linux/drivers/clk/rockchip/clk.c

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/*
* Copyright (c) 2014 MundoReader S.L.
* Author: Heiko Stuebner <heiko@sntech.de>
*
* based on
*
* samsung/clk.c
* Copyright (c) 2013 Samsung Electronics Co., Ltd.
* Copyright (c) 2013 Linaro Ltd.
* Author: Thomas Abraham <thomas.ab@samsung.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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include <linux/reboot.h>
#include "clk.h"
/**
* Register a clock branch.
* Most clock branches have a form like
*
* src1 --|--\
* |M |--[GATE]-[DIV]-
* src2 --|--/
*
* sometimes without one of those components.
*/
static struct clk *rockchip_clk_register_branch(const char *name,
const char *const *parent_names, u8 num_parents, void __iomem *base,
int muxdiv_offset, u8 mux_shift, u8 mux_width, u8 mux_flags,
u8 div_shift, u8 div_width, u8 div_flags,
struct clk_div_table *div_table, int gate_offset,
u8 gate_shift, u8 gate_flags, unsigned long flags,
spinlock_t *lock)
{
struct clk *clk;
struct clk_mux *mux = NULL;
struct clk_gate *gate = NULL;
struct clk_divider *div = NULL;
const struct clk_ops *mux_ops = NULL, *div_ops = NULL,
*gate_ops = NULL;
if (num_parents > 1) {
mux = kzalloc(sizeof(*mux), GFP_KERNEL);
if (!mux)
return ERR_PTR(-ENOMEM);
mux->reg = base + muxdiv_offset;
mux->shift = mux_shift;
mux->mask = BIT(mux_width) - 1;
mux->flags = mux_flags;
mux->lock = lock;
mux_ops = (mux_flags & CLK_MUX_READ_ONLY) ? &clk_mux_ro_ops
: &clk_mux_ops;
}
if (gate_offset >= 0) {
gate = kzalloc(sizeof(*gate), GFP_KERNEL);
if (!gate)
return ERR_PTR(-ENOMEM);
gate->flags = gate_flags;
gate->reg = base + gate_offset;
gate->bit_idx = gate_shift;
gate->lock = lock;
gate_ops = &clk_gate_ops;
}
if (div_width > 0) {
div = kzalloc(sizeof(*div), GFP_KERNEL);
if (!div)
return ERR_PTR(-ENOMEM);
div->flags = div_flags;
div->reg = base + muxdiv_offset;
div->shift = div_shift;
div->width = div_width;
div->lock = lock;
div->table = div_table;
clk-divider: Fix READ_ONLY when divider > 1 Commit 79c6ab509558 (clk: divider: add CLK_DIVIDER_READ_ONLY flag) in v3.16 introduced the CLK_DIVIDER_READ_ONLY flag which caused the recalc_rate() and round_rate() clock callbacks to be omitted. However using this flag has the unfortunate side effect of causing the clock recalculation code when a clock rate change is attempted to always treat it as a pass-through clock, i.e. with a fixed divide of 1, which may not be the case. Child clock rates are then recalculated using the wrong parent rate. Therefore instead of dropping the recalc_rate() and round_rate() callbacks, alter clk_divider_bestdiv() to always report the current divider as the best divider so that it is never altered. For me the read only clock was the system clock, which divided the PLL rate by 2, from which both the UART and the SPI clocks were divided. Initial setting of the UART rate set it correctly, but when the SPI clock was set, the other child clocks were miscalculated. The UART clock was recalculated using the PLL rate as the parent rate, resulting in a UART new_rate of double what it should be, and a UART which spewed forth garbage when the rate changes were propagated. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Thomas Abraham <thomas.ab@samsung.com> Cc: Tomasz Figa <t.figa@samsung.com> Cc: Max Schwarz <max.schwarz@online.de> Cc: <stable@vger.kernel.org> # v3.16+ Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com> Signed-off-by: Michael Turquette <mturquette@linaro.org>
