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clk: qcom: reset: Allow specifying custom reset delay

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[ Upstream commit 2cb8a39b6781ea23accd1fa93b3ad000d0948aec ]

The amount of time required between asserting and deasserting the reset
signal can vary depending on the involved hardware component. Sometimes
1 us might not be enough and a larger delay is necessary to conform to
the specifications.

Usually this is worked around in the consuming drivers, by replacing
reset_control_reset() with a sequence of reset_control_assert(), waiting
for a custom delay, followed by reset_control_deassert().

However, in some cases the driver making use of the reset is generic and
can be used with different reset controllers. In this case the reset
time requirement is better handled directly by the reset controller
driver.

Make this possible by adding an "udelay" field to the qcom_reset_map
that allows setting a different reset delay (in microseconds).

Signed-off-by: Stephan Gerhold <stephan.gerhold@kernkonzept.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20220706134132.3623415-4-stephan.gerhold@kernkonzept.com
Stable-dep-of: 349b5bed539b ("clk: qcom: ipq6018: fix networking resets")
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Stephan Gerhold 2022-07-06 15:41:29 +02:00 committed by Greg Kroah-Hartman
parent d87ef4e857
commit 35fd1a213f
2 changed files with 4 additions and 1 deletions
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4
drivers/clk/qcom/reset.c
View File

@ -13,8 +13,10 @@
static int qcom_reset(struct reset_controller_dev *rcdev, unsigned long id)
{
struct qcom_reset_controller *rst = to_qcom_reset_controller(rcdev);
rcdev->ops->assert(rcdev, id);
udelay(1);
udelay(rst->reset_map[id].udelay ?: 1); /* use 1 us as default */
rcdev->ops->deassert(rcdev, id);
return 0;
}

1
drivers/clk/qcom/reset.h
View File

@ -11,6 +11,7 @@
struct qcom_reset_map {
unsigned int reg;
u8 bit;
u8 udelay;
};
struct regmap;