X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fclk%2Fberlin%2Fberlin2-div.c;fp=kernel%2Fdrivers%2Fclk%2Fberlin%2Fberlin2-div.c;h=81ff97f8aa0bb00d668c80f23ade378bf0905c47;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git diff --git a/kernel/drivers/clk/berlin/berlin2-div.c b/kernel/drivers/clk/berlin/berlin2-div.c new file mode 100644 index 000000000..81ff97f8a --- /dev/null +++ b/kernel/drivers/clk/berlin/berlin2-div.c @@ -0,0 +1,265 @@ +/* + * Copyright (c) 2014 Marvell Technology Group Ltd. + * + * Alexandre Belloni + * Sebastian Hesselbarth + * + * 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 . + */ +#include +#include +#include +#include +#include +#include + +#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 + * (B) input pll bypass mux controlled by + * (C) programmable clock divider controlled by + * (D) constant div-by-3 clock divider + * (E) programmable clock divider bypass controlled by + * (F) constant div-by-3 clock mux controlled by + * (G) clock gate controlled by + * + * 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); +}