diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index a874b6ec6650f..074ffad334a70 100644 --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig @@ -125,6 +125,8 @@ config FSL_DMA EloPlus is on mpc85xx and mpc86xx and Pxxx parts, and the Elo3 is on some Txxx and Bxxx parts. +source "drivers/dma/hsu/Kconfig" + config MPC512X_DMA tristate "Freescale MPC512x built-in DMA engine support" depends on PPC_MPC512x || PPC_MPC831x diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile index f915f61ec5747..bf4485800c60d 100644 --- a/drivers/dma/Makefile +++ b/drivers/dma/Makefile @@ -11,6 +11,7 @@ obj-$(CONFIG_DMATEST) += dmatest.o obj-$(CONFIG_INTEL_IOATDMA) += ioat/ obj-$(CONFIG_INTEL_IOP_ADMA) += iop-adma.o obj-$(CONFIG_FSL_DMA) += fsldma.o +obj-$(CONFIG_HSU_DMA) += hsu/ obj-$(CONFIG_MPC512X_DMA) += mpc512x_dma.o obj-$(CONFIG_PPC_BESTCOMM) += bestcomm/ obj-$(CONFIG_MV_XOR) += mv_xor.o diff --git a/drivers/dma/hsu/Kconfig b/drivers/dma/hsu/Kconfig new file mode 100644 index 0000000000000..7e98eff7440e7 --- /dev/null +++ b/drivers/dma/hsu/Kconfig @@ -0,0 +1,14 @@ +# DMA engine configuration for hsu +config HSU_DMA + tristate "High Speed UART DMA support" + select DMA_ENGINE + select DMA_VIRTUAL_CHANNELS + +config HSU_DMA_PCI + tristate "High Speed UART DMA PCI driver" + depends on PCI + select HSU_DMA + help + Support the High Speed UART DMA on the platfroms that + enumerate it as a PCI device. For example, Intel Medfield + has integrated this HSU DMA controller. diff --git a/drivers/dma/hsu/Makefile b/drivers/dma/hsu/Makefile new file mode 100644 index 0000000000000..b8f9af032ef1e --- /dev/null +++ b/drivers/dma/hsu/Makefile @@ -0,0 +1,5 @@ +obj-$(CONFIG_HSU_DMA) += hsu_dma.o +hsu_dma-objs := hsu.o + +obj-$(CONFIG_HSU_DMA_PCI) += hsu_dma_pci.o +hsu_dma_pci-objs := pci.o diff --git a/drivers/dma/hsu/hsu.c b/drivers/dma/hsu/hsu.c new file mode 100644 index 0000000000000..683ba9b627951 --- /dev/null +++ b/drivers/dma/hsu/hsu.c @@ -0,0 +1,504 @@ +/* + * Core driver for the High Speed UART DMA + * + * Copyright (C) 2015 Intel Corporation + * Author: Andy Shevchenko + * + * 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. + */ + +/* + * DMA channel allocation: + * 1. Even number chans are used for DMA Read (UART TX), odd chans for DMA + * Write (UART RX). + * 2. 0/1 channel are assigned to port 0, 2/3 chan to port 1, 4/5 chan to + * port 3, and so on. + */ + +#include +#include +#include +#include +#include +#include + +#include "hsu.h" + +#define HSU_DMA_BUSWIDTHS \ + BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) | \ + BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \ + BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \ + BIT(DMA_SLAVE_BUSWIDTH_3_BYTES) | \ + BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \ + BIT(DMA_SLAVE_BUSWIDTH_8_BYTES) | \ + BIT(DMA_SLAVE_BUSWIDTH_16_BYTES) + +static inline void hsu_chan_disable(struct hsu_dma_chan *hsuc) +{ + hsu_chan_writel(hsuc, HSU_CH_CR, 0); +} + +static inline void hsu_chan_enable(struct hsu_dma_chan *hsuc) +{ + u32 cr = HSU_CH_CR_CHA; + + if (hsuc->direction == DMA_MEM_TO_DEV) + cr &= ~HSU_CH_CR_CHD; + else if (hsuc->direction == DMA_DEV_TO_MEM) + cr |= HSU_CH_CR_CHD; + + hsu_chan_writel(hsuc, HSU_CH_CR, cr); +} + +static void hsu_dma_chan_start(struct hsu_dma_chan *hsuc) +{ + struct dma_slave_config *config = &hsuc->config; + struct hsu_dma_desc *desc = hsuc->desc; + u32 bsr, mtsr; + u32 dcr = HSU_CH_DCR_CHSOE | HSU_CH_DCR_CHEI; + unsigned int i, count; + + if (hsuc->direction == DMA_MEM_TO_DEV) { + bsr = config->dst_maxburst; + mtsr = config->dst_addr_width; + } else if (hsuc->direction == DMA_DEV_TO_MEM) { + bsr = config->src_maxburst; + mtsr = config->src_addr_width; + } else { + /* Not supported direction */ + return; + } + + hsu_chan_disable(hsuc); + + hsu_chan_writel(hsuc, HSU_CH_DCR, 0); + hsu_chan_writel(hsuc, HSU_CH_BSR, bsr); + hsu_chan_writel(hsuc, HSU_CH_MTSR, mtsr); + + /* Set descriptors */ + count = (desc->nents - desc->active) % HSU_DMA_CHAN_NR_DESC; + for (i = 0; i < count; i++) { + hsu_chan_writel(hsuc, HSU_CH_DxSAR(i), desc->sg[i].addr); + hsu_chan_writel(hsuc, HSU_CH_DxTSR(i), desc->sg[i].len); + + /* Prepare value for DCR */ + dcr |= HSU_CH_DCR_DESCA(i); + dcr |= HSU_CH_DCR_CHTOI(i); /* timeout bit, see HSU Errata 1 */ + + desc->active++; + } + /* Only for the last descriptor in the chain */ + dcr |= HSU_CH_DCR_CHSOD(count - 1); + dcr |= HSU_CH_DCR_CHDI(count - 1); + + hsu_chan_writel(hsuc, HSU_CH_DCR, dcr); + + hsu_chan_enable(hsuc); +} + +static void hsu_dma_stop_channel(struct hsu_dma_chan *hsuc) +{ + unsigned long flags; + + spin_lock_irqsave(&hsuc->lock, flags); + hsu_chan_disable(hsuc); + hsu_chan_writel(hsuc, HSU_CH_DCR, 0); + spin_unlock_irqrestore(&hsuc->lock, flags); +} + +static void hsu_dma_start_channel(struct hsu_dma_chan *hsuc) +{ + unsigned long flags; + + spin_lock_irqsave(&hsuc->lock, flags); + hsu_dma_chan_start(hsuc); + spin_unlock_irqrestore(&hsuc->lock, flags); +} + +static void hsu_dma_start_transfer(struct hsu_dma_chan *hsuc) +{ + struct virt_dma_desc *vdesc; + + /* Get the next descriptor */ + vdesc = vchan_next_desc(&hsuc->vchan); + if (!vdesc) { + hsuc->desc = NULL; + return; + } + + list_del(&vdesc->node); + hsuc->desc = to_hsu_dma_desc(vdesc); + + /* Start the channel with a new descriptor */ + hsu_dma_start_channel(hsuc); +} + +static u32 hsu_dma_chan_get_sr(struct hsu_dma_chan *hsuc) +{ + unsigned long flags; + u32 sr; + + spin_lock_irqsave(&hsuc->lock, flags); + sr = hsu_chan_readl(hsuc, HSU_CH_SR); + spin_unlock_irqrestore(&hsuc->lock, flags); + + return sr; +} + +irqreturn_t hsu_dma_irq(struct hsu_dma_chip *chip, unsigned short nr) +{ + struct hsu_dma_chan *hsuc; + struct hsu_dma_desc *desc; + unsigned long flags; + u32 sr; + + /* Sanity check */ + if (nr >= chip->pdata->nr_channels) + return IRQ_NONE; + + hsuc = &chip->hsu->chan[nr]; + + /* + * No matter what situation, need read clear the IRQ status + * There is a bug, see Errata 5, HSD 2900918 + */ + sr = hsu_dma_chan_get_sr(hsuc); + if (!sr) + return IRQ_NONE; + + /* Timeout IRQ, need wait some time, see Errata 2 */ + if (hsuc->direction == DMA_DEV_TO_MEM && (sr & HSU_CH_SR_DESCTO_ANY)) + udelay(2); + + sr &= ~HSU_CH_SR_DESCTO_ANY; + if (!sr) + return IRQ_HANDLED; + + spin_lock_irqsave(&hsuc->vchan.lock, flags); + desc = hsuc->desc; + if (desc) { + if (sr & HSU_CH_SR_CHE) { + desc->status = DMA_ERROR; + } else if (desc->active < desc->nents) { + hsu_dma_start_channel(hsuc); + } else { + vchan_cookie_complete(&desc->vdesc); + desc->status = DMA_COMPLETE; + hsu_dma_start_transfer(hsuc); + } + } + spin_unlock_irqrestore(&hsuc->vchan.lock, flags); + + return IRQ_HANDLED; +} +EXPORT_SYMBOL_GPL(hsu_dma_irq); + +static struct hsu_dma_desc *hsu_dma_alloc_desc(unsigned int nents) +{ + struct hsu_dma_desc *desc; + + desc = kzalloc(sizeof(*desc), GFP_ATOMIC); + if (!desc) + return NULL; + + desc->sg = kcalloc(nents, sizeof(*desc->sg), GFP_ATOMIC); + if (!desc->sg) { + kfree(desc); + return NULL; + } + + return desc; +} + +static void hsu_dma_desc_free(struct virt_dma_desc *vdesc) +{ + struct hsu_dma_desc *desc = to_hsu_dma_desc(vdesc); + + kfree(desc->sg); + kfree(desc); +} + +static struct dma_async_tx_descriptor *hsu_dma_prep_slave_sg( + struct dma_chan *chan, struct scatterlist *sgl, + unsigned int sg_len, enum dma_transfer_direction direction, + unsigned long flags, void *context) +{ + struct hsu_dma_chan *hsuc = to_hsu_dma_chan(chan); + struct hsu_dma_desc *desc; + struct scatterlist *sg; + unsigned int i; + + desc = hsu_dma_alloc_desc(sg_len); + if (!desc) + return NULL; + + for_each_sg(sgl, sg, sg_len, i) { + desc->sg[i].addr = sg_dma_address(sg); + desc->sg[i].len = sg_dma_len(sg); + } + + desc->nents = sg_len; + desc->direction = direction; + desc->active = 0; + desc->status = DMA_IN_PROGRESS; + + return vchan_tx_prep(&hsuc->vchan, &desc->vdesc, flags); +} + +static void hsu_dma_issue_pending(struct dma_chan *chan) +{ + struct hsu_dma_chan *hsuc = to_hsu_dma_chan(chan); + unsigned long flags; + + spin_lock_irqsave(&hsuc->vchan.lock, flags); + if (vchan_issue_pending(&hsuc->vchan) && !hsuc->desc) + hsu_dma_start_transfer(hsuc); + spin_unlock_irqrestore(&hsuc->vchan.lock, flags); +} + +static size_t hsu_dma_desc_size(struct hsu_dma_desc *desc) +{ + size_t bytes = 0; + unsigned int i; + + for (i = desc->active; i < desc->nents; i++) + bytes += desc->sg[i].len; + + return bytes; +} + +static size_t hsu_dma_active_desc_size(struct hsu_dma_chan *hsuc) +{ + struct hsu_dma_desc *desc = hsuc->desc; + size_t bytes = hsu_dma_desc_size(desc); + int i; + unsigned long flags; + + spin_lock_irqsave(&hsuc->lock, flags); + i = desc->active % HSU_DMA_CHAN_NR_DESC; + do { + bytes += hsu_chan_readl(hsuc, HSU_CH_DxTSR(i)); + } while (--i >= 0); + spin_unlock_irqrestore(&hsuc->lock, flags); + + return