[PATCH v2 3/6] irqchip: irq-mvebu-gicp: new driver for Marvell GICP

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

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@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@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__ */
+
-- 
2.7.4