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Message-ID: <1394028474.28803.172.camel@smile.fi.intel.com>
Date: Wed, 5 Mar 2014 14:07:55 +0000
From: "Shevchenko, Andriy" <andriy.shevchenko@...el.com>
To: Maxime Ripard <maxime.ripard@...e-electrons.com>
CC: Emilio Lopez <emilio@...pez.com.ar>,
"Williams, Dan J" <dan.j.williams@...el.com>,
"Koul, Vinod" <vinod.koul@...el.com>,
"Mike Turquette" <mturquette@...aro.org>,
"linux-arm-kernel@...ts.infradead.org"
<linux-arm-kernel@...ts.infradead.org>,
"dmaengine@...r.kernel.org" <dmaengine@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
"linux-sunxi@...glegroups.com" <linux-sunxi@...glegroups.com>,
"kevin.z.m.zh@...il.com" <kevin.z.m.zh@...il.com>,
"sunny@...winnertech.com" <sunny@...winnertech.com>,
"shuge@...winnertech.com" <shuge@...winnertech.com>,
"zhuzhenhua@...winnertech.com" <zhuzhenhua@...winnertech.com>
Subject: Re: [PATCH v3 6/7] DMA: sun6i: Add driver for the Allwinner A31 DMA
controller
On Tue, 2014-03-04 at 17:18 +0100, Maxime Ripard wrote:
> The Allwinner A31 has a 16 channels DMA controller that it shares with the
> newer A23. Although sharing some similarities with the DMA controller of the
> older Allwinner SoCs, it's significantly different, I don't expect it to be
> possible to share the driver for these two.
>
> The A31 Controller is able to memory-to-memory or memory-to-device transfers on
> the 16 channels in parallel.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@...e-electrons.com>
> ---
> .../devicetree/bindings/dma/sun6i-dma.txt | 45 +
> drivers/dma/Kconfig | 8 +
> drivers/dma/Makefile | 1 +
> drivers/dma/sun6i-dma.c | 979 +++++++++++++++++++++
> 4 files changed, 1033 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/dma/sun6i-dma.txt
> create mode 100644 drivers/dma/sun6i-dma.c
>
> diff --git a/Documentation/devicetree/bindings/dma/sun6i-dma.txt b/Documentation/devicetree/bindings/dma/sun6i-dma.txt
> new file mode 100644
> index 0000000..5d7c86d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/sun6i-dma.txt
> @@ -0,0 +1,45 @@
> +Allwinner A31 DMA Controller
> +
> +This driver follows the generic DMA bindings defined in dma.txt.
> +
> +Required properties:
> +
> +- compatible: Must be "allwinner,sun6i-a31-dma"
> +- reg: Should contain the registers base address and length
> +- interrupts: Should contain a reference to the interrupt used by this device
> +- clocks: Should contain a reference to the parent AHB clock
> +- resets: Should contain a reference to the reset controller asserting
> + this device in reset
> +- #dma-cells : Should be 1, a single cell holding a line request number
> +
> +Example:
> + dma: dma-controller@...02000 {
> + compatible = "allwinner,sun6i-a31-dma";
> + reg = <0x01c02000 0x1000>;
> + interrupts = <0 50 4>;
> + clocks = <&ahb1_gates 6>;
> + resets = <&ahb1_rst 6>;
> + #dma-cells = <1>;
> + };
> +
> +Clients:
> +
> +DMA clients connected to the A31 DMA controller must use the format
> +described in the dma.txt file, using a two-cell specifier for each
> +channel: a phandle plus one integer cells.
> +The two cells in order are:
> +
> +1. A phandle pointing to the DMA controller.
> +2. The port ID as specified in the datasheet
> +
> +Example:
> +spi2: spi@...6a000 {
> + compatible = "allwinner,sun6i-a31-spi";
> + reg = <0x01c6a000 0x1000>;
> + interrupts = <0 67 4>;
> + clocks = <&ahb1_gates 22>, <&spi2_clk>;
> + clock-names = "ahb", "mod";
> + dmas = <&dma 25>, <&dma 25>;
> + dma-names = "rx", "tx";
> + resets = <&ahb1_rst 22>;
> +};
> diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
> index 605b016..7923697 100644
> --- a/drivers/dma/Kconfig
> +++ b/drivers/dma/Kconfig
> @@ -351,6 +351,14 @@ config MOXART_DMA
> help
> Enable support for the MOXA ART SoC DMA controller.
>
> +config DMA_SUN6I
> + tristate "Allwinner A31 SoCs DMA support"
> + depends on ARCH_SUNXI
> + select DMA_ENGINE
> + select DMA_VIRTUAL_CHANNELS
> + help
> + Support for the DMA engine for Allwinner A31 SoCs.
> +
> config DMA_ENGINE
> bool
>
> diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
> index a029d0f4..18cdbad 100644
> --- a/drivers/dma/Makefile
> +++ b/drivers/dma/Makefile
> @@ -44,3 +44,4 @@ obj-$(CONFIG_DMA_JZ4740) += dma-jz4740.o
> obj-$(CONFIG_TI_CPPI41) += cppi41.o
> obj-$(CONFIG_K3_DMA) += k3dma.o
> obj-$(CONFIG_MOXART_DMA) += moxart-dma.o
> +obj-$(CONFIG_DMA_SUN6I) += sun6i-dma.o
> diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
> new file mode 100644
> index 0000000..92cd1f3
> --- /dev/null
> +++ b/drivers/dma/sun6i-dma.c
> @@ -0,0 +1,979 @@
> +/*
> + * Copyright (C) 2013-2014 Allwinner Tech Co., Ltd
> + * Author: Sugar <shuge@...winnertech.com>
> + *
> + * Copyright (C) 2014 Maxime Ripard
> + * Maxime Ripard <maxime.ripard@...e-electrons.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/dmaengine.h>
> +#include <linux/dmapool.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/of_dma.h>
> +#include <linux/platform_device.h>
> +#include <linux/reset.h>
> +#include <linux/slab.h>
> +#include <linux/types.h>
> +
> +#include "virt-dma.h"
> +
> +/*
> + * There's 16 physical channels that can work in parallel.
