The AHB Bus conforms to the AMBA Specification (Rev 2.0) Advanced
High-performance Bus (AHB) architecture.
The AHB Arbiter controls AHB bus master arbitration. This effectively
forms a second level of arbitration for access to the memory
controller through the AHB Slave Memory device. The AHB pre-fetch
logic can be configured to enhance performance for devices doing
sequential access. Each AHB master is assigned to either the high or
low priority bin. Both Tegra20/30 have this AHB bus.
Signed-off-by: Hiroshi DOYU <hdoyu@xxxxxxxxxx>
Cc: Felipe Balbi <balbi@xxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
---
Update:
- Use platform_device to get info from dt dynamically.(Felipe/Arnd)
---
arch/arm/mach-tegra/Makefile | 1 +
arch/arm/mach-tegra/tegra-ahb.c | 285 +++++++++++++++++++++++++++++++++++++++
2 files changed, 286 insertions(+), 0 deletions(-)
diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile
index 2eb4445..f6c8237 100644
--- a/arch/arm/mach-tegra/Makefile
+++ b/arch/arm/mach-tegra/Makefile
@@ -1,3 +1,4 @@
+obj-y += tegra-ahb.o
obj-y += board-pinmux.o
obj-y += common.o
obj-y += devices.o
diff --git a/arch/arm/mach-tegra/tegra-ahb.c b/arch/arm/mach-tegra/tegra-ahb.c
new file mode 100644
index 0000000..71b5950
--- /dev/null
+++ b/arch/arm/mach-tegra/tegra-ahb.c
@@ -0,0 +1,285 @@
+/*
+ * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * Author:
+ * Jay Cheng <jacheng@xxxxxxxxxx>
+ * James Wylder <james.wylder@xxxxxxxxxxxx>
+ * Benoit Goby <benoit@xxxxxxxxxxx>
+ * Colin Cross <ccross@xxxxxxxxxxx>
+ * Hiroshi DOYU <hdoyu@xxxxxxxxxx>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+
+#include <mach/iomap.h>
+
+#define DRV_NAME "tegra-ahb"
+
+#define AHB_ARBITRATION_DISABLE 0x00
+#define AHB_ARBITRATION_PRIORITY_CTRL 0x04
+#define AHB_PRIORITY_WEIGHT(x) (((x) & 0x7) << 29)
+#define PRIORITY_SELECT_USB BIT(6)
+#define PRIORITY_SELECT_USB2 BIT(18)
+#define PRIORITY_SELECT_USB3 BIT(17)
+
+#define AHB_GIZMO_AHB_MEM 0x0c
+#define ENB_FAST_REARBITRATE BIT(2)
+#define DONT_SPLIT_AHB_WR BIT(7)
+
+#define AHB_GIZMO_APB_DMA 0x10
+#define AHB_GIZMO_IDE 0x18
+#define AHB_GIZMO_USB 0x1c
+#define AHB_GIZMO_AHB_XBAR_BRIDGE 0x20
+#define AHB_GIZMO_CPU_AHB_BRIDGE 0x24
+#define AHB_GIZMO_COP_AHB_BRIDGE 0x28
+#define AHB_GIZMO_XBAR_APB_CTLR 0x2c
+#define AHB_GIZMO_VCP_AHB_BRIDGE 0x30
+#define AHB_GIZMO_NAND 0x3c
+#define AHB_GIZMO_SDMMC4 0x44
+#define AHB_GIZMO_XIO 0x48
+#define AHB_GIZMO_BSEV 0x60
+#define AHB_GIZMO_BSEA 0x70
+#define AHB_GIZMO_NOR 0x74
+#define AHB_GIZMO_USB2 0x78
+#define AHB_GIZMO_USB3 0x7c
+#define IMMEDIATE BIT(18)
+
+#define AHB_GIZMO_SDMMC1 0x80
+#define AHB_GIZMO_SDMMC2 0x84
+#define AHB_GIZMO_SDMMC3 0x88
+#define AHB_MEM_PREFETCH_CFG_X 0xd8
+#define AHB_ARBITRATION_XBAR_CTRL 0xdc
+#define AHB_MEM_PREFETCH_CFG3 0xe0
+#define AHB_MEM_PREFETCH_CFG4 0xe4
+#define AHB_MEM_PREFETCH_CFG1 0xec
