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linux/drivers/clk/clk-max9485.c
Stephen Kitt 55349aedb5 clk: max9485: use simple i2c probe function 
The i2c probe function here doesn't use the id information provided in
its second argument, so the single-parameter i2c probe function
("probe_new") can be used instead.

This avoids scanning the identifier tables during probes.

Signed-off-by: Stephen Kitt <steve@sk2.org>
Link: https://lore.kernel.org/r/20220407151831.2371706-5-steve@sk2.org
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2022-04-22 19:28:08 -07:00

387 lines
9.9 KiB
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// SPDX-License-Identifier: GPL-2.0
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/regulator/consumer.h>
#include <dt-bindings/clock/maxim,max9485.h>
#define MAX9485_NUM_CLKS 4
/* This chip has only one register of 8 bit width. */
#define MAX9485_FS_12KHZ (0 << 0)
#define MAX9485_FS_32KHZ (1 << 0)
#define MAX9485_FS_44_1KHZ (2 << 0)
#define MAX9485_FS_48KHZ (3 << 0)
#define MAX9485_SCALE_256 (0 << 2)
#define MAX9485_SCALE_384 (1 << 2)
#define MAX9485_SCALE_768 (2 << 2)
#define MAX9485_DOUBLE BIT(4)
#define MAX9485_CLKOUT1_ENABLE BIT(5)
#define MAX9485_CLKOUT2_ENABLE BIT(6)
#define MAX9485_MCLK_ENABLE BIT(7)
#define MAX9485_FREQ_MASK 0x1f
struct max9485_rate {
unsigned long out;
u8 reg_value;
};
/*
* Ordered by frequency. For frequency the hardware can generate with
* multiple settings, the one with lowest jitter is listed first.
*/
static const struct max9485_rate max9485_rates[] = {
{ 3072000, MAX9485_FS_12KHZ | MAX9485_SCALE_256 },
{ 4608000, MAX9485_FS_12KHZ | MAX9485_SCALE_384 },
{ 8192000, MAX9485_FS_32KHZ | MAX9485_SCALE_256 },
{ 9126000, MAX9485_FS_12KHZ | MAX9485_SCALE_768 },
{ 11289600, MAX9485_FS_44_1KHZ | MAX9485_SCALE_256 },
{ 12288000, MAX9485_FS_48KHZ | MAX9485_SCALE_256 },
{ 12288000, MAX9485_FS_32KHZ | MAX9485_SCALE_384 },
{ 16384000, MAX9485_FS_32KHZ | MAX9485_SCALE_256 | MAX9485_DOUBLE },
{ 16934400, MAX9485_FS_44_1KHZ | MAX9485_SCALE_384 },
{ 18384000, MAX9485_FS_48KHZ | MAX9485_SCALE_384 },
{ 22579200, MAX9485_FS_44_1KHZ | MAX9485_SCALE_256 | MAX9485_DOUBLE },
{ 24576000, MAX9485_FS_48KHZ | MAX9485_SCALE_256 | MAX9485_DOUBLE },
{ 24576000, MAX9485_FS_32KHZ | MAX9485_SCALE_384 | MAX9485_DOUBLE },
{ 24576000, MAX9485_FS_32KHZ | MAX9485_SCALE_768 },
{ 33868800, MAX9485_FS_44_1KHZ | MAX9485_SCALE_384 | MAX9485_DOUBLE },
{ 33868800, MAX9485_FS_44_1KHZ | MAX9485_SCALE_768 },
{ 36864000, MAX9485_FS_48KHZ | MAX9485_SCALE_384 | MAX9485_DOUBLE },
{ 36864000, MAX9485_FS_48KHZ | MAX9485_SCALE_768 },
{ 49152000, MAX9485_FS_32KHZ | MAX9485_SCALE_768 | MAX9485_DOUBLE },
{ 67737600, MAX9485_FS_44_1KHZ | MAX9485_SCALE_768 | MAX9485_DOUBLE },
{ 73728000, MAX9485_FS_48KHZ | MAX9485_SCALE_768 | MAX9485_DOUBLE },
{ } /* sentinel */
};
struct max9485_driver_data;
struct max9485_clk_hw {
struct clk_hw hw;
struct clk_init_data init;
u8 enable_bit;
struct max9485_driver_data *drvdata;
};
struct max9485_driver_data {
struct clk *xclk;
struct i2c_client *client;
u8 reg_value;
struct regulator *supply;
struct gpio_desc *reset_gpio;
struct max9485_clk_hw hw[MAX9485_NUM_CLKS];
};
static inline struct max9485_clk_hw *to_max9485_clk(struct clk_hw *hw)
{
return container_of(hw, struct max9485_clk_hw, hw);
}