> + *
> + * However we have 30 different endpoints for our requests.
> + *
> + * Since the channels are able to handle only an unidirectional
> + * transfer, we need to allocate more virtual channels so that
> + * everyone can grab one channel.
> + *
> + * Some devices can't work in both direction (mostly because it
> + * wouldn't make sense), so we have a bit fewer virtual channels than
> + * 2 channels per endpoints.
> + */
> +
> +#define NR_MAX_CHANNELS 16
> +#define NR_MAX_REQUESTS 30
> +#define NR_MAX_VCHANS 53
> +
> +/*
> + * Common registers
> + */
> +#define DMA_IRQ_EN(x) ((x) * 0x04)
> +#define DMA_IRQ_HALF BIT(0)
> +#define DMA_IRQ_PKG BIT(1)
> +#define DMA_IRQ_QUEUE BIT(2)
> +
> +#define DMA_IRQ_CHAN_NR 8
> +#define DMA_IRQ_CHAN_WIDTH 4
> +
> +
> +#define DMA_IRQ_STAT(x) ((x) * 0x04 + 0x10)
> +
> +#define DMA_STAT 0x30
> +
> +/*
> + * Channels specific registers
> + */
> +#define DMA_CHAN_ENABLE 0x00
> +#define DMA_CHAN_ENABLE_START BIT(0)
> +#define DMA_CHAN_ENABLE_STOP 0
> +
> +#define DMA_CHAN_PAUSE 0x04
> +#define DMA_CHAN_PAUSE_PAUSE BIT(1)
> +#define DMA_CHAN_PAUSE_RESUME 0
> +
> +#define DMA_CHAN_LLI_ADDR 0x08
> +
> +#define DMA_CHAN_CUR_CFG 0x0c
> +#define DMA_CHAN_CFG_SRC_DRQ(x) ((x) & 0x1f)
> +#define DMA_CHAN_CFG_SRC_IO_MODE BIT(5)
> +#define DMA_CHAN_CFG_SRC_LINEAR_MODE (0 << 5)
> +#define DMA_CHAN_CFG_SRC_BURST(x) (((x) & 0x3) << 7)
> +#define DMA_CHAN_CFG_SRC_WIDTH(x) (((x) & 0x3) << 9)
> +
> +#define DMA_CHAN_CFG_DST_DRQ(x) (DMA_CHAN_CFG_SRC_DRQ(x) << 16)
> +#define DMA_CHAN_CFG_DST_IO_MODE (DMA_CHAN_CFG_SRC_IO_MODE << 16)
> +#define DMA_CHAN_CFG_DST_LINEAR_MODE (DMA_CHAN_CFG_SRC_LINEAR_MODE << 16)
> +#define DMA_CHAN_CFG_DST_BURST(x) (DMA_CHAN_CFG_SRC_BURST(x) << 16)
> +#define DMA_CHAN_CFG_DST_WIDTH(x) (DMA_CHAN_CFG_SRC_WIDTH(x) << 16)
> +
> +#define DMA_CHAN_CUR_SRC 0x10
> +
> +#define DMA_CHAN_CUR_DST 0x14
> +
> +#define DMA_CHAN_CUR_CNT 0x18
> +
> +#define DMA_CHAN_CUR_PARA 0x1c
> +
> +
> +/*
> + * Various hardware related defines
> + */
> +#define LLI_LAST_ITEM 0xfffff800
> +#define NORMAL_WAIT 8
> +#define DRQ_SDRAM 1
> +
> +/*
> + * Hardware representation of the LLI
> + *
> + * The hardware will be fed the physical address of this structure,
> + * and read its content in order to start the transfer.