+#define AHB_MEM_PREFETCH_CFG2 0xf0
+#define PREFETCH_ENB BIT(31)
+#define MST_ID(x) (((x) & 0x1f) << 26)
+#define AHBDMA_MST_ID MST_ID(5)
+#define USB_MST_ID MST_ID(6)
+#define USB2_MST_ID MST_ID(18)
+#define USB3_MST_ID MST_ID(17)
+#define ADDR_BNDRY(x) (((x) & 0xf) << 21)
+#define INACTIVITY_TIMEOUT(x) (((x) & 0xffff) << 0)
+
+#define AHB_ARBITRATION_AHB_MEM_WRQUE_MST_ID 0xf8
+
+struct __tegra_ahb {
+ void __iomem *regs;
+ struct device *dev;
+};
+
+static struct __tegra_ahb *tegra_ahb;
+
+static inline unsigned long gizmo_readl(unsigned long offset)
+{
+ return readl(tegra_ahb->regs + offset);
+}
+
+static inline void gizmo_writel(unsigned long value, unsigned long offset)
+{
+ writel(value, tegra_ahb->regs + offset);
+}
+
+struct __ahb_gizmo {
+ unsigned long offset;
+ unsigned long data;
+};
+
+static struct __ahb_gizmo ahb_gizmo[] = {
+ { .offset = AHB_ARBITRATION_DISABLE, },
+ { .offset = AHB_ARBITRATION_PRIORITY_CTRL, },
+ { .offset = AHB_GIZMO_AHB_MEM, },
+ { .offset = AHB_GIZMO_APB_DMA, },
+ { .offset = AHB_GIZMO_IDE, },
+ { .offset = AHB_GIZMO_USB, },
+ { .offset = AHB_GIZMO_AHB_XBAR_BRIDGE, },
+ { .offset = AHB_GIZMO_CPU_AHB_BRIDGE, },
+ { .offset = AHB_GIZMO_COP_AHB_BRIDGE, },
+ { .offset = AHB_GIZMO_XBAR_APB_CTLR, },
+ { .offset = AHB_GIZMO_VCP_AHB_BRIDGE, },
+ { .offset = AHB_GIZMO_NAND, },
+ { .offset = AHB_GIZMO_SDMMC4, },
+ { .offset = AHB_GIZMO_XIO, },
+ { .offset = AHB_GIZMO_BSEV, },
+ { .offset = AHB_GIZMO_BSEA, },
+ { .offset = AHB_GIZMO_NOR, },
+ { .offset = AHB_GIZMO_USB2, },
+ { .offset = AHB_GIZMO_USB3, },
+ { .offset = AHB_GIZMO_SDMMC1, },
+ { .offset = AHB_GIZMO_SDMMC2, },
+ { .offset = AHB_GIZMO_SDMMC3, },
+ { .offset = AHB_MEM_PREFETCH_CFG_X, },
+ { .offset = AHB_ARBITRATION_XBAR_CTRL, },
+ { .offset = AHB_MEM_PREFETCH_CFG3, },
+ { .offset = AHB_MEM_PREFETCH_CFG4, },
+ { .offset = AHB_MEM_PREFETCH_CFG1, },
+ { .offset = AHB_MEM_PREFETCH_CFG2, },
+ { .offset = AHB_ARBITRATION_AHB_MEM_WRQUE_MST_ID, },
+};
+
+static int tegra_ahb_suspend(struct device *dev)
+{
+ int i;
+ for (i = 0; i < ARRAY_SIZE(ahb_gizmo); i++)
+ ahb_gizmo[i].data = gizmo_readl(ahb_gizmo[i].offset);
+ return 0;
+}
+
+static int tegra_ahb_resume(struct device *dev)
+{
+ int i;
+ for (i = 0; i < ARRAY_SIZE(ahb_gizmo); i++)
+ gizmo_writel(ahb_gizmo[i].data, ahb_gizmo[i].offset);
+ return 0;
+}
+
+static void tegra_ahb_gizmo_init(void)
+{
+ unsigned long val;
+
+ val = gizmo_readl(AHB_GIZMO_AHB_MEM);
+ val |= ENB_FAST_REARBITRATE | IMMEDIATE | DONT_SPLIT_AHB_WR;
+ gizmo_writel(val, AHB_GIZMO_AHB_MEM);
+
+ val = gizmo_readl(AHB_GIZMO_USB);
+ val |= IMMEDIATE;
+ gizmo_writel(val, AHB_GIZMO_USB);
+
+ val = gizmo_readl(AHB_GIZMO_USB2);
+ val |= IMMEDIATE;
+ gizmo_writel(val, AHB_GIZMO_USB2);
+
+ val = gizmo_readl(AHB_GIZMO_USB3);
+ val |= IMMEDIATE;
+ gizmo_writel(val, AHB_GIZMO_USB3);
+
+ val = gizmo_readl(AHB_ARBITRATION_PRIORITY_CTRL);
