diff mbox

[v0,01/15] drivers: clk: st: Support for DIVMUX and PreDiv Clocks

Message ID 1393514668-17440-2-git-send-email-gabriel.fernandez@st.com (mailing list archive)
State New, archived
Headers show

Commit Message

Gabriel FERNANDEZ Feb. 27, 2014, 3:24 p.m. UTC
The patch supports the DIVMUX and PreDiv clocks used by ClockGenA(s)

DIVMUX clock : Divider-Multiplexer-Gate inside ClockGenA(s)
It includes support for each channel : 3-parent Multiplexer,
Divider for each Parent, Gate to switch OFF the output channel. The
clock is implemented using generic clocks implemented in the kernel
clk_divider and clk_mux.

PreDiv clock : Fixed Divider Clock used inside ClockGenA(s) to divide
the oscillator clock by factor-of-16. The clock is implemented using
generic clocks implemented in the kernel clk_divider.

Signed-off-by: Pankaj Dev <pankaj.dev@st.com>
Signed-off-by: Gabriel Fernandez <gabriel.fernandez@st.com>
---
 drivers/clk/Makefile        |   1 +
 drivers/clk/st/Makefile     |   1 +
 drivers/clk/st/clkgen-mux.c | 529 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 531 insertions(+)
 create mode 100644 drivers/clk/st/Makefile
 create mode 100644 drivers/clk/st/clkgen-mux.c

Comments

Mike Turquette March 25, 2014, 5:27 a.m. UTC | #1
Quoting Gabriel FERNANDEZ (2014-02-27 07:24:14)
> +/**
> + * DOC: Clock mux with a programmable divider on each of its three inputs.
> + *      The mux has an input setting which effectively gates its output.
> + *
> + * Traits of this clock:
> + * prepare - clk_(un)prepare only ensures parent is (un)prepared

Minor nitpick but it doesn't look like .prepare or .unprepare are
supported below. It looks like this copy/paste comment applies to most
of the clk patches as well.

It's a small problem and doesn't require a patch respin. But perhaps can
be cleaned up some day in the future.

Do you want me to take these patches directly or are you just looking
for an Ack?

Regards,
Mike
Gabriel FERNANDEZ March 25, 2014, 8:28 a.m. UTC | #2
Hi Mike,

I want that you take theses patches directly.

Many thanks


Best regards

Gabriel.


On 03/25/2014 06:27 AM, Mike Turquette wrote:
> Quoting Gabriel FERNANDEZ (2014-02-27 07:24:14)
>> +/**
>> + * DOC: Clock mux with a programmable divider on each of its three inputs.
>> + *      The mux has an input setting which effectively gates its output.
>> + *
>> + * Traits of this clock:
>> + * prepare - clk_(un)prepare only ensures parent is (un)prepared
> Minor nitpick but it doesn't look like .prepare or .unprepare are
> supported below. It looks like this copy/paste comment applies to most
> of the clk patches as well.
>
> It's a small problem and doesn't require a patch respin. But perhaps can
> be cleaned up some day in the future.
>
> Do you want me to take these patches directly or are you just looking
> for an Ack?
>
> Regards,
> Mike
Mike Turquette March 25, 2014, 10:59 p.m. UTC | #3
Quoting Gabriel Fernandez (2014-03-25 01:28:41)
> Hi Mike,
> 
> I want that you take theses patches directly.

Sure, I've taken patches #1-10 into clk-next.