> + */
> +struct sun6i_dma_lli {
> + u32 cfg;
> + u32 src;
> + u32 dst;
> + u32 len;
> + u32 para;
> + u32 p_lli_next;
> + struct sun6i_dma_lli *v_lli_next;
> +} __packed;
> +
> +
> +struct sun6i_desc {
> + struct virt_dma_desc vd;
> + dma_addr_t p_lli;
> + struct sun6i_dma_lli *v_lli;
> +};
> +
> +struct sun6i_pchan {
> + u32 idx;
> + void __iomem *base;
> + struct sun6i_vchan *vchan;
> + struct sun6i_desc *desc;
> + struct sun6i_desc *done;
> +};
> +
> +struct sun6i_vchan {
> + struct virt_dma_chan vc;
> + struct list_head node;
> + struct dma_slave_config cfg;
> + struct sun6i_pchan *phy;
> + u8 port;
> +};
> +
> +struct sun6i_dma_dev {
> + struct dma_device slave;
> + void __iomem *base;
> + struct clk *clk;
> + struct reset_control *rstc;
> + spinlock_t lock;
> + struct tasklet_struct task;
> + struct list_head pending;
> + struct dma_pool *pool;
> + struct sun6i_pchan *pchans;
> + struct sun6i_vchan *vchans;
> +};
> +
> +static struct device *chan2dev(struct dma_chan *chan)
> +{
> + return &chan->dev->device;
> +}
> +
> +static inline struct sun6i_dma_dev *to_sun6i_dma_dev(struct dma_device *d)
> +{
> + return container_of(d, struct sun6i_dma_dev, slave);
> +}
> +
> +static inline struct sun6i_vchan *to_sun6i_vchan(struct dma_chan *chan)
> +{
> + return container_of(chan, struct sun6i_vchan, vc.chan);
> +}
> +
> +static inline struct sun6i_desc *
> +to_sun6i_desc(struct dma_async_tx_descriptor *tx)
> +{
> + return container_of(tx, struct sun6i_desc, vd.tx);
> +}
> +
> +static inline void sun6i_dma_dump_com_regs(struct sun6i_dma_dev *sdev)
> +{
> + dev_dbg(sdev->slave.dev, "Common register:\n"
> + "\tmask0(%04x): 0x%08x\n"
> + "\tmask1(%04x): 0x%08x\n"
> + "\tpend0(%04x): 0x%08x\n"
> + "\tpend1(%04x): 0x%08x\n"
> + "\tstats(%04x): 0x%08x\n",
> + DMA_IRQ_EN(0), readl(sdev->base + DMA_IRQ_EN(0)),
> + DMA_IRQ_EN(1), readl(sdev->base + DMA_IRQ_EN(1)),
> + DMA_IRQ_STAT(0), readl(sdev->base + DMA_IRQ_STAT(0)),
> + DMA_IRQ_STAT(1), readl(sdev->base + DMA_IRQ_STAT(1)),
> + DMA_STAT, readl(sdev->base + DMA_STAT));
> +}
> +
> +static inline void sun6i_dma_dump_chan_regs(struct sun6i_dma_dev *sdev,
> + struct sun6i_pchan *pchan)
> +{
> + dev_dbg(sdev->slave.dev, "Chan %d reg: %pa\n"
> + "\t___en(%04x): \t0x%08x\n"
> + "\tpause(%04x): \t0x%08x\n"
> + "\tstart(%04x): \t0x%08x\n"
> + "\t__cfg(%04x): \t0x%08x\n"
> + "\t__src(%04x): \t0x%08x\n"
> + "\t__dst(%04x): \t0x%08x\n"
> + "\tcount(%04x): \t0x%08x\n"
> + "\t_para(%04x): \t0x%08x\n\n",
> + pchan->idx, __virt_to_phys((unsigned long)pchan->base),
> + DMA_CHAN_ENABLE,
> + readl(pchan->base + DMA_CHAN_ENABLE),
> + DMA_CHAN_PAUSE,
> + readl(pchan->base + DMA_CHAN_PAUSE),
> + DMA_CHAN_LLI_ADDR,
> + readl(pchan->base + DMA_CHAN_LLI_ADDR),
> + DMA_CHAN_CUR_CFG,
> + readl(pchan->base + DMA_CHAN_CUR_CFG),
> + DMA_CHAN_CUR_SRC,
> + readl(pchan->base + DMA_CHAN_CUR_SRC),
> + DMA_CHAN_CUR_DST,
> + readl(pchan->base + DMA_CHAN_CUR_DST),
> + DMA_CHAN_CUR_CNT,
> + readl(pchan->base + DMA_CHAN_CUR_CNT),
> + DMA_CHAN_CUR_PARA,
> + readl(pchan->base + DMA_CHAN_CUR_PARA));
> +}
> +
> +static inline u8 convert_burst(u8 maxburst)
> +{
> + if (maxburst == 1 || maxburst > 16)
> + return 0;
> +
> + return fls(maxburst) - 1;
> +}
> +
> +static inline u8 convert_buswidth(enum dma_slave_buswidth addr_width)
> +{
> + switch (addr_width) {
> + case DMA_SLAVE_BUSWIDTH_2_BYTES:
> + return 1;
> + case DMA_SLAVE_BUSWIDTH_4_BYTES:
> + return 2;
> + default:
> + return 0;
> + }
> +}
> +
> +static void *sun6i_dma_lli_add(struct sun6i_dma_lli *prev,
> + struct sun6i_dma_lli *next,
> + dma_addr_t next_phy,
> + struct sun6i_desc *txd)
> +{
> + if ((!prev && !txd) || !next)
> + return NULL;
> +
> + if (!prev) {
> + txd->p_lli = next_phy;
> + txd->v_lli = next;
> + } else {
> + prev->p_lli_next = next_phy;
> + prev->v_lli_next = next;
> + }
> +
> + next->p_lli_next = LLI_LAST_ITEM;
> + next->v_lli_next = NULL;
> +
> + return next;
> +}
> +
> +static inline void sun6i_dma_cfg_lli(struct sun6i_dma_lli *lli,
> + dma_addr_t src,
