Staging: poch: Add sample Rx code

Add sample code Rx to README.
Signed-off-by: Vijay Kumar B <vijaykumar@bravegnu.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/poch/README

@@ -9,5 +9,128 @@ TODO:
 	- audit userspace interfaces
 	- get reserved major/minor if needed
 
+Sample Code:
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <sys/ioctl.h>
+#include <poll.h>
+#include <stdio.h>
+#include <error.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdint.h>
+
+#include <sysfs/libsysfs.h>
+
+#include <poch.h>
+
+struct pconsume {
+	uint32_t * offsets;
+	uint32_t nfetch;
+	uint32_t nflush;
+};
+
+uint32_t offsets[10];
+
+void process_group(unsigned char *buf, uint32_t size)
+{
+	uint16_t *buf16 = (uint16_t *)buf;
+
+	printf("RX: %p %u %04x %04x %04x %04x %04x %04x\n", buf, size,
+	       buf16[0], buf16[1], buf16[2], buf16[3], buf16[4], buf16[5]);
+}
+
+int main()
+{
+	struct sysfs_attribute *attr;
+	char *path;
+	int ret;
+	unsigned long mmap_size;
+	int fd;
+	unsigned char *cbuf;
+
+	uint32_t nflush;
+	struct pollfd poll_fds;
+	int count = 0;
+	int i;
+
+	path = "/sys/class/pocketchange/poch0/ch0/block_size";
+	attr = sysfs_open_attribute(path);
+	ret = sysfs_write_attribute(attr, "256", strlen("256"));
+	if (ret == -1)
+		error(1, errno, "error writing attribute %s", path);
+	sysfs_close_attribute(attr);
+
+	path = "/sys/class/pocketchange/poch0/ch0/group_size";
+	attr = sysfs_open_attribute(path);
+	ret = sysfs_write_attribute(attr, "4096", strlen("4096"));
+	if (ret == -1)
+		error(1, errno, "error writing attribute %s", path);
+	sysfs_close_attribute(attr);
+
+	path = "/sys/class/pocketchange/poch0/ch0/group_count";
+	attr = sysfs_open_attribute(path);
+	ret = sysfs_write_attribute(attr, "64", strlen("64"));
+	if (ret == -1)
+		error(1, errno, "error writing attribute %s", path);
+	sysfs_close_attribute(attr);
+
+	fd = open("/dev/ch0", O_RDWR);
+	if (fd == -1)
+		error(1, errno, "error opening device node");
+
+	path = "/sys/class/pocketchange/poch0/ch0/mmap_size";
+	attr = sysfs_open_attribute(path);
+	ret = sysfs_read_attribute(attr);
+	if (ret == -1)
+		error(1, errno, "error reading attribute %s", path);
+	printf("%s", attr->value);
+	sscanf(attr->value, "%lu", &mmap_size);
+	sysfs_close_attribute(attr);
+
+	cbuf = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
+		    MAP_PRIVATE, fd, 0);
+	if (cbuf == MAP_FAILED)
+		error(1, errno, "error mapping DMA buffers");
+
+	ret = ioctl(fd, POCH_IOC_TRANSFER_START, 0);
+	if (ret == -1)
+		error(1, errno, "error starting transfer");
+
+	nflush = 0;
+	while (1) {
+		struct pconsume consume;
+
+		consume.offsets = offsets;
+		consume.nfetch = 10;
+		consume.nflush = nflush;
+
+		ret = ioctl(fd, POCH_IOC_CONSUME, &consume);
+		if (ret == -1)
+			error(1, errno, "error consuming groups");
+
+		nflush = consume.nfetch;
+
+		for (i = 0; i < nflush; i++) {
+			process_group(cbuf + consume.offsets[i], 4096);
+
+			count++;
+			if (count == 1000)
+				break;
+		}
+
+		if (count == 1000)
+			break;
+	}
+
+	ret = ioctl(fd, POCH_IOC_TRANSFER_STOP, 0);
+	if (ret == -1)
+		error(1, errno, "error starting transfer");
+
+	return 0;
+}
+
 Please send patches to Greg Kroah-Hartman <greg@kroah.com> and
 Vijay Kumar <vijaykumar@bravegnu.org> and Jaya Kumar <jayakumar.lkml@gmail.com>