On 04/06/16 11:10, Marc Zyngier wrote:
> On Thu, 12 May 2016 16:19:32 +0100
> Jon Hunter <[email protected]> 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, of_gic_init(), has been added which calls various private
>> functions to initialise the GIC.
>>
>> 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 | 187
>> +++++++++++++++++++++++++++++++++++++++++++
>> drivers/irqchip/irq-gic.c | 34 +++++++-
>> drivers/irqchip/irq-gic.h | 2 +
>> 5 files changed, 227 insertions(+), 3 deletions(-)
>> create mode 100644 drivers/irqchip/irq-gic-pm.c
>>
>> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
>> index 81f88ada3a61..68f65c84fdfd 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 f828244b44c2..eab28e80cd8d 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..a14331007bcf
>> --- /dev/null
>> +++ b/drivers/irqchip/irq-gic-pm.c
>> @@ -0,0 +1,187 @@
>> +/*
>> + * 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/platform_device.h>
>> +#include <linux/pm_clock.h>
>> +#include <linux/pm_runtime.h>
>> +#include <linux/slab.h>
>> +
>> +#include "irq-gic.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 = of_gic_init(dev, &gic);
>> + if (ret)
>> + goto rpm_put;
>> +
>> + irq_set_chained_handler_and_data(irq, gic_handle_cascade_irq, gic);
>
> nit: Rather than exporting the gic_handle_cascade entry point, I'd
> rather you exported a helper from the GIC driver. Something like:
>
> void gic_setup_cascade(int irq, struct gic_data *gic);
>
> and do the handler registration there. Alternatively, you could also
> move the irq parsing and handler registration into of_gic_init, and
> have this single initialization entry point.
Ok, yes I will do the latter.
>> +
>> + 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 9f8ab124898b..e65090f7afa4 100644
>> --- a/drivers/irqchip/irq-gic.c
>> +++ b/drivers/irqchip/irq-gic.c
>> @@ -76,7 +76,7 @@ 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(ARM_GIC_PM)
>
> Shouldn't that be CONFIG_ARM_GIC_PM?
Oops yes, will fix.
>> 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)];
>> @@ -526,7 +526,7 @@ int gic_cpu_if_down(unsigned int gic_nr)
>> return 0;
>> }
>>
>> -#ifdef CONFIG_CPU_PM
>> +#if defined(CONFIG_CPU_PM) || defined(ARM_GIC_PM)
>
> Same here?
Indeed! Cheers.
>> /*
>> * Saves the GIC distributor registers during suspend or idle. Must be
>> called
>> * with interrupts disabled but before powering down the GIC. After calling
>> @@ -1297,6 +1297,30 @@ error:
>> return -ENOMEM;
>> }
>>
>> +int of_gic_init(struct device *dev, struct gic_chip_data **gic)
>> +{
>> + int ret;
>> +
>> + if (!dev || !dev->of_node || !gic)
>> + return -EINVAL;
>> +
>> + *gic = devm_kzalloc(dev, sizeof(**gic), GFP_KERNEL);
>> + if (!*gic)
>> + return -ENOMEM;
>> +
>> + gic_init_chip(*gic, dev, dev->of_node->name, false);
>> +
>> + ret = gic_of_setup(*gic, dev->of_node);
>> + if (ret)
>> + return ret;
>> +
>> + ret = gic_init_bases(*gic, -1, &dev->of_node->fwnode);
>> + if (ret)
>> + gic_teardown(*gic);
>> +
>> + return ret;
>> +}
>> +
>> int __init
>> gic_of_init(struct device_node *node, struct device_node *parent)
>> {
>> @@ -1351,7 +1375,11 @@ IRQCHIP_DECLARE(cortex_a7_gic, "arm,cortex-a7-gic",
>> gic_of_init);
>> IRQCHIP_DECLARE(msm_8660_qgic, "qcom,msm-8660-qgic", gic_of_init);
>> IRQCHIP_DECLARE(msm_qgic2, "qcom,msm-qgic2", gic_of_init);
>> IRQCHIP_DECLARE(pl390, "arm,pl390", gic_of_init);
>> -
>> +#else
>> +int of_gic_init(struct device *dev, struct gic_chip_data **gic)
>> +{
>> + return -ENOTSUPP;
>> +}
>> #endif
>>
>> #ifdef CONFIG_ACPI
>> diff --git a/drivers/irqchip/irq-gic.h b/drivers/irqchip/irq-gic.h
>> index 646e92614b2c..b03ec4bac795 100644
>> --- a/drivers/irqchip/irq-gic.h
>> +++ b/drivers/irqchip/irq-gic.h
>> @@ -25,4 +25,6 @@ void gic_dist_save(struct gic_chip_data *gic);
>> void gic_dist_restore(struct gic_chip_data *gic);
>> void gic_handle_cascade_irq(struct irq_desc *desc);
>>
>> +int of_gic_init(struct device *dev, struct gic_chip_data **gic);
>> +
>> #endif /* _IRQ_GIC_H */
>
> Otherwise, looks good.
Thanks!
Jon
--
nvpublic
