[PATCH 11/12] misc: flexcard: Support timestamp trigger selection

[Holger Dengler]

The Flexcard timestamp counter can be triggered from two external
trigger inputs or an internal clock at 1 MHz, 10 Mhz or 100 MHz.
Add support for timestamp trigger selection.

Signed-off-by: Holger Dengler <dengler@xxxxxxxxxxxxx>
Signed-off-by: Benedikt Spranger <b.spranger@xxxxxxxxxxxxx>
cc: Arnd Bergmann <arnd@xxxxxxxx>
cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/misc/flexcard_posixclock.c | 63 +++++++++++++++++++++++++++++++++++---
 include/uapi/linux/flexcard.h      | 16 ++++++++++
 2 files changed, 75 insertions(+), 4 deletions(-)

diff --git a/drivers/misc/flexcard_posixclock.c b/drivers/misc/flexcard_posixclock.c
index 146f0f3..b4cb38e 100644
--- a/drivers/misc/flexcard_posixclock.c
+++ b/drivers/misc/flexcard_posixclock.c
@@ -12,6 +12,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
+#include <linux/flexcard.h>
 #include <linux/fs.h>
 #include <linux/miscdevice.h>
 #include <linux/platform_device.h>
@@ -35,12 +36,15 @@ struct flexcard_clk {
 	struct device		*dev;
 	void __iomem		*ts64;
 	void __iomem		*reset;
+	u32			mul;
+	struct flexcard_clk_desc desc;
 };
 
 static int flexcard_clk_getres(struct posix_clock *pc, struct timespec *tp)
 {
+	struct flexcard_clk *clk = container_of(pc, struct flexcard_clk, clock);
 	tp->tv_sec = 0;
-	tp->tv_nsec = 1000;
+	tp->tv_nsec = clk->mul;
 
 	return 0;
 }
@@ -57,8 +61,8 @@ static int flexcard_clk_gettime(struct posix_clock *pc, struct timespec *tp)
 	if (upper != readl(clk->ts64))
 		goto retry;
 
-	tp->tv_sec = div_u64_rem(now, 1000000, &rem);
-	tp->tv_nsec = rem * 1000;
+	tp->tv_sec = div_u64_rem(now, clk->desc.freq, &rem);
+	tp->tv_nsec = rem * clk->mul;
 
 	return 0;
 }
@@ -77,11 +81,59 @@ static int flexcard_clk_settime(struct posix_clock *pc,
 	return 0;
 }
 
+static long flexcard_clk_ioctl(struct posix_clock *pc, unsigned int cmd,
+			       unsigned long arg)
+{
+	struct flexcard_clk *clk = container_of(pc, struct flexcard_clk, clock);
+	struct flexcard_clk_desc desc;
+
+	switch (cmd) {
+	case FCSCLKSRC:
+		if (copy_from_user(&desc, (void __user *)arg, sizeof(desc)))
+			return -EFAULT;
+
+		switch (desc.type) {
+		case FLEXCARD_CLK_1MHZ:
+			desc.freq = 1000000;
+			break;
+		case FLEXCARD_CLK_10MHZ:
+			desc.freq = 10000000;
+			break;
+		case FLEXCARD_CLK_100MHZ:
+			desc.freq = 100000000;
+			break;
+		case FLEXCARD_CLK_EXT1:
+		case FLEXCARD_CLK_EXT2:
+			if (desc.freq < 1 || desc.freq > NSEC_PER_SEC)
+				return -EINVAL;
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		clk->desc = desc;
+		clk->mul = NSEC_PER_SEC/desc.freq;
+		writel(clk->desc.type, clk->ts64 + CLKSEL_OFF);
+		writel(FLEXCARD_RST_TS, clk->reset);
+
+		break;
+	case FCGCLKSRC:
+		if (copy_to_user((void __user *)arg, &clk->desc, sizeof(desc)))
+			return -EFAULT;
+		break;
+	default:
+		return -ENOTTY;
+	}
+
+	return 0;
+}
+
 static struct posix_clock_operations flexcard_clk_ops = {
 	.owner		= THIS_MODULE,
 	.clock_getres	= flexcard_clk_getres,
 	.clock_gettime	= flexcard_clk_gettime,
 	.clock_settime	= flexcard_clk_settime,
+	.ioctl		= flexcard_clk_ioctl,
 };
 
 static int flexcard_clk_iomap(struct platform_device *pdev)
@@ -139,8 +191,11 @@ static int flexcard_clk_probe(struct platform_device *pdev)
 
 	clk->devid = MKDEV(major, cell->id);
 	clk->clock.ops = flexcard_clk_ops;
+	clk->desc.type = FLEXCARD_CLK_1MHZ;
+	clk->desc.freq = 1000000;
+	clk->mul = 1000;
 
-	writel(FLEXCARD_CLK_1MHZ, clk->ts64 + CLKSEL_OFF);
+	writel(clk->desc.type, clk->ts64 + CLKSEL_OFF);
 	writel(FLEXCARD_RST_TS, clk->reset);
 
 	clk->dev = device_create(flexcard_clk_class, &pdev->dev, clk->devid,
diff --git a/include/uapi/linux/flexcard.h b/include/uapi/linux/flexcard.h
index 4e9f07b4..3ad0bf4 100644
--- a/include/uapi/linux/flexcard.h
+++ b/include/uapi/linux/flexcard.h
@@ -15,6 +15,22 @@
 
 #include <linux/types.h>
 
+enum flexcard_clk_type {
+	FLEXCARD_CLK_1MHZ = 0x0,
+	FLEXCARD_CLK_10MHZ = 0x1,
+	FLEXCARD_CLK_100MHZ = 0x2,
+	FLEXCARD_CLK_EXT1 = 0x11,
+	FLEXCARD_CLK_EXT2 = 0x12,
+};
+
+struct flexcard_clk_desc {
+	enum flexcard_clk_type type;
+	__u32 freq;
+};
+
+#define FCGCLKSRC       _IOR(0xeb, 0, struct flexcard_clk_desc)
+#define FCSCLKSRC       _IOW(0xeb, 1, struct flexcard_clk_desc)
+
 struct fc_version {
 	__u8	dev;
 	__u8	min;
-- 
2.1.4