static int max9485_update_bits(struct max9485_driver_data *drvdata,
u8 mask, u8 value)
{
int ret;
drvdata->reg_value &= ~mask;
drvdata->reg_value |= value;
dev_dbg(&drvdata->client->dev,
"updating mask 0x%02x value 0x%02x -> 0x%02x\n",
mask, value, drvdata->reg_value);
ret = i2c_master_send(drvdata->client,
&drvdata->reg_value,
sizeof(drvdata->reg_value));
return ret < 0 ? ret : 0;
}
static int max9485_clk_prepare(struct clk_hw *hw)
{
struct max9485_clk_hw *clk_hw = to_max9485_clk(hw);
return max9485_update_bits(clk_hw->drvdata,
clk_hw->enable_bit,
clk_hw->enable_bit);
}
static void max9485_clk_unprepare(struct clk_hw *hw)
{
struct max9485_clk_hw *clk_hw = to_max9485_clk(hw);
max9485_update_bits(clk_hw->drvdata, clk_hw->enable_bit, 0);
}
/*
* CLKOUT - configurable clock output
*/
static int max9485_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct max9485_clk_hw *clk_hw = to_max9485_clk(hw);
const struct max9485_rate *entry;
for (entry = max9485_rates; entry->out != 0; entry++)
if (entry->out == rate)
break;
if (entry->out == 0)
return -EINVAL;
return max9485_update_bits(clk_hw->drvdata,
MAX9485_FREQ_MASK,
entry->reg_value);
}
static unsigned long max9485_clkout_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct max9485_clk_hw *clk_hw = to_max9485_clk(hw);
struct max9485_driver_data *drvdata = clk_hw->drvdata;
u8 val = drvdata->reg_value & MAX9485_FREQ_MASK;
const struct max9485_rate *entry;
for (entry = max9485_rates; entry->out != 0; entry++)
if (val == entry->reg_value)
return entry->out;
return 0;
}
static long max9485_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
const struct max9485_rate *curr, *prev = NULL;
for (curr = max9485_rates; curr->out != 0; curr++) {
/* Exact matches */
if (curr->out == rate)
return rate;
/*
* Find the first entry that has a frequency higher than the
* requested one.
*/
if (curr->out > rate) {
unsigned int mid;
/*
* If this is the first entry, clamp the value to the
* lowest possible frequency.
*/
if (!prev)
return curr->out;
/*
* Otherwise, determine whether the previous entry or
* current one is closer.
*/
mid = prev->out + ((curr->out - prev->out) / 2);
return (mid > rate) ? prev->out : curr->out;
}
prev = curr;
}
/* If the last entry was still too high, clamp the value */
return prev->out;
}
struct max9485_clk {
const char *name;
int parent_index;
const struct clk_ops ops;
u8 enable_bit;
};
static const struct max9485_clk max9485_clks[MAX9485_NUM_CLKS] = {
[MAX9485_MCLKOUT] = {
.name = "mclkout",
.parent_index = -1,
.enable_bit = MAX9485_MCLK_ENABLE,
.ops = {
.prepare = max9485_clk_prepare,
.unprepare = max9485_clk_unprepare,
},
},
[MAX9485_CLKOUT] = {
.name = "clkout",
.parent_index = -1,
.ops = {
.set_rate = max9485_clkout_set_rate,
.round_rate = max9485_clkout_round_rate,
.recalc_rate = max9485_clkout_recalc_rate,
},
},
[MAX9485_CLKOUT1] = {
.name = "clkout1",
.parent_index = MAX9485_CLKOUT,
.enable_bit = MAX9485_CLKOUT1_ENABLE,
.ops = {
.prepare = max9485_clk_prepare,
.unprepare = max9485_clk_unprepare,
},
},
[MAX9485_CLKOUT2] = {
.name = "clkout2",
.parent_index = MAX9485_CLKOUT,
.enable_bit = MAX9485_CLKOUT2_ENABLE,
.ops = {
.prepare = max9485_clk_prepare,
.unprepare = max9485_clk_unprepare,
},
},
};
static struct clk_hw *
max9485_of_clk_get(struct of_phandle_args *clkspec, void *data)
{
