diff options
Diffstat (limited to 'drivers/reset/reset-microchip-sparx5.c')
| -rw-r--r-- | drivers/reset/reset-microchip-sparx5.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/drivers/reset/reset-microchip-sparx5.c b/drivers/reset/reset-microchip-sparx5.c new file mode 100644 index 000000000..f3528dd1d --- /dev/null +++ b/drivers/reset/reset-microchip-sparx5.c @@ -0,0 +1,182 @@ +// 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> + +struct reset_props { + u32 protect_reg; + u32 protect_bit; + u32 reset_reg; + u32 reset_bit; +}; + +struct mchp_reset_context { + struct regmap *cpu_ctrl; + struct regmap *gcb_ctrl; + struct reset_controller_dev rcdev; + const struct reset_props *props; +}; + +static struct regmap_config sparx5_reset_regmap_config = { + .reg_bits = 32, + .val_bits = 32, + .reg_stride = 4, +}; + +static int sparx5_switch_reset(struct mchp_reset_context *ctx) +{ + u32 val; + + /* Make sure the core is PROTECTED from reset */ + regmap_update_bits(ctx->cpu_ctrl, ctx->props->protect_reg, + ctx->props->protect_bit, ctx->props->protect_bit); + + /* Start soft reset */ + regmap_write(ctx->gcb_ctrl, ctx->props->reset_reg, + ctx->props->reset_bit); + + /* Wait for soft reset done */ + return regmap_read_poll_timeout(ctx->gcb_ctrl, ctx->props->reset_reg, val, + (val & ctx->props->reset_bit) == 0, + 1, 100); +} + +static int sparx5_reset_noop(struct reset_controller_dev *rcdev, + unsigned long id) +{ + return 0; +} + +static const struct reset_control_ops sparx5_reset_ops = { + .reset = sparx5_reset_noop, +}; + +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 (IS_ERR(mem)) { + dev_err(&pdev->dev, "Could not map resource %d\n", index); + return PTR_ERR(mem); + } + 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; + ctx->props = device_get_match_data(&pdev->dev); + + /* Issue the reset very early, our actual reset callback is a noop. */ + err = sparx5_switch_reset(ctx); + if (err) + return err; + + return devm_reset_controller_register(&pdev->dev, &ctx->rcdev); +} + +static const struct reset_props reset_props_sparx5 = { + .protect_reg = 0x84, + .protect_bit = BIT(10), + .reset_reg = 0x0, + .reset_bit = BIT(1), +}; + +static const struct reset_props reset_props_lan966x = { + .protect_reg = 0x88, + .protect_bit = BIT(5), + .reset_reg = 0x0, + .reset_bit = BIT(1), +}; + +static const struct of_device_id mchp_sparx5_reset_of_match[] = { + { + .compatible = "microchip,sparx5-switch-reset", + .data = &reset_props_sparx5, + }, { + .compatible = "microchip,lan966x-switch-reset", + .data = &reset_props_lan966x, + }, + { } +}; + +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); +} + +/* + * Because this is a global reset, keep this postcore_initcall() to issue the + * reset as early as possible during the kernel startup. + */ +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"); |