alistair23-linux/drivers/clk/st/clkgen-mux.c
Gabriel Fernandez 46a57afdd7 drivers: clk: st: PLL rate change implementation for DVFS
Change A9 PLL rate, as per requirement from the cpufreq framework,
for DVFS. For rate change, the A9 clock needs to be temporarily sourced
from PLL external to A9 and then sourced back to A9-PLL

Signed-off-by: Pankaj Dev <pankaj.dev@st.com>
Signed-off-by: Gabriel Fernandez <gabriel.fernandez@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-08 23:52:58 -07:00

841 lines
19 KiB
C

/*
* 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.h>
#include <linux/clk-provider.h>
#include "clkgen.h"
static DEFINE_SPINLOCK(clkgena_divmux_lock);
static DEFINE_SPINLOCK(clkgenf_lock);
static const char ** __init clkgen_mux_get_parents(struct device_node *np,
int *num_parents)
{
const char **parents;
int nparents;
nparents = of_clk_get_parent_count(np);
if (WARN_ON(nparents <= 0))
return ERR_PTR(-EINVAL);
parents = kcalloc(nparents, sizeof(const char *), GFP_KERNEL);
if (!parents)
return ERR_PTR(-ENOMEM);
*num_parents = of_clk_parent_fill(np, 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;
__clk_hw_set_clk(mux_hw, hw);
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;
__clk_hw_set_clk(mux_hw, hw);
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;
__clk_hw_set_clk(mux_hw, hw);
return (s8)clk_mux_ops.get_parent(mux_hw) > 0;
}
static 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;
__clk_hw_set_clk(mux_hw, hw);
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_hw_get_name(hw));
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;
}
static 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;
__clk_hw_set_clk(div_hw, hw);
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;
__clk_hw_set_clk(div_hw, hw);
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;
__clk_hw_set_clk(div_hw, hw);
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
*/
static struct clk * __init 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 | CLK_GET_RATE_NOCACHE;
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 const 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;
pnode = of_get_parent(np);
if (!pnode)
return NULL;
reg = of_iomap(pnode, 0);
of_node_put(pnode);
return reg;
}
static 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 = match->data;
reg = clkgen_get_register_base(np);
if (!reg)
return;
parents = clkgen_mux_get_parents(np, &num_parents);
if (IS_ERR(parents))
goto err_parents;
clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL);
if (!clk_data)
goto err_alloc;
clk_data->clk_num = data->num_outputs;
clk_data->clks = kcalloc(clk_data->clk_num, sizeof(struct clk *),
GFP_KERNEL);
if (!clk_data->clks)
goto err_alloc_clks;
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:
kfree(clk_data->clks);
err_alloc_clks:
kfree(clk_data);
err_alloc:
kfree(parents);
err_parents:
iounmap(reg);
}
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 const 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 },
{}
};
static 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;
const 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 = match->data;
reg = clkgen_get_register_base(np);
if (!reg)
return;
parent_name = of_clk_get_parent_name(np, 0);
if (!parent_name)
goto err;
if (of_property_read_string_index(np, "clock-output-names",
0, &clk_name))
goto err;
clk = clk_register_divider_table(NULL, clk_name, parent_name,
CLK_GET_RATE_NOCACHE,
reg + data->offset, data->shift, 1,
0, data->table, NULL);
if (IS_ERR(clk))
goto err;
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;
err:
iounmap(reg);
}
CLK_OF_DECLARE(clkgenaprediv, "st,clkgena-prediv", st_of_clkgena_prediv_setup);
struct clkgen_mux_data {
u32 offset;
u8 shift;
u8 width;
spinlock_t *lock;
unsigned long clk_flags;
u8 mux_flags;
};
static struct clkgen_mux_data clkgen_mux_c_vcc_hd_416 = {
.offset = 0,
.shift = 0,
.width = 1,
};
static struct clkgen_mux_data clkgen_mux_f_vcc_fvdp_416 = {
.offset = 0,
.shift = 0,
.width = 1,
};
static struct clkgen_mux_data clkgen_mux_f_vcc_hva_416 = {
.offset = 0,
.shift = 0,
.width = 1,
};
static struct clkgen_mux_data clkgen_mux_f_vcc_hd_416 = {
.offset = 0,
.shift = 16,
.width = 1,
.lock = &clkgenf_lock,
};
static struct clkgen_mux_data clkgen_mux_c_vcc_sd_416 = {
.offset = 0,
.shift = 17,
.width = 1,
.lock = &clkgenf_lock,
};
static struct clkgen_mux_data stih415_a9_mux_data = {
.offset = 0,
.shift = 1,
.width = 2,
.lock = &clkgen_a9_lock,
};
static struct clkgen_mux_data stih416_a9_mux_data = {
.offset = 0,
.shift = 0,
.width = 2,
};
static struct clkgen_mux_data stih407_a9_mux_data = {
.offset = 0x1a4,
.shift = 0,
.width = 2,
.lock = &clkgen_a9_lock,
};
static const struct of_device_id mux_of_match[] = {
