diff options
Diffstat (limited to 'drivers/reset/reset-intel-gw.c')
| -rw-r--r-- | drivers/reset/reset-intel-gw.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/drivers/reset/reset-intel-gw.c b/drivers/reset/reset-intel-gw.c new file mode 100644 index 0000000000..a5a01388ae --- /dev/null +++ b/drivers/reset/reset-intel-gw.c @@ -0,0 +1,262 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2019 Intel Corporation. + * Lei Chuanhua <Chuanhua.lei@intel.com> + */ + +#include <linux/bitfield.h> +#include <linux/init.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/reboot.h> +#include <linux/regmap.h> +#include <linux/reset-controller.h> + +#define RCU_RST_STAT 0x0024 +#define RCU_RST_REQ 0x0048 + +#define REG_OFFSET_MASK GENMASK(31, 16) +#define BIT_OFFSET_MASK GENMASK(15, 8) +#define STAT_BIT_OFFSET_MASK GENMASK(7, 0) + +#define to_reset_data(x) container_of(x, struct intel_reset_data, rcdev) + +struct intel_reset_soc { + bool legacy; + u32 reset_cell_count; +}; + +struct intel_reset_data { + struct reset_controller_dev rcdev; + struct notifier_block restart_nb; + const struct intel_reset_soc *soc_data; + struct regmap *regmap; + struct device *dev; + u32 reboot_id; +}; + +static const struct regmap_config intel_rcu_regmap_config = { + .name = "intel-reset", + .reg_bits = 32, + .reg_stride = 4, + .val_bits = 32, + .fast_io = true, +}; + +/* + * Reset status register offset relative to + * the reset control register(X) is X + 4 + */ +static u32 id_to_reg_and_bit_offsets(struct intel_reset_data *data, + unsigned long id, u32 *rst_req, + u32 *req_bit, u32 *stat_bit) +{ + *rst_req = FIELD_GET(REG_OFFSET_MASK, id); + *req_bit = FIELD_GET(BIT_OFFSET_MASK, id); + + if (data->soc_data->legacy) + *stat_bit = FIELD_GET(STAT_BIT_OFFSET_MASK, id); + else + *stat_bit = *req_bit; + + if (data->soc_data->legacy && *rst_req == RCU_RST_REQ) + return RCU_RST_STAT; + else + return *rst_req + 0x4; +} + +static int intel_set_clr_bits(struct intel_reset_data *data, unsigned long id, + bool set) +{ + u32 rst_req, req_bit, rst_stat, stat_bit, val; + int ret; + + rst_stat = id_to_reg_and_bit_offsets(data, id, &rst_req, + &req_bit, &stat_bit); + + val = set ? BIT(req_bit) : 0; + ret = regmap_update_bits(data->regmap, rst_req, BIT(req_bit), val); + if (ret) + return ret; + + return regmap_read_poll_timeout(data->regmap, rst_stat, val, + set == !!(val & BIT(stat_bit)), 20, + 200); +} + +static int intel_assert_device(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct intel_reset_data *data = to_reset_data(rcdev); + int ret; + + ret = intel_set_clr_bits(data, id, true); + if (ret) + dev_err(data->dev, "Reset assert failed %d\n", ret); + + return ret; +} + +static int intel_deassert_device(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct intel_reset_data *data = to_reset_data(rcdev); + int ret; + + ret = intel_set_clr_bits(data, id, false); + if (ret) + dev_err(data->dev, "Reset deassert failed %d\n", ret); + + return ret; +} + +static int intel_reset_status(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct intel_reset_data *data = to_reset_data(rcdev); + u32 rst_req, req_bit, rst_stat, stat_bit, val; + int ret; + + rst_stat = id_to_reg_and_bit_offsets(data, id, &rst_req, + &req_bit, &stat_bit); + ret = regmap_read(data->regmap, rst_stat, &val); + if (ret) + return ret; + + return !!