Wie Geräte in Gerätebaum- und Plattformtreibern verbunden wurden

Question

Ich habe Artikel zu diesem Thema gelesen. aber keiner von ihnen beschreibt die Details.

Was ich weiß, ist:

gpio0: gpio@44e07000 { 
    compatible = "ti,omap4-gpio"; 
    ... 
}; 

und stellen Sie die Verbindung zu Plattform-Treiber von

static const struct of_device_id omap_gpio_match[] = { 
    { 
     .compatible = "ti,omap4-gpio", 
    }, 
    { }, 
}; 
... 
static struct platform_driver omap_gpio_driver = { 
    .probe  = omap_gpio_probe, 
    .driver  = { 
     .name = "omap_gpio", 
     .pm = &gpio_pm_ops, 
     .of_match_table = of_match_ptr(omap_gpio_match), 
    }, 
}; 

und als Ergebnis:

"kompatibel" Eigenschaft im Geräte-Baum erklären , of_match_table wird verwendet, um die compat anzupassen iible Eigenschaft in Device Tree deklariert.

und die Übereinstimmungs-Aktion in platform_match (drivers/base/platform.c) Funktion durchgeführt. Ich bezweifle dies, weil die I Greped-Referenz von of_match_table und das einzige wahrscheinliche Ergebnis in of_device_get_match_data (drivers/of/device.c) Funktion befindet.

~/wk/linux$ find . -name '*.c' | xargs grep '\<of_match_table\>' | grep -v -E 'of_match_table\s+=' 
./drivers/dma/sirf-dma.c:    (of_match_device(op->dev.driver->of_match_table, 
./drivers/macintosh/macio_asic.c:  const struct of_device_id * matches = drv->of_match_table; 
./drivers/macintosh/macio_asic.c:  match = of_match_device(drv->driver.of_match_table, dev); 
./drivers/nvmem/mxs-ocotp.c: match = of_match_device(dev->driver->of_match_table, dev); 
./drivers/reset/sti/reset-syscfg.c:  match = of_match_device(dev->driver->of_match_table, dev); 
./drivers/mtd/devices/m25p80.c: * matching for .of_match_table 
./drivers/soc/rockchip/pm_domains.c: match = of_match_device(dev->driver->of_match_table, dev); 
./drivers/phy/phy-rockchip-usb.c:  match = of_match_device(dev->driver->of_match_table, dev); 
./drivers/acpi/bus.c: * @of_match_table: List of device IDs to match against. 
./drivers/acpi/bus.c:       const struct of_device_id *of_match_table) 
./drivers/acpi/bus.c: if (!of_match_table || !of_compatible) 
./drivers/acpi/bus.c:   for (id = of_match_table; id->compatible[0]; id++) 
./drivers/acpi/bus.c:          drv->of_match_table); 
./drivers/acpi/bus.c:        drv->acpi_match_table, drv->of_match_table); 
./drivers/pci/host/pcie-hisi.c: match = of_match_device(driver->of_match_table, &pdev->dev); 
./drivers/pinctrl/stm32/pinctrl-stm32.c:  match = of_match_device(dev->driver->of_match_table, dev); 
./drivers/of/device.c: match = of_match_device(dev->driver->of_match_table, dev); 
./drivers/mfd/axp20x.c:   of_id = of_match_device(dev->driver->of_match_table, dev); 
./drivers/gpu/drm/armada/armada_crtc.c:   match = of_match_device(dev->driver->of_match_table, dev); 
./arch/powerpc/kernel/ibmebus.c:  ibmebus_create_devices(drv->driver.of_match_table); 
./arch/powerpc/kernel/ibmebus.c:  const struct of_device_id *matches = drv->of_match_table; 
./sound/soc/qcom/lpass-cpu.c: match = of_match_device(dev->driver->of_match_table, dev); 

Diese Funktion wird jedoch in einigen gebräuchlichen Modulen nicht verwendet.

