diff options
| author | Viorel Suman (OSS) <viorel.suman@oss.nxp.com> | 2026-03-11 15:33:09 +0300 |
|---|---|---|
| committer | Uwe Kleine-König <ukleinek@kernel.org> | 2026-03-13 11:56:28 +0300 |
| commit | 3962c24f2d14e8a7f8a23f56b7ce320523947342 (patch) | |
| tree | 60d3d53169d5b61fc8896946257687d6f426ec05 | |
| parent | 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f (diff) | |
| download | linux-3962c24f2d14e8a7f8a23f56b7ce320523947342.tar.xz | |
pwm: imx-tpm: Count the number of enabled channels in probe
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) <viorel.suman@oss.nxp.com>
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 <ukleinek@kernel.org>
| -rw-r--r-- | drivers/pwm/pwm-imx-tpm.c | 9 |
1 files changed, 8 insertions, 1 deletions
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"); |