diff options
Diffstat (limited to 'drivers/clk/versatile/clk-icst.c')
-rw-r--r-- | drivers/clk/versatile/clk-icst.c | 66 |
1 files changed, 57 insertions, 9 deletions
diff --git a/drivers/clk/versatile/clk-icst.c b/drivers/clk/versatile/clk-icst.c index f555b50a5fa..67ccf4aa727 100644 --- a/drivers/clk/versatile/clk-icst.c +++ b/drivers/clk/versatile/clk-icst.c @@ -3,6 +3,12 @@ * We wrap the custom interface from <asm/hardware/icst.h> into the generic * clock framework. * + * Copyright (C) 2012 Linus Walleij + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * * TODO: when all ARM reference designs are migrated to generic clocks, the * ICST clock code from the ARM tree should probably be merged into this * file. @@ -11,33 +17,74 @@ #include <linux/clkdev.h> #include <linux/err.h> #include <linux/clk-provider.h> +#include <linux/io.h> #include "clk-icst.h" /** * struct clk_icst - ICST VCO clock wrapper * @hw: corresponding clock hardware entry + * @vcoreg: VCO register address + * @lockreg: VCO lock register address * @params: parameters for this ICST instance * @rate: current rate - * @setvco: function to commit ICST settings to hardware */ struct clk_icst { struct clk_hw hw; + void __iomem *vcoreg; + void __iomem *lockreg; const struct icst_params *params; unsigned long rate; - struct icst_vco (*getvco)(void); - void (*setvco)(struct icst_vco); }; #define to_icst(_hw) container_of(_hw, struct clk_icst, hw) +/** + * vco_get() - get ICST VCO settings from a certain register + * @vcoreg: register containing the VCO settings + */ +static struct icst_vco vco_get(void __iomem *vcoreg) +{ + u32 val; + struct icst_vco vco; + + val = readl(vcoreg); + vco.v = val & 0x1ff; + vco.r = (val >> 9) & 0x7f; + vco.s = (val >> 16) & 03; + return vco; +} + +/** + * vco_set() - commit changes to an ICST VCO + * @locreg: register to poke to unlock the VCO for writing + * @vcoreg: register containing the VCO settings + * @vco: ICST VCO parameters to commit + */ +static void vco_set(void __iomem *lockreg, + void __iomem *vcoreg, + struct icst_vco vco) +{ + u32 val; + + val = readl(vcoreg) & ~0x7ffff; + val |= vco.v | (vco.r << 9) | (vco.s << 16); + + /* This magic unlocks the VCO so it can be controlled */ + writel(0xa05f, lockreg); + writel(val, vcoreg); + /* This locks the VCO again */ + writel(0, lockreg); +} + + static unsigned long icst_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { struct clk_icst *icst = to_icst(hw); struct icst_vco vco; - vco = icst->getvco(); + vco = vco_get(icst->vcoreg); icst->rate = icst_hz(icst->params, vco); return icst->rate; } @@ -60,7 +107,7 @@ static int icst_set_rate(struct clk_hw *hw, unsigned long rate, vco = icst_hz_to_vco(icst->params, rate); icst->rate = icst_hz(icst->params, vco); - icst->setvco(vco); + vco_set(icst->vcoreg, icst->lockreg, vco); return 0; } @@ -70,8 +117,9 @@ static const struct clk_ops icst_ops = { .set_rate = icst_set_rate, }; -struct clk * __init icst_clk_register(struct device *dev, - const struct clk_icst_desc *desc) +struct clk *icst_clk_register(struct device *dev, + const struct clk_icst_desc *desc, + void __iomem *base) { struct clk *clk; struct clk_icst *icst; @@ -89,8 +137,8 @@ struct clk * __init icst_clk_register(struct device *dev, init.num_parents = 0; icst->hw.init = &init; icst->params = desc->params; - icst->getvco = desc->getvco; - icst->setvco = desc->setvco; + icst->vcoreg = base + desc->vco_offset; + icst->lockreg = base + desc->lock_offset; clk = clk_register(dev, &icst->hw); if (IS_ERR(clk)) |