diff options
Diffstat (limited to 'drivers/reset/starfive/reset-starfive-jh7100-audio.c')
-rw-r--r-- | drivers/reset/starfive/reset-starfive-jh7100-audio.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/drivers/reset/starfive/reset-starfive-jh7100-audio.c b/drivers/reset/starfive/reset-starfive-jh7100-audio.c new file mode 100644 index 000000000000..44ffef634fed --- /dev/null +++ b/drivers/reset/starfive/reset-starfive-jh7100-audio.c @@ -0,0 +1,66 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Audio reset driver for the StarFive JH7100 SoC + * + * Copyright (C) 2021 Emil Renner Berthing <kernel@esmil.dk> + */ + +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/platform_device.h> + +#include "reset-starfive-jh71x0.h" + +#include <dt-bindings/reset/starfive-jh7100-audio.h> + +/* register offsets */ +#define JH7100_AUDRST_ASSERT0 0x00 +#define JH7100_AUDRST_STATUS0 0x04 + +/* + * Writing a 1 to the n'th bit of the ASSERT register asserts + * line n, and writing a 0 deasserts the same line. + * Most reset lines have their status inverted so a 0 bit in the STATUS + * register means the line is asserted and a 1 means it's deasserted. A few + * lines don't though, so store the expected value of the status registers when + * all lines are asserted. + */ +static const u32 jh7100_audrst_asserted[1] = { + BIT(JH7100_AUDRST_USB_AXI) | + BIT(JH7100_AUDRST_USB_PWRUP_RST_N) | + BIT(JH7100_AUDRST_USB_PONRST) +}; + +static int jh7100_audrst_probe(struct platform_device *pdev) +{ + void __iomem *base = devm_platform_ioremap_resource(pdev, 0); + + if (IS_ERR(base)) + return PTR_ERR(base); + + return reset_starfive_jh71x0_register(&pdev->dev, pdev->dev.of_node, + base + JH7100_AUDRST_ASSERT0, + base + JH7100_AUDRST_STATUS0, + jh7100_audrst_asserted, + JH7100_AUDRSTN_END, + THIS_MODULE); +} + +static const struct of_device_id jh7100_audrst_dt_ids[] = { + { .compatible = "starfive,jh7100-audrst" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, jh7100_audrst_dt_ids); + +static struct platform_driver jh7100_audrst_driver = { + .probe = jh7100_audrst_probe, + .driver = { + .name = "jh7100-reset-audio", + .of_match_table = jh7100_audrst_dt_ids, + }, +}; +module_platform_driver(jh7100_audrst_driver); + +MODULE_AUTHOR("Emil Renner Berthing"); +MODULE_DESCRIPTION("StarFive JH7100 audio reset driver"); +MODULE_LICENSE("GPL"); |