+ val |= PRIORITY_SELECT_USB |
+ PRIORITY_SELECT_USB2 |
+ PRIORITY_SELECT_USB3 |
+ AHB_PRIORITY_WEIGHT(7);
+ gizmo_writel(val, AHB_ARBITRATION_PRIORITY_CTRL);
+
+ val = gizmo_readl(AHB_MEM_PREFETCH_CFG1);
+ val &= ~MST_ID(~0);
+ val |= PREFETCH_ENB |
+ AHBDMA_MST_ID |
+ ADDR_BNDRY(0xc) |
+ INACTIVITY_TIMEOUT(0x1000);
+ gizmo_writel(val, AHB_MEM_PREFETCH_CFG1);
+
+ val = gizmo_readl(AHB_MEM_PREFETCH_CFG2);
+ val &= ~MST_ID(~0);
+ val |= PREFETCH_ENB |
+ USB_MST_ID |
+ ADDR_BNDRY(0xc) |
+ INACTIVITY_TIMEOUT(0x1000);
+ gizmo_writel(val, AHB_MEM_PREFETCH_CFG2);
+
+ val = gizmo_readl(AHB_MEM_PREFETCH_CFG3);
+ val &= ~MST_ID(~0);
+ val |= PREFETCH_ENB |
+ USB3_MST_ID |
+ ADDR_BNDRY(0xc) |
+ INACTIVITY_TIMEOUT(0x1000);
+ gizmo_writel(val, AHB_MEM_PREFETCH_CFG3);
+
+ val = gizmo_readl(AHB_MEM_PREFETCH_CFG4);
+ val &= ~MST_ID(~0);
+ val |= PREFETCH_ENB |
+ USB2_MST_ID |
+ ADDR_BNDRY(0xc) |
+ INACTIVITY_TIMEOUT(0x1000);
+ gizmo_writel(val, AHB_MEM_PREFETCH_CFG4);
+}
+
+static int __devinit tegra_ahb_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+
+ if (tegra_ahb)
+ return -ENODEV;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENODEV;
+
+ res = devm_request_mem_region(&pdev->dev, res->start,
+ resource_size(res), dev_name(&pdev->dev));
+ if (!res)
+ return -EBUSY;
+
+ tegra_ahb = devm_kzalloc(&pdev->dev, sizeof(*tegra_ahb), GFP_KERNEL);
+ if (!tegra_ahb)
+ return -ENOMEM;
+ tegra_ahb->dev = &pdev->dev;
+ tegra_ahb->regs = devm_ioremap(&pdev->dev,
+ res->start, resource_size(res));
+ if (!tegra_ahb->regs) {
+ tegra_ahb = NULL;
+ return -ENOMEM;
+ }
+ platform_set_drvdata(pdev, tegra_ahb);
+ tegra_ahb_gizmo_init();
+ return 0;
+}
+
+static int __devexit tegra_ahb_remove(struct platform_device *pdev)
+{
+ platform_set_drvdata(pdev, NULL);
+ tegra_ahb = NULL;
+ return 0;
+}
+
+static const struct of_device_id tegra_ahb_of_match[] __devinitconst = {
+ { .compatible = "nvidia,tegra30-ahb", },
+ { .compatible = "nvidia,tegra20-ahb", },
+ {},
+};
+
+static const struct dev_pm_ops tegra_ahb_pm_ops __devinitconst = {
+ SET_RUNTIME_PM_OPS(tegra_ahb_suspend, tegra_ahb_resume, NULL)
+};
+
+static struct platform_driver tegra_ahb_driver = {
+ .probe = tegra_ahb_probe,
+ .remove = __devexit_p(tegra_ahb_remove),
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ .of_match_table = tegra_ahb_of_match,
+ .pm = &tegra_ahb_pm_ops,
+ },
+};
+
+static int __init tegra_ahb_init(void)
+{
+ return platform_driver_register(&tegra_ahb_driver);
+}
+postcore_initcall(tegra_ahb_init);
+
+static void __exit tegra_ahb_exit(void)
+{
+ platform_driver_unregister(&tegra_ahb_driver);
+}
+module_exit(tegra_ahb_exit);
+
+MODULE_AUTHOR("Hiroshi DOYU <hdoyu@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Tegra AHB driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRV_NAME);
--
1.7.5.4
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