On Mon, Nov 21, 2011 at 05:40:46PM -0800, Mike Turquette wrote:

Many platforms support simple gateable clks and fixed-rate clks that
should not be re-implemented by every platform.

This patch introduces a gateable clk with a common programming model of
gate control via a write of 1 bit to a register.  Both set-to-enable and
clear-to-enable are supported.

Also introduced is a fixed-rate clk which has no reprogrammable aspects.

The purpose of both types of clks is documented in drivers/clk/basic.c.

What I have seen is drivers/clk/clk-basic.c.

TODO: add support for a simple divider, simple mux and a dummy clk for
stubbing out platform support.

Based on original patch by Jeremy Kerr contribution by Jamie Iles.

Signed-off-by: Mike Turquette <redacted>
---
 drivers/clk/Kconfig     |    7 ++
 drivers/clk/Makefile    |    5 +-
 drivers/clk/clk-basic.c |  208 +++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/clk.h     |   35 ++++++++
 4 files changed, 253 insertions(+), 2 deletions(-)
 create mode 100644 drivers/clk/clk-basic.c

[...]

+int clk_register_gate(struct device *dev, const char *name, unsigned long flags,
+		struct clk *fixed_parent, void __iomem *reg, u8 bit_idx,
+		int set_to_enable)
+{
+	struct clk_hw_gate *gclk;
+	struct clk *clk;
+
+	gclk = kmalloc(sizeof(struct clk_hw_gate), GFP_KERNEL);
+
+	if (!gclk) {
+		pr_err("%s: could not allocate gated clk\n", __func__);
+		return -ENOMEM;
+	}
+
+	clk = &gclk->clk;
+
+	/* struct clk_hw_gate assignments */
+	gclk->fixed_parent = fixed_parent;
+	gclk->reg = reg;
+	gclk->bit_idx = bit_idx;
+
+	/* struct clk assignments */
+	clk->name = name;
+	clk->flags = flags;
+
+	if (set_to_enable)
+		clk->ops = &clk_hw_gate_set_enable_ops;
+	else
+		clk->ops = &clk_hw_gate_set_disable_ops;
+
+	clk_init(NULL, clk);
+
+	return 0;

The device tree support needs to get this 'struct clk *', so we may
want to have all these registering functions return the 'clk'.

+}

-- 
Regards,
Shawn