Hi Andy,
Sorry for late reply due to my business trip.
On 六, 6月 17, 2017 at 08:18:49下午 +0300, Andy Shevchenko wrote:
> On Thu, Jun 15, 2017 at 2:30 PM, Baolin Wang <baolin.wang@xxxxxxxxxxxxxx> wrote:
> > This patch adds the I2C controller driver for Spreadtrum platform.
>
>
> > + i2c_dev->irq = platform_get_irq(pdev, 0);
> > + if (i2c_dev->irq < 0) {
> > + dev_err(&pdev->dev, "failed to get irq resource\n");
>
> > + return -ENXIO;
>
> Why shadow actual error?
Sorry for missing this and will fix in next version.
>
> > + }
>
>
> > + if (!of_property_read_u32(dev->of_node, "clock-frequency", &prop))
> > + i2c_dev->bus_freq = prop;
> > +
> > + sprd_i2c_clk_init(i2c_dev);
> > + platform_set_drvdata(pdev, i2c_dev);
> > +
> > + pm_runtime_set_autosuspend_delay(i2c_dev->dev, SPRD_I2C_PM_TIMEOUT);
> > + pm_runtime_use_autosuspend(i2c_dev->dev);
> > + pm_runtime_set_active(i2c_dev->dev);
> > + pm_runtime_enable(i2c_dev->dev);
> > +
> > + ret = pm_runtime_get_sync(i2c_dev->dev);
> > + if (ret < 0) {
> > + dev_err(&pdev->dev, "i2c%d pm runtime resume failed!\n",
> > + pdev->id);
>
> > + return ret;
>
> goto error;
Yes, will fix it.
>
> > + }
> > +
> > + ret = devm_request_threaded_irq(dev, i2c_dev->irq,
> > + sprd_i2c_isr, sprd_i2c_isr_thread,
> > + IRQF_NO_SUSPEND | IRQF_ONESHOT,
> > + pdev->name, i2c_dev);
> > + if (ret) {
> > + dev_err(&pdev->dev, "failed to request irq %d\n", i2c_dev->irq);
> > + goto error;
> > + }
> > +
> > + ret = i2c_add_numbered_adapter(&i2c_dev->adap);
> > + if (ret) {
> > + dev_err(&pdev->dev, "add adapter failed\n");
> > + goto error;
> > + }
> > +
> > + pm_runtime_mark_last_busy(i2c_dev->dev);
> > + pm_runtime_put_autosuspend(i2c_dev->dev);
> > + return 0;
> > +
> > +error:
> > + pm_runtime_put_noidle(i2c_dev->dev);
> > + pm_runtime_disable(i2c_dev->dev);
> > + return ret;
> > +}
> > +
> > +static int sprd_i2c_remove(struct platform_device *pdev)
> > +{
> > + struct sprd_i2c *i2c_dev = platform_get_drvdata(pdev);
> > + int ret;
> > +
>
> > + ret = pm_runtime_get_sync(i2c_dev->dev);
> > + if (ret < 0)
> > + return ret;
>
> Does it make any sense? Doesn't device core power on the device before
> calling ->remove() ?
Yes, you are right. We need power on device in probe() function.
>
> > +
> > + i2c_del_adapter(&i2c_dev->adap);
> > +
> > + if (!IS_ERR_OR_NULL(i2c_dev->clk))
>
> _OR_NULL looks suspicious.
Since our ->clk can be NULL as one optional connfig in case we test I2C
driver on FPGA platform which does not support clock operation.
>
> > + clk_unprepare(i2c_dev->clk);
> > +
> > + pm_runtime_put_noidle(i2c_dev->dev);
> > + pm_runtime_disable(i2c_dev->dev);
> > +
> > + return 0;
> > +}
> > +
>
> > +#ifdef CONFIG_PM_SLEEP
>
> __maybe_unused instead?
OK.
>
> > +static int sprd_i2c_suspend_noirq(struct device *pdev)
>
> > +static int sprd_i2c_resume_noirq(struct device *pdev)
>
> > +#endif /* CONFIG_PM_SLEEP */
>
> > +#ifdef CONFIG_PM
>
> Ditto.
OK.
>
> > +static int sprd_i2c_runtime_suspend(struct device *pdev)
>
> > +}
>
> > +static int sprd_i2c_runtime_resume(struct device *pdev)
> > +{
>
> > + clk_prepare_enable(i2c_dev->clk);
>
> This might fail.
Yes, will check return value.
>
>
> > +}
> > +#endif /* CONFIG_PM */
>
>
> > +static struct platform_driver sprd_i2c_driver = {
> > + .probe = sprd_i2c_probe,
> > + .remove = sprd_i2c_remove,
> > + .driver = {
> > + .name = "sprd-i2c",
>
> > + .of_match_table = of_match_ptr(sprd_i2c_of_match),
>
> of_match_ptr seems redundant.
OK.
>
> > + .pm = &sprd_i2c_pm_ops,
> > + },
> > +};
> > +
>
> > +static int __init sprd_i2c_init(void)
> > +{
> > + return platform_driver_register(&sprd_i2c_driver);
> > +}
>
> > +arch_initcall_sync(sprd_i2c_init);
>
> Why?
IN our Spreadtrum platform, our regulator driver will depend on I2C driver
and the regulator driver uses subsys_initcall() level to initialize. Moreover
some other drivers like GPU, they will depend on regulator to set voltage and
they also need initialization much earlier. Thanks for your comments.
>
> --
> With Best Regards,
> Andy Shevchenko
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