summaryrefslogtreecommitdiff
path: root/drivers/clk/ti/mux.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/clk/ti/mux.c')
-rw-r--r--drivers/clk/ti/mux.c246
1 files changed, 246 insertions, 0 deletions
diff --git a/drivers/clk/ti/mux.c b/drivers/clk/ti/mux.c
new file mode 100644
index 000000000000..0197a478720c
--- /dev/null
+++ b/drivers/clk/ti/mux.c
@@ -0,0 +1,246 @@
+/*
+ * TI Multiplexer Clock
+ *
+ * Copyright (C) 2013 Texas Instruments, Inc.
+ *
+ * Tero Kristo <t-kristo@ti.com>
+ *
+ * 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.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/clk/ti.h>
+
+#undef pr_fmt
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+#define to_clk_mux(_hw) container_of(_hw, struct clk_mux, hw)
+
+static u8 ti_clk_mux_get_parent(struct clk_hw *hw)
+{
+ struct clk_mux *mux = to_clk_mux(hw);
+ int num_parents = __clk_get_num_parents(hw->clk);
+ u32 val;
+
+ /*
+ * FIXME need a mux-specific flag to determine if val is bitwise or
+ * numeric. e.g. sys_clkin_ck's clksel field is 3 bits wide, but ranges
+ * from 0x1 to 0x7 (index starts at one)
+ * OTOH, pmd_trace_clk_mux_ck uses a separate bit for each clock, so
+ * val = 0x4 really means "bit 2, index starts at bit 0"
+ */
+ val = ti_clk_ll_ops->clk_readl(mux->reg) >> mux->shift;
+ val &= mux->mask;
+
+ if (mux->table) {
+ int i;
+
+ for (i = 0; i < num_parents; i++)
+ if (mux->table[i] == val)
+ return i;
+ return -EINVAL;
+ }
+
+ if (val && (mux->flags & CLK_MUX_INDEX_BIT))
+ val = ffs(val) - 1;
+
+ if (val && (mux->flags & CLK_MUX_INDEX_ONE))
+ val--;
+
+ if (val >= num_parents)
+ return -EINVAL;
+
+ return val;
+}
+
+static int ti_clk_mux_set_parent(struct clk_hw *hw, u8 index)
+{
+ struct clk_mux *mux = to_clk_mux(hw);
+ u32 val;
+ unsigned long flags = 0;
+
+ if (mux->table) {
+ index = mux->table[index];
+ } else {
+ if (mux->flags & CLK_MUX_INDEX_BIT)
+ index = (1 << ffs(index));
+
+ if (mux->flags & CLK_MUX_INDEX_ONE)
+ index++;
+ }
+
+ if (mux->lock)
+ spin_lock_irqsave(mux->lock, flags);
+
+ if (mux->flags & CLK_MUX_HIWORD_MASK) {
+ val = mux->mask << (mux->shift + 16);
+ } else {
+ val = ti_clk_ll_ops->clk_readl(mux->reg);
+ val &= ~(mux->mask << mux->shift);
+ }
+ val |= index << mux->shift;
+ ti_clk_ll_ops->clk_writel(val, mux->reg);
+
+ if (mux->lock)
+ spin_unlock_irqrestore(mux->lock, flags);
+
+ return 0;
+}
+
+const struct clk_ops ti_clk_mux_ops = {
+ .get_parent = ti_clk_mux_get_parent,
+ .set_parent = ti_clk_mux_set_parent,
+ .determine_rate = __clk_mux_determine_rate,
+};
+
+static struct clk *_register_mux(struct device *dev, const char *name,
+ const char **parent_names, u8 num_parents,
+ unsigned long flags, void __iomem *reg,
+ u8 shift, u32 mask, u8 clk_mux_flags,
+ u32 *table, spinlock_t *lock)
+{
+ struct clk_mux *mux;
+ struct clk *clk;
+ struct clk_init_data init;
+
+ /* allocate the mux */
+ mux = kzalloc(sizeof(*mux), GFP_KERNEL);
+ if (!mux) {
+ pr_err("%s: could not allocate mux clk\n", __func__);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ init.name = name;
+ init.ops = &ti_clk_mux_ops;
+ init.flags = flags | CLK_IS_BASIC;
+ init.parent_names = parent_names;
+ init.num_parents = num_parents;
+
+ /* struct clk_mux assignments */
+ mux->reg = reg;
+ mux->shift = shift;
+ mux->mask = mask;
+ mux->flags = clk_mux_flags;
+ mux->lock = lock;
+ mux->table = table;
+ mux->hw.init = &init;
+
+ clk = clk_register(dev, &mux->hw);
+
+ if (IS_ERR(clk))
+ kfree(mux);
+
+ return clk;
+}
+
+/**
+ * of_mux_clk_setup - Setup function for simple mux rate clock
+ * @node: DT node for the clock
+ *
+ * Sets up a basic clock multiplexer.
