[PATCH v2 3/6] irqchip: irq-mvebu-gicp: new driver for Marvell GICP
Marc Zyngier
marc.zyngier at arm.com
Thu Jun 8 08:07:40 PDT 2017
Hi Thomas,
On 02/06/17 11:06, Thomas Petazzoni wrote:
> This commit adds a simple driver for the Marvell GICP, a hardware unit
> that converts memory writes into GIC SPI interrupts. The driver provides
> a number of functions to the ICU driver to allocate GICP interrupts, and
> get the physical addresses that the ICUs should write to to set/clear
> interrupts.
>
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
> ---
> drivers/irqchip/Kconfig | 3 +
> drivers/irqchip/Makefile | 1 +
> drivers/irqchip/irq-mvebu-gicp.c | 170 +++++++++++++++++++++++++++++++++++++++
> drivers/irqchip/irq-mvebu-gicp.h | 15 ++++
> 4 files changed, 189 insertions(+)
> create mode 100644 drivers/irqchip/irq-mvebu-gicp.c
> create mode 100644 drivers/irqchip/irq-mvebu-gicp.h
>
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index 478f8ac..e527ee5 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -268,6 +268,9 @@ config IRQ_MXS
> select IRQ_DOMAIN
> select STMP_DEVICE
>
> +config MVEBU_GICP
> + bool
> +
> config MVEBU_ODMI
> bool
> select GENERIC_MSI_IRQ_DOMAIN
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index b64c59b..11eb858 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -69,6 +69,7 @@ obj-$(CONFIG_ARCH_SA1100) += irq-sa11x0.o
> obj-$(CONFIG_INGENIC_IRQ) += irq-ingenic.o
> obj-$(CONFIG_IMX_GPCV2) += irq-imx-gpcv2.o
> obj-$(CONFIG_PIC32_EVIC) += irq-pic32-evic.o
> +obj-$(CONFIG_MVEBU_GICP) += irq-mvebu-gicp.o
> obj-$(CONFIG_MVEBU_ODMI) += irq-mvebu-odmi.o
> obj-$(CONFIG_MVEBU_PIC) += irq-mvebu-pic.o
> obj-$(CONFIG_LS_SCFG_MSI) += irq-ls-scfg-msi.o
> diff --git a/drivers/irqchip/irq-mvebu-gicp.c b/drivers/irqchip/irq-mvebu-gicp.c
> new file mode 100644
> index 0000000..73c0117
> --- /dev/null
> +++ b/drivers/irqchip/irq-mvebu-gicp.c
> @@ -0,0 +1,170 @@
> +/*
> + * Copyright (C) 2017 Marvell
> + *
> + * Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +
> +#include "irq-mvebu-gicp.h"
> +
> +#define GICP_SETSPI_NSR_OFFSET 0x0
> +#define GICP_CLRSPI_NSR_OFFSET 0x8
> +
> +struct mvebu_gicp_spi_range {
> + unsigned int start;
> + unsigned int count;
> +};
> +
> +struct mvebu_gicp {
> + struct mvebu_gicp_spi_range *spi_ranges;
> + unsigned int spi_ranges_cnt;
> + unsigned int spi_cnt;
> + unsigned long *spi_bitmap;
> + spinlock_t spi_lock;
> + struct resource *res;
> +};
> +
> +int mvebu_gicp_alloc(struct mvebu_gicp *gicp)
> +{
> + int idx;
> +
> + spin_lock(&gicp->spi_lock);
> + idx = find_first_zero_bit(gicp->spi_bitmap, gicp->spi_cnt);
> + if (idx == gicp->spi_cnt) {
> + spin_unlock(&gicp->spi_lock);
> + return -ENOSPC;
> + }
> + set_bit(idx, gicp->spi_bitmap);
> + spin_unlock(&gicp->spi_lock);
> +
> + return idx;
> +}
> +
> +void mvebu_gicp_free(struct mvebu_gicp *gicp, int idx)
> +{
> + spin_lock(&gicp->spi_lock);
> + clear_bit(idx, gicp->spi_bitmap);
> + spin_unlock(&gicp->spi_lock);
> +}
> +
> +int mvebu_gicp_idx_to_spi(struct mvebu_gicp *gicp, int idx)
> +{
> + int i;
> +
> + for (i = 0; i < gicp->spi_ranges_cnt; i++) {
> + struct mvebu_gicp_spi_range *r = &gicp->spi_ranges[i];
> +
> + if (idx < r->count)
> + return r->start + idx;
> +
> + idx -= r->count;
> + }
> +
> + return -EINVAL;
> +}
> +
> +int mvebu_gicp_spi_to_idx(struct mvebu_gicp *gicp, int spi)
> +{
> + int i;
> + int idx = 0;
> +
> + for (i = 0; i < gicp->spi_ranges_cnt; i++) {
> + struct mvebu_gicp_spi_range *r = &gicp->spi_ranges[i];
