ARM64 linux-kernel c linux-device-driver

了解Linux RegMap＆＃x27; d devm_regmap_init_mmio

发布于 2025-01-23 08:02:24 字数 896 浏览 3 评论 0原文

我想知道，如何使用Devm_regmap_init_mmio（）将16个字节的regmap导出（跨越两个子区域）。例如，从Linux中的一个驱动程序中：

    regs = devm_platform_ioremap_resource_byname(pdev, "ehb");
    if (IS_ERR(regs)) {
        dev_err(apb->dev, "Couldn't map APB EHB registers\n");
        return PTR_ERR(regs);
    }

    apb->regs = devm_regmap_init_mmio(apb->dev, regs, &bt1_apb_regmap_cfg);
    if (IS_ERR(apb->regs)) {
        dev_err(apb->dev, "Couldn't create APB EHB regmap\n");
        return PTR_ERR(apb->regs);

'带有BT1_APB_REGMAP_CFG填充的填充，

     static const struct regmap_config bt1_apb_regmap_cfg = {
    .reg_bits = 32,
    .val_bits = 32,
    .reg_stride = 4,
    .max_register = APB_EHB_TIMEOUT,
    .fast_io = true
};

看起来整个寄存器范围是使用devm_regmap_init_mmio导出的整个寄存器范围，但是是否有一种方法可以将仅导出16个野蛮人跨越四个寄存器？

另外，这些字段是什么.max_register和.reg_stride在这里意味着？

原文

I would like to know, how devm_regmap_init_mmio() can be used to export a regmap for 16 bytes (span over two subregions). For instance, from one of the driver in Linux:

    regs = devm_platform_ioremap_resource_byname(pdev, "ehb");
    if (IS_ERR(regs)) {
        dev_err(apb->dev, "Couldn't map APB EHB registers\n");
        return PTR_ERR(regs);
    }

    apb->regs = devm_regmap_init_mmio(apb->dev, regs, &bt1_apb_regmap_cfg);
    if (IS_ERR(apb->regs)) {
        dev_err(apb->dev, "Couldn't create APB EHB regmap\n");
        return PTR_ERR(apb->regs);

' with bt1_apb_regmap_cfg filled as

     static const struct regmap_config bt1_apb_regmap_cfg = {
    .reg_bits = 32,
    .val_bits = 32,
    .reg_stride = 4,
    .max_register = APB_EHB_TIMEOUT,
    .fast_io = true
};

here looks like whole register range is exported using devm_regmap_init_mmio but is there a way to export only 16 byters span across four register ?

Also, what are these fields .max_register and .reg_stride means here ?

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