From: Fancy Fang chen.fang@nxp.com
[ 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 --- drivers/pwm/pwm-imx-tpm.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/pwm/pwm-imx-tpm.c b/drivers/pwm/pwm-imx-tpm.c index ed1aad96fff04..318dc0be974b4 100644 --- a/drivers/pwm/pwm-imx-tpm.c +++ b/drivers/pwm/pwm-imx-tpm.c @@ -399,6 +399,13 @@ 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;