+ */
+static void of_mux_clk_setup(struct device_node *node)
+{
+ struct clk *clk;
+ void __iomem *reg;
+ int num_parents;
+ const char **parent_names;
+ int i;
+ u8 clk_mux_flags = 0;
+ u32 mask = 0;
+ u32 shift = 0;
+ u32 flags = 0;
+
+ num_parents = of_clk_get_parent_count(node);
+ if (num_parents < 2) {
+ pr_err("mux-clock %s must have parents\n", node->name);
+ return;
+ }
+ parent_names = kzalloc((sizeof(char *) * num_parents), GFP_KERNEL);
+ if (!parent_names)
+ goto cleanup;
+
+ for (i = 0; i < num_parents; i++)
+ parent_names[i] = of_clk_get_parent_name(node, i);
+
+ reg = ti_clk_get_reg_addr(node, 0);
+
+ if (!reg)
+ goto cleanup;
+
+ of_property_read_u32(node, "ti,bit-shift", &shift);
+
+ if (of_property_read_bool(node, "ti,index-starts-at-one"))
+ clk_mux_flags |= CLK_MUX_INDEX_ONE;
+
+ if (of_property_read_bool(node, "ti,set-rate-parent"))
+ flags |= CLK_SET_RATE_PARENT;
+
+ /* Generate bit-mask based on parent info */
+ mask = num_parents;
+ if (!(clk_mux_flags & CLK_MUX_INDEX_ONE))
+ mask--;
+
+ mask = (1 << fls(mask)) - 1;
+
+ clk = _register_mux(NULL, node->name, parent_names, num_parents, flags,
+ reg, shift, mask, clk_mux_flags, NULL, NULL);
+
+ if (!IS_ERR(clk))
+ of_clk_add_provider(node, of_clk_src_simple_get, clk);
+
+cleanup:
+ kfree(parent_names);
+}
+CLK_OF_DECLARE(mux_clk, "ti,mux-clock", of_mux_clk_setup);
+
+static void __init of_ti_composite_mux_clk_setup(struct device_node *node)
+{
+ struct clk_mux *mux;
+ int num_parents;
+ u32 val;
+
+ mux = kzalloc(sizeof(*mux), GFP_KERNEL);
+ if (!mux)
+ return;
+
+ mux->reg = ti_clk_get_reg_addr(node, 0);
+
+ if (!mux->reg)
+ goto cleanup;
+
+ if (!of_property_read_u32(node, "ti,bit-shift", &val))
+ mux->shift = val;
+
+ if (of_property_read_bool(node, "ti,index-starts-at-one"))
+ mux->flags |= CLK_MUX_INDEX_ONE;
+
+ num_parents = of_clk_get_parent_count(node);
+
+ if (num_parents < 2) {
+ pr_err("%s must have parents\n", node->name);
+ goto cleanup;
+ }
+
+ mux->mask = num_parents - 1;
+ mux->mask = (1 << fls(mux->mask)) - 1;
+
+ if (!ti_clk_add_component(node, &mux->hw, CLK_COMPONENT_TYPE_MUX))
+ return;
+
+cleanup:
+ kfree(mux);
+}
+CLK_OF_DECLARE(ti_composite_mux_clk_setup, "ti,composite-mux-clock",
+ of_ti_composite_mux_clk_setup);