This patch adds support for the STM32 DMA controller.
Signed-off-by: M'boumba Cedric Madianga <cedric.madia...@gmail.com>
---
drivers/dma/Kconfig | 12 +
drivers/dma/Makefile | 1 +
drivers/dma/stm32-dma.c | 1141 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 1154 insertions(+)
create mode 100644 drivers/dma/stm32-dma.c
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index af81a7a..b1a071b 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -431,6 +431,18 @@ config STE_DMA40
help
Support for ST-Ericsson DMA40 controller
+config STM32_DMA
+ bool "STMicroelectronics STM32 DMA support"
+ depends on ARCH_STM32
+ select DMA_ENGINE
+ select DMA_OF
+ select DMA_VIRTUAL_CHANNELS
+ help
+ Enable support for the on-chip DMA controller on STMicroelectronics
+ STM32 MCUs.
+ If you have a board based on such a MCU and wish to use DMA say Y or M
+ here.
+
config S3C24XX_DMAC
tristate "Samsung S3C24XX DMA support"
depends on ARCH_S3C24XX
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index ef9c099..2dd0a067 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -56,6 +56,7 @@ obj-$(CONFIG_QCOM_BAM_DMA) += qcom_bam_dma.o
obj-$(CONFIG_RENESAS_DMA) += sh/
obj-$(CONFIG_SIRF_DMA) += sirf-dma.o
obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o
+obj-$(CONFIG_STM32_DMA) += stm32-dma.o
obj-$(CONFIG_S3C24XX_DMAC) += s3c24xx-dma.o
obj-$(CONFIG_TXX9_DMAC) += txx9dmac.o
obj-$(CONFIG_TEGRA20_APB_DMA) += tegra20-apb-dma.o
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
new file mode 100644
index 0000000..12f3a3e
--- /dev/null
+++ b/drivers/dma/stm32-dma.c
@@ -0,0 +1,1141 @@
+/*
+ * 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.madia...@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
+
+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_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 int 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 ret;
+
+ if (!chan->desc) {
+ vdesc = vchan_next_desc(&chan->vchan);
+ if (!vdesc)
+ return 0;
+
+ 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;
+
+ return 0;
+}
+
+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)));
+ }
+
+ chan->next_sg++;
+ }
+}
+
+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);
+ 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, sfcr;
+
+ spin_lock(&chan->vchan.lock);
+
+ status = stm32_dma_irq_status(chan);
+ scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
+ sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(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;
+ int ret;
+
+ spin_lock_irqsave(&chan->vchan.lock, flags);
+ if (!chan->busy) {
+ if (vchan_issue_pending(&chan->vchan) && !chan->desc) {
+ ret = stm32_dma_start_transfer(chan);
+ if ((chan->desc->cyclic) && (!ret))
+ 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;
+ dma_addr_t src_addr, dst_addr;
+ 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;
+ src_addr = chan->dma_sconfig.src_addr;
+ dst_addr = chan->dma_sconfig.dst_addr;
+
+ 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 size_t stm32_dma_desc_residue(struct stm32_dma_chan *chan,
+ struct stm32_dma_desc *desc,
+ u32 next_sg)
+{
+ struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
+ u32 dma_scr, width, residue, count;
+ int i;
+
+ residue = 0;
+
+ for (i = next_sg; i < desc->num_sgs; i++)
+ residue += desc->sg_req[i].len;
+
+ if (next_sg != 0) {
+ dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
+ width = STM32_DMA_SCR_PSIZE_GET(dma_scr);
+ count = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
+
+ residue += count << width;
+ }
+
+ 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;
+
+ 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 (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);
+ } else {
+ residue = 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));
+}
+
+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 stm32_dma_cfg cfg;
+ struct stm32_dma_chan *chan;
+ struct dma_chan *c;
+
+ if (dma_spec->args_count < 3)
+ 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 = 0;
+
+ if ((cfg.channel_id >= STM32_DMA_MAX_CHANNELS) || (cfg.request_line >=
+ STM32_DMA_MAX_REQUEST_ID))
+ return NULL;
+
+ if (dma_spec->args_count > 3)
+ cfg.threshold = dma_spec->args[3];
+
+ chan = &dmadev->chan[cfg.channel_id];
+
+ c = dma_get_slave_channel(&chan->vchan.chan);
+ if (c)
+ 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->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->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);
--
1.9.1
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