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linux-next/drivers/clk/clk-cs2000-cp.c
Arnd Bergmann a21b85944c clk: cs2000: mark resume function as __maybe_unused 
When power management is disabled, we get a harmless warning:

drivers/clk/clk-cs2000-cp.c:544:12: error: 'cs2000_resume' defined but not used [-Werror=unused-function]

Marking the function as __maybe_unused lets the compiler silently
drop it instead.

Fixes: eade4ccdb0 ("clk: cs2000: set pm_ops in hibernate-compatible way")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2018-04-16 09:07:22 -07:00

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/*
* CS2000 -- CIRRUS LOGIC Fractional-N Clock Synthesizer & Clock Multiplier
*
* Copyright (C) 2015 Renesas Electronics Corporation
* Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/clk-provider.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/i2c.h>
#include <linux/of_device.h>
#include <linux/module.h>
#define CH_MAX 4
#define RATIO_REG_SIZE 4
#define DEVICE_ID 0x1
#define DEVICE_CTRL 0x2
#define DEVICE_CFG1 0x3
#define DEVICE_CFG2 0x4
#define GLOBAL_CFG 0x5
#define Ratio_Add(x, nth) (6 + (x * 4) + (nth))
#define Ratio_Val(x, nth) ((x >> (24 - (8 * nth))) & 0xFF)
#define Val_Ratio(x, nth) ((x & 0xFF) << (24 - (8 * nth)))
#define FUNC_CFG1 0x16
#define FUNC_CFG2 0x17
/* DEVICE_ID */
#define REVISION_MASK (0x7)
#define REVISION_B2_B3 (0x4)
#define REVISION_C1 (0x6)
/* DEVICE_CTRL */
#define PLL_UNLOCK (1 << 7)
#define AUXOUTDIS (1 << 1)
#define CLKOUTDIS (1 << 0)
/* DEVICE_CFG1 */
#define RSEL(x) (((x) & 0x3) << 3)
#define RSEL_MASK RSEL(0x3)
#define ENDEV1 (0x1)
/* DEVICE_CFG2 */
#define AUTORMOD (1 << 3)
#define LOCKCLK(x) (((x) & 0x3) << 1)
#define LOCKCLK_MASK LOCKCLK(0x3)
#define FRACNSRC_MASK (1 << 0)
#define FRACNSRC_STATIC (0 << 0)
#define FRACNSRC_DYNAMIC (1 << 1)
/* GLOBAL_CFG */
#define ENDEV2 (0x1)
/* FUNC_CFG1 */
#define CLKSKIPEN (1 << 7)
#define REFCLKDIV(x) (((x) & 0x3) << 3)
#define REFCLKDIV_MASK REFCLKDIV(0x3)
/* FUNC_CFG2 */
#define LFRATIO_MASK (1 << 3)
#define LFRATIO_20_12 (0 << 3)
#define LFRATIO_12_20 (1 << 3)
#define CH_SIZE_ERR(ch) ((ch < 0) || (ch >= CH_MAX))
#define hw_to_priv(_hw) container_of(_hw, struct cs2000_priv, hw)
#define priv_to_client(priv) (priv->client)
#define priv_to_dev(priv) (&(priv_to_client(priv)->dev))
#define CLK_IN 0
#define REF_CLK 1
#define CLK_MAX 2
struct cs2000_priv {
struct clk_hw hw;
struct i2c_client *client;
struct clk *clk_in;
struct clk *ref_clk;
/* suspend/resume */
unsigned long saved_rate;
