diff options
Diffstat (limited to 'drivers/reset/reset-pistachio.c')
| -rw-r--r-- | drivers/reset/reset-pistachio.c | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/drivers/reset/reset-pistachio.c b/drivers/reset/reset-pistachio.c new file mode 100644 index 000000000..11d651b44 --- /dev/null +++ b/drivers/reset/reset-pistachio.c @@ -0,0 +1,139 @@ +/* + * Pistachio SoC Reset Controller driver + * + * Copyright (C) 2015 Imagination Technologies Ltd. + * + * Author: Damien Horsley <Damien.Horsley@imgtec.com> + * + * 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. + */ + +#include <linux/init.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/reset-controller.h> +#include <linux/slab.h> +#include <linux/mfd/syscon.h> + +#include <dt-bindings/reset/pistachio-resets.h> + +#define PISTACHIO_SOFT_RESET 0 + +struct pistachio_reset_data { + struct reset_controller_dev rcdev; + struct regmap *periph_regs; +}; + +static inline int pistachio_reset_shift(unsigned long id) +{ + switch (id) { + case PISTACHIO_RESET_I2C0: + case PISTACHIO_RESET_I2C1: + case PISTACHIO_RESET_I2C2: + case PISTACHIO_RESET_I2C3: + case PISTACHIO_RESET_I2S_IN: + case PISTACHIO_RESET_PRL_OUT: + case PISTACHIO_RESET_SPDIF_OUT: + case PISTACHIO_RESET_SPI: + case PISTACHIO_RESET_PWM_PDM: + case PISTACHIO_RESET_UART0: + case PISTACHIO_RESET_UART1: + case PISTACHIO_RESET_QSPI: + case PISTACHIO_RESET_MDC: + case PISTACHIO_RESET_SDHOST: + case PISTACHIO_RESET_ETHERNET: + case PISTACHIO_RESET_IR: + case PISTACHIO_RESET_HASH: + case PISTACHIO_RESET_TIMER: + return id; + case PISTACHIO_RESET_I2S_OUT: + case PISTACHIO_RESET_SPDIF_IN: + case PISTACHIO_RESET_EVT: + return id + 6; + case PISTACHIO_RESET_USB_H: + case PISTACHIO_RESET_USB_PR: + case PISTACHIO_RESET_USB_PHY_PR: + case PISTACHIO_RESET_USB_PHY_PON: + return id + 7; + default: + return -EINVAL; + } +} + +static int pistachio_reset_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct pistachio_reset_data *rd; + u32 mask; + int shift; + + rd = container_of(rcdev, struct pistachio_reset_data, rcdev); + shift = pistachio_reset_shift(id); + if (shift < 0) + return shift; + mask = BIT(shift); + + return regmap_update_bits(rd->periph_regs, PISTACHIO_SOFT_RESET, + mask, mask); +} + +static int pistachio_reset_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct pistachio_reset_data *rd; + u32 mask; + int shift; + + rd = container_of(rcdev, struct pistachio_reset_data, rcdev); + shift = pistachio_reset_shift(id); + if (shift < 0) + return shift; + mask = BIT(shift); + + return regmap_update_bits(rd->periph_regs, PISTACHIO_SOFT_RESET, + mask, 0); +} + +static const struct reset_control_ops pistachio_reset_ops = { + .assert = pistachio_reset_assert, + .deassert = pistachio_reset_deassert, +}; + +static int pistachio_reset_probe(struct platform_device *pdev) +{ + struct pistachio_reset_data *rd; + struct device *dev = &pdev->dev; + struct device_node *np = pdev->dev.of_node; + + rd = devm_kzalloc(dev, sizeof(*rd), GFP_KERNEL); + if (!rd) + return -ENOMEM; + + rd->periph_regs = syscon_node_to_regmap(np->parent); + if (IS_ERR(rd->periph_regs)) + return PTR_ERR(rd->periph_regs); + + rd->rcdev.owner = THIS_MODULE; + rd->rcdev.nr_resets = PISTACHIO_RESET_MAX + 1; + rd->rcdev.ops = &pistachio_reset_ops; + rd->rcdev.of_node = np; + + return devm_reset_controller_register(dev, &rd->rcdev); +} + +static const struct of_device_id pistachio_reset_dt_ids[] = { + { .compatible = "img,pistachio-reset", }, + { /* sentinel */ }, +}; + +static struct platform_driver pistachio_reset_driver = { + .probe = pistachio_reset_probe, + .driver = { + .name = "pistachio-reset", + .of_match_table = pistachio_reset_dt_ids, + }, +}; +builtin_platform_driver(pistachio_reset_driver); |