> + dma_addr_t dst, u32 len,
> + struct dma_slave_config *config)
> +{
> + u32 src_width, dst_width, src_burst, dst_burst;
> +
> + if (!config)
> + return;
> +
> + src_burst = convert_burst(config->src_maxburst);
> + dst_burst = convert_burst(config->dst_maxburst);
> +
> + src_width = convert_buswidth(config->src_addr_width);
> + dst_width = convert_buswidth(config->dst_addr_width);
> +
> + lli->cfg = DMA_CHAN_CFG_SRC_BURST(src_burst) |
> + DMA_CHAN_CFG_SRC_WIDTH(src_width) |
> + DMA_CHAN_CFG_DST_BURST(dst_burst) |
> + DMA_CHAN_CFG_DST_WIDTH(dst_width);
> +
> + lli->src = src;
> + lli->dst = dst;
> + lli->len = len;
> + lli->para = NORMAL_WAIT;
> +
> +}
> +
> +static inline void sun6i_dma_dump_lli(struct sun6i_vchan *vchan,
> + struct sun6i_dma_lli *lli)
> +{
> + dev_dbg(chan2dev(&vchan->vc.chan),
> + "\n\tdesc: p - %pa v - 0x%08x\n"
> + "\t\tc - 0x%08x s - 0x%08x d - 0x%08x\n"
> + "\t\tl - 0x%08x p - 0x%08x n - 0x%08x\n",
> + __virt_to_phys((unsigned long)lli), (u32)lli,
> + lli->cfg, lli->src, lli->dst,
> + lli->len, lli->para, lli->p_lli_next);
> +}
> +
> +static void sun6i_dma_free_desc(struct virt_dma_desc *vd)
> +{
> + struct sun6i_desc *txd = to_sun6i_desc(&vd->tx);
> + struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(vd->tx.chan->device);
> + struct sun6i_dma_lli *v_lli, *v_next;
> + dma_addr_t p_lli, p_next;
> +
> + if (unlikely(!txd))
> + return;
> +
> + p_lli = txd->p_lli;
> + v_lli = txd->v_lli;
> +
> + while (v_lli) {
> + v_next = v_lli->v_lli_next;
> + p_next = v_lli->p_lli_next;
> +
> + dma_pool_free(sdev->pool, v_lli, p_lli);
> +
> + v_lli = v_next;
> + p_lli = p_next;
> + }
> +
> + kfree(txd);
> +}
> +
> +static int sun6i_dma_terminate_all(struct sun6i_vchan *vchan)
> +{
> + struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(vchan->vc.chan.device);
> + struct sun6i_pchan *pchan = vchan->phy;
> + unsigned long flags;
> + LIST_HEAD(head);
> +
> + spin_lock(&sdev->lock);
> + list_del_init(&vchan->node);
> + spin_unlock(&sdev->lock);
> +
> + spin_lock_irqsave(&vchan->vc.lock, flags);
> +
> + vchan_get_all_descriptors(&vchan->vc, &head);
> +
> + if (pchan) {
> + writel(DMA_CHAN_ENABLE_STOP, pchan->base + DMA_CHAN_ENABLE);
> + writel(DMA_CHAN_PAUSE_RESUME, pchan->base + DMA_CHAN_PAUSE);
> +
> + vchan->phy = NULL;
> + pchan->vchan = NULL;
> + pchan->desc = NULL;
> + pchan->done = NULL;
> + }
> +
> + spin_unlock_irqrestore(&vchan->vc.lock, flags);
> +
> + vchan_dma_desc_free_list(&vchan->vc, &head);
> +
> + return 0;
> +}
> +
> +static int sun6i_dma_start_desc(struct sun6i_vchan *vchan)
> +{
> + struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(vchan->vc.chan.device);
> + struct virt_dma_desc *desc = vchan_next_desc(&vchan->vc);
> + struct sun6i_pchan *pchan = vchan->phy;
> + u32 irq_val, irq_reg, irq_offset;
> +
> + if (!pchan)
> + return -EAGAIN;
> +
> + if (!desc) {
> + pchan->desc = NULL;
> + pchan->done = NULL;
> + return -EAGAIN;
> + }
> +
> + list_del(&desc->node);
> +
> + pchan->desc = to_sun6i_desc(&desc->tx);
> + pchan->done = NULL;
> +
> + sun6i_dma_dump_lli(vchan, pchan->desc->v_lli);
> +
> + irq_reg = pchan->idx / DMA_IRQ_CHAN_NR;
> + irq_offset = pchan->idx % DMA_IRQ_CHAN_NR;
> +
> + irq_val = readl(sdev->base + DMA_IRQ_EN(irq_offset));
> + irq_val |= DMA_IRQ_QUEUE << (irq_offset * DMA_IRQ_CHAN_WIDTH);
> + writel(irq_val, sdev->base + DMA_IRQ_EN(irq_offset));
> +
> + writel(pchan->desc->p_lli, pchan->base + DMA_CHAN_LLI_ADDR);
> + writel(DMA_CHAN_ENABLE_START, pchan->base + DMA_CHAN_ENABLE);
> +
> + sun6i_dma_dump_com_regs(sdev);
> + sun6i_dma_dump_chan_regs(sdev, pchan);
> +
> + return 0;
> +}
> +
> +static void sun6i_dma_tasklet(unsigned long data)
> +{
> + struct sun6i_dma_dev *sdev = (struct sun6i_dma_dev *)data;
> + struct sun6i_vchan *vchan;
> + struct sun6i_pchan *pchan;
> + unsigned int pchan_alloc = 0;
> + unsigned int pchan_idx;
> +
> + list_for_each_entry(vchan, &sdev->slave.channels, vc.chan.device_node) {
> + spin_lock_irq(&vchan->vc.lock);
> +
> + pchan = vchan->phy;
> +
> + if (pchan && pchan->done) {
