diff options
Diffstat (limited to 'drivers/dma/hsu/pci.c')
| -rw-r--r-- | drivers/dma/hsu/pci.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/drivers/dma/hsu/pci.c b/drivers/dma/hsu/pci.c new file mode 100644 index 000000000..78836526d --- /dev/null +++ b/drivers/dma/hsu/pci.c @@ -0,0 +1,147 @@ +/* + * PCI driver for the High Speed UART DMA + * + * Copyright (C) 2015 Intel Corporation + * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com> + * + * Partially based on the bits found in drivers/tty/serial/mfd.c. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/bitops.h> +#include <linux/device.h> +#include <linux/module.h> +#include <linux/pci.h> + +#include "hsu.h" + +#define HSU_PCI_DMASR 0x00 +#define HSU_PCI_DMAISR 0x04 + +#define HSU_PCI_CHAN_OFFSET 0x100 + +#define PCI_DEVICE_ID_INTEL_MFLD_HSU_DMA 0x081e +#define PCI_DEVICE_ID_INTEL_MRFLD_HSU_DMA 0x1192 + +static irqreturn_t hsu_pci_irq(int irq, void *dev) +{ + struct hsu_dma_chip *chip = dev; + u32 dmaisr; + u32 status; + unsigned short i; + int ret = 0; + int err; + + dmaisr = readl(chip->regs + HSU_PCI_DMAISR); + for (i = 0; i < chip->hsu->nr_channels; i++) { + if (dmaisr & 0x1) { + err = hsu_dma_get_status(chip, i, &status); + if (err > 0) + ret |= 1; + else if (err == 0) + ret |= hsu_dma_do_irq(chip, i, status); + } + dmaisr >>= 1; + } + + return IRQ_RETVAL(ret); +} + +static int hsu_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) +{ + struct hsu_dma_chip *chip; + int ret; + + ret = pcim_enable_device(pdev); + if (ret) + return ret; + + ret = pcim_iomap_regions(pdev, BIT(0), pci_name(pdev)); + if (ret) { + dev_err(&pdev->dev, "I/O memory remapping failed\n"); + return ret; + } + + pci_set_master(pdev); + pci_try_set_mwi(pdev); + + ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32)); + if (ret) + return ret; + + ret = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32)); + if (ret) + return ret; + + chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL); + if (!chip) + return -ENOMEM; + + ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES); + if (ret < 0) + return ret; + + chip->dev = &pdev->dev; + chip->regs = pcim_iomap_table(pdev)[0]; + chip->length = pci_resource_len(pdev, 0); + chip->offset = HSU_PCI_CHAN_OFFSET; + chip->irq = pci_irq_vector(pdev, 0); + + ret = hsu_dma_probe(chip); + if (ret) + return ret; + + ret = request_irq(chip->irq, hsu_pci_irq, 0, "hsu_dma_pci", chip); + if (ret) + goto err_register_irq; + + /* + * On Intel Tangier B0 and Anniedale the interrupt line, disregarding + * to have different numbers, is shared between HSU DMA and UART IPs. + * Thus on such SoCs we are expecting that IRQ handler is called in + * UART driver only. Instead of handling the spurious interrupt + * from HSU DMA here and waste CPU time and delay HSU UART interrupt + * handling, disable the interrupt entirely. + */ + if (pdev->device == PCI_DEVICE_ID_INTEL_MRFLD_HSU_DMA) + disable_irq_nosync(chip->irq); + + pci_set_drvdata(pdev, chip); + + return 0; + +err_register_irq: + hsu_dma_remove(chip); + return ret; +} + +static void hsu_pci_remove(struct pci_dev *pdev) +{ + struct hsu_dma_chip *chip = pci_get_drvdata(pdev); + + free_irq(chip->irq, chip); + hsu_dma_remove(chip); +} + +static const struct pci_device_id hsu_pci_id_table[] = { + { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MFLD_HSU_DMA), 0 }, + { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MRFLD_HSU_DMA), 0 }, + { } +}; +MODULE_DEVICE_TABLE(pci, hsu_pci_id_table); + +static struct pci_driver hsu_pci_driver = { + .name = "hsu_dma_pci", + .id_table = hsu_pci_id_table, + .probe = hsu_pci_probe, + .remove = hsu_pci_remove, +}; + +module_pci_driver(hsu_pci_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("High Speed UART DMA PCI driver"); +MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>"); |