86 lines
2.7 KiB
Diff
86 lines
2.7 KiB
Diff
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From 66deff85fee24ecd7b0ffa2901711aa8f026fcfa Mon Sep 17 00:00:00 2001
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From: Maxime Ripard <maxime@cerno.tech>
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Date: Tue, 28 Jan 2020 16:22:20 +0100
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Subject: [PATCH] reset: simple: Add reset callback
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The reset-simple code lacks a reset callback that is still pretty easy to
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implement. The only real thing to consider is the delay needed for a device
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to be reset, so let's expose that as part of the reset-simple driver data.
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Cc: Philipp Zabel <p.zabel@pengutronix.de>
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Signed-off-by: Maxime Ripard <maxime@cerno.tech>
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---
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drivers/reset/reset-simple.c | 24 ++++++++++++++++++++++++
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include/linux/reset/reset-simple.h | 6 ++++++
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2 files changed, 30 insertions(+)
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--- a/drivers/reset/reset-simple.c
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+++ b/drivers/reset/reset-simple.c
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@@ -11,6 +11,7 @@
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* Maxime Ripard <maxime.ripard@free-electrons.com>
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*/
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+#include <linux/delay.h>
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/io.h>
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@@ -63,6 +64,28 @@ static int reset_simple_deassert(struct
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return reset_simple_update(rcdev, id, false);
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}
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+static int reset_simple_reset(struct reset_controller_dev *rcdev,
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+ unsigned long id)
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+{
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+ struct reset_simple_data *data = to_reset_simple_data(rcdev);
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+ int ret;
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+
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+ if (!data->reset_us)
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+ return -ENOTSUPP;
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+
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+ ret = reset_simple_assert(rcdev, id);
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+ if (ret)
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+ return ret;
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+
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+ usleep_range(data->reset_us, data->reset_us * 2);
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+
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+ ret = reset_simple_deassert(rcdev, id);
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+ if (ret)
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+ return ret;
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+
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+ return 0;
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+}
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+
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static int reset_simple_status(struct reset_controller_dev *rcdev,
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unsigned long id)
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{
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@@ -80,6 +103,7 @@ static int reset_simple_status(struct re
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const struct reset_control_ops reset_simple_ops = {
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.assert = reset_simple_assert,
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.deassert = reset_simple_deassert,
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+ .reset = reset_simple_reset,
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.status = reset_simple_status,
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};
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EXPORT_SYMBOL_GPL(reset_simple_ops);
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--- a/include/linux/reset/reset-simple.h
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+++ b/include/linux/reset/reset-simple.h
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@@ -27,6 +27,11 @@
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* @status_active_low: if true, bits read back as cleared while the reset is
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* asserted. Otherwise, bits read back as set while the
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* reset is asserted.
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+ * @reset_us: Minimum delay in microseconds needed that needs to be
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+ * waited for between an assert and a deassert to reset the
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+ * device. If multiple consumers with different delay
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+ * requirements are connected to this controller, it must
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+ * be the largest minimum delay.
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*/
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struct reset_simple_data {
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spinlock_t lock;
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@@ -34,6 +39,7 @@ struct reset_simple_data {
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struct reset_controller_dev rcdev;
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bool active_low;
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bool status_active_low;
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+ unsigned int reset_us;
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};
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extern const struct reset_control_ops reset_simple_ops;
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