2014-11-14 15:32:09 +00:00
div_ops = &clk_divider_ops;
}
clk = clk_register_composite(NULL, name, parent_names, num_parents,
mux ? &mux->hw : NULL, mux_ops,
div ? &div->hw : NULL, div_ops,
gate ? &gate->hw : NULL, gate_ops,
flags);
return clk;
}
struct rockchip_clk_frac {
struct notifier_block clk_nb;
struct clk_fractional_divider div;
struct clk_gate gate;
struct clk_mux mux;
const struct clk_ops *mux_ops;
int mux_frac_idx;
bool rate_change_remuxed;
int rate_change_idx;
};
#define to_rockchip_clk_frac_nb(nb) \
container_of(nb, struct rockchip_clk_frac, clk_nb)
static int rockchip_clk_frac_notifier_cb(struct notifier_block *nb,
unsigned long event, void *data)
{
struct clk_notifier_data *ndata = data;
struct rockchip_clk_frac *frac = to_rockchip_clk_frac_nb(nb);
struct clk_mux *frac_mux = &frac->mux;
int ret = 0;
pr_debug("%s: event %lu, old_rate %lu, new_rate: %lu\n",
__func__, event, ndata->old_rate, ndata->new_rate);
if (event == PRE_RATE_CHANGE) {
frac->rate_change_idx = frac->mux_ops->get_parent(&frac_mux->hw);
if (frac->rate_change_idx != frac->mux_frac_idx) {
frac->mux_ops->set_parent(&frac_mux->hw, frac->mux_frac_idx);
frac->rate_change_remuxed = 1;
}
} else if (event == POST_RATE_CHANGE) {
/*
* The POST_RATE_CHANGE notifier runs directly after the
* divider clock is set in clk_change_rate, so we'll have
* remuxed back to the original parent before clk_change_rate
* reaches the mux itself.
*/
if (frac->rate_change_remuxed) {
frac->mux_ops->set_parent(&frac_mux->hw, frac->rate_change_idx);
frac->rate_change_remuxed = 0;
}
}
return notifier_from_errno(ret);
}
static struct clk *rockchip_clk_register_frac_branch(const char *name,
const char *const *parent_names, u8 num_parents,
void __iomem *base, int muxdiv_offset, u8 div_flags,
int gate_offset, u8 gate_shift, u8 gate_flags,
unsigned long flags, struct rockchip_clk_branch *child,
spinlock_t *lock)
{
struct rockchip_clk_frac *frac;
struct clk *clk;
struct clk_gate *gate = NULL;
struct clk_fractional_divider *div = NULL;
const struct clk_ops *div_ops = NULL, *gate_ops = NULL;
if (muxdiv_offset < 0)
return ERR_PTR(-EINVAL);
if (child && child->branch_type != branch_mux) {
pr_err("%s: fractional child clock for %s can only be a mux\n",
__func__, name);
return ERR_PTR(-EINVAL);
}
frac = kzalloc(sizeof(*frac), GFP_KERNEL);
if (!frac)
return ERR_PTR(-ENOMEM);
if (gate_offset >= 0) {
gate = &frac->gate;
gate->flags = gate_flags;
gate->reg = base + gate_offset;
gate->bit_idx = gate_shift;
gate->lock = lock;
gate_ops = &clk_gate_ops;
}
div = &frac->div;
div->flags = div_flags;
div->reg = base + muxdiv_offset;
div->mshift = 16;
div->mwidth = 16;
div->mmask = GENMASK(div->mwidth - 1, 0) << div->mshift;
div->nshift = 0;
div->nwidth = 16;
div->nmask = GENMASK(div->nwidth - 1, 0) << div->nshift;
div->lock = lock;
div_ops = &clk_fractional_divider_ops;
clk = clk_register_composite(NULL, name, parent_names, num_parents,
NULL, NULL,
&div->hw, div_ops,
gate ? &gate->hw : NULL, gate_ops,
flags | CLK_SET_RATE_UNGATE);
if (IS_ERR(clk)) {
kfree(frac);
