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-rw-r--r--arch/c6x/platforms/pll.c444
1 files changed, 444 insertions, 0 deletions
diff --git a/arch/c6x/platforms/pll.c b/arch/c6x/platforms/pll.c
new file mode 100644
index 00000000000..3aa898f7ce4
--- /dev/null
+++ b/arch/c6x/platforms/pll.c
@@ -0,0 +1,444 @@
+/*
+ * Clock and PLL control for C64x+ devices
+ *
+ * Copyright (C) 2010, 2011 Texas Instruments.
+ * Contributed by: Mark Salter <msalter@redhat.com>
+ *
+ * Copied heavily from arm/mach-davinci/clock.c, so:
+ *
+ * Copyright (C) 2006-2007 Texas Instruments.
+ * Copyright (C) 2008-2009 Deep Root Systems, LLC
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/clkdev.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/err.h>
+
+#include <asm/clock.h>
+#include <asm/soc.h>
+
+static LIST_HEAD(clocks);
+static DEFINE_MUTEX(clocks_mutex);
+static DEFINE_SPINLOCK(clockfw_lock);
+
+static void __clk_enable(struct clk *clk)
+{
+ if (clk->parent)
+ __clk_enable(clk->parent);
+ clk->usecount++;
+}
+
+static void __clk_disable(struct clk *clk)
+{
+ if (WARN_ON(clk->usecount == 0))
+ return;
+ --clk->usecount;
+
+ if (clk->parent)
+ __clk_disable(clk->parent);
+}
+
+int clk_enable(struct clk *clk)
+{
+ unsigned long flags;
+
+ if (clk == NULL || IS_ERR(clk))
+ return -EINVAL;
+
+ spin_lock_irqsave(&clockfw_lock, flags);
+ __clk_enable(clk);
+ spin_unlock_irqrestore(&clockfw_lock, flags);
+
+ return 0;
+}
+EXPORT_SYMBOL(clk_enable);
+
+void clk_disable(struct clk *clk)
+{
+ unsigned long flags;
+
+ if (clk == NULL || IS_ERR(clk))
+ return;
+
+ spin_lock_irqsave(&clockfw_lock, flags);
+ __clk_disable(clk);
+ spin_unlock_irqrestore(&clockfw_lock, flags);
+}
+EXPORT_SYMBOL(clk_disable);
+
+unsigned long clk_get_rate(struct clk *clk)
+{
+ if (clk == NULL || IS_ERR(clk))
+ return -EINVAL;
+
+ return clk->rate;
+}
+EXPORT_SYMBOL(clk_get_rate);
+
+long clk_round_rate(struct clk *clk, unsigned long rate)
+{
+ if (clk == NULL || IS_ERR(clk))
+ return -EINVAL;
+
+ if (clk->round_rate)
+ return clk->round_rate(clk, rate);
+
+ return clk->rate;
+}
+EXPORT_SYMBOL(clk_round_rate);
+
+/* Propagate rate to children */
+static void propagate_rate(struct clk *root)
+{
+ struct clk *clk;
+
+ list_for_each_entry(clk, &root->children, childnode) {
+ if (clk->recalc)
+ clk->rate = clk->recalc(clk);
+ propagate_rate(clk);
+ }
+}
+
+int clk_set_rate(struct clk *clk, unsigned long rate)
+{
+ unsigned long flags;
+ int ret = -EINVAL;
+
+ if (clk == NULL || IS_ERR(clk))
+ return ret;
+
+ if (clk->set_rate)
+ ret = clk->set_rate(clk, rate);
+
+ spin_lock_irqsave(&clockfw_lock, flags);
+ if (ret == 0) {
+ if (clk->recalc)
+ clk->rate = clk->recalc(clk);
+ propagate_rate(clk);
+ }
+ spin_unlock_irqrestore(&clockfw_lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL(clk_set_rate);
+
+int clk_set_parent(struct clk *clk, struct clk *parent)
+{
+ unsigned long flags;
+
+ if (clk == NULL || IS_ERR(clk))
+ return -EINVAL;
+
+ /* Cannot change parent on enabled clock */
+ if (WARN_ON(clk->usecount))
+ return -EINVAL;
+
+ mutex_lock(&clocks_mutex);
+ clk->parent = parent;
+ list_del_init(&clk->childnode);
+ list_add(&clk->childnode, &clk->parent->children);
+ mutex_unlock(&clocks_mutex);
