This is a clock driver for the simple PLLs found on Berlin SoCs. With repect to PLL registers and features, BG2/BG2CD and BG2Q are slightly different, e.g. different allowed VCO dividers and bit shifts. Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@xxxxxxxxx> --- Cc: Mike Turquette <mturquette@xxxxxxxxxx> Cc: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx> Cc: Antoine Tenart <antoine.tenart@xxxxxxxxxxxxxxxxxx> Cc: Jason Cooper <jason@xxxxxxxxxxxxxx> Cc: Andrew Lunn <andrew@xxxxxxx> Cc: Gregory Clement <gregory.clement@xxxxxxxxxxxxxxxxxx> Cc: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx> Cc: devicetree@xxxxxxxxxxxxxxx Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx --- drivers/clk/berlin/berlin2-pll.c | 104 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 104 insertions(+) create mode 100644 drivers/clk/berlin/berlin2-pll.c diff --git a/drivers/clk/berlin/berlin2-pll.c b/drivers/clk/berlin/berlin2-pll.c new file mode 100644 index 000000000000..aef4ddd8db10 --- /dev/null +++ b/drivers/clk/berlin/berlin2-pll.c @@ -0,0 +1,104 @@ +/* + * Copyright (c) 2014 Marvell Technology Group Ltd. + * + * 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/clk-provider.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <asm/div64.h> + +#include "common.h" + +struct berlin2_pll { + struct clk_hw hw; + void __iomem *base; + struct berlin2_pll_map map; +}; + +#define to_berlin2_pll(hw) container_of(hw, struct berlin2_pll, hw) + +#define SPLL_CTRL0 0x00 +#define SPLL_CTRL1 0x04 +#define SPLL_CTRL2 0x08 +#define SPLL_CTRL3 0x0c +#define SPLL_CTRL4 0x10 + +#define FBDIV_MASK 0x1ff +#define RFDIV_MASK 0x1f +#define DIVSEL_MASK 0xf + +/* + * The output frequency formula for the pll is: + * clkout = fbdiv / refdiv * parent / vcodiv + */ +static unsigned long +berlin2_pll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) +{ + struct berlin2_pll *pll = to_berlin2_pll(hw); + struct berlin2_pll_map *map = &pll->map; + u32 val, fbdiv, rfdiv, vcodivsel, vcodiv; + u64 rate = parent_rate; + + val = readl_relaxed(pll->base + SPLL_CTRL0); + fbdiv = (val >> map->fbdiv_shift) & FBDIV_MASK; + rfdiv = (val >> map->rfdiv_shift) & RFDIV_MASK; + if (rfdiv == 0) { + pr_warn("%s has zero rfdiv\n", __clk_get_name(hw->clk)); + rfdiv = 1; + } + + val = readl_relaxed(pll->base + SPLL_CTRL1); + vcodivsel = (val >> map->divsel_shift) & DIVSEL_MASK; + vcodiv = map->vcodiv[vcodivsel]; + if (vcodiv == 0) { + pr_warn("%s has zero vcodiv (index %d)\n", + __clk_get_name(hw->clk), vcodivsel); + vcodiv = 1; + } + + rate *= fbdiv * map->mult; + do_div(rate, rfdiv * vcodiv); + + return (unsigned long)rate; +} + +static const struct clk_ops berlin2_pll_ops = { + .recalc_rate = berlin2_pll_recalc_rate, +}; + +struct clk * __init +berlin2_pll_register(const struct berlin2_pll_map *map, + void __iomem *base, const char *name, + const char *parent_name, unsigned long flags) +{ + struct clk_init_data init; + struct berlin2_pll *pll; + + pll = kzalloc(sizeof(*pll), GFP_KERNEL); + if (!pll) + return ERR_PTR(-ENOMEM); + + /* copy pll_map to allow __initconst */ + memcpy(&pll->map, map, sizeof(*map)); + pll->base = base; + pll->hw.init = &init; + init.name = name; + init.ops = &berlin2_pll_ops; + init.parent_names = &parent_name; + init.num_parents = 1; + init.flags = flags; + + return clk_register(NULL, &pll->hw); +} -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
