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clk: keystone: syscon-clk: Add support for audio refclk

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TI's AM62 SoC can optionally provide two audio reference clocks
(AUDIO_REFCLKx) to external peripherals.

By default this reference clock is looped-back inside the SoC to a mux
that goes to McASP AHCLK, but can optionally be enabled as an output to
peripherals outside the SoC by setting a bit through CTRL_MMR registers.

This bit only controls the direction of the clock, while the parent
is a muxed input from sci-clk [1] which may be a configurable PLL or a
master clock from one of the McASP instances.

Link: http://downloads.ti.com/tisci/esd/latest/5_soc_doc/am62x/clocks.html#clocks-for-board0-device [1]
Signed-off-by: Jai Luthra <j-luthra@ti.com>
Link: https://lore.kernel.org/r/20230515-refclk-v3-2-37c0b550f406@ti.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
This commit is contained in:
Jai Luthra 2023-06-15 17:25:36 +05:30 committed by Stephen Boyd
parent daecb57cc4
commit 6acab96ee3
1 changed files with 40 additions and 5 deletions
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45
drivers/clk/keystone/syscon-clk.c
View file

@ -4,10 +4,12 @@
*/
#include <linux/clk-provider.h>
#include <linux/kernel.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
struct ti_syscon_gate_clk_priv {
struct clk_hw hw;
@ -61,21 +63,31 @@ static const struct clk_ops ti_syscon_gate_clk_ops = {
static struct clk_hw
*ti_syscon_gate_clk_register(struct device *dev, struct regmap *regmap,
const char *parent_name,
const struct ti_syscon_gate_clk_data *data)
{
struct ti_syscon_gate_clk_priv *priv;
struct clk_init_data init;
char *name = NULL;
int ret;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return ERR_PTR(-ENOMEM);
init.name = data->name;
init.ops = &ti_syscon_gate_clk_ops;
init.parent_names = NULL;
init.num_parents = 0;
init.flags = 0;
if (parent_name) {
name = kasprintf(GFP_KERNEL, "%s:%s", data->name, parent_name);
init.name = name;
init.parent_names = &parent_name;
init.num_parents = 1;
init.flags = CLK_SET_RATE_PARENT;
} else {
init.name = data->name;
init.parent_names = NULL;
init.num_parents = 0;
init.flags = 0;
}
priv->regmap = regmap;
priv->reg = data->offset;
@ -83,6 +95,10 @@ static struct clk_hw
priv->hw.init = &init;
ret = devm_clk_hw_register(dev, &priv->hw);
if (name)
kfree(init.name);
if (ret)
return ERR_PTR(ret);
@ -94,8 +110,9 @@ static int ti_syscon_gate_clk_probe(struct platform_device *pdev)
const struct ti_syscon_gate_clk_data *data, *p;
struct clk_hw_onecell_data *hw_data;
struct device *dev = &pdev->dev;
int num_clks, num_parents, i;
const char *parent_name;
struct regmap *regmap;
int num_clks, i;
data = device_get_match_data(dev);
if (!data)
@ -110,6 +127,13 @@ static int ti_syscon_gate_clk_probe(struct platform_device *pdev)
for (p = data; p->name; p++)
num_clks++;
num_parents = of_clk_get_parent_count(dev->of_node);
if (of_device_is_compatible(dev->of_node, "ti,am62-audio-refclk") &&
num_parents == 0) {
return dev_err_probe(dev, -EINVAL,
"must specify a parent clock\n");
}
hw_data = devm_kzalloc(dev, struct_size(hw_data, hws, num_clks),
GFP_KERNEL);
if (!hw_data)
@ -117,8 +141,10 @@ static int ti_syscon_gate_clk_probe(struct platform_device *pdev)
hw_data->num = num_clks;
parent_name = of_clk_get_parent_name(dev->of_node, 0);
for (i = 0; i < num_clks; i++) {
hw_data->hws[i] = ti_syscon_gate_clk_register(dev, regmap,
parent_name,
&data[i]);
if (IS_ERR(hw_data->hws[i]))
dev_warn(dev, "failed to register %s\n",
@ -166,6 +192,11 @@ static const struct ti_syscon_gate_clk_data am62_clk_data[] = {
{ /* Sentinel */ },
};
static const struct ti_syscon_gate_clk_data am62_audio_clk_data[] = {
TI_SYSCON_CLK_GATE("audio_refclk", 0x0, 15),
{ /* Sentinel */ },
};
static const struct of_device_id ti_syscon_gate_clk_ids[] = {
{
.compatible = "ti,am654-ehrpwm-tbclk",
@ -179,6 +210,10 @@ static const struct of_device_id ti_syscon_gate_clk_ids[] = {
.compatible = "ti,am62-epwm-tbclk",
.data = &am62_clk_data,
},
{
.compatible = "ti,am62-audio-refclk",
.data = &am62_audio_clk_data,
},
{ }
};
MODULE_DEVICE_TABLE(of, ti_syscon_gate_clk_ids);