DMA support initial

src/drivers/elphel/Kconfig

@@ -4,9 +4,15 @@
                                                                                                                                      
 menu "Elphel devices"
 config ELPHEL393
-	tristate "Support Elphel 10393 board voltage regulator"
+        tristate "Support Elphel 10393 board voltage regulator, DMA memory allocator"
 # add more
 #       depends on I2C && SYSFS
         help
           Say Y here if you have a Elphel board 10393.
+
+config ELPHELDRVONMICROZED
+        tristate "Provide only Elphel features which are compatible with Microzed"
+        help
+          Say Y here if you debug Elpel camera code on Microzed board.
+
 endmenu  

src/drivers/elphel/Makefile

@@ -3,3 +3,5 @@
 #                                                                                                                                    
                                                                                                                                      
 obj-$(CONFIG_ELPHEL393)         += elphel393-pwr.o  
+obj-$(CONFIG_ELPHEL393)         += elphel393-mem.o  
+obj-$(CONFIG_ELPHELDRVONMICROZED)          += elphel393-mem.o  

src/drivers/elphel/elphel393-mem.c

+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/kernel.h>
+#include <linux/bootmem.h>
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/dma-direction.h>
+#include <asm/dma-mapping.h>
+
+#define SYSFS_PERMISSIONS         0644 /* default permissions for sysfs files */
+#define SYSFS_READONLY            0444
+
+
+static ssize_t get_paddr(struct device *dev, struct device_attribute *attr, char *buf);
+
+struct elphel_buf_t
+{
+	void *vaddr;
+	dma_addr_t paddr;
+	ssize_t size;
+};
+
+static struct elphel_buf_t elphel_buf = {
+	.vaddr = NULL,
+	.paddr = 0,
+	.size = 0
+};
+
+static int __init elphelmem_init(void)
+{
+    struct device_node *node;
+	const __be32 *bufsize_be;
+
+	printk("======== Allocating memory buffer ========\n");
+
+	node = of_find_node_by_name(NULL, "elphel393-mem");
+	if (!node)
+	{
+		printk("ERROR: No node found\n");
+		return -ENODEV;
+	}
+
+	bufsize_be = (__be32 *)of_get_property(node, "memsize", NULL);
+	elphel_buf.size = be32_to_cpup(bufsize_be);
+
+	elphel_buf.vaddr = dma_alloc_coherent(NULL,(elphel_buf.size*PAGE_SIZE),&(elphel_buf.paddr),GFP_KERNEL);
+
+    if(elphel_buf.paddr)
+    {
+    	printk("Allocated %u pages at address %x\n", (u32)elphel_buf.size, (u32)elphel_buf.paddr);
+    }
+    else printk("ERROR allocating memory buffer");
+
+    return 0;
+}
+
+static void __exit elphelmem_exit(void)
+{
+    printk("Goodbye Cruel World!\n");
+}
+
+
+
+// SYSFS
+
+static ssize_t get_paddr(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf,"%x\n", (u32)elphel_buf.paddr);
+}
+
+static ssize_t get_size(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf,"%u\n", elphel_buf.size);
+}
+static DEVICE_ATTR(buffer_address,  SYSFS_PERMISSIONS & SYSFS_READONLY,    get_paddr,          NULL);
+static DEVICE_ATTR(buffer_pages,  SYSFS_PERMISSIONS & SYSFS_READONLY,    get_size,          NULL);
+
+static struct attribute *root_dev_attrs[] = {
+		&dev_attr_buffer_address.attr,
+		&dev_attr_buffer_pages.attr,
+	    NULL
+};
+
+static const struct attribute_group dev_attr_root_group = {
+	.attrs = root_dev_attrs,
+	.name  = NULL,
+};
+
+static int elphel393_mem_sysfs_register(struct platform_device *pdev)
+{
+	int retval=0;
+	struct device *dev = &pdev->dev;
+	if (&dev->kobj) {
+		if (((retval = sysfs_create_group(&dev->kobj, &dev_attr_root_group)))<0) return retval;
+	}
+	return retval;
+}
+
+static int elphel393_mem_probe(struct platform_device *pdev)
+{
+	elphel393_mem_sysfs_register(pdev);
+	dev_info(&pdev->dev,"Probing elphel393-mem\n");
+	return 0;
+}
+
+static int elphel393_mem_remove(struct platform_device *pdev)
+{
+	dev_info(&pdev->dev,"Removing elphel393-mem");
+	return 0;
+}
+
+static struct of_device_id elphel393_mem_of_match[] = {
+	{ .compatible = "elphel,elphel393-mem-1.00", },
+	{ /* end of table */}
+};
+MODULE_DEVICE_TABLE(of, elphel393_pwr_of_match);
+
+static struct platform_driver elphel393_mem = {
+	.probe   = elphel393_mem_probe,
+	.remove  = elphel393_mem_remove,
+	.driver  = {
+		.name  = "elphel393-mem",
+		.owner = THIS_MODULE,
+		.of_match_table = elphel393_mem_of_match,
+		.pm = NULL, /* power management */
+	},
+};
+
+module_platform_driver(elphel393_mem);
+module_init(elphelmem_init);
+module_exit(elphelmem_exit);
+MODULE_LICENSE("GPL");
+
+