1 files changed, 284 insertions, 0 deletions
diff --git a/drivers/soc/sunxi/sunxi_sram.c b/drivers/soc/sunxi/sunxi_sram.c
new file mode 100644
index 000000000000..bc52670c8f4b
--- /dev/null
+++ b/drivers/soc/sunxi/sunxi_sram.c
@@ -0,0 +1,284 @@
+/*
+ * Allwinner SoCs SRAM Controller Driver
+ *
+ * Copyright (C) 2015 Maxime Ripard
+ *
+ * Author: Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+
+#include <linux/soc/sunxi/sunxi_sram.h>
+
+struct sunxi_sram_func {
+	char	*func;
+	u8	val;
+};
+
+struct sunxi_sram_data {
+	char			*name;
+	u8			reg;
+	u8			offset;
+	u8			width;
+	struct sunxi_sram_func	*func;
+	struct list_head	list;
+};
+
+struct sunxi_sram_desc {
+	struct sunxi_sram_data	data;
+	bool			claimed;
+};
+
+#define SUNXI_SRAM_MAP(_val, _func)				\
+	{							\
+		.func = _func,					\
+		.val = _val,					\
+	}
+
+#define SUNXI_SRAM_DATA(_name, _reg, _off, _width, ...)		\
+	{							\
+		.name = _name,					\
+		.reg = _reg,					\
+		.offset = _off,					\
+		.width = _width,				\
+		.func = (struct sunxi_sram_func[]){		\
+			__VA_ARGS__, { } },			\
+	}
+
+static struct sunxi_sram_desc sun4i_a10_sram_a3_a4 = {
+	.data	= SUNXI_SRAM_DATA("A3-A4", 0x4, 0x4, 2,
+				  SUNXI_SRAM_MAP(0, "cpu"),
+				  SUNXI_SRAM_MAP(1, "emac")),
+};
+
+static struct sunxi_sram_desc sun4i_a10_sram_d = {
+	.data	= SUNXI_SRAM_DATA("D", 0x4, 0x0, 1,
+				  SUNXI_SRAM_MAP(0, "cpu"),
+				  SUNXI_SRAM_MAP(1, "usb-otg")),
+};
+
+static const struct of_device_id sunxi_sram_dt_ids[] = {
+	{
+		.compatible	= "allwinner,sun4i-a10-sram-a3-a4",
+		.data		= &sun4i_a10_sram_a3_a4.data,
+	},
+	{
+		.compatible	= "allwinner,sun4i-a10-sram-d",
+		.data		= &sun4i_a10_sram_d.data,
+	},
+	{}
+};
+
+static struct device *sram_dev;
+static LIST_HEAD(claimed_sram);
+static DEFINE_SPINLOCK(sram_lock);
+static void __iomem *base;
+
+static int sunxi_sram_show(struct seq_file *s, void *data)
+{
+	struct device_node *sram_node, *section_node;
+	const struct sunxi_sram_data *sram_data;
+	const struct of_device_id *match;
+	struct sunxi_sram_func *func;
+	const __be32 *sram_addr_p, *section_addr_p;
+	u32 val;
+
+	seq_puts(s, "Allwinner sunXi SRAM\n");
+	seq_puts(s, "--------------------\n\n");
+
+	for_each_child_of_node(sram_dev->of_node, sram_node) {
+		sram_addr_p = of_get_address(sram_node, 0, NULL, NULL);
+
+		seq_printf(s, "sram@%08x\n",
+			   be32_to_cpu(*sram_addr_p));
+
+		for_each_child_of_node(sram_node, section_node) {
+			match = of_match_node(sunxi_sram_dt_ids, section_node);
+			if (!match)
+				continue;
+			sram_data = match->data;
+
+			section_addr_p = of_get_address(section_node, 0,
+							NULL, NULL);
+
+			seq_printf(s, "\tsection@%04x\t(%s)\n",
+				   be32_to_cpu(*section_addr_p),
+				   sram_data->name);
+
+			val = readl(base + sram_data->reg);
+			val >>= sram_data->offset;
+			val &= sram_data->width;
+
+			for (func = sram_data->func; func->func; func++) {
+				seq_printf(s, "\t\t%s%c\n", func->func,
+					   func->val == val ? '*' : ' ');
+			}
+		}
+
+		seq_puts(s, "\n");
+	}
+
+	return 0;
+}
+
+static int sunxi_sram_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, sunxi_sram_show, inode->i_private);