unsigned long saved_parent_rate;
};
static const struct of_device_id cs2000_of_match[] = {
{ .compatible = "cirrus,cs2000-cp", },
{},
};
MODULE_DEVICE_TABLE(of, cs2000_of_match);
static const struct i2c_device_id cs2000_id[] = {
{ "cs2000-cp", },
{}
};
MODULE_DEVICE_TABLE(i2c, cs2000_id);
#define cs2000_read(priv, addr) \
i2c_smbus_read_byte_data(priv_to_client(priv), addr)
#define cs2000_write(priv, addr, val) \
i2c_smbus_write_byte_data(priv_to_client(priv), addr, val)
static int cs2000_bset(struct cs2000_priv *priv, u8 addr, u8 mask, u8 val)
{
s32 data;
data = cs2000_read(priv, addr);
if (data < 0)
return data;
data &= ~mask;
data |= (val & mask);
return cs2000_write(priv, addr, data);
}
static int cs2000_enable_dev_config(struct cs2000_priv *priv, bool enable)
{
int ret;
ret = cs2000_bset(priv, DEVICE_CFG1, ENDEV1,
enable ? ENDEV1 : 0);
if (ret < 0)
return ret;
ret = cs2000_bset(priv, GLOBAL_CFG, ENDEV2,
enable ? ENDEV2 : 0);
if (ret < 0)
return ret;
ret = cs2000_bset(priv, FUNC_CFG1, CLKSKIPEN,
enable ? CLKSKIPEN : 0);
if (ret < 0)
return ret;
/* FIXME: for Static ratio mode */
ret = cs2000_bset(priv, FUNC_CFG2, LFRATIO_MASK,
LFRATIO_12_20);
if (ret < 0)
return ret;
return 0;
}
static int cs2000_clk_in_bound_rate(struct cs2000_priv *priv,
u32 rate_in)
{
u32 val;
if (rate_in >= 32000000 && rate_in < 56000000)
val = 0x0;
else if (rate_in >= 16000000 && rate_in < 28000000)
val = 0x1;
else if (rate_in >= 8000000 && rate_in < 14000000)
val = 0x2;
else
return -EINVAL;
return cs2000_bset(priv, FUNC_CFG1,
REFCLKDIV_MASK,
REFCLKDIV(val));
}
static int cs2000_wait_pll_lock(struct cs2000_priv *priv)
{
struct device *dev = priv_to_dev(priv);
s32 val;
unsigned int i;
for (i = 0; i < 256; i++) {
val = cs2000_read(priv, DEVICE_CTRL);
if (val < 0)
return val;
if (!(val & PLL_UNLOCK))
return 0;
udelay(1);
}
dev_err(dev, "pll lock failed\n");
return -ETIMEDOUT;
}
static int cs2000_clk_out_enable(struct cs2000_priv *priv, bool enable)
{
/* enable both AUX_OUT, CLK_OUT */
return cs2000_bset(priv, DEVICE_CTRL,
(AUXOUTDIS | CLKOUTDIS),
enable ? 0 :
(AUXOUTDIS | CLKOUTDIS));
}
static u32 cs2000_rate_to_ratio(u32 rate_in, u32 rate_out)
{
u64 ratio;
/*
* ratio = rate_out / rate_in * 2^20
*
* To avoid over flow, rate_out is u64.
* The result should be u32.
*/
ratio = (u64)rate_out << 20;
do_div(ratio, rate_in);
return ratio;
}
static unsigned long cs2000_ratio_to_rate(u32 ratio, u32 rate_in)
{
u64 rate_out;
/*
* ratio = rate_out / rate_in * 2^20
*
* To avoid over flow, rate_out is u64.
* The result should be u32 or unsigned long.
