diff options
Diffstat (limited to 'arch/x86/pci/sta2x11-fixup.c')
| -rw-r--r-- | arch/x86/pci/sta2x11-fixup.c | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/arch/x86/pci/sta2x11-fixup.c b/arch/x86/pci/sta2x11-fixup.c new file mode 100644 index 000000000..7368afc03 --- /dev/null +++ b/arch/x86/pci/sta2x11-fixup.c @@ -0,0 +1,232 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * DMA translation between STA2x11 AMBA memory mapping and the x86 memory mapping + * + * ST Microelectronics ConneXt (STA2X11/STA2X10) + * + * Copyright (c) 2010-2011 Wind River Systems, Inc. + */ + +#include <linux/pci.h> +#include <linux/pci_ids.h> +#include <linux/export.h> +#include <linux/list.h> +#include <linux/dma-map-ops.h> +#include <linux/swiotlb.h> +#include <asm/iommu.h> + +#define STA2X11_SWIOTLB_SIZE (4*1024*1024) + +/* + * We build a list of bus numbers that are under the ConneXt. The + * main bridge hosts 4 busses, which are the 4 endpoints, in order. + */ +#define STA2X11_NR_EP 4 /* 0..3 included */ +#define STA2X11_NR_FUNCS 8 /* 0..7 included */ +#define STA2X11_AMBA_SIZE (512 << 20) + +struct sta2x11_ahb_regs { /* saved during suspend */ + u32 base, pexlbase, pexhbase, crw; +}; + +struct sta2x11_mapping { + int is_suspended; + struct sta2x11_ahb_regs regs[STA2X11_NR_FUNCS]; +}; + +struct sta2x11_instance { + struct list_head list; + int bus0; + struct sta2x11_mapping map[STA2X11_NR_EP]; +}; + +static LIST_HEAD(sta2x11_instance_list); + +/* At probe time, record new instances of this bridge (likely one only) */ +static void sta2x11_new_instance(struct pci_dev *pdev) +{ + struct sta2x11_instance *instance; + + instance = kzalloc(sizeof(*instance), GFP_ATOMIC); + if (!instance) + return; + /* This has a subordinate bridge, with 4 more-subordinate ones */ + instance->bus0 = pdev->subordinate->number + 1; + + if (list_empty(&sta2x11_instance_list)) { + int size = STA2X11_SWIOTLB_SIZE; + /* First instance: register your own swiotlb area */ + dev_info(&pdev->dev, "Using SWIOTLB (size %i)\n", size); + if (swiotlb_init_late(size, GFP_DMA, NULL)) + dev_emerg(&pdev->dev, "init swiotlb failed\n"); + } + list_add(&instance->list, &sta2x11_instance_list); +} +DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, 0xcc17, sta2x11_new_instance); + +/* + * Utility functions used in this file from below + */ +static struct sta2x11_instance *sta2x11_pdev_to_instance(struct pci_dev *pdev) +{ + struct sta2x11_instance *instance; + int ep; + + list_for_each_entry(instance, &sta2x11_instance_list, list) { + ep = pdev->bus->number - instance->bus0; + if (ep >= 0 && ep < STA2X11_NR_EP) + return instance; + } + return NULL; +} + +static int sta2x11_pdev_to_ep(struct pci_dev *pdev) +{ + struct sta2x11_instance *instance; + + instance = sta2x11_pdev_to_instance(pdev); + if (!instance) + return -1; + + return pdev->bus->number - instance->bus0; +} + +/* This is exported, as some devices need to access the MFD registers */ +struct sta2x11_instance *sta2x11_get_instance(struct pci_dev *pdev) +{ + return sta2x11_pdev_to_instance(pdev); +} +EXPORT_SYMBOL(sta2x11_get_instance); + +/* At setup time, we use our own ops if the device is a ConneXt one */ +static void sta2x11_setup_pdev(struct pci_dev *pdev) +{ + struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev); + + if (!instance) /* either a sta2x11 bridge or another ST device */ + return; + + /* We must enable all devices as master, for audio DMA to work */ + pci_set_master(pdev); +} +DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_setup_pdev); + +/* + * At boot we