| Message ID | 1452518790-27053-3-git-send-email-aleksey.makarov@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Jan 11, 2016 at 07:26:27PM +0600, Aleksey Makarov 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. > > Signed-off-by: Graeme Gregory <graeme.gregory@linaro.org> > Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org> This looks fine to me, thanks. Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
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; > +}
On Mon, Jan 11, 2016 at 05:13:20PM +0200, Andy Shevchenko wrote: > 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? amba_device_alloc() zero-initialises everything. However, dev->res is a struct resource, and I'd prefer _this_ method that the OT is using to testing some random part of struct resource. > > + 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? AMBA primecell devices have one memory region, and a number of interrupts. Other resource types don't make sense. > > + 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. Non-zero is treated as an error by amba_device_add(). Doing otherwise here puts it at odds to the outcome of that function. This code is fine.
On Mon, Jan 11, 2016 at 5:27 PM, Russell King - ARM Linux <linux@arm.linux.org.uk> wrote: > On Mon, Jan 11, 2016 at 05:13:20PM +0200, Andy Shevchenko wrote: >> On Mon, Jan 11, 2016 at 3:26 PM, Aleksey Makarov >> <aleksey.makarov@linaro.org> wrote: >> > From: Graeme Gregory <graeme.gregory@linaro.org> >> > +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? > > amba_device_alloc() zero-initialises everything. However, dev->res is > a struct resource, and I'd prefer _this_ method that the OT is using > to testing some random part of struct resource. So, you mean resource->start = 0 is not enough reliable? >> > + default: >> > + dev_warn(&adev->dev, "Invalid resource\n"); >> >> Why? Isn't possible to have other resources for the devices? > > AMBA primecell devices have one memory region, and a number of > interrupts. Other resource types don't make sense. But isn't warning on the other side too noisy? >> > + 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. > > Non-zero is treated as an error by amba_device_add(). > Doing otherwise > here puts it at odds to the outcome of that function. This code is fine. Yes, and in this case ret > 0 should be converted to an appropriate error code, otherwise ACPI core will consider this as a normal execution, right?
On Mon, Jan 11, 2016 at 06:26:00PM +0200, Andy Shevchenko wrote: > On Mon, Jan 11, 2016 at 5:27 PM, Russell King - ARM Linux > <linux@arm.linux.org.uk> wrote: > > On Mon, Jan 11, 2016 at 05:13:20PM +0200, Andy Shevchenko wrote: > >> On Mon, Jan 11, 2016 at 3:26 PM, Aleksey Makarov > >> <aleksey.makarov@linaro.org> wrote: > >> dev->res is 0 before this one, right? Could you use this fact instead > >> of address_found flag? > > > > amba_device_alloc() zero-initialises everything. However, dev->res is > > a struct resource, and I'd prefer _this_ method that the OT is using > > to testing some random part of struct resource. > > So, you mean resource->start = 0 is not enough reliable? I'd rather not make assumptions about what in a resource is valid or not valid. > >> > + default: > >> > + dev_warn(&adev->dev, "Invalid resource\n"); > >> > >> Why? Isn't possible to have other resources for the devices? > > > > AMBA primecell devices have one memory region, and a number of > > interrupts. Other resource types don't make sense. > > But isn't warning on the other side too noisy? Why would it be "too noisy" ? Isn't it saying that the ACPI is in error to include more resource types that aren't part of specifying the AMBA primecell device? Maybe it should be dev_err(), because it's technically an error... Are you expecting people to create ACPI tables with a lot of rubbish resources attached to these devices? > Yes, and in this case ret > 0 should be converted to an appropriate > error code, otherwise ACPI core will consider this as a normal > execution, right? You are assuming that it does return a positive non-zero value in the first place.
On Mon, Jan 11, 2016 at 7:24 PM, Russell King - ARM Linux <linux@arm.linux.org.uk> wrote: > On Mon, Jan 11, 2016 at 06:26:00PM +0200, Andy Shevchenko wrote: >> On Mon, Jan 11, 2016 at 5:27 PM, Russell King - ARM Linux >> <linux@arm.linux.org.uk> wrote: >> > On Mon, Jan 11, 2016 at 05:13:20PM +0200, Andy Shevchenko wrote: >> >> On Mon, Jan 11, 2016 at 3:26 PM, Aleksey Makarov >> >> <aleksey.makarov@linaro.org> wrote: >> >> dev->res is 0 before this one, right? Could you use this fact instead >> >> of address_found flag? >> > >> > amba_device_alloc() zero-initialises everything. However, dev->res is >> > a struct resource, and I'd prefer _this_ method that the OT is using >> > to testing some random part of struct resource. >> >> So, you mean resource->start = 0 is not enough reliable? > > I'd rather not make assumptions about what in a resource is valid > or not valid. Fair enough. >> >> > + default: >> >> > + dev_warn(&adev->dev, "Invalid resource\n"); >> >> >> >> Why? Isn't possible to have other resources for the devices? >> > >> > AMBA primecell devices have one memory region, and a number of >> > interrupts. Other resource types don't make sense. >> >> But isn't warning on the other side too noisy? > > Why would it be "too noisy" ? Isn't it saying that the ACPI is in > error to include more resource types that aren't part of specifying > the AMBA primecell device? Maybe it should be dev_err(), because > it's technically an error... > > Are you expecting people to create ACPI tables with a lot of rubbish > resources attached to these devices? I'm expecting broken ACPI tables coming from some vendors which is often the case for some devices. I would rather leave it as a warning or move to less verbose level. >> Yes, and in this case ret > 0 should be converted to an appropriate >> error code, otherwise ACPI core will consider this as a normal >> execution, right? > > You are assuming that it does return a positive non-zero value in the > first place. Frankly, I didn't check what that function can return, but I'm sure that if it will return positive value at some point this will print a message and tell ACPI that everything okay when it's not. So, here I suppose to have explicit check for that, or at least (if you believe that above will never happen) to show that only negative numbers are possible as error values. However, I will not insist if Rafael is okay with the original code.
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index 675eaf3..3cf732f 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -43,6 +43,7 @@ acpi-y += pci_root.o pci_link.o pci_irq.o acpi-y += acpi_lpss.o acpi_apd.o acpi-y += acpi_platform.o acpi-y += acpi_pnp.o +acpi-$(CONFIG_ARM_AMBA) += acpi_amba.o acpi-y += int340x_thermal.o acpi-y += power.o acpi-y += event.o diff --git a/drivers/acpi/acpi_amba.c b/drivers/acpi/acpi_amba.c new file mode 100644 index 0000000..2a61b54 --- /dev/null +++ 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; + 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"); + 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) { + 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; +} + +static struct acpi_scan_handler amba_handler = { + .ids = amba_id_list, + .attach = amba_handler_attach, +}; + +void __init acpi_amba_init(void) +{ + amba_register_dummy_clk(); + acpi_scan_add_handler(&amba_handler); +} diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h index ee9312ba..6086f66 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -29,6 +29,11 @@ void acpi_processor_init(void); void acpi_platform_init(void); void acpi_pnp_init(void); void acpi_int340x_thermal_init(void); +#ifdef CONFIG_ARM_AMBA +void acpi_amba_init(void); +#else +static inline void acpi_amba_init(void) {} +#endif int acpi_sysfs_init(void); void acpi_container_init(void); void acpi_memory_hotplug_init(void); diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 78d5f02..20c8cba 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -1922,6 +1922,7 @@ int __init acpi_scan_init(void) acpi_memory_hotplug_init(); acpi_pnp_init(); acpi_int340x_thermal_init(); + acpi_amba_init(); acpi_scan_add_handler(&generic_device_handler);