +static int ccu_nm_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct ccu_nm *nm = hw_to_ccu_nm(hw); + unsigned long flags; + unsigned long n, m; + u32 reg; + + if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate)) + return ccu_frac_helper_set_rate(&nm->common, &nm->frac, rate); + else + ccu_frac_helper_disable(&nm->common, &nm->frac); + + rational_best_approximation(rate, parent_rate, + 1 << nm->n.width, 1 << nm->m.width, + &n, &m); + + spin_lock_irqsave(nm->common.lock, flags); + + reg = readl(nm->common.base + nm->common.reg); + reg &= ~GENMASK(nm->n.width + nm->n.shift - 1, nm->n.shift); + reg &= ~GENMASK(nm->m.width + nm->m.shift - 1, nm->m.shift); + + writel(reg | ((m - 1) << nm->m.shift) | ((n - 1) << nm->n.shift), + nm->common.base + nm->common.reg); + + spin_unlock_irqrestore(nm->common.lock, flags); + + ccu_helper_wait_for_lock(&nm->common, nm->lock); + + return 0; +} + +const struct clk_ops ccu_nm_ops = { + .disable = ccu_nm_disable, + .enable = ccu_nm_enable, + .is_enabled = ccu_nm_is_enabled, + + .recalc_rate = ccu_nm_recalc_rate, + .round_rate = ccu_nm_round_rate, + .set_rate = ccu_nm_set_rate, +}; |