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author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-07 20:27:30 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-07 20:27:30 -0700 |
commit | 1a5700bc2d10cd379a795fd2bb377a190af5acd4 (patch) | |
tree | e9f754cbc34020dd23c1d2e3e45fb6890ba7593c /drivers/clk/berlin/berlin2-div.c | |
parent | a68a7509d3af8ee458d32b2416b0c2aaf2a4a7e3 (diff) | |
parent | 3cbcb16095f916f50a5a55066fcc4be06946ce1e (diff) | |
download | op-kernel-dev-1a5700bc2d10cd379a795fd2bb377a190af5acd4.zip op-kernel-dev-1a5700bc2d10cd379a795fd2bb377a190af5acd4.tar.gz |
Merge tag 'clk-for-linus-3.16' of git://git.linaro.org/people/mike.turquette/linux into next
Pull clock framework updates from Mike Turquette:
"The clock framework changes for 3.16 are pretty typical: mostly clock
driver additions and fixes. There are additions to the clock core
code for some of the basic types (e.g. the common divider type has
some fixes and featured added to it).
One minor annoyance is a last-minute dependency that wasn't handled
quite right. Commit ba0fae3b06a6 ("clk: berlin: add core clock driver
for BG2/BG2CD") in this pull request depends on
include/dt-bindings/clock/berlin2.h, which is already in your tree via
the arm-soc pull request. Building for the berlin platform will break
when the clk tree is built on it's own, but merged into your master
branch everything should be fine"
* tag 'clk-for-linus-3.16' of git://git.linaro.org/people/mike.turquette/linux: (75 commits)
mmc: sunxi: Add driver for SD/MMC hosts found on Allwinner sunxi SoCs
clk: export __clk_round_rate for providers
clk: versatile: free icst on error return
clk: qcom: Return error pointers for unimplemented clocks
clk: qcom: Support msm8974pro global clock control hardware
clk: qcom: Properly support display clocks on msm8974
clk: qcom: Support display RCG clocks
clk: qcom: Return highest rate when round_rate() exceeds plan
clk: qcom: Fix mmcc-8974's PLL configurations
clk: qcom: Fix clk_rcg2_is_enabled() check
clk: berlin: add core clock driver for BG2Q
clk: berlin: add core clock driver for BG2/BG2CD
clk: berlin: add driver for BG2x complex divider cells
clk: berlin: add driver for BG2x simple PLLs
clk: berlin: add driver for BG2x audio/video PLL
clk: st: Terminate of match table
clk/exynos4: Fix compilation warning
ARM: shmobile: r8a7779: Add clock index macros for DT sources
clk: divider: Fix overflow in clk_divider_bestdiv
clk: u300: Terminate of match table
...
Diffstat (limited to 'drivers/clk/berlin/berlin2-div.c')
-rw-r--r-- | drivers/clk/berlin/berlin2-div.c | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/drivers/clk/berlin/berlin2-div.c b/drivers/clk/berlin/berlin2-div.c new file mode 100644 index 0000000..81ff97f --- /dev/null +++ b/drivers/clk/berlin/berlin2-div.c @@ -0,0 +1,265 @@ +/* + * Copyright (c) 2014 Marvell Technology Group Ltd. + * + * Alexandre Belloni <alexandre.belloni@free-electrons.com> + * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ +#include <linux/bitops.h> +#include <linux/clk-provider.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +#include "berlin2-div.h" + +/* + * Clock dividers in Berlin2 SoCs comprise a complex cell to select + * input pll and divider. The virtual structure as it is used in Marvell + * BSP code can be seen as: + * + * +---+ + * pll0 --------------->| 0 | +---+ + * +---+ |(B)|--+--------------->| 0 | +---+ + * pll1.0 -->| 0 | +-->| 1 | | +--------+ |(E)|----->| 0 | +---+ + * pll1.1 -->| 1 | | +---+ +-->|(C) 1:M |-->| 1 | |(F)|-->|(G)|-> + * ... -->|(A)|--+ | +--------+ +---+ +-->| 1 | +---+ + * ... -->| | +-->|(D) 1:3 |----------+ +---+ + * pll1.N -->| N | +--------- + * +---+ + * + * (A) input pll clock mux controlled by <PllSelect[1:n]> + * (B) input pll bypass mux controlled by <PllSwitch> + * (C) programmable clock divider controlled by <Select[1:n]> + * (D) constant div-by-3 clock divider + * (E) programmable clock divider bypass controlled by <Switch> + * (F) constant div-by-3 clock mux controlled by <D3Switch> + * (G) clock gate controlled by <Enable> + * + * For whatever reason, above control signals come in two flavors: + * - single register dividers with all bits in one register + * - shared register dividers with bits spread over multiple registers + * (including signals for the same cell spread over consecutive registers) + * + * Also, clock gate and pll mux is not available on every div cell, so + * we have to deal with those, too. We reuse common clock composite driver + * for it. + */ + +#define PLL_SELECT_MASK 0x7 +#define DIV_SELECT_MASK 0x7 + +struct berlin2_div { + struct clk_hw hw; + void __iomem *base; + struct berlin2_div_map map; + spinlock_t *lock; +}; + +#define to_berlin2_div(hw) container_of(hw, struct berlin2_div, hw) + +static