+
+ spin_lock_irqsave(&clockfw_lock, flags);
+ if (clk->recalc)
+ clk->rate = clk->recalc(clk);
+ propagate_rate(clk);
+ spin_unlock_irqrestore(&clockfw_lock, flags);
+
+ return 0;
+}
+EXPORT_SYMBOL(clk_set_parent);
+
+int clk_register(struct clk *clk)
+{
+ if (clk == NULL || IS_ERR(clk))
+ return -EINVAL;
+
+ if (WARN(clk->parent && !clk->parent->rate,
+ "CLK: %s parent %s has no rate!\n",
+ clk->name, clk->parent->name))
+ return -EINVAL;
+
+ mutex_lock(&clocks_mutex);
+ list_add_tail(&clk->node, &clocks);
+ if (clk->parent)
+ list_add_tail(&clk->childnode, &clk->parent->children);
+ mutex_unlock(&clocks_mutex);
+
+ /* If rate is already set, use it */
+ if (clk->rate)
+ return 0;
+
+ /* Else, see if there is a way to calculate it */
+ if (clk->recalc)
+ clk->rate = clk->recalc(clk);
+
+ /* Otherwise, default to parent rate */
+ else if (clk->parent)
+ clk->rate = clk->parent->rate;
+
+ return 0;
+}
+EXPORT_SYMBOL(clk_register);
+
+void clk_unregister(struct clk *clk)
+{
+ if (clk == NULL || IS_ERR(clk))
+ return;
+
+ mutex_lock(&clocks_mutex);
+ list_del(&clk->node);
+ list_del(&clk->childnode);
+ mutex_unlock(&clocks_mutex);
+}
+EXPORT_SYMBOL(clk_unregister);
+
+
+static u32 pll_read(struct pll_data *pll, int reg)
+{
+ return soc_readl(pll->base + reg);
+}
+
+static unsigned long clk_sysclk_recalc(struct clk *clk)
+{
+ u32 v, plldiv = 0;
+ struct pll_data *pll;
+ unsigned long rate = clk->rate;
+
+ if (WARN_ON(!clk->parent))
+ return rate;
+
+ rate = clk->parent->rate;
+
+ /* the parent must be a PLL */
+ if (WARN_ON(!clk->parent->pll_data))
+ return rate;
+
+ pll = clk->parent->pll_data;
+
+ /* If pre-PLL, source clock is before the multiplier and divider(s) */
+ if (clk->flags & PRE_PLL)
+ rate = pll->input_rate;
+
+ if (!clk->div) {
+ pr_debug("%s: (no divider) rate = %lu KHz\n",
+ clk->name, rate / 1000);
+ return rate;
+ }
+
+ if (clk->flags & FIXED_DIV_PLL) {
+ rate /= clk->div;
+ pr_debug("%s: (fixed divide by %d) rate = %lu KHz\n",
+ clk->name, clk->div, rate / 1000);
+ return rate;
+ }
+
+ v = pll_read(pll, clk->div);
+ if (v & PLLDIV_EN)
+ plldiv = (v & PLLDIV_RATIO_MASK) + 1;
+
+ if (plldiv == 0)
+ plldiv = 1;
+
+ rate /= plldiv;
+
+ pr_debug("%s: (divide by %d) rate = %lu KHz\n",
+ clk->name, plldiv, rate / 1000);
+
+ return rate;
+}
+
+static unsigned long clk_leafclk_recalc(struct clk *clk)
+{
+ if (WARN_ON(!clk->parent))
+ return clk->rate;
+
+ pr_debug("%s: (parent %s) rate = %lu KHz\n",
+ clk->name, clk->parent->name, clk->parent->rate / 1000);
+
+ return clk->parent->rate;
+}
+
+static unsigned long clk_pllclk_recalc(struct clk *clk)
+{
+ u32 ctrl, mult = 0, prediv = 0, postdiv = 0;
+ u8 bypass;
+ struct pll_data *pll = clk->pll_data;
+ unsigned long rate = clk->rate;
+
+ if (clk->flags & FIXED_RATE_PLL)
+ return rate;
+
+ ctrl = pll_read(pll, PLLCTL);
+ rate = pll->input_rate = clk->parent->rate;
+
+ if (ctrl & PLLCTL_PLLEN)
+ bypass = 0;
+ else
+ bypass = 1;
+
+ if (pll->flags & PLL_HAS_MUL) {
+ mult = pll_read(pll, PLLM);
+ mult = (mult & PLLM_PLLM_MASK) + 1;
+ }
+ if (pll->flags & PLL_HAS_PRE) {
+ prediv = pll_read(pll, PLLPRE);
+ if (prediv & PLLDIV_EN)
+ prediv = (prediv & PLLDIV_RATIO_MASK) + 1;
+ else
+ prediv = 0;
