This patch adds a driver for NBPF DMAC IP cores from Renesas, designed for
the AMBA AXI bus.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@xxxxxxxxx>
---
v2:
1. corrected copyright and a Renesas email for proper attribution
2. use %pad for dma_addr_t
3. use devm_request_irq() instead of the threaded version
4. replaces pr_debug() with dev_dbg()
5. more precise types for variables, used directly with the hardware
6. call of_dma_controller_register() after dma_async_device_register()
7. cosmetic: improved comments and simplified a loop
Thanks to all for comments
Documentation/devicetree/bindings/dma/nbpfaxi.txt | 61 +
drivers/dma/Kconfig | 6 +
drivers/dma/Makefile | 1 +
drivers/dma/nbpfaxi.c | 1551 +++++++++++++++++++++
include/dt-bindings/dma/nbpfaxi.h | 20 +
5 files changed, 1639 insertions(+)
create mode 100644 Documentation/devicetree/bindings/dma/nbpfaxi.txt
create mode 100644 drivers/dma/nbpfaxi.c
create mode 100644 include/dt-bindings/dma/nbpfaxi.h
diff --git a/Documentation/devicetree/bindings/dma/nbpfaxi.txt b/Documentation/devicetree/bindings/dma/nbpfaxi.txt
new file mode 100644
index 0000000..d5e2522
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/nbpfaxi.txt
@@ -0,0 +1,61 @@
+* Renesas "Type-AXI" NBPFAXI* DMA controllers
+
+* DMA controller
+
+Required properties
+
+- compatible: must be one of
+ "renesas,nbpfaxi64dmac1b4"
+ "renesas,nbpfaxi64dmac1b8"
+ "renesas,nbpfaxi64dmac1b16"
+ "renesas,nbpfaxi64dmac4b4"
+ "renesas,nbpfaxi64dmac4b8"
+ "renesas,nbpfaxi64dmac4b16"
+ "renesas,nbpfaxi64dmac8b4"
+ "renesas,nbpfaxi64dmac8b8"
+ "renesas,nbpfaxi64dmac8b16"
+- #dma-cells: must be 2: the first integer is a terminal number, to which this
+ slave is connected, the second one is flags. Flags is a bitmask
+ with the following bits defined:
+
+#define NBPF_SLAVE_RQ_HIGH 1
+#define NBPF_SLAVE_RQ_LOW 2
+#define NBPF_SLAVE_RQ_LEVEL 4
+
+Optional properties:
+
+You can use dma-channels and dma-requests as described in dma.txt, although they
+won't be used, this information is derived from the compatibility string.
+
+Example:
+
+ dma: dma-controller@48000000 {
+ compatible = "renesas,nbpfaxi64dmac8b4";
+ reg = <0x48000000 0x400>;
+ interrupts = <0 12 0x4
+ 0 13 0x4
+ 0 14 0x4
+ 0 15 0x4
+ 0 16 0x4
+ 0 17 0x4
+ 0 18 0x4
+ 0 19 0x4>;
+ #dma-cells = <2>;
+ dma-channels = <8>;
+ dma-requests = <8>;
+ };
+
+* DMA client
+
+Required properties:
+
+dmas and dma-names are required, as described in dma.txt.
+
+Example:
+
+#include <dt-bindings/dma/nbpfaxi.h>
+
+...
+ dmas = <&dma 0 (NBPF_SLAVE_RQ_HIGH | NBPF_SLAVE_RQ_LEVEL)
+ &dma 1 (NBPF_SLAVE_RQ_HIGH | NBPF_SLAVE_RQ_LEVEL)>;
+ dma-names = "rx", "tx";
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index ba06d1d..513207a 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -361,6 +361,12 @@ config FSL_EDMA
multiplexing capability for DMA request sources(slot).
This module can be found on Freescale Vybrid and LS-1 SoCs.
+config NBPFAXI_DMA
+ tristate "Renesas Type-AXI NBPF DMA support"
+ select DMA_ENGINE
+ help
+ Support for "Type-AXI" NBPF DMA IPs from Renesas
+
config DMA_ENGINE
bool
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 5150c82..9589ebb 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -46,3 +46,4 @@ obj-$(CONFIG_K3_DMA) += k3dma.o
obj-$(CONFIG_MOXART_DMA) += moxart-dma.o
obj-$(CONFIG_FSL_EDMA) += fsl-edma.o
obj-$(CONFIG_QCOM_BAM_DMA) += qcom_bam_dma.o
+obj-$(CONFIG_NBPFAXI_DMA) += nbpfaxi.o
diff --git a/drivers/dma/nbpfaxi.c b/drivers/dma/nbpfaxi.c
new file mode 100644
index 0000000..b0d6676
--- /dev/null
+++ b/drivers/dma/nbpfaxi.c
@@ -0,0 +1,1551 @@
+/*
+ * Copyright (C) 2013-2014 Renesas Electronics Europe Ltd.
+ * Author: Guennadi Liakhovetski <g.liakhovetski@xxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/log2.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_dma.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <dt-bindings/dma/nbpfaxi.h>
+
+#include "dmaengine.h"
+
+#define NBPF_REG_CHAN_OFFSET 0
+#define NBPF_REG_CHAN_SIZE 0x40
+
+/* Channel Current Transaction Byte register */
+#define NBPF_CHAN_CUR_TR_BYTE 0x20
+
+/* Channel Status register */
+#define NBPF_CHAN_STAT 0x24
+#define NBPF_CHAN_STAT_EN 1
+#define NBPF_CHAN_STAT_TACT 4
+#define NBPF_CHAN_STAT_ERR 0x10
+#define NBPF_CHAN_STAT_END 0x20
+#define NBPF_CHAN_STAT_TC 0x40
+#define NBPF_CHAN_STAT_DER 0x400
+
+/* Channel Control register */
+#define NBPF_CHAN_CTRL 0x28
+#define NBPF_CHAN_CTRL_SETEN 1
+#define NBPF_CHAN_CTRL_CLREN 2
+#define NBPF_CHAN_CTRL_STG 4
+#define NBPF_CHAN_CTRL_SWRST 8
+#define NBPF_CHAN_CTRL_CLRRQ 0x10
+#define NBPF_CHAN_CTRL_CLREND 0x20
+#define NBPF_CHAN_CTRL_CLRTC 0x40
+#define NBPF_CHAN_CTRL_SETSUS 0x100
+#define NBPF_CHAN_CTRL_CLRSUS 0x200
+
+/* Channel Configuration register */
+#define NBPF_CHAN_CFG 0x2c
+#define NBPF_CHAN_CFG_SEL 7 /* terminal SELect: 0..7 */
+#define NBPF_CHAN_CFG_REQD 8 /* REQuest Direction: DMAREQ is 0: input, 1: output */
+#define NBPF_CHAN_CFG_LOEN 0x10 /* LOw ENable: low DMA request line is: 0: inactive, 1: active */
+#define NBPF_CHAN_CFG_HIEN 0x20 /* HIgh ENable: high DMA request line is: 0: inactive, 1: active */
+#define NBPF_CHAN_CFG_LVL 0x40 /* LeVeL: DMA request line is sensed as 0: edge, 1: level */
+#define NBPF_CHAN_CFG_AM 0x700 /* ACK Mode: 0: Pulse mode, 1: Level mode, b'1x: Bus Cycle */
+#define NBPF_CHAN_CFG_SDS 0xf000 /* Source Data Size: 0: 8 bits,... , 7: 1024 bits */
+#define NBPF_CHAN_CFG_DDS 0xf0000 /* Destination Data Size: as above */
+#define NBPF_CHAN_CFG_SAD 0x100000 /* Source ADdress counting: 0: increment, 1: fixed */
+#define NBPF_CHAN_CFG_DAD 0x200000 /* Destination ADdress counting: 0: increment, 1: fixed */
+#define NBPF_CHAN_CFG_TM 0x400000 /* Transfer Mode: 0: single, 1: block TM */
+#define NBPF_CHAN_CFG_DEM 0x1000000 /* DMAEND interrupt Mask */
+#define NBPF_CHAN_CFG_TCM 0x2000000 /* DMATCO interrupt Mask */
+#define NBPF_CHAN_CFG_SBE 0x8000000 /* Sweep Buffer Enable */
+#define NBPF_CHAN_CFG_RSEL 0x10000000 /* RM: Register Set sELect */
+#define NBPF_CHAN_CFG_RSW 0x20000000 /* RM: Register Select sWitch */
+#define NBPF_CHAN_CFG_REN 0x40000000 /* RM: Register Set Enable */
+#define NBPF_CHAN_CFG_DMS 0x80000000 /* 0: register mode (RM), 1: link mode (LM) */
+
+#define NBPF_CHAN_NXLA 0x38
+#define NBPF_CHAN_CRLA 0x3c
+
+/* Link Header field */
+#define NBPF_HEADER_LV 1
+#define NBPF_HEADER_LE 2
+#define NBPF_HEADER_WBD 4
+#define NBPF_HEADER_DIM 8
+
+#define NBPF_CTRL 0x300
+#define NBPF_CTRL_PR 1 /* 0: fixed priority, 1: round robin */
+#define NBPF_CTRL_LVINT 2 /* DMAEND and DMAERR signalling: 0: pulse, 1: level */
+
+#define NBPF_DSTAT_ER 0x314
+#define NBPF_DSTAT_END 0x318
+
+#define NBPF_DMA_BUSWIDTHS \
+ (BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) | \
+ BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
+ BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
+ BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \
+ BIT(DMA_SLAVE_BUSWIDTH_8_BYTES))
+
+struct nbpf_config {
+ int num_channels;
+ int buffer_size;
+};
+
+/*
+ * We've got 3 types of objects, used to describe DMA transfers:
+ * 1. high-level descriptor, containing a struct dma_async_tx_descriptor object
+ * in it, used to communicate with the user
+ * 2. hardware DMA link descriptors, that we pass to DMAC for DMA transfer
+ * queuing, these must be DMAable, using either the streaming DMA API or
+ * allocated from coherent memory - one per SG segment
+ * 3. one per SG segment descriptors, used to manage HW link descriptors from
+ * (2). They do not have to be DMAable. They can either be (a) allocated
+ * together with link descriptors as mixed (DMA / CPU) objects, or (b)
+ * separately. Even if allocated separately it would be best to link them
+ * to link descriptors once during channel resource allocation and always
+ * use them as a single object.
