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author | Maxime Ripard <maxime.ripard@free-electrons.com> | 2016-06-29 21:05:32 +0200 |
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committer | Michael Turquette <mturquette@baylibre.com> | 2016-07-08 18:05:03 -0700 |
commit | df6561e60244c0283340286664b0baf67e846599 (patch) | |
tree | 856a3f8de7b763362c765bcb36ab80f9ce646e2a /drivers/clk | |
parent | 6174a1e24b0d13f85f64ff570e9d4efc6b0d6287 (diff) | |
download | linux-stable-df6561e60244c0283340286664b0baf67e846599.tar.gz linux-stable-df6561e60244c0283340286664b0baf67e846599.tar.bz2 linux-stable-df6561e60244c0283340286664b0baf67e846599.zip |
clk: sunxi-ng: Add N-K-M Factor clock
Introduce support for clocks that multiply and divide using two linear
multipliers and one linear divider.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20160629190535.11855-12-maxime.ripard@free-electrons.com
Diffstat (limited to 'drivers/clk')
-rw-r--r-- | drivers/clk/sunxi-ng/Kconfig | 5 | ||||
-rw-r--r-- | drivers/clk/sunxi-ng/Makefile | 1 | ||||
-rw-r--r-- | drivers/clk/sunxi-ng/ccu_nkm.c | 153 | ||||
-rw-r--r-- | drivers/clk/sunxi-ng/ccu_nkm.h | 68 |
4 files changed, 227 insertions, 0 deletions
diff --git a/drivers/clk/sunxi-ng/Kconfig b/drivers/clk/sunxi-ng/Kconfig index d8a5da270778..4c571b86bfd1 100644 --- a/drivers/clk/sunxi-ng/Kconfig +++ b/drivers/clk/sunxi-ng/Kconfig @@ -28,6 +28,11 @@ config SUNXI_CCU_NK bool select SUNXI_CCU_GATE +config SUNXI_CCU_NKM + bool + select RATIONAL + select SUNXI_CCU_GATE + config SUNXI_CCU_NM bool select RATIONAL diff --git a/drivers/clk/sunxi-ng/Makefile b/drivers/clk/sunxi-ng/Makefile index 7d2cd2a47a39..2d6fdca0d3cc 100644 --- a/drivers/clk/sunxi-ng/Makefile +++ b/drivers/clk/sunxi-ng/Makefile @@ -11,5 +11,6 @@ obj-$(CONFIG_SUNXI_CCU_PHASE) += ccu_phase.o # Multi-factor clocks obj-$(CONFIG_SUNXI_CCU_NK) += ccu_nk.o +obj-$(CONFIG_SUNXI_CCU_NKM) += ccu_nkm.o obj-$(CONFIG_SUNXI_CCU_NM) += ccu_nm.o obj-$(CONFIG_SUNXI_CCU_MP) += ccu_mp.o diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c new file mode 100644 index 000000000000..2071822b1e9c --- /dev/null +++ b/drivers/clk/sunxi-ng/ccu_nkm.c @@ -0,0 +1,153 @@ +/* + * 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_gate.h" +#include "ccu_nkm.h" + +struct _ccu_nkm { + unsigned long n, max_n; + unsigned long k, max_k; + unsigned long m, max_m; +}; + +static void ccu_nkm_find_best(unsigned long parent, unsigned long rate, + struct _ccu_nkm *nkm) +{ + unsigned long best_rate = 0; + unsigned long best_n = 0, best_k = 0, best_m = 0; + unsigned long _n, _k, _m; + + for (_k = 1; _k <= nkm->max_k; _k++) { + unsigned long tmp_rate; + + rational_best_approximation(rate / _k, parent, + nkm->max_n, nkm->max_m, &_n, &_m); + + tmp_rate = parent * _n * _k / _m; + + if (tmp_rate > rate) + continue; + + if ((rate - tmp_rate) < (rate - best_rate)) { + best_rate = tmp_rate; + best_n = _n; + best_k = _k; + best_m = _m; + } + } + + nkm->n = best_n; + nkm->k = best_k; + nkm->m = best_m; +} + +static void ccu_nkm_disable(struct clk_hw *hw) +{ + struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); + + return ccu_gate_helper_disable(&nkm->common, nkm->enable); +} + +static int ccu_nkm_enable(struct clk_hw *hw) +{ + struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); + + return ccu_gate_helper_enable(&nkm->common, nkm->enable); +} + +static int ccu_nkm_is_enabled(struct clk_hw *hw) +{ + struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); + + return