+ }
+ if (pll->flags & PLL_HAS_POST) {
+ postdiv = pll_read(pll, PLLPOST);
+ if (postdiv & PLLDIV_EN)
+ postdiv = (postdiv & PLLDIV_RATIO_MASK) + 1;
+ else
+ postdiv = 1;
+ }
+
+ if (!bypass) {
+ if (prediv)
+ rate /= prediv;
+ if (mult)
+ rate *= mult;
+ if (postdiv)
+ rate /= postdiv;
+
+ pr_debug("PLL%d: input = %luMHz, pre[%d] mul[%d] post[%d] "
+ "--> %luMHz output.\n",
+ pll->num, clk->parent->rate / 1000000,
+ prediv, mult, postdiv, rate / 1000000);
+ } else
+ pr_debug("PLL%d: input = %luMHz, bypass mode.\n",
+ pll->num, clk->parent->rate / 1000000);
+
+ return rate;
+}
+
+
+static void __init __init_clk(struct clk *clk)
+{
+ INIT_LIST_HEAD(&clk->node);
+ INIT_LIST_HEAD(&clk->children);
+ INIT_LIST_HEAD(&clk->childnode);
+
+ if (!clk->recalc) {
+
+ /* Check if clock is a PLL */
+ if (clk->pll_data)
+ clk->recalc = clk_pllclk_recalc;
+
+ /* Else, if it is a PLL-derived clock */
+ else if (clk->flags & CLK_PLL)
+ clk->recalc = clk_sysclk_recalc;
+
+ /* Otherwise, it is a leaf clock (PSC clock) */
+ else if (clk->parent)
+ clk->recalc = clk_leafclk_recalc;
+ }
+}
+
+void __init c6x_clks_init(struct clk_lookup *clocks)
+{
+ struct clk_lookup *c;
+ struct clk *clk;
+ size_t num_clocks = 0;
+
+ for (c = clocks; c->clk; c++) {
+ clk = c->clk;
+
+ __init_clk(clk);
+ clk_register(clk);
+ num_clocks++;
+
+ /* Turn on clocks that Linux doesn't otherwise manage */
+ if (clk->flags & ALWAYS_ENABLED)
+ clk_enable(clk);
+ }
+
+ clkdev_add_table(clocks, num_clocks);
+}
+
+#ifdef CONFIG_DEBUG_FS
+
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+#define CLKNAME_MAX 10 /* longest clock name */
+#define NEST_DELTA 2
+#define NEST_MAX 4
+
+static void
+dump_clock(struct seq_file *s, unsigned nest, struct clk *parent)
+{
+ char *state;
+ char buf[CLKNAME_MAX + NEST_DELTA * NEST_MAX];
+ struct clk *clk;
+ unsigned i;
+
+ if (parent->flags & CLK_PLL)
+ state = "pll";
+ else
+ state = "";
+
+ /* <nest spaces> name <pad to end> */
+ memset(buf, ' ', sizeof(buf) - 1);
+ buf[sizeof(buf) - 1] = 0;
+ i = strlen(parent->name);
+ memcpy(buf + nest, parent->name,
+ min(i, (unsigned)(sizeof(buf) - 1 - nest)));
+
+ seq_printf(s, "%s users=%2d %-3s %9ld Hz\n",
+ buf, parent->usecount, state, clk_get_rate(parent));
+ /* REVISIT show device associations too */
+
+ /* cost is now small, but not linear... */
+ list_for_each_entry(clk, &parent->children, childnode) {
+ dump_clock(s, nest + NEST_DELTA, clk);
+ }
+}
+
+static int c6x_ck_show(struct seq_file *m, void *v)
+{
+ struct clk *clk;
+
+ /*
+ * Show clock tree; We trust nonzero usecounts equate to PSC enables...
+ */
+ mutex_lock(&clocks_mutex);
+ list_for_each_entry(clk, &clocks, node)
+ if (!clk->parent)
+ dump_clock(m, 0, clk);
+ mutex_unlock(&clocks_mutex);
+
+ return 0;
+}
+
+static int c6x_ck_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, c6x_ck_show, NULL);
+}
+
+static const struct file_operations c6x_ck_operations = {
+ .open = c6x_ck_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int __init c6x_clk_debugfs_init(void)
+{
+ debugfs_create_file("c6x_clocks", S_IFREG | S_IRUGO, NULL, NULL,
+ &c6x_ck_operations);
+
+ return 0;
+}
+device_initcall(c6x_clk_debugfs_init);
+#endif /* CONFIG_DEBUG_FS */