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linux/drivers/dma/stm32-dma.c

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/*
* Driver for STM32 DMA controller
*
* Inspired by dma-jz4740.c and tegra20-apb-dma.c
*
* Copyright (C) M'boumba Cedric Madianga 2015
* Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
*
* License terms: GNU General Public License (GPL), version 2
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/list.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/reset.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include "virt-dma.h"
#define STM32_DMA_LISR 0x0000 /* DMA Low Int Status Reg */
#define STM32_DMA_HISR 0x0004 /* DMA High Int Status Reg */
#define STM32_DMA_LIFCR 0x0008 /* DMA Low Int Flag Clear Reg */
#define STM32_DMA_HIFCR 0x000c /* DMA High Int Flag Clear Reg */
#define STM32_DMA_TCI BIT(5) /* Transfer Complete Interrupt */
#define STM32_DMA_TEI BIT(3) /* Transfer Error Interrupt */
#define STM32_DMA_DMEI BIT(2) /* Direct Mode Error Interrupt */
#define STM32_DMA_FEI BIT(0) /* FIFO Error Interrupt */
/* DMA Stream x Configuration Register */
#define STM32_DMA_SCR(x) (0x0010 + 0x18 * (x)) /* x = 0..7 */
#define STM32_DMA_SCR_REQ(n) ((n & 0x7) << 25)
#define STM32_DMA_SCR_MBURST_MASK GENMASK(24, 23)
#define STM32_DMA_SCR_MBURST(n) ((n & 0x3) << 23)
#define STM32_DMA_SCR_PBURST_MASK GENMASK(22, 21)
#define STM32_DMA_SCR_PBURST(n) ((n & 0x3) << 21)
#define STM32_DMA_SCR_PL_MASK GENMASK(17, 16)
#define STM32_DMA_SCR_PL(n) ((n & 0x3) << 16)
#define STM32_DMA_SCR_MSIZE_MASK GENMASK(14, 13)
#define STM32_DMA_SCR_MSIZE(n) ((n & 0x3) << 13)
#define STM32_DMA_SCR_PSIZE_MASK GENMASK(12, 11)
#define STM32_DMA_SCR_PSIZE(n) ((n & 0x3) << 11)
#define STM32_DMA_SCR_PSIZE_GET(n) ((n & STM32_DMA_SCR_PSIZE_MASK) >> 11)
#define STM32_DMA_SCR_DIR_MASK GENMASK(7, 6)
#define STM32_DMA_SCR_DIR(n) ((n & 0x3) << 6)
#define STM32_DMA_SCR_CT BIT(19) /* Target in double buffer */
#define STM32_DMA_SCR_DBM BIT(18) /* Double Buffer Mode */
#define STM32_DMA_SCR_PINCOS BIT(15) /* Peripheral inc offset size */
#define STM32_DMA_SCR_MINC BIT(10) /* Memory increment mode */
#define STM32_DMA_SCR_PINC BIT(9) /* Peripheral increment mode */
#define STM32_DMA_SCR_CIRC BIT(8) /* Circular mode */
#define STM32_DMA_SCR_PFCTRL BIT(5) /* Peripheral Flow Controller */
#define STM32_DMA_SCR_TCIE BIT(4) /* Transfer Cplete Int Enable*/
#define STM32_DMA_SCR_TEIE BIT(2) /* Transfer Error Int Enable */
#define STM32_DMA_SCR_DMEIE BIT(1) /* Direct Mode Err Int Enable */
#define STM32_DMA_SCR_EN BIT(0) /* Stream Enable */
#define STM32_DMA_SCR_CFG_MASK (STM32_DMA_SCR_PINC \
| STM32_DMA_SCR_MINC \
| STM32_DMA_SCR_PINCOS \
| STM32_DMA_SCR_PL_MASK)
#define STM32_DMA_SCR_IRQ_MASK (STM32_DMA_SCR_TCIE \
| STM32_DMA_SCR_TEIE \
| STM32_DMA_SCR_DMEIE)
/* DMA Stream x number of data register */
#define STM32_DMA_SNDTR(x) (0x0014 + 0x18 * (x))
/* DMA stream peripheral address register */
#define STM32_DMA_SPAR(x) (0x0018 + 0x18 * (x))
/* DMA stream x memory 0 address register */
#define STM32_DMA_SM0AR(x) (0x001c + 0x18 * (x))
/* DMA stream x memory 1 address register */
#define STM32_DMA_SM1AR(x) (0x0020 + 0x18 * (x))
/* DMA stream x FIFO control register */
#define STM32_DMA_SFCR(x) (0x0024 + 0x18 * (x))
#define STM32_DMA_SFCR_FTH_MASK GENMASK(1, 0)
#define STM32_DMA_SFCR_FTH(n) (n & STM32_DMA_SFCR_FTH_MASK)
#define STM32_DMA_SFCR_FEIE BIT(7) /* FIFO error interrupt enable */
#define STM32_DMA_SFCR_DMDIS BIT(2) /* Direct mode disable */
#define STM32_DMA_SFCR_MASK (STM32_DMA_SFCR_FEIE \
| STM32_DMA_SFCR_DMDIS)
/* DMA direction */
#define STM32_DMA_DEV_TO_MEM 0x00
#define STM32_DMA_MEM_TO_DEV 0x01
#define STM32_DMA_MEM_TO_MEM 0x02
/* DMA priority level */
#define STM32_DMA_PRIORITY_LOW 0x00