*/
rate_out = (u64)ratio * rate_in;
return rate_out >> 20;
}
static int cs2000_ratio_set(struct cs2000_priv *priv,
int ch, u32 rate_in, u32 rate_out)
{
u32 val;
unsigned int i;
int ret;
if (CH_SIZE_ERR(ch))
return -EINVAL;
val = cs2000_rate_to_ratio(rate_in, rate_out);
for (i = 0; i < RATIO_REG_SIZE; i++) {
ret = cs2000_write(priv,
Ratio_Add(ch, i),
Ratio_Val(val, i));
if (ret < 0)
return ret;
}
return 0;
}
static u32 cs2000_ratio_get(struct cs2000_priv *priv, int ch)
{
s32 tmp;
u32 val;
unsigned int i;
val = 0;
for (i = 0; i < RATIO_REG_SIZE; i++) {
tmp = cs2000_read(priv, Ratio_Add(ch, i));
if (tmp < 0)
return 0;
val |= Val_Ratio(tmp, i);
}
return val;
}
static int cs2000_ratio_select(struct cs2000_priv *priv, int ch)
{
int ret;
if (CH_SIZE_ERR(ch))
return -EINVAL;
/*
* FIXME
*
* this driver supports static ratio mode only at this point.
*/
ret = cs2000_bset(priv, DEVICE_CFG1, RSEL_MASK, RSEL(ch));
if (ret < 0)
return ret;
ret = cs2000_bset(priv, DEVICE_CFG2,
(AUTORMOD | LOCKCLK_MASK | FRACNSRC_MASK),
(LOCKCLK(ch) | FRACNSRC_STATIC));
if (ret < 0)
return ret;
return 0;
}
static unsigned long cs2000_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct cs2000_priv *priv = hw_to_priv(hw);
int ch = 0; /* it uses ch0 only at this point */
u32 ratio;
ratio = cs2000_ratio_get(priv, ch);
return cs2000_ratio_to_rate(ratio, parent_rate);
}
static long cs2000_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
u32 ratio;
ratio = cs2000_rate_to_ratio(*parent_rate, rate);
return cs2000_ratio_to_rate(ratio, *parent_rate);
}
static int __cs2000_set_rate(struct cs2000_priv *priv, int ch,
unsigned long rate, unsigned long parent_rate)
{
int ret;
ret = cs2000_clk_in_bound_rate(priv, parent_rate);
if (ret < 0)
return ret;
ret = cs2000_ratio_set(priv, ch, parent_rate, rate);
if (ret < 0)
return ret;
ret = cs2000_ratio_select(priv, ch);
if (ret < 0)
return ret;
priv->saved_rate = rate;
priv->saved_parent_rate = parent_rate;
return 0;
}
static int cs2000_set_rate(struct clk_hw *hw,
unsigned long rate, unsigned long parent_rate)
{
struct cs2000_priv *priv = hw_to_priv(hw);
int ch = 0; /* it uses ch0 only at this point */
return __cs2000_set_rate(priv, ch, rate, parent_rate);
}
static int cs2000_set_saved_rate(struct cs2000_priv *priv)
{
int ch = 0; /* it uses ch0 only at this point */
return __cs2000_set_rate(priv, ch,
priv->saved_rate,
priv->saved_parent_rate);
}
static int cs2000_enable(struct clk_hw *hw)
{
struct cs2000_priv *priv = hw_to_priv(hw);
int ret;
ret = cs2000_enable_dev_config(priv, true);
if (ret < 0)
return ret;
ret = cs2000_clk_out_enable(priv, true);
if (ret < 0)
return ret;
ret = cs2000_wait_pll_lock(priv);
if (ret < 0)
return ret;
return ret;
}
static void cs2000_disable(struct clk_hw *hw)
{
struct cs2000_priv *priv = hw_to_priv(hw);
cs2000_enable_dev_config(priv, false);
cs2000_clk_out_enable(priv, false);
}
static u8 cs2000_get_parent(struct clk_hw *hw)
{
/* always return REF_CLK */
return REF_CLK;
}
static const struct clk_ops cs2000_ops = {
.get_parent = cs2000_get_parent,
.recalc_rate = cs2000_recalc_rate,
.round_rate = cs2000_round_rate,
.set_rate = cs2000_set_rate,
.prepare = cs2000_enable,
.unprepare = cs2000_disable,
};
static int cs2000_clk_get(struct cs2000_priv *priv)
{
struct device *dev = priv_to_dev(priv);
struct clk *clk_in, *ref_clk;
clk_in = devm_clk_get(dev, "clk_in");
/* not yet provided */
if (IS_ERR(clk_in))
return -EPROBE_DEFER;
ref_clk = devm_clk_get(dev, "ref_clk");
/* not yet provided */
if (IS_ERR(ref_clk))
return -EPROBE_DEFER;
priv->clk_in = clk_in;
priv->ref_clk = ref_clk;
return 0;
}
static int cs2000_clk_register(struct cs2000_priv *priv)
{
struct device *dev = priv_to_dev(priv);
struct device_node *np = dev->of_node;
struct clk_init_data init;
const char *name = np->name;
static const char *parent_names[CLK_MAX];
int ch = 0; /* it uses ch0 only at this point */
int rate;
int ret;
of_property_read_string(np, "clock-output-names", &name);
/*
* set default rate as 1/1.