{
.compatible = "st,stih416-clkgenc-vcc-hd",
.data = &clkgen_mux_c_vcc_hd_416,
},
{
.compatible = "st,stih416-clkgenf-vcc-fvdp",
.data = &clkgen_mux_f_vcc_fvdp_416,
},
{
.compatible = "st,stih416-clkgenf-vcc-hva",
.data = &clkgen_mux_f_vcc_hva_416,
},
{
.compatible = "st,stih416-clkgenf-vcc-hd",
.data = &clkgen_mux_f_vcc_hd_416,
},
{
.compatible = "st,stih416-clkgenf-vcc-sd",
.data = &clkgen_mux_c_vcc_sd_416,
},
{
.compatible = "st,stih415-clkgen-a9-mux",
.data = &stih415_a9_mux_data,
},
{
.compatible = "st,stih416-clkgen-a9-mux",
.data = &stih416_a9_mux_data,
},
{
.compatible = "st,stih407-clkgen-a9-mux",
.data = &stih407_a9_mux_data,
},
{}
};
static void __init st_of_clkgen_mux_setup(struct device_node *np)
{
const struct of_device_id *match;
struct clk *clk;
void __iomem *reg;
const char **parents;
int num_parents;
const struct clkgen_mux_data *data;
match = of_match_node(mux_of_match, np);
if (!match) {
pr_err("%s: No matching data\n", __func__);
return;
}
data = match->data;
reg = of_iomap(np, 0);
if (!reg) {
pr_err("%s: Failed to get base address\n", __func__);
return;
}
parents = clkgen_mux_get_parents(np, &num_parents);
if (IS_ERR(parents)) {
pr_err("%s: Failed to get parents (%ld)\n",
__func__, PTR_ERR(parents));
goto err_parents;
}
clk = clk_register_mux(NULL, np->name, parents, num_parents,
data->clk_flags | CLK_SET_RATE_PARENT,
reg + data->offset,
data->shift, data->width, data->mux_flags,
data->lock);
if (IS_ERR(clk))
goto err;
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));
kfree(parents);
of_clk_add_provider(np, of_clk_src_simple_get, clk);
return;
err:
kfree(parents);
err_parents:
iounmap(reg);
}
CLK_OF_DECLARE(clkgen_mux, "st,clkgen-mux", st_of_clkgen_mux_setup);
#define VCC_MAX_CHANNELS 16
#define VCC_GATE_OFFSET 0x0
#define VCC_MUX_OFFSET 0x4
#define VCC_DIV_OFFSET 0x8
struct clkgen_vcc_data {
spinlock_t *lock;
unsigned long clk_flags;
};
static struct clkgen_vcc_data st_clkgenc_vcc_416 = {
.clk_flags = CLK_SET_RATE_PARENT,
};
static struct clkgen_vcc_data st_clkgenf_vcc_416 = {
.lock = &clkgenf_lock,
};
static const struct of_device_id vcc_of_match[] = {
{ .compatible = "st,stih416-clkgenc", .data = &st_clkgenc_vcc_416 },
{ .compatible = "st,stih416-clkgenf", .data = &st_clkgenf_vcc_416 },
{}
};
static void __init st_of_clkgen_vcc_setup(struct device_node *np)
{
const struct of_device_id *match;
void __iomem *reg;
const char **parents;
int num_parents, i;
struct clk_onecell_data *clk_data;
const struct clkgen_vcc_data *data;
match = of_match_node(vcc_of_match, np);
if (WARN_ON(!match))
return;
data = match->data;
reg = of_iomap(np, 0);
if (!reg)
return;
parents = clkgen_mux_get_parents(np, &num_parents);
if (IS_ERR(parents))
goto err_parents;
clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL);
if (!clk_data)
goto err_alloc;
clk_data->clk_num = VCC_MAX_CHANNELS;
clk_data->clks = kcalloc(clk_data->clk_num, sizeof(struct clk *),
GFP_KERNEL);
if (!clk_data->clks)
goto err_alloc_clks;
for (i = 0; i < clk_data->clk_num; i++) {
struct clk *clk;
const char *clk_name;
struct clk_gate *gate;
struct clk_divider *div;
struct clk_mux *mux;
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;
gate = kzalloc(sizeof(*gate), GFP_KERNEL);
if (!gate)
goto err;
div = kzalloc(sizeof(*div), GFP_KERNEL);
if (!div) {
kfree(gate);
goto err;
}
mux = kzalloc(sizeof(*mux), GFP_KERNEL);
if (!mux) {
kfree(gate);
kfree(div);
goto err;
}
gate->reg = reg + VCC_GATE_OFFSET;
gate->bit_idx = i;
gate->flags = CLK_GATE_SET_TO_DISABLE;
gate->lock = data->lock;
div->reg = reg + VCC_DIV_OFFSET;
div->shift = 2 * i;
div->width = 2;
div->flags = CLK_DIVIDER_POWER_OF_TWO |
CLK_DIVIDER_ROUND_CLOSEST;
mux->reg = reg + VCC_MUX_OFFSET;
mux->shift = 2 * i;
mux->mask = 0x3;
clk = clk_register_composite(NULL, clk_name, parents,
num_parents,
&mux->hw, &clk_mux_ops,
&div->hw, &clk_divider_ops,
&gate->hw, &clk_gate_ops,
data->clk_flags |
CLK_GET_RATE_NOCACHE);
if (IS_ERR(clk)) {
kfree(gate);
kfree(div);
kfree(mux);
goto err;
}
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));
clk_data->clks[i] = clk;
}
kfree(parents);
of_clk_add_provider(np, of_clk_src_onecell_get, clk_data);
return;
err:
for (i = 0; i < clk_data->clk_num; i++) {
struct clk_composite *composite;
if (!clk_data->clks[i])
continue;
composite = container_of(__clk_get_hw(clk_data->clks[i]),
struct clk_composite, hw);
kfree(container_of(composite->gate_hw, struct clk_gate, hw));
kfree(container_of(composite->rate_hw, struct clk_divider, hw));
kfree(container_of(composite->mux_hw, struct clk_mux, hw));
}
kfree(clk_data->clks);
err_alloc_clks:
kfree(clk_data);
err_alloc:
kfree(parents);
err_parents:
iounmap(reg);
}
CLK_OF_DECLARE(clkgen_vcc, "st,clkgen-vcc", st_of_clkgen_vcc_setup);