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-rw-r--r--drivers/clk/ti/autoidle.c257
1 files changed, 257 insertions, 0 deletions
diff --git a/drivers/clk/ti/autoidle.c b/drivers/clk/ti/autoidle.c
new file mode 100644
index 000000000..27e6b9cb1
--- /dev/null
+++ b/drivers/clk/ti/autoidle.c
@@ -0,0 +1,257 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * TI clock autoidle support
+ *
+ * Copyright (C) 2013 Texas Instruments, Inc.
+ *
+ * Tero Kristo <t-kristo@ti.com>
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/clk/ti.h>
+
+#include "clock.h"
+
+struct clk_ti_autoidle {
+ struct clk_omap_reg reg;
+ u8 shift;
+ u8 flags;
+ const char *name;
+ struct list_head node;
+};
+
+#define AUTOIDLE_LOW 0x1
+
+static LIST_HEAD(autoidle_clks);
+
+/*
+ * we have some non-atomic read/write
+ * operations behind it, so lets
+ * take one lock for handling autoidle
+ * of all clocks
+ */
+static DEFINE_SPINLOCK(autoidle_spinlock);
+
+static int _omap2_clk_deny_idle(struct clk_hw_omap *clk)
+{
+ if (clk->ops && clk->ops->deny_idle) {
+ unsigned long irqflags;
+
+ spin_lock_irqsave(&autoidle_spinlock, irqflags);
+ clk->autoidle_count++;
+ if (clk->autoidle_count == 1)
+ clk->ops->deny_idle(clk);
+
+ spin_unlock_irqrestore(&autoidle_spinlock, irqflags);
+ }
+ return 0;
+}
+
+static int _omap2_clk_allow_idle(struct clk_hw_omap *clk)
+{
+ if (clk->ops && clk->ops->allow_idle) {
+ unsigned long irqflags;
+
+ spin_lock_irqsave(&autoidle_spinlock, irqflags);
+ clk->autoidle_count--;
+ if (clk->autoidle_count == 0)
+ clk->ops->allow_idle(clk);
+
+ spin_unlock_irqrestore(&autoidle_spinlock, irqflags);
+ }
+ return 0;
+}
+
+/**
+ * omap2_clk_deny_idle - disable autoidle on an OMAP clock
+ * @clk: struct clk * to disable autoidle for
+ *
+ * Disable autoidle on an OMAP clock.
+ */
+int omap2_clk_deny_idle(struct clk *clk)
+{
+ struct clk_hw *hw;
+
+ if (!clk)
+ return -EINVAL;
+
+ hw = __clk_get_hw(clk);
+
+ if (omap2_clk_is_hw_omap(hw)) {
+ struct clk_hw_omap *c = to_clk_hw_omap(hw);
+
+ return _omap2_clk_deny_idle(c);
+ }
+
+ return -EINVAL;
+}
+
+/**
+ * omap2_clk_allow_idle - enable autoidle on an OMAP clock
+ * @clk: struct clk * to enable autoidle for
+ *
+ * Enable autoidle on an OMAP clock.
+ */
+int omap2_clk_allow_idle(struct clk *clk)
+{
+ struct clk_hw *hw;
+
+ if (!clk)
+ return -EINVAL;
+
+ hw = __clk_get_hw(clk);
+
+ if (omap2_clk_is_hw_omap(hw)) {
+ struct clk_hw_omap *c = to_clk_hw_omap(hw);
+
+ return _omap2_clk_allow_idle(c);
+ }
+
+ return -EINVAL;
+}
+
+static void _allow_autoidle(struct clk_ti_autoidle *clk)
+{
+ u32 val;
+
+ val = ti_clk_ll_ops->clk_readl(&clk->reg);
+
+ if (clk->flags & AUTOIDLE_LOW)
+ val &= ~(1 << clk->shift);
+ else
+ val |= (1 << clk->shift);
+
+ ti_clk_ll_ops->clk_writel(val, &clk->reg);
+}
+
+static void _deny_autoidle(struct clk_ti_autoidle *clk)
+{
+ u32 val;
+
+ val = ti_clk_ll_ops->clk_readl(&clk->reg);
+
+ if (clk->flags & AUTOIDLE_LOW)
+ val |= (1 << clk->shift);
+ else
+ val &= ~(1 << clk->shift);
+
+ ti_clk_ll_ops->clk_writel(val, &clk->reg);
+}
+
+/**
+ * _clk_generic_allow_autoidle_all - enable autoidle for all clocks
+ *
+ * Enables hardware autoidle for all registered DT clocks, which have
+ * the feature.
