Re: [PATCH v1] i2c: eg20t: use generic power management

Wolfram Sang
2020-08-05T09:19:02Z

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On Mon, Jul 20, 2020 at 07:30:32PM +0530, Vaibhav Gupta wrote:
> Drivers using legacy PM have to manage PCI states and device's PM states
> themselves. They also need to take care of configuration registers.
>
> With improved and powerful support of generic PM, PCI Core takes care of
> above mentioned, device-independent, jobs.
>
> This driver makes use of PCI helper functions like
> pci_save/restore_state(), pci_enable/disable_device(),
> pci_enable_wake() and pci_set_power_state() to do required operations. In
> generic mode, they are no longer needed.
>
> Change function parameter in both .suspend() and .resume() to
> "struct device*" type. Use to_pci_dev() and dev_get_drvdata() to get
> "struct pci_dev*" variable and drv data.
>
> Compile-tested only.
>
> Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>

Looks reasonable, but to make sure I'd like a test from someone with HW
or an ack from someone more experienced with PCI details.

> ---
> drivers/i2c/busses/i2c-eg20t.c | 39 ++++++++--------------------------
> 1 file changed, 9 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-eg20t.c b/drivers/i2c/busses/i2c-eg20t.c
> index 73f139690e4e..c0ddc4cc2ce7 100644
> --- a/drivers/i2c/busses/i2c-eg20t.c
> +++ b/drivers/i2c/busses/i2c-eg20t.c
> @@ -846,11 +846,10 @@ static void pch_i2c_remove(struct pci_dev *pdev)
> kfree(adap_info);
> }
>
> -#ifdef CONFIG_PM
> -static int pch_i2c_suspend(struct pci_dev *pdev, pm_message_t state)
> +static int __maybe_unused pch_i2c_suspend(struct device *dev)
> {
> - int ret;
> int i;
> + struct pci_dev *pdev = to_pci_dev(dev);
> struct adapter_info *adap_info = pci_get_drvdata(pdev);
> void __iomem *p = adap_info->pch_data[0].pch_base_address;
>
> @@ -872,34 +871,17 @@ static int pch_i2c_suspend(struct pci_dev *pdev, pm_message_t state)
> ioread32(p + PCH_I2CSR), ioread32(p + PCH_I2CBUFSTA),
> ioread32(p + PCH_I2CESRSTA));
>
> - ret = pci_save_state(pdev);
> -
> - if (ret) {
> - pch_pci_err(pdev, "pci_save_state\n");
> - return ret;
> - }
> -
> - pci_enable_wake(pdev, PCI_D3hot, 0);
> - pci_disable_device(pdev);
> - pci_set_power_state(pdev, pci_choose_state(pdev, state));
> + device_wakeup_disable(dev);
>
> return 0;
> }
>
> -static int pch_i2c_resume(struct pci_dev *pdev)
> +static int __maybe_unused pch_i2c_resume(struct device *dev)
> {
> int i;
> - struct adapter_info *adap_info = pci_get_drvdata(pdev);
> -
> - pci_set_power_state(pdev, PCI_D0);
> - pci_restore_state(pdev);
> + struct adapter_info *adap_info = dev_get_drvdata(dev);
>
> - if (pci_enable_device(pdev) < 0) {
> - pch_pci_err(pdev, "pch_i2c_resume:pci_enable_device FAILED\n");
> - return -EIO;
> - }
> -
> - pci_enable_wake(pdev, PCI_D3hot, 0);
> + device_wakeup_disable(dev);
>
> for (i = 0; i < adap_info->ch_num; i++)
> pch_i2c_init(&adap_info->pch_data[i]);
> @@ -908,18 +890,15 @@ static int pch_i2c_resume(struct pci_dev *pdev)
>
> return 0;
> }
> -#else
> -#define pch_i2c_suspend NULL
> -#define pch_i2c_resume NULL
> -#endif
> +
> +static SIMPLE_DEV_PM_OPS(pch_i2c_pm_ops, pch_i2c_suspend, pch_i2c_resume);
>
> static struct pci_driver pch_pcidriver = {
> .name = KBUILD_MODNAME,
> .id_table = pch_pcidev_id,
> .probe = pch_i2c_probe,
> .remove = pch_i2c_remove,
> - .suspend = pch_i2c_suspend,
> - .resume = pch_i2c_resume
> + .driver.pm = &pch_i2c_pm_ops,
> };
>
> module_pci_driver(pch_pcidriver);

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