Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / clk / versatile / clk-icst.c

diff --git a/kernel/drivers/clk/versatile/clk-icst.c b/kernel/drivers/clk/versatile/clk-icst.c
new file mode 100644 (file)
index 0000000..bc96f10
--- /dev/null
+++ b/kernel/drivers/clk/versatile/clk-icst.c
@@ -0,0 +1,164 @@
+/*
+ * Driver for the ICST307 VCO clock found in the ARM Reference designs.
+ * 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.
+ */
+#include <linux/clk.h>
+#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
+ */
+struct clk_icst {
+       struct clk_hw hw;
+       void __iomem *vcoreg;
+       void __iomem *lockreg;
+       struct icst_params *params;
+       unsigned long rate;
+};
+
+#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;
+
+       if (parent_rate)
+               icst->params->ref = parent_rate;
+       vco = vco_get(icst->vcoreg);
+       icst->rate = icst_hz(icst->params, vco);
+       return icst->rate;
+}
+
+static long icst_round_rate(struct clk_hw *hw, unsigned long rate,
+                           unsigned long *prate)
+{
+       struct clk_icst *icst = to_icst(hw);
+       struct icst_vco vco;
+
+       vco = icst_hz_to_vco(icst->params, rate);
+       return icst_hz(icst->params, vco);
+}
+
+static int icst_set_rate(struct clk_hw *hw, unsigned long rate,
+                        unsigned long parent_rate)
+{
+       struct clk_icst *icst = to_icst(hw);
+       struct icst_vco vco;
+
+       if (parent_rate)
+               icst->params->ref = parent_rate;
+       vco = icst_hz_to_vco(icst->params, rate);
+       icst->rate = icst_hz(icst->params, vco);
+       vco_set(icst->lockreg, icst->vcoreg, vco);
+       return 0;
+}
+
+static const struct clk_ops icst_ops = {
+       .recalc_rate = icst_recalc_rate,
+       .round_rate = icst_round_rate,
+       .set_rate = icst_set_rate,
+};
+
+struct clk *icst_clk_register(struct device *dev,
+                       const struct clk_icst_desc *desc,
+                       const char *name,
+                       const char *parent_name,
+                       void __iomem *base)
+{
+       struct clk *clk;
+       struct clk_icst *icst;
+       struct clk_init_data init;
+       struct icst_params *pclone;
+
+       icst = kzalloc(sizeof(struct clk_icst), GFP_KERNEL);
+       if (!icst) {
+               pr_err("could not allocate ICST clock!\n");
+               return ERR_PTR(-ENOMEM);
+       }
+
+       pclone = kmemdup(desc->params, sizeof(*pclone), GFP_KERNEL);
+       if (!pclone) {
+               kfree(icst);
+               pr_err("could not clone ICST params\n");
+               return ERR_PTR(-ENOMEM);
+       }
+
+       init.name = name;
+       init.ops = &icst_ops;
+       init.flags = CLK_IS_ROOT;
+       init.parent_names = (parent_name ? &parent_name : NULL);
+       init.num_parents = (parent_name ? 1 : 0);
+       icst->hw.init = &init;
+       icst->params = pclone;
+       icst->vcoreg = base + desc->vco_offset;
+       icst->lockreg = base + desc->lock_offset;
+
+       clk = clk_register(dev, &icst->hw);
+       if (IS_ERR(clk))
+               kfree(icst);
+
+       return clk;
+}
+EXPORT_SYMBOL_GPL(icst_clk_register);