clk: st: Support for DIVMUX and PreDiv Clocks

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>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
This commit is contained in:
Gabriel FERNANDEZ 2014-02-27 16:24:14 +01:00 committed by Mike Turquette
parent c646cbf10f
commit 94885faf9d
3 changed files with 531 additions and 0 deletions

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@ -45,6 +45,7 @@ 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/

1
drivers/clk/st/Makefile Normal file
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@ -0,0 +1 @@
obj-y += clkgen-mux.o

529
drivers/clk/st/clkgen-mux.c Normal file
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@ -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);