> + if (sun6i_dma_start_desc(vchan)) {
> + /*
> + * No current txd associated with this channel
> + */
> + dev_dbg(sdev->slave.dev, "pchan %u: free\n",
> + pchan->idx);
> +
> + /* Mark this channel free */
> + vchan->phy = NULL;
> + pchan->vchan = NULL;
> + }
> + }
> + spin_unlock_irq(&vchan->vc.lock);
> + }
> +
> + spin_lock_irq(&sdev->lock);
> + for (pchan_idx = 0; pchan_idx < NR_MAX_CHANNELS; pchan_idx++) {
> + pchan = &sdev->pchans[pchan_idx];
> +
> + if (pchan->vchan == NULL && !list_empty(&sdev->pending)) {
> + vchan = list_first_entry(&sdev->pending,
> + struct sun6i_vchan, node);
> +
> + /* Remove from pending channels */
> + list_del_init(&vchan->node);
> + pchan_alloc |= BIT(pchan_idx);
> +
> + /* Mark this channel allocated */
> + pchan->vchan = vchan;
> + vchan->phy = pchan;
> + dev_dbg(sdev->slave.dev, "pchan %u: alloc vchan %p\n",
> + pchan->idx, &vchan->vc);
> + }
> + }
> + spin_unlock_irq(&sdev->lock);
> +
> + for (pchan_idx = 0; pchan_idx < NR_MAX_CHANNELS; pchan_idx++) {
> + if (pchan_alloc & BIT(pchan_idx)) {
> + pchan = sdev->pchans + pchan_idx;
> + vchan = pchan->vchan;
> + if (vchan) {
> + spin_lock_irq(&vchan->vc.lock);
> + sun6i_dma_start_desc(vchan);
> + spin_unlock_irq(&vchan->vc.lock);
> + }
> + }
> + }
> +}
> +
> +static irqreturn_t sun6i_dma_interrupt(int irq, void *dev_id)
> +{
> + struct sun6i_dma_dev *sdev = (struct sun6i_dma_dev *)dev_id;
Unneeded explicit casting.
> + struct sun6i_vchan *vchan;
> + struct sun6i_pchan *pchan;
> + int i, j, ret = IRQ_NONE;
> + u32 status;
> +
> + for (i = 0; i < 2; i++) {
> + status = readl(sdev->base + DMA_IRQ_STAT(i));
> + if (!status)
> + continue;
> +
> + dev_dbg(sdev->slave.dev, "DMA irq status %s: 0x%x\n",
> + i ? "high" : "low", status);
> +
> + writel(status, sdev->base + DMA_IRQ_STAT(i));
> +
> + for (j = 0; (j < 8) && status; j++) {
> + if (status & DMA_IRQ_QUEUE) {
> + pchan = sdev->pchans + j;
> + vchan = pchan->vchan;
> +
> + if (vchan) {
> + unsigned long flags;
> +
> + spin_lock_irqsave(&vchan->vc.lock,
> + flags);
> + vchan_cookie_complete(&pchan->desc->vd);
> + pchan->done = pchan->desc;
> + spin_unlock_irqrestore(&vchan->vc.lock,
> + flags);
> + }
> + }
> +
> + status = status >> 4;
> + }
> +
> + tasklet_schedule(&sdev->task);
> + ret = IRQ_HANDLED;
> + }
> +
> + return ret;
> +}
> +
> +static struct dma_async_tx_descriptor *sun6i_dma_prep_dma_memcpy(
> + struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
> + size_t len, unsigned long flags)
> +{
> + struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
> + struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
> + struct dma_slave_config *sconfig = &vchan->cfg;
> + struct sun6i_dma_lli *v_lli;
> + struct sun6i_desc *txd;
> + dma_addr_t p_lli;
> +
> + dev_dbg(chan2dev(chan),
> + "%s; chan: %d, dest: %pad, src: %pad, len: %zu. flags: 0x%08lx\n",
> + __func__, vchan->vc.chan.chan_id, dest, src, len, flags);
&desc, &src
%pa[d] use a reference. Please, recheck your code.
> +
> + if (!len)
> + return NULL;
> +
> + txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
> + if (!txd)
> + return NULL;
> +
> + v_lli = dma_pool_alloc(sdev->pool, GFP_NOWAIT, &p_lli);
> + if (!v_lli) {
> + dev_err(sdev->slave.dev, "Failed to alloc lli memory\n");
> + kfree(txd);
> + return NULL;
> + }
> +
> + sun6i_dma_cfg_lli(v_lli, src, dest, len, sconfig);
> + v_lli->cfg |= DMA_CHAN_CFG_SRC_DRQ(DRQ_SDRAM) |
> + DMA_CHAN_CFG_DST_DRQ(DRQ_SDRAM) |
> + DMA_CHAN_CFG_DST_LINEAR_MODE |
> + DMA_CHAN_CFG_SRC_LINEAR_MODE;
> +
> + sun6i_dma_lli_add(NULL, v_lli, p_lli, txd);
> +
> + sun6i_dma_dump_lli(vchan, v_lli);
> +
> + return vchan_tx_prep(&vchan->vc, &txd->vd, flags);
> +}
> +
> +static struct dma_async_tx_descriptor *sun6i_dma_prep_slave_sg(
> + struct dma_chan *chan, struct scatterlist *sgl,
> + unsigned int sg_len, enum dma_transfer_direction dir,
> + unsigned long flags, void *context)
> +{
> + struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
> + struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
