Hierarchical Interrupt Controller - Initial Draft

First draft or a new driver for the Tegra Hierarchical Interrupt
Controller. Enables and configures basic Mselect errors and interrupts
and hooks an interrupt handler.

Change-Id: I11c1987ad4fc6431b5d7f6948388d39c02279542
Signed-off-by: Neil Gabriel <ngabriel@nvidia.com>
Reviewed-on: http://git-master/r/366669
Reviewed-by: Mitch Luban <mluban@nvidia.com>
Tested-by: Mitch Luban <mluban@nvidia.com>

3 files changed, 202 insertions, 0 deletions

diff --git a/drivers/platform/tegra/Makefile b/drivers/platform/tegra/Makefile
index 5f5888a2bbbd..ee9f7e05aafb 100644
--- a/drivers/platform/tegra/Makefile
+++ b/drivers/platform/tegra/Makefile
@@ -105,3 +105,5 @@ else # --- CONFIG_ARM64 --- #
 obj-y += dummy.o # generate a built-in.o
 
 endif
+
+obj-y					+= hier_ictlr/
diff --git a/drivers/platform/tegra/hier_ictlr/Makefile b/drivers/platform/tegra/hier_ictlr/Makefile
new file mode 100644
index 000000000000..bfcbe36455c6
--- /dev/null
+++ b/drivers/platform/tegra/hier_ictlr/Makefile
@@ -0,0 +1,8 @@
+#
+# Makefile for tegra ...
+#
+
+subdir-ccflags-y = -Werror
+
+obj-y += hier_ictlr.o
+
diff --git a/drivers/platform/tegra/hier_ictlr/hier_ictlr.c b/drivers/platform/tegra/hier_ictlr/hier_ictlr.c
new file mode 100644
index 000000000000..5e565d0aa090
--- /dev/null
+++ b/drivers/platform/tegra/hier_ictlr/hier_ictlr.c
@@ -0,0 +1,192 @@
+/*
+ * Copyright (c) 2013-2014, 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 as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+
+#define HIER_GROUP_CPU_ENABLE                                 0x00000000
+#define HIER_GROUP_CPU_STATUS                                 0x00000004
+#define HIER_GROUP1_MSELECT_ERROR                                     15
+
+#define MSELECT_CONFIG_0                                             0x0
+#define MSELECT_CONFIG_0_READ_TIMEOUT_EN_SLAVE0_SHIFT                 16
+#define MSELECT_CONFIG_0_WRITE_TIMEOUT_EN_SLAVE0_SHIFT                17
+#define MSELECT_CONFIG_0_READ_TIMEOUT_EN_SLAVE1_SHIFT                 18
+#define MSELECT_CONFIG_0_WRITE_TIMEOUT_EN_SLAVE1_SHIFT                19
+#define MSELECT_CONFIG_0_READ_TIMEOUT_EN_SLAVE2_SHIFT                 20
+#define MSELECT_CONFIG_0_WRITE_TIMEOUT_EN_SLAVE2_SHIFT                21
+#define MSELECT_CONFIG_0_ERR_RESP_EN_SLAVE1_SHIFT                     24
+#define MSELECT_CONFIG_0_ERR_RESP_EN_SLAVE2_SHIFT                     25
+
+#define MSELECT_TIMEOUT_TIMER_0                                     0x5c
+#define MSELECT_ERROR_STATUS_0                                      0x60
+
+struct tegra_hier_ictlr {
+	u32 irq;
+	void __iomem *hier_ictlr_base;
+	void __iomem *mselect_base;
+};
+
+static irqreturn_t tegra_hier_ictlr_irq_handler(int irq, void *data)
+{
+	struct device *dev = data;
+	struct tegra_hier_ictlr *ictlr = dev_get_drvdata(dev);
+	unsigned long status;
+
+	status = readl(ictlr->mselect_base + MSELECT_ERROR_STATUS_0);
+	if (status != 0) {
+		pr_err("MSELECT error detected! status=0x%x\n",
+			(unsigned int)status);
+		BUG();
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int tegra_hier_ictlr_map_memory(struct platform_device *pdev,
+				       struct tegra_hier_ictlr *ictlr)