struct max9485_driver_data *drvdata = data;
unsigned int idx = clkspec->args[0];
return &drvdata->hw[idx].hw;
}
static int max9485_i2c_probe(struct i2c_client *client)
{
struct max9485_driver_data *drvdata;
struct device *dev = &client->dev;
const char *xclk_name;
int i, ret;
drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
if (!drvdata)
return -ENOMEM;
drvdata->xclk = devm_clk_get(dev, "xclk");
if (IS_ERR(drvdata->xclk))
return PTR_ERR(drvdata->xclk);
xclk_name = __clk_get_name(drvdata->xclk);
drvdata->supply = devm_regulator_get(dev, "vdd");
if (IS_ERR(drvdata->supply))
return PTR_ERR(drvdata->supply);
ret = regulator_enable(drvdata->supply);
if (ret < 0)
return ret;
drvdata->reset_gpio =
devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
if (IS_ERR(drvdata->reset_gpio))
return PTR_ERR(drvdata->reset_gpio);
i2c_set_clientdata(client, drvdata);
drvdata->client = client;
ret = i2c_master_recv(drvdata->client, &drvdata->reg_value,
sizeof(drvdata->reg_value));
if (ret < 0) {
dev_warn(dev, "Unable to read device register: %d\n", ret);
return ret;
}
for (i = 0; i < MAX9485_NUM_CLKS; i++) {
int parent_index = max9485_clks[i].parent_index;
const char *name;
if (of_property_read_string_index(dev->of_node,
"clock-output-names",
i, &name) == 0) {
drvdata->hw[i].init.name = name;
} else {
drvdata->hw[i].init.name = max9485_clks[i].name;
}
drvdata->hw[i].init.ops = &max9485_clks[i].ops;
drvdata->hw[i].init.num_parents = 1;
drvdata->hw[i].init.flags = 0;
if (parent_index > 0) {
drvdata->hw[i].init.parent_names =
&drvdata->hw[parent_index].init.name;
drvdata->hw[i].init.flags |= CLK_SET_RATE_PARENT;
} else {
drvdata->hw[i].init.parent_names = &xclk_name;
}
drvdata->hw[i].enable_bit = max9485_clks[i].enable_bit;
drvdata->hw[i].hw.init = &drvdata->hw[i].init;
drvdata->hw[i].drvdata = drvdata;
ret = devm_clk_hw_register(dev, &drvdata->hw[i].hw);
if (ret < 0)
return ret;
}
return devm_of_clk_add_hw_provider(dev, max9485_of_clk_get, drvdata);
}
static int __maybe_unused max9485_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct max9485_driver_data *drvdata = i2c_get_clientdata(client);
gpiod_set_value_cansleep(drvdata->reset_gpio, 0);
return 0;
}
static int __maybe_unused max9485_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct max9485_driver_data *drvdata = i2c_get_clientdata(client);
int ret;
gpiod_set_value_cansleep(drvdata->reset_gpio, 1);
ret = i2c_master_send(client, &drvdata->reg_value,
sizeof(drvdata->reg_value));
return ret < 0 ? ret : 0;
}
static const struct dev_pm_ops max9485_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(max9485_suspend, max9485_resume)
};
static const struct of_device_id max9485_dt_ids[] = {
{ .compatible = "maxim,max9485", },
{ }
};
MODULE_DEVICE_TABLE(of, max9485_dt_ids);
static const struct i2c_device_id max9485_i2c_ids[] = {
{ .name = "max9485", },
{ }
};
MODULE_DEVICE_TABLE(i2c, max9485_i2c_ids);
static struct i2c_driver max9485_driver = {
.driver = {
.name = "max9485",
.pm = &max9485_pm_ops,
.of_match_table = max9485_dt_ids,
},
.probe_new = max9485_i2c_probe,
.id_table = max9485_i2c_ids,
};
module_i2c_driver(max9485_driver);
MODULE_AUTHOR("Daniel Mack <daniel@zonque.org>");
MODULE_DESCRIPTION("MAX9485 Programmable Audio Clock Generator");
MODULE_LICENSE("GPL v2");
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