Re: [PATCH v2 20/23] counter: stm32-timer-cnt: Convert to new counter registration

From: Jonathan Cameron
Date: Tue Dec 28 2021 - 13:19:43 EST


On Mon, 27 Dec 2021 10:45:23 +0100
Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> wrote:

> This fixes device lifetime issues where it was possible to free a live
> struct device.
>
> Fixes: ad29937e206f ("counter: Add STM32 Timer quadrature encoder")
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>

Same basic form as all the others so easy to review (hopefully :)

Jonathan

> ---
> drivers/counter/stm32-timer-cnt.c | 30 ++++++++++++++++++------------
> 1 file changed, 18 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c
> index 4b05b198a8d8..5779ae7c73cf 100644
> --- a/drivers/counter/stm32-timer-cnt.c
> +++ b/drivers/counter/stm32-timer-cnt.c
> @@ -29,7 +29,6 @@ struct stm32_timer_regs {
> };
>
> struct stm32_timer_cnt {
> - struct counter_device counter;
> struct regmap *regmap;
> struct clk *clk;
> u32 max_arr;
> @@ -317,31 +316,38 @@ static int stm32_timer_cnt_probe(struct platform_device *pdev)
> struct stm32_timers *ddata = dev_get_drvdata(pdev->dev.parent);
> struct device *dev = &pdev->dev;
> struct stm32_timer_cnt *priv;
> + struct counter_device *counter;
> + int ret;
>
> if (IS_ERR_OR_NULL(ddata))
> return -EINVAL;
>
> - priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> - if (!priv)
> + counter = devm_counter_alloc(dev, sizeof(*priv));
> + if (!counter)
> return -ENOMEM;
>
> + priv = counter_priv(counter);
> +
> priv->regmap = ddata->regmap;
> priv->clk = ddata->clk;
> priv->max_arr = ddata->max_arr;
>
> - priv->counter.name = dev_name(dev);
> - priv->counter.parent = dev;
> - priv->counter.ops = &stm32_timer_cnt_ops;
> - priv->counter.counts = &stm32_counts;
> - priv->counter.num_counts = 1;
> - priv->counter.signals = stm32_signals;
> - priv->counter.num_signals = ARRAY_SIZE(stm32_signals);
> - priv->counter.priv = priv;
> + counter->name = dev_name(dev);
> + counter->parent = dev;
> + counter->ops = &stm32_timer_cnt_ops;
> + counter->counts = &stm32_counts;
> + counter->num_counts = 1;
> + counter->signals = stm32_signals;
> + counter->num_signals = ARRAY_SIZE(stm32_signals);
>
> platform_set_drvdata(pdev, priv);
>
> /* Register Counter device */
> - return devm_counter_register(dev, &priv->counter);
> + ret = devm_counter_add(dev, counter);
> + if (ret < 0)
> + dev_err_probe(dev, ret, "Failed to add counter\n");
> +
> + return ret;
> }
>
> static int __maybe_unused stm32_timer_cnt_suspend(struct device *dev)