From: Fancy Fang <chen.fang@nxp.com>
Date: Fri, 5 May 2023 06:58:39 +0000 (+0800)
Subject: pwm: imx-tpm: force 'real_period' to be zero in suspend
X-Git-Tag: v5.4.251~170
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5375c024f8aed7bc13b415c882e115dbef4e4d44;p=thirdparty%2Fkernel%2Fstable.git

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@nxp.com>
Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Fixes: 738a1cfec2ed ("pwm: Add i.MX TPM PWM driver support")
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

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;