Regards,
Mike

> 
> Many thanks
> 
> 
> Best regards
> 
> Gabriel.
> 
> 
> On 03/25/2014 06:27 AM, Mike Turquette wrote:
> > Quoting Gabriel FERNANDEZ (2014-02-27 07:24:14)
> >> +/**
> >> + * DOC: Clock mux with a programmable divider on each of its three inputs.
> >> + *      The mux has an input setting which effectively gates its output.
> >> + *
> >> + * Traits of this clock:
> >> + * prepare - clk_(un)prepare only ensures parent is (un)prepared
> > Minor nitpick but it doesn't look like .prepare or .unprepare are
> > supported below. It looks like this copy/paste comment applies to most
> > of the clk patches as well.
> >
> > It's a small problem and doesn't require a patch respin. But perhaps can
> > be cleaned up some day in the future.
> >
> > Do you want me to take these patches directly or are you just looking
> > for an Ack?
> >
> > Regards,
> > Mike
>
diff mbox

Patch

diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index a367a98..7867c511 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -43,6 +43,7 @@  obj-$(CONFIG_ARCH_SHMOBILE_MULTI)	+= shmobile/
 obj-$(CONFIG_ARCH_SIRF)			+= sirf/
 obj-$(CONFIG_ARCH_SOCFPGA)		+= socfpga/
 obj-$(CONFIG_PLAT_SPEAR)		+= spear/
+obj-$(CONFIG_ARCH_STI)			+= st/
 obj-$(CONFIG_ARCH_SUNXI)		+= sunxi/
 obj-$(CONFIG_ARCH_TEGRA)		+= tegra/
 obj-$(CONFIG_ARCH_OMAP2PLUS)		+= ti/
diff --git a/drivers/clk/st/Makefile b/drivers/clk/st/Makefile
new file mode 100644
index 0000000..e42b370
--- /dev/null
+++ b/drivers/clk/st/Makefile
@@ -0,0 +1 @@ 
+obj-y += clkgen-mux.o
diff --git a/drivers/clk/st/clkgen-mux.c b/drivers/clk/st/clkgen-mux.c
new file mode 100644
index 0000000..65d702c
--- /dev/null
+++ b/drivers/clk/st/clkgen-mux.c
@@ -0,0 +1,529 @@ 
+/*
+ * clkgen-mux.c: ST GEN-MUX Clock driver
+ *
+ * Copyright (C) 2014 STMicroelectronics (R&D) Limited
+ *
+ * Authors: Stephen Gallimore <stephen.gallimore@st.com>
+ *	    Pankaj Dev <pankaj.dev@st.com>
+ *
+ * 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/slab.h>
+#include <linux/of_address.h>
+#include <linux/clk-provider.h>
+
+static DEFINE_SPINLOCK(clkgena_divmux_lock);
+
+static const char ** __init clkgen_mux_get_parents(struct device_node *np,
+						       int *num_parents)
+{
+	const char **parents;
+	int nparents, i;
+
+	nparents = of_count_phandle_with_args(np, "clocks", "#clock-cells");
+	if (WARN_ON(nparents <= 0))
+		return ERR_PTR(-EINVAL);
+
+	parents = kzalloc(nparents * sizeof(const char *), GFP_KERNEL);
+	if (!parents)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < nparents; i++)
+		parents[i] = of_clk_get_parent_name(np, i);
+
+	*num_parents = nparents;
+	return parents;
+}
+
+/**
+ * DOC: Clock mux with a programmable divider on each of its three inputs.
+ *      The mux has an input setting which effectively gates its output.
+ *
+ * Traits of this clock:
+ * prepare - clk_(un)prepare only ensures parent is (un)prepared
+ * enable - clk_enable and clk_disable are functional & control gating