> +
> + if (spi >= r->start && spi < (r->start + r->count))
> + return idx + (spi - r->start);
> +
> + idx += r->count;
> + }
> +
> + return -EINVAL;
> +}
> +
> +int mvebu_gicp_spi_count(struct mvebu_gicp *gicp)
> +{
> + return gicp->spi_cnt;
> +}
> +
> +phys_addr_t mvebu_gicp_setspi_phys_addr(struct mvebu_gicp *gicp)
> +{
> + return gicp->res->start + GICP_SETSPI_NSR_OFFSET;
> +}
> +
> +phys_addr_t mvebu_gicp_clrspi_phys_addr(struct mvebu_gicp *gicp)
> +{
> + return gicp->res->start + GICP_CLRSPI_NSR_OFFSET;
> +}
> +
> +static int mvebu_gicp_probe(struct platform_device *pdev)
> +{
> + struct mvebu_gicp *gicp;
> + int ret, i;
> +
> + gicp = devm_kzalloc(&pdev->dev, sizeof(*gicp), GFP_KERNEL);
> + if (!gicp)
> + return -ENOMEM;
> +
> + gicp->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!gicp->res)
> + return -ENODEV;
> +
> + ret = of_property_count_u32_elems(pdev->dev.of_node,
> + "marvell,spi-ranges");
> + if (ret < 0)
> + return ret;
> +
> + gicp->spi_ranges_cnt = ret / 2;
> +
> + gicp->spi_ranges =
> + devm_kzalloc(&pdev->dev,
> + gicp->spi_ranges_cnt *
> + sizeof(struct mvebu_gicp_spi_range),
> + GFP_KERNEL);
> + if (!gicp->spi_ranges)
> + return -ENOMEM;
> +
> + for (i = 0; i < gicp->spi_ranges_cnt; i++) {
> + of_property_read_u32_index(pdev->dev.of_node,
> + "marvell,spi-ranges",
> + i * 2,
> + &gicp->spi_ranges[i].start);
> +
> + of_property_read_u32_index(pdev->dev.of_node,
> + "marvell,spi-ranges",
> + i * 2 + 1,
> + &gicp->spi_ranges[i].count);
> +
> + gicp->spi_cnt += gicp->spi_ranges[i].count;
> + }
> +
> + gicp->spi_bitmap = devm_kzalloc(&pdev->dev,
> + BITS_TO_LONGS(gicp->spi_cnt),
> + GFP_KERNEL);
> + if (!gicp->spi_bitmap)
> + return -ENOMEM;
> +
> + platform_set_drvdata(pdev, gicp);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id mvebu_gicp_of_match[] = {
> + { .compatible = "marvell,ap806-gicp", },
> + {},
> +};
> +
> +static struct platform_driver mvebu_gicp_driver = {
> + .probe = mvebu_gicp_probe,
> + .driver = {
> + .name = "mvebu-gicp",
> + .of_match_table = mvebu_gicp_of_match,
> + },
> +};
> +builtin_platform_driver(mvebu_gicp_driver);
> diff --git a/drivers/irqchip/irq-mvebu-gicp.h b/drivers/irqchip/irq-mvebu-gicp.h
> new file mode 100644
> index 0000000..7290166
> --- /dev/null
> +++ b/drivers/irqchip/irq-mvebu-gicp.h
> @@ -0,0 +1,15 @@
> +#ifndef __MVEBU_GICP_H__
> +#define __MVEBU_GICP_H__
> +
> +struct mvebu_gicp;
> +
> +int mvebu_gicp_alloc(struct mvebu_gicp *gicp);
> +void mvebu_gicp_free(struct mvebu_gicp *gicp, int idx);
> +int mvebu_gicp_idx_to_spi(struct mvebu_gicp *gicp, int idx);
> +int mvebu_gicp_spi_to_idx(struct mvebu_gicp *gicp, int spi);
> +phys_addr_t mvebu_gicp_setspi_phys_addr(struct mvebu_gicp *gicp);
> +phys_addr_t mvebu_gicp_clrspi_phys_addr(struct mvebu_gicp *gicp);
> +int mvebu_gicp_spi_count(struct mvebu_gicp *gicp);
> +
> +#endif /* __MVEBU_GICP_H__ */
> +
>
The more I look at this code, the more I think this should actually be
an IRQ domain of its own. It already has an allocator, and I believe a
number of these exported functions disappear by virtue of having linked
data structures.
Also, given that this GICP is a perfect clone of the equivalent GICv3
feature, we could use it the same way should someone glue an ICU on a
GICv3 system...
I appreciate that I did say the exact opposite on IRC, but hey, I admit
I was wrong! ;-)
What do you think?
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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