+ * Therefore for both cases (a) and (b) at run-time objects (2) and (3) shall be
+ * treated as a single SG segment descriptor.
+ */
+
+struct nbpf_link_reg {
+ u32 header;
+ u32 src_addr;
+ u32 dst_addr;
+ u32 transaction_size;
+ u32 config;
+ u32 interval;
+ u32 extension;
+ u32 next;
+} __packed;
+
+struct nbpf_device;
+struct nbpf_channel;
+struct nbpf_desc;
+
+struct nbpf_link_desc {
+ struct nbpf_link_reg *hwdesc;
+ dma_addr_t hwdesc_dma_addr;
+ struct nbpf_desc *desc;
+ struct list_head node;
+};
+
+/**
+ * @sg: list of hardware descriptors, represented by struct nbpf_link_desc
+ * @node: member in channel descriptor lists
+ */
+struct nbpf_desc {
+ struct dma_async_tx_descriptor async_tx;
+ bool user_wait;
+ struct nbpf_channel *chan;
+ struct list_head sg;
+ struct list_head node;
+};
+
+/* Take a wild guess: allocate 4 segments per descriptor */
+#define NBPF_SEGMENTS_PER_DESC 4
+#define NBPF_DESCS_PER_PAGE ((PAGE_SIZE - sizeof(struct list_head)) / \
+ (sizeof(struct nbpf_desc) + \
+ NBPF_SEGMENTS_PER_DESC * \
+ (sizeof(struct nbpf_link_desc) + sizeof(struct nbpf_link_reg))))
+#define NBPF_SEGMENTS_PER_PAGE (NBPF_SEGMENTS_PER_DESC * NBPF_DESCS_PER_PAGE)
+
+struct nbpf_desc_page {
+ struct list_head node;
+ struct nbpf_desc desc[NBPF_DESCS_PER_PAGE];
+ struct nbpf_link_desc ldesc[NBPF_SEGMENTS_PER_PAGE];
+ struct nbpf_link_reg hwdesc[NBPF_SEGMENTS_PER_PAGE];
+};
+
+#define NBPF_STATUS_SHIFT 7
+#define NBPF_STATUS_KEEP BIT(NBPF_STATUS_SHIFT)
+#define NBPF_STATUS_MASK (NBPF_STATUS_KEEP - 1)
+
+/**
+ * struct nbpf_channel - one DMAC channel
+ * @dma_chan: standard dmaengine channel object
+ * @base: register address base
+ * @nbpf: DMAC
+ * @name: IRQ name
+ * @irq: IRQ number
+ * @slave_addr: address for slave DMA
+ * @slave_width:slave data size in bytes
+ * @slave_burst:maximum slave burst size in bytes
+ * @terminal: DMA terminal, assigned to this channel
+ * @dmarq_cfg: DMA request line configuration - high / low, edge / level for NBPF_CHAN_CFG
+ * @flags: configuration flags from DT
+ * @lock: protect descriptor lists
+ * @free_links: list of free link descriptors
+ * @free: list of free descriptors
+ * @queued: list of queued descriptors
+ * @active: list of descriptors, scheduled for processing
+ * @done: list of completed descriptors, waiting post-processing
+ * @desc_page: list of additionally allocated descriptor pages - if any
+ */
+struct nbpf_channel {
+ struct dma_chan dma_chan;
+ void __iomem *base;
+ struct nbpf_device *nbpf;
+ char name[16];
+ int irq;
+ dma_addr_t slave_addr;
+ size_t slave_width;
+ size_t slave_burst;
+ unsigned int terminal;
+ u32 dmarq_cfg;
+ unsigned long flags;
+ spinlock_t lock;
+ struct list_head free_links;
+ struct list_head free;
+ struct list_head queued;
+ struct list_head active;
+ struct list_head done;
+ struct list_head desc_page;
+ struct nbpf_desc *running;
+ dma_cookie_t cookie_forgotten;
+ DECLARE_BITMAP(status, NBPF_STATUS_KEEP);
+ bool paused;
+};
+
+struct nbpf_device {
+ struct dma_device dma_dev;
+ void __iomem *base;
+ struct clk *clk;
+ const struct nbpf_config *config;
+ struct nbpf_channel chan[];
+};
+
+enum nbpf_model {
+ NBPF1B4,
+ NBPF1B8,
+ NBPF1B16,
+ NBPF4B4,
+ NBPF4B8,
+ NBPF4B16,
+ NBPF8B4,
+ NBPF8B8,
+ NBPF8B16,
+};
+
+static struct nbpf_config nbpf_cfg[] = {
+ [NBPF1B4] = {
+ .num_channels = 1,
+ .buffer_size = 4,
+ },
+ [NBPF1B8] = {
+ .num_channels = 1,
+ .buffer_size = 8,
+ },
+ [NBPF1B16] = {
+ .num_channels = 1,
+ .buffer_size = 16,
+ },
+ [NBPF4B4] = {
+ .num_channels = 4,
+ .buffer_size = 4,
+ },
+ [NBPF4B8] = {
+ .num_channels = 4,
+ .buffer_size = 8,
+ },
+ [NBPF4B16] = {
+ .num_channels = 4,
+ .buffer_size = 16,
+ },
+ [NBPF8B4] = {
+ .num_channels = 8,
+ .buffer_size = 4,
+ },
+ [NBPF8B8] = {
+ .num_channels = 8,
+ .buffer_size = 8,
+ },
+ [NBPF8B16] = {
+ .num_channels = 8,
+ .buffer_size = 16,
+ },
+};
+
+#define nbpf_to_chan(d) container_of(d, struct nbpf_channel, dma_chan)
+
+/*
+ * dmaengine drivers seem to have a lot in common and instead of sharing more
+ * code, they reimplement those common algorithms independently. In this driver
+ * we try to separate the hardware-specific part from the (largely) generic
+ * part. This improves code readability and makes it possible in the future to
+ * reuse the generic code in form of a helper library. That generic code should
+ * be suitable for various DMA controllers, using transfer descriptors in RAM
+ * and pushing one SG list at a time to the DMA controller.
