On Wed, Apr 25, 2012 at 02:07:36PM +0300, Hiroshi DOYU wrote: > 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 > Cc: Felipe Balbi > Cc: Arnd Bergmann > --- > 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 Just one thing, you seem to have missed Russell's comment about this driver being generic. You still add a TEGRA_AHB driver, also, you don't need . Apart from those, you can add: Reviewed-by: Felipe Balbi > --- > 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 > + * James Wylder > + * Benoit Goby > + * Colin Cross > + * Hiroshi DOYU > + * > + * 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 > +#include > +#include > +#include > + > +#include why do you need 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 "); > +MODULE_DESCRIPTION("Tegra AHB driver"); > +MODULE_LICENSE("GPL v2"); > +MODULE_ALIAS("platform:" DRV_NAME); > -- > 1.7.5.4 > -- balbi