ccu_gate_helper_is_enabled(&nkm->common, nkm->enable); +} + +static unsigned long ccu_nkm_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); + unsigned long n, m, k; + u32 reg; + + reg = readl(nkm->common.base + nkm->common.reg); + + n = reg >> nkm->n.shift; + n &= (1 << nkm->n.width) - 1; + + k = reg >> nkm->k.shift; + k &= (1 << nkm->k.width) - 1; + + m = reg >> nkm->m.shift; + m &= (1 << nkm->m.width) - 1; + + return parent_rate * (n + 1) * (k + 1) / (m + 1); +} + +static long ccu_nkm_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); + struct _ccu_nkm _nkm; + + _nkm.max_n = 1 << nkm->n.width; + _nkm.max_k = 1 << nkm->k.width; + _nkm.max_m = 1 << nkm->m.width; + + ccu_nkm_find_best(*parent_rate, rate, &_nkm); + + return *parent_rate * _nkm.n * _nkm.k / _nkm.m; +} + +static int ccu_nkm_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); + struct _ccu_nkm _nkm; + unsigned long flags; + u32 reg; + + _nkm.max_n = 1 << nkm->n.width; + _nkm.max_k = 1 << nkm->k.width; + _nkm.max_m = 1 << nkm->m.width; + + ccu_nkm_find_best(parent_rate, rate, &_nkm); + + spin_lock_irqsave(nkm->common.lock, flags); + + reg = readl(nkm->common.base + nkm->common.reg); + reg &= ~GENMASK(nkm->n.width + nkm->n.shift - 1, nkm->n.shift); + reg &= ~GENMASK(nkm->k.width + nkm->k.shift - 1, nkm->k.shift); + reg &= ~GENMASK(nkm->m.width + nkm->m.shift - 1, nkm->m.shift); + + reg |= (_nkm.n - 1) << nkm->n.shift; + reg |= (_nkm.k - 1) << nkm->k.shift; + reg |= (_nkm.m - 1) << nkm->m.shift; + + writel(reg, nkm->common.base + nkm->common.reg); + + spin_unlock_irqrestore(nkm->common.lock, flags); + + ccu_helper_wait_for_lock(&nkm->common, nkm->lock); + + return 0; +} + +const struct clk_ops ccu_nkm_ops = { + .disable = ccu_nkm_disable, + .enable = ccu_nkm_enable, + .is_enabled = ccu_nkm_is_enabled, + + .recalc_rate = ccu_nkm_recalc_rate, + .round_rate = ccu_nkm_round_rate, + .set_rate = ccu_nkm_set_rate, +}; diff --git a/drivers/clk/sunxi-ng/ccu_nkm.h b/drivers/clk/sunxi-ng/ccu_nkm.h new file mode 100644 index 000000000000..1936ac1c6b37 --- /dev/null +++ b/drivers/clk/sunxi-ng/ccu_nkm.h @@ -0,0 +1,68 @@ +/* + * Copyright (c) 2016 Maxime Ripard. All rights reserved. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * 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. + */ + +#ifndef _CCU_NKM_H_ +#define _CCU_NKM_H_ + +#include <linux/clk-provider.h> + +#include "ccu_common.h" +#include "ccu_div.h" +#include "ccu_mult.h" + +/* + * struct ccu_nkm - Definition of an N-K-M clock + * + * Clocks based on the formula parent * N * K / M + */ +struct ccu_nkm { + u32 enable; + u32 lock; + + struct _ccu_mult n; + struct _ccu_mult k; + struct _ccu_div m; + + struct ccu_common common; +}; + +#define SUNXI_CCU_NKM_WITH_GATE_LOCK(_struct, _name, _parent, _reg, \ + _nshift, _nwidth, \ + _kshift, _kwidth, \ + _mshift, _mwidth, \ + _gate, _lock, _flags) \ + struct ccu_nkm _struct = { \ + .enable = _gate, \ + .lock = _lock, \ + .k = _SUNXI_CCU_MULT(_kshift, _kwidth), \ + .n = _SUNXI_CCU_MULT(_nshift, _nwidth), \ + .m = _SUNXI_CCU_DIV(_mshift, _mwidth), \ + .common = { \ + .reg = _reg, \ + .hw.init = CLK_HW_INIT(_name, \ + _parent, \ + &ccu_nkm_ops, \ + _flags), \ + }, \ + } + +static inline struct ccu_nkm *hw_to_ccu_nkm(struct clk_hw *hw) +{ + struct ccu_common *common = hw_to_ccu_common(hw); + + return container_of(common, struct ccu_nkm, common); +} + +extern const struct clk_ops ccu_nkm_ops; + +#endif /* _CCU_NKM_H_ */ |