#define STM32_DMA_PRIORITY_MEDIUM 0x01
#define STM32_DMA_PRIORITY_HIGH 0x02
#define STM32_DMA_PRIORITY_VERY_HIGH 0x03
/* DMA FIFO threshold selection */
#define STM32_DMA_FIFO_THRESHOLD_1QUARTERFULL 0x00
#define STM32_DMA_FIFO_THRESHOLD_HALFFULL 0x01
#define STM32_DMA_FIFO_THRESHOLD_3QUARTERSFULL 0x02
#define STM32_DMA_FIFO_THRESHOLD_FULL 0x03
#define STM32_DMA_MAX_DATA_ITEMS 0xffff
#define STM32_DMA_MAX_CHANNELS 0x08
#define STM32_DMA_MAX_REQUEST_ID 0x08
#define STM32_DMA_MAX_DATA_PARAM 0x03
#define STM32_DMA_MAX_BURST 16
enum stm32_dma_width {
STM32_DMA_BYTE,
STM32_DMA_HALF_WORD,
STM32_DMA_WORD,
};
enum stm32_dma_burst_size {
STM32_DMA_BURST_SINGLE,
STM32_DMA_BURST_INCR4,
STM32_DMA_BURST_INCR8,
STM32_DMA_BURST_INCR16,
};
struct stm32_dma_cfg {
u32 channel_id;
u32 request_line;
u32 stream_config;
u32 threshold;
};
struct stm32_dma_chan_reg {
u32 dma_lisr;
u32 dma_hisr;
u32 dma_lifcr;
u32 dma_hifcr;
u32 dma_scr;
u32 dma_sndtr;
u32 dma_spar;
u32 dma_sm0ar;
u32 dma_sm1ar;
u32 dma_sfcr;
};
struct stm32_dma_sg_req {
u32 len;
struct stm32_dma_chan_reg chan_reg;
};
struct stm32_dma_desc {
struct virt_dma_desc vdesc;
bool cyclic;
u32 num_sgs;
struct stm32_dma_sg_req sg_req[];
};
struct stm32_dma_chan {
struct virt_dma_chan vchan;
bool config_init;
bool busy;
u32 id;
u32 irq;
struct stm32_dma_desc *desc;
u32 next_sg;
struct dma_slave_config dma_sconfig;
struct stm32_dma_chan_reg chan_reg;
};
struct stm32_dma_device {
struct dma_device ddev;
void __iomem *base;
struct clk *clk;
struct reset_control *rst;
bool mem2mem;
struct stm32_dma_chan chan[STM32_DMA_MAX_CHANNELS];
};
static struct stm32_dma_device *stm32_dma_get_dev(struct stm32_dma_chan *chan)
{
return container_of(chan->vchan.chan.device, struct stm32_dma_device,
ddev);
}
static struct stm32_dma_chan *to_stm32_dma_chan(struct dma_chan *c)
{
return container_of(c, struct stm32_dma_chan, vchan.chan);
}
static struct stm32_dma_desc *to_stm32_dma_desc(struct virt_dma_desc *vdesc)
{
return container_of(vdesc, struct stm32_dma_desc, vdesc);
}
static struct device *chan2dev(struct stm32_dma_chan *chan)
{
return &chan->vchan.chan.dev->device;
}
static u32 stm32_dma_read(struct stm32_dma_device *dmadev, u32 reg)
{
return readl_relaxed(dmadev->base + reg);
}
static void stm32_dma_write(struct stm32_dma_device *dmadev, u32 reg, u32 val)
{
writel_relaxed(val, dmadev->base + reg);
}
static struct stm32_dma_desc *stm32_dma_alloc_desc(u32 num_sgs)
{
return kzalloc(sizeof(struct stm32_dma_desc) +
sizeof(struct stm32_dma_sg_req) * num_sgs, GFP_NOWAIT);
}
static int stm32_dma_get_width(struct stm32_dma_chan *chan,
enum dma_slave_buswidth width)
{
switch (width) {
case DMA_SLAVE_BUSWIDTH_1_BYTE:
return STM32_DMA_BYTE;
case DMA_SLAVE_BUSWIDTH_2_BYTES:
return STM32_DMA_HALF_WORD;
case DMA_SLAVE_BUSWIDTH_4_BYTES:
return STM32_DMA_WORD;
default:
dev_err(chan2dev(chan), "Dma bus width not supported\n");
return -EINVAL;
}
}
static int stm32_dma_get_burst(struct stm32_dma_chan *chan, u32 maxburst)
{
switch (maxburst) {
case 0:
case 1:
return STM32_DMA_BURST_SINGLE;
case 4:
return STM32_DMA_BURST_INCR4;
case 8:
return STM32_DMA_BURST_INCR8;
case 16:
return STM32_DMA_BURST_INCR16;
default:
dev_err(chan2dev(chan), "Dma burst size not supported\n");
return -EINVAL;
}
}
static void stm32_dma_set_fifo_config(struct stm32_dma_chan *chan,
u32 src_maxburst, u32 dst_maxburst)
{
chan->chan_reg.dma_sfcr &= ~STM32_DMA_SFCR_MASK;
chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_DMEIE;
if ((!src_maxburst) && (!dst_maxburst)) {
/* Using direct mode */
chan->chan_reg.dma_scr |= STM32_DMA_SCR_DMEIE;
} else {
/* Using FIFO mode */
chan->chan_reg.dma_sfcr |= STM32_DMA_SFCR_MASK;
}
}
static int stm32_dma_slave_config(struct dma_chan *c,
struct dma_slave_config *config)
{
struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
memcpy(&chan->dma_sconfig, config, sizeof(*config));
chan->config_init = true;
return 0;
}
static u32 stm32_dma_irq_status(struct stm32_dma_chan *chan)
{
struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
u32 flags, dma_isr;
/*
* Read "flags" from DMA_xISR register corresponding to the selected
* DMA channel at the correct bit offset inside that register.
*
* If (ch % 4) is 2 or 3, left shift the mask by 16 bits.
* If (ch % 4) is 1 or 3, additionally left shift the mask by 6 bits.
*/
if (chan->id & 4)
dma_isr = stm32_dma_read(dmadev, STM32_DMA_HISR);
else
dma_isr = stm32_dma_read(dmadev, STM32_DMA_LISR);
flags = dma_isr >> (((chan->id & 2) << 3) | ((chan->id & 1) * 6));
return flags;
}
static void stm32_dma_irq_clear(struct stm32_dma_chan *chan, u32 flags)
{
struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
u32 dma_ifcr;
/*
* Write "flags" to the DMA_xIFCR register corresponding to the selected
* DMA channel at the correct bit offset inside that register.
*
* If (ch % 4) is 2 or 3, left shift the mask by 16 bits.
* If (ch % 4) is 1 or 3, additionally left shift the mask by 6 bits.
*/
dma_ifcr = flags << (((chan->id & 2) << 3) | ((chan->id & 1) * 6));
if (chan->id & 4)
stm32_dma_write(dmadev, STM32_DMA_HIFCR, dma_ifcr);
else
stm32_dma_write(dmadev, STM32_DMA_LIFCR, dma_ifcr);
}
static int stm32_dma_disable_chan(struct stm32_dma_chan *chan)
{
struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
unsigned long timeout = jiffies + msecs_to_jiffies(5000);
u32 dma_scr, id;
id = chan->id;
dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
if (dma_scr & STM32_DMA_SCR_EN) {
dma_scr &= ~STM32_DMA_SCR_EN;
stm32_dma_write(dmadev, STM32_DMA_SCR(id), dma_scr);
do {
dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
dma_scr &= STM32_DMA_SCR_EN;
if (!dma_scr)
break;
if (time_after_eq(jiffies, timeout)) {
dev_err(chan2dev(chan), "%s: timeout!\n",
__func__);
return -EBUSY;
}
cond_resched();
} while (1);
}
return 0;
}
static void stm32_dma_stop(struct stm32_dma_chan *chan)
{
struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
u32 dma_scr, dma_sfcr, status;
int ret;
/* Disable interrupts */
dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
dma_scr &= ~STM32_DMA_SCR_IRQ_MASK;
stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), dma_scr);
dma_sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
dma_sfcr &= ~STM32_DMA_SFCR_FEIE;
stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), dma_sfcr);
/* Disable DMA */
ret = stm32_dma_disable_chan(chan);
if (ret < 0)
return;
/* Clear interrupt status if it is there */
status = stm32_dma_irq_status(chan);
if (status) {
dev_dbg(chan2dev(chan), "%s(): clearing interrupt: 0x%08x\n",
__func__, status);
stm32_dma_irq_clear(chan, status);
}
chan->busy = false;
}
static int stm32_dma_terminate_all(struct dma_chan *c)
{
struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
unsigned long flags;
LIST_HEAD(head);
spin_lock_irqsave(&chan->vchan.lock, flags);
if (chan->busy) {
stm32_dma_stop(chan);
chan->desc = NULL;
}
vchan_get_all_descriptors(&chan->vchan, &head);
spin_unlock_irqrestore(&chan->vchan.lock, flags);
vchan_dma_desc_free_list(&chan->vchan, &head);
return 0;
}
static void stm32_dma_synchronize(struct dma_chan *c)
{
struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
vchan_synchronize(&chan->vchan);
}
static void stm32_dma_dump_reg(struct stm32_dma_chan *chan)
{
struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
u32 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
u32 ndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
u32 spar = stm32_dma_read(dmadev, STM32_DMA_SPAR(chan->id));
u32 sm0ar = stm32_dma_read(dmadev, STM32_DMA_SM0AR(chan->id));