bytes; +} + +static enum dma_status hsu_dma_tx_status(struct dma_chan *chan, + dma_cookie_t cookie, struct dma_tx_state *state) +{ + struct hsu_dma_chan *hsuc = to_hsu_dma_chan(chan); + struct virt_dma_desc *vdesc; + enum dma_status status; + size_t bytes; + unsigned long flags; + + status = dma_cookie_status(chan, cookie, state); + if (status == DMA_COMPLETE) + return status; + + spin_lock_irqsave(&hsuc->vchan.lock, flags); + vdesc = vchan_find_desc(&hsuc->vchan, cookie); + if (hsuc->desc && cookie == hsuc->desc->vdesc.tx.cookie) { + bytes = hsu_dma_active_desc_size(hsuc); + dma_set_residue(state, bytes); + status = hsuc->desc->status; + } else if (vdesc) { + bytes = hsu_dma_desc_size(to_hsu_dma_desc(vdesc)); + dma_set_residue(state, bytes); + } + spin_unlock_irqrestore(&hsuc->vchan.lock, flags); + + return status; +} + +static int hsu_dma_slave_config(struct dma_chan *chan, + struct dma_slave_config *config) +{ + struct hsu_dma_chan *hsuc = to_hsu_dma_chan(chan); + + /* Check if chan will be configured for slave transfers */ + if (!is_slave_direction(config->direction)) + return -EINVAL; + + memcpy(&hsuc->config, config, sizeof(hsuc->config)); + + return 0; +} + +static void hsu_dma_chan_deactivate(struct hsu_dma_chan *hsuc) +{ + unsigned long flags; + + spin_lock_irqsave(&hsuc->lock, flags); + hsu_chan_disable(hsuc); + spin_unlock_irqrestore(&hsuc->lock, flags); +} + +static void hsu_dma_chan_activate(struct hsu_dma_chan *hsuc) +{ + unsigned long flags; + + spin_lock_irqsave(&hsuc->lock, flags); + hsu_chan_enable(hsuc); + spin_unlock_irqrestore(&hsuc->lock, flags); +} + +static int hsu_dma_pause(struct dma_chan *chan) +{ + struct hsu_dma_chan *hsuc = to_hsu_dma_chan(chan); + unsigned long flags; + + spin_lock_irqsave(&hsuc->vchan.lock, flags); + if (hsuc->desc && hsuc->desc->status == DMA_IN_PROGRESS) { + hsu_dma_chan_deactivate(hsuc); + hsuc->desc->status = DMA_PAUSED; + } + spin_unlock_irqrestore(&hsuc->vchan.lock, flags); + + return 0; +} + +static int hsu_dma_resume(struct dma_chan *chan) +{ + struct hsu_dma_chan *hsuc = to_hsu_dma_chan(chan); + unsigned long flags; + + spin_lock_irqsave(&hsuc->vchan.lock, flags); + if (hsuc->desc && hsuc->desc->status == DMA_PAUSED) { + hsuc->desc->status = DMA_IN_PROGRESS; + hsu_dma_chan_activate(hsuc); + } + spin_unlock_irqrestore(&hsuc->vchan.lock, flags); + + return 0; +} + +static int hsu_dma_terminate_all(struct dma_chan *chan) +{ + struct hsu_dma_chan *hsuc = to_hsu_dma_chan(chan); + unsigned long flags; + LIST_HEAD(head); + + spin_lock_irqsave(&hsuc->vchan.lock, flags); + + hsu_dma_stop_channel(hsuc); + hsuc->desc = NULL; + + vchan_get_all_descriptors(&hsuc->vchan, &head); + spin_unlock_irqrestore(&hsuc->vchan.lock, flags); + vchan_dma_desc_free_list(&hsuc->vchan, &head); + + return 0; +} + +static int hsu_dma_alloc_chan_resources(struct dma_chan *chan) +{ + return 0; +} + +static void hsu_dma_free_chan_resources(struct