From: Alexandre Belloni <alexandre.bell...@free-electrons.com> This is a driver for the complex divider cells found on Marvell Berlin2 SoCs. The cells come in two flavors: single register cells and shared register cells. The single register cells are registered by using a DT node, while the shared ones will be taken care of in a SoC-specific core clock driver.
Signed-off-by: Alexandre Belloni <alexandre.bell...@free-electrons.com> Signed-off-by: Sebastian Hesselbarth <sebastian.hesselba...@gmail.com> --- Cc: Mike Turquette <mturque...@linaro.org> Cc: Alexandre Belloni <alexandre.bell...@free-electrons.com> Cc: Antoine Tenart <antoine.ten...@free-electrons.com> Cc: linux-arm-ker...@lists.infradead.org Cc: linux-kernel@vger.kernel.org --- drivers/clk/berlin/Makefile | 2 +- drivers/clk/berlin/berlin2-div.c | 326 +++++++++++++++++++++++++++++++++++++++ drivers/clk/berlin/berlin2-div.h | 80 ++++++++++ 3 files changed, 407 insertions(+), 1 deletion(-) create mode 100644 drivers/clk/berlin/berlin2-div.c create mode 100644 drivers/clk/berlin/berlin2-div.h diff --git a/drivers/clk/berlin/Makefile b/drivers/clk/berlin/Makefile index 9d3490e9782f..f0a7dc8b5e30 100644 --- a/drivers/clk/berlin/Makefile +++ b/drivers/clk/berlin/Makefile @@ -1 +1 @@ -obj-y += berlin2-avpll.o berlin2-pll.o +obj-y += berlin2-avpll.o berlin2-pll.o berlin2-div.o diff --git a/drivers/clk/berlin/berlin2-div.c b/drivers/clk/berlin/berlin2-div.c new file mode 100644 index 000000000000..96513a6e8ca7 --- /dev/null +++ b/drivers/clk/berlin/berlin2-div.c @@ -0,0 +1,326 @@ +/* + * Copyright (c) 2014 Marvell Technology Group Ltd. + * + * Alexandre Belloni <alexandre.bell...@free-electrons.com> + * Sebastian Hesselbarth <sebastian.hesselba...@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 == 1) { + 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); +} + +static const struct berlin2_div_map berlin2_single_div_map __initconst = { + .gate_offs = 0, + .gate_shift = 0, + .pll_select_offs = 0, + .pll_select_shift = 1, + .pll_switch_offs = 0, + .pll_switch_shift = 4, + .div_switch_offs = 0, + .div_switch_shift = 5, + .div3_switch_offs = 0, + .div3_switch_shift = 6, + .div_select_offs = 0, + .div_select_shift = 7, +}; + +static void __init berlin2_div_of_setup(struct device_node *np) +{ + const char *parent_names[9] = {}; + char *mux_name = "mux0"; + int num_parents = 0; + void __iomem *base; + struct clk *iclk; + struct clk *div; + char *div_name; + int n; + + iclk = of_clk_get_by_name(np, "mux_bypass"); + if (IS_ERR(iclk)) { + pr_err("%s: Missing mux bypass clock\n", np->full_name); + return; + } + parent_names[0] = __clk_get_name(iclk); + clk_put(iclk); + + /* collect mux input clock names */ + for (n = 0; n < 8; n++) { + sprintf(mux_name, "mux%d", n); + iclk = of_clk_get_by_name(np, mux_name); + if (IS_ERR(iclk)) + continue; + parent_names[1 + n] = __clk_get_name(iclk); + clk_put(iclk); + } + + base = of_iomap(np, 0); + if (!base) { + pr_err("%s: Unable to map div register\n", np->full_name); + return; + } + + div_name = of_clk_create_name(np); + div = berlin2_div_register(&berlin2_single_div_map, base, div_name, + BERLIN2_DIV_HAS_GATE | BERLIN2_DIV_HAS_MUX, + parent_names, num_parents, 0, NULL); + if (!IS_ERR(div)) + of_clk_add_provider(np, of_clk_src_simple_get, div); + + kfree(div_name); +} +CLK_OF_DECLARE(berlin2_div, "marvell,berlin2-div", berlin2_div_of_setup); diff --git a/drivers/clk/berlin/berlin2-div.h b/drivers/clk/berlin/berlin2-div.h new file mode 100644 index 000000000000..344865181712 --- /dev/null +++ b/drivers/clk/berlin/berlin2-div.h @@ -0,0 +1,80 @@ +/* + * Copyright (c) 2014 Marvell Technology Group Ltd. + * + * Alexandre Belloni <alexandre.bell...@free-electrons.com> + * Sebastian Hesselbarth <sebastian.hesselba...@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/>. + */ +#ifndef __BERLIN2_DIV_H +#define __BERLIN2_DIV_H + +#include <linux/clk.h> +#include <linux/spinlock.h> + +#define BERLIN2_DIV_HAS_GATE BIT(0) +#define BERLIN2_DIV_HAS_MUX BIT(1) + +#define BERLIN2_PLL_SELECT(_off, _sh) \ + .pll_select_offs = _off, \ + .pll_select_shift = _sh + +#define BERLIN2_PLL_SWITCH(_off, _sh) \ + .pll_switch_offs = _off, \ + .pll_switch_shift = _sh + +#define BERLIN2_DIV_SELECT(_off, _sh) \ + .div_select_offs = _off, \ + .div_select_shift = _sh + +#define BERLIN2_DIV_SWITCH(_off, _sh) \ + .div_switch_offs = _off, \ + .div_switch_shift = _sh + +#define BERLIN2_DIV_D3SWITCH(_off, _sh) \ + .div3_switch_offs = _off, \ + .div3_switch_shift = _sh + +#define BERLIN2_DIV_GATE(_off, _sh) \ + .gate_offs = _off, \ + .gate_shift = _sh + +struct berlin2_div_map { + u16 pll_select_offs; + u16 pll_switch_offs; + u16 div_select_offs; + u16 div_switch_offs; + u16 div3_switch_offs; + u16 gate_offs; + u8 pll_select_shift; + u8 pll_switch_shift; + u8 div_select_shift; + u8 div_switch_shift; + u8 div3_switch_shift; + u8 gate_shift; +}; + +struct berlin2_div_data { + const char *name; + unsigned long flags; + struct berlin2_div_map map; + u8 div_flags; +}; + +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); + +#endif /* BERLIN2_DIV_H */ -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