u32 sm1ar = stm32_dma_read(dmadev, STM32_DMA_SM1AR(chan->id));
u32 sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
dev_dbg(chan2dev(chan), "SCR: 0x%08x\n", scr);
dev_dbg(chan2dev(chan), "NDTR: 0x%08x\n", ndtr);
dev_dbg(chan2dev(chan), "SPAR: 0x%08x\n", spar);
dev_dbg(chan2dev(chan), "SM0AR: 0x%08x\n", sm0ar);
dev_dbg(chan2dev(chan), "SM1AR: 0x%08x\n", sm1ar);
dev_dbg(chan2dev(chan), "SFCR: 0x%08x\n", sfcr);
}
static void stm32_dma_start_transfer(struct stm32_dma_chan *chan)
{
struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
struct virt_dma_desc *vdesc;
struct stm32_dma_sg_req *sg_req;
struct stm32_dma_chan_reg *reg;
u32 status;
int ret;
ret = stm32_dma_disable_chan(chan);
if (ret < 0)
return;
if (!chan->desc) {
vdesc = vchan_next_desc(&chan->vchan);
if (!vdesc)
return;
chan->desc = to_stm32_dma_desc(vdesc);
chan->next_sg = 0;
}
if (chan->next_sg == chan->desc->num_sgs)
chan->next_sg = 0;
sg_req = &chan->desc->sg_req[chan->next_sg];
reg = &sg_req->chan_reg;
stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
stm32_dma_write(dmadev, STM32_DMA_SPAR(chan->id), reg->dma_spar);
stm32_dma_write(dmadev, STM32_DMA_SM0AR(chan->id), reg->dma_sm0ar);
stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), reg->dma_sfcr);
stm32_dma_write(dmadev, STM32_DMA_SM1AR(chan->id), reg->dma_sm1ar);
stm32_dma_write(dmadev, STM32_DMA_SNDTR(chan->id), reg->dma_sndtr);
chan->next_sg++;
/* Clear interrupt status if it is there */
status = stm32_dma_irq_status(chan);
if (status)
stm32_dma_irq_clear(chan, status);
stm32_dma_dump_reg(chan);
/* Start DMA */
reg->dma_scr |= STM32_DMA_SCR_EN;
stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
chan->busy = true;
dev_dbg(chan2dev(chan), "vchan %p: started\n", &chan->vchan);
}
static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan)
{
struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
struct stm32_dma_sg_req *sg_req;
u32 dma_scr, dma_sm0ar, dma_sm1ar, id;
id = chan->id;
dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
if (dma_scr & STM32_DMA_SCR_DBM) {
if (chan->next_sg == chan->desc->num_sgs)
chan->next_sg = 0;
sg_req = &chan->desc->sg_req[chan->next_sg];
if (dma_scr & STM32_DMA_SCR_CT) {
dma_sm0ar = sg_req->chan_reg.dma_sm0ar;
stm32_dma_write(dmadev, STM32_DMA_SM0AR(id), dma_sm0ar);
dev_dbg(chan2dev(chan), "CT=1 <=> SM0AR: 0x%08x\n",
stm32_dma_read(dmadev, STM32_DMA_SM0AR(id)));
} else {
dma_sm1ar = sg_req->chan_reg.dma_sm1ar;
stm32_dma_write(dmadev, STM32_DMA_SM1AR(id), dma_sm1ar);
dev_dbg(chan2dev(chan), "CT=0 <=> SM1AR: 0x%08x\n",
stm32_dma_read(dmadev, STM32_DMA_SM1AR(id)));
}
}
}
static void stm32_dma_handle_chan_done(struct stm32_dma_chan *chan)
{
if (chan->desc) {
if (chan->desc->cyclic) {
vchan_cyclic_callback(&chan->desc->vdesc);
chan->next_sg++;
stm32_dma_configure_next_sg(chan);
} else {
chan->busy = false;
if (chan->next_sg == chan->desc->num_sgs) {
list_del(&chan->desc->vdesc.node);
vchan_cookie_complete(&chan->desc->vdesc);
chan->desc = NULL;
}
stm32_dma_start_transfer(chan);
}
}
}
static irqreturn_t stm32_dma_chan_irq(int irq, void *devid)
{
struct stm32_dma_chan *chan = devid;
struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
u32 status, scr;
spin_lock(&chan->vchan.lock);
status = stm32_dma_irq_status(chan);
scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
if ((status & STM32_DMA_TCI) && (scr & STM32_DMA_SCR_TCIE)) {
stm32_dma_irq_clear(chan, STM32_DMA_TCI);
stm32_dma_handle_chan_done(chan);
} else {
stm32_dma_irq_clear(chan, status);
dev_err(chan2dev(chan), "DMA error: status=0x%08x\n", status);
}
spin_unlock(&chan->vchan.lock);
return IRQ_HANDLED;
}
static void stm32_dma_issue_pending(struct dma_chan *c)
{
struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
unsigned long flags;
spin_lock_irqsave(&chan->vchan.lock, flags);
