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// SPDX-License-Identifier: GPL-2.0-only
/*
* ARM Integrator Logical Module bus driver
* Copyright (C) 2020 Linaro Ltd.
* Author: Linus Walleij <linus.walleij@linaro.org>
*
* See the device tree bindings for this block for more details on the
* hardware.
*/
#include <linux/module.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/bitops.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
/* All information about the connected logic modules are in here */
#define INTEGRATOR_SC_DEC_OFFSET 0x10
/* Base address for the expansion modules */
#define INTEGRATOR_AP_EXP_BASE 0xc0000000
#define INTEGRATOR_AP_EXP_STRIDE 0x10000000
static int integrator_lm_populate(int num, struct device *dev)
{
struct device_node *np = dev->of_node;
struct device_node *child;
u32 base;
int ret;
base = INTEGRATOR_AP_EXP_BASE + (num * INTEGRATOR_AP_EXP_STRIDE);
/* Walk over the child nodes and see what chipselects we use */
for_each_available_child_of_node(np, child) {
struct resource res;
ret = of_address_to_resource(child, 0, &res);
if (ret) {
dev_info(dev, "no valid address on child\n");
continue;
}
/* First populate the syscon then any devices */
if (res.start == base) {
dev_info(dev, "populate module @0x%08x from DT\n",
base);
ret = of_platform_default_populate(child, NULL, dev);
if (ret) {
dev_err(dev, "failed to populate module\n");
of_node_put(child);
return ret;
}
}
}
return 0;
}
static const struct of_device_id integrator_ap_syscon_match[] = {
{ .compatible = "arm,integrator-ap-syscon"},
{ },
};
static int integrator_ap_lm_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *syscon;
static struct regmap *map;
u32 val;
int ret;
int i;
/* Look up the system controller */
syscon = of_find_matching_node(NULL, integrator_ap_syscon_match);
if (!syscon) {
dev_err(dev,
"could not find Integrator/AP system controller\n");
return -ENODEV;
}
map = syscon_node_to_regmap(syscon);
of_node_put(syscon);
if (IS_ERR(map)) {
dev_err(dev,
"could not find Integrator/AP system controller\n");
return PTR_ERR(map);
}
ret = regmap_read(map, INTEGRATOR_SC_DEC_OFFSET, &val);
if (ret) {
dev_err(dev, "could not read from Integrator/AP syscon\n");
return ret;
}
/* Loop over the connected modules */
for (i = 0; i < 4; i++) {
if (!(val & BIT(4 + i)))
continue;
dev_info(dev, "detected module in slot %d\n", i);
ret = integrator_lm_populate(i, dev);
if (ret)
return ret;
}
return 0;
}
static const struct of_device_id integrator_ap_lm_match[] = {
{ .compatible = "arm,integrator-ap-lm"},
{ },
};
static struct platform_driver integrator_ap_lm_driver = {
.probe = integrator_ap_lm_probe,
.driver = {
.name = "integratorap-lm",
.of_match_table = integrator_ap_lm_match,
},
};
module_platform_driver(integrator_ap_lm_driver);
MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
MODULE_DESCRIPTION("Integrator AP Logical Module driver");
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