linux/drivers/soc/sunxi/sunxi_sram.c

285 lines
6.2 KiB
C

/*
* 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");