clk: ux500: Add support for sysctrl clocks

The abx500 sysctrl clocks are using the ab8500 sysctrl driver to
modify the clock hardware. Sysctrl clocks are represented by a
ab8500 sysctrl register and with a corresponding bitmask.

The sysctrl clocks are slow path clocks, which means clk_prepare
and clk_unprepare will be used to gate|ungate these clocks.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
This commit is contained in:
Ulf Hansson 2013-04-03 14:26:57 +02:00 committed by Mike Turquette
parent 4cb24e68a5
commit 5b82d03b74
3 changed files with 251 additions and 0 deletions

View File

@ -5,6 +5,7 @@
# Clock types
obj-y += clk-prcc.o
obj-y += clk-prcmu.o
obj-y += clk-sysctrl.o
# Clock definitions
obj-y += u8500_clk.o

View File

@ -0,0 +1,221 @@
/*
* Sysctrl clock implementation for ux500 platform.
*
* Copyright (C) 2013 ST-Ericsson SA
* Author: Ulf Hansson <ulf.hansson@linaro.org>
*
* License terms: GNU General Public License (GPL) version 2
*/
#include <linux/clk-provider.h>
#include <linux/mfd/abx500/ab8500-sysctrl.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/err.h>
#include "clk.h"
#define SYSCTRL_MAX_NUM_PARENTS 4
#define to_clk_sysctrl(_hw) container_of(_hw, struct clk_sysctrl, hw)
struct clk_sysctrl {
struct clk_hw hw;
struct device *dev;
u8 parent_index;
u16 reg_sel[SYSCTRL_MAX_NUM_PARENTS];
u8 reg_mask[SYSCTRL_MAX_NUM_PARENTS];
u8 reg_bits[SYSCTRL_MAX_NUM_PARENTS];
unsigned long rate;
unsigned long enable_delay_us;
};
/* Sysctrl clock operations. */
static int clk_sysctrl_prepare(struct clk_hw *hw)
{
int ret;
struct clk_sysctrl *clk = to_clk_sysctrl(hw);
ret = ab8500_sysctrl_write(clk->reg_sel[0], clk->reg_mask[0],
clk->reg_bits[0]);
if (!ret && clk->enable_delay_us)
usleep_range(clk->enable_delay_us, clk->enable_delay_us);
return ret;
}
static void clk_sysctrl_unprepare(struct clk_hw *hw)
{
struct clk_sysctrl *clk = to_clk_sysctrl(hw);
if (ab8500_sysctrl_clear(clk->reg_sel[0], clk->reg_mask[0]))
dev_err(clk->dev, "clk_sysctrl: %s fail to clear %s.\n",
__func__, __clk_get_name(hw->clk));
}
static unsigned long clk_sysctrl_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_sysctrl *clk = to_clk_sysctrl(hw);
return clk->rate;
}
static int clk_sysctrl_set_parent(struct clk_hw *hw, u8 index)
{
struct clk_sysctrl *clk = to_clk_sysctrl(hw);
u8 old_index = clk->parent_index;
int ret = 0;
if (clk->reg_sel[old_index]) {
ret = ab8500_sysctrl_clear(clk->reg_sel[old_index],
clk->reg_mask[old_index]);
if (ret)
return ret;
}
if (clk->reg_sel[index]) {
ret = ab8500_sysctrl_write(clk->reg_sel[index],
clk->reg_mask[index],
clk->reg_bits[index]);
if (ret) {
if (clk->reg_sel[old_index])
ab8500_sysctrl_write(clk->reg_sel[old_index],
clk->reg_mask[old_index],
clk->reg_bits[old_index]);
return ret;
}
}
clk->parent_index = index;
return ret;
}
static u8 clk_sysctrl_get_parent(struct clk_hw *hw)
{
struct clk_sysctrl *clk = to_clk_sysctrl(hw);
return clk->parent_index;
}
static struct clk_ops clk_sysctrl_gate_ops = {
.prepare = clk_sysctrl_prepare,
.unprepare = clk_sysctrl_unprepare,
};
static struct clk_ops clk_sysctrl_gate_fixed_rate_ops = {
.prepare = clk_sysctrl_prepare,
.unprepare = clk_sysctrl_unprepare,
.recalc_rate = clk_sysctrl_recalc_rate,
};
static struct clk_ops clk_sysctrl_set_parent_ops = {
.set_parent = clk_sysctrl_set_parent,
.get_parent = clk_sysctrl_get_parent,
};
static struct clk *clk_reg_sysctrl(struct device *dev,