~/wk/linux$ find . -name '*.c' | xargs grep of_device_get_match_data 
./drivers/dma/sh/shdmac.c:    pdata = of_device_get_match_data(&pdev->dev); 
./drivers/dma/tegra210-adma.c: cdata = of_device_get_match_data(&pdev->dev); 
./drivers/dma/tegra20-apb-dma.c:  cdata = of_device_get_match_data(&pdev->dev); 
./drivers/usb/host/xhci-tegra.c:  tegra->soc = of_device_get_match_data(&pdev->dev); 
./drivers/usb/phy/phy-msm-usb.c:  pdata->phy_type = (enum msm_usb_phy_type)of_device_get_match_data(&pdev->dev); 
./drivers/mtd/spi-nor/fsl-quadspi.c: q->devtype_data = of_device_get_match_data(dev); 
./drivers/mtd/nand/qcom_nandc.c:  dev_data = of_device_get_match_data(dev); 
./drivers/mtd/nand/atmel_nand.c:    of_device_get_match_data(host->dev); 
./drivers/rtc/rtc-sunxi.c:  chip->data_year = of_device_get_match_data(&pdev->dev); 
./drivers/spi/spi-mpc512x-psc.c:  mps->type = (int)of_device_get_match_data(dev); 
./drivers/watchdog/mpc8xxx_wdt.c:  wdt_type = of_device_get_match_data(&ofdev->dev); 
./drivers/phy/phy-exynos-mipi-video.c: phy_dev = of_device_get_match_data(dev); 
./drivers/phy/phy-sun4i-usb.c: data->cfg = of_device_get_match_data(dev); 
./drivers/pci/host/pci-imx6.c:   (enum imx6_pcie_variants)of_device_get_match_data(&pdev->dev); 
./drivers/pci/host/pcie-qcom.c: pcie->ops = (struct qcom_pcie_ops *)of_device_get_match_data(dev); 
./drivers/i2c/busses/i2c-rcar.c:  priv->devtype = (enum rcar_i2c_type)of_device_get_match_data(dev); 
./drivers/i2c/busses/i2c-tegra.c:    i2c_dev->hw = of_device_get_match_data(&pdev->dev); 
./drivers/tty/serial/imx.c:  sport->devdata = of_device_get_match_data(&pdev->dev); 
./drivers/gpio/gpio-mpc8xxx.c:   of_device_get_match_data(&pdev->dev); 
./drivers/gpio/gpio-tegra.c: config = of_device_get_match_data(&pdev->dev); 
./drivers/clk/clk-palmas.c:  match_data = of_device_get_match_data(&pdev->dev); 
./drivers/input/misc/pmic8xxx-pwrkey.c: pwrkey->shutdown_fn = of_device_get_match_data(&pdev->dev); 
./drivers/input/touchscreen/edt-ft5x06.c:  chip_data = of_device_get_match_data(&client->dev); 
./drivers/pinctrl/sh-pfc/core.c:    info = of_device_get_match_data(&pdev->dev); 
./drivers/thermal/rcar_thermal.c:  unsigned long of_data = (unsigned long)of_device_get_match_data(dev); 
./drivers/net/ethernet/stmicro/stmmac/dwmac-sti.c:  data = of_device_get_match_data(&pdev->dev); 
./drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c:  data = of_device_get_match_data(&pdev->dev); 
./drivers/net/ethernet/renesas/sh_eth.c:    mdp->cd = (struct sh_eth_cpu_data *)of_device_get_match_data(&pdev->dev); 
./drivers/net/ethernet/renesas/ravb_main.c:  chip_id = (enum ravb_chip_id)of_device_get_match_data(&pdev->dev); 
./drivers/of/device.c:const void *of_device_get_match_data(const struct device *dev) 
./drivers/of/device.c:EXPORT_SYMBOL(of_device_get_match_data); 
./drivers/gpu/drm/nouveau/nouveau_platform.c: func = of_device_get_match_data(&pdev->dev); 
./drivers/gpu/drm/exynos/exynos_drm_rotator.c:       of_device_get_match_data(dev); 
./drivers/gpu/drm/exynos/exynos_mixer.c:  drv = of_device_get_match_data(dev); 
./drivers/gpu/drm/exynos/exynos5433_drm_decon.c:  ctx->out_type = (unsigned long)of_device_get_match_data(dev); 
./drivers/gpu/drm/exynos/exynos_drm_fimd.c:  ctx->driver_data = of_device_get_match_data(dev); 
./drivers/gpu/drm/exynos/exynos_hdmi.c: hdata->drv_data = of_device_get_match_data(dev); 
./drivers/gpu/drm/exynos/exynos_drm_dsi.c:  dsi->driver_data = of_device_get_match_data(dev); 
./drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.c:  dc_ops = (struct kirin_dc_ops *)of_device_get_match_data(dev); 
./drivers/gpu/drm/msm/hdmi/hdmi_phy.c: phy->cfg = (struct hdmi_phy_cfg *)of_device_get_match_data(dev); 
./drivers/gpu/drm/msm/hdmi/hdmi.c:      of_device_get_match_data(dev); 
./drivers/gpu/drm/msm/msm_drv.c:  return (int) (unsigned long) of_device_get_match_data(dev); 
./drivers/gpu/drm/rockchip/rockchip_drm_vop.c: vop_data = of_device_get_match_data(dev); 
./sound/soc/sh/rcar/core.c:  priv->flags  = (unsigned long)of_device_get_match_data(dev); 
./sound/soc/sh/rcar/rsrc-card.c:    of_data = of_device_get_match_data(dev); 
./sound/soc/sh/rcar/rsrc-card.c:  const struct rsrc_card_of_data *of_data = of_device_get_match_data(dev); 

Jeder kann einige nützliche Informationen geben?

probe(struct bus_client *client, 
      const struct bus_device_id *id) 
{ 

    const struct of_device_id *match; 

    match = of_match_device(omap_gpio_match); 
    if (!match) 
      return -ENODEV; 
    else 
     //write the driver stuff for Probe 

Dies ist, wie die Gerätebaum mit Ihrem Fahrer verbunden:

Answer 1

in der Sonde Funktion des Fahrers dort sein muss/müssen diese Zeile sein. omap_gpio_match Sie haben bereits eine Verbindung mit der "kompatiblen ID" hergestellt, die Sie in der Gerätestruktur definiert haben, und so wurde der Treiber mit der Gerätestruktur verknüpft.

Answer 2

Die kanonische Antwort auf Ihre Frage finden Sie unter LWN: Platform Devices and Device Trees. Was Sie brauchen, ist die richtige Anleitung zur Verwendung. A Tutorial on the Device Tree ist eine vernünftige Anleitung. Für den Hintergrund sollten Sie über Linux and the Device Tree lesen. Außerdem hat elinux.org ein paar Wikis, die helfen sollten, wie Device Tree Linux und Device Tree Usage und Device Tree Reference.