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. Some of configuration param could be passed from DT too. Signed-off-by: Hiroshi DOYU <hdoyu@xxxxxxxxxx> Cc: Felipe Balbi <balbi@xxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> --- v4: Fixed the comments from Felipe/Russell. This is now located under drivers/platform/arm. v3: Use platform_device to get info from dt dynamically.(Felipe/Arnd) Signed-off-by: Hiroshi DOYU <hdoyu@xxxxxxxxxx> --- drivers/platform/Kconfig | 5 + drivers/platform/Makefile | 1 + drivers/platform/arm/Kconfig | 8 + drivers/platform/arm/Makefile | 5 + drivers/platform/arm/tegra-ahb.c | 278 ++++++++++++++++++++++++++++++++++++++ 5 files changed, 297 insertions(+), 0 deletions(-) diff --git a/drivers/platform/Kconfig b/drivers/platform/Kconfig index 8390dca..8b96a77 100644 --- a/drivers/platform/Kconfig +++ b/drivers/platform/Kconfig @@ -1,3 +1,8 @@ if X86 source "drivers/platform/x86/Kconfig" endif + +if ARM +source "drivers/platform/arm/Kconfig" +endif + diff --git a/drivers/platform/Makefile b/drivers/platform/Makefile index 782953a..7a2b16f 100644 --- a/drivers/platform/Makefile +++ b/drivers/platform/Makefile @@ -3,3 +3,4 @@ # obj-$(CONFIG_X86) += x86/ +obj-$(CONFIG_ARM) += arm/ diff --git a/drivers/platform/arm/Kconfig b/drivers/platform/arm/Kconfig new file mode 100644 index 0000000..0af31db --- /dev/null +++ b/drivers/platform/arm/Kconfig @@ -0,0 +1,8 @@ +config TEGRA_AHB + bool "Enable AHB driver for NVIDIA Tegra SoCs" + depends on ARCH_TEGRA + default y + help + Adds AHB configuration functionality for NVIDIA Tegra SoCs, + which controls AHB bus master arbitration and some + perfomance parameters(priority, prefech size). diff --git a/drivers/platform/arm/Makefile b/drivers/platform/arm/Makefile new file mode 100644 index 0000000..3535f56 --- /dev/null +++ b/drivers/platform/arm/Makefile @@ -0,0 +1,5 @@ +# +# Makefile for linux/drivers/platform/arm +# ARM Platform-Specific Drivers +# +obj-$(CONFIG_TEGRA_AHB) += tegra-ahb.o diff --git a/drivers/platform/arm/tegra-ahb.c b/drivers/platform/arm/tegra-ahb.c new file mode 100644 index 0000000..dcad2ec --- /dev/null +++ b/drivers/platform/arm/tegra-ahb.c @@ -0,0 +1,278 @@ +/* + * 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 + +static u32 tegra_ahb_gizmo[] = { + AHB_ARBITRATION_DISABLE, + AHB_ARBITRATION_PRIORITY_CTRL, + AHB_GIZMO_AHB_MEM, + AHB_GIZMO_APB_DMA, + AHB_GIZMO_IDE, + AHB_GIZMO_USB, + AHB_GIZMO_AHB_XBAR_BRIDGE, + AHB_GIZMO_CPU_AHB_BRIDGE, + AHB_GIZMO_COP_AHB_BRIDGE, + AHB_GIZMO_XBAR_APB_CTLR, + AHB_GIZMO_VCP_AHB_BRIDGE, + AHB_GIZMO_NAND, + AHB_GIZMO_SDMMC4, + AHB_GIZMO_XIO, + AHB_GIZMO_BSEV, + AHB_GIZMO_BSEA, + AHB_GIZMO_NOR, + AHB_GIZMO_USB2, + AHB_GIZMO_USB3, + AHB_GIZMO_SDMMC1, + AHB_GIZMO_SDMMC2, + AHB_GIZMO_SDMMC3, + AHB_MEM_PREFETCH_CFG_X, + AHB_ARBITRATION_XBAR_CTRL, + AHB_MEM_PREFETCH_CFG3, + AHB_MEM_PREFETCH_CFG4, + AHB_MEM_PREFETCH_CFG1, + AHB_MEM_PREFETCH_CFG2, + AHB_ARBITRATION_AHB_MEM_WRQUE_MST_ID, +}; + +struct tegra_ahb { + void __iomem *regs; + void *ctx; + struct device *dev; +}; + +static inline u32 gizmo_readl(struct tegra_ahb *ahb, u32 offset) +{ + return readl(ahb->regs + offset); +} + +static inline void gizmo_writel(struct tegra_ahb *ahb, u32 value, u32 offset) +{ + writel(value, ahb->regs + offset); +} + +static int tegra_ahb_suspend(struct device *dev) +{ + int i; + struct tegra_ahb *ahb = dev_get_drvdata(dev); + u32 *p = ahb->ctx; + + for (i = 0; i < ARRAY_SIZE(tegra_ahb_gizmo); i++) + p[i] = gizmo_readl(ahb, tegra_ahb_gizmo[i]); + return 0; +} + +static int tegra_ahb_resume(struct device *dev) +{ + int i; + struct tegra_ahb *ahb = dev_get_drvdata(dev); + u32 *p = ahb->ctx; + + for (i = 0; i < ARRAY_SIZE(tegra_ahb_gizmo); i++) + gizmo_writel(ahb, p[i], tegra_ahb_gizmo[i]); + return 0; +} + +static UNIVERSAL_DEV_PM_OPS(tegra_ahb_pm, + tegra_ahb_suspend, + tegra_ahb_resume, NULL); + +static void tegra_ahb_gizmo_init(struct tegra_ahb *ahb) +{ + u32 val; + + val = gizmo_readl(ahb, AHB_GIZMO_AHB_MEM); + val |= ENB_FAST_REARBITRATE | IMMEDIATE | DONT_SPLIT_AHB_WR; + gizmo_writel(ahb, val, AHB_GIZMO_AHB_MEM); + + val = gizmo_readl(ahb, AHB_GIZMO_USB); + val |= IMMEDIATE; + gizmo_writel(ahb, val, AHB_GIZMO_USB); + + val = gizmo_readl(ahb, AHB_GIZMO_USB2); + val |= IMMEDIATE; + gizmo_writel(ahb, val, AHB_GIZMO_USB2); + + val = gizmo_readl(ahb, AHB_GIZMO_USB3); + val |= IMMEDIATE; + gizmo_writel(ahb, val, AHB_GIZMO_USB3); + + val = gizmo_readl(ahb, AHB_ARBITRATION_PRIORITY_CTRL); + val |= PRIORITY_SELECT_USB | + PRIORITY_SELECT_USB2 | + PRIORITY_SELECT_USB3 | + AHB_PRIORITY_WEIGHT(7); + gizmo_writel(ahb, val, AHB_ARBITRATION_PRIORITY_CTRL); + + val = gizmo_readl(ahb, AHB_MEM_PREFETCH_CFG1); + val &= ~MST_ID(~0); + val |= PREFETCH_ENB | + AHBDMA_MST_ID | + ADDR_BNDRY(0xc) | + INACTIVITY_TIMEOUT(0x1000); + gizmo_writel(ahb, val, AHB_MEM_PREFETCH_CFG1); + + val = gizmo_readl(ahb, AHB_MEM_PREFETCH_CFG2); + val &= ~MST_ID(~0); + val |= PREFETCH_ENB | + USB_MST_ID | + ADDR_BNDRY(0xc) | + INACTIVITY_TIMEOUT(0x1000); + gizmo_writel(ahb, val, AHB_MEM_PREFETCH_CFG2); + + val = gizmo_readl(ahb, AHB_MEM_PREFETCH_CFG3); + val &= ~MST_ID(~0); + val |= PREFETCH_ENB | + USB3_MST_ID | + ADDR_BNDRY(0xc) | + INACTIVITY_TIMEOUT(0x1000); + gizmo_writel(ahb, val, AHB_MEM_PREFETCH_CFG3); + + val = gizmo_readl(ahb, AHB_MEM_PREFETCH_CFG4); + val &= ~MST_ID(~0); + val |= PREFETCH_ENB | + USB2_MST_ID | + ADDR_BNDRY(0xc) | + INACTIVITY_TIMEOUT(0x1000); + gizmo_writel(ahb, val, AHB_MEM_PREFETCH_CFG4); +} + +static int __devinit tegra_ahb_probe(struct platform_device *pdev) +{ + struct resource *res; + struct tegra_ahb *ahb; + size_t bytes; + + bytes = sizeof(*ahb) + sizeof(u32) * ARRAY_SIZE(tegra_ahb_gizmo); + ahb = devm_kzalloc(&pdev->dev, bytes, GFP_KERNEL); + if (!ahb) + return -ENOMEM; + ahb->ctx = ahb + 1; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + ahb->regs = devm_request_and_ioremap(&pdev->dev, res); + if (!ahb->regs) + return -EBUSY; + + ahb->dev = &pdev->dev; + platform_set_drvdata(pdev, ahb); + tegra_ahb_gizmo_init(ahb); + return 0; +} + +static int __devexit tegra_ahb_remove(struct platform_device *pdev) +{ + platform_set_drvdata(pdev, NULL); + return 0; +} + +static const struct of_device_id tegra_ahb_of_match[] __devinitconst = { + { .compatible = "nvidia,tegra30-ahb", }, + { .compatible = "nvidia,tegra20-ahb", }, + {}, +}; + +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, + }, +}; + +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); 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