> + struct dma_slave_config *sconfig = &vchan->cfg;
> + struct sun6i_dma_lli *v_lli, *prev = NULL;
> + struct sun6i_desc *txd;
> + struct scatterlist *sg;
> + dma_addr_t p_lli;
> + int i;
> +
> + if (!sgl)
> + return NULL;
> +
> + txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
> + if (!txd)
> + return NULL;
> +
> + for_each_sg(sgl, sg, sg_len, i) {
> + v_lli = dma_pool_alloc(sdev->pool, GFP_NOWAIT, &p_lli);
> + if (!v_lli) {
> + kfree(txd);
> + return NULL;
> + }
> +
> + if (dir == DMA_MEM_TO_DEV) {
> + sun6i_dma_cfg_lli(v_lli, sg_dma_address(sg),
> + sconfig->dst_addr, sg_dma_len(sg),
> + sconfig);
> + v_lli->cfg |= DMA_CHAN_CFG_DST_IO_MODE |
> + DMA_CHAN_CFG_SRC_LINEAR_MODE |
> + DMA_CHAN_CFG_SRC_DRQ(DRQ_SDRAM) |
> + DMA_CHAN_CFG_DST_DRQ(vchan->port);
> +
> + dev_dbg(chan2dev(chan),
> + "%s; chan: %d, dest: %pad, src: %pad, len: %zu. flags: 0x%08lx\n",
> + __func__, vchan->vc.chan.chan_id,
> + sconfig->dst_addr, sg_dma_address(sg),
> + sg_dma_len(sg), flags);
> +
> + } else if (dir == DMA_DEV_TO_MEM) {
> + sun6i_dma_cfg_lli(v_lli, sconfig->src_addr,
> + sg_dma_address(sg), sg_dma_len(sg),
> + sconfig);
> + v_lli->cfg |= DMA_CHAN_CFG_DST_LINEAR_MODE |
> + DMA_CHAN_CFG_SRC_IO_MODE |
> + DMA_CHAN_CFG_DST_DRQ(DRQ_SDRAM) |
> + DMA_CHAN_CFG_SRC_DRQ(vchan->port);
> +
> + dev_dbg(chan2dev(chan),
> + "%s; chan: %d, dest: %pad, src: %pad, len: %zu. flags: 0x%08lx\n",
> + __func__, vchan->vc.chan.chan_id,
> + sg_dma_address(sg), sconfig->src_addr,
> + sg_dma_len(sg), flags);
> + }
If direction is not slave, you may end up here with undefined values.
At the beginning of this function you probably can do something like
if (!is_slave_direction()) {
dev_err("Wrong direction");
return -EINVAL;
}
...and remove second if() in the condition.
> +
> + prev = sun6i_dma_lli_add(prev, v_lli, p_lli, txd);
> + }
> +
> +#ifdef DEBUG
> + dev_dbg(chan2dev(chan), "First: %pad\n", txd->p_lli);
> + for (prev = txd->v_lli; prev != NULL; prev = prev->v_lli_next)
> + sun6i_dma_dump_lli(vchan, prev);
> +#endif
> +
> + return vchan_tx_prep(&vchan->vc, &txd->vd, flags);
> +}
> +
> +static int sun6i_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
> + unsigned long arg)
> +{
> + struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
> + struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
> + struct sun6i_pchan *pchan = vchan->phy;
> + unsigned long flags;
> + int ret = 0;
> +
> + switch (cmd) {
> + case DMA_RESUME:
> + dev_dbg(chan2dev(chan), "vchan %p: resume\n", &vchan->vc);
> +
> + spin_lock_irqsave(&vchan->vc.lock, flags);
> +
> + if (pchan) {
> + writel(DMA_CHAN_PAUSE_RESUME,
> + pchan->base + DMA_CHAN_PAUSE);
> + } else if (!list_empty(&vchan->vc.desc_issued)) {
> + spin_lock(&sdev->lock);
> + list_add_tail(&vchan->node, &sdev->pending);
> + spin_unlock(&sdev->lock);
> + }
> +
> + spin_unlock_irqrestore(&vchan->vc.lock, flags);
> + break;
> +
> + case DMA_PAUSE:
> + dev_dbg(chan2dev(chan), "vchan %p: pause\n", &vchan->vc);
> +
> + if (pchan) {
> + writel(DMA_CHAN_PAUSE_PAUSE,
> + pchan->base + DMA_CHAN_PAUSE);
> + } else {
> + spin_lock(&sdev->lock);
> + list_del_init(&vchan->node);
> + spin_unlock(&sdev->lock);
> + }
> + break;
> +
> + case DMA_TERMINATE_ALL:
> + ret = sun6i_dma_terminate_all(vchan);
> + break;
> + case DMA_SLAVE_CONFIG:
> + memcpy(&vchan->cfg, (struct dma_slave_config *)arg,
> + sizeof(struct dma_slave_config));
> + break;
> + default:
> + ret = -ENXIO;
> + break;
> + }
> + return ret;
> +}
> +
> +static enum dma_status sun6i_dma_tx_status(struct dma_chan *chan,
> + dma_cookie_t cookie,
> + struct dma_tx_state *state)
> +{
> + struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
> + struct sun6i_pchan *pchan = vchan->phy;
> + struct sun6i_dma_lli *lli;
> + struct virt_dma_desc *vd;
> + struct sun6i_desc *txd;
> + enum dma_status ret;
> + unsigned long flags;
> + size_t bytes = 0;
> +
> + ret = dma_cookie_status(chan, cookie, state);
> + if (ret == DMA_COMPLETE)
> + return ret;
> +
> + spin_lock_irqsave(&vchan->vc.lock, flags);