(val & BIT(stat_bit)); +} + +static const struct reset_control_ops intel_reset_ops = { + .assert = intel_assert_device, + .deassert = intel_deassert_device, + .status = intel_reset_status, +}; + +static int intel_reset_xlate(struct reset_controller_dev *rcdev, + const struct of_phandle_args *spec) +{ + struct intel_reset_data *data = to_reset_data(rcdev); + u32 id; + + if (spec->args[1] > 31) + return -EINVAL; + + id = FIELD_PREP(REG_OFFSET_MASK, spec->args[0]); + id |= FIELD_PREP(BIT_OFFSET_MASK, spec->args[1]); + + if (data->soc_data->legacy) { + if (spec->args[2] > 31) + return -EINVAL; + + id |= FIELD_PREP(STAT_BIT_OFFSET_MASK, spec->args[2]); + } + + return id; +} + +static int intel_reset_restart_handler(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct intel_reset_data *reset_data; + + reset_data = container_of(nb, struct intel_reset_data, restart_nb); + intel_assert_device(&reset_data->rcdev, reset_data->reboot_id); + + return NOTIFY_DONE; +} + +static int intel_reset_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct device *dev = &pdev->dev; + struct intel_reset_data *data; + void __iomem *base; + u32 rb_id[3]; + int ret; + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->soc_data = of_device_get_match_data(dev); + if (!data->soc_data) + return -ENODEV; + + base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(base)) + return PTR_ERR(base); + + data->regmap = devm_regmap_init_mmio(dev, base, + &intel_rcu_regmap_config); + if (IS_ERR(data->regmap)) { + dev_err(dev, "regmap initialization failed\n"); + return PTR_ERR(data->regmap); + } + + ret = device_property_read_u32_array(dev, "intel,global-reset", rb_id, + data->soc_data->reset_cell_count); + if (ret) { + dev_err(dev, "Failed to get global reset offset!\n"); + return ret; + } + + data->dev = dev; + data->rcdev.of_node = np; + data->rcdev.owner = dev->driver->owner; + data->rcdev.ops = &intel_reset_ops; + data->rcdev.of_xlate = intel_reset_xlate; + data->rcdev.of_reset_n_cells = data->soc_data->reset_cell_count; + ret = devm_reset_controller_register(&pdev->dev, &data->rcdev); + if (ret) + return ret; + + data->reboot_id = FIELD_PREP(REG_OFFSET_MASK, rb_id[0]); + data->reboot_id |= FIELD_PREP(BIT_OFFSET_MASK, rb_id[1]); + + if (data->soc_data->legacy) + data->reboot_id |= FIELD_PREP(STAT_BIT_OFFSET_MASK, rb_id[2]); + + data->restart_nb.notifier_call = intel_reset_restart_handler; + data->restart_nb.priority = 128; + register_restart_handler(&data->restart_nb); + + return 0; +} + +static const struct intel_reset_soc xrx200_data = { + .legacy = true, + .reset_cell_count = 3, +}; + +static const struct intel_reset_soc lgm_data = { + .legacy = false, + .reset_cell_count = 2, +}; + +static const struct of_device_id intel_reset_match[] = { + { .compatible = "intel,rcu-lgm", .data = &lgm_data }, + { .compatible = "intel,rcu-xrx200", .data = &xrx200_data }, + {} +}; + +static struct platform_driver intel_reset_driver = { + .probe = intel_reset_probe, + .driver = { + .name = "intel-reset", + .of_match_table = intel_reset_match, + }, +}; + +static int __init intel_reset_init(void) +{ + return platform_driver_register(&intel_reset_driver); +} + +/* + * RCU is system core entity which is in Always On Domain whose clocks + * or resource initialization happens in system core initialization. + * Also, it is required for most of the platform or architecture + * specific devices to perform reset operation as part of initialization. + * So perform RCU as post core initialization. + */ +postcore_initcall(intel_reset_init); |