+ */
+static void _clk_generic_allow_autoidle_all(void)
+{
+ struct clk_ti_autoidle *c;
+
+ list_for_each_entry(c, &autoidle_clks, node)
+ _allow_autoidle(c);
+}
+
+/**
+ * _clk_generic_deny_autoidle_all - disable autoidle for all clocks
+ *
+ * Disables hardware autoidle for all registered DT clocks, which have
+ * the feature.
+ */
+static void _clk_generic_deny_autoidle_all(void)
+{
+ struct clk_ti_autoidle *c;
+
+ list_for_each_entry(c, &autoidle_clks, node)
+ _deny_autoidle(c);
+}
+
+/**
+ * of_ti_clk_autoidle_setup - sets up hardware autoidle for a clock
+ * @node: pointer to the clock device node
+ *
+ * Checks if a clock has hardware autoidle support or not (check
+ * for presence of 'ti,autoidle-shift' property in the device tree
+ * node) and sets up the hardware autoidle feature for the clock
+ * if available. If autoidle is available, the clock is also added
+ * to the autoidle list for later processing. Returns 0 on success,
+ * negative error value on failure.
+ */
+int __init of_ti_clk_autoidle_setup(struct device_node *node)
+{
+ u32 shift;
+ struct clk_ti_autoidle *clk;
+ int ret;
+
+ /* Check if this clock has autoidle support or not */
+ if (of_property_read_u32(node, "ti,autoidle-shift", &shift))
+ return 0;
+
+ clk = kzalloc(sizeof(*clk), GFP_KERNEL);
+
+ if (!clk)
+ return -ENOMEM;
+
+ clk->shift = shift;
+ clk->name = ti_dt_clk_name(node);
+ ret = ti_clk_get_reg_addr(node, 0, &clk->reg);
+ if (ret) {
+ kfree(clk);
+ return ret;
+ }
+
+ if (of_property_read_bool(node, "ti,invert-autoidle-bit"))
+ clk->flags |= AUTOIDLE_LOW;
+
+ list_add(&clk->node, &autoidle_clks);
+
+ return 0;
+}
+
+/**
+ * omap2_clk_enable_autoidle_all - enable autoidle on all OMAP clocks that
+ * support it
+ *
+ * Enable clock autoidle on all OMAP clocks that have allow_idle
+ * function pointers associated with them. This function is intended
+ * to be temporary until support for this is added to the common clock
+ * code. Returns 0.
+ */
+int omap2_clk_enable_autoidle_all(void)
+{
+ int ret;
+
+ ret = omap2_clk_for_each(_omap2_clk_allow_idle);
+ if (ret)
+ return ret;
+
+ _clk_generic_allow_autoidle_all();
+
+ return 0;
+}
+
+/**
+ * omap2_clk_disable_autoidle_all - disable autoidle on all OMAP clocks that
+ * support it
+ *
+ * Disable clock autoidle on all OMAP clocks that have allow_idle
+ * function pointers associated with them. This function is intended
+ * to be temporary until support for this is added to the common clock
+ * code. Returns 0.
+ */
+int omap2_clk_disable_autoidle_all(void)
+{
+ int ret;
+
+ ret = omap2_clk_for_each(_omap2_clk_deny_idle);
+ if (ret)
+ return ret;
+
+ _clk_generic_deny_autoidle_all();
+
+ return 0;
+}