+ */
+
+/* Hardware-specific part */
+
+static inline u32 nbpf_chan_read(struct nbpf_channel *chan,
+ unsigned int offset)
+{
+ u32 data = ioread32(chan->base + offset);
+ dev_dbg(chan->dma_chan.device->dev, "%s(0x%p + 0x%x) = 0x%x\n",
+ __func__, chan->base, offset, data);
+ return data;
+}
+
+static inline void nbpf_chan_write(struct nbpf_channel *chan,
+ unsigned int offset, u32 data)
+{
+ iowrite32(data, chan->base + offset);
+ dev_dbg(chan->dma_chan.device->dev, "%s(0x%p + 0x%x) = 0x%x\n",
+ __func__, chan->base, offset, data);
+}
+
+static inline u32 nbpf_read(struct nbpf_device *nbpf,
+ unsigned int offset)
+{
+ u32 data = ioread32(nbpf->base + offset);
+ dev_dbg(nbpf->dma_dev.dev, "%s(0x%p + 0x%x) = 0x%x\n",
+ __func__, nbpf->base, offset, data);
+ return data;
+}
+
+static inline void nbpf_write(struct nbpf_device *nbpf,
+ unsigned int offset, u32 data)
+{
+ iowrite32(data, nbpf->base + offset);
+ dev_dbg(nbpf->dma_dev.dev, "%s(0x%p + 0x%x) = 0x%x\n",
+ __func__, nbpf->base, offset, data);
+}
+
+static void nbpf_chan_halt(struct nbpf_channel *chan)
+{
+ nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_CLREN);
+}
+
+static bool nbpf_status_get(struct nbpf_channel *chan)
+{
+ u32 status = nbpf_read(chan->nbpf, NBPF_DSTAT_END);
+
+ return status & BIT(chan - chan->nbpf->chan);
+}
+
+static void nbpf_status_ack(struct nbpf_channel *chan)
+{
+ nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_CLREND);
+}
+
+static u32 nbpf_error_get(struct nbpf_device *nbpf)
+{
+ return nbpf_read(nbpf, NBPF_DSTAT_ER);
+}
+
+struct nbpf_channel *nbpf_error_get_channel(struct nbpf_device *nbpf, u32 error)
+{
+ return nbpf->chan + __ffs(error);
+}
+
+static void nbpf_error_clear(struct nbpf_channel *chan)
+{
+ u32 status;
+ int i;
+
+ /* Stop the channel, make sure DMA has been aborted */
+ nbpf_chan_halt(chan);
+
+ for (i = 1000; i; i--) {
+ status = nbpf_chan_read(chan, NBPF_CHAN_STAT);
+ if (!(status & NBPF_CHAN_STAT_TACT))
+ break;
+ cpu_relax();
+ }
+
+ if (!i)
+ dev_err(chan->dma_chan.device->dev,
+ "%s(): abort timeout, channel status 0x%x\n", __func__, status);
+
+ nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_SWRST);
+}
+
+static int nbpf_start(struct nbpf_desc *desc)
+{
+ struct nbpf_channel *chan = desc->chan;
+ struct nbpf_link_desc *ldesc = list_first_entry(&desc->sg, struct nbpf_link_desc, node);
+
+ nbpf_chan_write(chan, NBPF_CHAN_NXLA, (u32)ldesc->hwdesc_dma_addr);
+ nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_SETEN | NBPF_CHAN_CTRL_CLRSUS);
+ chan->paused = false;
+
+ /* Software trigger MEMCPY - only MEMCPY uses the block mode */
+ if (ldesc->hwdesc->config & NBPF_CHAN_CFG_TM)
+ nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_STG);
+
+ dev_dbg(chan->nbpf->dma_dev.dev, "%s(): next 0x%x, cur 0x%x\n", __func__,
+ nbpf_chan_read(chan, NBPF_CHAN_NXLA), nbpf_chan_read(chan, NBPF_CHAN_CRLA));
+
+ return 0;
+}
+
+static void nbpf_chan_prepare(struct nbpf_channel *chan)
+{
+ chan->dmarq_cfg = (chan->flags & NBPF_SLAVE_RQ_HIGH ? NBPF_CHAN_CFG_HIEN : 0) |
+ (chan->flags & NBPF_SLAVE_RQ_LOW ? NBPF_CHAN_CFG_LOEN : 0) |
+ (chan->flags & NBPF_SLAVE_RQ_LEVEL ?
+ NBPF_CHAN_CFG_LVL | (NBPF_CHAN_CFG_AM & 0x200) : 0) |
+ chan->terminal;
+}
+
+static void nbpf_chan_prepare_default(struct nbpf_channel *chan)
+{
+ /* Don't output DMAACK */
+ chan->dmarq_cfg = NBPF_CHAN_CFG_AM & 0x400;
+ chan->terminal = 0;
+ chan->flags = 0;
+}
+
+static void nbpf_chan_configure(struct nbpf_channel *chan)
+{
+ /*
+ * We assume, that only the link mode and DMA request line configuration
+ * have to be set in the configuration register manually. Dynamic
+ * per-transfer configuration will be loaded from transfer descriptors.
+ */
+ nbpf_chan_write(chan, NBPF_CHAN_CFG, NBPF_CHAN_CFG_DMS | chan->dmarq_cfg);
+}
+
+static u32 nbpf_xfer_ds(struct nbpf_device *nbpf, size_t size)
+{
+ /* Maximum supported bursts depend on the buffer size */
+ return min_t(int, __ffs(size), ilog2(nbpf->config->buffer_size * 8));
+}
+
+static size_t nbpf_xfer_size(struct nbpf_device *nbpf,
+ enum dma_slave_buswidth width, u32 burst)
+{
+ size_t size;
+
+ if (!burst)
+ burst = 1;
+
+ switch (width) {
+ case DMA_SLAVE_BUSWIDTH_8_BYTES:
+ size = 8 * burst;
+ break;
+ case DMA_SLAVE_BUSWIDTH_4_BYTES:
+ size = 4 * burst;
+ break;
+ case DMA_SLAVE_BUSWIDTH_2_BYTES:
+ size = 2 * burst;
+ break;
+ default:
+ pr_warn("%s(): invalid bus width %u\n", __func__, width);
+ case DMA_SLAVE_BUSWIDTH_1_BYTE:
+ size = burst;
+ }
+
+ return nbpf_xfer_ds(nbpf, size);
+}
+
+/*
+ * We need a way to recognise slaves, whose data is sent "raw" over the bus,
+ * i.e. it isn't known in advance how many bytes will be received. Therefore
+ * the slave driver has to provide a "large enough" buffer and either read the
+ * buffer, when it is full, or detect, that some data has arrived, then wait for
+ * a timeout, if no more data arrives - receive what's already there. We want to
+ * handle such slaves in a special way to allow an optimised mode for other
+ * users, for whom the amount of data is known in advance. So far there's no way
+ * to recognise such slaves. We use a data-width check to distinguish between
+ * the SD host and the PL011 UART.
+ */
+#define nbpf_slave_can_burst(chan) (chan->slave_width >= 3)
+
+static int nbpf_prep_one(struct nbpf_link_desc *ldesc,
+ enum dma_transfer_direction direction,
+ dma_addr_t src, dma_addr_t dst, size_t size, bool last)
+{
+ struct nbpf_link_reg *hwdesc = ldesc->hwdesc;
+ struct nbpf_desc *desc = ldesc->desc;
+ struct nbpf_channel *chan = desc->chan;
+ struct device *dev = chan->dma_chan.device->dev;
+ size_t mem_xfer, slave_xfer;
+
+ hwdesc->header = NBPF_HEADER_WBD | NBPF_HEADER_LV |
+ (last ? NBPF_HEADER_LE : 0);
+
+ hwdesc->src_addr = src;
+ hwdesc->dst_addr = dst;
+ hwdesc->transaction_size = size;
+
+ /*
+ * set config: SAD, DAD, DDS, SDS, etc.
