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author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-08 11:31:16 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-08 11:31:16 -0700 |
commit | 3f17ea6dea8ba5668873afa54628a91aaa3fb1c0 (patch) | |
tree | afbeb2accd4c2199ddd705ae943995b143a0af02 /drivers/clk/berlin/berlin2-div.c | |
parent | 1860e379875dfe7271c649058aeddffe5afd9d0d (diff) | |
parent | 1a5700bc2d10cd379a795fd2bb377a190af5acd4 (diff) | |
download | linux-3f17ea6dea8ba5668873afa54628a91aaa3fb1c0.tar.bz2 |
Merge branch 'next' (accumulated 3.16 merge window patches) into master
Now that 3.15 is released, this merges the 'next' branch into 'master',
bringing us to the normal situation where my 'master' branch is the
merge window.
* accumulated work in next: (6809 commits)
ufs: sb mutex merge + mutex_destroy
powerpc: update comments for generic idle conversion
cris: update comments for generic idle conversion
idle: remove cpu_idle() forward declarations
nbd: zero from and len fields in NBD_CMD_DISCONNECT.
mm: convert some level-less printks to pr_*
MAINTAINERS: adi-buildroot-devel is moderated
MAINTAINERS: add linux-api for review of API/ABI changes
mm/kmemleak-test.c: use pr_fmt for logging
fs/dlm/debug_fs.c: replace seq_printf by seq_puts
fs/dlm/lockspace.c: convert simple_str to kstr
fs/dlm/config.c: convert simple_str to kstr
mm: mark remap_file_pages() syscall as deprecated
mm: memcontrol: remove unnecessary memcg argument from soft limit functions
mm: memcontrol: clean up memcg zoneinfo lookup
mm/memblock.c: call kmemleak directly from memblock_(alloc|free)
mm/mempool.c: update the kmemleak stack trace for mempool allocations
lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations
mm: introduce kmemleak_update_trace()
mm/kmemleak.c: use %u to print ->checksum
...
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 000000000000..81ff97f8aa0b --- /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); +} |