This is a note to let you know that I've just added the patch titled
pwm: imx-tpm: force 'real_period' to be zero in suspend
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pwm-imx-tpm-force-real_period-to-be-zero-in-suspend.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a92b7ac7410e183bb2f6e41d0f3746d835de0c68
Author: Fancy Fang <chen.fang@xxxxxxx>
Date: Fri May 5 14:58:39 2023 +0800
pwm: imx-tpm: force 'real_period' to be zero in suspend
[ Upstream commit 661dfb7f46298e53f6c3deaa772fa527aae86193 ]
During suspend, all the tpm registers will lose values.
So the 'real_period' value of struct 'imx_tpm_pwm_chip'
should be forced to be zero to force the period update
code can be executed after system resume back.
Signed-off-by: Fancy Fang <chen.fang@xxxxxxx>
Signed-off-by: Clark Wang <xiaoning.wang@xxxxxxx>
Acked-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
Fixes: 738a1cfec2ed ("pwm: Add i.MX TPM PWM driver support")
Signed-off-by: Thierry Reding <thierry.reding@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/pwm/pwm-imx-tpm.c b/drivers/pwm/pwm-imx-tpm.c
index 9145f61606497..85aad55b7a8f0 100644
--- a/drivers/pwm/pwm-imx-tpm.c
+++ b/drivers/pwm/pwm-imx-tpm.c
@@ -405,6 +405,13 @@ static int __maybe_unused pwm_imx_tpm_suspend(struct device *dev)
if (tpm->enable_count > 0)
return -EBUSY;
+ /*
+ * Force 'real_period' to be zero to force period update code
+ * can be executed after system resume back, since suspend causes
+ * the period related registers to become their reset values.
+ */
+ tpm->real_period = 0;
+
clk_disable_unprepare(tpm->clk);
return 0;