+ * rate - set rate is supported
+ * parent - set/get parent
+ */
+
+#define NUM_INPUTS 3
+
+struct clkgena_divmux {
+	struct clk_hw hw;
+	/* Subclassed mux and divider structures */
+	struct clk_mux mux;
+	struct clk_divider div[NUM_INPUTS];
+	/* Enable/running feedback register bits for each input */
+	void __iomem *feedback_reg[NUM_INPUTS];
+	int feedback_bit_idx;
+
+	u8              muxsel;
+};
+
+#define to_clkgena_divmux(_hw) container_of(_hw, struct clkgena_divmux, hw)
+
+struct clkgena_divmux_data {
+	int num_outputs;
+	int mux_offset;
+	int mux_offset2;
+	int mux_start_bit;
+	int div_offsets[NUM_INPUTS];
+	int fb_offsets[NUM_INPUTS];
+	int fb_start_bit_idx;
+};
+
+#define CKGAX_CLKOPSRC_SWITCH_OFF 0x3
+
+static int clkgena_divmux_is_running(struct clkgena_divmux *mux)
+{
+	u32 regval = readl(mux->feedback_reg[mux->muxsel]);
+	u32 running = regval & BIT(mux->feedback_bit_idx);
+	return !!running;
+}
+
+static int clkgena_divmux_enable(struct clk_hw *hw)
+{
+	struct clkgena_divmux *genamux = to_clkgena_divmux(hw);
+	struct clk_hw *mux_hw = &genamux->mux.hw;
+	unsigned long timeout;
+	int ret = 0;
+
+	mux_hw->clk = hw->clk;
+
+	ret = clk_mux_ops.set_parent(mux_hw, genamux->muxsel);
+	if (ret)
+		return ret;
+
+	timeout = jiffies + msecs_to_jiffies(10);
+
+	while (!clkgena_divmux_is_running(genamux)) {
+		if (time_after(jiffies, timeout))
+			return -ETIMEDOUT;
+		cpu_relax();
+	}
+
+	return 0;
+}
+
+static void clkgena_divmux_disable(struct clk_hw *hw)
+{
+	struct clkgena_divmux *genamux = to_clkgena_divmux(hw);
+	struct clk_hw *mux_hw = &genamux->mux.hw;
+
+	mux_hw->clk = hw->clk;
+
+	clk_mux_ops.set_parent(mux_hw, CKGAX_CLKOPSRC_SWITCH_OFF);
+}
+
+static int clkgena_divmux_is_enabled(struct clk_hw *hw)
+{
+	struct clkgena_divmux *genamux = to_clkgena_divmux(hw);
+	struct clk_hw *mux_hw = &genamux->mux.hw;
+
+	mux_hw->clk = hw->clk;
+
+	return (s8)clk_mux_ops.get_parent(mux_hw) > 0;
+}
+
+u8 clkgena_divmux_get_parent(struct clk_hw *hw)
+{
+	struct clkgena_divmux *genamux = to_clkgena_divmux(hw);
+	struct clk_hw *mux_hw = &genamux->mux.hw;
+
+	mux_hw->clk = hw->clk;
+
+	genamux->muxsel = clk_mux_ops.get_parent(mux_hw);
+	if ((s8)genamux->muxsel < 0) {
+		pr_debug("%s: %s: Invalid parent, setting to default.\n",
+		      __func__, __clk_get_name(hw->clk));
+		genamux->muxsel = 0;
+	}
+
+	return genamux->muxsel;
+}
+
+static int clkgena_divmux_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct clkgena_divmux *genamux = to_clkgena_divmux(hw);
+
+	if (index >= CKGAX_CLKOPSRC_SWITCH_OFF)
+		return -EINVAL;
+
+	genamux->muxsel = index;
+
+	/*
+	 * If the mux is already enabled, call enable directly to set the
+	 * new mux position and wait for it to start running again. Otherwise
+	 * do nothing.
+	 */
+	if (clkgena_divmux_is_enabled(hw))
+		clkgena_divmux_enable(hw);
+
+	return 0;
+}
+
+unsigned long clkgena_divmux_recalc_rate(struct clk_hw *hw,