+{
+	struct resource *res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev,
+			"Unable to allocate resources (hier-ictlr).\n");
+		return -EBUSY;
+	}
+
+	ictlr->hier_ictlr_base = devm_request_and_ioremap(&pdev->dev, res);
+	if (!ictlr->hier_ictlr_base) {
+		dev_err(&pdev->dev, "Unable to map memory (hier-ictlr).\n");
+		return -EBUSY;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!res) {
+		dev_err(&pdev->dev,
+		    "Unable to allocate resources (mselect).\n");
+		return -EBUSY;
+	}
+
+	ictlr->mselect_base = devm_request_and_ioremap(&pdev->dev, res);
+	if (!ictlr->mselect_base) {
+		dev_err(&pdev->dev, "Unable to map memory (mselect).\n");
+		return -EBUSY;
+	}
+
+	return 0;
+}
+
+static int tegra_hier_ictlr_irq_init(struct platform_device *pdev,
+				     struct tegra_hier_ictlr *ictlr)
+{
+	unsigned long reg;
+	int ret;
+
+	ictlr->irq = platform_get_irq(pdev, 0);
+	if (ictlr->irq <= 0)
+		return -EBUSY;
+
+	ret = devm_request_irq(&pdev->dev, ictlr->irq,
+		tegra_hier_ictlr_irq_handler, IRQF_TRIGGER_HIGH,
+		"hier_ictlr_irq", &pdev->dev);
+
+	if (ret) {
+		dev_err(&pdev->dev,
+			"Unable to request interrupt for device (err=%d).\n",
+			ret);
+		return ret;
+	}
+
+	reg = readl(ictlr->hier_ictlr_base + HIER_GROUP_CPU_ENABLE);
+	writel(reg | (1 << HIER_GROUP1_MSELECT_ERROR),
+		ictlr->hier_ictlr_base + HIER_GROUP_CPU_ENABLE);
+
+	return 0;
+}
+
+static int tegra_hier_ictlr_mselect_init(struct platform_device *pdev,
+					 struct tegra_hier_ictlr *ictlr)
+{
+	unsigned long reg;
+
+	writel(0xFFFFFF, ictlr->mselect_base + MSELECT_TIMEOUT_TIMER_0);
+
+	reg = readl(ictlr->mselect_base + MSELECT_CONFIG_0);
+	writel(reg |
+		((1 << MSELECT_CONFIG_0_READ_TIMEOUT_EN_SLAVE0_SHIFT)  |
+		 (1 << MSELECT_CONFIG_0_WRITE_TIMEOUT_EN_SLAVE0_SHIFT) |
+		 (1 << MSELECT_CONFIG_0_READ_TIMEOUT_EN_SLAVE1_SHIFT)  |
+		 (1 << MSELECT_CONFIG_0_WRITE_TIMEOUT_EN_SLAVE1_SHIFT) |
+		 (1 << MSELECT_CONFIG_0_READ_TIMEOUT_EN_SLAVE2_SHIFT)  |
+		 (1 << MSELECT_CONFIG_0_WRITE_TIMEOUT_EN_SLAVE2_SHIFT) |
+		 (1 << MSELECT_CONFIG_0_ERR_RESP_EN_SLAVE1_SHIFT)      |
+		 (1 << MSELECT_CONFIG_0_ERR_RESP_EN_SLAVE2_SHIFT)),
+		ictlr->hier_ictlr_base + MSELECT_CONFIG_0);
+
+	return 0;
+}
+
+static int tegra_hier_ictlr_probe(struct platform_device *pdev)
+{
+	struct tegra_hier_ictlr *ictlr;
+	int ret;
+
+	ictlr = devm_kzalloc(&pdev->dev, sizeof(struct tegra_hier_ictlr),
+		GFP_KERNEL);
+	if (!ictlr)
+		return -ENOMEM;
+
+	ret = tegra_hier_ictlr_map_memory(pdev, ictlr);
+	if (ret)
+		return ret;
+
+	ret = tegra_hier_ictlr_mselect_init(pdev, ictlr);
+	if (ret)
+		return ret;
+
+	ret = tegra_hier_ictlr_irq_init(pdev, ictlr);
+	if (ret)
+		return ret;
+
+	dev_notice(&pdev->dev, "probed\n");
+
+	dev_set_drvdata(&pdev->dev, ictlr);
+	return 0;
+}
+
+static struct platform_driver tegra_hier_ictlr_driver = {
+	.driver = {
+		   .name = "tegra-hier-ictlr",
+		   .owner = THIS_MODULE,
+		   },
+	.probe = tegra_hier_ictlr_probe,
+};
+
+static int __init tegra_hier_ictlr_init(void)
+{
+	return platform_driver_register(&tegra_hier_ictlr_driver);
+}
+
+module_init(tegra_hier_ictlr_init);
+
+MODULE_DESCRIPTION("Tegra Hierarchical Interrupt Controller Driver");
+MODULE_LICENSE("GPL v2");