| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | From 66deff85fee24ecd7b0ffa2901711aa8f026fcfa Mon Sep 17 00:00:00 2001 |
| 2 | From: Maxime Ripard <maxime@cerno.tech> |
| 3 | Date: Tue, 28 Jan 2020 16:22:20 +0100 |
| 4 | Subject: [PATCH] reset: simple: Add reset callback |
| 5 | |
| 6 | The reset-simple code lacks a reset callback that is still pretty easy to |
| 7 | implement. The only real thing to consider is the delay needed for a device |
| 8 | to be reset, so let's expose that as part of the reset-simple driver data. |
| 9 | |
| 10 | Cc: Philipp Zabel <p.zabel@pengutronix.de> |
| 11 | Signed-off-by: Maxime Ripard <maxime@cerno.tech> |
| 12 | --- |
| 13 | drivers/reset/reset-simple.c | 24 ++++++++++++++++++++++++ |
| 14 | include/linux/reset/reset-simple.h | 6 ++++++ |
| 15 | 2 files changed, 30 insertions(+) |
| 16 | |
| 17 | --- a/drivers/reset/reset-simple.c |
| 18 | +++ b/drivers/reset/reset-simple.c |
| 19 | @@ -11,6 +11,7 @@ |
| 20 | * Maxime Ripard <maxime.ripard@free-electrons.com> |
| 21 | */ |
| 22 | |
| 23 | +#include <linux/delay.h> |
| 24 | #include <linux/device.h> |
| 25 | #include <linux/err.h> |
| 26 | #include <linux/io.h> |
| 27 | @@ -63,6 +64,28 @@ static int reset_simple_deassert(struct |
| 28 | return reset_simple_update(rcdev, id, false); |
| 29 | } |
| 30 | |
| 31 | +static int reset_simple_reset(struct reset_controller_dev *rcdev, |
| 32 | + unsigned long id) |
| 33 | +{ |
| 34 | + struct reset_simple_data *data = to_reset_simple_data(rcdev); |
| 35 | + int ret; |
| 36 | + |
| 37 | + if (!data->reset_us) |
| 38 | + return -ENOTSUPP; |
| 39 | + |
| 40 | + ret = reset_simple_assert(rcdev, id); |
| 41 | + if (ret) |
| 42 | + return ret; |
| 43 | + |
| 44 | + usleep_range(data->reset_us, data->reset_us * 2); |
| 45 | + |
| 46 | + ret = reset_simple_deassert(rcdev, id); |
| 47 | + if (ret) |
| 48 | + return ret; |
| 49 | + |
| 50 | + return 0; |
| 51 | +} |
| 52 | + |
| 53 | static int reset_simple_status(struct reset_controller_dev *rcdev, |
| 54 | unsigned long id) |
| 55 | { |
| 56 | @@ -80,6 +103,7 @@ static int reset_simple_status(struct re |
| 57 | const struct reset_control_ops reset_simple_ops = { |
| 58 | .assert = reset_simple_assert, |
| 59 | .deassert = reset_simple_deassert, |
| 60 | + .reset = reset_simple_reset, |
| 61 | .status = reset_simple_status, |
| 62 | }; |
| 63 | EXPORT_SYMBOL_GPL(reset_simple_ops); |
| 64 | --- a/include/linux/reset/reset-simple.h |
| 65 | +++ b/include/linux/reset/reset-simple.h |
| 66 | @@ -27,6 +27,11 @@ |
| 67 | * @status_active_low: if true, bits read back as cleared while the reset is |
| 68 | * asserted. Otherwise, bits read back as set while the |
| 69 | * reset is asserted. |
| 70 | + * @reset_us: Minimum delay in microseconds needed that needs to be |
| 71 | + * waited for between an assert and a deassert to reset the |
| 72 | + * device. If multiple consumers with different delay |
| 73 | + * requirements are connected to this controller, it must |
| 74 | + * be the largest minimum delay. |
| 75 | */ |
| 76 | struct reset_simple_data { |
| 77 | spinlock_t lock; |
| 78 | @@ -34,6 +39,7 @@ struct reset_simple_data { |
| 79 | struct reset_controller_dev rcdev; |
| 80 | bool active_low; |
| 81 | bool status_active_low; |
| 82 | + unsigned int reset_us; |
| 83 | }; |
| 84 | |
| 85 | extern const struct reset_control_ops reset_simple_ops; |