+ * Note on transfer sizes: the DMAC can perform unaligned DMA transfers,
+ * but it is important to have transaction size a multiple of both
+ * receiver and transmitter transfer sizes. It is also possible to use
+ * different RAM and device transfer sizes, and it does work well with
+ * some devices, e.g. with V08R07S01E SD host controllers, which can use
+ * 128 byte transfers. But this doesn't work with other devices,
+ * especially when the transaction size is unknown. This is the case,
+ * e.g. with serial drivers like amba-pl011.c. For reception it sets up
+ * the transaction size of 4K and if fewer bytes are received, it
+ * pauses DMA and reads out data received via DMA as well as those left
+ * in the Rx FIFO. For this to work with the RAM side using burst
+ * transfers we enable the SBE bit and terminate the transfer in our
+ * DMA_PAUSE handler.
+ */
+ mem_xfer = nbpf_xfer_ds(chan->nbpf, size);
+ slave_xfer = min(mem_xfer, nbpf_slave_can_burst(chan) ?
+ chan->slave_burst : chan->slave_width);
+
+ switch (direction) {
+ case DMA_DEV_TO_MEM:
+ /*
+ * Is the slave narrower than 64 bits, i.e. isn't using the full
+ * bus width and cannot use bursts?
+ */
+ if (mem_xfer > chan->slave_burst && !nbpf_slave_can_burst(chan))
+ mem_xfer = chan->slave_burst;
+ /* Device-to-RAM DMA is unreliable without REQD set */
+ hwdesc->config = NBPF_CHAN_CFG_SAD | (NBPF_CHAN_CFG_DDS & (mem_xfer << 16)) |
+ (NBPF_CHAN_CFG_SDS & (slave_xfer << 12)) | NBPF_CHAN_CFG_REQD |
+ NBPF_CHAN_CFG_SBE;
+ break;
+ case DMA_MEM_TO_DEV:
+ hwdesc->config = NBPF_CHAN_CFG_DAD | (NBPF_CHAN_CFG_SDS & (mem_xfer << 12)) |
+ (NBPF_CHAN_CFG_DDS & (slave_xfer << 16)) | NBPF_CHAN_CFG_REQD;
+ break;
+ case DMA_MEM_TO_MEM:
+ hwdesc->config = NBPF_CHAN_CFG_TCM | NBPF_CHAN_CFG_TM |
+ (NBPF_CHAN_CFG_SDS & (mem_xfer << 12)) |
+ (NBPF_CHAN_CFG_DDS & (mem_xfer << 16));
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ hwdesc->config |= chan->dmarq_cfg | (last ? 0 : NBPF_CHAN_CFG_DEM) |
+ NBPF_CHAN_CFG_DMS;
+
+ dev_dbg(dev, "%s(): desc @ %pad: hdr 0x%x, cfg 0x%x, %u @ %pad -> %pad\n",
+ __func__, &ldesc->hwdesc_dma_addr, hwdesc->header,
+ hwdesc->config, size, &src, &dst);
+
+ dma_sync_single_for_device(dev, ldesc->hwdesc_dma_addr, sizeof(*hwdesc),
+ DMA_TO_DEVICE);
+
+ return 0;
+}
+
+static size_t nbpf_bytes_left(struct nbpf_channel *chan)
+{
+ return nbpf_chan_read(chan, NBPF_CHAN_CUR_TR_BYTE);
+}
+
+static void nbpf_configure(struct nbpf_device *nbpf)
+{
+ nbpf_write(nbpf, NBPF_CTRL, NBPF_CTRL_LVINT);
+}
+
+static void nbpf_pause(struct nbpf_channel *chan)
+{
+ nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_SETSUS);
+ /* See comment in nbpf_prep_one() */
+ nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_CLREN);
+}
+
+/* Generic part */
+
+/* DMA ENGINE functions */
+static void nbpf_issue_pending(struct dma_chan *dchan)
+{
+ struct nbpf_channel *chan = nbpf_to_chan(dchan);
+ unsigned long flags;
+
+ dev_dbg(dchan->device->dev, "Entry %s()\n", __func__);
+
+ spin_lock_irqsave(&chan->lock, flags);
+ if (list_empty(&chan->queued))
+ goto unlock;
+
+ list_splice_tail_init(&chan->queued, &chan->active);
+
+ if (!chan->running) {
+ struct nbpf_desc *desc = list_first_entry(&chan->active,
+ struct nbpf_desc, node);
+ if (!nbpf_start(desc))
+ chan->running = desc;
+ }
+
+unlock:
+ spin_unlock_irqrestore(&chan->lock, flags);
+}
+
+/*
+ * cookies are numbered 1...DMA_MAX_COOKIE=INT_MAX
+ */
+static void nbpf_cookie_update(struct nbpf_channel *chan, dma_cookie_t cookie)
+{
+ dma_cookie_t forgotten = cookie - NBPF_STATUS_KEEP;
+
+ if (cookie < NBPF_STATUS_KEEP && !chan->cookie_forgotten)
+ /* Not forgetting yet */
+ return;
+
+ if (forgotten < DMA_MIN_COOKIE)
+ /* Wrapped */
+ forgotten = (DMA_MAX_COOKIE & ~NBPF_STATUS_MASK) + cookie;
+ chan->cookie_forgotten = forgotten;
+}
+
+static bool nbpf_cookie_in_cache(struct nbpf_channel *chan,
+ dma_cookie_t cookie, struct dma_tx_state *state)
+{
+ if (cookie > chan->cookie_forgotten)
+ return true;
+
+ /*
+ * We still remember the cookie, if it has wrapped beyond INT_MAX:
+ * (1) forgotten is almost INT_MAX
+ * cookie_forgotten >> NBPF_STATUS_SHIFT == DMA_MAX_COOKIE >> NBPF_STATUS_SHIFT
+ * and enquired is small
+ * (2)
+ * cookie & ~NBPF_STATUS_MASK == 0
+ */
+
+ return chan->cookie_forgotten >> NBPF_STATUS_SHIFT ==
+ DMA_MAX_COOKIE >> NBPF_STATUS_SHIFT &&
+ !(cookie < ~NBPF_STATUS_MASK);
+}
+
+static void nbpf_cookie_success(struct nbpf_channel *chan, dma_cookie_t cookie)
+{
+ nbpf_cookie_update(chan, cookie);
+ clear_bit(cookie & NBPF_STATUS_MASK, chan->status);
+}
+
+static void nbpf_cookie_fail(struct nbpf_channel *chan, dma_cookie_t cookie)
+{
+ nbpf_cookie_update(chan, cookie);
+ set_bit(cookie & NBPF_STATUS_MASK, chan->status);
+}
+
+static enum dma_status nbpf_cookie_cached(struct nbpf_channel *chan,
+ dma_cookie_t cookie, struct dma_tx_state *state)
+{
+ return test_bit(cookie & NBPF_STATUS_MASK, chan->status) ?
