--- /dev/null
+/*
+ * 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");
projects / cascardo / linux.git / blobdiff