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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.c197
1 files changed, 164 insertions, 33 deletions
diff --git a/drivers/clk/versatile/clk-icst.c b/drivers/clk/versatile/clk-icst.c
index 08c5ee976..3bca438ec 100644
--- a/drivers/clk/versatile/clk-icst.c
+++ b/drivers/clk/versatile/clk-icst.c
@@ -3,7 +3,7 @@
* We wrap the custom interface from <asm/hardware/icst.h> into the generic
* clock framework.
*
- * Copyright (C) 2012 Linus Walleij
+ * Copyright (C) 2012-2015 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
@@ -19,9 +19,14 @@
#include <linux/err.h>
#include <linux/clk-provider.h>
#include <linux/io.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
#include "clk-icst.h"
+/* Magic unlocking token used on all Versatile boards */
+#define VERSATILE_LOCK_VAL 0xA05F
+
/**
* struct clk_icst - ICST VCO clock wrapper
* @hw: corresponding clock hardware entry
@@ -32,8 +37,9 @@
*/
struct clk_icst {
struct clk_hw hw;
- void __iomem *vcoreg;
- void __iomem *lockreg;
+ struct regmap *map;
+ u32 vcoreg_off;
+ u32 lockreg_off;
struct icst_params *params;
unsigned long rate;
};
@@ -41,53 +47,70 @@ struct clk_icst {
#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
+ * vco_get() - get ICST VCO settings from a certain ICST
+ * @icst: the ICST clock to get
+ * @vco: the VCO struct to return the value in
*/
-static struct icst_vco vco_get(void __iomem *vcoreg)
+static int vco_get(struct clk_icst *icst, struct icst_vco *vco)
{
u32 val;
- struct icst_vco vco;
+ int ret;
- val = readl(vcoreg);
- vco.v = val & 0x1ff;
- vco.r = (val >> 9) & 0x7f;
- vco.s = (val >> 16) & 03;
- return vco;
+ ret = regmap_read(icst->map, icst->vcoreg_off, &val);
+ if (ret)
+ return ret;
+ vco->v = val & 0x1ff;
+ vco->r = (val >> 9) & 0x7f;
+ vco->s = (val >> 16) & 03;
+ return 0;
}
/**
* 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
+ * @icst: the ICST clock to set
+ * @vco: the VCO struct to set the changes from
*/
-static void vco_set(void __iomem *lockreg,
- void __iomem *vcoreg,
- struct icst_vco vco)
+static int vco_set(struct clk_icst *icst, struct icst_vco vco)
{
u32 val;
+ int ret;
- val = readl(vcoreg) & ~0x7ffff;
+ ret = regmap_read(icst->map, icst->vcoreg_off, &val);
+ if (ret)
+ return ret;
+
+ /* Mask the 18 bits used by the VCO */
+ val &= ~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);
+ ret = regmap_write(icst->map, icst->lockreg_off, VERSATILE_LOCK_VAL);
+ if (ret)
+ return ret;
+ ret = regmap_write(icst->map, icst->vcoreg_off, val);
+ if (ret)
+ return ret;
/* This locks the VCO again */
- writel(0, lockreg);
+ ret = regmap_write(icst->map, icst->lockreg_off, 0);
+ if (ret)
+ return ret;
+ return 0;
}
-
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;
+ int ret;
if (parent_rate)
icst->params->ref = parent_rate;
- vco = vco_get(icst->vcoreg);
+ ret = vco_get(icst, &vco);
+ if (ret) {
+ pr_err("ICST: could not get VCO setting\n");
+ return 0;
+ }
icst->rate = icst_hz(icst->params, vco);
return icst->rate;
}
@@ -112,8 +135,7 @@ static int icst_set_rate(struct clk_hw *hw, unsigned long 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;
+ return vco_set(icst, vco);
}
static const struct clk_ops icst_ops = {
@@ -122,11 +144,11 @@ static const struct clk_ops icst_ops = {
.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)
+static struct clk *icst_clk_setup(struct device *dev,
+ const struct clk_icst_desc *desc,