+ DMA_ERROR : DMA_COMPLETE;
+}
+
+static enum dma_status nbpf_tx_status(struct dma_chan *dchan,
+ dma_cookie_t cookie, struct dma_tx_state *state)
+{
+ struct nbpf_channel *chan = nbpf_to_chan(dchan);
+ enum dma_status status = dma_cookie_status(dchan, cookie, state);
+ dma_cookie_t running = chan->running ? chan->running->async_tx.cookie : -EINVAL;
+
+ if (chan->paused)
+ status = DMA_PAUSED;
+
+ /* Note: we cannot return residues for old cookies */
+ if (state && cookie == running) {
+ state->residue = nbpf_bytes_left(chan);
+ dev_dbg(dchan->device->dev, "%s(): residue %u\n", __func__,
+ state->residue);
+ }
+
+ if (status == DMA_IN_PROGRESS || status == DMA_PAUSED)
+ return status;
+
+ if (nbpf_cookie_in_cache(chan, cookie, state))
+ return nbpf_cookie_cached(chan, cookie, state);
+
+ return status;
+}
+
+static dma_cookie_t nbpf_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+ struct nbpf_desc *desc = container_of(tx, struct nbpf_desc, async_tx);
+ struct nbpf_channel *chan = desc->chan;
+ unsigned long flags;
+ dma_cookie_t cookie;
+
+ spin_lock_irqsave(&chan->lock, flags);
+ cookie = dma_cookie_assign(tx);
+ list_add_tail(&desc->node, &chan->queued);
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ dev_dbg(chan->dma_chan.device->dev, "Entry %s(%d)\n", __func__, cookie);
+
+ return cookie;
+}
+
+static int nbpf_desc_page_alloc(struct nbpf_channel *chan)
+{
+ struct dma_chan *dchan = &chan->dma_chan;
+ struct nbpf_desc_page *dpage = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
+ struct nbpf_link_desc *ldesc;
+ struct nbpf_link_reg *hwdesc;
+ struct nbpf_desc *desc;
+ LIST_HEAD(head);
+ LIST_HEAD(lhead);
+ int i;
+ struct device *dev = dchan->device->dev;
+
+ if (!dpage)
+ return -ENOMEM;
+
+ dev_dbg(dev, "%s(): alloc %lu descriptors, %lu segments, total alloc %u\n",
+ __func__, NBPF_DESCS_PER_PAGE, NBPF_SEGMENTS_PER_PAGE, sizeof(*dpage));
+
+ for (i = 0, ldesc = dpage->ldesc, hwdesc = dpage->hwdesc;
+ i < ARRAY_SIZE(dpage->ldesc);
+ i++, ldesc++, hwdesc++) {
+ ldesc->hwdesc = hwdesc;
+ list_add_tail(&ldesc->node, &lhead);
+ ldesc->hwdesc_dma_addr = dma_map_single(dchan->device->dev,
+ hwdesc, sizeof(*hwdesc), DMA_TO_DEVICE);
+
+ dev_dbg(dev, "%s(): mapped 0x%p to %pad\n", __func__,
+ hwdesc, &ldesc->hwdesc_dma_addr);
+ }
+
+ for (i = 0, desc = dpage->desc;
+ i < ARRAY_SIZE(dpage->desc);
+ i++, desc++) {
+ dma_async_tx_descriptor_init(&desc->async_tx, dchan);
+ desc->async_tx.tx_submit = nbpf_tx_submit;
+ desc->chan = chan;
+ INIT_LIST_HEAD(&desc->sg);
+ list_add_tail(&desc->node, &head);
+ }
+
+ /*
+ * This function cannot be called from interrupt context, so, no need to
+ * save flags
+ */
+ spin_lock_irq(&chan->lock);
+ list_splice_tail(&lhead, &chan->free_links);
+ list_splice_tail(&head, &chan->free);
+ list_add(&dpage->node, &chan->desc_page);
+ spin_unlock_irq(&chan->lock);
+
+ return ARRAY_SIZE(dpage->desc);
+}
+
+static void nbpf_desc_put(struct nbpf_desc *desc)
+{
+ struct nbpf_channel *chan = desc->chan;
+ struct nbpf_link_desc *ldesc, *tmp;
+ unsigned long flags;
+
+ spin_lock_irqsave(&chan->lock, flags);
+ list_for_each_entry_safe(ldesc, tmp, &desc->sg, node)
+ list_move(&ldesc->node, &chan->free_links);
+
+ list_add(&desc->node, &chan->free);
+ spin_unlock_irqrestore(&chan->lock, flags);
+}
+
+static void nbpf_scan_acked(struct nbpf_channel *chan)
+{
+ struct nbpf_desc *desc, *tmp;
+ unsigned long flags;
+ LIST_HEAD(head);
+
+ spin_lock_irqsave(&chan->lock, flags);
+ list_for_each_entry_safe(desc, tmp, &chan->done, node)
+ if (async_tx_test_ack(&desc->async_tx) && desc->user_wait) {
+ list_move(&desc->node, &head);
+ desc->user_wait = false;
+ }
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ list_for_each_entry_safe(desc, tmp, &head, node) {
+ list_del(&desc->node);
+ nbpf_desc_put(desc);
+ }
+}
+
+/*
+ * We have to allocate descriptors with the channel lock dropped. This means,
+ * before we re-acquire the lock buffers can be taken already, so we have to
+ * re-check after re-acquiring the lock and possibly retry, if buffers are gone
+ * again.
+ */
+static struct nbpf_desc *nbpf_desc_get(struct nbpf_channel *chan, size_t len)
+{
+ struct nbpf_desc *desc = NULL;
+ struct nbpf_link_desc *ldesc, *prev = NULL;
+
+ nbpf_scan_acked(chan);
+
+ spin_lock_irq(&chan->lock);
+
+ do {
+ int i = 0, ret;
+
+ if (list_empty(&chan->free)) {
+ /* No more free descriptors */
+ spin_unlock_irq(&chan->lock);
+ ret = nbpf_desc_page_alloc(chan);
+ if (ret < 0)
+ return NULL;
+ spin_lock_irq(&chan->lock);
+ continue;
+ }
+ desc = list_first_entry(&chan->free, struct nbpf_desc, node);
+ list_del(&desc->node);
+
+ do {
+ if (list_empty(&chan->free_links)) {
+ /* No more free link descriptors */
+ spin_unlock_irq(&chan->lock);
+ ret = nbpf_desc_page_alloc(chan);
+ if (ret < 0) {
+ nbpf_desc_put(desc);
+ return NULL;
+ }
+ spin_lock_irq(&chan->lock);
+ continue;
+ }
+
+ ldesc = list_first_entry(&chan->free_links,
+ struct nbpf_link_desc, node);
+ ldesc->desc = desc;
+ if (prev)
+ prev->hwdesc->next = (u32)ldesc->hwdesc_dma_addr;
+
+ prev = ldesc;
+ list_move_tail(&ldesc->node, &desc->sg);
+
+ i++;
+ } while (i < len);
+ } while (!desc);
+
+ prev->hwdesc->next = 0;
+
+ spin_unlock_irq(&chan->lock);
+
+ return desc;
+}
+
+static void nbpf_chan_idle(struct nbpf_channel *chan)
+{
+ struct nbpf_desc *desc, *tmp;
+ unsigned long flags;
+ LIST_HEAD(head);
+
+ spin_lock_irqsave(&chan->lock, flags);
+
+ list_splice_init(&chan->done, &head);
+ list_splice_init(&chan->active, &head);
+ list_splice_init(&chan->queued, &head);
+
+ chan->running = NULL;
+
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ list_for_each_entry_safe(desc, tmp, &head, node) {
+ dev_dbg(chan->nbpf->dma_dev.dev, "%s(): force-free desc %p cookie %d\n",
+ __func__, desc, desc->async_tx.cookie);
+ list_del(&desc->node);
+ nbpf_cookie_fail(chan, desc->async_tx.cookie);
+ nbpf_desc_put(desc);
+ }
+}
+
+static int nbpf_control(struct dma_chan *dchan, enum dma_ctrl_cmd cmd,
+ unsigned long arg)
+{
+ struct nbpf_channel *chan = nbpf_to_chan(dchan);
+ struct dma_slave_config *config;
+
+ dev_dbg(dchan->device->dev, "Entry %s(%d)\n", __func__, cmd);
+
+ switch (cmd) {
+ case DMA_TERMINATE_ALL:
+ dev_dbg(dchan->device->dev, "Terminating\n");
+ nbpf_chan_halt(chan);
+ nbpf_chan_idle(chan);
+ break;
+ case DMA_SLAVE_CONFIG:
+ if (!arg)
+ return -EINVAL;
+ config = (struct dma_slave_config *)arg;
+
+ /*
+ * We could check config->slave_id to match chan->terminal here,
+ * but with DT they would be coming from the same source, so
+ * such a check would be superflous
+ */
+
+ switch (config->direction) {
+ case DMA_MEM_TO_DEV:
+ chan->slave_addr = config->dst_addr;
+ chan->slave_width = nbpf_xfer_size(chan->nbpf,
+ config->dst_addr_width, 1);
+ chan->slave_burst = nbpf_xfer_size(chan->nbpf,
+ config->dst_addr_width,
+ config->dst_maxburst);
+ break;
+ case DMA_DEV_TO_MEM:
+ chan->slave_addr = config->src_addr;
+ chan->slave_width = nbpf_xfer_size(chan->nbpf,
+ config->src_addr_width, 1);
+ chan->slave_burst = nbpf_xfer_size(chan->nbpf,
+ config->src_addr_width,
+ config->src_maxburst);
+ break;
+ default:
+ return -EINVAL;
+ }
+ break;
+ case DMA_PAUSE:
+ chan->paused = true;
+ nbpf_pause(chan);
+ break;
+ case DMA_RESUME:
+ /* Leave unimplemented until we get a use case. */
+ default:
+ return -ENXIO;
+ }
+
+ return 0;
+}
+
+static struct dma_async_tx_descriptor *nbpf_prep_sg(struct nbpf_channel *chan,
+ struct scatterlist *src_sg, struct scatterlist *dst_sg,
+ size_t len, enum dma_transfer_direction direction,
+ unsigned long flags)
+{
+ struct nbpf_link_desc *ldesc;
+ struct scatterlist *mem_sg;
+ struct nbpf_desc *desc;
+ bool inc_src, inc_dst;
+ int i = 0;
+
+ switch (direction) {
+ case DMA_DEV_TO_MEM:
+ mem_sg = dst_sg;
+ inc_src = false;
+ inc_dst = true;
+ break;
+ case DMA_MEM_TO_DEV:
+ mem_sg = src_sg;
+ inc_src = true;
+ inc_dst = false;
+ break;
+ default:
+ case DMA_MEM_TO_MEM:
+ mem_sg = src_sg;
+ inc_src = true;
+ inc_dst = true;
+ }
+
+ desc = nbpf_desc_get(chan, len);
+ if (!desc)
+ return NULL;
+
+ desc->async_tx.flags = flags;
+ desc->async_tx.cookie = -EBUSY;
+ desc->user_wait = false;
+
+ /*
+ * This is a private descriptor list, and we own the descriptor. No need
+ * to lock.