must set up the mappings for the pcie-to-amba bridge. + * It involves device access, and the same happens at suspend/resume time + */ + +#define AHB_MAPB 0xCA4 +#define AHB_CRW(i) (AHB_MAPB + 0 + (i) * 0x10) +#define AHB_CRW_SZMASK 0xfffffc00UL +#define AHB_CRW_ENABLE (1 << 0) +#define AHB_CRW_WTYPE_MEM (2 << 1) +#define AHB_CRW_ROE (1UL << 3) /* Relax Order Ena */ +#define AHB_CRW_NSE (1UL << 4) /* No Snoop Enable */ +#define AHB_BASE(i) (AHB_MAPB + 4 + (i) * 0x10) +#define AHB_PEXLBASE(i) (AHB_MAPB + 8 + (i) * 0x10) +#define AHB_PEXHBASE(i) (AHB_MAPB + 12 + (i) * 0x10) + +/* At probe time, enable mapping for each endpoint, using the pdev */ +static void sta2x11_map_ep(struct pci_dev *pdev) +{ + struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev); + struct device *dev = &pdev->dev; + u32 amba_base, max_amba_addr; + int i, ret; + + if (!instance) + return; + + pci_read_config_dword(pdev, AHB_BASE(0), &amba_base); + max_amba_addr = amba_base + STA2X11_AMBA_SIZE - 1; + + ret = dma_direct_set_offset(dev, 0, amba_base, STA2X11_AMBA_SIZE); + if (ret) + dev_err(dev, "sta2x11: could not set DMA offset\n"); + + dev->bus_dma_limit = max_amba_addr; + dma_set_mask_and_coherent(&pdev->dev, max_amba_addr); + + /* Configure AHB mapping */ + pci_write_config_dword(pdev, AHB_PEXLBASE(0), 0); + pci_write_config_dword(pdev, AHB_PEXHBASE(0), 0); + pci_write_config_dword(pdev, AHB_CRW(0), STA2X11_AMBA_SIZE | + AHB_CRW_WTYPE_MEM | AHB_CRW_ENABLE); + + /* Disable all the other windows */ + for (i = 1; i < STA2X11_NR_FUNCS; i++) + pci_write_config_dword(pdev, AHB_CRW(i), 0); + + dev_info(&pdev->dev, + "sta2x11: Map EP %i: AMBA address %#8x-%#8x\n", + sta2x11_pdev_to_ep(pdev), amba_base, max_amba_addr); +} +DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_map_ep); + +#ifdef CONFIG_PM /* Some register values must be saved and restored */ + +static struct sta2x11_mapping *sta2x11_pdev_to_mapping(struct pci_dev *pdev) +{ + struct sta2x11_instance *instance; + int ep; + + instance = sta2x11_pdev_to_instance(pdev); + if (!instance) + return NULL; + ep = sta2x11_pdev_to_ep(pdev); + return instance->map + ep; +} + +static void suspend_mapping(struct pci_dev *pdev) +{ + struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev); + int i; + + if (!map) + return; + + if (map->is_suspended) + return; + map->is_suspended = 1; + + /* Save all window configs */ + for (i = 0; i < STA2X11_NR_FUNCS; i++) { + struct sta2x11_ahb_regs *regs = map->regs + i; + + pci_read_config_dword(pdev, AHB_BASE(i), ®s->base); + pci_read_config_dword(pdev, AHB_PEXLBASE(i), ®s->pexlbase); + pci_read_config_dword(pdev, AHB_PEXHBASE(i), ®s->pexhbase); + pci_read_config_dword(pdev, AHB_CRW(i), ®s->crw); + } +} +DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, suspend_mapping); + +static void resume_mapping(struct pci_dev *pdev) +{ + struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev); + int i; + + if (!map) + return; + + + if (!map->is_suspended) + goto out; + map->is_suspended = 0; + + /* Restore all window configs */ + for (i = 0; i < STA2X11_NR_FUNCS; i++) { + struct sta2x11_ahb_regs *regs = map->regs + i; + + pci_write_config_dword(pdev, AHB_BASE(i), regs->base); + pci_write_config_dword(pdev, AHB_PEXLBASE(i), regs->pexlbase); + pci_write_config_dword(pdev, AHB_PEXHBASE(i), regs->pexhbase); + pci_write_config_dword(pdev, AHB_CRW(i), regs->crw); + } +out: + pci_set_master(pdev); /* Like at boot, enable master on all devices */ +} +DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, resume_mapping); + +#endif /* CONFIG_PM */ |