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// SPDX-License-Identifier: GPL-2.0+
/* Microchip Sparx5 Switch Reset driver
*
* Copyright (c) 2020 Microchip Technology Inc. and its subsidiaries.
*
* The Sparx5 Chip Register Model can be browsed at this location:
* https://github.com/microchip-ung/sparx-5_reginfo
*/
#include <linux/mfd/syscon.h>
#include <linux/of_device.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/reset-controller.h>
#define PROTECT_REG 0x84
#define PROTECT_BIT BIT(10)
#define SOFT_RESET_REG 0x00
#define SOFT_RESET_BIT BIT(1)
struct mchp_reset_context {
struct regmap *cpu_ctrl;
struct regmap *gcb_ctrl;
struct reset_controller_dev rcdev;
};
static struct regmap_config sparx5_reset_regmap_config = {
.reg_bits = 32,
.val_bits = 32,
.reg_stride = 4,
};
static int sparx5_switch_reset(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct mchp_reset_context *ctx =
container_of(rcdev, struct mchp_reset_context, rcdev);
u32 val;
/* Make sure the core is PROTECTED from reset */
regmap_update_bits(ctx->cpu_ctrl, PROTECT_REG, PROTECT_BIT, PROTECT_BIT);
/* Start soft reset */
regmap_write(ctx->gcb_ctrl, SOFT_RESET_REG, SOFT_RESET_BIT);
/* Wait for soft reset done */
return regmap_read_poll_timeout(ctx->gcb_ctrl, SOFT_RESET_REG, val,
(val & SOFT_RESET_BIT) == 0,
1, 100);
}
static const struct reset_control_ops sparx5_reset_ops = {
.reset = sparx5_switch_reset,
};
static int mchp_sparx5_map_syscon(struct platform_device *pdev, char *name,
struct regmap **target)
{
struct device_node *syscon_np;
struct regmap *regmap;
int err;
syscon_np = of_parse_phandle(pdev->dev.of_node, name, 0);
if (!syscon_np)
return -ENODEV;
regmap = syscon_node_to_regmap(syscon_np);
of_node_put(syscon_np);
if (IS_ERR(regmap)) {
err = PTR_ERR(regmap);
dev_err(&pdev->dev, "No '%s' map: %d\n", name, err);
return err;
}
*target = regmap;
return 0;
}
static int mchp_sparx5_map_io(struct platform_device *pdev, int index,
struct regmap **target)
{
struct resource *res;
struct regmap *map;
void __iomem *mem;
mem = devm_platform_get_and_ioremap_resource(pdev, index, &res);
if (!mem) {
dev_err(&pdev->dev, "Could not map resource %d\n", index);
return -ENXIO;
}
sparx5_reset_regmap_config.name = res->name;
map = devm_regmap_init_mmio(&pdev->dev, mem, &sparx5_reset_regmap_config);
if (IS_ERR(map))
return PTR_ERR(map);
*target = map;
return 0;
}
static int mchp_sparx5_reset_probe(struct platform_device *pdev)
{
struct device_node *dn = pdev->dev.of_node;
struct mchp_reset_context *ctx;
int err;
ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
err = mchp_sparx5_map_syscon(pdev, "cpu-syscon", &ctx->cpu_ctrl);
if (err)
return err;
err = mchp_sparx5_map_io(pdev, 0, &ctx->gcb_ctrl);
if (err)
return err;
ctx->rcdev.owner = THIS_MODULE;
ctx->rcdev.nr_resets = 1;
ctx->rcdev.ops = &sparx5_reset_ops;
ctx->rcdev.of_node = dn;
return devm_reset_controller_register(&pdev->dev, &ctx->rcdev);
}
static const struct of_device_id mchp_sparx5_reset_of_match[] = {
{
.compatible = "microchip,sparx5-switch-reset",
},
{ }
};
static struct platform_driver mchp_sparx5_reset_driver = {
.probe = mchp_sparx5_reset_probe,
.driver = {
.name = "sparx5-switch-reset",
.of_match_table = mchp_sparx5_reset_of_match,
},
};
static int __init mchp_sparx5_reset_init(void)
{
return platform_driver_register(&mchp_sparx5_reset_driver);
}
postcore_initcall(mchp_sparx5_reset_init);
MODULE_DESCRIPTION("Microchip Sparx5 switch reset driver");
MODULE_AUTHOR("Steen Hegelund <steen.hegelund@microchip.com>");
MODULE_LICENSE("Dual MIT/GPL");
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