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clk: gpio: Make into a platform driver
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clk_get() for DT based clks already returns EPROBE_DEFER when the
OF clk provider is not present. So having all this code in the
clk provider to return EPROBE_DEFER when the gpio isn't ready yet
can be replaced with a platform driver that doesn't add the clk
provider until the gpio can be requested. Get rid of the
OF_CLK_DECLARE and convert this to a platform driver instead.

Tested-by: Jyri Sarha <jsarha@ti.com>
Cc: Sergej Sawazki <ce3a@gmx.de>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Jon Nettleton <jon@solid-run.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
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Stephen Boyd committed Feb 7, 2016
1 parent 4106a3d commit 14b04f2
Showing 1 changed file with 52 additions and 113 deletions.
165 changes: 52 additions & 113 deletions drivers/clk/clk-gpio.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,8 @@
#include <linux/of_gpio.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/of_device.h>

/**
* DOC: basic gpio gated clock which can be enabled and disabled
Expand Down Expand Up @@ -199,134 +201,71 @@ struct clk *clk_register_gpio_mux(struct device *dev, const char *name,
}
EXPORT_SYMBOL_GPL(clk_register_gpio_mux);

#ifdef CONFIG_OF
/**
* clk_register_get() has to be delayed, because -EPROBE_DEFER
* can not be handled properly at of_clk_init() call time.
*/

struct clk_gpio_delayed_register_data {
const char *gpio_name;
int num_parents;
const char **parent_names;
struct device_node *node;
struct mutex lock;
struct clk *clk;
struct clk *(*clk_register_get)(const char *name,
const char * const *parent_names, u8 num_parents,
unsigned gpio, bool active_low);
};

static struct clk *of_clk_gpio_delayed_register_get(
struct of_phandle_args *clkspec, void *_data)
static int gpio_clk_driver_probe(struct platform_device *pdev)
{
struct clk_gpio_delayed_register_data *data = _data;
struct clk *clk;
int gpio;
struct device_node *node = pdev->dev.of_node;
const char **parent_names, *gpio_name;
int num_parents, gpio;
enum of_gpio_flags of_flags;
struct clk *clk;
bool active_low, is_mux;

num_parents = of_clk_get_parent_count(node);
if (num_parents < 0)
return -EINVAL;

mutex_lock(&data->lock);
if (num_parents) {
parent_names = devm_kcalloc(&pdev->dev, num_parents,
sizeof(char *), GFP_KERNEL);
if (!parent_names)
return -ENOMEM;

if (data->clk) {
mutex_unlock(&data->lock);
return data->clk;
of_clk_parent_fill(node, parent_names, num_parents);
} else {
parent_names = NULL;
}

gpio = of_get_named_gpio_flags(data->node, data->gpio_name, 0,
&of_flags);
is_mux = of_device_is_compatible(node, "gpio-mux-clock");

gpio_name = is_mux ? "select-gpios" : "enable-gpios";
gpio = of_get_named_gpio_flags(node, gpio_name, 0, &of_flags);
if (gpio < 0) {
mutex_unlock(&data->lock);
if (gpio == -EPROBE_DEFER)
pr_debug("%s: %s: GPIOs not yet available, retry later\n",
data->node->name, __func__);
node->name, __func__);
else
pr_err("%s: %s: Can't get '%s' DT property\n",
data->node->name, __func__,
data->gpio_name);
return ERR_PTR(gpio);
node->name, __func__,
gpio_name);
return gpio;
}

clk = data->clk_register_get(data->node->name, data->parent_names,
data->num_parents, gpio, of_flags & OF_GPIO_ACTIVE_LOW);
if (IS_ERR(clk))
goto out;

data->clk = clk;
out:
mutex_unlock(&data->lock);

return clk;
}

static struct clk *of_clk_gpio_gate_delayed_register_get(const char *name,
const char * const *parent_names, u8 num_parents,
unsigned gpio, bool active_low)
{
return clk_register_gpio_gate(NULL, name, parent_names ?
parent_names[0] : NULL, gpio, active_low, 0);
}

static struct clk *of_clk_gpio_mux_delayed_register_get(const char *name,
const char * const *parent_names, u8 num_parents, unsigned gpio,
bool active_low)
{
return clk_register_gpio_mux(NULL, name, parent_names, num_parents,
gpio, active_low, 0);
}

static void __init of_gpio_clk_setup(struct device_node *node,
const char *gpio_name,
struct clk *(*clk_register_get)(const char *name,
const char * const *parent_names,
u8 num_parents,
unsigned gpio, bool active_low))
{
struct clk_gpio_delayed_register_data *data;
const char **parent_names;
int i, num_parents;

num_parents = of_clk_get_parent_count(node);
if (num_parents < 0)
return;

data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return;
active_low = of_flags & OF_GPIO_ACTIVE_LOW;

if (num_parents) {
parent_names = kcalloc(num_parents, sizeof(char *), GFP_KERNEL);
if (!parent_names) {
kfree(data);
return;
}

for (i = 0; i < num_parents; i++)
parent_names[i] = of_clk_get_parent_name(node, i);
} else {
parent_names = NULL;
}

data->num_parents = num_parents;
data->parent_names = parent_names;
data->node = node;
data->gpio_name = gpio_name;
data->clk_register_get = clk_register_get;
mutex_init(&data->lock);
if (is_mux)
clk = clk_register_gpio_mux(&pdev->dev, node->name,
parent_names, num_parents, gpio, active_low, 0);
else
clk = clk_register_gpio_gate(&pdev->dev, node->name,
parent_names ? parent_names[0] : NULL, gpio,
active_low, 0);
if (IS_ERR(clk))
return PTR_ERR(clk);

of_clk_add_provider(node, of_clk_gpio_delayed_register_get, data);
return of_clk_add_provider(node, of_clk_src_simple_get, clk);
}

static void __init of_gpio_gate_clk_setup(struct device_node *node)
{
of_gpio_clk_setup(node, "enable-gpios",
of_clk_gpio_gate_delayed_register_get);
}
CLK_OF_DECLARE(gpio_gate_clk, "gpio-gate-clock", of_gpio_gate_clk_setup);
static const struct of_device_id gpio_clk_match_table[] = {
{ .compatible = "gpio-mux-clock" },
{ .compatible = "gpio-gate-clock" },
{ }
};

void __init of_gpio_mux_clk_setup(struct device_node *node)
{
of_gpio_clk_setup(node, "select-gpios",
of_clk_gpio_mux_delayed_register_get);
}
CLK_OF_DECLARE(gpio_mux_clk, "gpio-mux-clock", of_gpio_mux_clk_setup);
#endif
static struct platform_driver gpio_clk_driver = {
.probe = gpio_clk_driver_probe,
.driver = {
.name = "gpio-clk",
.of_match_table = gpio_clk_match_table,
},
};
builtin_platform_driver(gpio_clk_driver);

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