+		unsigned long parent_rate)
+{
+	struct clkgena_divmux *genamux = to_clkgena_divmux(hw);
+	struct clk_hw *div_hw = &genamux->div[genamux->muxsel].hw;
+
+	div_hw->clk = hw->clk;
+
+	return clk_divider_ops.recalc_rate(div_hw, parent_rate);
+}
+
+static int clkgena_divmux_set_rate(struct clk_hw *hw, unsigned long rate,
+				unsigned long parent_rate)
+{
+	struct clkgena_divmux *genamux = to_clkgena_divmux(hw);
+	struct clk_hw *div_hw = &genamux->div[genamux->muxsel].hw;
+
+	div_hw->clk = hw->clk;
+
+	return clk_divider_ops.set_rate(div_hw, rate, parent_rate);
+}
+
+static long clkgena_divmux_round_rate(struct clk_hw *hw, unsigned long rate,
+				   unsigned long *prate)
+{
+	struct clkgena_divmux *genamux = to_clkgena_divmux(hw);
+	struct clk_hw *div_hw = &genamux->div[genamux->muxsel].hw;
+
+	div_hw->clk = hw->clk;
+
+	return clk_divider_ops.round_rate(div_hw, rate, prate);
+}
+
+static const struct clk_ops clkgena_divmux_ops = {
+	.enable = clkgena_divmux_enable,
+	.disable = clkgena_divmux_disable,
+	.is_enabled = clkgena_divmux_is_enabled,
+	.get_parent = clkgena_divmux_get_parent,
+	.set_parent = clkgena_divmux_set_parent,
+	.round_rate = clkgena_divmux_round_rate,
+	.recalc_rate = clkgena_divmux_recalc_rate,
+	.set_rate = clkgena_divmux_set_rate,
+};
+
+/**
+ * clk_register_genamux - register a genamux clock with the clock framework
+ */
+struct clk *clk_register_genamux(const char *name,
+				const char **parent_names, u8 num_parents,
+				void __iomem *reg,
+				const struct clkgena_divmux_data *muxdata,
+				u32 idx)
+{
+	/*
+	 * Fixed constants across all ClockgenA variants
+	 */
+	const int mux_width = 2;
+	const int divider_width = 5;
+	struct clkgena_divmux *genamux;
+	struct clk *clk;
+	struct clk_init_data init;
+	int i;
+
+	genamux = kzalloc(sizeof(*genamux), GFP_KERNEL);
+	if (!genamux)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.ops = &clkgena_divmux_ops;
+	init.flags = CLK_IS_BASIC;
+	init.parent_names = parent_names;
+	init.num_parents = num_parents;
+
+	genamux->mux.lock  = &clkgena_divmux_lock;
+	genamux->mux.mask = BIT(mux_width) - 1;
+	genamux->mux.shift = muxdata->mux_start_bit + (idx * mux_width);
+	if (genamux->mux.shift > 31) {
+		/*
+		 * We have spilled into the second mux register so
+		 * adjust the register address and the bit shift accordingly
+		 */
+		genamux->mux.reg = reg + muxdata->mux_offset2;
+		genamux->mux.shift -= 32;
+	} else {
+		genamux->mux.reg   = reg + muxdata->mux_offset;
+	}
+
+	for (i = 0; i < NUM_INPUTS; i++) {
+		/*
+		 * Divider config for each input
+		 */
+		void __iomem *divbase = reg + muxdata->div_offsets[i];
+		genamux->div[i].width = divider_width;
+		genamux->div[i].reg = divbase + (idx * sizeof(u32));
+
+		/*
+		 * Mux enabled/running feedback register for each input.
+		 */
+		genamux->feedback_reg[i] = reg + muxdata->fb_offsets[i];
+	}
+
+	genamux->feedback_bit_idx = muxdata->fb_start_bit_idx + idx;
