Hi Andriy, Thanks for the review. On Mon, 14 Apr 2014, Shevchenko, Andriy wrote: > On Sat, 2014-04-12 at 19:39 +0200, Guennadi Liakhovetski wrote: > > 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@xxxxxx> > > --- > > > > Tested on a Xilinx zc706-based board with an SD-host (driver will be > > submitted shortly) and a PL011 UART. > > > > Documentation/devicetree/bindings/dma/nbpfaxi.txt | 61 + > > drivers/dma/Kconfig | 6 + > > drivers/dma/Makefile | 1 + > > drivers/dma/nbpfaxi.c | 1554 +++++++++++++++++++++ > > include/dt-bindings/dma/nbpfaxi.h | 20 + > > 5 files changed, 1642 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..152bb13 > > --- /dev/null > > +++ b/drivers/dma/nbpfaxi.c > > @@ -0,0 +1,1554 @@ > > +/* > > + * Copyright (C) 2013-2014 Renesas 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; > > Are you sure about this? IIUC this is about what hardware has. > dma_addr_t is variable_sized type. If it's correct, then you have to use > %pad in printk's across your code. > > Otherwise use static length types like u32. It's used to store a return value of dma_map_single() and as an argument to dma_sync_single_for_device() and dma_unmap_single(). and it's also used to write to the hardware. So, I think it's better to keep the current type, but to add explicit casts, where it goes to hardware and use appropriate printk() formats, as you're suggesting. > > + 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; > > + u32 slave_width; > > + u32 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); > > + pr_debug("%s(0x%p + 0x%x) = 0x%x\n", __func__, chan->base, offset, data); > > Could you use dev_vdbg() for those prints? Ok > > + return data; > > +} > > + > > +static inline void nbpf_chan_write(struct nbpf_channel *chan, > > + unsigned int offset, u32 data) > > +{ > > + iowrite32(data, chan->base + offset); > > + pr_debug("%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); > > + pr_debug("%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); > > + pr_debug("%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 */ > > Maybe first letter capital? Sure :) > > + nbpf_chan_halt(chan); > > + > > + for (i = 0; i < 1000; i++) { > > + status = nbpf_chan_read(chan, NBPF_CHAN_STAT); > > + if (!(status & NBPF_CHAN_STAT_TACT)) > > + break; > > + cpu_relax(); > > + } > > + > > + if (i == 1000) > > + dev_err(chan->dma_chan.device->dev, "%s() abort timeout\n", __func__); > > You may simplify this stub by using countdown while loop. Like > > int i = 1000; > > while (--i && read() & CUSTOM_BIT) > cpu_relax(); > > if (!i) > "timeout"; Well, I'll make it a countdown loop, just to replace "i < 1000" with "i" and "i == 1000" with "!i" which do look a bit nicer. But I'll keep the "status" variable and to justify it I'll pring it out in the error message. > > + > > + 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, 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 u32 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); > > min_t? The compiler didn't complain, but it might, if size_t isn't compatible with u32 on some arches, so, I changed .slave_burst and .slave_width to size_t too. > > + > > + 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 @ 0x%x: hdr 0x%x, cfg 0x%x, %u @ 0x%x -> 0x%x\n", > > %pad for src and dst, please. Ok > > + __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 %p to %u\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 = 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 > > Capital letter first? ok > > + * 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 @ 0x%x -> 0x%x\n", > > %pad for dma_addr_t. yep > > + __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; > > + int pdev_id = to_platform_device(dma_dev->dev)->id; > > + 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); > > + > > + if (pdev_id >= 0) > > + snprintf(chan->name, sizeof(chan->name), > > + "nbpf %d.%d", pdev_id, n); > > Is there real case when platform device created with explicit ID > assignment? Maybe not, can be removed. > > + else > > + 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_threaded_irq(dev, eirq, nbpf_err_irq, NULL, > > + IRQF_SHARED, "dma error", nbpf); > > devm_request_irq since NULL ? ok > > + 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; > > + > > + if (np) { > > + ret = of_dma_controller_register(np, nbpf_of_xlate, pdev); > > + if (ret < 0) > > + return ret; > > + } > > I think it's better to call this after dma_async_device_register(). Yes, makes sense. > > + > > + platform_set_drvdata(pdev, nbpf); > > + > > + ret = clk_prepare_enable(nbpf->clk); > > + if (ret < 0) > > + goto e_of_unreg; > > + > > + nbpf_configure(nbpf); > > + > > + ret = dma_async_device_register(dma_dev); > > + if (ret < 0) > > + goto e_clk_off; > > + > > + return 0; > > + > > +e_clk_off: > > + clk_disable_unprepare(nbpf->clk); > > +e_of_unreg: > > + of_dma_controller_free(np); > > + > > + return ret; > > +} > > + > > +static int nbpf_remove(struct platform_device *pdev) > > +{ > > + struct nbpf_device *nbpf = platform_get_drvdata(pdev); > > + > > + dma_async_device_unregister(&nbpf->dma_dev); > > + clk_disable_unprepare(nbpf->clk); > > + of_dma_controller_free(pdev->dev.of_node); > > + > > + 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 Renesas 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 > > -- > > 1.9.1 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe dmaengine" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > -- > Andy Shevchenko <andriy.shevchenko@xxxxxxxxx> > Intel Finland Oy Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/ -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html