return clk;
}
if (child) {
struct clk_mux *frac_mux = &frac->mux;
struct clk_init_data init;
struct clk *mux_clk;
int i, ret;
frac->mux_frac_idx = -1;
for (i = 0; i < child->num_parents; i++) {
if (!strcmp(name, child->parent_names[i])) {
pr_debug("%s: found fractional parent in mux at pos %d\n",
__func__, i);
frac->mux_frac_idx = i;
break;
}
}
frac->mux_ops = &clk_mux_ops;
frac->clk_nb.notifier_call = rockchip_clk_frac_notifier_cb;
frac_mux->reg = base + child->muxdiv_offset;
frac_mux->shift = child->mux_shift;
frac_mux->mask = BIT(child->mux_width) - 1;
frac_mux->flags = child->mux_flags;
frac_mux->lock = lock;
frac_mux->hw.init = &init;
init.name = child->name;
init.flags = child->flags | CLK_SET_RATE_PARENT;
init.ops = frac->mux_ops;
init.parent_names = child->parent_names;
init.num_parents = child->num_parents;
mux_clk = clk_register(NULL, &frac_mux->hw);
if (IS_ERR(mux_clk))
return clk;
rockchip_clk_add_lookup(mux_clk, child->id);
/* notifier on the fraction divider to catch rate changes */
if (frac->mux_frac_idx >= 0) {
ret = clk_notifier_register(clk, &frac->clk_nb);
if (ret)
pr_err("%s: failed to register clock notifier for %s\n",
__func__, name);
} else {
pr_warn("%s: could not find %s as parent of %s, rate changes may not work\n",
__func__, name, child->name);
}
}
return clk;
}
static DEFINE_SPINLOCK(clk_lock);
static struct clk **clk_table;
static void __iomem *reg_base;
static struct clk_onecell_data clk_data;
static struct device_node *cru_node;
static struct regmap *grf;
void __init rockchip_clk_init(struct device_node *np, void __iomem *base,
unsigned long nr_clks)
{
reg_base = base;
cru_node = np;
grf = ERR_PTR(-EPROBE_DEFER);
clk_table = kcalloc(nr_clks, sizeof(struct clk *), GFP_KERNEL);
if (!clk_table)
pr_err("%s: could not allocate clock lookup table\n", __func__);
clk_data.clks = clk_table;
clk_data.clk_num = nr_clks;
of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
}
struct regmap *rockchip_clk_get_grf(void)
{
if (IS_ERR(grf))
grf = syscon_regmap_lookup_by_phandle(cru_node, "rockchip,grf");
return grf;
}
void rockchip_clk_add_lookup(struct clk *clk, unsigned int id)
{
if (clk_table && id)
clk_table[id] = clk;
}
void __init rockchip_clk_register_plls(struct rockchip_pll_clock *list,
unsigned int nr_pll, int grf_lock_offset)
{
struct clk *clk;
int idx;
for (idx = 0; idx < nr_pll; idx++, list++) {
clk = rockchip_clk_register_pll(list->type, list->name,
list->parent_names, list->num_parents,
reg_base, list->con_offset, grf_lock_offset,
list->lock_shift, list->mode_offset,
list->mode_shift, list->rate_table,
list->pll_flags, &clk_lock);
if (IS_ERR(clk)) {
pr_err("%s: failed to register clock %s\n", __func__,
list->name);
continue;
}
rockchip_clk_add_lookup(clk, list->id);
}
}
void __init rockchip_clk_register_branches(
struct rockchip_clk_branch *list,
unsigned int nr_clk)
{
struct clk *clk = NULL;
unsigned int idx;
unsigned long flags;
for (idx = 0; idx < nr_clk; idx++, list++) {
flags = list->flags;
/* catch simple muxes */
switch (list->branch_type) {
case branch_mux:
clk = clk_register_mux(NULL, list->name,
list->parent_names, list->num_parents,
flags, reg_base + list->muxdiv_offset,
list->mux_shift, list->mux_width,
list->mux_flags, &clk_lock);
break;
case branch_divider:
if (list->div_table)
clk = clk_register_divider_table(NULL,
list->name, list->parent_names[0],
flags, reg_base + list->muxdiv_offset,
list->div_shift, list->div_width,
list->div_flags, list->div_table,
&clk_lock);
else
clk = clk_register_divider(NULL, list->name,
list->parent_names[0], flags,
reg_base + list->muxdiv_offset,
list->div_shift, list->div_width,
list->div_flags, &clk_lock);
break;
case branch_fraction_divider:
clk = rockchip_clk_register_frac_branch(list->name,
list->parent_names, list->num_parents,
reg_base, list->muxdiv_offset, list->div_flags,
list->gate_offset, list->gate_shift,
list->gate_flags, flags, list->child,
&clk_lock);
break;
case branch_gate:
flags |= CLK_SET_RATE_PARENT;
clk = clk_register_gate(NULL, list->name,
list->parent_names[0], flags,
reg_base + list->gate_offset,
list->gate_shift, list->gate_flags, &clk_lock);
break;
case branch_composite:
clk = rockchip_clk_register_branch(list->name,
list->parent_names, list->num_parents,
reg_base, list->muxdiv_offset, list->mux_shift,
list->mux_width, list->mux_flags,
list->div_shift, list->div_width,
list->div_flags, list->div_table,
list->gate_offset, list->gate_shift,
list->gate_flags, flags, &clk_lock);
break;
case branch_mmc:
clk = rockchip_clk_register_mmc(
list->name,
list->parent_names, list->num_parents,
reg_base + list->muxdiv_offset,
list->div_shift
);
break;
case branch_inverter:
clk = rockchip_clk_register_inverter(
list->name, list->parent_names,
list->num_parents,
reg_base + list->muxdiv_offset,
list->div_shift, list->div_flags, &clk_lock);
break;
}
/* none of the cases above matched */
if (!clk) {
pr_err("%s: unknown clock type %d\n",
__func__, list->branch_type);
continue;
}
if (IS_ERR(clk)) {
pr_err("%s: failed to register clock %s: %ld\n",
__func__, list->name, PTR_ERR(clk));
continue;
}
rockchip_clk_add_lookup(clk, list->id);
}
}
void __init rockchip_clk_register_armclk(unsigned int lookup_id,
const char *name, const char *const *parent_names,
u8 num_parents,
const struct rockchip_cpuclk_reg_data *reg_data,
const struct rockchip_cpuclk_rate_table *rates,
int nrates)
{
struct clk *clk;
clk = rockchip_clk_register_cpuclk(name, parent_names, num_parents,
reg_data, rates, nrates, reg_base,
&clk_lock);
if (IS_ERR(clk)) {
pr_err("%s: failed to register clock %s: %ld\n",
__func__, name, PTR_ERR(clk));
return;
}
rockchip_clk_add_lookup(clk, lookup_id);
}
void __init rockchip_clk_protect_critical(const char *const clocks[],
int nclocks)
{
int i;
/* Protect the clocks that needs to stay on */
for (i = 0; i < nclocks; i++) {
struct clk *clk = __clk_lookup(clocks[i]);
if (clk)
clk_prepare_enable(clk);
}
}
static unsigned int reg_restart;
static void (*cb_restart)(void);
static int rockchip_restart_notify(struct notifier_block *this,
unsigned long mode, void *cmd)
{
if (cb_restart)
cb_restart();
writel(0xfdb9, reg_base + reg_restart);
return NOTIFY_DONE;
}
static struct notifier_block rockchip_restart_handler = {
.notifier_call = rockchip_restart_notify,
.priority = 128,
};
void __init rockchip_register_restart_notifier(unsigned int reg, void (*cb)(void))
{
int ret;
reg_restart = reg;
cb_restart = cb;
ret = register_restart_handler(&rockchip_restart_handler);
if (ret)
pr_err("%s: cannot register restart handler, %d\n",
__func__, ret);
}