+	genamux->hw.init = &init;
+
+	clk = clk_register(NULL, &genamux->hw);
+	if (IS_ERR(clk)) {
+		kfree(genamux);
+		goto err;
+	}
+
+	pr_debug("%s: parent %s rate %lu\n",
+			__clk_get_name(clk),
+			__clk_get_name(clk_get_parent(clk)),
+			clk_get_rate(clk));
+err:
+	return clk;
+}
+
+static struct clkgena_divmux_data st_divmux_c65hs = {
+	.num_outputs = 4,
+	.mux_offset = 0x14,
+	.mux_start_bit = 0,
+	.div_offsets = { 0x800, 0x900, 0xb00 },
+	.fb_offsets = { 0x18, 0x1c, 0x20 },
+	.fb_start_bit_idx = 0,
+};
+
+static struct clkgena_divmux_data st_divmux_c65ls = {
+	.num_outputs = 14,
+	.mux_offset = 0x14,
+	.mux_offset2 = 0x24,
+	.mux_start_bit = 8,
+	.div_offsets = { 0x810, 0xa10, 0xb10 },
+	.fb_offsets = { 0x18, 0x1c, 0x20 },
+	.fb_start_bit_idx = 4,
+};
+
+static struct clkgena_divmux_data st_divmux_c32odf0 = {
+	.num_outputs = 8,
+	.mux_offset = 0x1c,
+	.mux_start_bit = 0,
+	.div_offsets = { 0x800, 0x900, 0xa60 },
+	.fb_offsets = { 0x2c, 0x24, 0x28 },
+	.fb_start_bit_idx = 0,
+};
+
+static struct clkgena_divmux_data st_divmux_c32odf1 = {
+	.num_outputs = 8,
+	.mux_offset = 0x1c,
+	.mux_start_bit = 16,
+	.div_offsets = { 0x820, 0x980, 0xa80 },
+	.fb_offsets = { 0x2c, 0x24, 0x28 },
+	.fb_start_bit_idx = 8,
+};
+
+static struct clkgena_divmux_data st_divmux_c32odf2 = {
+	.num_outputs = 8,
+	.mux_offset = 0x20,
+	.mux_start_bit = 0,
+	.div_offsets = { 0x840, 0xa20, 0xb10 },
+	.fb_offsets = { 0x2c, 0x24, 0x28 },
+	.fb_start_bit_idx = 16,
+};
+
+static struct clkgena_divmux_data st_divmux_c32odf3 = {
+	.num_outputs = 8,
+	.mux_offset = 0x20,
+	.mux_start_bit = 16,
+	.div_offsets = { 0x860, 0xa40, 0xb30 },
+	.fb_offsets = { 0x2c, 0x24, 0x28 },
+	.fb_start_bit_idx = 24,
+};
+
+static struct of_device_id clkgena_divmux_of_match[] = {
+	{
+		.compatible = "st,clkgena-divmux-c65-hs",
+		.data = &st_divmux_c65hs,
+	},
+	{
+		.compatible = "st,clkgena-divmux-c65-ls",
+		.data = &st_divmux_c65ls,
+	},
+	{
+		.compatible = "st,clkgena-divmux-c32-odf0",
+		.data = &st_divmux_c32odf0,
+	},
+	{
+		.compatible = "st,clkgena-divmux-c32-odf1",
+		.data = &st_divmux_c32odf1,
+	},
+	{
+		.compatible = "st,clkgena-divmux-c32-odf2",
+		.data = &st_divmux_c32odf2,
+	},
+	{
+		.compatible = "st,clkgena-divmux-c32-odf3",
+		.data = &st_divmux_c32odf3,
+	},
+	{}
+};
+
+static void __iomem * __init clkgen_get_register_base(
+				struct device_node *np)
+{
+	struct device_node *pnode;
+	void __iomem *reg = NULL;
+
+	pnode = of_get_parent(np);
+	if (!pnode)
+		return NULL;
+
+	reg = of_iomap(pnode, 0);
+
+	of_node_put(pnode);
+	return reg;
+}
+
+void __init st_of_clkgena_divmux_setup(struct device_node *np)
+{
+	const struct of_device_id *match;
+	const struct clkgena_divmux_data *data;
+	struct clk_onecell_data *clk_data;
+	void __iomem *reg;
+	const char **parents;
+	int num_parents = 0, i;
+
+	match = of_match_node(clkgena_divmux_of_match, np);
+	if (WARN_ON(!match))
+		return;
+
+	data = (struct clkgena_divmux_data *)match->data;
