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path: root/drivers/clk/versatile/clk-icst.c
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Diffstat (limited to 'drivers/clk/versatile/clk-icst.c')
-rw-r--r--drivers/clk/versatile/clk-icst.c66
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))