Hi Jon,
On 07/06/16 16:12, Jon Hunter wrote:
> Add a platform driver to support non-root GICs that require runtime
> power-management. Currently, only non-root GICs are supported because
> the functions, smp_cross_call() and set_handle_irq(), that need to
> be called for a root controller are located in the __init section and
> so cannot be called by the platform driver.
>
> The GIC platform driver re-uses many functions from the existing GIC
> driver including some functions to save and restore the GIC context
> during power transitions. The functions for saving and restoring the
> GIC context are currently only defined if CONFIG_CPU_PM is enabled and
> to ensure that these functions are always defined when the platform
> driver is enabled, a dependency on CONFIG_ARM_GIC_PM (which selects the
> platform driver) has been added.
>
> In order to re-use the private GIC initialisation code, a new public
> function, gic_of_init_child(), has been added which calls various
> private functions to initialise the GIC. This is different from the
> existing gic_of_init() because it only supports non-root GICs (ie. does
> not call smp_cross_call() is set_handle_irq()) and is not located in
> the __init section (so can be used by platform drivers). Furthermore,
> gic_of_init_child() dynamically allocates memory for the GIC chip data
> which is also different from gic_of_init().
>
> There is no specific suspend handling for GICs registered as platform
> devices. Non-wakeup interrupts will be disabled by the kernel during
> late suspend, however, this alone will not power down the GIC if
> interrupts have been requested and not freed. Therefore, requestors of
> non-wakeup interrupts will need to free them on entering suspend in
> order to power-down the GIC.
>
> Signed-off-by: Jon Hunter <[email protected]>
> ---
> drivers/irqchip/Kconfig | 6 ++
> drivers/irqchip/Makefile | 1 +
> drivers/irqchip/irq-gic-pm.c | 184
> ++++++++++++++++++++++++++++++++++++++++
> drivers/irqchip/irq-gic.c | 38 ++++++++-
> include/linux/irqchip/arm-gic.h | 6 ++
> 5 files changed, 232 insertions(+), 3 deletions(-)
> create mode 100644 drivers/irqchip/irq-gic-pm.c
>
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index fa33c50b0e5a..5495a5ba8039 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -8,6 +8,12 @@ config ARM_GIC
> select IRQ_DOMAIN_HIERARCHY
> select MULTI_IRQ_HANDLER
>
> +config ARM_GIC_PM
> + bool
> + depends on PM
> + select ARM_GIC
> + select PM_CLK
> +
> config ARM_GIC_MAX_NR
> int
> default 2 if ARCH_REALVIEW
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index 38853a187607..bd0257e0aab6 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -24,6 +24,7 @@ obj-$(CONFIG_ARCH_SUNXI) += irq-sun4i.o
> obj-$(CONFIG_ARCH_SUNXI) += irq-sunxi-nmi.o
> obj-$(CONFIG_ARCH_SPEAR3XX) += spear-shirq.o
> obj-$(CONFIG_ARM_GIC) += irq-gic.o irq-gic-common.o
> +obj-$(CONFIG_ARM_GIC_PM) += irq-gic-pm.o
> obj-$(CONFIG_REALVIEW_DT) += irq-gic-realview.o
> obj-$(CONFIG_ARM_GIC_V2M) += irq-gic-v2m.o
> obj-$(CONFIG_ARM_GIC_V3) += irq-gic-v3.o irq-gic-common.o
> diff --git a/drivers/irqchip/irq-gic-pm.c b/drivers/irqchip/irq-gic-pm.c
> new file mode 100644
> index 000000000000..4cbffba3ff13
> --- /dev/null
> +++ b/drivers/irqchip/irq-gic-pm.c
> @@ -0,0 +1,184 @@
> +/*
> + * Copyright (C) 2016 NVIDIA CORPORATION, All Rights Reserved.
> + *
> + * 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.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +#include <linux/module.h>
> +#include <linux/clk.h>
> +#include <linux/of_device.h>
> +#include <linux/of_irq.h>
> +#include <linux/irqchip/arm-gic.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_clock.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/slab.h>
> +
> +struct gic_clk_data {
> + unsigned int num_clocks;
> + const char *const *clocks;
> +};
> +
> +static int gic_runtime_resume(struct device *dev)
> +{
> + struct gic_chip_data *gic = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = pm_clk_resume(dev);
> + if (ret)
> + return ret;
> +
> + /*
> + * On the very first resume, the pointer to the driver data
> + * will be NULL and this is intentional, because we do not
> + * want to restore the GIC on the very first resume. So if
> + * the pointer is not valid just return.