if (vchan_issue_pending(&chan->vchan) && !chan->desc && !chan->busy) {
dev_dbg(chan2dev(chan), "vchan %p: issued\n", &chan->vchan);
stm32_dma_start_transfer(chan);
if (chan->desc->cyclic)
stm32_dma_configure_next_sg(chan);
}
spin_unlock_irqrestore(&chan->vchan.lock, flags);
}
static int stm32_dma_set_xfer_param(struct stm32_dma_chan *chan,
enum dma_transfer_direction direction,
enum dma_slave_buswidth *buswidth)
{
enum dma_slave_buswidth src_addr_width, dst_addr_width;
int src_bus_width, dst_bus_width;
int src_burst_size, dst_burst_size;
u32 src_maxburst, dst_maxburst;
u32 dma_scr = 0;
src_addr_width = chan->dma_sconfig.src_addr_width;
dst_addr_width = chan->dma_sconfig.dst_addr_width;
src_maxburst = chan->dma_sconfig.src_maxburst;
dst_maxburst = chan->dma_sconfig.dst_maxburst;
switch (direction) {
case DMA_MEM_TO_DEV:
dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
if (dst_bus_width < 0)
return dst_bus_width;
dst_burst_size = stm32_dma_get_burst(chan, dst_maxburst);
if (dst_burst_size < 0)
return dst_burst_size;
if (!src_addr_width)
src_addr_width = dst_addr_width;
src_bus_width = stm32_dma_get_width(chan, src_addr_width);
if (src_bus_width < 0)
return src_bus_width;
src_burst_size = stm32_dma_get_burst(chan, src_maxburst);
if (src_burst_size < 0)
return src_burst_size;
dma_scr = STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_DEV) |
STM32_DMA_SCR_PSIZE(dst_bus_width) |
STM32_DMA_SCR_MSIZE(src_bus_width) |
STM32_DMA_SCR_PBURST(dst_burst_size) |
STM32_DMA_SCR_MBURST(src_burst_size);
chan->chan_reg.dma_spar = chan->dma_sconfig.dst_addr;
*buswidth = dst_addr_width;
break;
case DMA_DEV_TO_MEM:
src_bus_width = stm32_dma_get_width(chan, src_addr_width);
if (src_bus_width < 0)
return src_bus_width;
src_burst_size = stm32_dma_get_burst(chan, src_maxburst);
if (src_burst_size < 0)
return src_burst_size;
if (!dst_addr_width)
dst_addr_width = src_addr_width;
dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
if (dst_bus_width < 0)
return dst_bus_width;
dst_burst_size = stm32_dma_get_burst(chan, dst_maxburst);
if (dst_burst_size < 0)
return dst_burst_size;
dma_scr = STM32_DMA_SCR_DIR(STM32_DMA_DEV_TO_MEM) |
STM32_DMA_SCR_PSIZE(src_bus_width) |
STM32_DMA_SCR_MSIZE(dst_bus_width) |
STM32_DMA_SCR_PBURST(src_burst_size) |
STM32_DMA_SCR_MBURST(dst_burst_size);
chan->chan_reg.dma_spar = chan->dma_sconfig.src_addr;
*buswidth = chan->dma_sconfig.src_addr_width;
break;
default:
dev_err(chan2dev(chan), "Dma direction is not supported\n");
return -EINVAL;
}
stm32_dma_set_fifo_config(chan, src_maxburst, dst_maxburst);
chan->chan_reg.dma_scr &= ~(STM32_DMA_SCR_DIR_MASK |
STM32_DMA_SCR_PSIZE_MASK | STM32_DMA_SCR_MSIZE_MASK |
STM32_DMA_SCR_PBURST_MASK | STM32_DMA_SCR_MBURST_MASK);
chan->chan_reg.dma_scr |= dma_scr;
return 0;
}
static void stm32_dma_clear_reg(struct stm32_dma_chan_reg *regs)
{
memset(regs, 0, sizeof(struct stm32_dma_chan_reg));
}
static struct dma_async_tx_descriptor *stm32_dma_prep_slave_sg(
struct dma_chan *c, struct scatterlist *sgl,
u32 sg_len, enum dma_transfer_direction direction,
unsigned long flags, void *context)
{
struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
struct stm32_dma_desc *desc;
struct scatterlist *sg;
enum dma_slave_buswidth buswidth;
u32 nb_data_items;
int i, ret;
if (!chan->config_init) {
dev_err(chan2dev(chan), "dma channel is not configured\n");
return NULL;
}
if (sg_len < 1) {
dev_err(chan2dev(chan), "Invalid segment length %d\n", sg_len);
return NULL;
}
desc = stm32_dma_alloc_desc(sg_len);
if (!desc)
return NULL;
ret = stm32_dma_set_xfer_param(chan, direction, &buswidth);
if (ret < 0)
goto err;
/* Set peripheral flow controller */
if (chan->dma_sconfig.device_fc)
chan->chan_reg.dma_scr |= STM32_DMA_SCR_PFCTRL;
else
chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
for_each_sg(sgl, sg, sg_len, i) {
desc->sg_req[i].len = sg_dma_len(sg);
nb_data_items = desc->sg_req[i].len / buswidth;
if (nb_data_items > STM32_DMA_MAX_DATA_ITEMS) {
dev_err(chan2dev(chan), "nb items not supported\n");
goto err;
}
stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
desc->sg_req[i].chan_reg.dma_sm0ar = sg_dma_address(sg);
desc->sg_req[i].chan_reg.dma_sm1ar = sg_dma_address(sg);
desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
}
desc->num_sgs = sg_len;
desc->cyclic = false;
return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
err:
kfree(desc);
return NULL;
}
static struct dma_async_tx_descriptor *stm32_dma_prep_dma_cyclic(
struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len,
size_t period_len, enum dma_transfer_direction direction,
unsigned long flags)
{
struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
struct stm32_dma_desc *desc;
enum dma_slave_buswidth buswidth;
u32 num_periods, nb_data_items;
int i, ret;
if (!buf_len || !period_len) {
dev_err(chan2dev(chan), "Invalid buffer/period len\n");
return NULL;
}
if (!chan->config_init) {
dev_err(chan2dev(chan), "dma channel is not configured\n");
return NULL;
}
if (buf_len % period_len) {
dev_err(chan2dev(chan), "buf_len not multiple of period_len\n");
return NULL;
}
/*
* We allow to take more number of requests till DMA is
* not started. The driver will loop over all requests.
* Once DMA is started then new requests can be queued only after
* terminating the DMA.
*/
if (chan->busy) {
dev_err(chan2dev(chan), "Request not allowed when dma busy\n");
return NULL;
}
ret = stm32_dma_set_xfer_param(chan, direction, &buswidth);
if (ret < 0)
return NULL;
nb_data_items = period_len / buswidth;
if (nb_data_items > STM32_DMA_MAX_DATA_ITEMS) {
dev_err(chan2dev(chan), "number of items not supported\n");
return NULL;
}
/* Enable Circular mode or double buffer mode */
if (buf_len == period_len)
chan->chan_reg.dma_scr |= STM32_DMA_SCR_CIRC;
else
chan->chan_reg.dma_scr |= STM32_DMA_SCR_DBM;
/* Clear periph ctrl if client set it */
chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
num_periods = buf_len / period_len;
desc = stm32_dma_alloc_desc(num_periods);
if (!desc)
return NULL;
for (i = 0; i < num_periods; i++) {
desc->sg_req[i].len = period_len;
stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
desc->sg_req[i].chan_reg.dma_sm0ar = buf_addr;
desc->sg_req[i].chan_reg.dma_sm1ar = buf_addr;
desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
buf_addr += period_len;
}
desc->num_sgs = num_periods;
desc->cyclic = true;
return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
}
static struct dma_async_tx_descriptor *stm32_dma_prep_dma_memcpy(
struct dma_chan *c, dma_addr_t dest,
dma_addr_t src, size_t len, unsigned long flags)
{
struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
u32 num_sgs;
struct stm32_dma_desc *desc;
size_t xfer_count, offset;
int i;
num_sgs = DIV_ROUND_UP(len, STM32_DMA_MAX_DATA_ITEMS);
desc = stm32_dma_alloc_desc(num_sgs);
if (!desc)
return NULL;
for (offset = 0, i = 0; offset < len; offset += xfer_count, i++) {
xfer_count = min_t(size_t, len - offset,
STM32_DMA_MAX_DATA_ITEMS);
desc->sg_req[i].len = xfer_count;
stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
desc->sg_req[i].chan_reg.dma_scr =
STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_MEM) |
STM32_DMA_SCR_MINC |
STM32_DMA_SCR_PINC |
STM32_DMA_SCR_TCIE |
STM32_DMA_SCR_TEIE;
desc->sg_req[i].chan_reg.dma_sfcr = STM32_DMA_SFCR_DMDIS |
STM32_DMA_SFCR_FTH(STM32_DMA_FIFO_THRESHOLD_FULL) |
STM32_DMA_SFCR_FEIE;
desc->sg_req[i].chan_reg.dma_spar = src + offset;
desc->sg_req[i].chan_reg.dma_sm0ar = dest + offset;
desc->sg_req[i].chan_reg.dma_sndtr = xfer_count;
}
desc->num_sgs = num_sgs;
