From 3962c24f2d14e8a7f8a23f56b7ce320523947342 Mon Sep 17 00:00:00 2001 From: "Viorel Suman (OSS)" Date: Wed, 11 Mar 2026 14:33:09 +0200 Subject: [PATCH] pwm: imx-tpm: Count the number of enabled channels in probe MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On a soft reset TPM PWM IP may preserve its internal state from previous runtime, therefore on a subsequent OS boot and driver probe "enable_count" value and TPM PWM IP internal channels "enabled" states may get unaligned. In consequence on a suspend/resume cycle the call "if (--tpm->enable_count == 0)" may lead to "enable_count" overflow the system being blocked from entering suspend due to: if (tpm->enable_count > 0) return -EBUSY; Fix the problem by counting the enabled channels in probe function. Signed-off-by: Viorel Suman (OSS) Fixes: 738a1cfec2ed ("pwm: Add i.MX TPM PWM driver support") Link: https://patch.msgid.link/20260311123309.348904-1-viorel.suman@oss.nxp.com Cc: stable@vger.kernel.org Signed-off-by: Uwe Kleine-König --- drivers/pwm/pwm-imx-tpm.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/pwm/pwm-imx-tpm.c b/drivers/pwm/pwm-imx-tpm.c index 5b399de16d60..80fdb3303400 100644 --- a/drivers/pwm/pwm-imx-tpm.c +++ b/drivers/pwm/pwm-imx-tpm.c @@ -352,7 +352,7 @@ static int pwm_imx_tpm_probe(struct platform_device *pdev) struct clk *clk; void __iomem *base; int ret; - unsigned int npwm; + unsigned int i, npwm; u32 val; base = devm_platform_ioremap_resource(pdev, 0); @@ -382,6 +382,13 @@ static int pwm_imx_tpm_probe(struct platform_device *pdev) mutex_init(&tpm->lock); + /* count the enabled channels */ + for (i = 0; i < npwm; ++i) { + val = readl(base + PWM_IMX_TPM_CnSC(i)); + if (FIELD_GET(PWM_IMX_TPM_CnSC_ELS, val)) + ++tpm->enable_count; + } + ret = devm_pwmchip_add(&pdev->dev, chip); if (ret) return dev_err_probe(&pdev->dev, ret, "failed to add PWM chip\n");