diff options
Diffstat (limited to 'drivers/reset/reset-a10sr.c')
| -rw-r--r-- | drivers/reset/reset-a10sr.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/drivers/reset/reset-a10sr.c b/drivers/reset/reset-a10sr.c new file mode 100644 index 000000000000..37496bd27fa2 --- /dev/null +++ b/drivers/reset/reset-a10sr.c @@ -0,0 +1,138 @@ +/* + * 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"); |