+
+	reg = clkgen_get_register_base(np);
+	if (!reg)
+		return;
+
+	parents = clkgen_mux_get_parents(np, &num_parents);
+	if (IS_ERR(parents))
+		return;
+
+	clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL);
+	if (!clk_data)
+		goto err;
+
+	clk_data->clk_num = data->num_outputs;
+	clk_data->clks = kzalloc(clk_data->clk_num * sizeof(struct clk *),
+				 GFP_KERNEL);
+
+	if (!clk_data->clks)
+		goto err;
+
+	for (i = 0; i < clk_data->clk_num; i++) {
+		struct clk *clk;
+		const char *clk_name;
+
+		if (of_property_read_string_index(np, "clock-output-names",
+						  i, &clk_name))
+			break;
+
+		/*
+		 * If we read an empty clock name then the output is unused
+		 */
+		if (*clk_name == '\0')
+			continue;
+
+		clk = clk_register_genamux(clk_name, parents, num_parents,
+					   reg, data, i);
+
+		if (IS_ERR(clk))
+			goto err;
+
+		clk_data->clks[i] = clk;
+	}
+
+	kfree(parents);
+
+	of_clk_add_provider(np, of_clk_src_onecell_get, clk_data);
+	return;
+err:
+	if (clk_data)
+		kfree(clk_data->clks);
+
+	kfree(clk_data);
+	kfree(parents);
+}
+CLK_OF_DECLARE(clkgenadivmux, "st,clkgena-divmux", st_of_clkgena_divmux_setup);
+
+struct clkgena_prediv_data {
+	u32 offset;
+	u8 shift;
+	struct clk_div_table *table;
+};
+
+static struct clk_div_table prediv_table16[] = {
+	{ .val = 0, .div = 1 },
+	{ .val = 1, .div = 16 },
+	{ .div = 0 },
+};
+
+static struct clkgena_prediv_data prediv_c65_data = {
+	.offset = 0x4c,
+	.shift = 31,
+	.table = prediv_table16,
+};
+
+static struct clkgena_prediv_data prediv_c32_data = {
+	.offset = 0x50,
+	.shift = 1,
+	.table = prediv_table16,
+};
+
+static struct of_device_id clkgena_prediv_of_match[] = {
+	{ .compatible = "st,clkgena-prediv-c65", .data = &prediv_c65_data },
+	{ .compatible = "st,clkgena-prediv-c32", .data = &prediv_c32_data },
+	{}
+};
+
+void __init st_of_clkgena_prediv_setup(struct device_node *np)
+{
+	const struct of_device_id *match;
+	void __iomem *reg;
+	const char *parent_name, *clk_name;
+	struct clk *clk;
+	struct clkgena_prediv_data *data;
+
+	match = of_match_node(clkgena_prediv_of_match, np);
+	if (!match) {
+		pr_err("%s: No matching data\n", __func__);
+		return;
+	}
+
+	data = (struct clkgena_prediv_data *)match->data;
+
+	reg = clkgen_get_register_base(np);
+	if (!reg)
+		return;
+
+	parent_name = of_clk_get_parent_name(np, 0);
+	if (!parent_name)
+		return;
+
+	if (of_property_read_string_index(np, "clock-output-names",
+					  0, &clk_name))
+		return;
+
+	clk = clk_register_divider_table(NULL, clk_name, parent_name, 0,
+					 reg + data->offset, data->shift, 1,
+					 0, data->table, NULL);
+	if (IS_ERR(clk))
+		return;
+
+	of_clk_add_provider(np, of_clk_src_simple_get, clk);
+	pr_debug("%s: parent %s rate %u\n",
+		__clk_get_name(clk),
+		__clk_get_name(clk_get_parent(clk)),
+		(unsigned int)clk_get_rate(clk));
+
+	return;
+}
+CLK_OF_DECLARE(clkgenaprediv, "st,clkgena-prediv", st_of_clkgena_prediv_setup);