const char *name,
const char **parent_names,
u8 num_parents,
u16 *reg_sel,
u8 *reg_mask,
u8 *reg_bits,
unsigned long rate,
unsigned long enable_delay_us,
unsigned long flags,
struct clk_ops *clk_sysctrl_ops)
{
struct clk_sysctrl *clk;
struct clk_init_data clk_sysctrl_init;
struct clk *clk_reg;
int i;
if (!dev)
return ERR_PTR(-EINVAL);
if (!name || (num_parents > SYSCTRL_MAX_NUM_PARENTS)) {
dev_err(dev, "clk_sysctrl: invalid arguments passed\n");
return ERR_PTR(-EINVAL);
}
clk = devm_kzalloc(dev, sizeof(struct clk_sysctrl), GFP_KERNEL);
if (!clk) {
dev_err(dev, "clk_sysctrl: could not allocate clk\n");
return ERR_PTR(-ENOMEM);
}
for (i = 0; i < num_parents; i++) {
clk->reg_sel[i] = reg_sel[i];
clk->reg_bits[i] = reg_bits[i];
clk->reg_mask[i] = reg_mask[i];
}
clk->parent_index = 0;
clk->rate = rate;
clk->enable_delay_us = enable_delay_us;
clk->dev = dev;
clk_sysctrl_init.name = name;
clk_sysctrl_init.ops = clk_sysctrl_ops;
clk_sysctrl_init.flags = flags;
clk_sysctrl_init.parent_names = parent_names;
clk_sysctrl_init.num_parents = num_parents;
clk->hw.init = &clk_sysctrl_init;
clk_reg = devm_clk_register(clk->dev, &clk->hw);
if (IS_ERR(clk_reg))
dev_err(dev, "clk_sysctrl: clk_register failed\n");
return clk_reg;
}
struct clk *clk_reg_sysctrl_gate(struct device *dev,
const char *name,
const char *parent_name,
u16 reg_sel,
u8 reg_mask,
u8 reg_bits,
unsigned long enable_delay_us,
unsigned long flags)
{
const char **parent_names = (parent_name ? &parent_name : NULL);
u8 num_parents = (parent_name ? 1 : 0);
return clk_reg_sysctrl(dev, name, parent_names, num_parents,
&reg_sel, &reg_mask, &reg_bits, 0, enable_delay_us,
flags, &clk_sysctrl_gate_ops);
}
struct clk *clk_reg_sysctrl_gate_fixed_rate(struct device *dev,
const char *name,
const char *parent_name,
u16 reg_sel,
u8 reg_mask,
u8 reg_bits,
unsigned long rate,
unsigned long enable_delay_us,
unsigned long flags)
{
const char **parent_names = (parent_name ? &parent_name : NULL);
u8 num_parents = (parent_name ? 1 : 0);
return clk_reg_sysctrl(dev, name, parent_names, num_parents,
&reg_sel, &reg_mask, &reg_bits,
rate, enable_delay_us, flags,
&clk_sysctrl_gate_fixed_rate_ops);
}
struct clk *clk_reg_sysctrl_set_parent(struct device *dev,
const char *name,
const char **parent_names,
u8 num_parents,
u16 *reg_sel,
u8 *reg_mask,
u8 *reg_bits,
unsigned long flags)
{
return clk_reg_sysctrl(dev, name, parent_names, num_parents,
reg_sel, reg_mask, reg_bits, 0, 0, flags,
&clk_sysctrl_set_parent_ops);
}

View File

@ -11,6 +11,7 @@
#define __UX500_CLK_H
#include <linux/clk.h>
#include <linux/device.h>
struct clk *clk_reg_prcc_pclk(const char *name,
const char *parent_name,
@ -57,4 +58,32 @@ struct clk *clk_reg_prcmu_opp_volt_scalable(const char *name,
unsigned long rate,
unsigned long flags);
struct clk *clk_reg_sysctrl_gate(struct device *dev,
const char *name,
const char *parent_name,
u16 reg_sel,
u8 reg_mask,
u8 reg_bits,
unsigned long enable_delay_us,
unsigned long flags);
struct clk *clk_reg_sysctrl_gate_fixed_rate(struct device *dev,
const char *name,
const char *parent_name,
u16 reg_sel,
u8 reg_mask,
u8 reg_bits,
unsigned long rate,
unsigned long enable_delay_us,
unsigned long flags);
struct clk *clk_reg_sysctrl_set_parent(struct device *dev,
const char *name,
const char **parent_names,
u8 num_parents,
u16 *reg_sel,
u8 *reg_mask,
u8 *reg_bits,
unsigned long flags);
#endif /* __UX500_CLK_H */