+ */
+ list_for_each_entry(ldesc, &desc->sg, node) {
+ int ret = nbpf_prep_one(ldesc, direction,
+ sg_dma_address(src_sg),
+ sg_dma_address(dst_sg),
+ sg_dma_len(mem_sg),
+ i == len - 1);
+ if (ret < 0) {
+ nbpf_desc_put(desc);
+ return NULL;
+ }
+ if (inc_src)
+ src_sg = sg_next(src_sg);
+ if (inc_dst)
+ dst_sg = sg_next(dst_sg);
+ mem_sg = direction == DMA_DEV_TO_MEM ? dst_sg : src_sg;
+ i++;
+ }
+
+ /* The user has to return the descriptor to us ASAP via .tx_submit() */
+ return &desc->async_tx;
+}
+
+static struct dma_async_tx_descriptor *nbpf_prep_memcpy(
+ struct dma_chan *dchan, dma_addr_t dst, dma_addr_t src,
+ size_t len, unsigned long flags)
+{
+ struct nbpf_channel *chan = nbpf_to_chan(dchan);
+ struct scatterlist dst_sg;
+ struct scatterlist src_sg;
+
+ sg_init_table(&dst_sg, 1);
+ sg_init_table(&src_sg, 1);
+
+ sg_dma_address(&dst_sg) = dst;
+ sg_dma_address(&src_sg) = src;
+
+ sg_dma_len(&dst_sg) = len;
+ sg_dma_len(&src_sg) = len;
+
+ dev_dbg(dchan->device->dev, "%s(): %u @ %pad -> %pad\n",
+ __func__, len, &src, &dst);
+
+ return nbpf_prep_sg(chan, &src_sg, &dst_sg, 1,
+ DMA_MEM_TO_MEM, flags);
+}
+
+static struct dma_async_tx_descriptor *nbpf_prep_memcpy_sg(
+ struct dma_chan *dchan,
+ struct scatterlist *dst_sg, unsigned int dst_nents,
+ struct scatterlist *src_sg, unsigned int src_nents,
+ unsigned long flags)
+{
+ struct nbpf_channel *chan = nbpf_to_chan(dchan);
+
+ if (dst_nents != src_nents)
+ return NULL;
+
+ return nbpf_prep_sg(chan, src_sg, dst_sg, src_nents,
+ DMA_MEM_TO_MEM, flags);
+}
+
+static struct dma_async_tx_descriptor *nbpf_prep_slave_sg(
+ struct dma_chan *dchan, struct scatterlist *sgl, unsigned int sg_len,
+ enum dma_transfer_direction direction, unsigned long flags, void *context)
+{
+ struct nbpf_channel *chan = nbpf_to_chan(dchan);
+ struct scatterlist slave_sg;
+
+ dev_dbg(dchan->device->dev, "Entry %s()\n", __func__);
+
+ sg_init_table(&slave_sg, 1);
+ sg_dma_address(&slave_sg) = chan->slave_addr;
+
+ switch (direction) {
+ case DMA_MEM_TO_DEV:
+ return nbpf_prep_sg(chan, sgl, &slave_sg, sg_len,
+ direction, flags);
+ case DMA_DEV_TO_MEM:
+ return nbpf_prep_sg(chan, &slave_sg, sgl, sg_len,
+ direction, flags);
+ default:
+ return NULL;
+ }
+}
+
+static int nbpf_alloc_chan_resources(struct dma_chan *dchan)
+{
+ struct nbpf_channel *chan = nbpf_to_chan(dchan);
+ int ret;
+
+ INIT_LIST_HEAD(&chan->free);
+ INIT_LIST_HEAD(&chan->free_links);
+ INIT_LIST_HEAD(&chan->queued);
+ INIT_LIST_HEAD(&chan->active);
+ INIT_LIST_HEAD(&chan->done);
+
+ memset(chan->status, 0, sizeof(chan->status));
+
+ ret = nbpf_desc_page_alloc(chan);
+ if (ret < 0)
+ return ret;
+
+ dev_dbg(dchan->device->dev, "Entry %s(): terminal %u\n", __func__,
+ chan->terminal);
+
+ nbpf_chan_configure(chan);
+
+ return ret;
+}
+
+static void nbpf_free_chan_resources(struct dma_chan *dchan)
+{
+ struct nbpf_channel *chan = nbpf_to_chan(dchan);
+ struct nbpf_desc_page *dpage, *tmp;
+
+ dev_dbg(dchan->device->dev, "Entry %s()\n", __func__);
+
+ nbpf_chan_halt(chan);
+ /* Clean up for if a channel is re-used for MEMCPY after slave DMA */
+ nbpf_chan_prepare_default(chan);
+
+ list_for_each_entry_safe(dpage, tmp, &chan->desc_page, node) {
+ struct nbpf_link_desc *ldesc;
+ int i;
+ list_del(&dpage->node);
+ for (i = 0, ldesc = dpage->ldesc;
+ i < ARRAY_SIZE(dpage->ldesc);
+ i++, ldesc++)
+ dma_unmap_single(dchan->device->dev, ldesc->hwdesc_dma_addr,
+ sizeof(*ldesc->hwdesc), DMA_TO_DEVICE);
+ free_page((unsigned long)dpage);
+ }
+}
+
+static int nbpf_slave_caps(struct dma_chan *dchan,
+ struct dma_slave_caps *caps)
+{
+ caps->src_addr_widths = NBPF_DMA_BUSWIDTHS;
+ caps->dstn_addr_widths = NBPF_DMA_BUSWIDTHS;
+ caps->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+ caps->cmd_pause = false;
+ caps->cmd_terminate = true;
+
+ return 0;
+}
+
+static bool nbpf_dma_filter(struct dma_chan *chan, void *param)
+{
+ return param == chan->device->dev->of_node;
+}
+
+static struct dma_chan *nbpf_of_xlate(struct of_phandle_args *dma_spec,
+ struct of_dma *ofdma)
+{
+ dma_cap_mask_t mask;
+ struct dma_chan *dchan;
+ struct nbpf_channel *chan;
+
+ if (dma_spec->args_count != 2)
+ return NULL;
+
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+
+ dchan = dma_request_channel(mask, nbpf_dma_filter, ofdma->of_node);
+ if (!dchan)
+ return NULL;
+
+ dev_dbg(dchan->device->dev, "Entry %s(%s)\n", __func__,
+ dma_spec->np->name);
+
+ chan = nbpf_to_chan(dchan);
+
+ chan->terminal = dma_spec->args[0];
+ chan->flags = dma_spec->args[1];
+
+ nbpf_chan_prepare(chan);
+ nbpf_chan_configure(chan);
+
+ return dchan;
+}
+
+static irqreturn_t nbpf_chan_irqt(int irq, void *dev)
+{
+ struct nbpf_channel *chan = dev;
+ struct nbpf_desc *desc, *tmp;
+ dma_async_tx_callback callback;
+ void *param;
+
+ while (!list_empty(&chan->done)) {
+ bool found = false, must_put, recycling = false;
+
+ spin_lock_irq(&chan->lock);
+
+ list_for_each_entry_safe(desc, tmp, &chan->done, node) {
+ if (!desc->user_wait) {
+ /* Newly completed descriptor, have to process */
+ found = true;
+ break;
+ } else if (async_tx_test_ack(&desc->async_tx)) {
+ /*
+ * This descriptor was waiting for a user ACK,
+ * it can be recycled now.
