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#include <linux/clk-provider.h>
#include <linux/clkdev.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
struct ipaq_audio_clk {
struct clk_hw clk;
struct clk_lookup *cl;
struct gpio_desc *gpios[2];
};
#define to_ipaq_audio_clk(x) container_of(x, struct ipaq_audio_clk, clk)
static const char *clk_names[2] = { "clk0", "clk1" };
static unsigned long ipaq_audio_clk_rates[] = {
12288000,
11289600,
4096000,
5624500,
};
static unsigned long ipaq_audio_clk_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct ipaq_audio_clk *ia = to_ipaq_audio_clk(hw);
unsigned int clk0 = !!gpiod_get_value(ia->gpios[0]);
unsigned int clk1 = !!gpiod_get_value(ia->gpios[1]);
unsigned int idx = clk1 * 2 + clk0;
return ipaq_audio_clk_rates[idx];
}
static long ipaq_audio_clk_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
int i, best = -1;
long diff, best_diff = LONG_MAX;
for (i = 0; i < ARRAY_SIZE(ipaq_audio_clk_rates); i++) {
diff = ipaq_audio_clk_rates[i] - rate;
if (diff < 0)
diff = -diff;
if (diff < best_diff) {
best_diff = diff;
best = i;
}
}
return best == -1 ? -EINVAL : ipaq_audio_clk_rates[best];
}
static int ipaq_audio_clk_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct ipaq_audio_clk *ia = to_ipaq_audio_clk(hw);
DECLARE_BITMAP(values, 2) = { 0, };
int i;
for (i = 0; i < ARRAY_SIZE(ipaq_audio_clk_rates); i++) {
if (ipaq_audio_clk_rates[i] == rate) {
__assign_bit(0, values, !!(i & 1));
__assign_bit(1, values, !!(i & 2));
gpiod_set_array_value(2, ia->gpios, NULL, values);
return 0;
}
}
return -EINVAL;
}
static const struct clk_ops ipaq_audio_clk_ops = {
.recalc_rate = ipaq_audio_clk_recalc_rate,
.round_rate = ipaq_audio_clk_round_rate,
.set_rate = ipaq_audio_clk_set_rate,
};
static struct clk_init_data ipaq_audio_clk_init = {
.name = "ipaq-audio",
.ops = &ipaq_audio_clk_ops,
};
static int ipaq_audio_clk_probe(struct platform_device *pdev)
{
struct ipaq_audio_clk *ia;
int i, ret;
ia = devm_kzalloc(&pdev->dev, sizeof(*ia), GFP_KERNEL);
if (!ia)
return -ENOMEM;
for (i = 0; i < ARRAY_SIZE(clk_names); i++) {
ia->gpios[i] = devm_gpiod_get(&pdev->dev, clk_names[i],
GPIOD_OUT_LOW);
if (IS_ERR(ia->gpios[i]))
return PTR_ERR(ia->gpios[i]);
}
platform_set_drvdata(pdev, ia);
ia->clk.init = &ipaq_audio_clk_init;
ret = devm_clk_hw_register(&pdev->dev, &ia->clk);
if (ret)
return ret;
ia->cl = clkdev_hw_create(&ia->clk, "ext", "h3xxx-asoc");
return ia->cl ? 0 : -ENOMEM;
}
static int ipaq_audio_clk_remove(struct platform_device *pdev)
{
struct ipaq_audio_clk *ia = platform_get_drvdata(pdev);
clkdev_drop(ia->cl);
return 0;
}
static struct platform_driver ipaq_audio_clk_driver = {
.probe = ipaq_audio_clk_probe,
.remove = ipaq_audio_clk_remove,
.driver = {
.name = "ipaq-audio-clk",
},
};
module_platform_driver(ipaq_audio_clk_driver);
MODULE_AUTHOR("Russell King <rmk+kernel@armlinux.org.uk>");
MODULE_DESCRIPTION("iPAQ Audio clock driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:ipaq-audio-clock");
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