> +
> + vd = vchan_find_desc(&vchan->vc, cookie);
> + txd = to_sun6i_desc(&vd->tx);
> +
> + if (vd) {
> + for (lli = txd->v_lli; lli != NULL; lli = lli->v_lli_next)
> + bytes += lli->len;
> + } else if (!pchan || !pchan->desc) {
> + bytes = 0;
> + } else {
> + bytes = readl(pchan->base + DMA_CHAN_CUR_CNT);
> + }
> +
> + spin_unlock_irqrestore(&vchan->vc.lock, flags);
> +
> + dma_set_residue(state, bytes);
> +
> + return ret;
> +}
> +
> +static void sun6i_dma_issue_pending(struct dma_chan *chan)
> +{
> + struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
> + struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
> + unsigned long flags;
> +
> + spin_lock_irqsave(&vchan->vc.lock, flags);
> +
> + if (vchan_issue_pending(&vchan->vc)) {
> + spin_lock(&sdev->lock);
> +
> + if (!vchan->phy) {
> + if (list_empty(&vchan->node)) {
if (cond1) {
if (cond2) {
}}
usually can be converted to if (cond1 && cond2) {}
> + list_add_tail(&vchan->node, &sdev->pending);
> + tasklet_schedule(&sdev->task);
> + dev_dbg(chan2dev(chan), "vchan %p: issued\n",
> + &vchan->vc);
> + }
> + }
> +
> + spin_unlock(&sdev->lock);
> + } else {
> + dev_dbg(chan2dev(chan), "vchan %p: nothing to issue\n",
> + &vchan->vc);
> + }
> +
> + spin_unlock_irqrestore(&vchan->vc.lock, flags);
> +}
> +
> +static int sun6i_dma_alloc_chan_resources(struct dma_chan *chan)
> +{
> + return 0;
> +}
> +
> +static void sun6i_dma_free_chan_resources(struct dma_chan *chan)
> +{
> + struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
> + struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
> + unsigned long flags;
> +
> + spin_lock_irqsave(&sdev->lock, flags);
> + list_del_init(&vchan->node);
> + spin_unlock_irqrestore(&sdev->lock, flags);
> +
> + vchan_free_chan_resources(&vchan->vc);
> +}
> +
> +static inline void sun6i_dma_free(struct sun6i_dma_dev *sdc)
> +{
> + int i;
> +
> + for (i = 0; i < NR_MAX_VCHANS; i++) {
> + struct sun6i_vchan *vchan = &sdc->vchans[i];
> +
> + list_del(&vchan->vc.chan.device_node);
> + tasklet_kill(&vchan->vc.task);
> + }
> +
> + tasklet_kill(&sdc->task);
> +}
> +
> +static struct dma_chan *sun6i_dma_of_xlate(struct of_phandle_args *dma_spec,
> + struct of_dma *ofdma)
> +{
> + struct sun6i_dma_dev *sdev = ofdma->of_dma_data;
> + struct sun6i_vchan *vchan;
> + struct dma_chan *chan;
> + u8 port = dma_spec->args[0];
> +
> + if (port > NR_MAX_REQUESTS)
> + return NULL;
> +
> + chan = dma_get_any_slave_channel(&sdev->slave);
> + if (!chan)
> + return NULL;
> +
> + vchan = to_sun6i_vchan(chan);
> + vchan->port = port;
> +
> + return chan;
> +}
> +
> +static int sun6i_dma_probe(struct platform_device *pdev)
> +{
> + struct sun6i_dma_dev *sdc;
> + struct resource *res;
> + struct clk *mux, *pll6;
> + int irq;
> + int ret, i;
> +
> + sdc = devm_kzalloc(&pdev->dev, sizeof(*sdc), GFP_KERNEL);
> + if (!sdc)
> + return -ENOMEM;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + sdc->base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(sdc->base))
> + return PTR_ERR(sdc->base);
> +
> + irq = platform_get_irq(pdev, 0);
> + ret = devm_request_irq(&pdev->dev, irq, sun6i_dma_interrupt, 0,
> + dev_name(&pdev->dev), sdc);
> + if (ret) {
> + dev_err(&pdev->dev, "Cannot request IRQ\n");
> + return ret;
> + }
> +
> + sdc->clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(sdc->clk)) {
> + dev_err(&pdev->dev, "No clock specified\n");
> + return PTR_ERR(sdc->clk);
> + }
> +
> + mux = devm_clk_get(&pdev->dev, "ahb1_mux");
> + if (IS_ERR(mux)) {
> + pr_err("Couldn't get AHB1 Mux\n");
dev_err()
> + return PTR_ERR(mux);
> + }
> +
> + pll6 = devm_clk_get(&pdev->dev, "pll6");
> + if (IS_ERR(pll6)) {
> + pr_err("Couldn't get PLL6\n");
Ditto.
> + return PTR_ERR(pll6);
> + }
> +
> + ret = clk_set_parent(mux, pll6);
> + if (ret) {
> + dev_err(&pdev->dev, "Couldn't reparent AHB1 on PLL6\n");
> + return ret;
> + }
> +
> + devm_clk_put(&pdev->dev, mux);
> + devm_clk_put(&pdev->dev, pll6);
Since you put those here, would it be better to use plain
clk_get/clk_put ?