u8 clk_div[] = { 1, 2, 4, 6, 8, 12, 1, 1 }; + +static int berlin2_div_is_enabled(struct clk_hw *hw) +{ + struct berlin2_div *div = to_berlin2_div(hw); + struct berlin2_div_map *map = &div->map; + u32 reg; + + if (div->lock) + spin_lock(div->lock); + + reg = readl_relaxed(div->base + map->gate_offs); + reg >>= map->gate_shift; + + if (div->lock) + spin_unlock(div->lock); + + return (reg & 0x1); +} + +static int berlin2_div_enable(struct clk_hw *hw) +{ + struct berlin2_div *div = to_berlin2_div(hw); + struct berlin2_div_map *map = &div->map; + u32 reg; + + if (div->lock) + spin_lock(div->lock); + + reg = readl_relaxed(div->base + map->gate_offs); + reg |= BIT(map->gate_shift); + writel_relaxed(reg, div->base + map->gate_offs); + + if (div->lock) + spin_unlock(div->lock); + + return 0; +} + +static void berlin2_div_disable(struct clk_hw *hw) +{ + struct berlin2_div *div = to_berlin2_div(hw); + struct berlin2_div_map *map = &div->map; + u32 reg; + + if (div->lock) + spin_lock(div->lock); + + reg = readl_relaxed(div->base + map->gate_offs); + reg &= ~BIT(map->gate_shift); + writel_relaxed(reg, div->base + map->gate_offs); + + if (div->lock) + spin_unlock(div->lock); +} + +static int berlin2_div_set_parent(struct clk_hw *hw, u8 index) +{ + struct berlin2_div *div = to_berlin2_div(hw); + struct berlin2_div_map *map = &div->map; + u32 reg; + + if (div->lock) + spin_lock(div->lock); + + /* index == 0 is PLL_SWITCH */ + reg = readl_relaxed(div->base + map->pll_switch_offs); + if (index == 0) + reg &= ~BIT(map->pll_switch_shift); + else + reg |= BIT(map->pll_switch_shift); + writel_relaxed(reg, div->base + map->pll_switch_offs); + + /* index > 0 is PLL_SELECT */ + if (index > 0) { + reg = readl_relaxed(div->base + map->pll_select_offs); + reg &= ~(PLL_SELECT_MASK << map->pll_select_shift); + reg |= (index - 1) << map->pll_select_shift; + writel_relaxed(reg, div->base + map->pll_select_offs); + } + + if (div->lock) + spin_unlock(div->lock); + + return 0; +} + +static u8 berlin2_div_get_parent(struct clk_hw *hw) +{ + struct berlin2_div *div = to_berlin2_div(hw); + struct berlin2_div_map *map = &div->map; + u32 reg; + u8 index = 0; + + if (div->lock) + spin_lock(div->lock); + + /* PLL_SWITCH == 0 is index 0 */ + reg = readl_relaxed(div->base + map->pll_switch_offs); + reg &= BIT(map->pll_switch_shift); + if (reg) { + reg = readl_relaxed(div->base + map->pll_select_offs); + reg >>= map->pll_select_shift; + reg &= PLL_SELECT_MASK; + index = 1 + reg; + } + + if (div->lock) + spin_unlock(div->lock); + + return index; +} + +static unsigned long berlin2_div_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct berlin2_div *div = to_berlin2_div(hw); + struct berlin2_div_map *map = &div->map; + u32 divsw, div3sw, divider = 1; + + if (div->lock) + spin_lock(div->lock); + + divsw = readl_relaxed(div->base + map->div_switch_offs) & + (1 << map->div_switch_shift); + div3sw = readl_relaxed(div->base + map->div3_switch_offs) & + (1 << map->div3_switch_shift); + + /* constant divide-by-3 (dominant) */ + if (div3sw != 0) { + divider = 3; + /* divider can be bypassed with DIV_SWITCH == 0 */ + } else if (divsw == 0) { + divider = 1; + /* clock divider determined by DIV_SELECT */ + } else { + u32 reg; + reg = readl_relaxed(div->base + map->div_select_offs); + reg >>= map->div_select_shift; + reg &= DIV_SELECT_MASK; + divider = clk_div[reg]; + } + + if (div->lock) + spin_unlock(div->lock); + + return parent_rate / divider; +} + +static const struct clk_ops berlin2_div_rate_ops = { + .recalc_rate = berlin2_div_recalc_rate, +}; + +static const struct clk_ops berlin2_div_gate_ops = { + .is_enabled = berlin2_div_is_enabled, + .enable = berlin2_div_enable, + .disable = berlin2_div_disable, +}; + +static const struct clk_ops berlin2_div_mux_ops = { + .set_parent = berlin2_div_set_parent, + .get_parent = berlin2_div_get_parent, +}; + +struct clk * __init +berlin2_div_register(const struct berlin2_div_map *map, + void __iomem *base, const char *name, u8 div_flags, + const char **parent_names, int num_parents, + unsigned long flags, spinlock_t *lock) +{ + const struct clk_ops *mux_ops = &berlin2_div_mux_ops; + const struct clk_ops *rate_ops = &berlin2_div_rate_ops; + const struct clk_ops *gate_ops = &berlin2_div_gate_ops; + struct berlin2_div *div; + + div = kzalloc(sizeof(*div), GFP_KERNEL); + if (!div) + return ERR_PTR(-ENOMEM); + + /* copy div_map to allow __initconst */ + memcpy(&div->map, map, sizeof(*map)); + div->base = base; + div->lock = lock; + + if ((div_flags & BERLIN2_DIV_HAS_GATE) == 0) + gate_ops = NULL; + if ((div_flags & BERLIN2_DIV_HAS_MUX) == 0) + mux_ops = NULL; + + return clk_register_composite(NULL, name, parent_names, num_parents, + &div->hw, mux_ops, &div->hw, rate_ops, + &div->hw, gate_ops, flags); +} |