/* * Copyright Intel Corporation (C) 2017. All Rights Reserved * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * * You should have received a copy of the GNU General Public License along with * this program. If not, see <http://www.gnu.org/licenses/>. * * Reset driver for Altera Arria10 MAX5 System Resource Chip * * Adapted from reset-socfpga.c */ #include <linux/err.h> #include <linux/mfd/altera-a10sr.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/reset-controller.h> #include <dt-bindings/reset/altr,rst-mgr-a10sr.h> struct a10sr_reset { struct reset_controller_dev rcdev; struct regmap *regmap; }; static inline struct a10sr_reset *to_a10sr_rst(struct reset_controller_dev *rc) { return container_of(rc, struct a10sr_reset, rcdev); } static inline int a10sr_reset_shift(unsigned long id) { switch (id) { case A10SR_RESET_ENET_HPS: return 1; case A10SR_RESET_PCIE: case A10SR_RESET_FILE: case A10SR_RESET_BQSPI: case A10SR_RESET_USB: return id + 11; default: return -EINVAL; } } static int a10sr_reset_update(struct reset_controller_dev *rcdev, unsigned long id, bool assert) { struct a10sr_reset *a10r = to_a10sr_rst(rcdev); int offset = a10sr_reset_shift(id); u8 mask = ALTR_A10SR_REG_BIT_MASK(offset); int index = ALTR_A10SR_HPS_RST_REG + ALTR_A10SR_REG_OFFSET(offset); return regmap_update_bits(a10r->regmap, index, mask, assert ? 0 : mask); } static int a10sr_reset_assert(struct reset_controller_dev *rcdev, unsigned long id) { return a10sr_reset_update(rcdev, id, true); } static int a10sr_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id) { return a10sr_reset_update(rcdev, id, false); } static int a10sr_reset_status(struct reset_controller_dev *rcdev, unsigned long id) { int ret; struct a10sr_reset *a10r = to_a10sr_rst(rcdev); int offset = a10sr_reset_shift(id); u8 mask = ALTR_A10SR_REG_BIT_MASK(offset); int index = ALTR_A10SR_HPS_RST_REG + ALTR_A10SR_REG_OFFSET(offset); unsigned int value; ret = regmap_read(a10r->regmap, index, &value); if (ret < 0) return ret; return !!(value & mask); } static const struct reset_control_ops a10sr_reset_ops = { .assert = a10sr_reset_assert, .deassert = a10sr_reset_deassert, .status = a10sr_reset_status, }; static int a10sr_reset_probe(struct platform_device *pdev) { struct altr_a10sr *a10sr = dev_get_drvdata(pdev->dev.parent); struct a10sr_reset *a10r; a10r = devm_kzalloc(&pdev->dev, sizeof(struct a10sr_reset), GFP_KERNEL); if (!a10r) return -ENOMEM; a10r->rcdev.owner = THIS_MODULE; a10r->rcdev.nr_resets = A10SR_RESET_NUM; a10r->rcdev.ops = &a10sr_reset_ops; a10r->rcdev.of_node = pdev->dev.of_node; a10r->regmap = a10sr->regmap; platform_set_drvdata(pdev, a10r); return devm_reset_controller_register(&pdev->dev, &a10r->rcdev); } static const struct of_device_id a10sr_reset_of_match[] = { { .compatible = "altr,a10sr-reset" }, { }, }; MODULE_DEVICE_TABLE(of, a10sr_reset_of_match); static struct platform_driver a10sr_reset_driver = { .probe = a10sr_reset_probe, .driver = { .name = "altr_a10sr_reset", }, }; module_platform_driver(a10sr_reset_driver); MODULE_AUTHOR("Thor Thayer <thor.thayer@linux.intel.com>"); MODULE_DESCRIPTION("Altera Arria10 System Resource Reset Controller Driver"); MODULE_LICENSE("GPL v2");