> -----Original Message-----
> From: Pali Rohár <p...@kernel.org>
> Sent: Wednesday, August 19, 2020 16:57
> To: Stefan Roese <s...@denx.de>; Kostya Porotchkin <kos...@marvell.com>
> Cc: u-boot@lists.denx.de
> Subject: [EXT] [PATCH 2/2] arm64: a37xx: pci: Assert PERST# signal when
> unloading driver
>
> External Email
>
> ----------------------------------------------------------------------
> This change ensures that PCIe card is put into reset state when U-Boot stops
> using it.
>
> DM_FLAG_OS_PREPARE ensures that U-Boot executes driver's remove
> callback prior booting Linux kernel.
>
> Linux kernel pci-aardvark driver needs to reset PCIe card via PERST# signal
> prior initializing it. If it does not issue reset then some PCIe cards
> (specially
> Compex WiFi cards) are not detected at all.
>
> Putting PCIe card into reset state prior booting Linux kernel would ensure
> that card would be properly reset at time when Linux kernel starts
> initializing
> pci-aardvark driver.
>
> Signed-off-by: Pali Rohár <p...@kernel.org>
Reviewed-by: Konstantin Porotchkin <kos...@marvell.com>
> ---
> drivers/pci/pci-aardvark.c | 27 +++++++++++++++++++++------
> 1 file changed, 21 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/pci/pci-aardvark.c b/drivers/pci/pci-aardvark.c index
> 5b3f23c184..8996be5309 100644
> --- a/drivers/pci/pci-aardvark.c
> +++ b/drivers/pci/pci-aardvark.c
> @@ -148,6 +148,9 @@ struct pcie_advk {
> void *base;
> int first_busno;
> struct udevice *dev;
> +#if CONFIG_IS_ENABLED(DM_GPIO)
> + struct gpio_desc reset_gpio;
> +#endif
> };
>
> static inline void advk_writel(struct pcie_advk *pcie, uint val, uint reg)
> @@ -
> 614,9 +617,7 @@ static int pcie_advk_probe(struct udevice *dev)
> struct pcie_advk *pcie = dev_get_priv(dev);
>
> #if CONFIG_IS_ENABLED(DM_GPIO)
> - struct gpio_desc reset_gpio;
> -
> - gpio_request_by_name(dev, "reset-gpios", 0, &reset_gpio,
> + gpio_request_by_name(dev, "reset-gpios", 0, &pcie->reset_gpio,
> GPIOD_IS_OUT);
> /*
> * Issue reset to add-in card through the dedicated GPIO.
> @@ -631,11 +632,11 @@ static int pcie_advk_probe(struct udevice *dev)
> * possible before PCIe PHY initialization. Moreover, the PCIe
> * clock should be gated as well.
> */
> - if (dm_gpio_is_valid(&reset_gpio)) {
> + if (dm_gpio_is_valid(&pcie->reset_gpio)) {
> dev_dbg(pcie->dev, "Toggle PCIE Reset GPIO ...\n");
> - dm_gpio_set_value(&reset_gpio, 1);
> + dm_gpio_set_value(&pcie->reset_gpio, 1);
> mdelay(200);
> - dm_gpio_set_value(&reset_gpio, 0);
> + dm_gpio_set_value(&pcie->reset_gpio, 0);
> }
> #else
> dev_dbg(pcie->dev, "PCIE Reset on GPIO support is missing\n"); @@
> -647,6 +648,18 @@ static int pcie_advk_probe(struct udevice *dev)
> return pcie_advk_setup_hw(pcie);
> }
>
> +static int pcie_advk_remove(struct udevice *dev) { #if
> +CONFIG_IS_ENABLED(DM_GPIO)
> + struct pcie_advk *pcie = dev_get_priv(dev);
> +
> + if (dm_gpio_is_valid(&pcie->reset_gpio))
> + dm_gpio_set_value(&pcie->reset_gpio, 1); #endif /*
> DM_GPIO */
> +
> + return 0;
> +}
> +
> /**
> * pcie_advk_ofdata_to_platdata() - Translate from DT to device state
> *
> @@ -687,5 +700,7 @@ U_BOOT_DRIVER(pcie_advk) = {
> .ops = &pcie_advk_ops,
> .ofdata_to_platdata = pcie_advk_ofdata_to_platdata,
> .probe = pcie_advk_probe,
> + .remove = pcie_advk_remove,
> + .flags = DM_FLAG_OS_PREPARE,
> .priv_auto_alloc_size = sizeof(struct pcie_advk),
> };
> --
> 2.20.1
