From 9357b04624013294e4204b1a837d0a611b9048c3 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Wed, 27 May 2020 17:47:31 +0200 Subject: reset: Move reset-simple header out of drivers/reset The reset-simple code can be useful for drivers outside of drivers/reset that have a few reset controls as part of their features. Let's move it to include/linux/reset. Reviewed-by: Philipp Zabel Signed-off-by: Maxime Ripard Signed-off-by: Philipp Zabel --- include/linux/reset/reset-simple.h | 41 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 include/linux/reset/reset-simple.h (limited to 'include/linux/reset/reset-simple.h') diff --git a/include/linux/reset/reset-simple.h b/include/linux/reset/reset-simple.h new file mode 100644 index 000000000000..08ccb25a55e6 --- /dev/null +++ b/include/linux/reset/reset-simple.h @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Simple Reset Controller ops + * + * Based on Allwinner SoCs Reset Controller driver + * + * Copyright 2013 Maxime Ripard + * + * Maxime Ripard + */ + +#ifndef __RESET_SIMPLE_H__ +#define __RESET_SIMPLE_H__ + +#include +#include +#include + +/** + * struct reset_simple_data - driver data for simple reset controllers + * @lock: spinlock to protect registers during read-modify-write cycles + * @membase: memory mapped I/O register range + * @rcdev: reset controller device base structure + * @active_low: if true, bits are cleared to assert the reset. Otherwise, bits + * are set to assert the reset. Note that this says nothing about + * the voltage level of the actual reset line. + * @status_active_low: if true, bits read back as cleared while the reset is + * asserted. Otherwise, bits read back as set while the + * reset is asserted. + */ +struct reset_simple_data { + spinlock_t lock; + void __iomem *membase; + struct reset_controller_dev rcdev; + bool active_low; + bool status_active_low; +}; + +extern const struct reset_control_ops reset_simple_ops; + +#endif /* __RESET_SIMPLE_H__ */ -- cgit v1.2.3 From a9701376ed0fb61a5be4bb438daf26bd9cfa24b5 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Wed, 27 May 2020 17:47:32 +0200 Subject: reset: simple: Add reset callback The reset-simple code lacks a reset callback that is still pretty easy to implement. The only real thing to consider is the delay needed for a device to be reset, so let's expose that as part of the reset-simple driver data. Reviewed-by: Philipp Zabel Signed-off-by: Maxime Ripard Signed-off-by: Philipp Zabel --- drivers/reset/reset-simple.c | 20 ++++++++++++++++++++ include/linux/reset/reset-simple.h | 7 +++++++ 2 files changed, 27 insertions(+) (limited to 'include/linux/reset/reset-simple.h') diff --git a/drivers/reset/reset-simple.c b/drivers/reset/reset-simple.c index c854aa351640..e066614818a3 100644 --- a/drivers/reset/reset-simple.c +++ b/drivers/reset/reset-simple.c @@ -11,6 +11,7 @@ * Maxime Ripard */ +#include #include #include #include @@ -63,6 +64,24 @@ static int reset_simple_deassert(struct reset_controller_dev *rcdev, return reset_simple_update(rcdev, id, false); } +static int reset_simple_reset(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct reset_simple_data *data = to_reset_simple_data(rcdev); + int ret; + + if (!data->reset_us) + return -ENOTSUPP; + + ret = reset_simple_assert(rcdev, id); + if (ret) + return ret; + + usleep_range(data->reset_us, data->reset_us * 2); + + return reset_simple_deassert(rcdev, id); +} + static int reset_simple_status(struct reset_controller_dev *rcdev, unsigned long id) { @@ -80,6 +99,7 @@ static int reset_simple_status(struct reset_controller_dev *rcdev, const struct reset_control_ops reset_simple_ops = { .assert = reset_simple_assert, .deassert = reset_simple_deassert, + .reset = reset_simple_reset, .status = reset_simple_status, }; EXPORT_SYMBOL_GPL(reset_simple_ops); diff --git a/include/linux/reset/reset-simple.h b/include/linux/reset/reset-simple.h index 08ccb25a55e6..c3e44f45b0f7 100644 --- a/include/linux/reset/reset-simple.h +++ b/include/linux/reset/reset-simple.h @@ -27,6 +27,12 @@ * @status_active_low: if true, bits read back as cleared while the reset is * asserted. Otherwise, bits read back as set while the * reset is asserted. + * @reset_us: Minimum delay in microseconds needed that needs to be + * waited for between an assert and a deassert to reset the + * device. If multiple consumers with different delay + * requirements are connected to this controller, it must + * be the largest minimum delay. 0 means that such a delay is + * unknown and the reset operation is unsupported. */ struct reset_simple_data { spinlock_t lock; @@ -34,6 +40,7 @@ struct reset_simple_data { struct reset_controller_dev rcdev; bool active_low; bool status_active_low; + unsigned int reset_us; }; extern const struct reset_control_ops reset_simple_ops; -- cgit v1.2.3