+}
+
+static const struct file_operations sunxi_sram_fops = {
+	.open = sunxi_sram_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static inline struct sunxi_sram_desc *to_sram_desc(const struct sunxi_sram_data *data)
+{
+	return container_of(data, struct sunxi_sram_desc, data);
+}
+
+static const struct sunxi_sram_data *sunxi_sram_of_parse(struct device_node *node,
+							 unsigned int *value)
+{
+	const struct of_device_id *match;
+	struct of_phandle_args args;
+	int ret;
+
+	ret = of_parse_phandle_with_fixed_args(node, "allwinner,sram", 1, 0,
+					       &args);
+	if (ret)
+		return ERR_PTR(ret);
+
+	if (!of_device_is_available(args.np)) {
+		ret = -EBUSY;
+		goto err;
+	}
+
+	if (value)
+		*value = args.args[0];
+
+	match = of_match_node(sunxi_sram_dt_ids, args.np);
+	if (!match) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	of_node_put(args.np);
+	return match->data;
+
+err:
+	of_node_put(args.np);
+	return ERR_PTR(ret);
+}
+
+int sunxi_sram_claim(struct device *dev)
+{
+	const struct sunxi_sram_data *sram_data;
+	struct sunxi_sram_desc *sram_desc;
+	unsigned int device;
+	u32 val, mask;
+
+	if (IS_ERR(base))
+		return -EPROBE_DEFER;
+
+	if (!dev || !dev->of_node)
+		return -EINVAL;
+
+	sram_data = sunxi_sram_of_parse(dev->of_node, &device);
+	if (IS_ERR(sram_data))
+		return PTR_ERR(sram_data);
+
+	sram_desc = to_sram_desc(sram_data);
+
+	spin_lock(&sram_lock);
+
+	if (sram_desc->claimed) {
+		spin_unlock(&sram_lock);
+		return -EBUSY;
+	}
+
+	mask = GENMASK(sram_data->offset + sram_data->width, sram_data->offset);
+	val = readl(base + sram_data->reg);
+	val &= ~mask;
+	writel(val | ((device << sram_data->offset) & mask),
+	       base + sram_data->reg);
+
+	spin_unlock(&sram_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(sunxi_sram_claim);
+
+int sunxi_sram_release(struct device *dev)
+{
+	const struct sunxi_sram_data *sram_data;
+	struct sunxi_sram_desc *sram_desc;
+
+	if (!dev || !dev->of_node)
+		return -EINVAL;
+
+	sram_data = sunxi_sram_of_parse(dev->of_node, NULL);
+	if (IS_ERR(sram_data))
+		return -EINVAL;
+
+	sram_desc = to_sram_desc(sram_data);
+
+	spin_lock(&sram_lock);
+	sram_desc->claimed = false;
+	spin_unlock(&sram_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(sunxi_sram_release);
+
+static int sunxi_sram_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct dentry *d;
+
+	sram_dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
+
+	d = debugfs_create_file("sram", S_IRUGO, NULL, NULL,
+				&sunxi_sram_fops);
+	if (!d)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static const struct of_device_id sunxi_sram_dt_match[] = {
+	{ .compatible = "allwinner,sun4i-a10-sram-controller" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, sunxi_sram_dt_match);
+
+static struct platform_driver sunxi_sram_driver = {
+	.driver = {
+		.name		= "sunxi-sram",
+		.of_match_table	= sunxi_sram_dt_match,
+	},
+	.probe	= sunxi_sram_probe,
+};
+module_platform_driver(sunxi_sram_driver);
+
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
+MODULE_DESCRIPTION("Allwinner sunXi SRAM Controller Driver");
+MODULE_LICENSE("GPL");