desc->cyclic = false;
return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
}
static u32 stm32_dma_get_remaining_bytes(struct stm32_dma_chan *chan)
{
u32 dma_scr, width, ndtr;
struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
width = STM32_DMA_SCR_PSIZE_GET(dma_scr);
ndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
return ndtr << width;
}
static size_t stm32_dma_desc_residue(struct stm32_dma_chan *chan,
struct stm32_dma_desc *desc,
u32 next_sg)
{
u32 residue = 0;
int i;
/*
* In cyclic mode, for the last period, residue = remaining bytes from
* NDTR
*/
if (chan->desc->cyclic && next_sg == 0)
return stm32_dma_get_remaining_bytes(chan);
/*
* For all other periods in cyclic mode, and in sg mode,
* residue = remaining bytes from NDTR + remaining periods/sg to be
* transferred
*/
for (i = next_sg; i < desc->num_sgs; i++)
residue += desc->sg_req[i].len;
residue += stm32_dma_get_remaining_bytes(chan);
return residue;
}
static enum dma_status stm32_dma_tx_status(struct dma_chan *c,
dma_cookie_t cookie,
struct dma_tx_state *state)
{
struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
struct virt_dma_desc *vdesc;
enum dma_status status;
unsigned long flags;
u32 residue = 0;
status = dma_cookie_status(c, cookie, state);
if ((status == DMA_COMPLETE) || (!state))
return status;
spin_lock_irqsave(&chan->vchan.lock, flags);
vdesc = vchan_find_desc(&chan->vchan, cookie);
if (chan->desc && cookie == chan->desc->vdesc.tx.cookie)
residue = stm32_dma_desc_residue(chan, chan->desc,
chan->next_sg);
else if (vdesc)
residue = stm32_dma_desc_residue(chan,
to_stm32_dma_desc(vdesc), 0);
dma_set_residue(state, residue);
spin_unlock_irqrestore(&chan->vchan.lock, flags);
return status;
}
static int stm32_dma_alloc_chan_resources(struct dma_chan *c)
{
struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
int ret;
chan->config_init = false;
ret = clk_prepare_enable(dmadev->clk);
if (ret < 0) {
dev_err(chan2dev(chan), "clk_prepare_enable failed: %d\n", ret);
return ret;
}
ret = stm32_dma_disable_chan(chan);
if (ret < 0)
clk_disable_unprepare(dmadev->clk);
return ret;
}
static void stm32_dma_free_chan_resources(struct dma_chan *c)
{
struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
unsigned long flags;
dev_dbg(chan2dev(chan), "Freeing channel %d\n", chan->id);
if (chan->busy) {
spin_lock_irqsave(&chan->vchan.lock, flags);
stm32_dma_stop(chan);
chan->desc = NULL;
spin_unlock_irqrestore(&chan->vchan.lock, flags);
}
clk_disable_unprepare(dmadev->clk);
vchan_free_chan_resources(to_virt_chan(c));
}
static void stm32_dma_desc_free(struct virt_dma_desc *vdesc)
{
kfree(container_of(vdesc, struct stm32_dma_desc, vdesc));
}
static void stm32_dma_set_config(struct stm32_dma_chan *chan,
struct stm32_dma_cfg *cfg)
{
stm32_dma_clear_reg(&chan->chan_reg);
chan->chan_reg.dma_scr = cfg->stream_config & STM32_DMA_SCR_CFG_MASK;
chan->chan_reg.dma_scr |= STM32_DMA_SCR_REQ(cfg->request_line);
/* Enable Interrupts */
chan->chan_reg.dma_scr |= STM32_DMA_SCR_TEIE | STM32_DMA_SCR_TCIE;
chan->chan_reg.dma_sfcr = cfg->threshold & STM32_DMA_SFCR_FTH_MASK;
}
static struct dma_chan *stm32_dma_of_xlate(struct of_phandle_args *dma_spec,
struct of_dma *ofdma)
{
struct stm32_dma_device *dmadev = ofdma->of_dma_data;
struct device *dev = dmadev->ddev.dev;
struct stm32_dma_cfg cfg;
struct stm32_dma_chan *chan;
struct dma_chan *c;
if (dma_spec->args_count < 4) {
dev_err(dev, "Bad number of cells\n");
return NULL;
}
cfg.channel_id = dma_spec->args[0];
cfg.request_line = dma_spec->args[1];
cfg.stream_config = dma_spec->args[2];
cfg.threshold = dma_spec->args[3];
if ((cfg.channel_id >= STM32_DMA_MAX_CHANNELS) ||
(cfg.request_line >= STM32_DMA_MAX_REQUEST_ID)) {
dev_err(dev, "Bad channel and/or request id\n");
return NULL;