+ */
+ list_del(&desc->node);
+ spin_unlock_irq(&chan->lock);
+ nbpf_desc_put(desc);
+ recycling = true;
+ break;
+ }
+ }
+
+ if (recycling)
+ continue;
+
+ if (!found) {
+ /* This can happen if TERMINATE_ALL has been called */
+ spin_unlock_irq(&chan->lock);
+ break;
+ }
+
+ dev_dbg(chan->dma_chan.device->dev,
+ "%s(): chan %p #%d: cookie %d complete\n",
+ __func__, &chan->dma_chan, chan - chan->nbpf->chan,
+ desc->async_tx.cookie);
+ dma_cookie_complete(&desc->async_tx);
+
+ /*
+ * With released lock we cannot dereference desc, maybe it's
+ * still on the "done" list
+ */
+ if (async_tx_test_ack(&desc->async_tx)) {
+ list_del(&desc->node);
+ must_put = true;
+ } else {
+ desc->user_wait = true;
+ must_put = false;
+ }
+
+ callback = desc->async_tx.callback;
+ param = desc->async_tx.callback_param;
+
+ nbpf_cookie_success(chan, desc->async_tx.cookie);
+
+ /* ack and callback completed descriptor */
+ spin_unlock_irq(&chan->lock);
+
+ if (callback)
+ callback(param);
+
+ if (must_put)
+ nbpf_desc_put(desc);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t nbpf_chan_irq(int irq, void *dev)
+{
+ struct nbpf_channel *chan = dev;
+ bool done = nbpf_status_get(chan);
+ struct nbpf_desc *desc;
+ irqreturn_t ret;
+
+ if (!done)
+ return IRQ_NONE;
+
+ nbpf_status_ack(chan);
+
+ dev_dbg(&chan->dma_chan.dev->device, "%s()\n", __func__);
+
+ spin_lock(&chan->lock);
+ desc = chan->running;
+ if (WARN_ON(!desc)) {
+ ret = IRQ_NONE;
+ goto unlock;
+ } else {
+ ret = IRQ_WAKE_THREAD;
+ }
+
+ list_move_tail(&desc->node, &chan->done);
+ chan->running = NULL;
+
+ if (!list_empty(&chan->active)) {
+ desc = list_first_entry(&chan->active,
+ struct nbpf_desc, node);
+ if (!nbpf_start(desc))
+ chan->running = desc;
+ }
+
+unlock:
+ spin_unlock(&chan->lock);
+
+ return ret;
+}
+
+static irqreturn_t nbpf_err_irq(int irq, void *dev)
+{
+ struct nbpf_device *nbpf = dev;
+ u32 error = nbpf_error_get(nbpf);
+
+ dev_warn(nbpf->dma_dev.dev, "DMA error IRQ %u\n", irq);
+
+ if (!error)
+ return IRQ_NONE;
+
+ do {
+ struct nbpf_channel *chan = nbpf_error_get_channel(nbpf, error);
+ /* On error: abort all queued transfers, no callback */
+ nbpf_error_clear(chan);
+ nbpf_chan_idle(chan);
+ error = nbpf_error_get(nbpf);
+ } while (error);
+
+ return IRQ_HANDLED;
+}
+
+static int nbpf_chan_probe(struct nbpf_device *nbpf, int n)
+{
+ struct dma_device *dma_dev = &nbpf->dma_dev;
+ struct nbpf_channel *chan = nbpf->chan + n;
+ int ret;
+
+ chan->nbpf = nbpf;
+ chan->base = nbpf->base + NBPF_REG_CHAN_OFFSET + NBPF_REG_CHAN_SIZE * n;
+ INIT_LIST_HEAD(&chan->desc_page);
+ spin_lock_init(&chan->lock);
+ chan->dma_chan.device = dma_dev;
+ dma_cookie_init(&chan->dma_chan);
+ nbpf_chan_prepare_default(chan);
+
+ dev_dbg(dma_dev->dev, "%s(): channel %d: -> %p\n", __func__, n, chan->base);
+
+ snprintf(chan->name, sizeof(chan->name), "nbpf %d", n);
+
+ ret = devm_request_threaded_irq(dma_dev->dev, chan->irq,
+ nbpf_chan_irq, nbpf_chan_irqt, IRQF_SHARED,
+ chan->name, chan);
+ if (ret < 0)
+ return ret;
+
+ /* Add the channel to DMA device channel list */
+ list_add_tail(&chan->dma_chan.device_node,
+ &dma_dev->channels);
+
+ return 0;
+}
+
+static const struct of_device_id nbpf_match[] = {
+ {.compatible = "renesas,nbpfaxi64dmac1b4", .data = &nbpf_cfg[NBPF1B4]},
+ {.compatible = "renesas,nbpfaxi64dmac1b8", .data = &nbpf_cfg[NBPF1B8]},
+ {.compatible = "renesas,nbpfaxi64dmac1b16", .data = &nbpf_cfg[NBPF1B16]},
+ {.compatible = "renesas,nbpfaxi64dmac4b4", .data = &nbpf_cfg[NBPF4B4]},
+ {.compatible = "renesas,nbpfaxi64dmac4b8", .data = &nbpf_cfg[NBPF4B8]},
+ {.compatible = "renesas,nbpfaxi64dmac4b16", .data = &nbpf_cfg[NBPF4B16]},
+ {.compatible = "renesas,nbpfaxi64dmac8b4", .data = &nbpf_cfg[NBPF8B4]},
+ {.compatible = "renesas,nbpfaxi64dmac8b8", .data = &nbpf_cfg[NBPF8B8]},
+ {.compatible = "renesas,nbpfaxi64dmac8b16", .data = &nbpf_cfg[NBPF8B16]},
+ {}
+};
+MODULE_DEVICE_TABLE(of, nbpf_match);
+
+static int nbpf_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ const struct of_device_id *of_id = of_match_device(nbpf_match, dev);
+ struct device_node *np = dev->of_node;
+ struct nbpf_device *nbpf;
+ struct dma_device *dma_dev;
+ struct resource *iomem, *irq_res;
+ const struct nbpf_config *cfg;
+ int num_channels;
+ int ret, irq, eirq, i;
+ int irqbuf[9] /* maximum 8 channels + error IRQ */;
+ unsigned int irqs = 0;
+
+ BUILD_BUG_ON(sizeof(struct nbpf_desc_page) > PAGE_SIZE);
+
+ /* DT only */
+ if (!np || !of_id || !of_id->data)
+ return -ENODEV;
+
+ cfg = of_id->data;
+ num_channels = cfg->num_channels;
+
+ nbpf = devm_kzalloc(dev, sizeof(*nbpf) + num_channels *
+ sizeof(nbpf->chan[0]), GFP_KERNEL);
+ if (!nbpf) {
+ dev_err(dev, "Memory allocation failed\n");
+ return -ENOMEM;
+ }
+ dma_dev = &nbpf->dma_dev;
+ dma_dev->dev = dev;
+
+ iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ nbpf->base = devm_ioremap_resource(dev, iomem);
+ if (IS_ERR(nbpf->base))
+ return PTR_ERR(nbpf->base);
+
+ nbpf->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(nbpf->clk))
+ return PTR_ERR(nbpf->clk);
+
+ nbpf->config = cfg;
+
+ for (i = 0; irqs < ARRAY_SIZE(irqbuf); i++) {
+ irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
+ if (!irq_res)
+ break;
+
+ for (irq = irq_res->start; irq <= irq_res->end;
+ irq++, irqs++)
+ irqbuf[irqs] = irq;
+ }
+