+ const char *name,
+ const char *parent_name,
+ struct regmap *map)
{
struct clk *clk;
struct clk_icst *icst;
@@ -151,10 +173,11 @@ struct clk *icst_clk_register(struct device *dev,
init.flags = CLK_IS_ROOT;
init.parent_names = (parent_name ? &parent_name : NULL);
init.num_parents = (parent_name ? 1 : 0);
+ icst->map = map;
icst->hw.init = &init;
icst->params = pclone;
- icst->vcoreg = base + desc->vco_offset;
- icst->lockreg = base + desc->lock_offset;
+ icst->vcoreg_off = desc->vco_offset;
+ icst->lockreg_off = desc->lock_offset;
clk = clk_register(dev, &icst->hw);
if (IS_ERR(clk)) {
@@ -164,4 +187,112 @@ struct clk *icst_clk_register(struct device *dev,
return clk;
}
+
+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 regmap_config icst_regmap_conf = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = 4,
+ };
+ struct regmap *map;
+
+ map = regmap_init_mmio(dev, base, &icst_regmap_conf);
+ if (IS_ERR(map)) {
+ pr_err("could not initialize ICST regmap\n");
+ return ERR_CAST(map);
+ }
+ return icst_clk_setup(dev, desc, name, parent_name, map);
+}
EXPORT_SYMBOL_GPL(icst_clk_register);
+
+#ifdef CONFIG_OF
+/*
+ * In a device tree, an memory-mapped ICST clock appear as a child
+ * of a syscon node. Assume this and probe it only as a child of a
+ * syscon.
+ */
+
+static const struct icst_params icst525_params = {
+ .vco_max = ICST525_VCO_MAX_5V,
+ .vco_min = ICST525_VCO_MIN,
+ .vd_min = 8,
+ .vd_max = 263,
+ .rd_min = 3,
+ .rd_max = 65,
+ .s2div = icst525_s2div,
+ .idx2s = icst525_idx2s,
+};
+
+static const struct icst_params icst307_params = {
+ .vco_max = ICST307_VCO_MAX,
+ .vco_min = ICST307_VCO_MIN,
+ .vd_min = 4 + 8,
+ .vd_max = 511 + 8,
+ .rd_min = 1 + 2,
+ .rd_max = 127 + 2,
+ .s2div = icst307_s2div,
+ .idx2s = icst307_idx2s,
+};
+
+static void __init of_syscon_icst_setup(struct device_node *np)
+{
+ struct device_node *parent;
+ struct regmap *map;
+ struct clk_icst_desc icst_desc;
+ const char *name = np->name;
+ const char *parent_name;
+ struct clk *regclk;
+
+ /* We do not release this reference, we are using it perpetually */
+ parent = of_get_parent(np);
+ if (!parent) {
+ pr_err("no parent node for syscon ICST clock\n");
+ return;
+ }
+ map = syscon_node_to_regmap(parent);
+ if (IS_ERR(map)) {
+ pr_err("no regmap for syscon ICST clock parent\n");
+ return;
+ }
+
+ if (of_property_read_u32(np, "vco-offset", &icst_desc.vco_offset)) {
+ pr_err("no VCO register offset for ICST clock\n");
+ return;
+ }
+ if (of_property_read_u32(np, "lock-offset", &icst_desc.lock_offset)) {
+ pr_err("no lock register offset for ICST clock\n");
+ return;
+ }
+
+ if (of_device_is_compatible(np, "arm,syscon-icst525"))
+ icst_desc.params = &icst525_params;
+ else if (of_device_is_compatible(np, "arm,syscon-icst307"))
+ icst_desc.params = &icst307_params;
+ else {
+ pr_err("unknown ICST clock %s\n", name);
+ return;
+ }
+
+ /* Parent clock name is not the same as node parent */
+ parent_name = of_clk_get_parent_name(np, 0);
+
+ regclk = icst_clk_setup(NULL, &icst_desc, name, parent_name, map);
+ if (IS_ERR(regclk)) {
+ pr_err("error setting up syscon ICST clock %s\n", name);
+ return;
+ }
+ of_clk_add_provider(np, of_clk_src_simple_get, regclk);
+ pr_debug("registered syscon ICST clock %s\n", name);
+}
+
+CLK_OF_DECLARE(arm_syscon_icst525_clk,
+ "arm,syscon-icst525", of_syscon_icst_setup);
+CLK_OF_DECLARE(arm_syscon_icst307_clk,
+ "arm,syscon-icst307", of_syscon_icst_setup);
+
+#endif