dma_chan *chan) +{ + vchan_free_chan_resources(to_virt_chan(chan)); +} + +int hsu_dma_probe(struct hsu_dma_chip *chip) +{ + struct hsu_dma *hsu; + struct hsu_dma_platform_data *pdata = chip->pdata; + void __iomem *addr = chip->regs + chip->offset; + unsigned short i; + int ret; + + hsu = devm_kzalloc(chip->dev, sizeof(*hsu), GFP_KERNEL); + if (!hsu) + return -ENOMEM; + + chip->hsu = hsu; + + if (!pdata) { + pdata = devm_kzalloc(chip->dev, sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return -ENOMEM; + + chip->pdata = pdata; + + /* Guess nr_channels from the IO space length */ + pdata->nr_channels = (chip->length - chip->offset) / + HSU_DMA_CHAN_LENGTH; + } + + hsu->chan = devm_kcalloc(chip->dev, pdata->nr_channels, + sizeof(*hsu->chan), GFP_KERNEL); + if (!hsu->chan) + return -ENOMEM; + + INIT_LIST_HEAD(&hsu->dma.channels); + for (i = 0; i < pdata->nr_channels; i++) { + struct hsu_dma_chan *hsuc = &hsu->chan[i]; + + hsuc->vchan.desc_free = hsu_dma_desc_free; + vchan_init(&hsuc->vchan, &hsu->dma); + + hsuc->direction = (i & 0x1) ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV; + hsuc->reg = addr + i * HSU_DMA_CHAN_LENGTH; + + spin_lock_init(&hsuc->lock); + } + + dma_cap_set(DMA_SLAVE, hsu->dma.cap_mask); + dma_cap_set(DMA_PRIVATE, hsu->dma.cap_mask); + + hsu->dma.device_alloc_chan_resources = hsu_dma_alloc_chan_resources; + hsu->dma.device_free_chan_resources = hsu_dma_free_chan_resources; + + hsu->dma.device_prep_slave_sg = hsu_dma_prep_slave_sg; + + hsu->dma.device_issue_pending = hsu_dma_issue_pending; + hsu->dma.device_tx_status = hsu_dma_tx_status; + + hsu->dma.device_config = hsu_dma_slave_config; + hsu->dma.device_pause = hsu_dma_pause; + hsu->dma.device_resume = hsu_dma_resume; + hsu->dma.device_terminate_all = hsu_dma_terminate_all; + + hsu->dma.src_addr_widths = HSU_DMA_BUSWIDTHS; + hsu->dma.dst_addr_widths = HSU_DMA_BUSWIDTHS; + hsu->dma.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); + hsu->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; + + hsu->dma.dev = chip->dev; + + ret = dma_async_device_register(&hsu->dma); + if (ret) + return ret; + + dev_info(chip->dev, "Found HSU DMA, %d channels\n", pdata->nr_channels); + return 0; +} +EXPORT_SYMBOL_GPL(hsu_dma_probe); + +int hsu_dma_remove(struct hsu_dma_chip *chip) +{ + struct hsu_dma *hsu = chip->hsu; + unsigned short i; + + dma_async_device_unregister(&hsu->dma); + + for (i = 0; i < chip->pdata->nr_channels; i++) { + struct hsu_dma_chan *hsuc = &hsu->chan[i]; + + tasklet_kill(&hsuc->vchan.task); + } + + return 0; +} +EXPORT_SYMBOL_GPL(hsu_dma_remove); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("High Speed UART DMA core driver"); +MODULE_AUTHOR("Andy Shevchenko "); diff --git a/drivers/dma/hsu/hsu.h b/drivers/dma/hsu/hsu.h new file mode 100644 index 0000000000000..0275233cf550e --- /dev/null +++ b/drivers/dma/hsu/hsu.h @@ -0,0 +1,118 @@ +/* + * Driver for the High Speed