+ dev_dbg(dev, "%s(): mapped %x -> %p\n", __func__, iomem->start, nbpf->base);
+
+ /*
+ * 3 IRQ resource schemes are supported:
+ * 1. 1 shared IRQ for error and all channels
+ * 2. 2 IRQs: one for error and one shared for all channels
+ * 3. 1 IRQ for error and an own IRQ for each channel
+ */
+ if (irqs != 1 && irqs != 2 && irqs != num_channels + 1)
+ return -ENXIO;
+
+ if (irqs == 1) {
+ eirq = irqbuf[0];
+
+ for (i = 0; i <= num_channels; i++)
+ nbpf->chan[i].irq = irqbuf[0];
+ } else {
+ eirq = platform_get_irq_byname(pdev, "error");
+ if (eirq < 0)
+ return eirq;
+
+ if (irqs == num_channels + 1) {
+ struct nbpf_channel *chan;
+
+ for (i = 0, chan = nbpf->chan; i <= num_channels;
+ i++, chan++) {
+ /* Skip the error IRQ */
+ if (irqbuf[i] == eirq)
+ i++;
+ chan->irq = irqbuf[i];
+ }
+
+ if (chan != nbpf->chan + num_channels)
+ return -EINVAL;
+ } else {
+ /* 2 IRQs and more than one channel */
+ if (irqbuf[0] == eirq)
+ irq = irqbuf[1];
+ else
+ irq = irqbuf[0];
+
+ for (i = 0; i <= num_channels; i++)
+ nbpf->chan[i].irq = irq;
+ }
+ }
+
+ ret = devm_request_irq(dev, eirq, nbpf_err_irq,
+ IRQF_SHARED, "dma error", nbpf);
+ if (ret < 0)
+ return ret;
+
+ INIT_LIST_HEAD(&dma_dev->channels);
+
+ /* Create DMA Channel */
+ for (i = 0; i < num_channels; i++) {
+ ret = nbpf_chan_probe(nbpf, i);
+ if (ret < 0)
+ return ret;
+ }
+
+ dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
+ dma_cap_set(DMA_SLAVE, dma_dev->cap_mask);
+ dma_cap_set(DMA_SG, dma_dev->cap_mask);
+
+ /* Common and MEMCPY operations */
+ dma_dev->device_alloc_chan_resources
+ = nbpf_alloc_chan_resources;
+ dma_dev->device_free_chan_resources = nbpf_free_chan_resources;
+ dma_dev->device_prep_dma_sg = nbpf_prep_memcpy_sg;
+ dma_dev->device_prep_dma_memcpy = nbpf_prep_memcpy;
+ dma_dev->device_tx_status = nbpf_tx_status;
+ dma_dev->device_issue_pending = nbpf_issue_pending;
+ dma_dev->device_slave_caps = nbpf_slave_caps;
+
+ /*
+ * If we drop support for unaligned MEMCPY buffer addresses and / or
+ * lengths by setting
+ * dma_dev->copy_align = 4;
+ * then we can set transfer length to 4 bytes in nbpf_prep_one() for
+ * DMA_MEM_TO_MEM
+ */
+
+ /* Compulsory for DMA_SLAVE fields */
+ dma_dev->device_prep_slave_sg = nbpf_prep_slave_sg;
+ dma_dev->device_control = nbpf_control;
+
+ platform_set_drvdata(pdev, nbpf);
+
+ ret = clk_prepare_enable(nbpf->clk);
+ if (ret < 0)
+ return ret;
+
+ nbpf_configure(nbpf);
+
+ ret = dma_async_device_register(dma_dev);
+ if (ret < 0)
+ goto e_clk_off;
+
+ ret = of_dma_controller_register(np, nbpf_of_xlate, pdev);
+ if (ret < 0)
+ goto e_dma_dev_unreg;
+
+ return 0;
+
+e_dma_dev_unreg:
+ dma_async_device_unregister(dma_dev);
+e_clk_off:
+ clk_disable_unprepare(nbpf->clk);
+
+ return ret;
+}
+
+static int nbpf_remove(struct platform_device *pdev)
+{
+ struct nbpf_device *nbpf = platform_get_drvdata(pdev);
+
+ of_dma_controller_free(pdev->dev.of_node);
+ dma_async_device_unregister(&nbpf->dma_dev);
+ clk_disable_unprepare(nbpf->clk);
+
+ return 0;
+}
+
+static struct platform_device_id nbpf_ids[] = {
+ {"nbpfaxi64dmac1b4", (kernel_ulong_t)&nbpf_cfg[NBPF1B4]},
+ {"nbpfaxi64dmac1b8", (kernel_ulong_t)&nbpf_cfg[NBPF1B8]},
+ {"nbpfaxi64dmac1b16", (kernel_ulong_t)&nbpf_cfg[NBPF1B16]},
+ {"nbpfaxi64dmac4b4", (kernel_ulong_t)&nbpf_cfg[NBPF4B4]},
+ {"nbpfaxi64dmac4b8", (kernel_ulong_t)&nbpf_cfg[NBPF4B8]},
+ {"nbpfaxi64dmac4b16", (kernel_ulong_t)&nbpf_cfg[NBPF4B16]},
+ {"nbpfaxi64dmac8b4", (kernel_ulong_t)&nbpf_cfg[NBPF8B4]},
+ {"nbpfaxi64dmac8b8", (kernel_ulong_t)&nbpf_cfg[NBPF8B8]},
+ {"nbpfaxi64dmac8b16", (kernel_ulong_t)&nbpf_cfg[NBPF8B16]},
+ {},
+};
+MODULE_DEVICE_TABLE(platform, nbpf_ids);
+
+#ifdef CONFIG_PM_RUNTIME
+static int nbpf_runtime_suspend(struct device *dev)
+{
+ struct nbpf_device *nbpf = platform_get_drvdata(to_platform_device(dev));
+ clk_disable_unprepare(nbpf->clk);
+ return 0;
+}
+
+static int nbpf_runtime_resume(struct device *dev)
+{
+ struct nbpf_device *nbpf = platform_get_drvdata(to_platform_device(dev));
+ return clk_prepare_enable(nbpf->clk);
+}
+#endif
+
+static const struct dev_pm_ops nbpf_pm_ops = {
+ SET_RUNTIME_PM_OPS(nbpf_runtime_suspend, nbpf_runtime_resume, NULL)
+};
+
+static struct platform_driver nbpf_driver = {
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "dma-nbpf",
+ .of_match_table = nbpf_match,
+ .pm = &nbpf_pm_ops,
+ },
+ .id_table = nbpf_ids,
+ .probe = nbpf_probe,
+ .remove = nbpf_remove,
+};
+
+module_platform_driver(nbpf_driver);
+
+MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@xxxxxx>");
+MODULE_DESCRIPTION("dmaengine driver for NBPFAXI64* DMACs");
+MODULE_LICENSE("GPL v2");
diff --git a/include/dt-bindings/dma/nbpfaxi.h b/include/dt-bindings/dma/nbpfaxi.h
new file mode 100644
index 0000000..74f2054
--- /dev/null
+++ b/include/dt-bindings/dma/nbpfaxi.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) 2013-2014 Renesas Electronics Europe Ltd.
+ * Author: Guennadi Liakhovetski <g.liakhovetski@xxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef DT_BINDINGS_NBPFAXI_H
+#define DT_BINDINGS_NBPFAXI_H
+
+/**
+ * Use "#dma-cells = <2>;" with the second integer defining slave DMA flags:
+ */
+#define NBPF_SLAVE_RQ_HIGH 1
+#define NBPF_SLAVE_RQ_LOW 2
+#define NBPF_SLAVE_RQ_LEVEL 4
+
+#endif
--
1.9.2
--
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