Messages in this thread | | | Date | Mon, 11 Jan 2016 17:13:20 +0200 | Subject | Re: [PATCH v5 2/2] ACPI: amba bus probing support | From | Andy Shevchenko <> |
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On Mon, Jan 11, 2016 at 3:26 PM, Aleksey Makarov <aleksey.makarov@linaro.org> wrote: > From: Graeme Gregory <graeme.gregory@linaro.org> > > On ARM64 some devices use the AMBA device and not the platform bus for > probing so add support for this. Uses a dummy clock for apb_pclk as ACPI > does not have a suitable clock representation and to keep the core > AMBA bus code unchanged between probing methods. >
My comments below.
> +++ b/drivers/acpi/acpi_amba.c > @@ -0,0 +1,122 @@ > + > +/* > + * ACPI support for platform bus type. > + * > + * Copyright (C) 2015, Linaro Ltd > + * Author: Graeme Gregory <graeme.gregory@linaro.org> > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + */ > + > +#include <linux/acpi.h> > +#include <linux/amba/bus.h> > +#include <linux/clkdev.h> > +#include <linux/clk-provider.h> > +#include <linux/device.h> > +#include <linux/err.h> > +#include <linux/ioport.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > + > +#include "internal.h" > + > +static const struct acpi_device_id amba_id_list[] = { > + {"ARMH0061", 0}, /* PL061 GPIO Device */ > + {"", 0}, > +}; > + > +static void amba_register_dummy_clk(void) > +{ > + static struct clk *amba_dummy_clk; > + > + /* If clock already registered */ > + if (amba_dummy_clk) > + return; > + > + amba_dummy_clk = clk_register_fixed_rate(NULL, "apb_pclk", NULL, > + CLK_IS_ROOT, 0); > + clk_register_clkdev(amba_dummy_clk, "apb_pclk", NULL); > +} > + > +static int amba_handler_attach(struct acpi_device *adev, > + const struct acpi_device_id *id) > +{ > + struct amba_device *dev; > + struct resource_entry *rentry; > + struct list_head resource_list; > + bool address_found = false; > + int irq_no = 0; > + int ret; > + > + /* If the ACPI node already has a physical device attached, skip it. */ > + if (adev->physical_node_count) > + return 0; > + > + dev = amba_device_alloc(dev_name(&adev->dev), 0, 0); > + if (!dev) { > + dev_err(&adev->dev, "%s(): amba_device_alloc() failed\n", > + __func__); > + return -ENOMEM; > + } > + > + INIT_LIST_HEAD(&resource_list); > + ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL); > + if (ret < 0) > + goto err_free; > + > + list_for_each_entry(rentry, &resource_list, node) { > + switch (resource_type(rentry->res)) { > + case IORESOURCE_MEM: > + if (!address_found) { > + dev->res = *rentry->res;
dev->res is 0 before this one, right? Could you use this fact instead of address_found flag?
> + address_found = true; > + } > + break; > + case IORESOURCE_IRQ: > + if (irq_no < AMBA_NR_IRQS) > + dev->irq[irq_no++] = rentry->res->start; > + break; > + default: > + dev_warn(&adev->dev, "Invalid resource\n");
Why? Isn't possible to have other resources for the devices?
> + break; > + } > + } > + > + acpi_dev_free_resource_list(&resource_list); > + > + /* > + * If the ACPI node has a parent and that parent has a physical device > + * attached to it, that physical device should be the parent of > + * the amba device we are about to create. > + */ > + if (adev->parent) > + dev->dev.parent = acpi_get_first_physical_node(adev->parent); > + > + ACPI_COMPANION_SET(&dev->dev, adev); > + > + ret = amba_device_add(dev, &iomem_resource); > + if (ret) {
ret < 0?
What to do if ret > 0? It will be considered as not error. Please, check what function returns and adjust this.
> + dev_err(&adev->dev, "%s(): amba_device_add() failed (%d)\n", > + __func__, ret); > + goto err_free; > + } > + > + return 1; > + > +err_free: > + amba_device_put(dev); > + return ret; > +}
-- With Best Regards, Andy Shevchenko
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