> +
> + sdc->rstc = devm_reset_control_get(&pdev->dev, NULL);
> + if (IS_ERR(sdc->rstc)) {
> + dev_err(&pdev->dev, "No reset controller specified\n");
> + return PTR_ERR(sdc->rstc);
> + }
> +
> + sdc->pool = dmam_pool_create(dev_name(&pdev->dev), &pdev->dev,
> + sizeof(struct sun6i_dma_lli), 4, 0);
> + if (!sdc->pool) {
> + dev_err(&pdev->dev, "No memory for descriptors dma pool\n");
> + return -ENOMEM;
> + }
> +
> + platform_set_drvdata(pdev, sdc);
> + INIT_LIST_HEAD(&sdc->pending);
> + spin_lock_init(&sdc->lock);
> +
> + dma_cap_set(DMA_PRIVATE, sdc->slave.cap_mask);
> + dma_cap_set(DMA_MEMCPY, sdc->slave.cap_mask);
> + dma_cap_set(DMA_SLAVE, sdc->slave.cap_mask);
> +
> + INIT_LIST_HEAD(&sdc->slave.channels);
> + sdc->slave.device_alloc_chan_resources = sun6i_dma_alloc_chan_resources;
> + sdc->slave.device_free_chan_resources = sun6i_dma_free_chan_resources;
> + sdc->slave.device_tx_status = sun6i_dma_tx_status;
> + sdc->slave.device_issue_pending = sun6i_dma_issue_pending;
> + sdc->slave.device_prep_slave_sg = sun6i_dma_prep_slave_sg;
> + sdc->slave.device_prep_dma_memcpy = sun6i_dma_prep_dma_memcpy;
> + sdc->slave.device_control = sun6i_dma_control;
> + sdc->slave.chancnt = NR_MAX_VCHANS;
> +
> + sdc->slave.dev = &pdev->dev;
> +
> + sdc->pchans = devm_kcalloc(&pdev->dev, NR_MAX_CHANNELS,
> + sizeof(struct sun6i_pchan), GFP_KERNEL);
> + if (!sdc->pchans)
> + return -ENOMEM;
> +
> + sdc->vchans = devm_kcalloc(&pdev->dev, NR_MAX_VCHANS,
> + sizeof(struct sun6i_vchan), GFP_KERNEL);
> + if (!sdc->vchans)
> + return -ENOMEM;
> +
> + tasklet_init(&sdc->task, sun6i_dma_tasklet, (unsigned long)sdc);
> +
> + for (i = 0; i < NR_MAX_CHANNELS; i++) {
> + struct sun6i_pchan *pchan = &sdc->pchans[i];
> +
> + pchan->idx = i;
> + pchan->base = sdc->base + 0x100 + i * 0x40;
> + }
> +
> + for (i = 0; i < NR_MAX_VCHANS; i++) {
> + struct sun6i_vchan *vchan = &sdc->vchans[i];
> +
> + INIT_LIST_HEAD(&vchan->node);
> + vchan->vc.desc_free = sun6i_dma_free_desc;
> + vchan_init(&vchan->vc, &sdc->slave);
> + }
> +
> + ret = reset_control_deassert(sdc->rstc);
> + if (ret) {
> + dev_err(&pdev->dev, "Couldn't deassert the device from reset\n");
> + goto err_chan_free;
> + }
> +
> + ret = clk_prepare_enable(sdc->clk);
> + if (ret) {
> + dev_err(&pdev->dev, "Couldn't enable the clock\n");
> + goto err_reset_assert;
> + }
> +
> + ret = dma_async_device_register(&sdc->slave);
> + if (ret) {
> + dev_warn(&pdev->dev, "Failed to register DMA engine device\n");
> + goto err_clk_disable;
> + }
> +
> + ret = of_dma_controller_register(pdev->dev.of_node, sun6i_dma_of_xlate,
> + sdc);
> + if (ret) {
> + dev_err(&pdev->dev, "of_dma_controller_register failed\n");
> + goto err_dma_unregister;
> + }
> +
> + return 0;
> +
> +err_dma_unregister:
> + dma_async_device_unregister(&sdc->slave);
> +err_clk_disable:
> + clk_disable_unprepare(sdc->clk);
> +err_reset_assert:
> + reset_control_assert(sdc->rstc);
> +err_chan_free:
> + sun6i_dma_free(sdc);
> + return ret;
> +}
> +
> +static int sun6i_dma_remove(struct platform_device *pdev)
> +{
> + struct sun6i_dma_dev *sdc = platform_get_drvdata(pdev);
> +
> + of_dma_controller_free(pdev->dev.of_node);
> + dma_async_device_unregister(&sdc->slave);
> +
> + clk_disable_unprepare(sdc->clk);
> + reset_control_assert(sdc->rstc);
> +
> + sun6i_dma_free(sdc);
> +
> + return 0;
> +}
> +
> +static struct of_device_id sun6i_dma_match[] = {
> + { .compatible = "allwinner,sun6i-a31-dma" }
> +};
> +
> +static struct platform_driver sun6i_dma_driver = {
> + .probe = sun6i_dma_probe,
> + .remove = sun6i_dma_remove,
> + .driver = {
> + .name = "sun6i-dma",
> + .of_match_table = sun6i_dma_match,
> + },
> +};
> +module_platform_driver(sun6i_dma_driver);
> +
> +MODULE_DESCRIPTION("Allwinner A31 DMA Controller Driver");
> +MODULE_AUTHOR("Sugar <shuge@...winnertech.com>");
> +MODULE_AUTHOR("Maxime Ripard <maxime.ripard@...e-electrons.com>");
> +MODULE_LICENSE("GPL");
--
Andy Shevchenko <andriy.shevchenko@...el.com>
Intel Finland Oy
---------------------------------------------------------------------
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