* otherwise .set_rate which setup ratio
* is never called if user requests 1/1 rate
*/
rate = clk_get_rate(priv->ref_clk);
ret = __cs2000_set_rate(priv, ch, rate, rate);
if (ret < 0)
return ret;
parent_names[CLK_IN] = __clk_get_name(priv->clk_in);
parent_names[REF_CLK] = __clk_get_name(priv->ref_clk);
init.name = name;
init.ops = &cs2000_ops;
init.flags = CLK_SET_RATE_GATE;
init.parent_names = parent_names;
init.num_parents = ARRAY_SIZE(parent_names);
priv->hw.init = &init;
ret = clk_hw_register(dev, &priv->hw);
if (ret)
return ret;
ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, &priv->hw);
if (ret < 0) {
clk_hw_unregister(&priv->hw);
return ret;
}
return 0;
}
static int cs2000_version_print(struct cs2000_priv *priv)
{
struct device *dev = priv_to_dev(priv);
s32 val;
const char *revision;
val = cs2000_read(priv, DEVICE_ID);
if (val < 0)
return val;
/* CS2000 should be 0x0 */
if (val >> 3)
return -EIO;
switch (val & REVISION_MASK) {
case REVISION_B2_B3:
revision = "B2 / B3";
break;
case REVISION_C1:
revision = "C1";
break;
default:
return -EIO;
}
dev_info(dev, "revision - %s\n", revision);
return 0;
}
static int cs2000_remove(struct i2c_client *client)
{
struct cs2000_priv *priv = i2c_get_clientdata(client);
struct device *dev = priv_to_dev(priv);
struct device_node *np = dev->of_node;
of_clk_del_provider(np);
clk_hw_unregister(&priv->hw);
return 0;
}
static int cs2000_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct cs2000_priv *priv;
struct device *dev = &client->dev;
int ret;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->client = client;
i2c_set_clientdata(client, priv);
ret = cs2000_clk_get(priv);
if (ret < 0)
return ret;
ret = cs2000_clk_register(priv);
if (ret < 0)
return ret;
ret = cs2000_version_print(priv);
if (ret < 0)
goto probe_err;
return 0;
probe_err:
cs2000_remove(client);
return ret;
}
static int __maybe_unused cs2000_resume(struct device *dev)
{
struct cs2000_priv *priv = dev_get_drvdata(dev);
return cs2000_set_saved_rate(priv);
}
static const struct dev_pm_ops cs2000_pm_ops = {
SET_LATE_SYSTEM_SLEEP_PM_OPS(NULL, cs2000_resume)
};
static struct i2c_driver cs2000_driver = {
.driver = {
.name = "cs2000-cp",
.pm = &cs2000_pm_ops,
.of_match_table = cs2000_of_match,
},
.probe = cs2000_probe,
.remove = cs2000_remove,
.id_table = cs2000_id,
};
module_i2c_driver(cs2000_driver);
MODULE_DESCRIPTION("CS2000-CP driver");
MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");
MODULE_LICENSE("GPL v2");
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