UART DMA + * + * Copyright (C) 2015 Intel Corporation + * + * 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. + */ + +#ifndef __DMA_HSU_H__ +#define __DMA_HSU_H__ + +#include +#include + +#include "../virt-dma.h" + +#define HSU_CH_SR 0x00 /* channel status */ +#define HSU_CH_CR 0x04 /* channel control */ +#define HSU_CH_DCR 0x08 /* descriptor control */ +#define HSU_CH_BSR 0x10 /* FIFO buffer size */ +#define HSU_CH_MTSR 0x14 /* minimum transfer size */ +#define HSU_CH_DxSAR(x) (0x20 + 8 * (x)) /* desc start addr */ +#define HSU_CH_DxTSR(x) (0x24 + 8 * (x)) /* desc transfer size */ +#define HSU_CH_D0SAR 0x20 /* desc 0 start addr */ +#define HSU_CH_D0TSR 0x24 /* desc 0 transfer size */ +#define HSU_CH_D1SAR 0x28 +#define HSU_CH_D1TSR 0x2c +#define HSU_CH_D2SAR 0x30 +#define HSU_CH_D2TSR 0x34 +#define HSU_CH_D3SAR 0x38 +#define HSU_CH_D3TSR 0x3c + +#define HSU_DMA_CHAN_NR_DESC 4 +#define HSU_DMA_CHAN_LENGTH 0x40 + +/* Bits in HSU_CH_SR */ +#define HSU_CH_SR_DESCTO(x) BIT(8 + (x)) +#define HSU_CH_SR_DESCTO_ANY (BIT(11) | BIT(10) | BIT(9) | BIT(8)) +#define HSU_CH_SR_CHE BIT(15) + +/* Bits in HSU_CH_CR */ +#define HSU_CH_CR_CHA BIT(0) +#define HSU_CH_CR_CHD BIT(1) + +/* Bits in HSU_CH_DCR */ +#define HSU_CH_DCR_DESCA(x) BIT(0 + (x)) +#define HSU_CH_DCR_CHSOD(x) BIT(8 + (x)) +#define HSU_CH_DCR_CHSOTO BIT(14) +#define HSU_CH_DCR_CHSOE BIT(15) +#define HSU_CH_DCR_CHDI(x) BIT(16 + (x)) +#define HSU_CH_DCR_CHEI BIT(23) +#define HSU_CH_DCR_CHTOI(x) BIT(24 + (x)) + +struct hsu_dma_sg { + dma_addr_t addr; + unsigned int len; +}; + +struct hsu_dma_desc { + struct virt_dma_desc vdesc; + enum dma_transfer_direction direction; + struct hsu_dma_sg *sg; + unsigned int nents; + unsigned int active; + enum dma_status status; +}; + +static inline struct hsu_dma_desc *to_hsu_dma_desc(struct virt_dma_desc *vdesc) +{ + return container_of(vdesc, struct hsu_dma_desc, vdesc); +} + +struct hsu_dma_chan { + struct virt_dma_chan vchan; + + void __iomem *reg; + spinlock_t lock; + + /* hardware configuration */ + enum dma_transfer_direction direction; + struct dma_slave_config config; + + struct hsu_dma_desc *desc; +}; + +static inline struct hsu_dma_chan *to_hsu_dma_chan(struct dma_chan *chan) +{ + return container_of(chan, struct hsu_dma_chan, vchan.chan); +} + +static inline u32 hsu_chan_readl(struct hsu_dma_chan *hsuc, int offset) +{ + return readl(hsuc->reg + offset); +} + +static inline void hsu_chan_writel(struct hsu_dma_chan *hsuc, int offset, + u32 value) +{ + writel(value, hsuc->reg + offset); +} + +struct hsu_dma { + struct dma_device dma; + + /* channels */ + struct hsu_dma_chan *chan; +}; + +static inline struct hsu_dma *to_hsu_dma(struct dma_device *ddev) +{ + return container_of(ddev, struct hsu_dma, dma); +} + +#endif /* __DMA_HSU_H__ */ diff --git a/drivers/dma/hsu/pci.c b/drivers/dma/hsu/pci.c new file mode 100644 index 0000000000000..563b4685d7667 --- /dev/null +++ b/drivers/dma/hsu/pci.c @@ -0,0 +1,123 @@ +/* + * PCI driver for the High Speed UART DMA + * + * Copyright (C) 2015 Intel Corporation + * Author: Andy Shevchenko + * + * 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 +#include +#include +#include + +#include "hsu.h" + +#define HSU_PCI_DMASR 0x00 +#define HSU_PCI_DMAISR 0x04 + +#define HSU_PCI_CHAN_OFFSET 0x100 + +static irqreturn_t hsu_pci_irq(int irq, void *dev) +{ + struct hsu_dma_chip *chip = dev; + u32 dmaisr; + unsigned short i; + irqreturn_t ret = IRQ_NONE; + + dmaisr = readl(chip->regs + HSU_PCI_DMAISR); + for (i = 0; i < chip->pdata->nr_channels; i++) { + if (dmaisr & 0x1) + ret |= hsu_dma_irq(chip, i); + dmaisr >>= 1; + } + + return 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; + + 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 = pdev->irq; + + pci_enable_msi(pdev); + + 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; + + 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, 0x081e), 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 "); diff --git a/include/linux/dma/hsu.h b/include/linux/dma/hsu.h new file mode 100644 index 0000000000000..234393a6997bb --- /dev/null +++ b/include/linux/dma/hsu.h @@ -0,0 +1,48 @@ +/* + * Driver for the High Speed UART DMA + * + * Copyright (C) 2015 Intel Corporation + * + * 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. + */ + +#ifndef _DMA_HSU_H +#define _DMA_HSU_H + +#include +#include + +#include + +struct hsu_dma; + +/** + * struct hsu_dma_chip - representation of HSU DMA hardware + * @dev: struct device of the DMA controller + * @irq: irq line + * @regs: memory mapped I/O space + * @length: I/O space length + * @offset: offset of the I/O space where registers are located + * @hsu: struct hsu_dma that is filed by ->probe() + * @pdata: platform data for the DMA controller if provided + */ +struct hsu_dma_chip { + struct device *dev; + int irq; + void __iomem *regs; + unsigned int length; + unsigned int offset; + struct hsu_dma *hsu; + struct hsu_dma_platform_data *pdata; +}; + +/* Export to the internal users */ +irqreturn_t hsu_dma_irq(struct hsu_dma_chip *chip, unsigned short nr); + +/* Export to the platform drivers */ +int hsu_dma_probe(struct hsu_dma_chip *chip); +int hsu_dma_remove(struct hsu_dma_chip *chip); + +#endif /* _DMA_HSU_H */ diff --git a/include/linux/platform_data/dma-hsu.h b/include/linux/platform_data/dma-hsu.h new file mode 100644 index 0000000000000..8a1f6a4920b2e --- /dev/null +++ b/include/linux/platform_data/dma-hsu.h @@ -0,0 +1,25 @@ +/* + * Driver for the High Speed UART DMA + * + * Copyright (C) 2015 Intel Corporation + * + * 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. + */ + +#ifndef _PLATFORM_DATA_DMA_HSU_H +#define _PLATFORM_DATA_DMA_HSU_H + +#include + +struct hsu_dma_slave { + struct device *dma_dev; + int chan_id; +}; + +struct hsu_dma_platform_data { + unsigned short nr_channels; +}; + +#endif /* _PLATFORM_DATA_DMA_HSU_H */