clk: add iPAQ audio sysclock driver

Add clock driver for iPAQ audio sysclock.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

3 files changed, 154 insertions, 0 deletions

diff --git a/arch/arm/mach-sa1100/h3600.c b/arch/arm/mach-sa1100/h3600.c
index 28ce2d1353c7..029f949cbc56 100644
--- a/arch/arm/mach-sa1100/h3600.c
+++ b/arch/arm/mach-sa1100/h3600.c
@@ -10,6 +10,7 @@
 #include <linux/kernel.h>
 #include <linux/gpio.h>
 #include <linux/gpio/machine.h>
+#include <linux/platform_device.h>
 
 #include <video/sa1100fb.h>
 
@@ -116,10 +117,27 @@ static struct gpiod_lookup_table h3600_sleeve_gpio_table = {
 	},
 };
 
+static struct gpiod_lookup_table h3600_audio_clk_gpio_table = {
+	.dev_id = "ipaq-audio-clk",
+	.table = {
+		GPIO_LOOKUP("gpio", 12, "clk0", GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP("gpio", 13, "clk1", GPIO_ACTIVE_HIGH),
+		{ },
+	},
+};
+
+static struct platform_device_info h3600_audio_clk_device = {
+	.name = "ipaq-audio-clk",
+	.id = -1,
+};
+
 static void __init h3600_mach_init(void)
 {
 	gpiod_add_lookup_table(&h3600_irda_gpio_table);
 	gpiod_add_lookup_table(&h3600_sleeve_gpio_table);
+	gpiod_add_lookup_table(&h3600_audio_clk_gpio_table);
+
+	platform_device_register_full(&h3600_audio_clk_device);
 
 	h3xxx_mach_init();
 
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index da8fcf147eb1..d80fa7dbc3ad 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_COMMON_CLK_ASPEED)		+= clk-aspeed.o
 obj-$(CONFIG_MACH_ASPEED_G6)		+= clk-ast2600.o
 obj-$(CONFIG_ARCH_HIGHBANK)		+= clk-highbank.o
 obj-$(CONFIG_CLK_HSDK)			+= clk-hsdk-pll.o
+obj-$(CONFIG_SA1100_H3600)		+= clk-ipaq.o
 obj-$(CONFIG_COMMON_CLK_LOCHNAGAR)	+= clk-lochnagar.o
 obj-$(CONFIG_COMMON_CLK_MAX77686)	+= clk-max77686.o
 obj-$(CONFIG_COMMON_CLK_MAX9485)	+= clk-max9485.o
diff --git a/drivers/clk/clk-ipaq.c b/drivers/clk/clk-ipaq.c
new file mode 100644
index 000000000000..af48cdb7da53
--- /dev/null
+++ b/drivers/clk/clk-ipaq.c
@@ -0,0 +1,135 @@
+#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");