> + */
> + if (!gic)
> + return 0;
> +
> + gic_dist_restore(gic);
> + gic_cpu_restore(gic);
> +
> + return 0;
> +}
> +
> +static int gic_runtime_suspend(struct device *dev)
> +{
> + struct gic_chip_data *gic = dev_get_drvdata(dev);
> +
> + gic_dist_save(gic);
> + gic_cpu_save(gic);
> +
> + return pm_clk_suspend(dev);
> +}
> +
> +static int gic_get_clocks(struct device *dev, const struct gic_clk_data
> *data)
> +{
> + struct clk *clk;
> + unsigned int i;
> + int ret;
> +
> + if (!dev || !data)
> + return -EINVAL;
> +
> + ret = pm_clk_create(dev);
> + if (ret)
> + return ret;
> +
> + for (i = 0; i < data->num_clocks; i++) {
> + clk = of_clk_get_by_name(dev->of_node, data->clocks[i]);
> + if (IS_ERR(clk)) {
> + dev_err(dev, "failed to get clock %s\n",
> + data->clocks[i]);
> + ret = PTR_ERR(clk);
> + goto error;
> + }
> +
> + ret = pm_clk_add_clk(dev, clk);
> + if (ret) {
> + dev_err(dev, "failed to add clock at index %d\n", i);
> + clk_put(clk);
> + goto error;
> + }
> + }
> +
> + return 0;
> +
> +error:
> + pm_clk_destroy(dev);
> +
> + return ret;
> +}
> +
> +static int gic_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + const struct gic_clk_data *data;
> + struct gic_chip_data *gic;
> + int ret, irq;
> +
> + data = of_device_get_match_data(&pdev->dev);
> + if (!data) {
> + dev_err(&pdev->dev, "no device match found\n");
> + return -ENODEV;
> + }
> +
> + irq = irq_of_parse_and_map(dev->of_node, 0);
> + if (!irq) {
> + dev_err(dev, "no parent interrupt found!\n");
> + return -EINVAL;
> + }
> +
> + ret = gic_get_clocks(dev, data);
> + if (ret)
> + goto irq_dispose;
> +
> + pm_runtime_enable(dev);
> +
> + ret = pm_runtime_get_sync(dev);
> + if (ret < 0)
> + goto rpm_disable;
> +
> + ret = gic_of_init_child(dev, &gic, irq);
> + if (ret)
> + goto rpm_put;
> +
> + platform_set_drvdata(pdev, gic);
> +
> + pm_runtime_put(dev);
> +
> + dev_info(dev, "GIC IRQ controller registered\n");
> +
> + return 0;
> +
> +rpm_put:
> + pm_runtime_put_sync(dev);
> +rpm_disable:
> + pm_runtime_disable(dev);
> + pm_clk_destroy(dev);
> +irq_dispose:
> + irq_dispose_mapping(irq);
> +
> + return ret;
> +}
> +
> +static const struct dev_pm_ops gic_pm_ops = {
> + SET_RUNTIME_PM_OPS(gic_runtime_suspend,
> + gic_runtime_resume, NULL)
> +};
> +
> +static const char * const gic400_clocks[] = {
> + "clk",
> +};
> +
> +static const struct gic_clk_data gic400_data = {
> + .num_clocks = ARRAY_SIZE(gic400_clocks),
> + .clocks = gic400_clocks,
> +};
> +
> +static const struct of_device_id gic_match[] = {
> + { .compatible = "nvidia,tegra210-agic", .data = &gic400_data },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, gic_match);
> +
> +static struct platform_driver gic_driver = {
> + .probe = gic_probe,
> + .driver = {
> + .name = "gic",
> + .of_match_table = gic_match,
> + .pm = &gic_pm_ops,
> + }
> +};
> +
> +builtin_platform_driver(gic_driver);
> diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
> index 141ea5801784..57423f3b218b 100644
> --- a/drivers/irqchip/irq-gic.c
> +++ b/drivers/irqchip/irq-gic.c
> @@ -75,7 +75,7 @@ struct gic_chip_data {
> void __iomem *raw_dist_base;
> void __iomem *raw_cpu_base;
> u32 percpu_offset;
> -#ifdef CONFIG_CPU_PM
> +#if defined(CONFIG_CPU_PM) || defined(CONFIG_ARM_GIC_PM)
> u32 saved_spi_enable[DIV_ROUND_UP(1020, 32)];
> u32 saved_spi_active[DIV_ROUND_UP(1020, 32)];
> u32 saved_spi_conf[DIV_ROUND_UP(1020, 16)];
> @@ -528,7 +528,7 @@ int gic_cpu_if_down(unsigned int gic_nr)
> return 0;
> }
>
> -#ifdef CONFIG_CPU_PM
> +#if defined(CONFIG_CPU_PM) || defined(CONFIG_ARM_GIC_PM)
> /*
> * Saves the GIC distributor registers during suspend or idle. Must be
> called
> * with interrupts disabled but before powering down the GIC. After calling
> @@ -1296,6 +1296,34 @@ error:
> return -ENOMEM;
> }
>
> +int gic_of_init_child(struct device *dev, struct gic_chip_data **gic, int
> irq)
I got this:
WARNING: drivers/built-in.o(.text+0x2464): Section mismatch in reference from
the function gic_of_init_child() to the function .init.text:gic_of_setup()
The function gic_of_init_child() references
the function __init gic_of_setup().
This is often because gic_of_init_child lacks a __init
annotation or the annotation of gic_of_setup is wrong.
I've fixed it locally by making the function __init.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