}
chan = &dmadev->chan[cfg.channel_id];
c = dma_get_slave_channel(&chan->vchan.chan);
if (!c) {
dev_err(dev, "No more channels available\n");
return NULL;
}
stm32_dma_set_config(chan, &cfg);
return c;
}
static const struct of_device_id stm32_dma_of_match[] = {
{ .compatible = "st,stm32-dma", },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, stm32_dma_of_match);
static int stm32_dma_probe(struct platform_device *pdev)
{
struct stm32_dma_chan *chan;
struct stm32_dma_device *dmadev;
struct dma_device *dd;
const struct of_device_id *match;
struct resource *res;
int i, ret;
match = of_match_device(stm32_dma_of_match, &pdev->dev);
if (!match) {
dev_err(&pdev->dev, "Error: No device match found\n");
return -ENODEV;
}
dmadev = devm_kzalloc(&pdev->dev, sizeof(*dmadev), GFP_KERNEL);
if (!dmadev)
return -ENOMEM;
dd = &dmadev->ddev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
dmadev->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(dmadev->base))
return PTR_ERR(dmadev->base);
dmadev->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(dmadev->clk)) {
dev_err(&pdev->dev, "Error: Missing controller clock\n");
return PTR_ERR(dmadev->clk);
}
dmadev->mem2mem = of_property_read_bool(pdev->dev.of_node,
"st,mem2mem");
dmadev->rst = devm_reset_control_get(&pdev->dev, NULL);
if (!IS_ERR(dmadev->rst)) {
reset_control_assert(dmadev->rst);
udelay(2);
reset_control_deassert(dmadev->rst);
}
dma_cap_set(DMA_SLAVE, dd->cap_mask);
dma_cap_set(DMA_PRIVATE, dd->cap_mask);
dma_cap_set(DMA_CYCLIC, dd->cap_mask);
dd->device_alloc_chan_resources = stm32_dma_alloc_chan_resources;
dd->device_free_chan_resources = stm32_dma_free_chan_resources;
dd->device_tx_status = stm32_dma_tx_status;
dd->device_issue_pending = stm32_dma_issue_pending;
dd->device_prep_slave_sg = stm32_dma_prep_slave_sg;
dd->device_prep_dma_cyclic = stm32_dma_prep_dma_cyclic;
dd->device_config = stm32_dma_slave_config;
dd->device_terminate_all = stm32_dma_terminate_all;
dd->device_synchronize = stm32_dma_synchronize;
dd->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
dd->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
dd->max_burst = STM32_DMA_MAX_BURST;
dd->dev = &pdev->dev;
INIT_LIST_HEAD(&dd->channels);
if (dmadev->mem2mem) {
dma_cap_set(DMA_MEMCPY, dd->cap_mask);
dd->device_prep_dma_memcpy = stm32_dma_prep_dma_memcpy;
dd->directions |= BIT(DMA_MEM_TO_MEM);
}
for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
chan = &dmadev->chan[i];
chan->id = i;
chan->vchan.desc_free = stm32_dma_desc_free;
vchan_init(&chan->vchan, dd);
}
ret = dma_async_device_register(dd);
if (ret)
return ret;
for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
chan = &dmadev->chan[i];
res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
if (!res) {
ret = -EINVAL;
dev_err(&pdev->dev, "No irq resource for chan %d\n", i);
goto err_unregister;
}
chan->irq = res->start;
ret = devm_request_irq(&pdev->dev, chan->irq,
stm32_dma_chan_irq, 0,
dev_name(chan2dev(chan)), chan);
if (ret) {
dev_err(&pdev->dev,
"request_irq failed with err %d channel %d\n",
ret, i);
goto err_unregister;
}
}
ret = of_dma_controller_register(pdev->dev.of_node,
stm32_dma_of_xlate, dmadev);
if (ret < 0) {
dev_err(&pdev->dev,
"STM32 DMA DMA OF registration failed %d\n", ret);
goto err_unregister;
}
platform_set_drvdata(pdev, dmadev);
dev_info(&pdev->dev, "STM32 DMA driver registered\n");
return 0;
err_unregister:
dma_async_device_unregister(dd);
return ret;
}
static struct platform_driver stm32_dma_driver = {
.driver = {
.name = "stm32-dma",
.of_match_table = stm32_dma_of_match,
},
};
static int __init stm32_dma_init(void)
{
return platform_driver_probe(&stm32_dma_driver, stm32_dma_probe);
}
subsys_initcall(stm32_dma_init);
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